Comparative analysis of brain language templates with primary language areas detected from presurgical fMRI of brain tumor patients.

INTRODUCTION: Functional brain templates are often used in the analysis of clinical functional MRI (fMRI) studies. However, these templates are mostly built based on anatomy or fMRI of healthy subjects, which have not been fully vetted in clinical cohorts. Our aim was to evaluate language templates by comparing with primary language areas (PLAs) detected from presurgical fMRI of brain tumor patients. METHODS: Four language templates (A-D) based on anatomy, task-based fMRI, resting-state fMRI, and meta-analysis, respectively, were compared with PLAs detected by fMRI with word generation and sentence completion paradigms. For each template, the fraction of PLA activations enclosed by the template (positive inclusion fraction, [PIF]), the fraction of activations within the template but that did not belong to PLAs (false inclusion fraction, [FIF]), and their Dice similarity coefficient (DSC) with PLA activations were calculated. RESULTS: For anterior PLAs, Template A had the greatest PIF (median, 0.95), whereas Template D had both the lowest FIF (median, 0.074), and the highest DSC (median, 0.30), which were all significant compared to other templates. For posterior PLAs, Templates B and D had similar PIF (median, 0.91 and 0.90, respectively) and DSC (both medians, 0.059), which were all significantly higher than that of Template C. Templates B and C had significantly lower FIF (median, 0.061 and 0.054, respectively) compared to Template D. CONCLUSION: This study demonstrated significant differences between language templates in their inclusiveness of and spatial agreement with the PLAs detected in the presurgical fMRI of the patient cohort. These findings may help guide the selection of language templates tailored to their applications in clinical fMRI studies.

Probabilistic Presurgical Language Functional MRI Atlas of Brain Tumor Patients.

BACKGROUND AND PURPOSE: Patients with brain tumors have high intersubject variation in putative language regions, which may limit the utility of straightforward application of healthy-subject brain atlases in clinical scenarios. The purpose of this study was to develop a probabilistic functional brain atlas that consolidates language functional activations of sentence completion and silent word generation language paradigms using a large sample of patients with brain tumors. MATERIALS AND METHODS: The atlas was developed using retrospectively collected fMRI data from patients with brain tumors who underwent their first standard-of-care presurgical language fMRI scan at our institution between July 18, 2015, and May 13, 2022. 317 patients (861 fMRI scans) were used to develop the language functional atlas. An independent presurgical language fMRI dataset of 39 patients with brain tumors from a previous study was used to evaluate our atlas. Family-wise error corrected binary functional activation maps from sentence completion, letter fluency, and category fluency presurgical fMRI were used to create probability overlap maps and pooled probabilistic overlap map in Montreal Neurological Institute standard space. Wilcoxon signed-rank test was used to determine significant difference in the maximum Dice coefficient for our atlas compared to a meta-analysis-based template with respect to expert-delineated primary language area activations. RESULTS: Probabilities of activating left anterior primary language area and left posterior primary language area in temporal lobe were 87.9% and 91.5%, respectively, for sentence completion, 88.5% and 74.2%, respectively, for letter fluency, and 83.6% and 67.6%, respectively, for category fluency. Maximum Dice coefficients for templates derived from our language atlas were significantly higher than the meta-analysis-based template in left anterior primary language area (0.351 and 0.326, respectively, P < .05) and left posterior primary language area in temporal lobe (0.274 and 0.244, respectively, P < .005). CONCLUSIONS: Brain tumor patient-and paradigm-specific probabilistic language atlases were developed. These atlases had superior spatial agreement with fMRI activations in individual patients than the meta-analysis-based template. ABBREVIATIONS: SENT = sentence completion, LETT = letter fluency, CAT = category fluency, PLA = primary language area, aPLA = anterior PLA, pPLAT = posterior PLA in the temporal lobe, pPLAP = posterior PLA in the parietal lobe, SMA = supplementary motor area, DLPFC = dorsolateral prefrontal cortex, BTLA = basal temporal language area.

Imaging Features of Primary Intracranial Sarcoma with DICER1 Mutation: A Multicenter Case Series.

Primary intracranial sarcoma, DICER1-mutant, is a rare, recently described entity in the fifth edition of the WHO Classification of CNS Tumors. Given the entity's rarity and recent description, imaging data on primary intracranial sarcoma, DICER1-mutant, remains scarce. In this multicenter case series, we present detailed multimodality imaging features of primary intracranial sarcoma, DICER1-mutant, with emphasis on the appearance of the entity on MR imaging. In total, 8 patients were included. In all 8 patients, the lesion demonstrated blood products on T1WI. In 7 patients, susceptibility-weighted imaging was obtained and demonstrated blood products. Primary intracranial sarcoma, DICER1-mutant, is a CNS neoplasm that primarily affects pediatric and young adult patients. In the present case series, we explore potential imaging findings that are helpful in suggesting this diagnosis. In younger patients, the presence of a cortical lesion with intralesional blood products on SWI and T1-weighted MR imaging, with or without extra-axial blood products, should prompt the inclusion of this entity in the differential diagnosis.

Parathyroid carcinoma: Imaging features of initial presentation and recurrence. A single center experience.

BACKGROUND AND PURPOSE: Parathyroid carcinoma is the rarest endocrine neoplasm with very few published data discussing its imaging appearance with primary focus on ultrasound imaging features. We present our 23 years institutional experience to highlight multimodality imaging evaluation at presentation and at recurrence. MATERIAL AND METHODS: Retrospective chart review of clinical and pathological diagnosis of parathyroid carcinoma patients presented for initial or recurrent disease management at M.D. Anderson Cancer Center between the period of January 2000 and February 2023 was performed. Imaging findings on US, CT, PET/CT, and technetium-99m sestamibi were analyzed for initial and local recurrent parathyroid carcinoma. We further assess patterns of distant recurrence and its location. RESULTS: Twenty three patients with pathological and clinical diagnosis of initial (14 patients) or recurrent parathyroid carcinoma (14 patients) were included in this study. US findings of parathyroid carcinoma were larger lesions, increased/irregular vascularity, and non-circumscribed margins. Multiphasic CT findings of parathyroid carcinoma included an arterially enhancing lesion that is hypoenhancing relative to the thyroid and demonstrates no washout on delayed imaging. Highly suggestive findings for recurrent disease included a hypoechoic solid nodule (91.67%) with increased vascularity on ultrasound (81.8%) with corresponding enhancement on CT. CONCLUSION: Parathyroid carcinoma is a rare malignancy often diagnosed after surgical resection. We provided CT and US imaging features that are helpful in suggesting the diagnosis of parathyroid carcinoma and detection of early local recurrence.

Good Gone Bad: Complications of Chemotherapy, Immunotherapy, and Radiotherapy on the CNS.

With recent advancements in cancer therapy, especially immunotherapy, overall survival of many cancers has increased and patient toxicity has been reduced. However, many complications of traditional cancer therapy are still prevalent and complications of novel therapies are just beginning to appear. The neuroradiologist may be the first to visualize signs of these complications on imaging. This article describes the notable imaging findings of several unique and characteristic complications of CNS cancer therapy, including toxicities of chemotherapies, immunotherapies, and radiotherapy. Complications of chemotherapeutic agents covered include methotrexate-induced and disseminated necrotizing leukoencephalopathy, and chemotherapy-induced myelopathy. Immunotherapy complications included are Tacrolimus-related Optic Neuropathy, Rituximab and Immune reconstitution inflammatory syndrome-associated Progressive Multifocal Leukoencephalopathy, Bevacizumab-associated late radiation-induced neurotoxicity, and Ipilimumab-induced hypophysitis. Lastly, radiation-induced neurotoxicities are covered, including myelopathy, radiation necrosis, cerebral atrophy, leukoencephalopathy, optic neuropathy, mineralizing microangiopathy, stroke-like migraine attacks, osteonecrosis, and vasculopathies. Neuroradiologists will increasingly encounter patients who have undergone treatment with more than 1 therapeutic modality, resulting in overlapping findings as well. Recognition of the common complications of these therapies on imaging is critical to minimizing the effects of these potential short- and long-term complications.

Head and Neck Sarcoma Tumor Board Survival Guide for Neuroradiologists: Imaging Findings, History, and Pathology.

Sarcomas of the head and neck carry a poor prognosis as diagnosis is often delayed until a late stage of the disease. Accordingly, it is essential to be familiar with the clinical and imaging features of sarcomas to suggest an appropriate differential diagnosis for collaborating surgeons and pathologists. However, as there are only 1000-1500 cases in the United States annually, many radiologists lack experience with pertinent imaging findings of sarcoma and lack knowledge of both treatment and necessary follow-up. In this review, a brief discussion of WHO definitions and histopathology is included to decode information provided by pathologists. Finally, staging and treatments are illuminated to aid the radiologist with initial imaging staging and follow-up care. This review aims to increase the comprehensive knowledge of a neuroradiologist and further their value to the multidisciplinary tumor board.

Delineation of Inner Annulus Fibrosus and Nucleus Pulposus on Routine T2-weighted MR Images.

STUDY DESIGN: Retrospective study of 150 IVDs. OBJECTIVE: Assessment of costume algorithm ability to delineate the IAF and NP on routine T2 images. SUMMARY OF BACKGROUND DATA: Central hyperintense region on T2-weighted MR images of normal lumbar IVDs represents a combination of IAF and NP. Ability to identify NP as distinct from IAF can help improve our understanding of IVD morphology in-vivo. METHODS: Sagittal T2-weighted TSE MR images of 150 lumbar IVDs from 25 patients were analyzed. MR images were processed using a custom algorithm that markedly increased the signal intensity of structures with inherent signal intensity within 2 defined intensity thresholds. Signal intensity and contrast-to- noise ratio between outer annulus fibrosus, IAF, and NP were assessed at baseline and after processing. To assess consistency of underlying T2 differences, similar analysis was done on 108 discs from 18 patients in whom additional sagittal T2-weighted STIR images were available. RESULTS: Following image processing, apparent IAF and NP were rendered visible in 86% and 84.3% IVDs on T2-weighted TSE and STIR images respectively. While signal intensity of these 2 regions was inherently different (P< 0.001) before processing on TSE and STIR images, their visualization was facilitated by a significant increase (P<0.001) in contrast-to-noise ratio after processing. Nonvisualization of NP was associated with disc degeneration (P<0.001). CONCLUSION: Inherent differences exist in signal intensities of normal NP and IAF on T2-weighted MR images. Accentuating these differences using image postprocessing techniques can render these 2 structures visible.

Performance of Automated RAPID Intracranial Hemorrhage Detection in Real-World Practice: A Single-Institution Experience.

BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is a common finding in patients presenting to the emergency department with acute neurological symptoms. Noncontrast head computed tomography (NCCT) is the primary modality for assessment and detection of ICH in the acute setting. RAPID ICH software aims to automatically detect ICH on NCCT and was previously shown to have high accuracy when applied to a curated test data set. Here, we measured the test performance characteristics of RAPID ICH software in detecting ICH on NCCT performed in patients undergoing emergency stroke evaluation at a tertiary academic comprehensive stroke center. MATERIALS AND METHODS: This retrospective study assessed consecutive patients over a 6-month period who presented with acute neurological symptoms suspicious for stroke and underwent NCCT with RAPID ICH postprocessing. RAPID ICH detection was compared with the interpretation of a reference standard comprising a board-certified or board-eligible neuroradiologist, or in cases of discrepancy, adjudicated by a consensus panel of 3 neuroradiologists. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RAPID ICH for ICH detection were determined. RESULTS: Three hundred seven NCCT scans were included in the study. RAPID ICH correctly identified 34 of 37 cases with ICH and 228 of 270 without ICH. RAPID ICH had a sensitivity of 91.9% (78.1%-98.3%), specificity of 84.4% (79.6%-88.6%), NPV of 98.7% (96.3%-99.6%), PPV of 44.7% (37.6%-52.1%), and overall accuracy of 85.3% (80.9%-89.1%). CONCLUSIONS: In a real-world scenario, RAPID ICH software demonstrated high NPV but low PPV for the presence of ICH when evaluating possible stroke patients.

External Ear Diseases: A Comprehensive Review of the Pathologies With Neuroradiological Considerations.

The peripheral auditory system is subdivided into 3 compartments: the external, middle, and inner ear. Historically, the middle and inner ear have garnered more attention in the imaging literature, due to their intricate anatomy and complexity of pathologies. The external ear, however, has attained less recognition given its relatively straightforward anatomy and convenience of direct visual examination. The continued advancement in computed tomography and magnetic resonance imaging has expanded the role of radiology in the evaluation of the external ear lesions. The purpose of this article is to offer a comprehensive review of external ear pathologies, including congenital, inflammatory, infectious, traumatic, neoplastic, and rare disease entities and their imaging findings.

The Forgotten Phacomatoses: A Neuroimaging Review of Rare Neurocutaneous Disorders.

Phakomatoses, or neurocutaneous syndromes, are a heterogeneous group of rare genetic disorders that predominantly affect structures arising from the embryonic ectoderm, namely the skin, eye globe, retina, tooth enamel, and central nervous system. Other organs are also involved in some syndromes, mainly cardiovascular, pulmonary, renal, and musculoskeletal systems. Currently, more than sixty distinct entities belonging to this category have been described in the literature. Common phakomatoses include conditions like Neurofibromatosis and Tuberous sclerosis. Several review papers have focused on various aspects of these common conditions, including clinical presentation, genetic and molecular basis, and neuroimaging features. In this review, we focus on rare neurocutaneous syndromes: Melanophakomatoses (Ie, Neurocutaneous Melanosis, and Incontinentia Pigmenti), Vascular Phakomatoses (Ie, Ataxia Telangiectasia and PHACE Syndrome), and other conditions such as Cowden Syndrome, Basal Nevus Syndrome, Schwannomatosis, Progressive Facial Hemiatrophy, Gomez-Lopez-Hernandez Syndrome, Wyburn-Mason Syndrome, CHILD Syndrome, and Proteus Syndrome. We also review the neuroradiologic manifestations of these conditions as a guide for neurologists and neuroradiologists in their daily practice.

Novel radiographic presentation of primary syphilis of the tonsil.

A 61-year-old HIV+ male presented to an infectious disease clinic with a complaint of sore throat. A painless ulcerated mass was discovered on the right tonsil resulting in further evaluation with a CT scan of the neck. Imaging confirmed the presence of a mass centered on the palatine tonsil and associated lymphadenopathy. A presumptive diagnosis of HPV-related squamous cell carcinoma was made due to patient risk factors. However, multiple biopsies found no evidence of carcinoma, but instead revealed the presence of spirochetes that stained positive for T Pallidum. Soon after, the patient developed the characteristic copper-red maculopapular rash of secondary syphilis, indicating that the tonsillar mass was, in fact, a primary chancre. Since such chancres are most often found externally in the genital or anal region, they are seldom radiographically characterized, placing them low on the differential diagnosis for most radiologists. A high index of suspicion could aid future radiologists in placing primary syphilis higher on the differential diagnosis in similar cases in which the patient has appropriate risk factors, such as a known history of genital-oral sexually transmitted infections or an immunocompromised state. Prompt recognition of the nature of a primary syphilitic lesion can lead to rapid resolution of symptoms following treatment with intramuscular benzathine penicillin G, as eventually occurred in this case.

Computed Tomography as a Predictor of Sinonasal Inverted Papilloma Origin, Skull Base Involvement, and Stage.

Objective To investigate the diagnostic performance of computed tomography (CT) to determine the origin, skull base involvement, and stage of sinonasal inverted papilloma (IP). Design This is a retrospective cohort study. Setting This is set at a tertiary care medical center. Participants Patients with preoperative CT imaging who underwent extirpative surgery for histologically confirmed sinonasal IP between January 2005 and October 2019. Main Outcome Measures The likely sites of tumor origin, skull base involvement, and radiographic tumor stage were determined by two board-certified neuroradiologists after re-reviewing preoperative CT imaging. These radiologic findings were then compared with intraoperative and pathologic findings. Results Of 86 patients, 74% (64/86) had IP lesions with correctly classified sites of origin on CT. CT was not sensitive for diagnosing ethmoid sinus origin (48%, 52%), frontal sinus origin (80%, 40%), and skull base origin (17%, 17%). CT was not sensitive (62%, 57%) but specific (86%, 98%) for identifying any skull base involvement. There was substantial-to-near perfect agreement between radiographic and pathologic Cannady stages (weighted κ = 0.61 for rater 1; weighted κ = 0.81 for rater 2). Interrater agreement was substantial for identifying tumor origin (κ = 0.75) and stage (weighted κ = 0.62) and moderate for identifying skull base involvement (κ = 0.43). Conclusion Interrater agreement on CT findings was substantial except on skull base involvement. CT correctly predicted site of tumor origin in up to 74% of subjects. CT was not sensitive for diagnosing skull base involvement but had substantial-to-near perfect agreement with pathologic tumor staging. CT is a useful but albeit limited adjunct for tumor localization and surgical planning for sinonasal IP.

Evaluating the effect of a post-processing algorithm in detection of annular fissure on MR imaging.

BACKGROUND AND PURPOSE: Visualization of annular fissures on MRI is becoming increasingly important but remains challenging. Our purpose was to test whether an image processing algorithm could improve detection of annular fissures. MATERIALS AND METHODS: In this retrospective study, two neuroradiologists identified 56 IVDs with annular fissures and 97 IVDs with normal annulus fibrosus in lumbar spine MRIs of 101 patients (58 M, 43 F; age ± SD 15.1 ± 3.0 years). Signal intensities of diseased and normal annulus fibrosus, and contrast-to-noise ratio between them on sagittal T2-weighted images were calculated before and after processing with a proprietary software. Effect of processing on detection of annular fissures by two masked neuroradiologists was also studied for IVDs with Pfirrmann grades of ≤ 2 and > 2. RESULTS: Mean (SD) signal baseline intensities of diseased and normal annulus fibrosus were 57.6 (23.3) and 24.4 (7.8), respectively (p < 0.001). Processing increased (p < 0.001) the mean (SD) intensity of diseased annulus to 110.6 (47.9), without affecting the signal intensity of normal annulus (p = 0.14). Mean (SD) CNR between the diseased and normal annulus increased (p < 0.001) from 11.8 (14.1) to 29.6 (29.1). Both masked readers detected more annular fissures after processing in IVDs with Pfirrmann grade of ≤ 2 and > 2, with an apparent increased sensitivity and decreased specificity using predefined image-based human categorization as a reference standard. CONCLUSIONS: Image processing improved CNR of annular fissures and detection rate of annular fissures. However, further studies with a more stringent reference standard are needed to assess its effect on sensitivity and specificity.

Neuroimaging of Adult Lacrimal Drainage System.

The lacrimal drainage system (LDS) pathology is frequently encountered in the ophthalmology setting but is rarely discussed in the radiology literature. This is even truer for adult LDS lesions despite increase utilization of computed tomography and magnetic resonance in imaging for diagnosis of LDS pathology. The purpose of this image rich review is to highlight common adult LDS pathologies and introduce the radiologist to rare disease entities affecting this pathology rich anatomical region with emphasis on imaging findings, clinical presentation, and differential generation.

Ocular and brain imaging findings in Peters' anomaly: A case report and literature review.

Peters' anomaly is a rare congenital eye condition characterized by anterior segment dysgenesis and commonly presents as unilateral or bilateral corneal opacity in the early neonatal period. Peters' anomaly is often associated with congenital brain and skull abnormalities, which are frequently overlooked. In this paper, we present a case of a 5-day-old female neonate with Peters' anomaly, and review the literature for similar reports that describe associated brain imaging findings. In our case, imaging studies show abnormalities involving the anterior segments of both globes with absent intracranial manifestations. Although Peters' anomaly is a condition of interest for ophthalmologists, radiological studies should be performed, and neuroradiologists should be aware of the imaging findings associated with this rare entity.

Calvarial Langerhans cell histiocytosis in an Adult: Typical imaging findings in an atypical age group.

Langerhans Cell Histiocytosis (LCH) is a rare disorder characterized by neoplastic proliferation of Langerhans-type dendritic cells. LCH is most frequently encountered in the pediatric populations, and involvement of the skeletal system is a common manifestation. Herein, we report a case of LCH presented as an isolated skull lesion in a 66-year-old patient. This presentation has never been reported in the literature at this advanced age and suggests that, despite being exceptionally rare, clinicians should consider LCH in the differential diagnosis of skull lesions in the elderly with classical radiological appearance.