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A persistent trigeminal artery (PTA) is the most common carotid-vertebrobasilar anastomosis. PTA variants terminating on cerebellar arteries instead of the basilar artery have been reported previously. We present the first case of a PTA communicating with a fetal posterior communicating artery identified on a magnetic resonance angiogram. An understanding of these anatomical variants is important to clarify pathological processes that can help guide neurosurgical and endovascular procedures.

A 30-year-old male presented with left facial pain and numbness. Initial MRI demonstrated an enhancing mass involving the left trigeminal nerve. Follow-up imaging showed interval growth with erosion of the sphenoid body. Surgical resection was performed and immunohistochemistry staining was consistent with an atypical teratoid/rhabdoid tumor. Awareness of this entity and its imaging features such as diffusion restriction, intratumoral hemorrhage, and bony destruction, can help guide confirmatory diagnostic testing and appropriate therapy., (© The Author(s) 2016.)

Jacobsen syndrome is a rare disorder caused by partial deletions of the long arm of chromosome 11. The phenotype is variable with involvement of multiple organ systems, resulting in congenital heart defects, blood dyscrasias, and impaired growth. We describe a case of a 30-year-old man with multiple ophthalmic manifestations and brain magnetic resonance imaging (MRI) that was remarkable for multiple T2-hyperintense subcortical white matter lesions. It is important to be aware that patients with Jacobsen syndrome may have nonspecific white changes seen on MRI., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To apply resting-state functional magnetic resonance (MR) imaging to map functional connectivity of the human spinal cord., Materials and Methods: Studies were performed in nine self-declared healthy volunteers with informed consent and institutional review board approval. Resting-state functional MR imaging was performed to map functional connectivity of the human cervical spinal cord from C1 to C4 at 1 × 1 × 3-mm resolution with a 3.0-T clinical MR imaging unit. Independent component analysis (ICA) was performed to derive resting-state functional MR imaging z-score maps rendered on two-dimensional and three-dimensional images. Seed-based analysis was performed for cross validation with ICA networks by using Pearson correlation., Results: Reproducibility analysis of resting-state functional MR imaging maps from four repeated trials in a single participant yielded a mean z score of 6 ± 1 (P < .0001). The centroid coordinates across the four trials deviated by 2 in-plane voxels ± 2 mm (standard deviation) and up to one adjacent image section ± 3 mm. ICA of group resting-state functional MR imaging data revealed prominent functional connectivity patterns within the spinal cord gray matter. There were statistically significant (z score > 3, P < .001) bilateral, unilateral, and intersegmental correlations in the ventral horns, dorsal horns, and central spinal cord gray matter. Three-dimensional surface rendering provided visualization of these components along the length of the spinal cord. Seed-based analysis showed that many ICA components exhibited strong and significant (P < .05) correlations, corroborating the ICA results. Resting-state functional MR imaging connectivity networks are qualitatively consistent with known neuroanatomic and functional structures in the spinal cord., Conclusion: Resting-state functional MR imaging of the human cervical spinal cord with a 3.0-T clinical MR imaging unit and standard MR imaging protocols and hardware reveals prominent functional connectivity patterns within the spinal cord gray matter, consistent with known functional and anatomic layouts of the spinal cord.

The facial nerve is affected by a wide variety of pathologies, including congenital, traumatic, inflammatory, and neoplastic conditions. Imaging plays a vital role in the diagnosis of these pathologies. The facial nerve has a complex anatomy and course. A strong grasp of normal facial nerve anatomy is essential for the radiologist to maintain a high level of diagnostic sensitivity. This article details the normal imaging anatomy of the facial nerve and the imaging features of common facial nerve pathologies., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Background and Purpose: Diabetes mellitus is an independent risk factor for lacunar strokes. Few data are available regarding patient features, infarct location, and recurrent vascular events for patients with diabetes mellitus with lacunar stroke., Methods: We compared features at study entry and prognosis during 3.6 years of follow-up of patients with diabetes mellitus versus patients without diabetes mellitus with recent lacunar stroke participating in the Secondary Prevention of Small Subcortical Strokes (SPS3) randomized trial., Results: Among the 3020 participants, the prevalence of diabetes mellitus was 37% with a mean duration of 11 years. Diabetes mellitus was independently associated with slightly younger age (63 versus 64 years; P<0.001), Hispanic ethnicity (36% versus 28%; P<0.0001), ischemic heart disease (11% versus 6%; P=0.002), and peripheral vascular disease (5% versus 2%; P<0.001). Patients with diabetes mellitus more frequently had intracranial stenosis ≥50% (P<0.001), infarcts involving the brain stem or cerebellum (P<0.001), and more extensive white matter abnormalities (P<0.001). Patients with diabetes mellitus were almost twice as likely to have a recurrent stroke (hazard ratio [HR], 1.8; 95% confidence interval [CI], 1.4-2.3), recurrent ischemic stroke (HR, 1.8; 95% CI, 1.4-2.4), disabling/fatal stroke (HR, 1.8; 95% CI, 1.2-2.9), myocardial infarction (HR, 1.7; 95% CI, 1.0-2.8), and death (HR, 2.1 95% CI, 1.6-2.8) compared with patients without diabetes mellitus., Conclusions: Patients with diabetes mellitus with lacunar stroke have a distinctive clinical profile that includes double the prevalence of systemic and intracranial atherosclerosis, preferential involvement of the posterior circulation, and a poor prognosis for recurrent stroke and death., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT00059306., (© 2014 American Heart Association, Inc.)

Fungal sinusitis was once considered a rare disorder but is now reported with increasing frequency throughout the world. The classification of fungal sinusitis has evolved in the past two decades, and this entity is now thought to comprise five subtypes. Acute invasive fungal sinusitis, chronic invasive fungal sinusitis, and chronic granulomatous invasive fungal sinusitis make up the invasive group, whereas noninvasive fungal sinusitis is composed of allergic fungal sinusitis and fungus ball (fungal mycetoma). These five subtypes are distinct entities with different clinical and radiologic features. The treatment strategies for the subtypes are also different, as are their prognoses. An understanding of the different types of fungal sinusitis and knowledge of their particular radiologic features allow the radiologist to play a crucial role in alerting the clinician to use appropriate diagnostic techniques for confirmation. Prompt diagnosis and initiation of appropriate therapy are essential to avoid a protracted or fatal outcome., ((c) RSNA, 2007.)

Bipolaris is an increasingly recognized cause of fungal sinusitis. Reports of imaging features are sparse. Our purpose was to review the imaging features in patients with Bipolaris fungal sinusitis. A review of our data showed seven patients with culture-proven Bipolaris fungal sinusitis. Computed tomography of the paranasal sinuses in all the patients and MRI in five patients were analysed for the location, nature, extent of the disease and density/signal characteristics on CT/MRI. The sphenoid and posterior ethmoid sinuses were most often involved (six of seven), followed by the anterior ethmoid sinus (five of seven), frontal sinus (four of seven) and maxillary sinus (three of seven) involvement. Five of seven cases had bilateral disease. Secretions were seen to fill the sinus and were expansile in nature in six of seven cases. Bony erosion was noted in all the patients. Air-fluid levels and bony sclerosis were rarely seen. Computed tomography showed central hyperdensity in all the cases. In the corresponding MR images (n = 5), the sinus contents appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Extension into the nasal cavity was found in six of seven cases. Five of seven cases had intracranial (extradural) spread. Intraorbital extension was seen in three of seven cases, with associated optic nerve compression in two. All the patients responded to surgical debridement, and systemic antifungal therapy was not required. Bipolaris fungal sinusitis typically presents with an allergic fungal sinusitis picture with expansile sinus opacification and bony erosions. There is central hyperdensity on CT scan, which appears hyperintense on T1-weighted and hypointense on T2-weighted MR images.

Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sign of disease advancement in three patients with clinically progressive posttraumatic syringomyelia. This craniad margin of parenchymal spinal cord T2 hyperintensity resolved after cystoperitoneal shunt placement. There was a concomittant reduction or disappearance of the cyst in each instance, a halt in the progression of neurologic deficit, and some reversal of signs and symptoms.

The MRI examinations of eight patients with cervical vertebral dislocation demonstrated by conventional radiography were reviewed. All patients had axial and sagittal T1- and T2-weighted imaging on a 1.5-T Unit. This revealed unilateral partial facet dislocation (in two patients), bilateral partial facet dislocation (in two), unilateral complete dislocation (in two) and bilateral complete facet dislocation (in two). In six patients there was cord contusion, three had focal disc protrusions and four unilateral absence of normal flow void in one of the cervical vertebral arteries. In all cases, the dislocated facets were shown well on the far-lateral sagittal images.

Purpose: The purpose of this study was to determine if infection-related disc protrusion formed a component of the perispinous/epidural mass in patients with intervertebral disc infection., Method: A retrospective review was undertaken of 16 consecutive patients with intervertebral disc space infection who were referred for gadolinium-enhanced MRI. Possible correlation was sought between disc infection and the presence of associated posterior disc protrusion as determined by MRI., Results: Of the 16 infected discs, 10 cases were in the lumbosacral spine, 3 in the thoracic spine, and 3 in the cervical spine. Four cases had isolated posteriorly directed disc protrusion, and 12 showed both posterior and anterior disc protrusions. The infection in patients with disc protrusion was related to Staphylococcus aureus in 14 patients, Salmonella enteritidis in 1, and Streptococcus pneumoniae in 1., Conclusion: This study showed that disc protrusion occurred in combination with disc space infections. Local factors such as the secretion by hyaluronidase from Staphylococcus aureus may play an important role in causing focal disc protrusion. The clinical importance of this finding is in the recognition that a significant part of the compromise of the spinal canal in cases of disc infection can be related to disc fragments engendered by the infectious process.

Purpose: To determine normal magnetic resonance (MR) imaging enhancement characteristics of the lumbosacral spine after intravenous administration of an expanded dose of gadopentetate dimeglumine., Materials and Methods: T1-weighted MR images of the lumbosacral spine were acquired before and after injection of 0.3 mmol/kg gadopentetate dimeglumine in 12 healthy subjects (eight men, four women; age range, 22-57 years)., Results: In 10 (91%) of the 11 subjects who completed the investigation, multifocal linear enhancement within the thecal sac that generally extended from the conus to the nerve-root sheaths was demonstrated. In all cases, enhancement was seen in the facet joints and the intervertebral disks parallel to the vertebral end-plates., Conclusion: After an expanded dose of intravenous gadopentetate dimeglumine, multiple intrathecal and extrathecal structures were enhanced. Recognition of normal enhancement patterns after an expanded gadopentetate dimeglumine dose is important because such enhancement after routine injection of 0.1 mmol/kg gadopentetate dimeglumine is often thought to indicate disease.

We describe the radiologic investigation of two patients with primary left atrial myxoma who presented with embolic manifestations in the brain. MRI and CT showed multiple infarcts, while the cardiac atrial mass was demonstrated in one of the patients by MRI and in both by echocardiography.

Study Design: The prevalence and appearance on MRI of lipomas of the filum terminale was studied in a random population referred to MRI for evaluation of the lumbosacral spine. The MRI scans of 100 patients selected at random were retrospectively reviewed., Objectives: The study sought to determine the frequency and MRI appearance of incidental filum lipomas in a random population., Summary of Background Data: Postmortem studies have reported a 4%-6% incidence of occult fibrolipomas of the filum terminale in what were thought to be otherwise normal spinal cords. The improved resolution of MRI imaging allows the detection of small amounts of fat associated with the filum terminale that heretofore had not been demonstrated on radiologic imaging examinations., Methods: The lumbosacral spine unenhanced MRI scans of 100 patients not previously operated upon were selected at random and were retrospectively reviewed by two of the authors (EB and JCM)., Results: Of the 100 MRI examinations reviewed, four patients were found to have small lipomas of the filum terminale. No spinal dysraphism or cord tethering were present in these four patients. Their clinical symptoms were related to disc herniation in two patients, spinal stenosis in one, and discitis in one. The lipomatous tissue was hyperintense to cerebrospinal fluid (CSF) on T1-weighted images and hypointense to CSF on T2-weighted images., Conclusions: Incidental lipomas of the filum terminale were present in 4% of 100 lumbosacral spine MRI examinations in a random population.

This report describes a subependymoma of the filum terminale evaluated by MRI. The mass demonstrated hyperintense signal on conventional spin echo T1-weighted, proton density, and T2-weighted imaging and nonenhancement after intravenous gadolinium administration. These characteristics distinguish this lesion from other more common neoplastic and inflammatory lesions arising in the lumbar spinal canal that are typically isointense on T1-weighted spin echo acquisitions, hyperintense on T2-weighted imaging, and enhance variably after intravenous gadolinium administration.

A 19-year-old woman with insulin-dependent diabetes mellitus developed pain and tenderness in the medial aspect of the left thigh and calf, followed 1 week later by similar symptoms in the right leg. Technetium 99m pyrophosphate (PYP) radionuclide scans showed increased flow and uptake in the medial thigh muscles. Magnetic resonance imaging (MRI) of the thigh showed increased signal on proton density and T2-weighted images in the medial and lateral thigh compartments. High-resolution B-mode ultrasound showed hyperechoic changes in the anteromedial thigh muscles, with loss of normal myofascial interfaces, and a mixed appearance, bilaterally. Two months later, after the symptoms had begun to resolve, the images had improved. This case documents bilateral diabetic thigh infarction identified by abnormal technetium 99m PYP flow studies, MRI signal, and B-mode ultrasound imaging.

Purpose: To evaluate the middle cerebral artery (MCA) on CT, including its relationship to cerebral infarction., Methods: Thirteen patients with either a unilateral or bilateral hyperdense M1 segment of the MCA were evaluated. History of hypertension, diabetes, and hematocrit were obtained and compared with a control group of patients without a hyperdense MCA., Results: None of the patients had a unilateral hyperdense MCA ipsilateral to a clinically identifiable stroke. Patients with a hyperdense MCA had a statistically higher hematocrit and also a higher prevalence of hypertension and diabetes mellitus than patients without a hyperdense MCA. The higher hematocrit may have increased the density of the blood, while both diabetes and hypertension are associated with calcification within blood vessel walls., Conclusion: A hyperdense MCA is not a reliable indicator of occlusion of this vessel or subsequent infarction.

We describe a young girl with neurofibromatosis and enlargement of the optic chiasm and intracranial left optic nerve. Serial MRIs over 32 months demonstrated spontaneous, marked reduction in the size of these lesions. Spontaneous regression must be considered in evaluating therapies for optic glioma.

Acquired immunodeficiency syndrome (AIDS) and AIDS-related infection of the brain constitute a large fraction of the most recent research into central nervous system infection. Two major areas of controversy discussed in the past year's literature were the neuroradiologic and neurologic manifestations of early human immunodeficiency virus infection in the central nervous system and differentiation of toxoplasmosis from lymphoma. Other non-AIDS related infections discussed included infectious aneurysms, bacterial abscesses, tuberculosis, cysticercosis, fungal infections, and zoster myelitis.

Radiation induced neoplasms of the spinal cord are rare lesions. This report details the MR evaluation of a patient with radiation induced astrocytoma of the cervical cord. The diagnosis of second primary neoplasm should be considered in patients with prior radiation therapy when MRI demonstrates an intramedullary lesion.

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.