The 2021 World Health Organization Central Nervous System Tumor Classification: The Spectrum of Diffuse Gliomas.

The 2021 edition of the World Health Organization (WHO) classification of central nervous system tumors introduces significant revisions across various tumor types. These updates, encompassing changes in diagnostic techniques, genomic integration, terminology, and grading, are crucial for radiologists, who play a critical role in interpreting brain tumor imaging. Such changes impact the diagnosis and management of nearly all central nervous system tumor categories, including the reclassification, addition, and removal of specific tumor entities. Given their pivotal role in patient care, radiologists must remain conversant with these revisions to effectively contribute to multidisciplinary tumor boards and collaborate with peers in neuro-oncology, neurosurgery, radiation oncology, and neuropathology. This knowledge is essential not only for accurate diagnosis and staging, but also for understanding the molecular and genetic underpinnings of tumors, which can influence treatment decisions and prognostication. This review, therefore, focuses on the most pertinent updates concerning the classification of adult diffuse gliomas, highlighting the aspects most relevant to radiological practice. Emphasis is placed on the implications of new genetic information on tumor behavior and imaging findings, providing necessary tools to stay abreast of advancements in the field. This comprehensive overview aims to enhance the radiologist's ability to integrate new WHO classification criteria into everyday practice, ultimately improving patient outcomes through informed and precise imaging assessments.

Population-based estimates suggest middle meningeal artery embolization for subdural hematomas could significantly expand the scope of neurovascular therapies.

BACKGROUND: This study quantifies the impact of middle meningeal artery embolization (MMAE) for subdural hematomas (SDHs) by estimating a target population. METHODS: A population-based study at a tertiary hospital, the main SDH facility for a four-county population, used primary ICD-10 codes over 3 years to collate SDH hospitalizations. Clinical and imaging data confirmed traumatic versus non-traumatic and acute versus non-acute (mixed or chronic) SDH. The MMAE-eligible population included patients with non-traumatic, non-acute SDH aged ≥18 years plus patients with 'traumatic' but non-acute SDH aged ≥60 years presenting with a fall. This was contrasted with the rate of large vessel strokes in the same population. RESULTS: 1279 hospitalizations with a primary ICD-10 SDH diagnosis were identified, with 389 from the study population. Excluding repeat admissions, 350 patients were analyzed, 233 (67%) traumatic, and 117 (33%) non-traumatic SDH. Regarding etiology, 'fall ≥60 years' was the most common category in the entire cohort (n=156; 45% (95% CI 39% to 50%)). The SDH rate was 52/100 000 persons/year (95% CI 47 to 57). The rate of all non-traumatic, non-acute SDH in patients aged ≥18 years was 17/100 000 persons/year (95% CI 15 to 20), combining with 'traumatic' but non-acute fall-related SDH in patients aged ≥60 years yielded 41/100 000 persons/year (95% CI 36 to 47). This demographic may represent an MMAE-eligible population, exceeding large vessel stroke rates (31/100 000 persons/year) in the same population, estimating 139 387 potential MMAE cases/year (95% CI 121 517 to 158 168) in the USA. CONCLUSION: MMAE could transform non-acute SDH management, especially in the elderly, potentially surpassing the impact of large vessel stroke. Clinical trials are essential for validation of its efficacy and safety compared with standard management.

Prolonged venous transit on perfusion imaging is associated with higher odds of mortality in successfully reperfused patients with large vessel occlusion stroke.

BACKGROUND: Poor venous outflow (VO) profiles are associated with unfavorable outcomes in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO), despite achieving successful reperfusion. The objective of this study is to assess the association between mortality and prolonged venous transit (PVT), a novel visual qualitative VO marker on CT perfusion (CTP) time to maximum (Tmax) maps. METHODS: We performed a retrospective analysis of prospectively collected data from consecutive adult patients with AIS-LVO with successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b/2c/3). PVT+ was defined as Tmax ≥10 s timing on CTP Tmax maps in at least one of the following: superior sagittal sinus (proximal venous drainage) and/or torcula (deep venous drainage). PVT- was defined as lacking this in both regions. The primary outcome was mortality at 90 days. In a 1:1 propensity score-matched cohort, regressions were performed to determine the effect of PVT on 90-day mortality. RESULTS: In 127 patients of median (IQR) age 71 (64-81) years, mortality occurred in a significantly greater proportion of PVT+ patients than PVT- patients (32.5% vs 12.6%, P=0.01). This significant difference persisted after matching (P=0.03). PVT+ was associated with a significantly increased likelihood of 90-day mortality (OR 1.22 (95% CI 1.02 to 1.46), P=0.03) in the matched cohort. CONCLUSIONS: PVT+ was significantly associated with 90-day mortality despite successful reperfusion therapy in patients with AIS-LVO. PVT is a simple VO profile marker with potential as an adjunctive metric during acute evaluation of AIS-LVO patients. Future studies will expand our understanding of using PVT in the evaluation of patients with AIS-LVO.

Infectious Diseases of the Brain and Spine: Parasitic and Other Atypical Transmissible Diseases.

Atypical infections of the brain and spine caused by parasites occur in immunocompetent and immunosuppressed hosts, related to exposure and more prevalently in endemic regions. In the United States, the most common parasitic infections that lead to central nervous system manifestations include cysticercosis, echinococcosis, and toxoplasmosis, with toxoplasmosis being the most common opportunistic infection affecting patients with advanced HIV/AIDS. Another rare but devastating transmittable disease is prion disease, which causes rapidly progressive spongiform encephalopathies. Familiarity and understanding of various infectious agents are a crucial aspect of diagnostic neuroradiology, and recognition of unique features can aid timely diagnosis and treatment.

Infectious Diseases of the Brain and Spine: Fungal Diseases.

Advances in treatments of autoimmune diseases, acquired immunodeficiency syndrome, organ transplantation, and the use of long-term devices have increased the rates of atypical infections due to prolonged immune suppression. There is a significant overlap in imaging findings of various fungal infections affecting the central nervous system (CNS), often mimicking those seen in neoplastic and noninfectious inflammatory conditions. Nonetheless, there are imaging characteristics that can aid in distinguishing certain atypical infections. Hence, familiarity with a wide range of infectious agents is an important part of diagnostic neuroradiology. In this article, an in-depth review of fungal diseases of the CNS is provided.

Current State of Functional MRI in the Presurgical Planning of Brain Tumors.

Surgical resection of brain tumors is challenging because of the delicate balance between maximizing tumor removal and preserving vital brain functions. Functional MRI (fMRI) offers noninvasive preoperative mapping of widely distributed brain areas and is increasingly used in presurgical functional mapping. However, its impact on survival and functional outcomes is still not well-supported by evidence. Task-based fMRI (tb-fMRI) maps blood oxygen level-dependent (BOLD) signal changes during specific tasks, while resting-state fMRI (rs-fMRI) examines spontaneous brain activity. rs-fMRI may be useful for patients who cannot perform tasks, but its reliability is affected by tumor-induced changes, challenges in data processing, and noise. Validation studies comparing fMRI with direct cortical stimulation (DCS) show variable concordance, particularly for cognitive functions such as language; however, concordance for tb-fMRI is generally greater than that for rs-fMRI. Preoperative fMRI, in combination with MRI tractography and intraoperative DCS, may result in improved survival and extent of resection and reduced functional deficits. fMRI has the potential to guide surgical planning and help identify targets for intraoperative mapping, but there is currently limited prospective evidence of its impact on patient outcomes. This review describes the current state of fMRI for preoperative assessment in patients undergoing brain tumor resection. Keywords: MR-Functional Imaging, CNS, Brain/Brain Stem, Anatomy, Oncology, Functional MRI, Functional Anatomy, Task-based, Resting State, Surgical Planning, Brain Tumor © RSNA, 2023.

Facial nerve schwannoma: Case report and brief review of the literature.

Schwannomas are rare nerve sheath tumors that can occur throughout the body, and are symptomatic based on location, size, and impingement on adjacent structures. These tumors are often benign lesions and occur sporadically or from genetic conditions such as neurofibromatosis. Schwannomas may arise from peripheral nerves, gastrointestinal nerves, spinal nerve roots and cranial nerves. Facial nerve schwannomas arise from cranial nerve VII, commonly involving the geniculate ganglion, labyrinthine segment, and internal auditory canal. While small lesions are asymptomatic, larger lesions can cause facial nerve paralysis, and facial spasms. Lesions in the internal auditory canal can cause hearing loss, tinnitus, vertigo, and otalgia. High-resolution CT imaging and MRI imaging are useful for distinguishing between other pathologies that arise from the same region. High-resolution CT scans can show bony degeneration of nearby structures such as the labyrinth or ossicles. MRI imaging shows hypo intensity on T1 imaging, and hyperintensity on T2 imaging. On T1 postcontrast, enhancement can be homogenous or heterogeneous with cystic degeneration if the lesion is large. Nodular enhancement is commonly seen on facial nerve schwannomas within the internal auditory canal. Vestibular schwannomas involving CN VIII are more common, and appear similar to facial nerve schwannomas, but can be distinguished apart due to growth in the geniculate ganglion and/or the labyrinthine segment. Management of asymptomatic or mild lesions is typically conservative with follow up imaging, and surgery for larger lesions. Here, we present a case of a facial nerve schwannoma in a 57-year-old woman.

Longitudinal lung cancer prediction convolutional neural network model improves the classification of indeterminate pulmonary nodules.

A deep learning model (LCP CNN) for the stratification of indeterminate pulmonary nodules (IPNs) demonstrated better discrimination than commonly used clinical prediction models. However, the LCP CNN score is based on a single timepoint that ignores longitudinal information when prior imaging studies are available. Clinically, IPNs are often followed over time and temporal trends in nodule size or morphology inform management. In this study we investigated whether the change in LCP CNN scores over time was different between benign and malignant nodules. This study used a prospective-specimen collection, retrospective-blinded-evaluation (PRoBE) design. Subjects with incidentally or screening detected IPNs 6-30 mm in diameter with at least 3 consecutive CT scans prior to diagnosis (slice thickness ≤ 1.5 mm) with the same nodule present were included. Disease outcome was adjudicated by biopsy-proven malignancy, biopsy-proven benign disease and absence of growth on at least 2-year imaging follow-up. Lung nodules were analyzed using the Optellum LCP CNN model. Investigators performing image analysis were blinded to all clinical data. The LCP CNN score was determined for 48 benign and 32 malignant nodules. There was no significant difference in the initial LCP CNN score between benign and malignant nodules. Overall, the LCP CNN scores of benign nodules remained relatively stable over time while that of malignant nodules continued to increase over time. The difference in these two trends was statistically significant. We also developed a joint model that incorporates longitudinal LCP CNN scores to predict future probability of cancer. Malignant and benign nodules appear to have distinctive trends in LCP CNN score over time. This suggests that longitudinal modeling may improve radiomic prediction of lung cancer over current models. Additional studies are needed to validate these early findings.

Distal cholangiocarcinoma: case report and brief review of the literature.

Adenocarcinomas of the distal bile duct are traditionally classified as either pancreatobiliary or intestinal type, with pancreatic adenocarcinoma and cholangiocarcinoma included within the former classification. Cholangiocarcinoma is a rare and deadly malignancy that occurs within three clinically defined regions: intrahepatic, perihilar, and in the distal bile duct. We present a 68-year-old male with a past medical history of human immunodeficiency virus, hepatitis B, hypertension, and hyperlipidemia who presented to the emergency department with a 3-week history of diarrhea, diffuse abdominal pain, malaise, and nausea. Contrast enhanced CT of the abdomen and pelvis revealed a periampullary mass. Endoscopic ultrasound biopsy was performed, with histopathology suggestive of distal cholangiocarcinoma. Endoscopic retrograde cholangiopancreatography was utilized for palliative stent placement until patient received pancreaticoduodenectomy (ie, Whipple procedure). In this case, we highlight the imaging presentation and histopathology of a distal cholangiocarcinoma.

Prostatic adenocarcinoma in a patient with persistent Müllerian duct syndrome.

The embryonal male sexual differentiation is driven by testosterone, and Anti-Müllerian hormone (AMH). AMH is responsible for regression of Müllerian ducts in a genetically male fetus. Mutations inactivating AMH or its receptors are responsible for persistent Müllerian duct syndrome (PMDS) in virilized 46, XY males. PMDS is a rare genetic disorder affecting males, with less than 300 cases described in literature. The syndrome is usually recognized early in life with patients present with bilateral undescended testicles, and often decreased testosterone production by Leydig cells later in life. The role of testosterone in the development and progression of prostate cancer is well established, and men with low circulating free testosterone are expected to have a lower risk of developing prostate cancer. Indeed, 2 cases of prostate cancer in patients with PMDS have previously been described. Herein, we are reporting the third of prostate cancer in patient with PMDS.

Giant mediastinal bronchial artery aneurysm mimicking mediastinal mass: A case report and brief review of the literature.

Bronchial artery aneurysm and pseudoaneurysm is a rare but life-threatening diagnosis due to catastrophic complications from rupture. Prompt detection and management is key to prevent complications. CT angiogram and digital subtraction angiography are preferred diagnostic imaging modalities. Being very uncommon, these entities can be misdiagnosed as a nonspecific mediastinal soft tissue mass, which can lead to delay in diagnosis and inappropriate or delayed management. We present a case of 72-year-old woman with incidentally detected large bronchial artery pseudoaneurysm, incorrectly classified as mediastinal malignancy at outside facility, receiving follow-up exams for 2 years, before correct diagnosis and management.

Congenital adrenal hyperplasia with associated giant adrenal myelolipoma, testicular adrenal rest tumors and primary pigmented nodular adrenocortical disease: A case report and brief review of the literature.

Congenital adrenal hyperplasia is an autosomal recessive disease most commonly associated with 21-hydroxylase deficiency, an enzyme integral in the biosynthesis of mineralocorticoids and glucocorticoids. We present a case of a 49-year-old male with congenital adrenal hyperplasia and commonly associated findings of adrenal myelolipoma, testicular adrenal rest tumors, as well as primary pigmented nodular adrenocortical disease. Adrenal myelolipoma is a rare, benign disease process associated with exogenous steroid treatment noncompliance in the setting of congenital adrenal hyperplasia. Testicular adrenal rest tumors are benign testicular tumors associated with congenital adrenal hyperplasia. Primary pigmented nodular adrenocortical disease is an ACTH-independent cortisol producing lesion. Our case emphasizes the association of congenital adrenal hyperplasia with adrenal myelolipoma and testicular adrenal rest tumors as well as the importance of familiarity with these associations to guide patient management.

Photorealistic Depiction of Intracranial Tumors Using Cinematic Rendering of Volumetric 3T MRI Data.

RATIONALE AND OBJECTIVES: Cinematic Rendering (CR) incorporates a complex lightning model that creates photorealistic models from isotropic 3D imaging data. The utility of CR in depicting volumetric MRI data for pre-therapeutic planning is discussed, with intracranial tumors as a demonstrative example. MATERIALS AND METHODS: We present a series of Cinematically Rendered intracranial tumors and discuss their utility in multidisciplinary pre-therapeutic evaluation. Isotropic, high-resolution, volumetric MRI data was collected, and CR was performed utilizing a proprietary application, "Anatomy Education" Siemens, Munich, Germany. RESULTS: Discrimination of cortex to white matter, brain surface to vessels, subarachnoid space to cortex and skull to intracranial structures was achieved and optimized by using various display settings on the Anatomy education application. Progressive removal of tissue layers allowed for a comprehensive assessment of the entire region of interest. Complex, small structures were demonstrated in very high detail. The depth and architecture of the sulci was appreciated in a format that more closely mimicked gross pathology than traditional imaging modalities. With appropriate display settings, the relationship of the cortical surface to the adjacent vasculature was also delineated. CONCLUSION: CR depicts the anatomic location of brain tumors in a format that depicts the relative proximity of adjacent structures in all dimensions and degrees of freedom. This allows for better conceptualization of the pathology and greater ease of communication between radiologists and other clinical teams, especially in the context of pretherapeutic planning.

Primary nodular chest amyloidoma: A case report and review of literature.

Primary nodular chest wall amyloidoma, in which a solitary mass of amyloid is deposited in and around the lungs with no evidence of systemic amyloidosis, is extremely rare, most often asymptomatic, and may resemble primary bronchogenic carcinoma. As a result, there are fewer than 100 cases published in the literature and no controlled clinical trials. Primary nodular chest wall amyloidoma is typically diagnosed either as an incidental radiological finding or after very serious and destructive mass growth at which point late-stage respiratory and pain symptoms finally develop, most often in elderly patients. We present imaging studies of a 61-year-old male patient with an unusually massive and destructive chest wall mass, originating in the chest wall, diagnosed as chest wall amyloidoma by histopathology analysis. Our CT, MRI, and PET scan findings are consistent with and contribute to the developing pattern of imaging characteristics seen in other case studies, which can be used to identify amyloidoma before it becomes destructive using non-invasive imaging analyses.

Prominent crista terminalis mimicking a right atrial mass: A case report and brief review of the literature.

The crista terminalis is a normal anatomical structure, characterized by a smooth muscular ridge along the superior aspect of the right atrium. It is derived from resorption of the right valve of the sinus venosus and it divides the right atrium into smooth posteromedial and trabeculated anterolateral portions. Crista terminalis is not normally detected in the standard views of transthoracic echocardiogram and non-gated CT of the chest. In rare circumstances, the crista terminalis may be prominent and could lead to misdiagnosis as a malignant process, such as in our case. A comprehensive understanding of the crista terminalis anatomy, and its characteristic appearance on transthoracic echocardiogram, CT and PET/CT will minimize the risk of misdiagnosis and will avoid patient anxiety with more extensive examinations. Here, we present a case of a 78-year-old male with newly diagnosed high-grade invasive urinary bladder urothelial carcinoma. Pre-operative transthoracic echocardiogram reported as 2 cm right atrial mass concerning a metastasis lesion. Subsequent evaluation with MRI cardiac morphology confirmed the diagnosis of benign prominent crista terminalis, a normal anatomical structure.