June 2022
Radiofrequency Ablation of Solid, Non-Functional Thyroid Nodules.Thermal ablation in the neck has been applied to several clinical conditions, but by far, the most common application is for the treatment of the benign, solid, non-functional thyroid nodule. Though relatively new to the United States, thermal ablation of these nodules has been performed internationally for nearly two decades, especially in South Korea and Italy. A number of ablative techniques - radiofrequency, laser, microwave, high-intensity focused ultrasound, and ethanol - have been studied and reported. This review will focus on the most commonly applied technology for solid non-functional nodules, RFA.
June 2022
Diffusion MRI is an Early Biomarker of Overall Survival Benefit in IDH Wild-type Recurrent Glioblastoma Treated with Immune Checkpoint Inhibitors.BACKGROUND: Diffusion MRI estimates of the apparent diffusion coefficient (ADC) have been shown to be useful in predicting treatment response in patients with glioblastoma (GBM), with ADC elevations indicating tumor cell death. We aimed to investigate whether the ADC values measured before and after treatment with immune checkpoint inhibitors (ICIs) and the changes in these ADC values could predict overall survival (OS) in patients with recurrent IDH wild-type GBM. METHODS: Forty-four patients who met the following inclusion criteria were included in this retrospective study: (i) diagnosed with recurrent IDH wild-type GBM and treated with either pembrolizumab or nivolumab and (ii) availability of diffusion data on pre- and post-ICI MRI. Tumor volume and the median relative ADC (rADC) with respect to the normal-appearing white matter within the enhancing tumor were calculated.
June 2022
Free-breathing Radial Magnetic Resonance Elastography of the Liver in Children at 3 T: A Pilot Study.BACKGROUND: Magnetic resonance (MR) elastography of the liver measures hepatic stiffness, which correlates with the histopathological staging of liver fibrosis. Conventional Cartesian gradient-echo (GRE) MR elastography requires breath-holding, which is challenging for children. Non-Cartesian radial free-breathing MR elastography is a potential solution to this problem. OBJECTIVE: To investigate radial free-breathing MR elastography for measuring hepatic stiffness in children. MATHERIALS AND METHODS: In this prospective pilot study, 14 healthy children and 9 children with liver disease were scanned at 3 T using 2-D Cartesian GRE breath-hold MR elastography (22 s/slice) and 2-D radial GRE free-breathing MR elastography (163 s/slice). Each sequence was acquired twice. Agreement in the stiffness measurements was evaluated using Lin's concordance correlation coefficient (CCC) and within-subject mean difference. The repeatability was assessed using the within-subject coefficient of variation and intraclass correlation coefficient (ICC).
June 2022
Procedural Outcomes Associated with Use of the AngioVac System for Right Heart Thrombi: A Safety Report from RAPID Registry Data.BACKGROUND: Right heart thrombi can be a source of considerable morbidity and mortality, especially when associated with pulmonary embolism. METHODS: To understand the safety and procedural efficacy associated with vacuum-assisted thrombectomy using the AngioVac System (AngioDynamics, Latham, NY, USA) to remove right heart thrombi, we conducted a subanalysis of the Registry of AngioVac Procedures in Detail (RAPID) multicenter registry representing 47 (20.1%) of 234 participants in the registry. Forty-two (89.4%) patients had thrombi located in the right atrium alone, three (6.4%) in the right ventricle alone, and two (4.3%) in both the right atrium and ventricle. Four (8.5%) patients had concomitant caval thrombi, three (6.4%) also had catheter-related thrombi, and one (2.1%) patient had both caval and catheter-related thrombi with their right heart thrombi.
June 2022
Imaging Response Assessment for Oncology: An Algorithmic Approach.Treatment response assessment by imaging plays a vital role in evaluating changes in solid tumors during oncology therapeutic clinical trials. Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 is the reference standard imaging response criteria and provides details regarding image acquisition, image interpretation and categorical response classification. While RECIST 1.1 is applied for the majority of clinical trials in solid tumors, other criteria and modifications have been introduced when RECIST 1.1 outcomes may be incomplete. Available criteria beyond RECIST 1.1 can be explored in an algorithmic fashion dependent on imaging modality, tumor type and method of treatment. Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) is available for use with PET/CT. Modifications to RECIST 1.1 can be tumor specific, including mRECIST for hepatocellular carcinoma and mesothelioma. Choi criteria for gastrointestinal stromal tumors incorporate tumor density with alterations to categorical response thresholds. Prostate Cancer Working Group 3 (PCWG3) imaging criteria combine RECIST 1.1 findings with those of bone scans. In addition, multiple response criteria have been created to address atypical imaging responses in immunotherapy.
June 2022
Prostatic Artery Embolization for Treatment of Lower Urinary Tract Symptoms: A Markov Model-Based Cost-Effectiveness Analysis.PURPOSE: The aim of this study was to investigate whether prostatic artery embolization (PAE) can be considered a long-term cost-effective treatment option in patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia in comparison to transurethral resection of the prostate (TURP). METHODS: The in-hospital costs of PAE and TURP in the United States were obtained from a recent cost analysis. Clinical outcomes including nature and rate of adverse events for TURP and PAE along with rates of retreatment because of complications or clinical failure were obtained from peer-reviewed literature. A decision tree-based Markov model was created, analyzing long-term cost-effectiveness for TURP and PAE from a US health care sector perspective. Cost-effectiveness over a time frame of 5 years was estimated while assuming a willingness to pay of $50,000 per quality-adjusted life-year (QALY). The primary outcome was incremental cost-effectiveness ratio.
June 2022
Assessing the Aneurysm Occlusion Efficacy of a Shear-Thinning Biomaterial in a 3D-printed Model.Metallic coil embolization is a common method for the endovascular treatment of visceral artery aneurysms (VAA) and visceral artery pseudoaneurysms (VAPA); however, this treatment is suboptimal due to the high cost of coils, incomplete volume occlusion, poor reendothelialization, aneurysm puncture, and coil migration. Several alternative treatment strategies are available, including stent flow diverters, glue embolics, gelfoam slurries, and vascular mesh plugs-each of which have their own disadvantages. Here, we investigated the in vitro capability of a shear-thinning biomaterial (STB), a nanocomposite hydrogel composed of gelatin and silicate nanoplatelets, for the minimally-invasive occlusion of simple necked aneurysm models. We demonstrated the injectability of STB through various clinical catheters, engineered an in vitro testing apparatus to independently manipulate aneurysm neck diameter, fluid flow rate, and flow waveform, and tested the stability of STB within the models under various conditions.
June 2022
Head-to-Head Comparison of 68Ga-PSMA-11 PET/CT and mpMRI with a Histopathology Gold Standard in the Detection, Intraprostatic Localization, and Determination of Local Extension of Primary Prostate Cancer: Results from a Prospective Single-Center Imaging Trial.The role of prostate-specific membrane antigen (PSMA)-targeted PET in comparison to multiparametric MRI (mpMRI) in the evaluation of intraprostatic cancer foci is not well defined. The aim of our study was to compare the diagnostic performance of 68Ga-PSMA-11 PET/CT (PSMA PET/CT), mpMRI, and PSMA PET/CT + mpMRI using 3 independent masked readers for each modality and with histopathology as the gold standard in the detection, intraprostatic localization, and determination of local extension of primary prostate cancer. METHODS: Patients with intermediate- or high-risk prostate cancer who underwent PSMA PET/CT as part of a prospective trial (NCT03368547) and mpMRI before radical prostatectomy were included. Each imaging modality was interpreted by 3 independent readers who were unaware of the other modality result. A central majority rule was applied (2:1). Pathologic examination of whole-mount slices was used as the gold standard. Imaging scans and whole-mount slices were interpreted using the same standardized approach on a segment level and a lesion level. A "neighboring" approach was used to define imaging-pathology correlation for the detection of individual prostate cancer foci. Accuracy in determining the location, extraprostatic extension (EPE), and seminal vesicle invasion (SVI) of prostate cancer foci was assessed using receiver-operating-characteristic curve analysis. Interreader agreement was calculated using intraclass correlation coefficient analysis.
June 2022
Daily Functioning in Glioma Survivors: Associations with Cognitive Function, Psychological Factors and Quality of Life.AIM: Understanding and supporting quality of life (QoL) and daily functioning in glioma patients is a clinical imperative. In this study, we examined the relationship between cognition, psychological factors, measures of health-related QoL and functioning in glioma survivors. MATERIALS & METHODS: We examined neuropsychological, self-reported cognition, mood and QoL correlates of work and non-work-related daily functioning in 23 glioma survivors, and carried out linear models of the best predictors.
June 2022
Characterization of Cognitive Function in Survivors of Diffuse Gliomas Using Morphometric Correlation Networks.This pilot study investigates structural alterations and their relationships with cognitive function in survivors of diffuse gliomas. Twenty-four survivors of diffuse gliomas (mean age 44.5 ± 11.5), from whom high-resolution T1-weighted images, neuropsychological tests, and self-report questionnaires were obtained, were analyzed. Patients were grouped by degree of cognitive impairment, and interregional correlations of cortical thickness were computed to generate morphometric correlation networks (MCNs).
June 2022
Quantitative Image Analysis at Chronic Lung Allograft Dysfunction Onset Predicts Mortality.BACKGROUND: Chronic lung allograft dysfunction (CLAD) phenotype determines prognosis and may have therapeutic implications. Despite the clarity achieved by recent consensus statement definitions, their reliance on radiologic interpretation introduces subjectivity. The Center for Computer Vision and Imaging Biomarkers at the University of California, Los Angeles (UCLA) has established protocols for chest high-resolution computed tomography (HRCT)-based computer-aided quantification of both interstitial disease and air-trapping. We applied quantitative image analysis (QIA) at CLAD onset to demonstrate radiographic phenotypes with clinical implications. METHODS: We studied 47 first bilateral lung transplant recipients at UCLA with chest HRCT performed within 90 d of CLAD onset and 47 no-CLAD control HRCTs. QIA determined the proportion of lung volume affected by interstitial disease and air-trapping in total lung capacity and residual volume images, respectively. We compared QIA scores between no-CLAD and CLAD, and between phenotypes. We also assigned radiographic phenotypes based solely on QIA, and compared their survival outcomes.
May 2022
Machine Learning Automated Detection of Large Vessel Occlusion From Mobile Stroke Unit Computed Tomography Angiography.BACKGROUND: Prehospital automated large vessel occlusion (LVO) detection in Mobile Stroke Units (MSUs) could accelerate identification and treatment of patients with LVO acute ischemic stroke. Here, we evaluate the performance of a machine learning (ML) model on CT angiograms (CTAs) obtained from 2 MSUs to detect LVO. METHODS: Patients evaluated on MSUs in Houston and Los Angeles with out-of-hospital CTAs were identified. Anterior circulation LVO was defined as an occlusion of the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery vessels and determined by an expert human reader. A ML model to detect LVO was trained and tested on independent data sets consisting of in-hospital CTAs and then tested on MSU CTA images. Model performance was determined using area under the receiver-operator curve statistics.
May 2022
Reconstruction of Carotid Stenosis Hemodynamics Based on Guidewire Pressure Data and Computational Modeling.A comparative analysis between intravascular guidewire-obtained and computational fluid dynamic (CFD) flow velocity and pressure data using simplified carotid stenosis models was performed. This information was used to evaluate the viability of using guidewire pressure data to provide inlet conditions for CFD flow, and to study the relationship between stenotic length and hemodynamic behavior. Carotid stenosis models differing in diameter and length were prepared and connected to a vascular pulsatile flow simulator. Time-dependent flow velocity and pressure measurements were taken by microcatheter guidewires and compared with CFD data. Guidewire and CFD-generated pressure profiles matched closely in all measurement locations. The guidewire was unable to reliably measure flow velocity at areas associated with higher CFD flow velocities (r = 0.92). CFD results showed that an increased length of stenosis generated expansive regions of elevated wall shear stress (WSS) within and distal to the stenosis. Low WSS was found immediately outside the stenosis outlet. An increase in stenotic length produced higher flow velocities with minimal lengthening of the distal high velocity flow jet due to faster dissipation of translational kinetic energy through turbulence. We found the accuracy of guidewire-obtained velocity measurements is limited to regions unaffected by disturbed flow. WSS and turbulence behavior distal to the stenosis may be important markers to evaluate the severity of atherosclerotic progression as a function of stenotic length.
May 2022
Volumetric Measurements are Preferred in the Evaluation of Mutant IDH Inhibition in Non-enhancing Diffuse Gliomas: Evidence from a Phase I Trial of Ivosidenib.BACKGROUND: Since IDH-mutant (mIDH) low-grade gliomas (LGGs) progress slowly and have a relatively long survival, there is a significant need for earlier measurements of clinical benefit. Guidance using the LGG RANO criteria recommends serial bidirectional (2D) measurements on a single slice; however, questions remain as to whether volumetric (3D) measurements are better, since they would allow for more accurate measurements in irregular shaped lesions and allow readers to better assess areas of subtle change. METHODS: Twenty-one (out of 24) non-enhancing, recurrent mIDH1 LGGs were enrolled in a phase I, multicenter, open-label study of oral ivosidenib (NCT02073994), and with imaging pre- and post-treatment as part of this exploratory ad hoc analysis. 2D and 3D measurements on T2-weighted FLAIR images were centrally evaluated at an imaging contract research organization using a paired read and forced adjudication paradigm. The effects of 2D vs 3D measurements on progression-free survival (PFS), growth rate measurement variability, and reader concordance and adjudication rates were quantified.
May 2022
Prostate Cancer Multiparametric Magnetic Resonance Imaging Visibility is a Tumor-Intrinsic Phenomena.Multiparametric magnetic resonance imaging (mpMRI) is an emerging standard for diagnosing and prognosing prostate cancer, but ~ 20% of clinically significant tumors are invisible to mpMRI, as defined by the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) score of one or two. To understand the biological underpinnings of tumor visibility on mpMRI, we examined the proteomes of forty clinically significant tumors (i.e., International Society of Urological Pathology (ISUP) Grade Group 2)-twenty mpMRI-visible and twenty mpMRI-invisible, with matched histologically normal prostate. Normal prostate tissue was indistinguishable between patients with visible and invisible tumors, and invisible tumors closely resembled the normal prostate. These data indicate that mpMRI-visibility arises when tumor evolution leads to large-magnitude proteomic divergences from histologically normal prostate.
May 2022
North American Study for the Treatment of Recurrent Epistaxis with Doxycycline: The NOSTRIL Trial.BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a vascular bleeding disorder characterized by mucocutaneous telangiectasias and visceral arteriovenous malformations. A frequently debilitating symptom is spontaneous recurrent epistaxis. OBJECTIVE: To evaluate whether doxycycline therapy improves epistaxis in HHT by using a prospective, randomized, placebo-controlled crossover study design. PATIENTS/METHODS: Twenty-two eligible patients between December 2017 and July 2020 at a single center were randomized to one of two study arms: doxycycline treatment followed by placebo, or vice versa. Primary outcomes measured differences in epistaxis severity between treatments. Changes in quality of life, laboratory markers of bleeding, and number of monthly blood transfusions or iron infusions were assessed as secondary endpoints. Additional post hoc endpoints included frequency and duration of dripping epistaxis and gushing epistaxis. A post hoc longitudinal analysis assessed effects of doxycycline over time.
May 2022
A Readily Scalable, Clinically Demonstrated, Antibiofouling Zwitterionic Surface Treatment for Implantable Medical Devices.Unlike growth on tissue, microbes can grow freely on implantable devices with minimal immune system intervention and often form resilient biofilms that continuously pump out pathogenic cells. The efficacy of antibiotics used to treat infection is declining due to increased rates of pathogenic resistance. A simple, one-step zwitterionic surface modification is developed to significantly reduce protein and microbial adhesion to synthetic materials and demonstrate the successful modification of several clinically relevant materials, including recalcitrant materials such as elastomeric polydimethylsiloxane. The treated surfaces exhibit robust adhesion resistance against proteins and microorganisms in both static and flow conditions. Furthermore, the surface treatment prevents the adhesion of mammalian fibroblast cells while displaying no cytotoxicity. To demonstrate the clinical efficacy of the novel technology in the real-world, a surface-treated, commercial silicone foley catheter is developed that is cleared for use by the U.S. Food and Drug Administration (K192034). 16 long-term catheterized patients received surface-treated catheters and completed a Patient Global Impression of Improvement (PGI-I) questionnaire. 10 out of 16 patients described their urinary tract condition post implantation as "much better" or "very much better" and 72% (n = 13) of patients desire to continue using the surface-treated catheter over conventional latex or silicone catheters.
May 2022
Orbital Vascular Malformations: Determining Outflow with Valsalva Maneuver-Augmented Computed Tomography Angiography.Accurately characterizing the hemodynamic properties of an orbital vascular malformation (VM) is critical to executing a safe and effective management plan. Dynamic dual-phase Valsalva maneuver-augmented computed tomography angiography (CTA) provides valuable information with respect to the lesion's physio-logic features and often is performed as part of the investigation matrix in cases of orbital VMs.
May 2022
Complete Robotic Intervention for Acute Epistaxis in a Patient with COVID-19 Pneumonia: Technical Considerations and Device Selection Tips.The use of robot-assisted technology is expanding in interventional laboratories with an increasing number of reports of effective treatment delivery in neurointerventional procedures. Here we report the feasibility of complete robot-assisted neurointervention including the guide catheter and microcatheter manipulations with subsequent embolization of the arterial source of hemorrhage in a patient hospitalized with severe COVID-19 complicated by acute epistaxis.
May 2022
Early Radiographic Progression of Scleroderma: Lung Disease Predicts Long-term Mortality.BACKGROUND: Radiographic end points commonly are included in therapeutic trials for systemic sclerosis (SSc)-interstitial lung disease (ILD); however, the relationship between these outcomes and long-term mortality is unclear. RESEARCH QUESTION: Do short-term changes in radiographic measures of ILD predict long-term survival in patients with SSc? STUDY DESIGN AND METHODS: The Scleroderma Lung Study (SLS) I and II evaluated the safety and efficacy of cyclophosphamide (in SLS I and II) and mycophenolate mofetil (in SLS II) for the treatment of SSc-ILD. Changes in the extent of ILD over time were assessed on high-resolution CT scans of the chest by quantitative image analysis, an approach that applies a computer-based algorithm to assess changes in the radiographic extent of ILD objectively. Participants subsequently were followed for up to 12 years (SLS I) and 8 years (SLS II). Cox proportional hazards models determined whether the change in the quantitative radiographic extent of ILD predicted survival, adjusting for other known predictors of survival.
May 2022
Diagnostic and Prognostic Value of pH- and Oxygen-Sensitive Magnetic Resonance Imaging in Glioma: A Retrospective Study.Characterization of hypoxia and tissue acidosis could advance the understanding of glioma biology and improve patient management. In this study, we evaluated the ability of a pH- and oxygen-sensitive magnetic resonance imaging (MRI) technique to differentiate glioma genotypes, including isocitrate dehydrogenase (IDH) mutation, 1p/19q co-deletion, and epidermal growth factor receptor (EGFR) amplification, and investigated its prognostic value. A total of 159 adult glioma patients were scanned with pH- and oxygen-sensitive MRI at 3T. We quantified the pH-sensitive measure of magnetization transfer ratio asymmetry (MTRasym) and oxygen-sensitive measure of R2' within the tumor region-of-interest.
April 2022
Update on Social Media Use in Breast Radiology.The term social media refers to a computer-based technology that facilitates the sharing of ideas, thoughts, and information through virtual networks and communities. Social media is internet-based and allows users to engage in quick, electronic communication of material such as personal information, documents, videos, and photos. There are more than 4.5 billion users around the world who access social media via computer, tablet, or smartphone using web-based software or applications. At its inception, social media was used to promote interactions between friends and family, but it has since been widely adopted by businesses, which use it to reach customers. The power of social media lies in its ability to connect and share information with many people simultaneously and its ability to facilitate two-way communication between individuals or groups. Some of the largest social media networks available today include Facebook (FB), Instagram (IG), Twitter, YouTube, and TikTok. By the year 2023, the number of social media users in the United States alone is predicted to be approximately 257 million. According to the Pew Research Center, social media users tend to be younger (18-29 years), better educated, and relatively wealthy.
April 2022
A Rare Aneurysmal Bone Cyst of the Rib in an Infant: A Case ReportAn aneurysmal bone cyst (ABC) is a rare benign expansile lesion of the bone that consists of hemorrhagic cystic spaces separated by fibrous connective tissue containing osteoid and multinucleated giant cells. The lesion may be primary or secondary. We present a case of ABC in a 7-month-old girl who had a growing, antibiotic-refractory mass in the left chest wall. A computed tomography of the chest confirmed the anatomic location of the mass, but a percutaneous image-guided biopsy and video-assisted thoracoscopic surgery performed during work-up were nondiagnostic. The patient ultimately had a partial rib resection via left thoracotomy. On histologic examination, the...
April 2022
Congenital Intrahepatic Portosystemic Shunt with Invasive Hepatocellular Carcinoma.A 60-year-old man with a history of congenital intrahepatic portosystemic shunt (CIPS) presented with acute bilateral lower-extremity edema. There were no stigmata of chronic liver disease. However, mildly abnormal liver function tests and ɑ-fetoprotein 79.1 ng/mL were noted. Subsequent imaging revealed a 8 cm right lobe liver mass, extending into the right hepatic vein into the IVC and right atrium (A,B). An 8 mm side-to-side intrahepatic shunt between the right portal vein and the IVC (C,D — CT; E – US) was confirmed. A transfemoral biopsy of the IVC lesion demonstrated a poorly differentiated HCC (F). A CIPS is rare. The overall incidence is 1:30,000 births and 1:50,000 for those beyond early life. Because of a reduced portal flow and compensatorily increased hepatic arterial flow in CIPS, benign nodular liver lesions are common. However, HCC is very rare. In fact, IVC and right atrial tumor thrombi arising from HCC due to CIPS are extremely rare and result a poor prognosis (median survival of 1-4 months).
April 2022
Hepatic Plexus Nerve Block for Microwave Ablation of Hepatic Tumors.Seven patients underwent microwave ablation of hepatic tumors; during ablation, a hepatic nerve plexus block was used for pain control. The mean visual analog scale (VAS) score for pain (scale, 0-10) was 0.3 ± 0.5 (SD) at baseline and 2.5 ± 1.4, 2.6 ± 1.4, and 2.3 ± 0.9 at 1, 5, and 10 minutes during ablation. Two patients reported a VAS score of 4 or greater during ablation, which improved in both patients to a VAS score of 3 after one rescue sedation dose. The remaining patients required no additional sedation. No major complication occurred. No patient required conversion to general anesthesia.
April 2022
Endovascular Biopsy of a Sigmoid Sinus Lesion using a Stent Retriever and Aspiration Catheter.A teenager with a history of acute myeloid leukemia presented with headache, nausea and blurry vision over a 2 week period. The MRI of the brain was concerning for the presence of a myeloid sarcoma within the right sigmoid sinus. For evaluation of venous obstruction and the underlying lesion the patient underwent a cerebral angiogram and transvenous biopsy of the sigmoid sinus lesion using a stent retriever and aspiration catheter. The tissue extracted was consistent with myeloid sarcoma. This pathologic finding was consistent with the recurrence of leukemia and guided the targeted oncologic treatment.
April 2022
Magnetic Resonance Imaging-Guided Biopsy in Active Surveillance of Prostate Cancer.PURPOSE: The underlying premise of prostate cancer active surveillance (AS) is that cancers likely to metastasize will be recognized and eliminated before cancer-related disease can ensue. Our study was designed to determine the prostate cancer upgrading rate when biopsy guided by magnetic resonance imaging (MRGBx) is used before entry and during AS. MATERIALS AND METHODS: The cohort included 519 men with low- or intermediate-risk prostate cancer who enrolled in prospective studies (NCT00949819 and NCT00102544) between February 2008 and February 2020. Subjects were preliminarily diagnosed with Gleason Grade Group (GG) 1 cancer; AS began when subsequent MRGBx confirmed GG1 or GG2. Participants underwent confirmatory MRGBx (targeted and systematic) followed by surveillance MRGBx approximately every 12 to 24 months. The primary outcome was tumor upgrading to ≥GG3.
April 2022
Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome: A Case ReportA 1-day-old girl, late preterm (36 weeks 3 days) infant, was admitted to the neonatal intensive care unit for respiratory distress and megacystis seen on a prenatal ultrasound at 24 weeks of gestation. A babygram (anteroposterior view of the entire body) showed absence of bowel gas, and abdominal ultrasound revealed grade 4 bilateral hydronephrosis. The patient was subsequently diagnosed with megacystis-microcolon-intestinal hypoperistalsis syndrome and was taken to the operating room for appropriate treatment.
April 2022
Atrioventricular Discordance with Pulmonary Atresia, Double-outlet Right Ventricle, and Isolated Levocardia: A Case Report of a Rare Congenital Heart DiseaseAlmost all cases of isolated levocardia or situs inversus with levocardia are associated with congenital heart disease. We report a case of situs inversus with levocardia, double-outlet right ventricle, atrioventricular discordance, pulmonary atresia, patent ductus arteriosus, atrial septal defect, and ventricular septal defect in a neonate. An overview of anatomy and relevant definitions with radiographic correlation will be presented along with a synopsis of current medical literature...
March 2022
Olfactory Neuroblastoma: Re-Evaluating the Paradigm of Intracranial Extension and Cyst Formation.The purpose of the current study was to assess the prevalence of cyst formation at the brain-tumor interface in olfactory neuroblastoma. We used the UCLA patient-based Pathology and Radiology Head and Neck Database (UPP&R HAND) to identify the largest patient cohort reported to date with imaging and pathology data. Eighteen of thirty-one patients (58.1%) had evidence of intracranial extension on MRI, while four (22.0%) demonstrated cyst formation at the brain-tumor interface. The extent of intracranial extension was by far the strongest predictor for intracranial cyst formation, regardless of Hyams tumor grade, using a binary logistics regression model (p = 0.002) and ROC curve analysis (AUC 94.6%). Cyst formation at the brain-tumor interface was an uncommon imaging finding, and tends to occur with a larger component of intracranial tumor extension.
March 2022
MR Angiography Series: Noncardiac Chest MR Angiography.This review guides readers through the selection and setup of standardized noncardiac chest MRA protocols, including contrast-enhanced MRA (CE-MRA) and noncontrast MRA (NC-MRA), sequences that can be used in a variety of clinical situations. After reviewing basic principles described in the first three tutorials in this series on CE-MRA and NC-MRA, this online presentation details the use of MRA in specific clinical scenarios: thoracic aortic aneurysm, aortic dissection, congenital heart disease, vasculitis, central veins, and pulmonary embolus. Tips and tricks for optimization of the sequences, image acquisition, and image interpretation are provided. This module is the fourth in a series created on behalf of the Society for Magnetic Resonance Angiography (SMRA), a group of researchers and clinicians who are passionate about the benefits of MRA but understand its challenges.
March 2022
Paradoxical Association Between Relative Cerebral Blood Volume Dynamics Following Chemoradiation and Increased Progression-Free Survival in Newly Diagnosed IDH Wild-Type MGMT Promoter Methylated Glioblastoma With Measurable Disease.BACKGROUND & PURPOSE: While relative cerebral blood volume (rCBV) may be diagnostic and prognostic for survival in glioblastoma (GBM), changes in rCBV during chemoradiation in the subset of newly diagnosed GBM with subtotal resection and the impact of MGMT promoter methylation status on survival have not been explored. This study aimed to investigate the association between rCBV response, MGMT methylation status, and progression-free (PFS) and overall survival (OS) in newly diagnosed GBM with measurable enhancing lesions. METHODS: 1,153 newly diagnosed IDH wild-type GBM patients were screened and 53 patients (4.6%) had measurable post-surgical tumor (>1mL). rCBV was measured before and after patients underwent chemoradiation. Patients with a decrease in rCBV >10% were considered rCBV Responders, while patients with an increase or a decrease in rCBV <10% were considered rCBV Non-Responders. The association between change in enhancing tumor volume, change in rCBV, MGMT promotor methylation status, and PFS or OS were explored.
March 2022
Comparison of Combined Transarterial Chemoembolization and Ablations in Patients with Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.PURPOSE: This systematic review and meta-analysis compares the efficacy of three combination therapies, including transarterial chemoembolization (TACE) with radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CRA) for the treatment of patients with hepatocellular carcinoma (HCC). METHODS: Online databases, including Scopus, Web of Science, PubMed, Embase, CNKI, Google Scholar, and Cochrane Library were searched.
March 2022
A Prostate Cancer Risk Calculator: Use of Clinical and Magnetic Resonance Imaging Data to Predict Biopsy Outcome in North American Men.INTRODUCTION: A functional tool to optimize patient selection for magnetic resonance imaging (MRI)-guided prostate biopsy (MRGB) is an unmet clinical need. We sought to develop a prostate cancer risk calculator (PCRC-MRI) that combines MRI and clinical characteristics to aid decision-making for MRGB in North American men. METHODS: Two prospective registries containing 2354 consecutive men undergoing MRGB (September 2009 to April 2019) were analyzed. Patients were randomized into five groups, with one group randomly assigned to be the validation cohort against the other four groups as the discovery cohort. The primary outcome was detection of clinically significant prostate cancer (csPCa) defined as Gleason grade group ≥2. Variables included age, ethnicity, digital rectal exam (DRE), prior biopsy, prostate-specific antigen (PSA), prostate volume, PSA density, and MRI score. Odds ratios (OR) were calculated from multivariate logistic regression comparing two models: one with clinical variables only (clinical) against a second combining clinical variables with MRI data (clinical+MRI).
March 2022
High-resolution Three-dimensional Contrast-enhanced Magnetic Resonance Venography in Children: Comparison of Gadofosveset Trisodium with Ferumoxytol.BACKGROUND: Gadofosveset is a gadolinium-based blood pool contrast agent that was approved by the United States Food and Drug Administration in 2008. Its unanticipated withdrawal from production in 2016 created a void in the blood pool agent inventory and highlighted the need for an alternative agent with comparable imaging properties. OBJECTIVE: The purpose of our study is to compare the diagnostic image quality, vascular contrast-to-noise ratio (CNR) and temporal signal characteristics of gadofosveset trisodium and ferumoxytol at similar molar doses for high-resolution, three-dimensional (3-D) magnetic resonance (MR) venography in children. MATERIALS & METHODS: The medical records and imaging data sets of patients who underwent high-resolution 3-D gadofosveset-enhanced MR venography (GE-MRV) or ferumoxytol-enhanced MR venography (FE-MRV) were retrospectively reviewed. Two groups of 20 pediatric patients (age- and weight-matched with one patient common to both groups; age range: 2 days-15 years) who underwent high-resolution 3-D GE-MRV or FE-MRV at similar molar doses were identified and analyzed. Qualitative analysis of image quality and vessel definition was performed by two blinded pediatric radiologists. Interobserver agreement was assessed with the AC1 (first-order agreement coefficient) statistic. Signal-to-noise ratio (SNR) and CNR of the inferior vena cava and aorta were measured in the steady-state venous phase. Medical records were retrospectively reviewed for any adverse reactions associated with either contrast agent.
March 2022
Refining Epileptogenic High-frequency Oscillations Using Deep Learning: A Reverse Engineering Approach.Intracranially recorded interictal high-frequency oscillations have been proposed as a promising spatial biomarker of the epileptogenic zone. However, its visual verification is time-consuming and exhibits poor inter-rater reliability. Furthermore, no method is currently available to distinguish high-frequency oscillations generated from the epileptogenic zone (epileptogenic high-frequency oscillations) from those generated from other areas (non-epileptogenic high-frequency oscillations). To address these issues, we constructed a deep learning-based algorithm using chronic intracranial EEG data via subdural grids from 19 children with medication-resistant neocortical epilepsy to: (i) replicate human expert annotation of artefacts and high-frequency oscillations with or without spikes, and (ii) discover epileptogenic high-frequency oscillations by designing a novel weakly supervised model. The 'purification power' of deep learning is then used to automatically relabel the high-frequency oscillations to distill epileptogenic high-frequency oscillations. Using 12 958 annotated high-frequency oscillation events from 19 patients, the model achieved 96.3% accuracy on artefact detection (F1 score = 96.8%) and 86.5% accuracy on classifying high-frequency oscillations with or without spikes (F1 score = 80.8%) using patient-wise cross-validation.
February 2022
Introducing Pre-Health Students to Radiology Utilizing Virtual Shadowing through Social Media.Aspiring physicians typically know less about radiology compared to other specialties and are often unaware of how medical imaging is interpreted or what a radiologist does. Prior studies have focused on improving radiology education in medical school, as it is taught by non radiologists at many institutions (1) or as a senior elective, when students have already decided on their specialty. A study by Fielding et al demonstrated that only 15% of medical students participating in a third or fourth year radiology clinical clerkship planned on going into radiology.
February 2022
The Paralabral Cyst: A Mimicker of Axillary Lymphadenopathy in the Setting of COVID-19 Vaccination.A 55-year-old woman was called back from screening mammography because of left axillary lymphadenopathy (Fig. 1A). She had received the second dose of Pfizer COVID-19 vaccine in the left deltoid 2 weeks before the screening examination. Targeted ultrasound showed reactive axillary lymph nodes and a separate round mass inferomedial to the humeral head (Fig. 1B). Subsequent shoulder MRI showed an inferior lobulated paralabral cyst (Fig. 1C) that accounted for the mammographic finding. Recent COVID-19 vacci-nation poses a diagnostic dilemma for women undergoing screening mammography. Unilateral axillary lymphadenopathy in this setting is often reactive, but the imaging findings are nonspecific. The Society of Breast Imaging [1] recommends short-term sonographic follow-up to document improvement. In rare instances, paralabral cysts may resemble reactive axillary lymph nodes [2]. Paralabral cysts are associated with labral tears and can cause pain, weakness, and denervation of the supraspinatus and infraspinatus muscles secondary to nerve compression. These are benign and do not require intervention or imaging follow-up.
February 2022
Perioperative Skeletal Muscle Fluctuations in High-Acuity Liver Transplantation.BACKGROUND: Frailty has been implicated as a negative predictor of Liver Transplant (LT) outcomes. However, an understanding of changes in patient muscle mass peri-LT, and their effect in high-acuity patients remains lacking. We examined the impact of perioperative muscle mass changes (ΔSMI) on high-acuity (MELD ≥35) LT recipients. MATERIALS AND METHODS: Skeletal muscle index (SMI) was calculated using CT imaging. Patients were divided into two groups, based on severity of peri-operative SMI decrease. LT recipients with chronic end-stage liver disease, MELD ≥35, and abdominal CT ≤ 30 days prior, and 30-90 days post LT were included. [1011 adult LT recipients reviewed, 2012-2018].
February 2022
Non-invasive Stereotactic Body Radiation Therapy for Refractory Ventricular Arrhythmias: Venturing into the Unknown.Stereotactic body radiation therapy (SBRT) is a promising new method for non-invasive management of life-threatening ventricular arrhythmias. Numerous case reports and case series have provided encouraging short-term results suggesting good efficacy and safety, but randomized data and long-term outcomes are not yet available. The primary hypothesis as to the mechanism of action for SBRT relates to the development of cardiac fibrosis in arrhythmogenic myocardial substrate; however, limited animal model data offer conflicting insights into this theory. The use of SBRT for patients with refractory ventricular arrhythmias is rapidly increasing, but ongoing translational science work and randomized clinical trials will be critical to address many outstanding questions regarding this novel therapy.
February 2022
Surgical Ablation after Stereotactic Body Radiation Therapy for Ventricular Arrhythmias.Catheter ablation remains the principal intervention to target scar-based, macroreentrant ventricular arrhythmias. However, the use of stereotactic body radiation therapy (SBRT) for recurrent ventricular arrhythmias is becoming increasingly common, with initial case reports and case series describing promising early results, particularly in patients who are poor candidates for, or have failed, catheter ablation procedures. Nonetheless, many questions remain as to the mechanism of action, safety, and long-term efficacy. In this report, we expand upon a case that has been briefly described previously that provides important insights into the limitations of SBRT in a patient who required open chest surgical ablation after failing SBRT.
February 2022
Imaging Advances for Central Nervous System Tumors.This article reviews recent advances in the use of standard and advanced imaging techniques for diagnosis and treatment of central nervous system (CNS) tumors, including glioma and brain metastasis. Following the recent transition from a histology-based approach in classifying CNS tumors to one that integrates histology with the molecular information of tumor, the approaches for imaging CNS tumors have also been adapted to this new framework. Some challenges related to the diagnosis and treatment of CNS tumors, such as differentiating tumor from treatment-related imaging changes, require further progress to implement advanced imaging for clinical use.
February 2022
Effects of Irreversible Electroporation on Femoral Nerves in a Rabbit Model.INTRODUCTION: Irreversible electroporation (IRE) is a novel technique that uses a non-thermal ablation to avoid adjacent major structure injury. The aim of this study was to sequentially evaluate the effects of IRE on the femoral nerve during acute-to-delayed periods in a rabbit model. MATERIAL AND METHODS: Ultrasound-guided IRE of femoral neurovascular bundles was performed in seven rabbits. Functional and histopathologic evaluation was performed sequentially after IRE. The extent of nerve fiber affected, and the proportion of perineurial inflammation and surrounding tissue injury were recorded.
February 2022
Polysplenia Syndrome and Sickle Cell Trait: Extensive Deep Venous Thrombosis from Venous Stasis and Hypercoagulability.Deep venous thrombosis is a hitherto under-recognized complication occurring in patients with polysplenia syndrome, despite the high prevalence of venous anomalies such as interrupted inferior vena cava (IVC) with azygos/hemiazygos continuation. Here we report the first case of concurrent polysplenia (as evidenced by interrupted IVC with azygos/hemiazygos continuation, multiple left-sided spleens, bowel malrotation with inverted mesenteric veins, preduodenal portal vein, and pancreatic hypoplasia/partial agenesis of the dorsal pancreas) and sickle cell trait, complicated by extensive deep venous thrombosis refractory to medical and interventional radiologic management.
February 2022
Breast Imaging for Transgender Individuals: Assessment of Current Practice and Needs.PURPOSE: The aim of this study was to investigate breast radiologists' practices related to recording sex and gender in the electronic medical record, knowledge and attitudes about breast cancer screening recommendations for transgender individuals, and experience and willingness to enter screening mammography data from transgender patients into databases that document service provision and outcomes of cancer detection protocols. METHODS: A 19-question anonymous survey was distributed by e-mail to all active physician members of the Society of Breast Imaging. Response characteristics were assessed as frequencies and percentages and compared between groups using the Fisher exact test or 𝛘2 test. The degree of agreement between questions was assessed using the McNemar test.
February 2022
Percutaneous Direct Puncture and Embolization of Vascularly Inaccessible Abdominal Visceral Pseudoaneurysms: A Single-center Experience and Literature Review.BACKGROUND: To evaluate the techniques, efficacy, and safety for treating vascularly inaccessible abdominal visceral pseudoaneurysms by direct puncture and embolization. METHODS: A retrospective study of 5 consecutive patients who underwent percutaneous direct puncture embolization for intra-abdominal pseudoaneurysms in our institution between January 2009 and December 2016. Technical aspects, success, clinical outcome, and complications were discussed.
February 2022
Characterization of Cognitive Function in Survivors of Diffuse Gliomas Using Resting-state Functional MRI (rs-fMRI).As treatments for diffuse gliomas have advanced, survival for patients with gliomas has also increased. However, there remains limited knowledge on the relationships between brain connectivity and the lasting changes to cognitive function that glioma survivors often experience long after completing treatment. This resting-state functional magnetic resonance imaging (rs-fMRI) study explored functional connectivity (FC) alterations associated with cognitive function in survivors of gliomas. In this pilot study, 22 patients (mean age 43.8 ± 11.9) with diffuse gliomas who completed treatment within the past 10 years were evaluated using rs-fMRI and neuropsychological measures. Novel rs-fMRI analysis methods were used to account for missing brain in the resection cavity. FC relationships were assessed between cognitively impaired and non-impaired glioma patients, along with self-reported cognitive impairment, non-work daily functioning, and time with surgery. In the cognitively non-impaired patients, FC was stronger in the medial prefrontal cortex, rostral prefrontal cortex, and intraparietal sulcus compared to the impaired survivors. When examining non-work daily functioning, a positive correlation with FC was observed between the accumbens and the intracalcarine cortices, while a negative correlation with FC was observed between the parietal operculum cortex and the cerebellum. Additionally, worse self-reported cognitive impairment and worse non-work daily functioning were associated with increased FC between regions involved in cognition and sensorimotor processing. These preliminary findings suggest that neural correlates for cognitive and daily functioning in glioma patients can be revealed using rs-fMRI. Resting-state network alterations may serve as a biomarker for patients' cognition and functioning.
February 2022
Safety of 3 Tesla Magnetic Resonance Imaging in Patients With Auditory Brainstem Implants.OBJECTIVE: To evaluate the safety of 3 Tesla (T) magnetic resonance imaging (MRI) in patients with auditory brainstem implants (ABI) with the magnet removed at implantation and report incidence of complications. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary neurotology ambulatory practice. PATIENTS: Patients with diagnosis of Neurofibromatosis, type 2 (NF2) with functional ABIs.
February 2022
Breast Papillomas in the United States: Single Institution Data on Underrepresented Minorities with a Multi-institutional Update on Incidence.PURPOSE: To assess the percentage of papillomas from all biopsies performed, comparing differences in patient age and race at a single institution. To assess trends in biopsied papillomas at institutions throughout the United States (US). METHODS: This is a HIPPA-compliant IRB-approved single-institution (Southern1) retrospective review to assess race and age of all-modality-biopsied non-malignant papillomas as a percentage of all biopsies (percentage papillomas calculated as papilloma biopsies/all biopsies) from January 2012 to December 2019. To assess national variation, several academic or large referral centers were contacted to provide data regarding papilloma percentages, biopsy modalities, and trends in case numbers. Trends were estimated using the method of analysis of variance (ANOVA). Comparisons of differences in trends were assessed.
January 2022
Free-breathing 3D Stack-of-radial MRI Quantification of Liver Fat and R2* in Adults with Fatty Liver Disease.PURPOSE: To investigate the agreement, intra-session repeatability, and inter-reader agreement of liver proton-density fat fraction (PDFF) and R2* quantification using free-breathing 3D stack-of-radial MRI, with and without self-gated motion compensation, compared to reference breath-hold techniques in subjects with fatty liver disease (FLD). METHODS: In this institutional review board-approved prospective study, thirty-eight adults with FLD and/or iron overload (24 male, 58 ± 12 years) were imaged at 3T using free-breathing stack-of-radial MRI, breath-hold 3D Cartesian MRI, and breath-hold single-voxel MR spectroscopy (SVS). Each sequence was acquired twice in random order. To assess agreement compared to reference breath-hold techniques, the dependency of liver PDFF and/or R2* quantification on the sequence, radial sampling factor, and radial self-gating temporal resolution was assessed by calculating the Bayesian mean difference (MDB) of the posteriors. Intra-session repeatability and inter-reader agreement (two independent readers) were assessed by the coefficient of repeatability (CR) and intraclass correlation coefficient (ICC), respectively.
January 2022
Public Interest in Prostatic Artery Embolization: An Analysis of Search Query DataBACKGROUND: Prostatic artery embolization (PAE) is an emerging treatment for benign prostatic hyperplasia (BPH). However, changes in public interest in PAE over time, especially relative to interest in alternative BPH treatments, are difficult to assess. The online tool for analysis of the popularity of top search queries (Google Trends; Alphabet Inc) provides a relative search volume (RSV) of specified keywords and insight about patterns of user searches. PURPOSE: The purpose of this study is to assess changes in public interest in PAE over time and compare them with changes in public interest in alternative BPH treatments as indicated by search queries. MATERIAL AND METHODS: Using Google Trends, we identified the RSV of specified keywords within search queries submitted between 2010 and 2019 in the United States. The RSVs of keywords with high search volume were identified and normalized on a scale of values from 0 to 100. Interest in PAE was assessed by comparing RSVs and trends of the keyword PAE as well as of other prostate-treatment-related keywords. Prostate embolization was a PAE-related, BPH-treatment-specific keyword with the highest average RSV. A linear regression analysis was performed to characterize annual search trends of the use of these keywords. Subsequently, the annual search trend of prostate embolization was compared with that of keywords related to transurethral resection of the prostate (TURP) and minimally invasive surgical treatments (MISTs).
January 2022
Trends that Impact IR's Future.The future of IR will evolve as a result of current trends in advances in medicine, disease biology, technology, and IR devices and accoutrements. Changes in the trends that lie at the center of the differentiation of IR from other treatment specialties will have the greatest impact. Differentiation revolves around image guidance knowledge and procedural treatment skills and involves three key components: access, mapping, and action, all of which have the common thread of imaging knowledge. The main trends that are discussed are: image-guided diagnostics (IgDx), image-guided treatment (IgRx), sub-specialization in IgRx, large device design for IgRx, multimodality IgRx, interdisciplinary IgRx, and decentralized IgRx growth. Success in attaining a patient-facing "front-line" patient position will determine the future not only of IR but of radiology as a field. IgRx is anti-commoditization immunization...
January 2022
Laser Ablation of Human Guilt.Fourteen-year-old girl (AB) with no previous medical illness began to notice brief but distinct episodes of guilt and distress, occasionally followed by urinary incontinence. In the beginning, the patient attributed these feelings to recent or ongoing events such as "fighting with friends" or "doing something wrong at school". With time, she became increasingly baffled by these episodes, trying to "figure out if the situation was causing guilt" (Supplamentary Table 1). These episodes were noted by the patient to be more frequent in social-affective situations, such as standing in front of large groups or arguing with her parents. For nearly a year the patient kept these episodes to herself until she had a generalized tonic clonic seizure, leading to neurological consultation and epilepsy diagnosis. Although the patient was treated with multiple anti-seizure medications, the episodes did not abate.
January 2022
Visibility & Support for First Generation College Graduates in Medicine.State-of-the-art diagnosis of radiculopathy relies on "highly subjective" radiologist interpretation of magnetic resonance imaging of the lower back. Currently, the treatment of lumbar radiculopathy and associated lower back pain lacks coherence due to an absence of reliable, objective diagnostic biomarkers. Using emerging machine learning techniques, the subjectivity of interpretation may be replaced by the objectivity of automated analysis. However, training computer vision methods requires a curated database of imaging data containing anatomical delineations vetted by a team of human experts. In this chapter, we outline our efforts to develop such a database of curated imaging data alongside the required delineations. We detail the processes involved in data acquisition and subsequent annotation. Then we explain how the resulting database can be utilized to develop a machine learning-based objective imaging biomarker. Finally, we present an explanation of how we validate our machine learning-based anatomy delineation algorithms. Ultimately, we hope to allow validated machine learning models to be used to generate objective biomarkers from imaging data-for clinical use to diagnose lumbar radiculopathy and guide associated treatment plans.
January 2022
Imaging Biomarker Development for Lower Back Pain Using Machine Learning: How Image Analysis Can Help Back Pain.State-of-the-art diagnosis of radiculopathy relies on "highly subjective" radiologist interpretation of magnetic resonance imaging of the lower back. Currently, the treatment of lumbar radiculopathy and associated lower back pain lacks coherence due to an absence of reliable, objective diagnostic biomarkers. Using emerging machine learning techniques, the subjectivity of interpretation may be replaced by the objectivity of automated analysis. However, training computer vision methods requires a curated database of imaging data containing anatomical delineations vetted by a team of human experts. In this chapter, we outline our efforts to develop such a database of curated imaging data alongside the required delineations. We detail the processes involved in data acquisition and subsequent annotation. Then we explain how the resulting database can be utilized to develop a machine learning-based objective imaging biomarker. Finally, we present an explanation of how we validate our machine learning-based anatomy delineation algorithms. Ultimately, we hope to allow validated machine learning models to be used to generate objective biomarkers from imaging data-for clinical use to diagnose lumbar radiculopathy and guide associated treatment plans.
January 2022
Primary Extranodal NK/T-Cell Lymphoma Presenting as Neurolymphomatosis Involving Multiple Cranial Nerves: A Case Report.Neurolymphomatosis (NL) is a rare condition caused by the lymphomatous or leukemic infiltration of nerves and manifests as neuropathy. Most often, NL is associated with B-lineage non-Hodgkin lymphoma (NHL) and only infrequently occurs in conjunction with T- or NK-lineage NHL. Extranodal NK/T-cell lymphoma (ENKTL)-associated NL is exceedingly unusual, with only 9 cases described in the English language literature, in addition to our case. Diagnosis of NL is challenging, as the entity can mimic neuropathies of more common etiologies, and an adequate biopsy may be difficult to obtain. Timely diagnosis demands a high index of suspicion, especially for patients without a history of hematologic malignancy. We expand upon a unique case of NL exclusively involving cranial nerves and cauda equina nerve roots, as the initial manifestation of ENKTL, and contextualize our findings within the framework of previously reported NK/T-lineage NL cases.
January 2022
Visualization of Tumor Heterogeneity and Prediction of Isocitrate Dehydrogenase Mutation Status for Human Gliomas Using Multiparametric Physiologic and Metabolic MRI.This study aimed to differentiate isocitrate dehydrogenase (IDH) mutation status with the voxel-wise clustering method of multiparametric magnetic resonance imaging (MRI) and to discover biological underpinnings of the clusters. A total of 69 patients with treatment-naïve diffuse glioma were scanned with pH-sensitive amine chemical exchange saturation transfer MRI, diffusion-weighted imaging, fluid-attenuated inversion recovery, and contrast-enhanced T1-weighted imaging at 3 T. An unsupervised two-level clustering approach was used for feature extraction from acquired images. The logarithmic ratio of the labels in each class within tumor regions was applied to a support vector machine to differentiate IDH status. The highest performance to predict IDH mutation status was found for 10-class clustering, with a mean area under the curve, accuracy, sensitivity, and specificity of 0.94, 0.91, 0.90, and 0.91, respectively. Targeted biopsies revealed that the tissues with labels 7-10 showed high expression levels of hypoxia-inducible factor 1-alpha, glucose transporter 3, and hexokinase 2, which are typical of IDH wild-type glioma, whereas those with labels 1 showed low expression of these proteins. In conclusion, A machine learning model successfully predicted the IDH mutation status of gliomas, and the resulting clusters properly reflected the metabolic status of the tumors.
January 2022
Arterial and Venous Thrombotic Complications in Patients with COVID-19: A Report of Three CasesCoronavirus Disease 2019 (COVID-19) has had an enormous impact on both the medical community as well as society as a whole. Research on the pathogenesis and the treatment of the disease is rapidly emerging, with new observations and hypotheses appearing daily. One aspect that has been receiving increasing attention is the occurrence of both arterial and venous thrombotic complications in patients with COVID-19. We report three cases of thromboembolic complications in patients affected by COVID-19 and discuss clinical features, pathophysiology, and the proposed approaches to management of vascular complications in these patients. Through our discussion, we also urge physicians to be vigilant for any symptoms or signs suggestive of thrombosis in patients with COVID-19.
January 2022
Sarcopenia in High Acuity Liver Transplantation: Does it Predict Outcomes?BACKGROUND: Sarcopenia has gained momentum as a potential risk-stratification tool in liver transplantation (LT). While LT recipients recently have more advanced end-stage liver disease, the impact of sarcopenia in high acuity recipients with a high model for end-stage liver disease (MELD) score remains unclear. METHODS: We retrospectively assessed sarcopenia by calculating skeletal muscle index (SMI) from cross-sectional area at third lumbar vertebra (cm2) and height (m2) in 296 patients with a CT ≤ 30 days prior to LT. Sex-specific SMI cut-offs were developed, and its impact was assessed in patients with MELD ≥ 35.
January 2022
Automatic Triangulated Mesh Generation of Pulmonary Airways from Segmented Lung 3DCTs for Computational Fluid Dynamics.PURPOSE: Computational fluid dynamics (CFD) of lung airflow during normal and pathophysiological breathing provides insight into regional pulmonary ventilation. By integrating CFD methods with 4D lung imaging workflows, regions of normal pulmonary function can be spared during treatment planning. To facilitate the use of CFD simulations in a clinical setup, a robust, automated, and CFD-compliant airway mesh generation technique is necessary. METHODS: We define a CFD-compliant airway mesh to be devoid of blockages of airflow and leaks in the airway path, both of which are caused by airway meshing errors that occur when using conventional meshing techniques. We present an algorithm to create a CFD-compliant airway mesh in an automated manner. Beginning with a medial skeleton of the airway segmentation, the branches were tracked, and 3D points at which bifurcations occur were identified. Airway branches and bifurcation features were isolated to allow for automated and careful meshing that considered their anatomical nature.
January 2022
High Resolution Histopathology Image Generation and Segmentation Through Adversarial Training.Semantic segmentation of histopathology images can be a vital aspect of computer-aided diagnosis, and deep learning models have been effectively applied to this task with varying levels of success. However, their impact has been limited due to the small size of fully annotated datasets. Data augmentation is one avenue to address this limitation. Generative Adversarial Networks (GANs) have shown promise in this respect, but previous work has focused mostly on classification tasks applied to MR and CT images, both of which have lower resolution and scale than histopathology images. There is limited research that applies GANs as a data augmentation approach for large-scale image semantic segmentation, which requires high-quality image-mask pairs. In this work, we propose a multi-scale conditional GAN for high-resolution, large-scale histopathology image generation and segmentation. Our model consists of a pyramid of GAN structures, each responsible for generating and segmenting images at a different scale. Using semantic masks, the generative component of our model is able to synthesize histopathology images that are visually realistic. We demonstrate that these synthesized images along with their masks can be used to boost segmentation performance, especially in the semi-supervised scenario.
January 2022
Patient Adherence to Lung CT Screening Reporting & Data System-Recommended Screening Intervals in the United States: A Systematic Review and Meta-Analysis.Lung cancer screening (LCS) is effective in reducing mortality, particularly when patients adhere to follow-up recommendations standardized by the Lung CT Screening Reporting & Data System (Lung-RADS). Nevertheless, patient adherence to recommended intervals varies, potentially diminishing benefit from screening. We conducted a systematic review and meta-analysis of patient adherence to Lung-RADS-recommended screening intervals. We systematically searched MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and major radiology and oncology conference archives between April 28, 2014, and December 17, 2020. Eligible studies mentioned patient adherence to the recommendations of Lung-RADS. The review protocol was registered with PROSPERO (CRD42020189326). We identified 24 eligible studies for qualitative summary, of which 21 were suitable for meta-analysis.
January 2022
Peripheral Non-cerebrovascular Arterial Stent Retriever Applications.Several treatment options exist for acute intra-abdominal arterial thromboembolic events, including systemic thrombolytics, endovascular therapy, and less commonly surgery. A novel alternative treatment intervention for acute intra-abdominal arterial thrombus is the use of stent retriever (SR) devices, tools traditionally applied for treatment of acute vascular thrombosis in stroke patients. This brief report presents two cases of acute intra-abdominal arterial thrombosis successfully managed by deployment of SRs. Furthermore, it details the history, device mechanism, and design of SRs and describes cases in literature involving effective extracranial SR application.
January 2022
Electronic Health Record-Integrated Tumor Board Application to Save Preparation Time and Reduce Errors.PURPOSE: Multidisciplinary oncology meetings, or tumor boards (TBs), ensure and facilitate communication between specialties regarding the management of cancer cases to improve patient care. The organization of TB and the preparation and presentation of patient cases are typically inefficient processes that require the exchange of patient information via e-mail, the hunting for data and images in the electronic health record, and the copying and pasting of patient data into desktop presentation software. METHODS: We implemented a standards-based electronic health record-integrated application that automated several aspects of TB organization and preparation. We hypothesized that this application would increase the efficiency of TB preparation, reduce errors in patient entry, and enhance communication with the clinical team. Our experimental design used a prospective evaluation by pathologists who were timed in preparing for weekly TBs using both the new application and the conventional method. In addition, patient data entry errors associated with each method were tracked, and TB attendees completed a survey evaluating satisfaction with the new application.
January 2022
Steady-state Ferumoxytol-enhanced MRI: Early Observations in Benign Abdominal Organ Masses and Clinical Implications.INTRODUCTION: The off-label use of ferumoxytol as a vascular MR imaging agent is growing rapidly. However, the properties of ferumoxytol suggest that it may play an important role in the detection and characterization of abdominal mass lesions. METHODS: Thirty-six patients with benign abdominal mass lesions who underwent MR angiography with ferumoxytol also had T2-weighted HASTE imaging and fat-suppressed 3D T1-weighted imaging. The T1 and T2 enhancement characteristics of the lesions were analyzed and correlated with other imaging modalities and/or surgical findings and/or clinical follow-up.
January 2022
A Randomized Phase II Study of Nivolumab Monotherapy or Nivolumab Combined with Ipilimumab in Patients with Advanced Gastrointestinal Stromal Tumors.PURPOSE: Most gastrointestinal stromal tumors (GIST) are driven by KIT/PDGFRa mutations. Tyrosine kinase inhibitor benefit is progressively less after imatinib failure. This phase II trial analyzed the efficacy of nivolumab (N) or nivolumab + ipilimumab (N + I) in patients with refractory GIST. PATIENTS AND METHODS: Patients with advanced/metastatic GIST refractory to at least imatinib were randomized 1:1 in a noncomparative, parallel group, unblinded phase II trial of N (240 mg every 2 weeks) or N + I (240 mg every 2 weeks + 1 mg/kg every 6 weeks). The primary endpoint was the objective response rate of N alone or N+I by RECIST 1.1 in the intent-to-treat population.
January 2022
AngioVac Aspiration of Right Atrial Cardiac Pacemaker Lead-associated Thrombus with Concurrent PE under Fluoroscopic and Transesophageal Echocardiographic Guidance: a Multidisciplinary Collaboration for Improved Patient Outcome.In the U.S., pulmonary embolism (PE) is a common cause of cardiovascular death. Right heart thrombus (RHT) occurs in approximately 4% of patients with PE, and when concurrent is associated with increased 30-day PE-related and all-cause mortality. The consensus on optimal management of acute massive or high-risk PE is unclear, and even less so for concurrent RHT. In this report, we review a successful multidisciplinary coordination of vacuum-assisted thrombectomy (VAT) of a complex pacemaker lead-associated RHT in a patient with concurrent acute PE and significant comorbidities, using the AngioVac system (Vortex Medical, Norwell, MA). VAT is a reasonable treatment option that should be considered particularly for patients who are poor surgical or thrombolytic candidates. Procedural success and patient outcomes can be further optimized through multidisciplinary collaboration such as with the Pulmonary Embolism Response Team (PERT) model.
January 2022
Accelerated k-space Shift Calibration for Free-Breathing Stack-of-radial MRI Quantification of Liver Fat and R2*PURPOSE: To develop an accelerated k-space shift calibration method for free-breathing 3D stack-of-radial MRI quantification of liver proton-density fat fraction (PDFF) and R2* METHODS: Accelerated k-space shift calibration was developed to partially skip acquisition of k-space shift data in the through-plane direction then interpolate in processing, as well as to reduce the in-plane averages. A multi-echo stack-of-radial sequence with the baseline calibration was evaluated on a phantom versus vendor-provided reference-standard PDFF and R2* values at 1.5T, and in 13 healthy subjects and 5 clinical subjects at 3T with respect to reference-standard breath-hold Cartesian acquisitions. PDFF and R2* maps were calculated with different calibration acceleration factors offline and compared to reference-standard values using Bland-Altman analysis. Bias and uncertainty were evaluated using normal distribution and Bayesian probability of difference (P < .05 considered significant).
