December 2021
Efficacy of Lung-Tuned Monopole Antenna for Microwave Ablations: Analytical Solution and Validation in a Ventilator-Controlled Ex Vivo Porcine Lung ModelThe goal of this study was to optimize a lung-tuned monopole antenna to deliver microwave energy at 2.45 GHz into a novel ventilator-controlled ex vivo lung model. An analytic\approach was utilized to create an optimized monopole antenna that was impedance-matched to aerated lung tissue. This lung-tuned antenna was then fabricated using a copper 0.085" semi-rigid copper coaxial cable. For validation, the lung-tuned antenna was inserted centrally into lobes of a ex vivo porcine lung that was fully inflated to physiologically appropriate volumes. Microwave ablations were then created at 50 and 100 W for 1 minute and 5 minutes. Reflected power, cross sectional ablation sizes and spherical shape of the lung-tuned antenna were compared against a liver-tuned antenna in the ventilator-controlled ex vivo lung tissue.
December 2021
Gynecologic Tumor Board: a Radiologist's Guide to Vulvar and Vaginal Malignancies.Primary vulvar and vaginal cancers are rare female genital tract malignancies which are staged using the 2009 International Federation of Gynecology and Obstetrics (FIGO) staging. These cancers account for approximately 2,700 deaths annually in the USA. The most common histologic subtype of both vulvar and vaginal cancers is squamous cell carcinoma, with an increasing role of the human papillomavirus (HPV) in a significant number of these tumors. Lymph node involvement is the hallmark of FIGO stage 3 vulvar cancer while pelvic sidewall involvement is the hallmark of FIGO stage 3 vaginal cancer. Imaging techniques include computed tomography (CT), positron emission tomography (PET)-CT, magnetic resonance imaging (MRI), and PET-MRI. MRI is the imaging modality of choice for preoperative clinical staging of nodal and metastatic involvement while PET-CT is helpful with assessing response to neoadjuvant treatment and for guiding patient management. Determining the pretreatment extent of disease has become more important due to modern tailored operative approaches and use of neoadjuvant chemoradiation therapy to reduce surgical morbidity. Moreover, imaging is used to determine the full extent of disease for radiation planning and for evaluating treatment response. Understanding the relevant anatomy of the vulva and vaginal regions and the associated lymphatic pathways is helpful to recognize the potential routes of spread and to correctly identify the appropriate FIGO stage. The purpose of this article is to review the clinical features, pathology, and current treatment strategies for vulvar and vaginal malignancies and to identify multimodality diagnostic imaging features of these gynecologic cancers, in conjunction with its respective 2009 FIGO staging system guidelines.
December 2021
Superficial Angiomyxoma of the Breast in a 16-year-old Girl without Carney's Complex: A Case Report.Superficial angiomyxoma (SA) is a rare benign soft-tissue tumor, arising sporadically or as the earliest manifestation of Carney's complex. When it arises sporadically, the breast is infrequently involved with only few cases reported in the literature. Key imaging findings include T2 signal hyperintensity on MRI and hypervascularity. In this study, we report the clinical, radiological, surgical, and histopathologic findings of a case of sporadic SA of the breast in a 16-year-old girl.
December 2021
Validation of Diffusion MRI as a Biomarker for Efficacy Using Randomized Phase III Trial of Bevacizumab With or Without VB-111 in Recurrent Glioblastoma.BACKGROUND: Evidence from single and multicenter phase II trials have suggested diffusion MRI is a predictive imaging biomarker for survival benefit in recurrent glioblastoma (rGBM) treated with anti-VEGF therapy. The current study confirms these findings in a large, randomized phase III clinical trial. METHODS: Patients with rGBM were enrolled in a phase III randomized (1:1), controlled trial (NCT02511405) to compare the efficacy and safety of bevacizumab (BV) versus BV in combination with ofranergene obadenovec (BV+VB-111), an anti-cancer viral therapy. In 170 patients with diffusion MRI available, pretreatment enhancing tumor volume and ADC histogram analysis were used to phenotype patients as having high (>1.24 µm2/ms) or low (<1.24 µm2/ms) ADCL, the mean value of the lower peak of the ADC histogram, within the contrast enhancing tumor.
December 2021
"Aerobic Glycolytic Imaging" of Human Gliomas Using Combined pH-, Oxygen-, and Perfusion-weighted Magnetic Resonance Imaging.PURPOSE: To quantify abnormal metabolism of diffuse gliomas using "aerobic glycolytic imaging" and investigate its biological correlation. METHODS: All subjects underwent a pH-weighted amine chemical exchange saturation transfer spin-and-gradient-echo echoplanar imaging (CEST-SAGE-EPI) and dynamic susceptibility contrast perfusion MRI. Relative oxygen extraction fraction (rOEF) was estimated as the ratio of reversible transverse relaxation rate R2' to normalized relative cerebral blood volume. An aerobic glycolytic index (AGI) was derived by the ratio of pH-weighted image contrast (MTRasym at 3.0 ppm) to rOEF. AGI was compared between different tumor types (N = 51, 30 IDH mutant and 21 IDH wild type). Metabolic MR parameters were correlated with 18F-FDG uptake (N = 8, IDH wild-type glioblastoma), expression of key glycolytic proteins using immunohistochemistry (N = 38 samples, 21 from IDH mutant and 17 from IDH wild type), and bioenergetics analysis on purified tumor cells (N = 7, IDH wild-type high grade).
December 2021
Generalizability and Transportability of the National Lung Screening Trial Data: Extending Trial Results to Different Populations.BACKGROUND: Randomized controlled trials (RCT) play a central role in evidence-based healthcare. However, the clinical and policy implications of implementing RCTs in clinical practice are difficult to predict as the studied population is often different from the target population where results are being applied. This study illustrates the concepts of generalizability and transportability, demonstrating their utility in interpreting results from the National Lung Screening Trial (NLST). METHODS: Using inverse-odds weighting, we demonstrate how generalizability and transportability techniques can be used to extrapolate treatment effect from (i) a subset of NLST to the entire NLST population and from (ii) the entire NLST to different target populations.
December 2021
Mechanical Thrombectomy of COVID-19 DVT with Congenital Heart Disease Leading to Phlegmasia Cerulea Dolens: a Case Report.BACKGROUND: COVID-19 and Fontan physiology have each been associated with an elevated risk of venous thromboembolism (VTE), however little is known about the risks and potential consequences of having both. CASE PRESENTATION: A 51 year old male with tricuspid atresia status post Fontan and extracardiac Glenn shunt, atrial flutter, and sinus sick syndrome presented with phlegmasia cerulea dolens (PCD) of the left lower extremity in spite of supratherapeutic INR in the context of symptomatic COVID-10 pneumonia. He was treated with single session, catheter directed mechanical thrombectomy that was well-tolerated.
December 2021
COVID-19 Pandemic Revisited: Lessons the Radiology Community Has Learned a Year Later.For more than 1 year, COVID-19 pandemic has impacted every aspect of our lives. This paper reviews the major challenges that the radiology community faced over the past year and the impact the pandemic had on the radiology practice, radiologist-in-training education, and radiology research. The lessons learned from COVID-19 pandemic can help the radiology community to be prepared for future outbreaks and new pandemics, preserve good habits, enhance cancer screening programs, and adapt to the changes in radiology education and scientific meetings.
December 2021
Relationship Between Superior Semicircular Canal Dehiscence Volume with Clinical Symptoms: Case Series.BACKGROUND: Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrosal temporal bone. Patients typically present with auditory and vestibular symptoms, such as hearing loss and disequilibrium. Using advanced imaging segmentation techniques, we evaluated whether the volume of SSCD correlated with preoperative symptoms and postoperative outcomes. METHODS: Our laboratory previously described a novel method of quantifying the size of an SSCD via manual segmentation. High-resolution computed tomography images of the temporal bones were imported into a specialized segmentation software. The volume of the dehiscence was outlined on consecutive slices of the coronal and axial planes via a single-pixel-thick paintbrush tool and was then calculated according to the number of nonzero image voxels.
December 2021
Consensus Guidelines for the Definition of Time-to-Event End Points in Image-guided Tumor Ablation: Results of the SIO and DATECAN Initiative.There is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue.
December 2021
The Reliability of 3-T Magnetic Resonance Imaging to Identify Arthroscopic Features of Meniscal Tears and Its Utility to Predict Meniscal Tear Reparability.BACKGROUND: The ability to predict meniscus tear reparability based on preoperative magnetic resonance imaging (MRI) is desirable for postoperative planning; however, the accuracy of predictive methods varies widely within the orthopaedic and radiology literature. PURPOSE/HYPOTHESIS: The purpose was to determine if the higher resolution offered by 3-T MRI improves the accuracy of predicting reparability compared with previous investigations using 1.5-T MRI. Our hypothesis was that a higher field strength of 3-T MRI would result in improved reliability assessments and predictions of meniscus tear reparability compared with previous studies utilizing a 1.5-T MRI platform. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 44 patients who underwent meniscus repair were matched by age, sex, and body mass index to 43 patients who underwent partial meniscectomy. Overall, 2 orthopaedic surgeons and 2 musculoskeletal radiologists independently and blindly reviewed the preoperative MRI scans for all 87 patients. For each meniscus tear, reviewers evaluated the following criteria: tear pattern, tear length, tear distance from the meniscocapsular junction, tear thickness, and integrity of any inner meniscal fragment. The resultant data were then applied to 5 different approaches for predicting meniscal reparability.
December 2021
Management of Biliary Stricture in Pediatric Liver Transplantation Patients: Long-Term Outcomes.Postoperative biliary complications have been reported to occur in 10% to 33% of pediatric liver transplantation (LT) recipients. Percutaneous intervention has become the primary treatment method for these complications; however, the efficacy and outcomes of these patients have not been well studied. Institutional pediatric LT from 1998 to 2019 were retrospectively reviewed to determine the patients referred for percutaneous treatment of post-LT biliary strictures. Clinical parameters, percutaneous transhepatic cholangiograms (PTCs), biliary catheter placement, cholangioplasty, and long-term outcomes were analyzed. Of the 396 consecutive pediatric LT recipients during our study period, 50 (12.6%) were diagnosed with biliary strictures on PTC. LT biliary reconstructions were Roux-en-Y hepaticojejunostomy in 28 patients (56%), choledochojejunostomy in 11 patients (22%), and choledochocholedochostomy in 11 patients (22%). Median age at LT was 23.2 months (interquartile range [IQR], 10.9-90.6), and 14 patients (28%) developed hepatic artery thrombosis. A total of 44 patients (88%) were treated with internal/external biliary catheters, of whom 38 (76%) underwent balloon cholangioplasty. By 12 months, 84% of patients had complete stricture resolution and catheter removal. Median total duration of catheter drainage was 152 days (IQR, 76-308). A total of 8 patients required additional surgery (biliary reconstruction or repeat LT [re-LT]) or died with a drainage catheter in place from complications unrelated to PTC intervention. Among the 6 patients (12%) treated with unilateral external biliary drainage catheters, 2 had catheters removed for inadequate drainage but then had spontaneous biliary obstruction resolution, 1 underwent duct reconstruction, and 3 required long-term catheterization. Biliary strictures following pediatric LT can be successfully treated with internal/external biliary drainage catheters and cholangioplasty if the stricture can be crossed. However, patients with isolated strictured ducts may require long-term external catheter drainage until re-LT or percutaneous obliteration of isolated ducts.
November 2021
AngioVac Aspiration Thrombectomy of Right Atrial Thrombus is Safe and Effective in Cancer Patients.OBJECTIVES: The aim of this study was to test the hypothesis that endovascular aspiration thrombectomy of right atrial thrombus (RAT) using the AngioVac device is as safe and effective in patients with cancer as those without cancer. BACKGROUND: RAT is a uniquely challenging clinical presentation of venous thromboembolism due to its low incidence and historically high-risk of mortality due to thrombus propagation into the pulmonary arteries. There is a lack of consensus regarding management, particularly in high-risk cancer patients. Endovascular aspiration thrombectomy utilizing the AngioVac device is effective in removal of right atrial thrombus and may be a safer option for patients with cancer in whom avoidance of higher-risk intervention is preferred. METHODS: This was an institutional review board-approved retrospective single-center case control study of patients with RAT who underwent AngioVac aspiration thrombectomy between August 2013 and July 2020. Analysis of patient demographics and clinical characteristics, thrombus-related factors, and operative details was performed. Primary endpoints included survival, safety, and technical success.
November 2021
Predictors of Heart Failure Symptoms in Hereditary Hemorrhagic Telangiectasia Patients with Hepatic Arteriovenous Malformations.BACKGROUND: Hepatic arteriovenous malformations (AVMs) in hereditary hemorrhagic telangiectasia (HHT) patients are most commonly hepatic artery to hepatic venous shunts which can result in high-output heart failure. This condition can be debilitating and is a leading cause of liver transplantation in HHT patients. However, it is not known what characteristics can discriminate between asymptomatic patients and those who will develop heart failure symptoms.
November 2021
The ECLIPSE Study: Efficacy of Cryoablation on Metastatic Lung Tumors With a 5-Year Follow-Up.INTRODUCTION: The ECLIPSE study aimed to evaluate the feasibility and efficacy of cryoablation (CA) for local tumor control in patients with pulmonary metastatic disease in 5 years of follow-up. METHODS: ECLIPSE was a prospective, multicenter, single-arm study that included patients treated with CA if they had one to five metastatic lung tumors, each with a diameter of less than or equal to 3.5 cm. Patients were followed up in the course of 5 years. The primary end point was local tumor control, both per tumor and per patient; secondary end points included cancer-specific survival, overall survival, and quality of life (QoL). QoL was evaluated using the Karnofsky Performance Score, the Eastern Cooperative Oncology Group performance score, and the Short Form-12 health survey.
November 2021
Spontaneous Portosystemic Shunt with Budd-Chiari Syndrome.A 62-year-old woman with a history of hepatic vein-type Budd-Chiari syndrome, which was treated with balloon angioplasty in 2013, presented with intermittent altered mental status for 2 months and was diagnosed with hepatic encephalopathy. An elevated serum ammonia level was found (105 µmol/L; reference range, 11-51 µmol/L)...
November 2021
ACR Appropriateness Criteria® Cerebrovascular Diseases-Aneurysm, Vascular Malformation, and Subarachnoid Hemorrhage.Cerebrovascular disease is a broad topic. This document focuses on the imaging recommendations for the varied clinical scenarios involving intracranial aneurysms, vascular malformations, and vasculitis, which all carry high risk of morbidity and mortality. Additional imaging recommendations regarding complications of these conditions, including subarachnoid hemorrhage and vasospasm, are also covered. While each variant presentation has unique imaging recommendations, the major focus of this document is neurovascular imaging techniques. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
November 2021
ACR Appropriateness Criteria® Noncerebral Vasculitis.Noncerebral vasculitis is a wide-range noninfectious inflammatory disorder affecting the vessels. Vasculitides have been categorized based on the vessel size, such as large-vessel vasculitis, medium-vessel vasculitis, and small-vessel vasculitis. In this document, we cover large-vessel vasculitis and medium-vessel vasculitis. Due to the challenges of vessel biopsy, imaging plays a crucial role in diagnosing this entity. While CTA and MRA can both provide anatomical details of the vessel wall, including wall thickness and enhancement in large-vessel vasculitis, FDG-PET/CT can show functional assessment based on the glycolytic activity of inflammatory cells in the inflamed vessels. Given the size of the vessel in medium-vessel vasculitis, invasive arteriography is still a choice for imaging. However, high-resolution CTA images can depict small-caliber aneurysms, and thus can be utilized in the diagnosis of medium-vessel vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
November 2021
Survival Advantage of Yttrium-90 Radioembolization to Systemic Therapy in Patients with Hepatic Metastases from Colorectal Cancer in the Salvage Setting: Results of a Matched Pair Study.RATIONALE AND OBJECTIVES: Patients with hepatic metastases from colorectal cancer have a poor prognosis in the salvage setting. This study assessed the survival benefit of adding transarterial 90Y radioembolization in the salvage setting to systemic therapy. MATERIALS AND METHODS: In this retrospective, matched-pair study, 21 patients who underwent radioembolization plus systemic therapy were matched with a cohort of 173 patients who received systemic chemotherapy alone in the salvage setting, defined as progression on at least two different regimens of systemic chemotherapy. Patients were matched one-to-one on Eastern Cooperative Oncology Group Performance Status, presence of extrahepatic disease, and presence of tumor KRAS mutation. Radioembolization patients underwent treatment using standard dosimetry to either a hepatic lobe or the whole liver. Survival data was analyzed using Kaplan-Meier analysis.
November 2021
Sodium MR Neuroimaging.Sodium MR imaging has the potential to complement routine proton MR imaging examinations with the goal of improving diagnosis, disease characterization, and clinical monitoring in neurologic diseases. In the past, the utility and exploration of sodium MR imaging as a valuable clinical tool have been limited due to the extremely low MR signal, but with recent improvements in imaging techniques and hardware, sodium MR imaging is on the verge of becoming clinically realistic for conditions that include brain tumors, ischemic stroke, and epilepsy. In this review, we briefly describe the fundamental physics of sodium MR imaging tailored to the neuroradiologist, focusing on the basics necessary to understand factors that play into making sodium MR imaging feasible for clinical settings and describing current controversies in the field. We will also discuss the current state of the field and the potential future clinical uses of sodium MR imaging in the diagnosis, phenotyping, and therapeutic monitoring in neurologic diseases.
November 2021
Cognitive Behavioral Therapy for Irritable Bowel Syndrome Induces Bidirectional Alterations in the Brain-gut-microbiome Axis Associated with Gastrointestinal Symptom Improvement.BACKGROUND: There is growing recognition that bidirectional signaling between the digestive tract and the brain contributes to irritable bowel syndrome (IBS). We recently showed in a large randomized controlled trial that cognitive behavioral therapy (CBT) reduces IBS symptom severity. This study investigated whether baseline brain and gut microbiome parameters predict CBT response and whether response is associated with changes in the brain-gut-microbiome (BGM) axis. METHODS: Eighty-four Rome III-diagnosed IBS patients receiving CBT were drawn from the Irritable Bowel Syndrome Outcome Study (IBSOS; ClinicalTrials.gov NCT00738920) for multimodal brain imaging and psychological assessments at baseline and after study completion. Fecal samples were collected at baseline and post-treatment from 34 CBT recipients for 16S rRNA gene sequencing, untargeted metabolomics, and measurement of short-chain fatty acids. Clinical measures, brain functional connectivity and microstructure, and microbiome features associated with CBT response were identified by multivariate linear and negative binomial models.
November 2021
Automated Identification and Assignment of Colonoscopy Surveillance Recommendations for Individuals with Colorectal Polyps.BACKGROUND AND AIMS: Determining surveillance intervals for patients with colorectal polyps is critical but time-consuming and challenging to do reliably. We present the development and assessment of a pipeline that leverages natural language processing techniques to automatically extract and analyze relevant polyp findings from free-text colonoscopy and pathology reports. Using this information, we categorized individual patients into 6 postcolonoscopy surveillance intervals defined by the U.S. Multi-Society Task Force on Colorectal Cancer. METHODS: Using a set of 546 randomly selected colonoscopy and pathology reports from 324 patients in a single health system, we used a combination of statistical classifiers and rule-based methods to extract polyp properties from each report type, associate properties with unique polyps, and classify a patient into 1 of 6 risk categories by integrating information from both report types. We then assessed the pipeline's performance by determining the positive predictive value (PPV), sensitivity, and F-score of the algorithm, compared with the determination of surveillance intervals by a gastroenterologist.
October 2021
Electrical Impedance Tomography for Non-invasive Identification of Fatty Liver Infiltrate in Overweight Individuals.Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of cardiometabolic diseases in overweight individuals. While liver biopsy is the current gold standard to diagnose NAFLD and magnetic resonance imaging (MRI) is a non-invasive alternative still under clinical trials, the former is invasive and the latter costly. We demonstrate electrical impedance tomography (EIT) as a portable method for detecting fatty infiltrate. We enrolled 19 overweight subjects to undergo liver MRI scans, followed by EIT measurements. The MRI images provided the a priori knowledge of the liver boundary conditions for EIT reconstruction, and the multi-echo MRI data quantified liver proton-density fat fraction (PDFF%) to validate fat infiltrate. Using the EIT electrode belts, we circumferentially injected pairwise current to the upper abdomen, followed by acquiring the resulting surface-voltage to reconstruct the liver conductivity. Pearson's correlation analyses compared EIT conductivity or MRI PDFF with body mass index, age, waist circumference, height, and weight variables. We reveal that the correlation between liver EIT conductivity or MRI PDFF with demographics is statistically insignificant, whereas liver EIT conductivity is inversely correlated with MRI PDFF (R = -0.69, p = 0.003, n = 16). As a pilot study, EIT conductivity provides a portable method for operator-independent and cost-effective detection of hepatic steatosis.
October 2021
Guided Tour of Hidden Tracts in the Pelvis: Exploring Pelvic Fistulas.BACKGROUND: Fistulas are an abnormal connection between two or more epithelial surfaces. When fistulization between adjacent structures occurs in the pelvis, there is almost invariably significant associated morbidity and impact on a patient's quality of life. Imaging may aid in the diagnosis of pelvic fistulas and is essential to identify any associated pathology, define the course of the fistula, and aid in pre-surgical planning. PURPOSE: This article aims to review the wide array of clinical and imaging presentations of fistulas in the pelvis, with a focus on the radiologists' role in managing this challenging entity. METHODS: This article will review each classification type of fistula.
October 2021
Safety of Irreversible Electroporation Ablation of the Pancreas.OBJECTIVES: To evaluate the safety of irreversible electroporation (IRE) on swine pancreatic tissue including its effects on peripancreatic vessels, bile ducts, and bowel. METHODS: Eighteen Yorkshire pigs underwent IRE ablation of the pancreas successfully and without clinical complications. Contrast-enhanced computed tomography angiography and laboratory studies before the IRE ablation with follow-up computed tomography angiography, laboratory testing, and pathological examination up to 4 weeks postablation were performed.
October 2021
Using a 3-Dimensional Printed Model to Plan Percutaneous Closure of an Unroofed Coronary Sinus.A 61-year-old man diagnosed with pulmonary arterial hypertension 5 years ago treated with tadalafil, atrial flutter status postablation, and multiple myeloma status post bone marrow transplantation 1 year prior presented for evaluation of exertional dyspnea. Physical examination revealed jugular venous distension and a mid-systolic murmur heard at the left upper sternal border without radiation.
October 2021
Scalable Quorum-based Deep Heural Networks with Adversarial Learning for Automated Lung Lobe Segmentation in Fast Helical Free-breathing CTs.PURPOSE: Fast helical free-breathing CT (FHFBCT) scans are widely used for 5DCT and 5D Cone Beam imaging protocols. For quantitative analysis of lung physiology and function, it is important to segment the lung lobes in these scans. Since the 5DCT protocols use up to 25 FHFBCT scans, it is important that this segmentation task be automated. In this paper, we present a deep neural network (DNN) framework for segmenting the lung lobes in near real time. METHODS: A total of 22 patient datasets (550 3D CT scans) were used for the study. Each of the lung lobes was manually segmented and considered ground-truth. A supervised and constrained generative adversarial network (CGAN) was employed for learning each set of lobe segmentations for each patient with 12 patients designated for training data. The resulting generator DNNs represented the lobe segmentations for each training dataset. A quorum-based algorithm was then implemented to test validation data consisting of 10 separate patient datasets (250 3D CTs). Each of the DNNs predicted their corresponding lobes for the validation data, and equal weights were given to the 12 generator CGANs. The quorum process worked by selecting the weighted average result of all 12 CGAN results for each lobe.
October 2021
Cancer-Associated Venous Thromboembolic Disease, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cancer-Associated Venous Thromboembolic Disease focus on the prevention, diagnosis, and treatment of patients with cancer who have developed or who are at risk for developing venous thromboembolism (VTE). VTE is a significant concern among cancer patients, who are at heightened risks for developing as well as dying from the disease. The management of patients with cancer with VTE often requires multidisciplinary efforts at treating institutions. The NCCN panel comprises specialists from various fields: cardiology, hematology/hematologic oncology, internal medicine, interventional radiology, medical oncology, pharmacology/pharmacy, and surgery/surgical oncology. This article focuses on VTE prophylaxis for medical and surgical oncology inpatients and outpatients, and discusses risk factors for VTE development, risk assessment tools, as well as management methods, including pharmacological and mechanical prophylactics. Contraindications to therapeutic interventions and special dosing, when required, are also discussed.
October 2021
Management of Clitoral Melanoma Presenting as an Exophytic Clitoral Mass: A Case Report and Review of the Literature.Primary mucosal melanomas of the female genital tract account for one percent or less of all cases of melanoma with even fewer originating in the clitoris. Given the rarity of diagnosis of clitoral melanoma, there is a paucity of data guiding management. There is no supporting evidence that radical vulvectomy (with or without inguinal lymphadenopathy) is associated with improved disease-free or overall survival compared to partial vulvectomy or wide local excision. Additionally, there is no data to evaluate the role of sentinel lymph node biopsy or extensive lymphadenectomy in clitoral melanoma, however previous evidence demonstrates the utility of regional lymph node sampling in predicting survival in women with female genital tract mucosal melanoma. Adjuvant therapy considerations are often extrapolated from their use in treating cutaneous melanomas, including immune checkpoint inhibitors and other immunotherapy agents. Adjuvant radiation therapy has limited utility except in cases of bulky, unresectable disease, or when inguinal lymph nodes are positive for metastasis. The 52 year-old patient presented in this review was diagnosed with locally invasive advanced stage clitoral melanoma presenting as an exophytic clitoral mass. She underwent diagnostic primary tumor resection, which demonstrated ulcerative melanoma with spindle cell features extending to a Breslow depth of at least 28 mm. She subsequently underwent secondary wide local excision with groin sentinel lymph node biopsy, and adjuvant treatment with pembrolizumab. This article also emphasizes the importance of a multidisciplinary team involving gynecologic oncology, medical oncology, radiology, and pathology for management of this rare type of primary mucosal melanoma of the female genital tract.
October 2021
Multimaterial Bioprinting and Combination of Processing Techniques Towards the Fabrication of Biomimetic Tissues and Organs.Tissue reconstruction requires the utilization of multiple biomaterials and cell types to replicate the delicate and complex structure of native tissues. Various three-dimensional (3D) bioprinting techniques have been developed to fabricate customized tissue structures; however, there are still significant challenges, such as vascularization, mechanical stability of printed constructs, and fabrication of gradient structures to be addressed for the creation of biomimetic and complex tissue constructs. One approach to address these challenges is to develop multimaterial 3D bioprinting techniques that can integrate various types of biomaterials and bioprinting capabilities towards the fabrication of more complex structures. Notable examples include multi-nozzle, coaxial, and microfluidics-assisted multimaterial 3D bioprinting techniques. More advanced multimaterial 3D printing techniques are emerging, and new areas in this niche technology are rapidly evolving. In this review, we briefly introduce the basics of individual 3D bioprinting techniques and then discuss the multimaterial 3D printing techniques that can be developed based on combination of these techniques for the engineering of complex and biomimetic tissue constructs. We also discuss the perspectives and future directions to develop state-of-the-art multimaterial 3D bioprinting techniques for engineering tissues and organs.
September 2021
Non-invasive Stereotactic Body Radiation Therapy for Refractory Ventricular Arrhythmias: an Institutional Experience.BACKGROUND: Initial studies have reported excellent safety and efficacy for stereotactic body radiation therapy (SBRT) in patients with refractory ventricular tachycardia (VT). METHODS: This is a single-center retrospective analysis of eight consecutive patients who underwent SBRT for refractory, scar-related VT. The anatomic target for radioablation was defined based on surface 12-lead ECG VT morphology, cardiac magnetic resonance imaging, and electroanatomic mapping data when available. The target volume treated and the prescribed radiation dose (15-25 Gy) was based on the combined clinical assessment of the cardiac electrophysiologist and radiation oncologist. Ventricular arrhythmias, radiation-related outcomes, and adverse events were monitored at follow-up.
September 2021
On-call Radiology 2020: Where Trainees Look for Help in a High Stakes and Time Sensitive Environment.BACKGROUND: The radiology trainee on-call experience has undergone many changes in the past decade. The development of numerous online information sources has changed the landscape of opportunities for trainees seeking information while on-call. In this study, we sought to understand the current on-call information seeking behaviors of radiology trainees. METHODS: We surveyed radiology fellows and residents at three major metropolitan area academic institutions. Survey topics included demographic information, on-call volumes, on-call resource seeking behaviors, preferred first and second line on-call resources and rationale for particular resource usage.
September 2021
Therapeutic Response Assessment of High-Grade Gliomas During Early-Phase Drug Development in the Era of Molecular and Immunotherapies.Several new therapeutic strategies have emerged over the past decades to address unmet clinical needs in high-grade gliomas, including targeted molecular agents and various forms of immunotherapy. Each of these strategies requires addressing fundamental questions, depending on the stage of drug development, including ensuring drug penetration into the brain, engagement of the drug with the desired target, biologic effects downstream from the target including metabolic and/or physiologic changes, and identifying evidence of clinical activity that could be expanded upon to increase the likelihood of a meaningful survival benefit. The current review article highlights these strategies and outlines how imaging technology can be used for therapeutic response evaluation in both targeted and immunotherapies in early phases of drug development in high-grade gliomas.
September 2021
TSI-GNN: Extending Graph Neural Networks to Handle Missing Data in Temporal Settings.We present a novel approach for imputing missing data that incorporates temporal information into bipartite graphs through an extension of graph representation learning. Missing data is abundant in several domains, particularly when observations are made over time. Most imputation methods make strong assumptions about the distribution of the data. While novel methods may relax some assumptions, they may not consider temporality. Moreover, when such methods are extended to handle time, they may not generalize without retraining. We propose using a joint bipartite graph approach to incorporate temporal sequence information. Specifically, the observation nodes and edges with temporal information are used in message passing to learn node and edge embeddings and to inform the imputation task. Our proposed method, temporal setting imputation using graph neural networks (TSI-GNN), captures sequence information that can then be used within an aggregation function of a graph neural network. To the best of our knowledge, this is the first effort to use a joint bipartite graph approach that captures sequence information to handle missing data. We use several benchmark datasets to test the performance of our method against a variety of conditions, comparing to both classic and contemporary methods. We further provide insight to manage the size of the generated TSI-GNN model. Through our analysis we show that incorporating temporal information into a bipartite graph improves the representation at the 30% and 60% missing rate, specifically when using a nonlinear model for downstream prediction tasks in regularly sampled datasets and is competitive with existing temporal methods under different scenarios.
September 2021
Prospective, Multicenter, Controlled Trial of Mobile Stroke Units.BACKGROUND: Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied. METHODS: In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.
September 2021
The Extent and Diverse Trajectories of Longitudinal Changes in Rheumatoid Arthritis Interstitial Lung Diseases Using Quantitative HRCT Scores.We aimed to validate quantitative high-resolution computed tomography (HRCT) imaging analyses of interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients, and to delineate a broad spectrum of annual longitudinal changes of ILD severity in the RA-ILD cohorts. Retrospective cohort 1 (n = 26) had matched PFT results and prospective cohort 2 (n = 34) were followed for over two years with baseline serum specimen. Automated quantitative analysis of HRCT was expressed as the extent of ground-glass opacity, lung fibrosis, honeycombing, and their summation-the total extent of quantitative ILD (QILD). Higher QILD score was associated with lower pulmonary function especially for DLCO% (ρ = -0.433, p = 0.027). Higher serum level of Krebs von den Lungen 6 were significantly associated with high QILD scores (ρ = 0.400, p = 0.026). Regarding QILD score changes in whole lung, even a single point increase was significantly associated with interval progression detected by the radiologist. Four distinct patterns (improvement, worsening, convex-like, and concave-like) during the 24 months were described by QILD scores. Prolonged disease duration of ILD at baseline was significantly associated with worsening of QILD scores. QILD has the potential to reliably evaluate the dynamic severity changes in patients with RA-ILD.
September 2021
Experiment Selection in Meta-Analytic Piecemeal Causal Discovery.Scientists try to design experiments that will yield maximal information. For instance, given the available evidence and a limitation on the number of variables that can be observed simultaneously, it may be more informative to intervene on variable X and observe the response of variable Y than to intervene on X and observe Z; in other situations, the opposite may be true. Scientists must often make these decisions without primary data. To address this problem, in previous work, we created software for annotating aggregate statistics in the literature and deriving consistent causal explanations, expressed as causal graphs. This meta-analytic pipeline is useful not only for synthesizing evidence but also for planning experiments: one can use it strategically to select experiments that could further eliminate causal graphs from consideration. In this paper, we introduce interpretable policies for selecting experiments in the context of piecemeal causal discovery, a common setting in biological sciences in which each experiment can measure not an entire system but rather a strict subset of its variables. The limits of this piecemeal approach are only beginning to be fully characterized, with crucial theoretical work published recently. With simulations, we show that our experiment-selection policies identify causal structures more efficiently than random experiment selection. Unlike methods that require primary data, our meta-analytic approach offers a flexible alternative for those seeking to incorporate qualitative domain knowledge into their search for causal mechanisms. We also present a method that categorizes hypotheses with respect to their utility for identifying a system's causal structure. Although this categorization is usually infeasible to perform manually, it is critical for conducting research efficiently.
September 2021
Managing Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee.The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.
September 2021
Sex-Dependent Cortical Volume Changes in Patients with Degenerative Cervical Myelopathy.Degenerative cervical myelopathy (DCM) is a progressive condition characterized by degeneration of osseocartilaginous structures within the cervical spine resulting in compression of the spinal cord and presentation of clinical symptoms. Compared to healthy controls (HCs), studies have shown DCM patients experience structural and functional reorganization in the brain; however, sex-dependent cortical differences in DCM patients remains largely unexplored. In the present study, we investigate the role of sex differences on the structure of the cerebral cortex in DCM and determine how structural differences may relate to clinical measures of neurological function. T1-weighted structural MRI scans were acquired in 85 symptomatic and asymptomatic patients with DCM and 90 age-matched HCs. Modified Japanese Orthopedic Association (mJOA) scores were obtained for patients. A general linear model was used to determine vertex-level significant differences in gray matter volume (GMV) between the following groups (1) male HCs and female HCs, (2) male patients and female patients, (3) male patients and male HCs, and (4) female patients and female HCs. Within patients, males exhibited larger GMV in motor, language, and vision related brain regions compared to female DCM patients. Males demonstrated a significant positive correlation between GMV and mJOA score, in which patients with worsening neurological symptoms exhibited decreasing GMV primarily across somatosensory and motor related cortical regions. Females exhibited a similar association, albeit across a broader range of cortical areas including those involved in pain processing. In sensorimotor regions, female patients consistently showed smaller GMV compared with male patients, independent of mJOA score. Results from the current study suggest strong sex-related differences in cortical volume in patients with DCM, which may reflect hormonal influence or differing compensation mechanisms.
September 2021
Should Tenecteplase be Given in Clinical Practice for Acute Ischemic Stroke Thrombolysis?Alteplase is the current evidence-based, regulatory approved, mainstay choice for intravenous thrombolysis in acute ischemic stroke (AIS), given as a bolus followed by a 1-hour infusion. Tenecteplase—a genetically modified variant of alteplase with regulatory approval for treatment of ST-segment-elevation myocardial infarction (STEMI) since 2000—has gained increasing interest as an alternative for alteplase over the past decade. This interest mostly arises from several favorable pharmacodynamic and pharmacokinetic properties of tenecteplase over alteplase that make it possible to achieve at least similar recanalization rates, give tenecteplase as a single bolus, and avoid some of the practical problems with alteplase.
September 2021
Minimizing Table time in Patients with Claustrophobia Using Focused Ferumoxytol-enhanced MR Angiography (f-FEMRA): a Feasibility Study.OBJECTIVES: To assess the feasibility of a rapid, focused ferumoxytol-enhanced MR angiography (f-FEMRA) protocol in patients with claustrophobia. METHODS: In this retrospective study, 13 patients with claustrophobia expressed reluctance to undergo conventional MR angiography, but agreed to a trial of up to 10 min in the scanner bore and underwent f-FEMRA. Thirteen matched control patients who underwent gadolinium-enhanced MR angiography (GEMRA) were identified for comparison of diagnostic image quality. For f-FEMRA, the time from localizer image acquisition to completion of the angiographic acquisition was measured. Two radiologists independently scored images on both f-FEMRA and GEMRA for arterial and venous image quality, motion artefact and diagnostic confidence using a 5-point scale, five being best. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the aorta and IVC were measured. The Wilcoxon rank-sum test, one-way ANOVA with Tukey correction and two-tailed t tests were utilized for statistical analyses.
September 2021
Worse Prognosis for IDH Wild-type Diffuse Gliomas with Larger Residual Biological Tumor Burden.OBJECTIVE: The association of overall survival (OS) with tumor burden, including contrast enhanced (CE) volume on CE T1-weighted images, fluid-attenuated inversion recovery (FLAIR) hyperintense volume, and 3, 4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (FDOPA) hypermetabolic volume, in isocitrate dehydrogenase (IDH) wild-type gliomas remains unclear. This study aimed to assess the association between biological tumor burden in pre- and post-operative status and OS in IDH wild-type gliomas, and evaluated which volume was the best predictor of OS. METHODS: Thirty-four patients with treatment-naïve IDH wild-type gliomas (WHO grade II 6, III 15, IV 13) were retrospectively included. Three pre-operative tumor regions of interest (ROIs) were segmented based on the CE, FLAIR hyperintense, and FDOPA hypermetabolic regions. Resected ROIs were segmented from the post-operative images. Residual CE, FLAIR hyperintense, and FDOPA hypermetabolic ROIs were created by subtracting resected ROIs from pre-operative ROIs. Cox regression analysis was conducted to investigate the association of OS with the volume of each ROI, and Akaike information criterion was used to assess the fitness.
September 2021
Engineering Elastic Sealants Based on Gelatin and Elastin-like Polypeptides for Endovascular Anastomosis.Cerebrovascular ischemia from intracranial atherosclerosis remains difficult to treat. Although current revascularization procedures, including intraluminal stents and extracranial to intracranial bypass, have shown some benefit, they suffer from perioperative and postoperative morbidity. To address these limitations, here we developed a novel approach that involves gluing of arteries and subsequent transmural anastomosis from the healthy donor into the ischemic recipient. This approach required an elastic vascular sealant with distinct mechanical properties and adhesion to facilitate anastomosis. We engineered two hydrogel-based glues: an elastic composite hydrogel based on methacryloyl elastin-like polypeptide (mELP) combined with gelatin methacryloyl (GelMA) and a stiff glue based on pure GelMA. Two formulations with distinct mechanical characteristics were necessary to achieve stable anastomosis. The elastic GelMA/mELP composite glue attained desirable mechanical properties (elastic modulus: 288 ± 19 kPa, extensibility: 34.5 ± 13.4%) and adhesion (shear strength: 26.7 ± 5.4 kPa) to the blood vessel, while the pure GelMA glue exhibited superior adhesion (shear strength: 49.4 ± 7.0 kPa) at the cost of increased stiffness (elastic modulus: 581 ± 51 kPa) and reduced extensibility (13.6 ± 2.5%). The in vitro biocompatibility tests confirmed that the glues were not cytotoxic and were biodegradable. In addition, an ex vivo porcine anastomosis model showed high arterial burst pressure resistance of 34.0 ± 7.5 kPa, which is well over normal (16 kPa), elevated (17.3 kPa), and hypertensive crisis (24 kPa) systolic blood pressures in humans. Finally, an in vivo swine model was used to assess the feasibility of using the newly developed two-glue system for an endovascular anastomosis. X-ray imaging confirmed that the anastomosis was made successfully without postoperative bleeding complications and the procedure was well tolerated. In the future, more studies are required to evaluate the performance of the developed sealants under various temperature and humidity ranges.
August 2021
An International, Multicenter Study of Intravenous Bevacizumab for Bleeding in Hereditary Hemorrhagic Telangiectasia: the InHIBIT-Bleed Study.Hereditary hemorrhagic telangiectasia (HHT, Osler-Weber-Rendu disease) is a rare multisystem vascular disorder causing chronic gastrointestinal bleeding, epistaxis, and severe anemia. Bevacizumab, an anti-vascular endothelial growth factor antibody, may be effective to treat bleeding in HHT. This international, multicenter, retrospective study evaluated the use of systemic bevacizumab to treat HHT-associated bleeding and anemia at 12 HHT treatment centers. Hemoglobin, epistaxis severity score, red cell units transfused, and intravenous iron infusions before and after treatment were evaluated using paired means testing and mixed-effects linear models. 238 HHT patients received bevacizumab for a median of 12 (range, 1-96) months. Compared with pretreatment, bevacizumab increased mean hemoglobin by 3.2 g/dL (95% CI, 2.9-3.5 g/dL) [mean hemoglobin 8.6 (8.5, 8.8) g/dL versus 11.8 (11.5, 12.1) g/dL, p.
August 2021
Retrieval of Bard Simon Nitinol Inferior Vena Cava Filters: Approaches, Technical Successes, Complications, and Clinical Outcomes.OBJECTIVE: The Simon Nitinol filter is a bi-level filtration device designed for permanent implantation that is no longer commercially available, but may result in similar complications to current commercially available long term indwelling temporary or permanent filters. Complications related to indwelling inferior vena cava filters include inferior vena cava thrombosis, inferior vena cava penetration, filter migration, and filter fracture. There is a paucity of reports describing the technical aspects related to retrieval of Simon Nitinol filters. MATERIALS AND METHODS: This study consisted of five patients with Simon Nitinol filters and describes the indication for retrieval, the retrieval techniques used to remove the filters, technical success, complications, and clinical course.
August 2021
Performance of Deep Learning and Genitourinary Radiologists in Detection of Prostate Cancer Using 3-T Multiparametric Magnetic Resonance Imaging.BACKGROUND: Several deep learning-based techniques have been developed for prostate cancer (PCa) detection using multiparametric magnetic resonance imaging (mpMRI), but few of them have been rigorously evaluated relative to radiologists' performance or whole-mount histopathology (WMHP). PURPOSE: To compare the performance of a previously proposed deep learning algorithm, FocalNet, and expert radiologists in the detection of PCa on mpMRI with WMHP as the reference. STUDY TYPE: Retrospective, single-center study. SUBJECTS: A total of 553 patients (development cohort: 427 patients; evaluation cohort: 126 patients) who underwent 3-T mpMRI prior to radical prostatectomy from October 2010 to February 2018. FIELD STRENGTH/SEQUENCE: 3-T, T2-weighted imaging and diffusion-weighted imaging. ASSESSMENT: FocalNet was trained on the development cohort to predict PCa locations by detection points, with a confidence value for each point, on the evaluation cohort. Four fellowship-trained genitourinary (GU) radiologists independently evaluated the evaluation cohort to detect suspicious PCa foci, annotate detection point locations, and assign a five-point suspicion score (1: least suspicious, 5: most suspicious) for each annotated detection point. The PCa detection performance of FocalNet and radiologists were evaluated by the lesion detection sensitivity vs. the number of false-positive detections at different thresholds on suspicion scores. Clinically significant lesions: Gleason Group (GG) ≥ 2 or pathological size ≥ 10 mm. Index lesions: the highest GG and the largest pathological size (secondary). STATISTICAL TESTS: Bootstrap hypothesis test for the detection sensitivity between radiologists and FocalNet.
August 2021
Catheter Directed Thrombolysis and Mechanical Intervention in Deep Venous Thrombosis: What is the Status After the ATTRACT Trial?Deep venous thrombosis (DVT) is a major cause of acute and chronic morbidity, mortality, and increased healthcare costs. Endovascular methods for thrombus removal and reestablishing venous patency are increasing in both scope and usage. The most commonly used method for endovascular thrombectomy is catheter-directed thrombolysis (CDT). Several studies have shown promise for CDT in alleviating acute symptomatology in acute lower extremity DVT as well as mitigating potential long-term consequences of DVT, such as post-thrombotic syndrome (PTS). The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial is the largest and most comprehensive randomized-controlled trial to date evaluating CDT compared to anticoagulation alone for the treatment of acute symptomatic proximal lower extremity DVT. This review discusses the current status of CDT and adjunctive endovascular interventions for DVT, particularly in the context of the ATTRACT trial.
August 2021
Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology.PURPOSE: To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung. MATERIALS AND METHODS: A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.
August 2021
Society of Interventional Radiology Quality Improvement Standards on Percutaneous Ablation of Non-Small Cell Lung Cancer and Metastatic Disease to the Lungs.PURPOSE: To provide guidance on quality improvement thresholds for outcomes and complications of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease. MATERIALS AND METHODS: A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Data were extracted from relevant studies and thresholds were derived from a calculation of 2 standard deviations from the weighted mean of each outcome. A modified Delphi technique was used to achieve consensus agreement on the thresholds.
August 2021
Notable Papers and New Directions in Sensors, Signals, and Imaging Informatics.OBJECTIVE: To identify and highlight research papers representing noteworthy developments in signals, sensors, and imaging informatics in 2020. METHOD: A broad literature search was conducted on PubMed and Scopus databases. We combined Medical Subject Heading (MeSH) terms and keywords to construct particular queries for sensors, signals, and image informatics. We only considered papers that have been published in journals providing at least three articles in the query response. Section editors then independently reviewed the titles and abstracts of preselected papers assessed on a three-point Likert scale. Papers were rated from 1 (do not include) to 3 (should be included) for each topical area (sensors, signals, and imaging informatics) and those with an average score of 2 or above were subsequently read and assessed again by two of the three co-editors. Finally, the top 14 papers with the highest combined scores were considered based on consensus.
August 2021
A Minority of Patients with Functional Seizures Have Abnormalities on Neuroimaging.OBJECTIVE: Functional seizures often are managed incorrectly as a diagnosis of exclusion. However, a significant minority of patients with functional seizures may have abnormalities on neuroimaging that typically are associated with epilepsy, leading to diagnostic confusion. We evaluated the rate of epilepsy-associated findings on MRI, FDG-PET, and CT in patients with functional seizures. METHODS: We studied radiologists' reports from neuroimages at our comprehensive epilepsy center from a consecutive series of patients diagnosed with functional seizures without comorbid epilepsy from 2006 to 2019. We summarized the MRI, FDG-PET, and CT results as follows: within normal limits, incidental findings, unrelated findings, non-specific abnormalities, post-operative study, epilepsy risk factors (ERF), borderline epilepsy-associated findings (EAF), and definitive EAF.
August 2021
Vorasidenib, a Dual Inhibitor of Mutant IDH1/2, in Recurrent or Progressive Glioma; Results of a First-in-Human Phase I Trial.PURPOSE: Lower grade gliomas (LGGs) are malignant brain tumors. Current therapy is associated with short- and long-term toxicity. Progression to higher tumor grade is associated with contrast enhancement on MRI. The majority of LGGs harbor mutations in the genes encoding isocitrate dehydrogenase 1 or 2 (IDH1/IDH2). Vorasidenib (AG-881) is a first-in-class, brain-penetrant, dual inhibitor of the mutant IDH1 and mutant IDH2 enzymes. PATIENTS AND METHODS: We conducted a multicenter, open-label, phase I, dose-escalation study of vorasidenib in 93 patients with mutant IDH1/2 (mIDH1/2) solid tumors, including 52 patients with glioma that had recurred or progressed following standard therapy. Vorasidenib was administered orally, once daily, in 28-day cycles until progression or unacceptable toxicity. Enrollment is complete; this trial is registered with ClinicalTrials.gov, NCT02481154.
August 2021
Association of Inclusion of More Black Individuals in Lung Cancer Screening With Reduced Mortality.IMPORTANCE: The potential to achieve greater reductions in lung cancer mortality than originally estimated by the National Lung Screening Trial with the inclusion of more Black participants stresses the importance of improving access to lung cancer screening for Black current and former smokers, a population presently with the highest lung cancer morbidity and mortality. OBJECTIVE: To estimate lung cancer and all-cause mortality reductions achievable with lung cancer screening via low-dose computed tomography (LDCT) of the chest in populations with greater proportions of Black screening participants than seen in the original NLST cohort. DESIGN, SETTING, AND PARTICIPANTS: This cohort study was conducted as a secondary analysis of existing data from the National Lung Screening Trial, a large national randomized clinical trial conducted from 2002 through 2009. NLST participants were current or former smokers, aged between 55 and 74 years, with at least 30 pack-years of smoking history and less than 15 years since quitting. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% CIs of lung cancer mortality and all-cause mortality according to LDCT screening compared with chest radiograph screening. Using a transportability formula, we estimated outcomes for LDCT screening among hypothetical populations by varying the distributions of Black individuals, women, and current smokers. Data were analyzed between September 2020 and March 2021. EXPOSURES: Lung screening with LDCT of the chest compared with chest radiography. MAIN OUTCOMES AND MEASURES: Lung cancer mortality and all-cause mortality.
August 2021
Sweet's Syndrome: A First in Human Lung Transplantation.Sweet's Syndrome (SS), also known as acute febrile neutrophilic dermatosis, is one of several cutaneous inflammatory disorders classified as neutrophilic dermatoses. Respiratory complications are described in <50 cases in the literature,1 without prior report of lung transplantation (LT). This article explains the clinical course of the first patient to receive LT for pulmonary SS and presents evidence suggesting recurrence of the primary lung disease in the allograft.
August 2021
History of Hepatic Encephalopathy Is Not a Contraindication to Transjugular Intrahepatic Portosystemic Shunt Placement for Refractory Ascites.INTRODUCTION: The outcomes of transjugular intrahepatic portosystemic shunt (TIPS) placement in patients with hepatic encephalopathy (HE) are controversial. We studied the relationship of pre-TIPS HE in patients undergoing TIPS for refractory ascites on all-cause mortality and development of post-TIPS HE. METHODS: A single-center retrospective comparison study was performed for patients undergoing TIPS for refractory ascites. Survival by history of pre-TIPS HE was demonstrated with Kaplan-Meier curves. Univariate and multivariate logistic regression analyses were performed to identify the predictors of post-TIPS clinical outcomes for patients with and without pre-TIPS HE.
August 2021
Disparities in Mortality and Health Care Utilization for 460,851 Hospitalized Patients with Cirrhosis and Hepatic Encephalopathy.BACKGROUND AND AIMS: Hepatic encephalopathy (HE) is a common cause of hospitalizations and readmissions for patients with decompensated cirrhosis. In this study, we proposed to investigate recent trends in in-hospital mortality and utilization for patients with cirrhosis and HE and to explore the effect of various sociodemographic, hospital, and clinical factors on mortality. METHODS: We performed an observational study using serial cross-sectional data from the 2009-2013 National Inpatient Sample to examine hospitalizations of patients with cirrhosis and HE. We collected data on in-hospital mortality, length of stay, and total hospital costs. We used negative binomial regression and logistic regression to investigate trends in utilization and multilevel modeling to examine the association between sociodemographic, hospital, and clinical factors and in-hospital mortality.
August 2021
A Physical Phantom for Amine Chemical Exchange Saturation Transfer (CEST) MRI.OBJECTIVE: To develop a robust amine chemical exchange saturation transfer (CEST) physical phantom, validate the temporal stability, and create a supporting software for automatic image processing and quality assurance. MATERIALS AND METHODS: The phantom was designed as an assembled laser-cut acrylic rack and 18 vials of phantom solutions, prepared with different pHs, glycine concentrations, and gadolinium concentrations. We evaluated glycine concentrations using ultraviolet absorbance for 70 days and measured the pH, relaxation rates, and CEST contrast for 94 days after preparation. We used Spearman's correlation to determine if glycine degraded over time. Linear regression and Bland-Altman analysis were performed between baseline and follow-up measurements of pH and MRI properties.
July 2021
Quantification of Tumor Microenvironment Acidity in Glioblastoma Using Principal Component Analysis of Dynamic Susceptibility Contrast Enhanced MR Imaging.Glioblastoma (GBM) has high metabolic demands, which can lead to acidification of the tumor microenvironment. We hypothesize that a machine learning model built on temporal principal component analysis (PCA) of dynamic susceptibility contrast-enhanced (DSC) perfusion MRI can be used to estimate tumor acidity in GBM, as estimated by pH-sensitive amine chemical exchange saturation transfer echo-planar imaging (CEST-EPI). We analyzed 78 MRI scans in 32 treatment naïve and post-treatment GBM patients. All patients were imaged with DSC-MRI, and pH-weighting that was quantified from CEST-EPI estimation of the magnetization transfer ratio asymmetry (MTRasym) at 3 ppm. Enhancing tumor (ET), non-enhancing core (NC), and peritumoral T2 hyperintensity (namely, edema, ED) were used to extract principal components (PCs) and to build support vector machines regression (SVR) models to predict MTRasym values using PCs. Our predicted map correlated with MTRasym values with Spearman's r equal to 0.66, 0.47, 0.67, 0.71, in NC, ET, ED, and overall, respectively (p < 0.006). The results of this study demonstrates that PCA analysis of DSC imaging data can provide information about tumor pH in GBM patients, with the strongest association within the peritumoral regions.
July 2021
Consensus Recommendations for MRI and PET Imaging of Primary Central Nervous System Lymphoma: Guideline Statement from the International Primary CNS Lymphoma Collaborative Group (IPCG).Advanced molecular and pathophysiologic characterization of primary central nervous system lymphoma (PCNSL) has revealed insights into promising targeted therapeutic approaches. Medical imaging plays a fundamental role in PCNSL diagnosis, staging, and response assessment. Institutional imaging variation and inconsistent clinical trial reporting diminishes the reliability and reproducibility of clinical response assessment. In this context, we aimed to: (1) critically review the use of advanced positron emission tomography (PET) and magnetic resonance imaging (MRI) in the setting of PCNSL; (2) provide results from an international survey of clinical sites describing the current practices for routine and advanced imaging, and (3) provide biologically based recommendations from the International PCNSL Collaborative Group (IPCG) on adaptation of standardized imaging practices. The IPCG provides PET and MRI consensus recommendations built upon previous recommendations for standardized brain tumor imaging protocols (BTIP) in primary and metastatic disease. A biologically integrated approach is provided to addresses the unique challenges associated with the imaging assessment of PCNSL. Detailed imaging parameters facilitate the adoption of these recommendations by researchers and clinicians. To enhance clinical feasibility, we have developed both "ideal" and "minimum standard" protocols at 3T and 1.5T MR systems that will facilitate widespread adoption.
July 2021
Extrapulmonary Sarcoidosis with a Focus on Cardiac, Nervous System, and Ocular Involvement.Sarcoidosis is a poorly understood granulomatous disease that involves the lungs and/or intrathoracic lymph nodes in more than 90% of cases. Although pulmonary sarcoidosis is the leading cause of mortality in this disease, this review focuses on three sites of extrapulmonary involvement (heart, nervous system, and eyes), since involvement of any of these sites can be catastrophic, leading to death, debilitation, or blindness. Patients with cardiac, ocular and neurosarcoidosis necessitate a multidisciplinary approach with careful and long-term follow-up. Prompt diagnosis with imaging and/or biopsy and treatment is required to avoid irreversible damage. Corticosteroids are the mainstay of therapy and are often associated with rapid and durable remissions. Immunosuppressive or biologic agents are reserved for patients failing or experiencing side effects from steroids. Managing sarcoidosis requires vigilance, judgement, and awareness of the vagaries of this fascinating disease.
July 2021
Ferumoxytol-enhanced Magnetic Resonance T1 Reactivity for Depiction of Myocardial Hypoperfusion.Myocardial T1 reactivity, defined as the relative change in T1 between rest and vasodilator-induced stress, has been proposed as a magnetic resonance imaging (MRI) biomarker of tissue perfusion. We hypothesize that the superparamagnetic iron-oxide nanoparticle, ferumoxytol, sensitizes T1 to changes in the intramyocardial vascular compartment and improves the sensitivity and specificity of T1 reactivity as an imaging biomarker of tissue perfusion. We aim to assess the diagnostic performance of ferumoxytol-enhanced (FE) myocardial T1 reactivity in swine models of myocardial hypoperfusion. We induced acute myocardial hypoperfusion in 13 swine via percutaneous, transcatheter deployment of a 3D printed intracoronary stenosis implant into the left anterior descending coronary artery. We performed native and FE adenosine stress testing using 5(3)3(3)3 MOLLI and SASHA T1 mapping sequences with bSSFP readout on a clinical 3.0 T magnet. MOLLI T1 maps were fitted using both the conventional MOLLI and the Instantaneous Signal Loss (InSiL) T1-fitting algorithms. Regardless of the MOLLI or SASHA pulse sequence or T1-fitting algorithm, ferumoxytol contrast increased the dynamic range of T1 reactivity in both the remote and ischemic myocardial regions. Relative to remote myocardium, native and FE T1 reactivity were blunted in ischemic myocardium (p < 0.05) with InSiL-MOLLI, MOLLI and SASHA. An InSiL-MOLLI-derived FE T1 reactivity threshold of -4.65% had 73.3% sensitivity and 96.2% specificity for prediction of regional wall motion abnormalities (AUC 0.915, 95% CI 0.786-0.979), whereas a SASHA-derived FE T1 reactivity threshold of -5.25% had 75.0% sensitivity and 95.2% specificity (AUC 0.905, 95% CI 0.751-0.979). Ferumoxytol significantly increased the dynamic range of T1 reactivity as a measure of myocardial hypoperfusion in vasodilator stress T1 mapping studies. FE T1 reactivity maps can be used to quantitatively distinguish ischemic and remote myocardium with high specificity in swine models of acute myocardial hypoperfusion.
July 2021
Modified RANO, Immunotherapy RANO, and Standard RANO Response to Convection-Enhanced Delivery of IL4R-Targeted Immunotoxin MDNA55 in Recurrent Glioblastoma.PURPOSE: The current study compared the standard response assessment in neuro-oncology (RANO), immunotherapy RANO (iRANO), and modified RANO (mRANO) criteria as well as quantified the association between progression-free (PFS) and overall survival (OS) in an immunotherapy trial in recurrent glioblastoma (rGBM). PATIENTS AND METHODS: A total of 47 patients with rGBM were enrolled in a prospective phase II convection-enhanced delivery of an IL4R-targeted immunotoxin (MDNA55-05, NCT02858895). Bidirectional tumor measurements were created by local sites and centrally by an independent radiologic faculty, then standard RANO, iRANO, and mRANO criteria were applied.
July 2021
Transarterial Chemoembolization of Hepatocellular Carcinoma with Oncozene Microspheres: An Initial, Short-Term Clinical Experience-A Retrospective, Matched, Comparison Study.BACKGROUND The purpose of this study is to describe a single institution's experience using Oncozene (OZ) microspheres for transarterial chemoembolization (OZ-TACE) of hepatocellular carcinoma (HCC), and to compare tolerability, safety, short-term radiographic tumor response, progression-free survival (PFS), and overall survival (OS) of these procedures to TACE (LC-TACE) performed with LC beads (LC). METHODS: A retrospective, matched cohort study of patients undergoing DEB-TACE (drug-eluting bead transarterial chemoembolization) with OZ or LC was performed. The cohort comprised 23 patients undergoing 29 TACE with 75 or 100 µm OZ and 24 patients undergoing 29 TACE with 100-300 µm LC. Outcome measures were changes in liver function tests, complications, treatment tolerability, short-term radiographic tumor response according to modified RECIST criteria for HCC, PFS, and 1-year OS. The Mann-Whitney U test, Fisher exact test, and log rank test were used to compare the groups
July 2021
A Simple Assessment of Lung Nodule Location for Reduction in Unnecessary Invasive Procedures.BACKGROUND: CT screening for lung cancer results in a significant mortality reduction but is complicated by invasive procedures performed for evaluation of the many detected benign nodules. The purpose of this study was to evaluate measures of nodule location within the lung as predictors of malignancy. METHODS: We analyzed images and data from 3,483 participants in the National Lung Screening Trial (NLST). All nodules (4-20 mm) were characterized by 3D geospatial location using a Cartesian coordinate system and evaluated in logistic regression analysis. Model development and probability cutpoint selection was performed in the NLST testing set. The Geospatial test was then validated in the NLST testing set, and subsequently replicated in a new cohort of 147 participants from The Detection of Early Lung Cancer Among Military Personnel (DECAMP) Consortium.
July 2021
COVID-19 and Breast Radiologist Wellness: Impact of Gender, Financial Loss, and Childcare Need.PURPOSE: The purpose of this study was to evaluate the emotional and financial impact of coronavirus disease 2019 (COVID-19) on breast radiologists to understand potential consequences on physician wellness and gender disparities in radiology. METHODS: A 41-question survey was distributed from June to September 2020 to members of the Society of Breast Imaging and the National Consortium of Breast Centers. Psychological distress and financial loss scores were calculated on the basis of survey responses and compared across gender and age subgroups. A multivariate logistic model was used to identify factors associated with psychological distress scores.
July 2021
Pulmonary Vein and Left Atrial Posterior Wall Isolation for the Treatment of Atrial Fibrillation: Comparable Outcomes for Adults with Congenital Heart Disease.INTRODUCTION: Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF). METHODS: A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period.
July 2021
Four-dimensional Multiphase Steady-State MRI with Ferumoxytol Enhancement: Early Multicenter Feasibility in Pediatric Congenital Heart Disease.BACKGROUND: The value of MRI in pediatric congenital heart disease (CHD) is well recognized; however, the requirement for expert oversight impedes its widespread use. Four-dimensional (4D) multiphase steady-state imaging with contrast enhancement (MUSIC) is a cardiovascular MRI technique that uses ferumoxytol and captures all anatomic features dynamically. PURPOSE: To evaluate multicenter feasibility of 4D MUSIC MRI in pediatric CHD. MATERIALS AND METHODS: In this prospective study, participants with CHD underwent 4D MUSIC MRI at 3.0 T or 1.5 T between 2014 and 2020. From a pool of 460 total studies, an equal number of MRI studies from three sites (n = 60) was chosen for detailed analysis. With use of a five-point scale, the feasibility of 4D MUSIC was scored on the basis of artifacts, image quality, and diagnostic confidence for intracardiac and vascular connections (n = 780). Respiratory motion suppression was assessed by using the signal intensity profile. Bias between 4D MUSIC and two-dimensional (2D) cine imaging was evaluated by using Bland-Altman analysis; 4D MUSIC examination duration was compared with that of the local standard for CHD.
July 2021
Comparison of Feeding-Artery-Only versus Nidus-Plus-Feeding-Artery Embolization of Pulmonary Arteriovenous Malformations.PURPOSE: To compare coil embolotherapy outcomes of feeding-artery-only versus nidus-plus-feeding-artery technique for treating pulmonary arteriovenous malformations (PAVMs). MATERIALS AND METHODS: A total of 219 treatment-naïve PAVMs embolized in 90 patients at a single center from 2008 to 2018 met inclusion criteria for retrospective evaluation. Of the patients, 87% had a diagnosis of hereditary hemorrhagic telangiectasia (HHT). Feeding artery (FA) diameters ≥2 mm were treated. Coil embolization techniques were classified on the basis of embolic deployment zone: (i) distal feeding artery (DFA) technique (coil-to-nidus distance ≤ 1 cm) or (ii) nidus plus feeding artery (NiFA) technique. Successful embolization predictors were assessed using a multivariate linear regression model with input from patient- and PAVM-specific variables.
July 2021
Frequency, Determinants, and Outcomes of Emboli to Distal and New Territories Related to Mechanical Thrombectomy for Acute Ischemic Stroke.BACKGROUND AND PURPOSE: Clot fragmentation and distal embolization during endovascular thrombectomy for acute ischemic stroke may produce emboli downstream of the target occlusion or in previously uninvolved territories. Susceptibility-weighted magnetic resonance imaging can identify both emboli to distal territories (EDT) and new territories (ENT) as new susceptibility vessel signs (SVS). Diffusion-weighted imaging (DWI) can identify infarcts in new territories (INT). METHODS: We studied consecutive acute ischemic stroke patients undergoing magnetic resonance imaging before and after thrombectomy. Frequency, predictors, and outcomes of EDT and ENT detected on gradient-recalled echo imaging (EDT-SVS and ENT-SVS) and INT detected on DWI (INT-DWI) were analyzed.
June 2021
Physical Examination and Ultrasound Evaluation of Patients with Superficial Venous Disease.Systematic and standardized evaluation of superficial venous disease, guided by knowledge of the various clinical presentations, venous anatomy, and pathophysiology of reflux, is essential for appropriate diagnosis and optimal treatment. Duplex ultrasonography is the standard for delineating venous anatomy, detecting anatomic variants, and identifying the origin of venous insufficiency. This article reviews tools and techniques essential for physical examination and ultrasound assessment of patients with superficial venous disease.
June 2021
Estimation of Fractional Myocardial Blood Volume and Water Exchange Using Ferumoxytol-enhanced Magnetic Resonance Imaging.Fractional myocardial blood volume (fMBV) estimated using ferumoxytol-enhanced magnetic resonance imaging (MRI) (FE-MRI) has the potential to capture a hemodynamic response to myocardial hypoperfusion during contrast steady state without reliance on gadolinium chelates. Ferumoxytol has a long intravascular half-life and its use for steady-state MRI is off-label. The aim of this prospective study was to optimize and evaluate a two-compartment model for estimation of fMBV based on FE-MRI. Nine healthy swine and one swine with artificially induced single-vessel coronary stenosis underwent MRI on a 3.0 T clinical magnet. Myocardial longitudinal spin-lattice relaxation rate (R1) was measured using the 5(3)3(3)3 modified Look-Locker inversion recovery (MOLLI) sequence before and at contrast steady state following seven ferumoxytol infusions (0.125-4.0 mg/kg). fMBV and water exchange were estimated using a two-compartment model. Model-fitted fMBV was compared to simple fast-exchange fMBV approximation and percent change in pre- and postferumoxytol R1. Dose undersampling schemes were investigated to reduce acquisition duration. Variation in fMBV was assessed using one-way analysis of variance. Fast-exchange fMBV and ferumoxytol dose undersampling were evaluated using Bland-Altman analysis. Healthy normal swine showed a mean mid-ventricular fMBV of 7.2 ± 1.4% and water exchange rate of 11.3 ± 5.1 s-1 . There was intersubject variation in fMBV (p < 0.05) without segmental variation (p = 0.387). fMBV derived from eight-dose and four-dose sampling schemes had no significant bias (mean difference = 0.07, p = 0.541, limits of agreement -1.04% [-1.45, -0.62%] to 1.18% [0.77, 1.59%]). Pixel-wise fMBV in one swine model with coronary artery stenosis showed elevated fMBV in ischemic segments (apical anterior: 11.90 ± 4.00%, apical septum: 16.10 ± 5.71%) relative to remote segments (apical inferior: 9.59 ± 3.35%, apical lateral: 9.38 ± 2.35%). A two-compartment model based on FE-MRI using the MOLLI sequence may enable estimation of fMBV in studies of ischemic heart disease. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 2.
June 2021
Cell-free DNA Methylation and Transcriptomic Signature Prediction of Pregnancies with Adverse Outcomes.Although analysis of maternal plasma cell-free content has been employed for screening of genetic abnormalities within a pregnancy, limited attention has been paid to its use for the detection of adverse pregnancy outcomes (APOs) based on placental function. Here we investigated cell-free DNA and RNA content of 102 maternal and 25 cord plasma samples. Employing a novel deconvolution methodology, we found that during the first trimester, placenta-specific DNA increased prior to the subsequent development of gestational diabetes with no change in patients with preeclampsia while decreasing with maternal obesity. Moreover, using cell-free RNA sequencing, APOs revealed 71 differentially expressed genes early in pregnancy. We noticed the upregulation of S100A8, MS4A3, and MMP8 that have been already associated with APOs but also the upregulation of BCL2L15 and the downregulation of ALPL that have never been associated with APOs. We constructed a classifier with a positive predictive ability (AUC) of 0.91 for APOs, 0.86 for preeclampsia alone and 0.64 for GDM. We conclude that placenta-specific cell-free nucleic acids during early gestation provide the possibility of predicting APOs prior to the emergence of characteristic clinical features.
June 2021
Giant Mediastinal Lymphocele after Esophagectomy Successfully Treated with Thoracic Duct Embolization.A 64-year old man had developed a giant mediastinal lymphocele after undergoing esophagectomy for the treatment of esophageal squamous cell carcinoma. The thoracic duct was embolized with six micro-coils, followed by embolization using a 1:3 mixture of N-butyl-2-cyanoacrylate (Histoacryl; B. Braun, Melsungen, Germany) and ethiodized oil. Resolution of the lymphocele was achieved within 5 days after embolization. To the best of our knowledge, ours is the first reported case of thoracic duct embolization for the treatment of mediastinal lymphocele.
June 2021
Reproducibility of Lung Nodule Radiomic Features: Multivariable and Univariable Investigations that Account for Interactions Between CT Acquisition and Reconstruction Parameters.PURPOSE: Recent studies have demonstrated a lack of reproducibility of radiomic features in response to variations in CT parameters. In addition, reproducibility of radiomic features has not been well established in clinical datasets. We aimed to investigate the effects of a wide range of CT acquisition and reconstruction parameters on radiomic features in a realistic setting using clinical low dose lung cancer screening cases. We performed univariable and multivariable explorations to consider the effects of individual parameters and the simultaneous interactions between three different acquisition/reconstruction parameters of radiation dose level, reconstructed slice thickness, and kernel. METHOD: A cohort of 89 lung cancer screening patients were collected that each had a solid lung nodule >4mm diameter. A computational pipeline was used to perform a simulation of dose reduction of the raw projection data, collected from patient scans. This was followed by reconstruction of raw data with weighted filter back projection (wFBP) algorithm and automatic lung nodule detection and segmentation using a computer-aided detection tool. For each patient, 36 different image datasets were created corresponding to dose levels of 100%, 50%, 25%, and 10% of the original dose level, three slice thicknesses of 0.6 mm, 1 mm, and 2 mm, as well as three reconstruction kernels of smooth, medium, and sharp. For each nodule, 226 well-known radiomic features were calculated at each image condition. The reproducibility of radiomic features was first evaluated by measuring the intercondition agreement of the feature values among the 36 image conditions. Then in a series of univariable analyses, the impact of individual CT parameters was assessed by selecting subsets of conditions with one varying and two constant CT parameters. In each subset, intraparameter agreements were assessed. Overall concordance correlation coefficient (OCCC) served as the measure of agreement. An OCCC ≥ 0.9 implied strong agreement and reproducibility of radiomic features in intercondition or intraparameter comparisons. Furthermore, the interaction of CT parameters in impacting radiomic feature values was investigated via ANOVA.
June 2021
Relative Oxygen Extraction Fraction (rOEF) MR Imaging Reveals Higher Hypoxia in Human Epidermal Growth Factor Receptor (EGFR) Amplified Compared with Non-amplified Gliomas.PURPOSE: Epidermal growth factor receptor (EGFR) amplification promotes gliomagenesis and is linked to lack of oxygen within the tumor microenvironment. Using hypoxia-sensitive spin-and-gradient echo echo-planar imaging and perfusion MRI, we investigated the influence of EGFR amplification on tissue oxygen availability and utilization in human gliomas. METHODS: This study included 72 histologically confirmed EGFR-amplified and non-amplified glioma patients. Reversible transverse relaxation rate (R2'), relative cerebral blood volume (rCBV), and relative oxygen extraction fraction (rOEF) were calculated for the contrast-enhancing and non-enhancing tumor regions. Using Student t test or Wilcoxon rank-sum test, median R2', rCBV, and rOEF were compared between EGFR-amplified and non-amplified gliomas. ROC analysis was performed to assess the ability of imaging characteristics to discriminate EGFR amplification status. Overall survival (OS) was determined using univariate and multivariate cox models. Kaplan-Meier survival curves were plotted and compared using the log-rank test.
June 2021
Novel Dual-Lumen Drainage Catheter to Enhance the Active Evacuation of Complex Fluid Collections.PURPOSE: To compare the performance of a dual-lumen flushable drainage catheter to a conventional catheter for complex fluid collection drainage. METHODS: Two prototype catheters (20- and 28-F) were created by incorporating a customized infusion lumen within the wall of a large-bore conventional drainage catheter, which facilitated simultaneous irrigation of the drainage lumen and the targeted collection via inward- and outward-facing infusion side holes. These were tested against unaltered 20- and 28-F conventional catheters to determine if the injection of a dedicated flush lumen improved rapidity and completeness of gravity drainage. In vitro models were created to simulate serous fluid, purulent/exudative fluid, particulate debris, and acute hematoma.
June 2021
Federated Learning Improves Site Performance in Multicenter Deep Learning Without Data Sharing.OBJECTIVE: To demonstrate enabling multi-institutional training without centralizing or sharing the underlying physical data via federated learning (FL). MATERIALS AND METHODS: Deep learning models were trained at each participating institution using local clinical data, and an additional model was trained using FL across all of the institutions.
June 2021
Caterpillar Mechanical Embolization Device: A New Vascular Plug.Vascular plugs are a popular and effective mechanical embolization device with several distinct advantages over other embolic devices including their superior control in high-flow vessels, precise deployability, and reduced procedure time because of their ability to achieve rapid occlusion.
June 2021
Outcomes with Multi-disciplinary Management of Central Lung Tumors with CT-guided Percutaneous High Dose Rate Brachyablation.BACKGROUND: Centrally located lung tumors present treatment challenges given their proximity to mediastinal structures including the central airway, esophagus, major vessels, and heart. Therapeutic options can be limited for medically inoperable patients, particularly if they have received previous thoracic radiotherapy. High dose rate (HDR) brachyablation was developed to improve the therapeutic ratio for patients with central lung tumors. The purpose of this study is to report initial safety and efficacy outcomes with this treatment for central lung malignancies. METHODS: From September 2015 to August 2019, a total of 25 patients with 37 pulmonary tumors were treated with percutaneous HDR brachyablation. Treatment was delivered by a multi-disciplinary team of interventional radiologists, pulmonologists, and radiation oncologists. Twenty-three patients received a median dose of 21.5 Gy (range 15-27.5) in a single fraction, whereas two patients received median dose of 24.75 Gy (range 24-25.5) over 2-3 fractions. Tumor local control (LC) was evaluated by Response Evaluation Criteria in Solid Tumors v1.1. Treatment-related toxicities were graded by Common Terminology Criteria for Adverse Events v5.0, with adverse events less than 90 days defined as acute, and those occurring later were defined as late. LC, progression-free survival (PFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method.
May 2021
Hepatobiliary Cancers, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.The NCCN Guidelines for Hepatobiliary Cancers focus on the screening, diagnosis, staging, treatment, and management of hepatocellular carcinoma (HCC), gallbladder cancer, and cancer of the bile ducts (intrahepatic and extrahepatic cholangiocarcinoma). Due to the multiple modalities that can be used to treat the disease and the complications that can arise from comorbid liver dysfunction, a multidisciplinary evaluation is essential for determining an optimal treatment strategy. A multidisciplinary team should include hepatologists, diagnostic radiologists, interventional radiologists, surgeons, medical oncologists, and pathologists with hepatobiliary cancer expertise. In addition to surgery, transplant, and intra-arterial therapies, there have been great advances in the systemic treatment of HCC. Until recently, sorafenib was the only systemic therapy option for patients with advanced HCC. In 2020, the combination of atezolizumab and bevacizumab became the first regimen to show superior survival to sorafenib, gaining it FDA approval as a new frontline standard regimen for unresectable or metastatic HCC. This article discusses the NCCN Guidelines recommendations for HCC.
May 2021
ACR Appropriateness Criteria® Syncope.Syncope and presyncope lead to well over one million emergency room visits in the United States each year. Elucidating the cause of syncope or presyncope, which are grouped together given similar etiologies and outcomes, can be exceedingly difficult given the diverse etiologies. This becomes more challenging as some causes, such as vasovagal syncope, are relatively innocuous while others, such as cardiac-related syncope, carry a significant increased risk of death. While the mainstay of syncope and presyncope assessment is a detailed history and physical examination, imaging can play a role in certain situations. In patients where a cardiovascular etiology is suspected based on the appropriate history, physical examination, and ECG findings, resting transthoracic echocardiography is usually considered appropriate for the initial imaging. While no imaging studies are considered usually appropriate when there is a low probability of cardiac or neurologic pathology, chest radiography may be appropriate in certain clinical situations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
May 2021
ACR Appropriateness Criteria® Head Trauma: 2021 Update.Head trauma (ie, head injury) is a significant public health concern and is a leading cause of morbidity and mortality in children and young adults. Neuroimaging plays an important role in the management of head and brain injury, which can be separated into acute (0-7 days), subacute (<3 months), then chronic (>3 months) phases. Over 75% of acute head trauma is classified as mild, of which over 75% have a normal Glasgow Coma Scale score of 15, therefore clinical practice guidelines universally recommend selective CT scanning in this patient population, which is often based on clinical decision rules. While CT is considered the first-line imaging modality for suspected intracranial injury, MRI is useful when there are persistent neurologic deficits that remain unexplained after CT, especially in the subacute or chronic phase. Regardless of time frame, head trauma with suspected vascular injury or suspected cerebrospinal fluid leak should also be evaluated with CT angiography or thin-section CT imaging of the skull base, respectively. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
May 2021
Accuracy and Safety of 1,055 Transjugular Liver Biopsies in Postliver Transplant Patients.INTRODUCTION: The purpose of this study was to investigate the rates of complications and diagnostic yield of transjugular liver biopsy (TJLB) in deceased donor liver transplant (DDLT) recipients. METHODS: From January 2009 to December 2019, 1,055 TJLBs were performed in 603 adult DDLT recipients with a mean age of 54 (±12 years). Data were retrospectively reviewed to determine the diagnostic efficacy and incidence of major and minor complications in the 3-day and 1-month period after TJLB. In addition, data were stratified according to platelet count and international normalized ratio to determine the safety of TJLB in patients with varying degrees of coagulopathy.
May 2021
Preservation of Posterior Tibial Artery Flow Following Dissection With Associated Aneurysmal Degeneration in Ehlers-Danlos Syndrome Type IV Treated With Flow-Diverting Stent.Ehlers-Danlos syndrome type IV (EDS-IV), the vascular type, is a rare genetic disorder affects the large and medium size arteries resulting in dissections, often with aneurysmal degeneration, intramural hematomas and pseudoaneurysms. Embolization or ligation is standard management for aneurysm formation. We present a case of an EDS-IV patient with a posterior tibial artery dissection with associated aneurysm successfully treated with Flow Diversion stent (FDS) preserving vessel patency and excluding the aneurysm. FDS technology allows for low profile, micro-catheter deliverable treatment options to exclude aneurysms in EDS-IV patients that are may be prone to spasm and dissection using more conventional stent graft technology.
May 2021
A Primer on RECIST 1.1 for Oncologic Imaging in Clinical Drug Trials.Drug discovery and approval in oncology is mediated by the use of imaging to evaluate drug efficacy in clinical trials. Imaging is performed while patients receive therapy to evaluate their response to treatment. Response criteria, specifically Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), are standardized and can be used at different time points to classify response into the categories of complete response, partial response, stable disease, or disease progression. At the trial level, categorical responses for all patients are summated into image-based trial endpoints. These outcome measures, including objective response rate (ORR) and progression-free survival (PFS), are characteristics that can be derived from imaging and can be used as surrogates for overall survival (OS). Similar to OS, ORR and PFS describe the efficacy of a drug. U.S. Food and Drug Administration (FDA) regulatory approval requires therapies to demonstrate direct evidence of clinical benefit, such as improved OS. However, multiple programs have been created to expedite drug approval for life-threatening illnesses, including advanced cancer. ORR and PFS have been accepted by the FDA as adequate predictors of OS on which to base drug approval decisions, thus substantially shortening the time and cost of drug development (1). Use of imaging surrogate markers for drug approval has become increasingly common, accounting for more than 90% of approvals through the Accelerated Approval Program and allowing for use of many therapies which have altered the course of cancer.
May 2021
Preferential Tumor Localization in Relation to 18F-FDOPA Uptake for Lower-grade Gliomas.PURPOSE: Although tumor localization and 3,4-dihydroxy-6-18F-fluoro-L-phenylalanine (FDOPA) uptake may have an association, preferential tumor localization in relation to FDOPA uptake is yet to be investigated in lower-grade gliomas (LGGs). This study aimed to identify differences in the frequency of tumor localization between FDOPA hypometabolic and hypermetabolic LGGs using a probabilistic radiographic atlas. METHODS: Fifty-one patients with newly diagnosed LGG (WHO grade II, 29; III, 22; isocitrate dehydrogenase wild-type, 21; mutant 1p19q non-codeleted,16; mutant codeleted, 14) who underwent FDOPA positron emission tomography (PET) were retrospectively selected. Semiautomated tumor segmentation on FLAIR was performed. Patients with LGGs were separated into two groups (FDOPA hypometabolic and hypermetabolic LGGs) according to the normalized maximum standardized uptake value of FDOPA PET (a threshold of the uptake in the striatum) within the segmented regions. Spatial normalization procedures to build a 3D MRI-based atlas using each segmented region were validated by an analysis of differential involvement statistical mapping.
May 2021
Cortical Morphometric Correlational Networks Associated with Cognitive Deficits in First Episode Schizophrenia.Schizophrenia (SCZ) is a chronic cognitive and behavioral disorder associated with abnormal cortical activity during information processing. Several brain structures associated with the seven performance domains evaluated using the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB) have shown cortical volume loss in first episode schizophrenia (FES) patients. However, the relationship between morphological organization and MCCB performance remains unclear. Therefore, in the current observational study, high-resolution structural MRI scans were collected from 50 FES patients, and the morphometric correlation network (MCN) using cortical volume was established to characterize the cortical pattern associated with poorer MCCB performance. We also investigated topological properties, such as the modularity, the degree and the betweenness centrality. Our findings show structural volume was directly and strongly associated with the cognitive deficits of FES patients in the precuneus, anterior cingulate, and fusiform gyrus, as well as the prefrontal, parietal, and sensorimotor cortices. The medial orbitofrontal, fusiform, and superior frontal gyri were not only identified as the predominant nodes with high degree and betweenness centrality in the MCN, but they were also found to be critical in performance in several of the MCCB domains. Together, these results suggest a widespread cortical network is altered in FES patients and that performance on the MCCB domains is associated with the core pathophysiology of SCZ.
May 2021
Image-Guided Percutaneous Thermal Ablation of Oligometastatic Ovarian and Non-Ovarian Gynecologic Tumors.PURPOSE: To assess the safety, feasibility, and efficacy of percutaneous thermal ablation (TA) in the treatment of metastatic gynecologic (GYN) tumors. MATERIALS AND METHODS: A study cohort of 42 consecutive women (mean age, 59. years; range, 25-78 years) with metastatic GYN tumors (119 metastatic tumors) treated with radiofrequency (n = 47 tumors), microwave (n = 47 tumors), or cryogenic (n = 30 tumors) ablation from over 2,800 ablations performed from January 2001 to January 2019 was identified. The primary GYN neoplasms consisted of ovarian (27 patients; 77 tumors; mean tumor diameter [MTD], 2.50 cm), uterine (7 patients; 26 tumors; MTD, 1.89 cm), endometrial (5 patients; 10 tumors; MTD, 2.8 cm), vaginal (2 patients; 5 tumors; MTD, 2.40 cm), and cervical (1 patient; 1 tumor; MTD, 1.90 cm) cancers. In order of descending frequency, metastatic tumors treated by TA were located in the liver or liver capsule (74%), lungs (13%), and peritoneal implants (9%). Single tumors were also treated in the kidneys, rectus muscle, perirectal soft tissue (2.5%), and retroperitoneal lymph nodes (1.6%). All efficacy parameters of TA and definitions of major and minor adverse events are categorized by the latest Society of Interventional Radiology reporting standards.
April 2021
Pelvic Floor Ultrasound: When, Why, and How?Pelvic floor disorders are a significant medical issue, reportedly affecting nearly one in four women in the United States. Nonetheless, until the last decade, there has been relatively limited imaging research into this highly prevalent disorder. The three major imaging modalities utilized to assess pelvic floor function are ultrasound, MRI and fluoroscopy. Pelvic floor ultrasound is a rapidly emerging technique which takes advantage of the widespread availability of ultrasound, the non-invasive and relatively inexpensive approach and the incorporation of real-time imaging and software advances which permit 3-D volume imaging. Pelvic floor ultrasound provides the opportunity to optimize patient counseling and enhance pre-operative planning by providing an anatomic and functional roadmap for the referring clinician. We recommend the consideration of pelvic floor ultrasound, as described here, as an addition to the imaging armamentarium available to physicians and surgeons serving this patient population.
April 2021
CT Evaluation of Unrepaired/incidental Congenital Cardiovascular Diseases in Adults.Congenital heart disease (CHD) affects approximately one million people in the USA with the number increasing by 5% each year. Patients are usually both diagnosed and treated in infancy, however many of them may have subclinical CHD that remains undiagnosed until late adulthood. Patients with complex CHD tend to be symptomatic and are diagnosed at a younger age than those with a single defect. CHDs can be divided into three categories, including cardiac, great vessels and coronary artery anomalies. Recent advances in computed tomography (CT) technology with faster acquisition time and improved spatial resolution allow for detailed evaluation of cardiac morphology and function. The concomitant increased utilization of CT has simultaneously led to more sensitive detection and more thorough diagnosis of CHD. Recognition of and understanding the imaging attributes specific to each anomaly is important for radiologists in order to make a correct and definite diagnosis. This article reviews the spectrum of CHDs, which persist into adulthood that may be encountered by radiologists on CT.
April 2021
Female Lower Urinary Tract Symptom Prevention and Treatment Strategies on Social Media: Mixed Correlation With Evidence.OBJECTIVE: To evaluate the level of evidence behind recommendations on social media for disease prevention in five lower urinary tract symptoms. MATERIALS & METHODS: We conducted a digital analysis of anonymous online posts on social media sites collected by a social media data mining service. One thousand posts about pelvic organ prolapse, stress urinary incontinence, overactive bladder, urinary tract infection, and interstitial cystitis/bladder pain syndrome were randomly selected. We analyzed these posts for recommendations regarding the prevention and treatment of these diseases, which were then compared to recommendations in available clinical guidelines and assessed for level of evidence.
April 2021
Minimizing Echo and Repetition Times in Magnetic Resonance Imaging Using a Double Half-echo k-space Acquisition and Low-rank Reconstruction.Sampling k-space asymmetrically (ie, partial Fourier sampling) in the readout direction is a common way to reduce the echo time (TE) during magnetic resonance image acquisitions. This technique requires overlap around the center of k-space to provide a calibration region for reconstruction, which limits the minimum fractional echo to ∿60% before artifacts are observed. The present study describes a method for reconstructing images from exact half echoes using two separate acquisitions with reversed readout polarity, effectively providing a full line of k-space without additional data around central k-space. This approach can benefit sequences or applications that prioritize short TE, short inter-echo spacing or short repetition time. An example of the latter is demonstrated to reduce banding artifacts in balanced steady-state free precession.
April 2021
Gut Wrenching: Cases of Missed Gastrointestinal Tumors and Their Mimics on Computed Tomography.Computed tomography (CT) of the abdomen and pelvis is one of the most common imaging studies ordered through the emergency department (ED). Because these studies are ordered for the detection of acute abnormalities and due to the relatively low incidence in patients presenting through the ED, gastrointestinal tumors are commonly missed. Moreover, many CT findings of malignant tumors overlap with benign entities, which can present a diagnostic challenge. This review article will describe the common CT findings of gastric, small bowel, colon, and appendiceal cancer as well as some of the common benign gastrointestinal conditions with similar imaging findings.
April 2021
The Emerging Role of Quantification of Imaging for Assessing the Severity and Disease Activity of Emphysema, Airway Disease, and Interstitial Lung Disease.There has been an explosion of use for quantitative image analysis in the setting of lung disease due to advances in acquisition protocols and postprocessing technology, including machine and deep learning. Despite the plethora of published papers, it is important to understand which approach has clinical validation and can be used in clinical practice. This paper provides an introduction to quantitative image analysis techniques being used in the investigation of lung disease and focusses on the techniques that have a reasonable clinical validation for being used in clinical trials and patient care.
April 2021
Guidelines for the Evaluation of Pulmonary Nodules Detected Incidentally or by Screening: A Survey of Radiologist Awareness, Agreement, and Adherence From the Watch the Spot Trial.PURPOSE: The aim of this study was to examine radiologists' beliefs about existing guidelines for pulmonary nodule evaluation. METHODS: A self-administered survey was developed to ascertain awareness of, agreement with, and adherence to published guidelines, including those from the Fleischner Society and the Lung CT Screening Reporting and Data System (Lung-RADS™). Surveys were distributed to 514 radiologists at 13 health care systems that are participating in a large, pragmatic trial of pulmonary nodule evaluation. Prespecified comparisons were made among groups defined by type of health system, years of experience, reader volume, and study arm.
April 2021
Percutaneous Intrauterine Device Placement: A Solution for Hematometra Due to Cervicovaginal Agenesis.Möllerian duct underdevelopment results in agenesis and atresia of the vagina,cervix, or uterus, which can lead to hematometra and hematometrocolpos.Management includes vaginal-cervical serial dilation and/or surgery andmenstrual suppression with endovaginallevonorgestrel intrauterine device(IUD) placement. However, these options are not feasible in vaginal agenesisbecause there is no external tract. This report describes the percutaneousplacement of an IUD to treat hematometra due to cervicovaginal agenesis.
April 2021
Trans-Synaptic Degeneration of the Optic Radiation from Optic Nerve Atrophy.Fourty-seven-year-old woman with 5-year history of progressive decreased left eye vision. Optical coherence tomography showed optic nerve atrophy (left > right) and brain MRI revealed T2 hyperintense signal along the course of left optic radiations. We present a case of a trans-synaptic degeneration of the optic radiation in a patient with confirmed optic atrophy. Trans-synaptic degeneration of the optic radiation without associated infarct or inflammatory disease has not been reported before in patients with optic atrophy.
April 2021
Endovascular Removal of Thrombus and Right Heart Masses Using the AngioVac System: Results of 234 Patients from the Prospective, Multicenter Registry of AngioVac Procedures in Detail (RAPID).PURPOSE: To assess device and procedural safety and technical success associated with the use of the AngioVac System to remove vascular thrombi and cardiac masses. MATERIALS & METHODS: The Registry of AngioVac Procedures in Detail (RAPID) study prospectively collected data for 234 patients receiving treatment with AngioVac at 21 sites between March 2016 and August 2019: 84 (35.9%) with caval thromboemboli (CTEs), 113 (48.3%) with right heart masses (RHMs), 20 (8.5%) with catheter-related thrombi (CRTs), and 4 (1.7%) with pulmonary emboli (PEs). Thirteen patients had a combination of procedures during the same admission.
April 2021
Gastroenterology Visitation and Reminders Predict Surveillance Uptake for Patients with adenomas with High-risk Features.Individuals diagnosed with colorectal adenomas with high-risk features during screening colonoscopy have increased risk for the development of subsequent adenomas and colorectal cancer. While US guidelines recommend surveillance colonoscopy at 3 years in this high-risk population, surveillance uptake is suboptimal. To inform future interventions to improve surveillance uptake, we sought to assess surveillance rates and identify facilitators of uptake in a large integrated health system. We utilized a cohort of patients with a diagnosis of ≥ 1 tubular adenoma (TA) with high-risk features (TA ≥ 1 cm, TA with villous features, TA with high-grade dysplasia, or ≥ 3 TA of any size) on colonoscopy between 2013 and 2016. Surveillance colonoscopy completion within 3.5 years of diagnosis of an adenoma with high-risk features was our primary outcome. We evaluated surveillance uptake over time and utilized logistic regression to detect factors associated with completion of surveillance colonoscopy. The final cohort was comprised of 405 patients. 172 (42.5%) patients successfully completed surveillance colonoscopy by 3.5 years.
April 2021
Role of Intravenous Tissue Plasminogen Activator in Acute Ischemic Stroke with Large Vessel Occlusion.OBJECTIVE: The goal of the present study was to determine the safety and efficacy of intravenous tissue plasminogen activator (IVT) in patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO) undergoing mechanical thrombectomy (MT). METHODS: We performed a retrospective analysis of prospectively collected data gathered during a 3-year period for all our patients with AIS and LVO. We analyzed the stroke outcomes and complications between patients who had received a combination of IVT and MT and those who had undergone MT only. Standardized selection criteria, including the uniform use of perfusion imaging, were used for selection for MT, irrespective of IVT administration.
April 2021
Dynamic Fluoroscopic Defecography: Updates on Rationale, Technique, and Interpretation from the Society of Abdominal Radiology Pelvic Floor Disease Focus Panel.Whether used as the primary diagnostic test or reserved as a problem-solving examination, fluoroscopic defecography (FD) remains an important tool in the workup and treatment of defecatory disorders. FD is a well-established, simple, and rapid examination that most closely resembles the actual process and position that a patient uses to enable defecation and provides both qualitative and quantitative information on the defecatory process. FD is indicated when re-creating the act of defecation is necessary, especially in patients with symptoms of obstructed defecation and where symptoms do not correlate with prior examinations such as MRI. Also, FD may help the patient understand the severity of their condition, better informing them of the structural and functional pathology, and aid in discussions with the surgeon regarding plans for treating their complex pelvic floor and defecatory problems. This review provides an up-to-date, comprehensive summary of FD and describes the indications for, techniques of, and common pathology encountered.
April 2021
How to Develop and Sustain a Successful Pelvic Floor MRI Practice.PURPOSE: Magnetic resonance imaging (MRI) of the pelvic floor has become a commonly requested diagnostic tool for pelvic floor assessment. We provide a practical guide for developing, growing, and troubleshooting a dedicated pelvic floor imaging service. METHODS: The authors provide an organized approach to the development of a pelvic floor MRI program based on the experience of the SAR Pelvic Floor Disease Focused Panel in academic and private practice settings. Topics addressed include creating interest, staff education, patient preparation both before and after arrival to the imaging center, image acquisition, reporting, and troubleshooting.
March 2021
Focal Laser Ablation of Prostate Cancer: An Office Procedure.In this article, we describe and illustrate an outpatient procedure for focal laser ablation (FLA) of prostate cancer (PCa). The procedure is conceptually similar to a fusion biopsy and is performed under local anesthesia in a clinic setting; treatment time is usually less than one hour. Laser insertion is guided by ultrasound; lesion targeting is via magnetic resonance imaging-ultrasound (MRI/US) fusion, as in targeted prostate biopsy. Real-time ablation monitoring is achieved utilizing a thermal probe adjacent to the laser fiber. The video demonstrates procedure planning, patient preparation, various steps during the procedure, and treatment monitoring. Safety, feasibility, and efficacy of this approach have been established during a previous trial. Outpatient FLA under local anesthesia is an option for management of intermediate risk prostate cancer.
March 2021
Denosumab Treatment for Giant Cell Tumor of the Spine Including the Sacrum.STUDY DESIGN: This was a subanalysis of an international, multicenter, open-label study. OBJECTIVE: The aim of this study was to assess the efficacy and safety of denosumab in a subset of patients with giant cell tumors of bone (GCTB) of the spine including the sacrum from an international, open-label, single-arm, phase 2 study (ClinicalTrials.gov: NCT00680992). SUMMARY OF BACKGROUND DATA: Standard GCTB treatment is surgical removal, either by curettage or resection, combined with intraoperative adjuvant therapy; however, some sites may not be amenable to resection (e.g., skull, spine). METHODS: Adults or skeletally mature adolescents with pathologically confirmed GCTB of the spine including the sacrum, and radiologically measurable evidence of active disease, were included. Patients received denosumab (120 mg subcutaneously) once every 4 weeks during the treatment phase, with loading doses on days 8 and 15 of the first cycle. Patients had surgically unsalvageable GCTB (Cohort 1), had planned surgery expected to result in severe morbidity (Cohort 2), or were enrolled from a previous GCTB study (Cohort 3).
March 2021
Concomitant AngioVac Thrombectomy and Patent Foramen Ovale Closure in a Patient with a Large Right Atrial Thrombus and Recent Paradoxical Embolic Stroke.A 59-year-old male with a history of gallbladder adenocarcinoma receiving chemotherapy and on therapeutic anticoagulation for portal vein thrombosis presented to the emergency department via ambulance after being found unresponsive and in cardiac arrest. Initial workup upon return of spontaneous circulation revealed a large right atrial mass, patent foramen ovale (PFO), and bilateral acute cortical infarctions. This constellation of findings were concerning for PFO-related paradoxical embolic strokes. Given the risk of recurrent paradoxical embolic events and the absolute contraindication to thrombolysis due to recent cerebral infarction, the decision was made to proceed with percutaneous vacuum-assisted thrombectomy using the AngioVac device. To prevent intraoperative thrombus propagation, PFO-closure was performed immediately prior to thrombectomy. Aspiration thrombectomy and PFO-closure were successful with complete thrombus removal and no intraoperative thrombus propagation. This case presents a minimally invasive and rapid treatment for a complex problem. An efficient and effective interdisciplinary team-based approach allowed the patient to resume cancer treatment relatively unabated.
March 2021
Unique Challenges for Glioblastoma Immunotherapy-discussions Across Neuro-Oncology and Non-neuro-oncology Experts in Cancer Immunology. Meeting Report from the 2019 SNO Immuno-Oncology Think Tank.Cancer immunotherapy has made remarkable advances with over 50 separate Food and Drug Administration (FDA) approvals as first- or second-line indications since 2015. These include immune checkpoint blocking antibodies, chimeric antigen receptor-transduced T cells, and bispecific T-cell-engaging antibodies. While multiple cancer types now benefit from these immunotherapies, notable exceptions thus far include brain tumors, such as glioblastoma. As such, it seems critical to gain a better understanding of unique mechanistic challenges underlying the resistance of malignant gliomas to immunotherapy, as well as to acquire insights into the development of future strategies. An Immuno-Oncology Think Tank Meeting was held during the 2019 Annual Society for Neuro-Oncology Scientific Conference. Discussants in the fields of neuro-oncology, neurosurgery, neuro-imaging, medical oncology, and cancer immunology participated in the meeting. Sessions focused on topics such as the tumor microenvironment, myeloid cells, T-cell dysfunction, cellular engineering, and translational aspects that are critical and unique challenges inherent with primary brain tumors. In this review, we summarize the discussions and the key messages from the meeting, which may potentially serve as a basis for advancing the field of immune neuro-oncology in a collaborative manner.
March 2021
Society of Interventional Radiology Quality Improvement Standards for Percutaneous Transcatheter Embolization.Percutaneous embolization procedures are commonly performed by interventional radiologists. This quality improvement (QI) standard was first published in 2010 (1), and this document represents the second update. Since the 2010 standards, many additional randomized controlled trials, meta-analyses, and observational studies have been published on transcatheter embolization for various disease entities, further establishing embolization as an effective treatment. Additionally, the indications of embolization have expanded with newer procedures, like prostatic embolization for benign prostatic hyperplasia (BPH), and emerging procedures, such as left gastric artery embolization for the treatment of obesity and genicular artery embolization for the treatment of pain related to osteoarthritis (OA). This revised document includes a discussion on the performance of embolization procedures in pediatric patients, emphasizes the current literature, and builds upon previous documents to provide up-to-date information to ensure effective, safe, and high-quality care.
March 2021
Cryoablation for Palliation of Painful Bone Metastases: The MOTION Multicenter Study.PURPOSE: To assess the clinical effectiveness of cryoablation for palliation of painful bone metastases. MATERIALS & METHODS: MOTION (Multicenter Study of Cryoablation for Palliation of Painful Bone Metastases) (ClinicalTrials.gov NCT02511678) was a multicenter, prospective, single-arm study of adults with metastatic bone disease who were not candidates for or had not benefited from standard therapy, that took place from February 2016 to March 2018. At baseline, participants rated their pain using the Brief Pain Inventory-Short Form (reference range from 0 to 10 points); those with moderate to severe pain, who had at least one metastatic candidate tumor for ablation, were included. The primary effectiveness endpoint was change in pain score from baseline to week 8. Participants were followed for 24 weeks after treatment. Statistical analyses included descriptive statistics and logistic regression to evaluate changes in pain score over the postprocedure follow-up period.
March 2021
Prospect of Artificial Intelligence for the Assessment of Cardiac Function and Treatment of Cardiovascular Disease.During the past decade, artificial intelligence (AI) has become sufficiently advanced to begin impacting many aspects of the human life. Applications of AI in medicine have currently been limited to the gears that facilitate physicians' tasks and improve their clinical workflow. In cardiovascular medicine, AI has been integrated into software that facilitate data analysis used in research and development, diagnostic imaging and population health.
March 2021
Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer.PURPOSE: Magnetic resonance imaging-guided transurethral ultrasound ablation uses directional thermal ultrasound under magnetic resonance imaging thermometry feedback control for prostatic ablation. We report 12-month outcomes from a prospective multicenter trial (TACT). MATERIALS AND METHODS: A total of 115 men with favorable to intermediate risk prostate cancer across 13 centers were treated with whole gland ablation sparing the urethra and apical sphincter. The co-primary 12-month endpoints were safety and efficacy.
March 2021
Image-Guided Biopsies and Interventions of Mediastinal Lesions.Optimal assessment of the mediastinal masses is performed by a combination of clinical, radiological and often histological assessments. Image-guided transthoracic biopsy of mediastinal lesions is a minimally invasive and reliable procedure to obtain tissue samples, establish a diagnosis and provide a treatment plan. Biopsy can be performed under Computed Tomography, MRI, or ultrasound guidance, using a fine needle aspiration or a core-needle. In this paper, we review the image-guided strategies and techniques for histologic sampling of mediastinal lesions, along with the related clinical scenarios and possible procedural complications. In addition, image-guided mediastinal drainage and mediastinal ablations will be briefly discussed.
March 2021
Latent Traits of Lung Tissue Patterns in Former Smokers Derived by Dual Channel Deep Learning in Computed Tomography Images.Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease and the traditional variables extracted from computed tomography (CT) images may not be sufficient to describe all the topological features of lung tissues in COPD patients. We employed an unsupervised three-dimensional (3D) convolutional autoencoder (CAE)-feature constructor (FC) deep learning network to learn from CT data and derive tissue pattern-clusters jointly. We then applied exploratory factor analysis (EFA) to discover the unobserved latent traits (factors) among pattern-clusters. CT images at total lung capacity (TLC) and residual volume (RV) of 541 former smokers and 59 healthy non-smokers from the cohort of the SubPopulations and Intermediate Outcome Measures in the COPD Study (SPIROMICS) were analyzed. TLC and RV images were registered to calculate the Jacobian (determinant) values for all the voxels in TLC images. 3D Regions of interest (ROIs) with two data channels of CT intensity and Jacobian value were randomly extracted from training images and were fed to the 3D CAE-FC model.
March 2021
The Role of PSMA PET/CT and PET/MRI in the Initial Staging of Prostate Cancer.CONTEXT: Prostate cancer (PCa) is the most common solid organ malignancy in men and is the third leading cause of cancer death. Accurate methods for the detection and staging of PCa are necessary to determine the extent of disease and inform treatment options. OBJECTIVE: To review the performance and diagnostic accuracy of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging in the initial staging of PCa and evaluate its impact on definitive therapy planning. EVIDENCE ACQUISITION: A comprehensive literature search was performed using PubMed. References from retrieved articles and recommendations from the authors were also included.
March 2021
Rapid Measurement of the Low Contrast Detectability of CT Scanners.PURPOSE: Low contrast detectability (LCD) is a metric of fundamental importance in computed tomography (CT) imaging. In spite of this, its measurement is challenging in the context of nonlinear data processing. We introduce a new framework for objectively characterizing LCD with a single scan of a special-purpose phantom and automated analysis software. The output of the analysis software is a "machine LCD" metric which is more representative of LCD than contrast-noise ratio (CNR). It is not intended to replace human observer or model observer studies. METHODS: Following preliminary simulations, we fabricated a phantom containing hundreds of low-contrast beads. These beads are acrylic spheres (1.6 mm, net contrast ~10 HU) suspended and randomly dispersed in a background matrix of nylon pellets and isoattenuating saline. The task was to search for and localize the beads. A modified matched filter was used to automatically scan the reconstruction and select candidate bead localizations of varying confidence. These were compared to bead locations as determined from a high-dose reference scan to produce free-response ROC curves. We compared iterative reconstruction (IR) and filtered backpropagation (FBP) at multiple dose levels between 40 and 240 mAs. The scans at 60, 120, and 180 mAs were performed three times each to estimate uncertainty.
March 2021
Birt-Hogg-Dubé Syndrome Presenting with Chronic Progressive Dyspnea.Birt-Hogg-Dubé Syndrome (BHDS) is a rare autosomal dominant disease which manifests with cutaneous hamartomas, lung cysts and renal carcinomas. A wide spectrum of phenotypic expression and few visible manifestations makes BHDS a likely under-recognized entity. Diffuse cystic lung disease (DCLD) is the typical pulmonary manifestation of BHDS, which in the absence of other specific findings carries a broad differential diagnosis. Unlike many other causes of DCLD, BHDS is not known to present with symptomatic pulmonary dysfunction. We report a typical case of BHDS with an atypical presentation - chronic progressive dyspnea. The unusual presentation provides an opportunity to discuss the differential for DCLD and highlights the importance of maintaining an index of suspicion for BHDS even when symptoms appear inconsistent with the diagnosis. Also examined is the management of BHDS patients and their immediate relatives, and recommendations for the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) given the potential risk of pneumothorax in this group.
March 2021
A Framework for Sharing Radiation Dose Distribution Maps in the Electronic Medical Record for Improving Multidisciplinary Patient Management.Radiation oncology practices use a suite of dedicated software and hardware that are not common to other medical subspecialties, making radiation treatment history inaccessible to colleagues. A radiation dose distribution map is generated for each patient internally that allows for visualization of the dose given to each anatomic structure volumetrically; however, this crucial information is not shared systematically to multidisciplinary medical, surgery, and radiology colleagues. A framework was developed in which dose distribution volumes are uploaded onto the medical center's picture archiving and communication system (PACS) to rapidly retrieve and review exactly where, when, and to what dose a lesion or structure was treated. The ability to easily visualize radiation therapy information allows radiology clinics to incorporate radiation dose into image interpretation without direct access to radiation oncology planning software and data. Tumor board discussions are simplified by incorporating radiation therapy information collectively in real time, and daily onboard imaging can also be uploaded while a patient is still undergoing radiation therapy. Placing dose distribution information into PACS facilitates central access into the electronic medical record and provides a succinct visual summary of a patient's radiation history for all medical providers. More broadly, the radiation dose map provides greater visibility and facilitates incorporation of a patient's radiation history to improve oncologic decision making and patient outcomes.
March 2021
68Ga-FAPi-46 Diffuse Bilateral Breast Uptake in a Patient with Cervical Cancer After Hormonal Stimulation.A 36-year-old female patient diagnosed with invasive squamous cell carcinoma of the cervix underwent an 18F-fluorodeoxyglucose ([18F]FDG) PET/CT scan for presurgical staging.
March 2021
Differentiating IDH Status in Human Gliomas Using Machine Learning and Multiparametric MR/PET.BACKGROUND: The purpose of this study was to develop a voxel-wise clustering method of multiparametric magnetic resonance imaging (MRI) and 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (FDOPA) positron emission tomography (PET) images using an unsupervised, two-level clustering approach followed by support vector machine in order to classify the isocitrate dehydrogenase (IDH) status of gliomas. METHODS: Sixty-two treatment-naïve glioma patients who underwent FDOPA PET and MRI were retrospectively included. Contrast enhanced T1-weighted images, T2-weighted images, fluid-attenuated inversion recovery images, apparent diffusion coefficient maps, and relative cerebral blood volume maps, and FDOPA PET images were used for voxel-wise feature extraction. An unsupervised two-level clustering approach, including a self-organizing map followed by the K-means algorithm was used, and each class label was applied to the original images. The logarithmic ratio of labels in each class within tumor regions was applied to a support vector machine to differentiate IDH mutation status. The area under the curve (AUC) of receiver operating characteristic curves, accuracy, and F1-socore were calculated and used as metrics for performance.
March 2021
Voxelwise and Patientwise Correlation of 18F-FDOPA PET, Relative Cerebral Blood Volume, and Apparent Diffusion Coefficient in Treatment-Naïve Diffuse Gliomas with Different Molecular Subtypes.Our purpose was to identify correlations between 18F-fluorodihydroxyphenylalanine (18F-FDOPA) uptake and physiologic MRI, including relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC), in gliomas with different molecular subtypes and to evaluate their prognostic values. METHODS: Sixty-eight treatment-naïve glioma patients who underwent 18F-FDOPA PET and physiologic MRI were retrospectively selected (36 with isocitrate dehydrogenase wild-type [IDHwt], 16 with mutant 1p/19q noncodeleted [IDHm-noncodel], and 16 with mutant codeleted [IDHm-codel]). Fluid-attenuated inversion recovery hyperintense areas were segmented and used as regions of interest. For voxelwise and patientwise analyses, Pearson correlation coefficients (r voxelwise and r patientwise) between the normalized SUV (nSUV), rCBV, and ADC were evaluated. Cox regression analysis was performed to investigate the associations between overall survival and r voxelwise, maximum or median nSUV, median rCBV, or median ADC.
March 2021
Robotic Assistant Spinal Angiography: a Case Report and Technical Considerations.Robotic-assisted technology has shown to be promising in coronary and peripheral vascular interventions. Early case reports have also demonstrated its efficacy in neuro-interventions. However, there is no prior report demonstrating use of the robotic-assisted platform for spinal angiography. We report the feasibility of the robotic-assisted thoracic and lumbar spinal angiography.
February 2021
Case 286: Sarcoidlike Granulomatosis and Lymphadenopathy-Thoracic Manifestations of Nivolumab Drug Toxicity.History A 70-year-old man had a posterior left thigh lesion confirmed to be biopsy-proven melanoma. The patient underwent wide excision and sentinel node biopsy, which showed absence of residual melanoma. Two years later, the patient noticed a subcentimeter subcutaneous lump in his thigh. Repeat excisional biopsy showed involvement of the surrounding soft tissue, consistent with a satellite lesion. Follow-up combined PET/CT revealed satellite nodules around the primary lesion, enabling confirmation of subcutaneous metastatic disease. The patient was subsequently started on nivolumab, an anti-programmed cell death 1 (PD-1) immune checkpoint inhibitor that blocks PD-1 and is approved as a first-line treatment in patients with advanced metastatic melanoma. On the baseline scan prior to starting nivolumab, there were no CT findings that suggested metastatic disease, nor were there enlarged mediastinal or hilar lymph nodes. Five months after initiation of nivolumab treatment, the first follow-up chest CT scan was performed and showed new findings in the mediastinum and bilateral lungs. The patient remained asymptomatic during the treatment period. Furthermore, the subcutaneous metastatic disease remained stable during the treatment period, and no other site of metastatic disease was noted on follow-up CT scans obtained during the first 5 months of treatment. The patient had no prior history of infectious or occupational exposures. During the nivolumab treatment cycle, his pertinent laboratory values and physical examination findings were unremarkable.
February 2021
Radiographic Read Paradigms and the Roles of the Central Imaging Laboratory in Neuro-oncology Clinical Trials.Determination of therapeutic benefit in intracranial tumors is intimately dependent on serial assessment of radiographic images. The Response Assessment in Neuro-Oncology (RANO) criteria were established in 2010 to provide an updated framework to better characterize tumor response to contemporary treatments. Since this initial update a number of RANO criteria have provided some basic principles for the interpretation of changes on MR images; however, the details of how to operationalize RANO and other criteria for use in clinical trials are ambiguous and not standardized. In this review article designed for the neuro-oncologist or treating clinician, we outline essential steps for performing radiographic assessments by highlighting primary features of the Imaging Charter (referred to as the Charter for the remainder of this article), a document that describes the clinical trial imaging methodology and methods to ensure operationalization of the Charter into the workings of a clinical trial. Lastly, we provide recommendations for specific changes to optimize this methodology for neuro-oncology, including image registration, requirement of growing tumor for eligibility in trials of recurrent tumor, standardized image acquisition guidelines, and hybrid reader paradigms that allow for both unbiased measurements and more comprehensive interpretation.
February 2021
Using Digital Ethnography to Understand the Experience of Women With Pelvic Organ Prolapse.OBJECTIVE: To characterize the decision-making process and illness experience of women with pelvic organ prolapse (POP) using large-scale social media analysis. METHODS: Digital ethnographic analysis of online posts identified through data mining was performed. Grounded theory methodology was applied to 200 posts via traditional hand coding. To supplement our qualitative approach, we applied a Latent Dirichlet Allocation probabilistic topic modeling process to review the entire data set of identified posts to ensure thematic saturation.
February 2021
VIDEO: Dynamic Ultrasound for Snapping Hip Syndrome.OBJECTIVE: The purpose of this video article is to review the dynamic sonographic assessment of snapping hip syndrome. The video focuses on the extraarticular forms of snapping hip and discusses their possible causes, ultrasound features, and treatment options. The dynamic sonographic technique for evaluating snapping hip syndrome is shown with live scanning videos.
February 2021
Predicting Pathological Tumor Size in Prostate Cancer Based on Multiparametric Prostate Magnetic Resonance Imaging and Preoperative Findings.PURPOSE: Oncologic efficacy of focal therapies in prostate cancer depends heavily on accurate tumor size estimation. We aim to evaluate the agreement between radiologic tumor size and pathological tumor size, and identify predictors of pathological tumor size. MATERIALS AND METHODS: This single arm study cohort included all consecutive patients with biopsy proven prostate cancer and a corresponding PI-RADS®v2 3 or greater index tumor on multiparametric magnetic resonance imaging who subsequently underwent radical prostatectomy. Radiologic tumor size was defined as maximum tumor diameter on multiparametric magnetic resonance imaging and compared to whole mount histopathology tumor correlates. The difference between radiologic tumor size and pathological tumor size was assessed, and clinical, pathological and radiographic predictors of pathological tumor size were examined.
February 2021
White Matter of Perinatally HIV Infected Older Youths Shows Low Frequency Fluctuations that may Reflect Glial Cycling.In perinatally HIV-infected (PHIV) children, neurodevelopment occurs in the presence of HIV-infection, and even with combination antiretroviral therapy (cART) the brain can be a reservoir for latent HIV. Consequently, patients often demonstrate long-term cognitive deficits and developmental delay, which may be reflected in altered functional brain activity. Our objective was to examine brain function in PHIV on cART by quantifying the amplitude of low frequency fluctuations (ALFF) and regional homogeneity (ReHo). Further, we studied ALFF and ReHo changes with neuropsychological performance and measures of immune health including CD4 count and viral loads in the HIV-infected youths.
February 2021
Treatment of Post-Ablation Bronchopleural Fistula Using Percutaneous Synthetic Hydrogel Surgical Sealant: Initial Experience of Safety and Efficacy.PURPOSE: Bronchopleural fistula is a rare but serious complication of lung ablation, as it is difficult to treat and is associated with a high mortality rate. Standard therapy often relies on surgical pleurodesis, which can be particularly problematic in patients with poor baseline lung function. A minimally invasive treatment option for bronchopleural fistula may offer an alternative to surgery for appropriate patients. This case series describes the technique, safety and efficacy of percutaneously administered synthetic hydrogel surgical sealant in the treatment of post-ablation bronchopleural fistula in five patients. MATERIALS AND METHODS: Retrospective chart review was carried out in five consecutive patients identified to have had BPF after lung ablation between 2009 and 2017 who were treated with percutaneous administration of synthetic hydrogel surgical sealant using CT guidance.
February 2021
Influence of Phosphate Concentration on Amine, Amide, and Hydroxyl CEST Contrast.PURPOSE: To evaluate the influence of phosphate on amine, amide, and hydroxyl CEST contrast using Bloch-McConnell simulations applied to physical phantom data. METHODS: Phantom solutions of 4 representative metabolites with exchangeable protons-glycine (α-amine protons), Cr (η-amine protons), egg white protein (amide protons), and glucose (hydroxyl protons)-were prepared at different pH levels (5.6 to 8.9) and phosphate concentrations (5 to 80 mM). CEST images of the phantom were collected with CEST-EPI sequence at 3 tesla. The CEST data were then fitted to full Bloch-McConnell equation simulations to estimate the exchange rate constants. With the fitted parameters, simulations were performed to evaluate the intracellular and extracellular contributions of CEST signals in normal brain tissue and brain tumors, as well as in dynamic glucose-enhanced experiments.
January 2021
Eigenrank by Committee: Von-Neumann Entropy Based Data Subset Selection and Failure Prediction for Deep Learning Based Medical Image Segmentation.Manual delineation of anatomy on existing images is the basis of developing deep learning algorithms for medical image segmentation. However, manual segmentation is tedious. It is also expensive because clinician effort is necessary to ensure correctness of delineation. Consequently most algorithm development is based on a tiny fraction of the vast amount of imaging data collected at a medical center. Thus, selection of a subset of images from hospital databases for manual delineation - so that algorithms trained on such data are accurate and tolerant to variation, becomes an important challenge. We address this challenge using a novel algorithm. The proposed algorithm named 'Eigenrank by Committee' (EBC) first computes the degree of disagreement between segmentations generated by each DL model in a committee. Then, it iteratively adds to the committee, a DL model trained on cases where the disagreement is maximal. The disagreement between segmentations is quantified by the maximum eigenvalue of a Dice coefficient disagreement matrix a measure closely related to the Von Neumann entropy. We use EBC for selecting data subsets for manual labeling from a larger database of spinal canal segmentations as well as intervertebral disk segmentations. U-Nets trained on these subsets are used to generate segmentations on the remaining data. Similar sized data subsets are also randomly sampled from the respective databases, and U-Nets are trained on these random subsets as well. We found that U-Nets trained using data subsets selected by EBC, generate segmentations with higher average Dice coefficients on the rest of the database than U-Nets trained using random sampling (p < 0.05 using t-tests comparing averages). Furthermore, U-Nets trained using data subsets selected by EBC generate segmentations with a distribution of Dice coefficients that demonstrate significantly (p < 0.05 using Bartlett's test) lower variance in comparison to U-Nets trained using random sampling for all datasets. We believe that this lower variance indicates that U-Nets trained with EBC are more robust than U-Nets trained with random sampling.
January 2021
[Future of Cerebral Aneurysm Treatment].There has been an increasing role in the low invasive endovascular treatment of intracranial aneurysms. In addition to the detachable coils, the development of intracranial stents that are capable of repairing the parent artery itself has induced a significant treatment paradigm shift from open surgical to endovascular intervention. Recent evidence suggests that chronic inflammation plays a critical role in the process of intracranial aneurysm formation and rupture. It is, therefore, a natural evolution to seek drug treatments for intracranial aneurysms for growth or rupture prevention rather than any mechanical intervention. The authors review the current preclinical efforts on aneurysm drug treatments and prospective. Also covered is an emerging technology such as robotic endovascular treatment. The robotic system is capable of performing a subset of endovascular procedures such as stent-assisted aneurysm coiling. Although a lot of work needs to be done, remote health care is no longer science fiction.
January 2021
Effectiveness of Molecular Testing Techniques for Diagnosis of Indeterminate Thyroid Nodules: A Randomized Clinical Trial.IMPORTANCE: Approximately 20% of thyroid nodules display indeterminate cytology. Molecular testing can refine the risk of malignancy and reduce the need for diagnostic hemithyroidectomy. OBJECTIVE: To compare the diagnostic performance between an RNA test (Afirma genomic sequencing classifier) and DNA-RNA test (ThyroSeq v3 multigene genomic classifier). DESIGN, SETTING, & PARTICIPANTS: This parallel randomized clinical trial of monthly block randomization included patients in the UCLA Health system who underwent thyroid biopsy from August 2017 to January 2020 with indeterminate cytology (Bethesda System for Reporting Thyroid Cytopathology category III or IV). INTERVENTIONS: Molecular testing with the RNA test or DNA-RNA test. MAIN OUTCOMES & MEASURES: Diagnostic test performance of the RNA test compared with the DNA-RNA test. The secondary outcome was comparison of test performance with prior versions of the molecular tests.
January 2021
Call for a New Radiology Subspecialty in Imaging-Based Screening.Imaging-based screening has become a critical component of preventive care medicine, growing immensely over the past 50 years. Radiologists are at the center of this public health practice—we are the imaging experts—and yet we are underrepresented in the decision-making process that directs national screening practices. These decisions are largely made by primary care professionals and epidemiologists, who lack expertise in imaging. Here are two possible reasons for this: (1) Radiologists currently have minimal training in epidemiology and evidence development related to imaging-based screening, and (2) radiologists may be viewed as fundamentally biased in favor of imaging, resulting in a daily incentive toward more screening. As a solution, we propose a new radiology subspecialty—screening radiology—to help close the educational gap, untangle advocacy from science, and enable more effective radiology leadership in screening.
January 2021
Cardiac Magnetic Resonance Quantification of Structure-Function Relationships in Heart Failure.Classification of heart failure is based on the left ventricular ejection fraction (EF): preserved EF, midrange EF, and reduced EF. There remains an unmet need for further heart failure phenotyping of ventricular structure-function relationships. Because of high spatiotemporal resolution, cardiac magnetic resonance (CMR) remains the reference modality for quantification of ventricular contractile function. The authors aim to highlight novel frameworks, including theranostic use of ferumoxytol, to enable more efficient evaluation of ventricular function in heart failure patients who are also frequently anemic, and to discuss emerging quantitative CMR approaches for evaluation of ventricular structure-function relationships in heart failure.
January 2021
Malignancy in Giant Cell Tumor of Bone: Analysis of an Open-label Phase 2 Study of Denosumab.BACKGROUND: Giant cell tumor of bone (GCTB) is a rare osteoclastogenic stromal tumor. GCTB can rarely undergo malignant transformation. This post hoc analysis evaluated and classified malignancies in patients with GCTB who received denosumab. METHODS: This analysis was conducted on patients with pathologically confirmed GCTB and measurable active disease treated with denosumab 120 mg subcutaneously once every 4 weeks, with loading doses on study days 8 and 15, as part of a phase 2, open-label, multicenter study. We identified potential cases of malignancy related to GCTB through an independent multidisciplinary review or medical history, associated imaging or histopathologic reports, and disease course. The findings were summarized and no statistical analysis was performed.
January 2021
PI-RADS Version 2.1: A Critical Review, From the AJR Special Series on Radiology Reporting and Data Systems.PI-RADS version 2.1 updates the technical parameters for multiparametric MRI (mpMRI) of the prostate and revises the imaging interpretation criteria while maintaining the framework introduced in version 2. These changes have been considered an improvement, although some issues remain unresolved, and new issues have emerged. Areas for improvement discussed in this review include the need for more detailed mpMRI protocols with optimization for 1.5-T and 3-T systems; lack of validation of revised transition zone interpretation criteria and need for clarifications of the revised DWI and dynamic contrast-enhanced imaging criteria and central zone (CZ) assessment; the need for systematic evaluation and reporting of background changes in signal intensity in the prostate that can negatively affect cancer detection; creation of a new category for lesions that do not fit into the PI-RADS assessment categories (i.e., PI-RADS M category); inclusion of quantitative parameters beyond size to evaluate lesion aggressiveness; adjustments to the structured report template, including standardized assessment of the risk of extraprostatic extension; development of parameters for image quality and performance control; and suggestions for expansion of the system to other indications (e.g., active surveillance and recurrence).
January 2021
Inhibition of Mitochondrial Complex II in Neuronal Cells Triggers Unique Pathways Culminating in Autophagy with Implications for Neurodegeneration.Mitochondrial dysfunction and neurodegeneration underlie movement disorders such as Parkinson's disease, Huntington's disease and Manganism among others. As a corollary, inhibition of mitochondrial complex I (CI) and complex II (CII) by toxins 1-methyl-4-phenylpyridinium (MPP+) and 3-nitropropionic acid (3-NPA) respectively, induced degenerative changes noted in such neurodegenerative diseases. We aimed to unravel the down-stream pathways associated with CII inhibition and compared with CI inhibition and the Manganese (Mn) neurotoxicity. Genome-wide transcriptomics of N27 neuronal cells exposed to 3-NPA, compared with MPP+ and Mn revealed varied transcriptomic profile. Along with mitochondrial and synaptic pathways, Autophagy was the predominant pathway differentially regulated in the 3-NPA model with implications for neuronal survival. This pathway was unique to 3-NPA, as substantiated by in silico modelling of the three toxins. Morphological and biochemical validation of autophagy markers in the cell model of 3-NPA revealed incomplete autophagy mediated by mechanistic Target of Rapamycin Complex 2 (mTORC2) pathway. Interestingly, Brain Derived Neurotrophic Factor (BDNF), which was elevated in the 3-NPA model could confer neuroprotection against 3-NPA. We propose that, different downstream events are activated upon neurotoxin-dependent CII inhibition compared to other neurotoxins, with implications for movement disorders and regulation of autophagy could potentially offer neuroprotection.
