Perirenal lymphatics: anatomy, pathophysiology, and imaging spectrum of diseases.

Despite being rarely discussed, perinephric lymphatics are involved in many pathological and benign processes. The lymphatic system in the kidneys has a harmonious dynamic with ureteral and venous outflow, which can result in pathology when this dynamic is disturbed. Although limited by the small size of lymphatics, multiple established and emerging imaging techniques are available to visualize perinephric lymphatics. Manifestations of perirenal pathology may be in the form of dilation of perirenal lymphatics, as with peripelvic cysts and lymphangiectasia. Lymphatic collections may also occur, either congenital or as a sequela of renal surgery or transplantation. The perirenal lymphatics are also intimately involved in lymphoproliferative disorders, such as lymphoma as well as the malignant spread of disease. Although these pathologic entities often have overlapping imaging features, some have distinguishing characteristics that can suggest the diagnosis when paired with the clinical history.

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.

Extraskeletal Ewing Sarcoma from Head to Toe: Multimodality Imaging Review.

Extraskeletal Ewing sarcoma (EES) is a rare subtype in the Ewing sarcoma family of tumors (ESFT), which also includes Ewing sarcoma of bone (ESB) and, more recently, primitive neuroectodermal tumors. Although these tumors often have different manifestations, they are grouped on the basis of common genetic translocation and diagnosis from specific molecular and immunohistochemical features. While the large majority of ESFT cases occur in children and in bones, approximately 25% originate outside the skeleton as EES. Importantly, in the adult population these extraskeletal tumors are more common than ESB. Imaging findings of EES tumors are generally nonspecific, with some variation based on location and the tissues involved. A large tumor with central necrosis that does not cross the midline is typical. Despite often nonspecific findings, imaging plays an important role in the evaluation and management of ESFT, with MRI frequently the preferred imaging modality for primary tumor assessment and local staging. Chest CT and fluorine 18 fluorodeoxyglucose PET/CT are most sensitive for detecting lung and other distant or nodal metastases. Management often involves chemotherapy with local surgical excision, when possible. A multidisciplinary treatment approach should be used given the propensity for large tumor size and local invasion, which can make resection difficult. Despite limited data, outcomes are similar to those of other ESFT cases, with 5-year survival exceeding 80%. However, with metastatic disease, the long-term prognosis is poor. ©RSNA, 2022.

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.

Artificial Intelligence in Diagnostic Radiology: Where Do We Stand, Challenges, and Opportunities.

ABSTRACT: Artificial intelligence (AI) is the most revolutionizing development in the health care industry in the current decade, with diagnostic imaging having the greatest share in such development. Machine learning and deep learning (DL) are subclasses of AI that show breakthrough performance in image analysis. They have become the state of the art in the field of image classification and recognition. Machine learning deals with the extraction of the important characteristic features from images, whereas DL uses neural networks to solve such problems with better performance. In this review, we discuss the current applications of machine learning and DL in the field of diagnostic radiology.Deep learning applications can be divided into medical imaging analysis and applications beyond analysis. In the field of medical imaging analysis, deep convolutional neural networks are used for image classification, lesion detection, and segmentation. Also used are recurrent neural networks when extracting information from electronic medical records and to augment the use of convolutional neural networks in the field of image classification. Generative adversarial networks have been explicitly used in generating high-resolution computed tomography and magnetic resonance images and to map computed tomography images from the corresponding magnetic resonance imaging. Beyond image analysis, DL can be used for quality control, workflow organization, and reporting.In this article, we review the most current AI models used in medical imaging research, providing a brief explanation of the various models described in the literature within the past 5 years. Emphasis is placed on the various DL models, as they are the most state-of-art in imaging analysis.

Imaging characteristics of pathologically proven adrenal adenomas with myelolipomatous degeneration: correlation with clinical and pathologic features.

OBJECTIVES: Adrenal adenoma with myelolipomatous degeneration (AMD) is a rarely reported and often overlooked entity. The aim of this study is to improve understanding of these lesions by characterizing the imaging findings with pathologic and clinical correlation. METHODS: In the largest series to date, we report 11 nodules in 11 patients confirmed with a pathologic diagnosis of AMD. The available cross-sectional imaging and histopathologic features were reviewed by two radiologists and two pathologists, respectively. Clinical and laboratory data for each patient were obtained from the electronic medical records, when available. RESULTS: All 11 patients had a CT prior to resection or biopsy of the adrenal nodule, with five having received an adrenal mass protocol study. An MRI was available in three patients. The median size of the nodules on imaging was 4.5 cm (range 2.8-8.7) and all but one had macroscopic fat. The largest focus of macroscopic fat had a median size of 0.7 cm (range 0.2-1.6) and on average was 14.4% the size of the tumor, using greatest dimensions. Four (36.4%) patients had a diagnosis of Cushing syndrome prior to nodule resection. CONCLUSIONS: Not all adrenal nodules with macroscopic fat on imaging are pure myelolipomas. An AMD should be considered, especially if the foci of fat are small and other features of an adenoma are present. Some may also be associated with Cushing syndrome. ADVANCES IN KNOWLEDGE: Myelolipomatous degeneration within an adrenal adenoma has only rarely been previously reported with very few reports emphasizing the imaging features. There may be an association with cortisol hypersecretion and improved recognition of this entity could lead to changes in clinical management.

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.

Incidentally discovered myelolipomatous adrenal adenomas, including six cases presenting with hypercortisolism.

Most adrenal incidentalomas are non-functioning adenomas that require no treatment. The presence of a myelolipomatous component of adrenal incidentalomas is a rare, but well-known occurrence in both hyperplastic and neoplastic lesions of the adrenal cortex. Although the improvements in abdominal imaging have increased identification of myelolipomatous adrenal cortical adenomas radiologically, due to the rarity of this lesion, the clinical pathological features of these lesions are unclear and can sometimes cause diagnostic difficulty. Eleven patients had surgeries at The University of Texas MD Anderson Cancer Center. Four additional cases were provided from an external collaborator. Of the 15 cases, there were 5 male and 10 female patients, with a median age of 52 years (mean 54 years, range 28-84 years). Clinical presentation included adrenal incidentaloma (n = 9), Cushing syndrome (n = 4, including 1 as a part of Carney complex), and subclinical Cushing syndrome (n = 2, including 1 with bilateral macronodular adrenal hyperplasia). In this study, we present the clinicopathologic features of fifteen myelolipomatous adrenal adenomas, the largest series published thus far.

Current Concepts in Multi-Modality Imaging of Solid Tumor Angiogenesis.

There have been rapid advancements in cancer treatment in recent years, including targeted molecular therapy and the emergence of anti-angiogenic agents, which necessitate the need to quickly and accurately assess treatment response. The ideal tool is robust and non-invasive so that the treatment can be rapidly adjusted or discontinued based on efficacy. Since targeted therapies primarily affect tumor angiogenesis, morphological assessment based on tumor size alone may be insufficient, and other imaging modalities and features may be more helpful in assessing response. This review aims to discuss the biological principles of tumor angiogenesis and the multi-modality imaging evaluation of anti-angiogenic therapeutic responses.

Coronavirus Disease 2019 (COVID-19)-Associated Thromboembolic Disease: A Report of Three Patients With Pulmonary Embolism.

Coagulopathy and thromboembolic disease, including pulmonary embolism (PE), are reported complications of coronavirus disease 2019 (COVID-19). The mechanism is not fully understood. We present three patients with COVID-19 and concurrent PE.