Diffuse Necrotizing Myelitis following Intracystic Bleomycin Chemotherapy for Craniopharyngioma

A child with recurrent adamantinomatous craniopharyngioma was treated with surgery and radiosurgery followed by 12 cycles of intracystic bleomycin injections. One month after treatment, he developed progressive lower extremity paresthesia, pain, wide-based gait, and urinary incontinence. MR imaging showed extensive T2 hyperintensity, enlargement, and enhancement extending from the medulla to the lower thoracic spinal cord. Spinal cord biopsy showed necrotizing myelitis. To our knowledge, this is the first histologically proven case of bleomycin spinal cord neurotoxicity.

Narrowing the Pipe: Different Etiologies of Tracheal Stenosis

The trachea serves as the conduit for passage of air between the larynx and the lung bronchi. The tracheal luminal caliber may be narrowed in adults by extrinsic mass effect from adjacent structures; intrinsic stenosis secondary to intubation, inflammatory, systemic, or idiopathic disorders; and benign or malignant masses. Contrast-enhanced CT accurately depicts the source of the stenosis and can measure the length and cross-sectional area of the stenosis and evaluate the extent of locoregional spread with malignancies. In addition, the data are capable of being reformatted by several techniques, including virtual endoscopy and surface-rendered reconstruction. Certain imaging characteristics such as the presence of calcifications and involvement or sparing of the posterior membrane can be useful to suggest a particular diagnosis or differential. Imaging, however, is not usually pathognomonic for a specific benign or malignant tracheal stenotic lesion, and ultimately biopsy is needed to establish a definitive histopathologic diagnosis.Learning Objective: To describe the different etiologies of tracheal stenosis

Twiglike MCA: A Not-So-Common Cerebral Vascular Anomaly

Congenital anomalies of the MCA are rare compared with the rest of the intracranial vasculature. An aplastic MCA, known as a twiglike MCA, is the result of replacement of MCA trunk by a plexiform network of small vessels. In this report, we aim to review the radiologic features of a twiglike MCA and its differential diagnosis, helping the reader differentiate this entity from more common pathologies to avoid unnecessary further investigation.

Raiders of the Lost Canal: Review of Underrecognized Skull Base Canals, Fissures, and Foramina

The anatomy of the skull base is complex and poses a daunting challenge to many radiologists and trainees. In addition to knowing major skull base passages, there are several underrecognized skull base canals, foramina, and fissures that are critical to avoid misdiagnosis, understand the spread of disease, and guide surgical management. A review of the current literature on these forgotten structures yielded numerous original articles and a few review articles, none of which were comprehensive. This article aimed to fill that void. We provide a comprehensive review of underrecognized skull base anatomic structures and their content and discuss their clinical implications.Learning Objective: Recognize uncommon skull base structures, their content, and their clinical implications

Multimodality Anatomic and Molecular Imaging of Parkinson Disease and Atypical Parkinson Syndromes with MRI, Iodine 123 N-ω-Fluoropropyl-2β-Carbomethoxy-3β-(4-Iodophenyl) Nortropane SPECT (Dopamine Transporter SPECT), Iodine 123 Metaiodobenzylguanidine Cardiac Scintigraphy, and [18F] FDG-PET

Advances in molecular imaging techniques and the increasing availability of functional imaging are expanding the role of nuclear medicine in neuroradiology. Molecular imaging has a well-established role in the evaluation of extrapyramidal disorders. In this setting, functional assessment can be combined with structural imaging to make a more accurate diagnosis. This is particularly useful in a number of more clinically challenging pathologies. This review discusses the role and context of imaging in extrapyramidal disorders. Structural imaging with MR imaging in combination with iodine 123 N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane SPECT (dopamine transporter SPECT), iodine 123 metaiodobenzylguanidine cardiac scintigraphy, and [18F]FDG-PET can be used to differentiate various underlying disease processes including Parkinson disease, dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration.Learning Objective: To assess dopamine transporter studies qualitatively and semiquantitatively and categorize them as having normal, abnormal, or indeterminate findings and to understand the role of MR imaging, iodine 123 metaiodobenzylguanidine cardiac scintigraphy, and [18F] FDG-PET in advancing the differential diagnoses of patients with Parkinson disease and atypical parkinsonian syndrome

Brain Tumor Reporting and Data System: A Pictorial Review

Brain tumors are a diverse group of neoplasms that are a source of substantial morbidity and mortality worldwide. Primary gliomas constitute almost all malignant brain tumors, with the most aggressive as well as most common form in adults, grade IV glioma or glioblastoma multiforme, carrying an especially poor prognosis. Neuroimaging is critical not only in the identification of CNS tumor but also in treatment-planning and assessing the response to therapy. Structured reporting continues to gain traction in radiology by reducing report ambiguity and improving consistency, while keeping referring clinicians and patients informed. The Brain Tumor Reporting and Data System (BT-RADS) is a relatively new paradigm that attempts to simplify and maximize consistency in radiologic reporting. BT-RADS incorporates MR imaging features, clinical assessment, and timing of therapy to assign each study a score or category, which is, in turn, linked to a management suggestion. The purpose of this pictorial review article is to familiarize radiologists and nonradiology neurologic specialists alike with BT-RADS, highlighting both advantages and limitations, in the hope that adoption of this system might ultimately facilitate more effective communication and improve consistency among reports.Learning Objective: To describe the features and underscore the advantages and disadvantages of the Brain Tumor Reporting and Data System (BT-RADS), a relatively new classification system that attempts to simplify and maximize consistency in radiologic reporting

Encephalotrigeminal Angiomatosis: A Review with Emphasis on Head and Neck Manifestations

Encephalotrigeminal angiomatosis, also known as Sturge-Weber syndrome or Sturge-Weber-Dimitri disease, is a sporadic congenital neurocutaneous syndrome characterized by angiomas of the face, eyes, and meninges. The typical clinical findings include seizures, a port-wine facial nevus, hemiparesis, and developmental delay. The classic intracranial imaging features of Sturge-Weber syndrome include cerebral hemispheric atrophy, hypervascularity and/or calcification of the cortex, and ipsilateral choroid plexus enlargement. Extracranial findings primarily include the vascular abnormalities of the ocular and facial soft tissues as well as hypertrophy of the calvarial and maxillofacial osseous structures. Additionally, we report involvement of the extraocular muscles, salivary glands, and lacrimal glands, findings that have not been well described in the literature. While a developmental venous pathology underlying Sturge-Weber syndrome has been proposed resulting in many of the findings, the mechanism behind the facial soft-tissue abnormalities and the clinical sequelae associated with these glandular abnormalities is still uncertain.Learning Objective: To recognize typical clinical and various imaging manifestations of Sturge-Weber syndrome, including head and neck and intracranial imaging findings

What We Should Not Forget about Down Syndrome

Down syndrome is the foremost common genetic cause of intellectual disability. The additional copy of chromosome 21 confers potential changes in virtually all organ systems, including the brain, neck structures, and spine. Neuroradiologists should be aware of the multitude of imaging findings in patients with Down syndrome to correctly identify and diagnose life-altering conditions associated with this syndrome. In particular, the high prevalence of age-related cognitive decline and dementia stands out more clearly in recent decades due to the notable increase in these individuals' survival. Although the early and timely diagnosis of cognitive decline in patients with varying degrees of intellectual disability has not been an easy task from the clinical point of view, anatomic and functional brain studies have shown an essential role because they allow the early recognition of abnormalities that precede the cognitive decline. Furthermore, the similarities and differences in neuropathologic, genetic, and imaging aspects in patients with Down syndrome have allowed extrapolation for a better understanding of the mechanisms linked to Alzheimer disease development.Learning Objective: To review and systematize the distinctive characteristics and abnormalities of the head and neck, vertebral column, and CNS present in Down syndrome

Revisiting the Embryology of the Facial Muscles, the Superficial Musculoaponeurotic System, and the Facial Nerve

The facial muscles are responsible for nonverbal expression, and the manner by which these muscles function to express various emotions are reviewed. How one recognizes these various facial expressions and how individuals can alter their facial expression are discussed. The methodology for cataloging facial expressions is also presented. The embryology of the facial muscles; the facial ligaments; and the supporting superficial musculoaponeurotic system, which magnifies the muscle movements, is also reviewed as is the embryology of the facial nerve, which innervates these muscles. Also, a detailed MR imaging atlas of the facial muscles is presented.Learning Objective: The reader will learn how the facial muscles develop and how they are the means of human nonverbal emotional expression. The anatomy of the facial ligaments and the superficial musculoaponeurotic system are also discussed

Opercular Perivascular Cyst: Old Entity, New Location

Dilated perivascular spaces in the brain have typical neuroimaging appearances. The classification of dilated perivascular spaces is based on their relationship to blood vessels and is divided into 3 subtypes. A fourth type has been described and termed “opercular perivascular space.” We report on an incidental finding of an opercular perivascular space on MR imaging. Dilated perivascular spaces are benign; it is important to be familiar with their characteristic appearance to prevent reporting them as a neoplasm.