L. Anne Hayman

The Evaluation of Isolated Third Nerve Palsy Revisited ☆: An Update on the Evolving Role of Magnetic Resonance, Computed Tomography, and Catheter Angiography

The evaluation and management of the neurologically isolated third nerve palsy continues to evolve. The major concern for the clinician confronted with a patient with a third nerve palsy has been the exclusion of an intracranial aneurysm. The evolution of new imaging techniques, such as computed tomography angiography and magnetic resonance angiography, have provided new imaging options for clinicians. This article reviews the pertinent recent literature on the use of these imaging studies in evaluating the patient with a third nerve palsy.

Coronal imaging of the osteomeatal unit: anatomy of 24 variants.

The purpose of this paper is to present a user-friendly reference for 24 of the most common normal variants of the osteomeatal unit. A five image set of consecutive normal coronal hanging head computed tomography (CT) images was obtained. Half of each image was duplicated enough times to allow superimposition of the variants. For organizational purposes, each variant was sorted into six color-coded regions: middle turbinate (five variants), inferior turbinate (three variants), maxillary sinus (three variants), nasal septum (three variants), ethmoid sinuses (five variants), and uncinate process (five variants). This reference can be used to rapidly identify a CT scan level and obtain an overview of common variants in that level. In addition, the color-coded system can be used to find any variant on all appropriate CT levels quickly by locating its colored column.

Accentuated Virchow-Robin spaces in the centrum semiovale in children with autistic disorder.

Objective: The purpose of this study was to assess the incidence of abnormal Virchow-Robin (VR) spaces in children and adolescents with an autistic disorder (AD). An increased incidence of enlarged VR spaces in children has been reported in several developmental disorders. Methods: Sixteen children and adolescents (13 male, 3 female; mean age = 143.5 months; mean IQ = 95.1) with an AD, verified by use of standardized procedures (Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule-Revised), received cranial magnetic resonance (MR) imaging. Sixteen children and adolescents (13 male, 3 female; mean age = 160.7 months; mean IQ = 111.6) without AD, as determined using the same procedures, were scanned as a comparison group. The MR scans were performed using a 1.5-T scanner. Two T1-weighted spoiled GRASS sequences (0.7-mm coronal thin-slice, 0-mm gap; 1.5-mm sagittal, 0-mm gap) and a complementary T2-weighted fast spin echo sequence (1.5-mm, 0-mm gap) were obtained. A neuroradiologist and a neurobiologist without clinical information determined the incidence of normal, accentuated, and/or dilated VR spaces. Results: Seven of 16 subjects with AD (approximately 44%) had dilated VR spaces in the centrum semiovale. No grossly abnormal spaces were present in the control subjects. Conclusion: Unusually large VR spaces are seen in at most 22% to 27% of MR scans in children with tension headaches and other psychiatric disorders, suggesting that the incidence of spaces of this type is greater in AD than in other abnormal populations. The origin and significance of this phenomenon remain unknown.

Rapid-high-dose contrast computed tomography of isodense subdural hematoma and cerebral swelling.

Ten patients were studied in whom precontrast computed tomography (CT) revealed an isodense mass which obliterated cerebral sulci and deformed the ventricle(s). Upon rapid-high-dose (RHD) contrast enhancement, the cerebral hemispheric surface was so well demonstrated, that in 4 patients the possibility of an isodense subdural hematoma was exluded, while in the other 6 it was correctly diagnosed. Preoperative angiography was not necessary.

Rapid high dose (RHD) contrast computed tomography of perisellar vessels.

The diagnostic accuracy of CT scanning in the sellar area can be improved by using a rapid high dose (RHD) contrast technique which visualizes the supraclinoid carotid arteries, cavernous sinus and vascular plexus of the infundibulum. The RHD technique is briefly described and the pertinent anatomy discussed and illustrated.

A computed tomographic guide to endoscopic sinus surgery: axial and coronal views.

SUMMARY The purpose of this article is to correlate endoscopic surgical procedures in the sinuses with computer tomographic (CT) scans. Twelve commonly performed procedures were color-coded on a set of normal coronal and axial CT scans. The illustrated procedures are uncinectomy/antrostomy, anterior ethmoidectomy, posterior ethmoidectomy, sphenoidotomy, partial inferior turbinectomy, partial middle turbinectomy, septoplasty, frontal recess approach, dacrocystorhinostomy, orbital decompression, optic nerve decompression, and medial maxillectomy. Drainage of a medial orbital abscess is discussed but not illustrated. A brief description of the indications, surgical approach, and complications of each procedure is also provided.

In Vivo Measurements of Temporal Bone on Reconstructed Clinical High-Resolution Computed Tomography Scans †

Purpose To retrospectively assess the accuracy of measurements of temporal bone anatomy made from reconstructed clinical high‐resolution computed tomography (HRCT) scans.

Adult cranial dura I: intrinsic vessels.

This is the first of two articles designed to provide user-friendly schematics of the adult dural vascular anatomy. It describes the intrinsic meningeal arteries and veins of the skull base/cranial vault and the dural partitions (the tentorium, falx cerebelli, and falx cerebri). The discussion of this anatomy is supplemented by illustrative pathologic insights. The second article focuses on the dural sinuses and their remaining tributaries from the brain, diploë, and emissary veins from the extracranial soft tissues. This information will assist in interpreting neuroimaging studies, communications with clinicians, and teaching of this difficult subject.

Reconciliation of the anatomic, surgical, and radiographic classifications of the mediastinum

The mediastinum is a complex region that is variously subdivided by radiologists, surgeons and anatomists. This paper describes the most popular of these classifications and color-codes the radiologic and surgical divisions on 22 labeled axial sections of the chest. This allows the reader to quickly name the appropriate location of a lesion on any section.

Neuroimaging contrast agents in ophthalmology.

Magnetic resonance (MR) imaging and computed tomography (CT) are routinely performed with the use of contrast materials in the diagnosis of neuro-ophthalmologic disease. Iodinated agents are commonly used in CT scanning and femoral contrast arteriography, and gadolinium is used in MR imaging. While contrast materials contribute greatly to diagnostic accuracy, they may also be responsible for adverse effects, ranging in severity from mild discomfort to death. The most frequent and severe side effects are associated with ionic iodinated contrast agents, while the rate of adverse reactions is less with use of nonionic iodinated contrast agents. Side effects and adverse reactions to gadolinium are uncommon, but they do occur. In neuro-ophthalmologic diagnosis, MR imaging is generally preferred over CT scanning, partly because of its greater ability to delineate soft tissue intracranial structures, but also because of the relative safety of gadolinium as a contrast agent. Properties of contrast agents are discussed in the context of specific imaging techniques and tissues investigated. Types and severity of adverse effects as well as risk factors for incurring such effects are summarized.