Performance of CT With Adrenal-Washout Protocol in Heterogeneous Adrenal Nodules: A Multiinstitutional Study.

Background: Adrenal-protocol CT is commonly performed to distinguish adrenal adenomas from other adrenal tumors. However, the technique's utility among heterogeneous nodules is not well established, and the optimal method for placing ROIs in heterogeneous nodules is not clearly defined. Objective: To determine the diagnostic performance of adrenal-protocol CT to distinguish adenomas from non-adenomas among heterogeneous adrenal nodules, and to compare this performance among different methods for ROI placement. Methods: This retrospective study including 164 patients (mean age, 59.1 years; 61 men, 103 women) from seven institutions, with a total of 164 heterogeneous adrenal nodules evaluated by adrenal-protocol CT. All nodules had an available pathologic reference standard. A single investigator at each institution evaluated CT images. ROIs were placed on portal venous phase images using four ROI methods: standard ROI, single large ROI in nodule center; high ROI, single ROI on nodule's highest-attenuation area; low ROI, single ROI on nodule's lowest-attenuation; average ROI: mean of three ROIs on nodule's superior, middle, and inferior thirds using the approach for the standard ROI. ROIs were then placed in identical locations on unenhanced and delayed phases. Absolute washout was determined for all methods. Results: The nodules comprised 82 adenomas and 82 non-adenomas (36 pheochromocytomas, 20 metastases, 12 adrenocortical carcinomas, and 14 with other pathologies). Mean nodule size was 4.5±2.8 cm (range, 1.6-23.0 cm). Unenhanced CT attenuation of 10 HU or less exhibited sensitivity and specificity for adenoma of 22.0% and 96.3% for standard ROI, 11.0% and 98.8% for high ROI, 58.5% and 84.1% for low ROI, and 30.5% and 97.6% for average ROI methods. Adrenal-protocol CT overall (unenhanced attenuation of 10 HU or less, or absolute washout of 60% or greater) exhibited sensitivity and specificity for adenoma of 57.3% and 84.1% for standard ROI, 63.4% and 51.2% for high ROI, 68.3% and 62.2% for low ROI, and 59.8% and 85.4% for average ROI methods. Conclusion: Adrenal-protocol CT has poor diagnostic performance for distinguishing adenomas from non-adenomas among heterogeneous adrenal nodules, regardless of the method used for ROI placement. Clinical Impact: Adrenal-protocol CT has limited utility in the evaluation of heterogeneous adrenal nodules.

Virtual Mentoring: A Guide to Navigating a New Age in Mentorship.

Mentorship is a fundamental part of professional and personal growth. Over time, the fabric of mentorship has been transforming from typical one-on-one mentor-mentee relationship to other types including peer, group, speed, and virtual mentoring. When the COVID-19 pandemic hit, it caused major disruptions in many facets of life and career, including mentoring. In response to the COVID-19 pandemic, live meetings were canceled, and social distancing measures were enacted at many institutions. Thus, the traditional set-up, with a face-to-face mentor and mentee interaction, was impossible. Many virtual platforms were utilized to navigate through these restrictions. In this review, we highlight challenges in mentorship during the COVID-19 pandemic and how we implemented different strategies to promote mentorship.

Vascular Anomaly Syndromes in the ISSVA Classification System: Imaging Findings and Role of Interventional Radiology in Management.

Vascular anomalies encompass a spectrum of tumors and malformations that can cause significant morbidity and mortality in children and adults. Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system is strongly recommended for consistency. Vascular anomalies can occur in isolation or in association with clinical syndromes that involve complex multifocal lesions affecting different organ systems. Thus, it is critical to be familiar with the differences and similarities among vascular anomalies to guide selection of the appropriate imaging studies and possible interventions. Syndromes associated with simple vascular malformations include hereditary hemorrhagic telangiectasia, blue rubber bleb nevus syndrome, Gorham-Stout disease, and primary lymphedema. Syndromes categorized as vascular malformations associated with other anomalies include Klippel-Trenaunay-Weber syndrome, Parkes Weber syndrome, Servelle-Martorell syndrome, Maffucci syndrome, macrocephaly-capillary malformation, CLOVES (congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and scoliosis, skeletal, and spinal anomalies) syndrome, Proteus syndrome, Bannayan-Riley-Ruvalcaba syndrome, and CLAPO (capillary malformations of the lower lip, lymphatic malformations of the face and neck, asymmetry of the face and limbs, and partial or generalized overgrowth) syndrome. With PHACES (posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects and/or coarctation of the aorta, eye abnormalities, and sternal clefting or supraumbilical raphe) syndrome, infantile hemangiomas associated with other lesions occur. Diagnostic and interventional radiologists have important roles in diagnosing these conditions and administering image-guided therapies-embolization and sclerotherapy, and different ablation procedures in particular. The key imaging features of vascular anomaly syndromes based on the 2018 ISSVA classification system and the role of interventional radiology in the management of these syndromes are reviewed. Online supplemental material is available for this article. ©RSNA, 2022.

Neurofibromatosis from Head to Toe: What the Radiologist Needs to Know.

Neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2) are autosomal dominant inherited neurocutaneous disorders or phakomatoses secondary to mutations in the NF1 and NF2 tumor suppressor genes, respectively. Although they share a common name, NF1 and NF2 are distinct disorders with a wide range of multisystem manifestations that include benign and malignant tumors. Imaging plays an essential role in diagnosis, surveillance, and management of individuals with NF1 and NF2. Therefore, it is crucial for radiologists to be familiar with the imaging features of NF1 and NF2 to allow prompt diagnosis and appropriate management. Key manifestations of NF1 include café-au-lait macules, axillary or inguinal freckling, neurofibromas or plexiform neurofibromas, optic pathway gliomas, Lisch nodules, and osseous lesions such as sphenoid dysplasia, all of which are considered diagnostic features of NF1. Other manifestations include focal areas of signal intensity in the brain, low-grade gliomas, interstitial lung disease, various abdominopelvic neoplasms, scoliosis, and vascular dysplasia. The various NF1-associated abdominopelvic neoplasms can be categorized by their cellular origin: neurogenic neoplasms, interstitial cells of Cajal neoplasms, neuroendocrine neoplasms, and embryonal neoplasms. Malignant peripheral nerve sheath tumors and intracranial tumors are the leading contributors to mortality in NF1. Classic manifestations of NF2 include schwannomas, meningiomas, and ependymomas. However, NF2 may have shared cutaneous manifestations with NF1. Lifelong multidisciplinary management is critical for patients with either disease. The authors highlight the genetics and molecular pathogenesis, clinical and pathologic features, imaging manifestations, and multidisciplinary management and surveillance of NF1 and NF2. Online supplemental material is available for this article. ©RSNA, 2022.

Review of uterine fibroids: imaging of typical and atypical features, variants, and mimics with emphasis on workup and FIGO classification.

Uterine fibroids are the most common gynecologic neoplasm. Although non-degenerated fibroids are easily identifiable on imaging, degenerated fibroids, fibroid variants, and fibroids with unusual growth patterns can constitute a diagnostic dilemma. Identification of these abnormal morphologic features can alter the diagnosis of presumed uterine fibroids and hence change management plans. This article reviews the typical and atypical radiologic imaging features of uterine fibroids, with an emphasis on the pitfalls, mimics, and radiologically identifiable features that can alter clinical management plans.

Gastrointestinal bleeding: imaging and interventions in cancer patients.

Gastrointestinal bleeding (GIB) among cancer patients is a major source of morbidity and mortality. Although a wide variety of etiologies contribute to GIB, special considerations should be made for cancer-related factors such as the type of malignancy, location and extent of disease, hemostatic parameters, and treatment effects. Key imaging modalities used to evaluate GIB include computed tomography angiography (CTA), radionuclide imaging, and catheter-based angiography. Understanding the cancer and treatment history and recognizing the associated imaging manifestations are important for identifying the source and potential causes of GIB in cancer patients. This article will review the common clinical presentations, causes, imaging manifestations, and angiographic management of GIB in cancer patients.

Acing the Fundamentals of Radiology: An Online Series for Medical Students and Interns.

PURPOSE: The current undergraduate radiology education predominantly integrates radiology with other disciplines during preclerkship years and is often taught by nonradiologists. Early exposure to radiology and profound understanding of scientific fundamentals of imaging modalities and techniques are essential for a better understanding and interest in the specialty. Furthermore, the COVID-19 pandemic-related impact on in-person medical education aggravated the need for alternative virtual teaching initiatives to provide essential knowledge to medical students. METHODS: The authors designed an online 7-session course on the principles of imaging modalities for medical students and fresh graduates in the United States and abroad. The course was delivered online and taught by radiologists from different US institutions. Pretests and posttests were delivered before and after each session, respectively, to assess change in knowledge. At the end of the course, a survey was distributed among students to collect their assessment and feedback. RESULTS: A total of 162 students and interns initially enrolled in the program by completing a sign-up interest form. An average of 65 participants attended each live session, with the highest attendance being 93 live attendees. An average of 44 attendees completed both the pretest and posttest for each session. There was a statistically significant increase in posttest scores compared with pretest scores ( P < 0.01) for each session; on average, the posttest scores were 48% higher than the pretest scores. A total of 84 participants answered the end-of-course survey. A total of 11% of the respondents described themselves as first year, 17% as second year, 18% as third year, 21% as fourth year, and 33% as "other." Attendees were enrolled in medical schools across 21 different countries with 35% of the respondents studying medicine in the United States. More than 76% of the respondents stated that they "strongly agree" that the program increased their understanding of radiology, increased their interest in radiology, and would be useful in their clinical practice in the future. Eighty-three percent of the respondents stated that they "strongly agree" that "this course was a worthwhile experience." Particularly, more than 84% of the respondents stated that among the most important components in enhancing their understanding of radiology were "the interpretation of normal imaging" and "interpretation of clinical cases." Ninety-two percent of the respondents stated that "the amount of effort to complete the requirements for this program was just right." Participants were also asked to rate each of the 8 sessions using the following scale: poor = 1 point, fair = 2, good = 3, and excellent = 4. The average rating for all 8 sessions was 3.61 points (SD = 0.55), which translates to 96% of the sessions being rated good or excellent. Eighty percent of the participants reported that the topics presented in the program were "excellent and clinically important to learn," and 20% of the participants reported that the topics presented were "good and somewhat important to learn." The participants were asked to evaluate their confidence regarding basic radiology skills before and after the program using the following scale: not confident at all = 1 point, somewhat confident = 2, moderately confident = 3, and very confident = 4. Figure 2 summarizes the responses of the participants. CONCLUSIONS: An online course to teach the fundamentals of imaging modalities could be delivered through a webinar format to medical students and interns in several countries to address the potential gaps in radiology education, therefore increasing their understanding of the different imaging modalities and their proper use in medicine.

Analyzing the Landscape of the 2021 Virtual Match: A Nationwide Survey of Radiology Programs' Stakeholders.

RATIONALE AND OBJECTIVES: We aimed to provide insights into the adaptive strategies, benefits, and challenges faced by the radiology programs during the 2021 residency virtual Match. Furthermore, we explored the potential impacts of related topics, such as diversity and social media use on the Match process and outcomes. MATERIALS AND METHODS: A cross-sectional survey of 31 questions was designed and distributed via e-mails to individuals involved radiology programs match process during the 2021 Match. Descriptive statistics were used to analyze the results of most questions. Two questions comparing the changes in factors influencing the selection of applicants on a Likert scale of 1-5 were analyzed using paired t-test and Wilcoxon signed-rank test where p-value <0.05 was considered statistically significant. RESULTS: Responses from 125 participants were analyzed. The following factors carried less weight in evaluating applicants during 2021 Match: away rotations (p < 0.01), no failed attempts in USMLE Step 1/CK (p < 0.01), grades in radiology clerkship (p < 0.04), and class rank/quartile (p < 0.04), while personal statements were more important (p < 0.03). Out of the 125 respondents, 80 (64%) and 58 (47%) strongly or somewhat agree on the effectiveness of virtual interviews in gauging applicants' candidacy and showing their programs' advantages, respectively. Advantages of virtual interviews included decreased cost, time flexibility, less faculty burden, and an increased number of offered interviews according to 81% (101/125), 46% (58/125), 40%, (50/125), and 34% (43/125), respectively. The most helpful platforms that showcased program advantages were program websites followed by Twitter and Instagram. CONCLUSION: Most radiology programs were able to adjust to the virtual interview process, and the majority agree on their effectiveness citing many benefits. However, there were mixed opinions if it could be sustained in future cycles.

Current update on molecular cytogenetics, diagnosis and management of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract and are thought to arise from precursors of the interstitial cells of Cajal. GISTs can arise anywhere in the GI tract, but most commonly originate from the stomach and small intestine. The majority of GISTs occur as a result of activating mutations in two receptor protein tyrosine kinases: KIT and/or platelet-derived growth factor receptor-α. Mutational analyses allow for predicting patient prognosis and treatment response. Clinical presentations can vary from no symptoms, typical in the case of small incidentally found tumors, to GI bleeding, abdominal discomfort, and ulcer-related symptoms when the tumor is enlarged. Imaging plays a critical role in the diagnosis and management of these tumors with multiphasic computed tomography serving as the imaging modality of choice. Magnetic resonance imaging and positron emission tomography-computed tomography can serve as imaging adjuncts in lesion characterization, especially with liver metastases, and subsequent staging and assessment for treatment response or recurrence. Surgical resection is the preferred management for small GISTs, while tyrosine kinase inhibitors - imatinib mesylate and sunitinib malate - serve as crucial molecular-targeted therapies for locally advanced and metastatic GISTs. This review article highlights the clinical presentation, pathology and molecular cytogenetics, imaging features, and current management of GISTs.

Features of primary pancreatic lymphoma: A bi-institutional review with an emphasis on typical and atypical imaging features.

BACKGROUND: Primary pancreatic lymphoma (PPL) is a rare neoplasm. Being able to distinguish it from other pancreatic malignancies such as pancreatic ductal adenocarcinoma (PDAC) is important for appropriate management. Unlike PDAC, PPL is highly sensitive to chemotherapy and usually does not require surgery. Therefore, being able to identify PPL preoperatively will not only direct physicians towards the correct avenue of treatment, it will also avoid unnecessary surgical intervention. AIM: To evaluate the typical and atypical multi-phasic computed tomography (CT) imaging features of PPL. METHODS: A retrospective review was conducted of the clinical, radiological, and pathological records of all subjects with pathologically proven PPL who presented to our institutions between January 2000 and December 2020. Institutional review board approval was obtained for this investigation. The collected data were analyzed for subject demographics, clinical presentation, laboratory values, CT imaging features, and the treatment received. Presence of all CT imaging findings including size, site, morphology and imaging characteristics of PPL such as the presence or absence of nodal, vascular and ductal involvement in these subjects were recorded. Only those subjects who had a pre-treatment multiphasic CT of the abdomen were included in the study. RESULTS: Twenty-nine cases of PPL were diagnosed between January 2000 and December 2020 (mean age 66 years; 13 males/16 females). All twenty-nine subjects were symptomatic but only 4 of the 29 subjects (14%) had B symptoms. Obstructive jaundice occurred in 24% of subjects. Elevated lactate dehydrogenase was seen in 81% of cases, whereas elevated cancer antigen 19-9 levels were present in only 10% of cases for which levels were recorded. The vast majority (90%) of tumors involved the pancreatic head and uncinate process. Mean tumor size was 7.8 cm (range, 4.0-13.8 cm). PPL presented homogenous hypoenhancement on CT in 72% of cases. Small volume peripancreatic lymphadenopathy was seen in 28% of subjects. Tumors demonstrated encasement of superior mesenteric vessels in 69% of cases but vascular stenosis or occlusion only manifested in 5 out of the twenty-nine individuals (17%). Mild pancreatic duct dilatation was also infrequent and seen in only 17% of cases, whereas common bile duct (CBD) dilation was seen in 41% of subjects. Necrosis occurred in 10% of cases. Size did not impact the prevalence of pancreatic and CBD dilation, necrosis, or mesenteric root infiltration (P = 0.525, P = 0.294, P = 0.543, and P = 0.097, respectively). Pancreatic atrophy was not present in any of the subjects. CONCLUSION: PPL is an uncommon diagnosis best made preoperatively to avoid unnecessary surgery and ensure adequate treatment. In addition to the typical CT findings of PPL, such as homogeneous hypoenhancement, absence of vascular stenosis and occlusion despite encasement, and peripancreatic lymphadenopathy, this study highlighted many less typical findings, including small volume necrosis and pancreatic and bile duct dilation.

Tuberous Sclerosis: Current Update.

Tuberous sclerosis complex (TSC) is a relatively rare autosomal dominant neurocutaneous disorder secondary to mutations in the TSC1 or TSC2 tumor suppressor genes. Although manifestation of the classic triad of seizures, intellectual disability, and facial angiofibromas may facilitate timely diagnosis of TSC, the multisystem features that may indicate TSC in the absence of these manifestations remain highly variable. In addition, patients with TSC are at risk of developing multiple benign and malignant tumors in various organ systems, resulting in increased morbidity and mortality. Thus, imaging plays a critical role in diagnosis, surveillance, and management of patients with TSC. It is crucial that radiologists be familiar with TSC and the various associated imaging features to avoid a delayed or incorrect diagnosis. Key manifestations include cortical dysplasias, subependymal nodules, subependymal giant cell astrocytomas, cardiac rhabdomyomas, lymphangioleiomyomatosis, and angiomyolipomas. Renal angiomyolipomas in particular can manifest with imaging features that mimic renal malignancy and pose a diagnostic dilemma. Other manifestations include dermatologic and ophthalmic manifestations, renal cysts, renal cell carcinomas, multifocal micronodular pneumocyte hyperplasia, splenic hamartomas, and other rare tumors such as perivascular epithelioid tumors. In addition to using imaging and clinical features to confirm the diagnosis, genetic testing can be performed. In this article, the molecular pathogenesis, clinical manifestations, and imaging features of TSC are reviewed. Current recommendations for management and surveillance of TSC are discussed as well. ©RSNA, 2021.

Current update on IVC leiomyosarcoma.

Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue sarcoma associated with poor prognosis. Patients are often asymptomatic or present with nonspecific abdominal symptoms, which delays initial diagnosis and contributes to poor oncologic outcome. Key imaging modalities include ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). Characteristic imaging features include imperceptible caval lumen, dilation of the IVC, heterogeneous enhancement of the tumor, and development of extensive collateral circulation. Surgical resection is the mainstay of treatment, while chemotherapy and/or radiation may serve as therapy adjuncts. This article reviews the pathology, clinical findings, imaging features and management of IVC leiomyosarcoma.

Imaging of pediatric cervical spine trauma.

While pediatric cervical spine injuries (CSI) are rare, they are associated with high morbidity and mortality and sometimes require expeditious surgical management. In this article, we aim to improve the diagnostic accuracy of pediatric CSI by reviewing normal pediatric cervical anatomy, typical pediatric CSI patterns, and common mimics of pediatric CSI. A literature review was conducted on pediatric CSI, its epidemiology, and the various imaging manifestations and mimics. The most common pediatric CSI occur in the upper cervical spine owing to the higher fulcrum and larger head at a young age, namely prior to age 9 years, while lower CSI occur more frequently in patients older than 9 years. While various craniocervical measurements may be utilized to identify craniocervical disruption, soft tissue injuries may be the only manifestation, thus making pediatric CSI difficult to diagnose on initial imaging. In the acute setting, CT cervical spine is an appropriate initial imaging modality for pediatric CSI evaluation. MRI serves as an additional tool to exclude or identify injuries when initial findings are equivocal. It is essential to recognize the unique anatomy and biomechanics of the pediatric spine and thus discern common pediatric CSI patterns and their mimics.

Metastatic basaloid squamous cell carcinoma of thymic origin.

A 57-year-old man with a known anterior mediastinal mass presented with abdominal distension, jaundice, and signs of urinary and bowel obstruction. Labs revealed leukocytosis, transaminitis, direct hyperbilirubinaemia and elevated levels of alkaline phosphatase, lactate dehydrogenase and uric acid. Subsequent imaging revealed the anterior mediastinal mass and diffuse liver lesions consistent with metastatic disease. MRI of the spine and brain were negative for metastases. Liver biopsy and immunohistochemistry revealed basaloid squamous cell carcinoma of thymic origin. Treatment with capecitabine was initiated but was complicated by worsening liver and kidney failure. Eventually, due to continued worsening of the patient's condition and minimal treatment response, capecitabine was stopped during cycle 1 and the patient was discharged to inpatient hospice with comfort care. In this case report, we highlight the presenting features, imaging findings and management of a patient with metastatic thymic carcinoma.

Spinal cord watershed infarction: Novel findings on magnetic resonance imaging.

Spinal cord watershed ischemia is a rare phenomenon often associated with cardiac arrest, prolonged hypotension, and atherosclerotic disease. It can manifest as central necrosis with peripheral sparing in the transverse axis, and central lesion with rostral and caudal sparing in the longitudinal axis. Few reports provide detailed imaging findings of spinal cord watershed ischemia lesions. We present a patient who experienced watershed infarcts of the brain and spinal cord following prolonged hypotension due to blood loss after an aortic aneurysm repair. The patient experienced loss of neurologic function of the lower extremities and left arm that did not recover following spinal cord ischemia protocol. MRI revealed spinal cord watershed ischemia in both the longitudinal and axial planes with the point of maximal T2 signal hyperintensity in the central cord at T10-T11. Unique findings included zones of central maximal T2 signal hyperintensity with peripheral sparing, and moderate T2 intensity representing partial ischemia between regions of maximal T2 intensity unaffected peripheral regions. Thoracoabdominal computed tomography angiogram revealed extensive intraluminal thrombus and bilateral spinal artery occlusion from T8 to L2 and bilateral severe renal artery stenosis. T7 and L3 spinal arteries were patent. We suspect preexisting atherosclerotic disease played a significant role in the development of widespread watershed lesions following prolonged hypotension and resulted in a clinical and imaging presentation distinct from that seen with isolated anterior spinal artery occlusion. Our unique MRI findings portray a rarely documented pattern of spinal cord watershed ischemia and prompt questions about the role of anatomic idiosyncrasies and preexisting vascular disease in the development of spinal cord watershed ischemia.

Manifestations of sickle cell disease on thoracic imaging.

Sickle cell disease is an inherited hemolytic disease with systemic complications. These complications significantly impact the patients' quality of life. There are characteristic radiological findings that can aid in the diagnosis and management of common sequelae of sickle cell disease. In this review, we will discuss the thoracic imaging findings of common complications of sickle cell disease in an organ-based approach and provide imaging examples of them.

Surgical management of leukoderma after burn: A review.

Burns are a common and sometimes devastating injury causing a significant amount of pain, disability, and occasionally death. Burns can have serious aesthetic and functional consequences such as pigmentary changes and formation of scar tissue. Hypopigmentation or depigmentation is often a result of partial- or full-thickness burns, which is referred to as leukoderma after burn. Thus, this study is aimed at systematically reviewing the surgical options for treating leukoderma after burn in order to gain insight into the advantages, disadvantages, and future implications of each surgical technique. The surgical procedures reviewed include dermabrasion with thin split thickness grafting, epidermal cell suspension spray, suction blister epidermal minigrafting, minigrafting, cultured epithelium, noncultured keratinocyte suspension, and chip skin grafting.

Oncocytoma: A Differential Consideration for an Incidentally Detected FDG-Avid Renal Mass on PET/CT.

Renal oncocytoma is a benign renal neoplasm that is often discovered incidentally and closely mimics renal cell carcinoma on common imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Due to the inability to reliably distinguish between these benign and malignant lesions with imaging, both are typically treated as if they are malignant. Hypermetabolic activity of renal oncocytomas is not frequently encountered because positron emission tomography (PET) is not a standard modality for imaging primary renal tumors. We present a case of a 65 year-old female with a history of thyroid cancer who had an incidentally discovered hypermetabolic renal mass on surveillance PET-CT imaging. Due to the concern for a primary renal malignancy or metastatic disease, the mass was resected and proven to be an oncocytoma on pathologic review.