Search

BACKGROUND AND PURPOSE: The use of gadolinium-based contrast agents contributes to the cost of MR imaging and prolongs image-acquisition time. There are also recent concerns regarding gadolinium deposition, particularly in patients who require frequent follow-up MRIs. The purpose of this study was to assess whether gadolinium-based contrast agents are needed during MR imaging follow-up for unoperated pituitary macroadenoma. MATERIALS AND METHODS: A total of 105 patients with unoperated pituitary macroadenoma who underwent follow-up MR imaging of the sella were included in this retrospective study. The craniocaudal dimension, cavernous sinus invasion grading, and optic pathway compression were assessed independently on coronal T2WI and compared with coronal T1-weighted images with gadolinium-based contrast agents (T1 postcontrast images). The agreement between the T2WI and T1 postcontrast images for the craniocaudal dimension was assessed using the intraclass correlation coefficient; for the cavernous sinus invasion and optic pathway compression, it was assessed using κ statistics. RESULTS: There was excellent agreement for the craniocaudal dimensions between T2WI and T1 postcontrast images (intraclass correlation coefficient = 0.96, P

Aim: Periventricular leukomalacia (PVL) is a term reserved to describe white matter injury in the premature brain. In this review article, the authors highlight the common and rare pathologies mimicking the chronic stage of PVL and propose practical clinico-radiological criteria that would aid in diagnosis and management. Methods and Results: The authors first describe the typical brain MRI (magnetic resonance imaging) features of PVL. Based on their clinical presentation, pathologic entities and their neuroimaging findings were clustered into distinct categories. Three clinical subgroups were identified: healthy children, children with stable/nonprogressive neurological disorder, and those with progressive neurological disorder. The neuroradiological discriminators are described in each subgroup with relevant differential diagnoses. The mimics were broadly classified into normal variants, acquired, and inherited disorders. Conclusions: The term “PVL” should be used appropriately as it reflects its pathomechanism. The phrase “white matter injury of prematurity” or “brain injury of prematurity” is more specific. Discrepancies in imaging and clinical presentation must be tread with caution and warrant further investigations to exclude other possibilities.

Perinatal stroke ranks second only to that of adult stroke in the overall stroke incidence. It is a major contributor to long-term neurological morbidity, which includes cognitive dysfunction, cerebral palsy and seizures. Risk factors for stroke in the perinatal period differ from those in children and tend to be multifactorial. Differences in territorial predilection, response to injury, and stroke evolution exist when compared with childhood and adult stroke, and also among differing gestation age groups in the perinatal period (i.e., extreme preterm versus preterm versus term). The role of imaging is to diagnose stroke, exclude stroke mimics, establish the nature of stroke (arterial versus venous), and aid in prognostication. Magnetic resonance imaging is the mainstay of neuroimaging in perinatal stroke. Advanced imaging techniques such as diffusion tensor imaging and perfusion-weighted imaging are emerging as useful supplements to conventional imaging sequences. Here we describe the neuroimaging of perinatal arterial ischemic stroke with emphasis on imaging techniques, imaging phenotypes, stroke evolution, role of advanced imaging, and differences between stroke in preterm and term neonates. We also briefly describe the emerging role of fetal magnetic resonance imaging in the diagnosis of in utero stroke.

Brain tumors are the most common solid tumors in the pediatric population. Pediatric neuro-oncology has changed tremendously during the past decade owing to ongoing genomic advances. The diagnosis, prognosis, and treatment of pediatric brain tumors are now highly reliant on the genetic profile and histopathologic features of the tumor rather than the histopathologic features alone, which previously were the reference standard. The clinical information expected to be gleaned from radiologic interpretations also has evolved. Imaging is now expected to not only lead to a relevant short differential diagnosis but in certain instances also aid in predicting the specific tumor and subtype and possibly the prognosis. These processes fall under the umbrella of radiogenomics. Therefore, to continue to actively participate in patient care and/or radiogenomic research, it is important that radiologists have a basic understanding of the molecular mechanisms of common pediatric central nervous system tumors. The genetic features of pediatric low-grade gliomas, high-grade gliomas, medulloblastomas, and ependymomas are reviewed; differences between pediatric and adult gliomas are highlighted; and the critical oncogenic pathways of each tumor group are described. The role of the mitogen-activated protein kinase pathway in pediatric low-grade gliomas and of histone mutations as epigenetic regulators in pediatric high-grade gliomas is emphasized. In addition, the oncogenic drivers responsible for medulloblastoma, the classification of ependymomas, and the associated imaging correlations and clinical implications are discussed. ©RSNA, 2018.

Lysosomal storage disorders are a heterogeneous group of genetic diseases characterized by defective function in one of the lysosomal enzymes. In this review paper, we describe neuroradiological findings and clinical characteristics of neuronopathic lysosomal disorders with a focus on differential diagnosis. New insights regarding pathogenesis and therapeutic perspectives are also briefly discussed.

Primary cutaneous adenoid cystic carcinoma (ACC) is a rare skin tumor that is unlikely to metastasize. We present a case of primary cutaneous ACC in a 67-year-old male with axillary lymph node, pulmonary and brain metastases. To the best of our knowledge, this is the first reported case of cutaneous ACC with distant metastases to the brain.

Dementia is defined as chronic deterioration of intellectual function and cognitive skills significant enough to interfere with the ability to perform daily activities. Recent advances in the treatment of dementia have renewed interest in the use of various neuroimaging techniques that can assist in the diagnosis and differentiation of various subtypes. Neuroimaging and computational techniques have helped the radiological community to monitor disease progression of various neurodegenerative conditions presenting with dementia, such as Alzheimer disease, frontotemporal lobe dementia (FTLD), progressive supranuclear palsy (PSP) and multisystem atrophy-cerebellar variant (MSA-C), and their response to newer therapies. Prompt identification of treatable or reversible forms of dementia, such as tumours, subdural haemorrhage and intracranial dAVF, is crucial for the effective management of these conditions. It is also prudent to recognize the imaging spectrum of metabolic, infective and autoimmune diseases with rapidly progressing dementia, such as methanol toxicity, central pontine myelinolysis (CPM), delayed post hypoxic leukoencephalopathy (DPHL), HIV, Creutzfeldt-Jakob Disease (CJD), Sjogren's syndrome, multiple sclerosis (MS), radiation necrosis and Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS), which are difficult to treat and often require palliative care. This pictorial review emphasizes various non-Alzheimer’s dementia entities and discusses their imaging highlights. Teaching Points • Non Alzheimer’s dementia constitutes a broad spectrum of conditions. • Neuroimaging plays an important role in differentiating treatable from irreversible dementia. • Neuroimaging is often non-specific in early stages of neurodegenerative conditions with dementia. • Neuroimaging plays an important role in the multimodal approach towards management of dementia.

Primary cutaneous adenoid cystic carcinoma (ACC) is a rare skin tumor that is unlikely to metastasize. We present a case of primary cutaneous ACC in a 67-year-old male with axillary lymph node, pulmonary and brain metastases. To the best of our knowledge, this is the first reported case of cutaneous ACC with distant metastases to the brain.