High signal on T1-weighted MR images of the head: a pictorial essay.

T1-weighted magnetic resonance images (T1WI) of the head may manifest high signal in many normal and pathologic situations. Normally, it may be seen in fatty tissues, certain artifacts, and in areas without a blood-brain barrier after gadolinium administration. It is also seen in the posterior pituitary gland and in certain instances in the anterior pituitary gland. Pathologically, it may occur in many lesions after gadolinium enhancement, in fatty and cystic lesions, and in lesions with paramagnetic content. Occasionally, it may be seen in calcium deposition. Many of these are described and illustrated.

Postradiation gliosarcoma with osteosarcomatous components.

A 49-year-old man developed a gliosarcoma with prominent osteoid components 15 months after surgical resection and postoperative radiation and chemotherapy for a right frontal glioblastoma multiforme. The recurrent tumor was distinguished from the original lesion by the presence of dense ossification, visible on CT, at the original tumor site. The relevant literature is reviewed.

Paraparesis, hypermanganesaemia, and polycythaemia: a novel presentation of cirrhosis.

Progressive myelopathy is a rare complication of chronic hepatic disease which has never been reported in the paediatric age group. We describe the 11 year course of an adolescent male with hepatic myelopathy caused by cryptogenic micronodular cirrhosis. His condition has been associated with persistent polycythaemia and extraordinary increases of whole blood manganese, with magnetic resonance imaging evidence of manganese deposition within the basal ganglia and other regions of the brain. The patient has developed neither liver failure nor parkinsonism. The pathophysiological bases of this multiorgan system disorder are described.

Binocular three-dimensional perception through stereoscopic generation from rotating images.

RATIONALE AND OBJECTIVES: The authors evaluated the clinical utility and potential applications of a binocular three-dimensional (3D) image display in diagnostic radiology. MATERIALS AND METHODS: Rotating video displays of computed tomographic (CT), magnetic resonance (MR) angiographic, and digital subtraction angiographic (DSA) image data were used to generate stereoscopic image displays with a 3D appearance. Eight physicians viewed and scored eight skeletal and eight vascular-interventional studies with a planar display mode and a cathode ray tube. Each physician then viewed the 3D display of the same data and assessed the change in image findings, as well as any corresponding changes in level of diagnostic confidence. RESULTS: Image findings changed in 78 (61%) of the 128 studies after viewing the 3D displays. In 94 (73%) of all 128 studies, the interpreters reported increased confidence in their perception of the findings. Results for the vascular-interventional and skeletal cases were generally very similar. CONCLUSION: Binocular 3D stereoscopic displays from rotating images were reported to provide better image conceptualization and a higher degree of confidence in the findings on the images.

Craniocervical junction venous anatomy on enhanced MR images: the suboccipital cavernous sinus.

BACKGROUND AND PURPOSE: The suboccipital cavernous sinus, a vertebral venous plexus surrounding the horizontal portion of the vertebral artery at the skull base, provides an alternative pathway of cranial venous drainage by virtue of its connections to the cranial dural sinuses, the vertebral venous plexus, and the jugular venous system. Knowledge of the anatomy of this system facilitates interpretation of images and might reduce the number of false-positive diagnoses of lesions, such as adenopathy or schwannoma. We hypothesized that this circulation could be visualized on contrast-enhanced, fat-suppressed T1-weighted MR images. METHODS: The craniocervical junctions of 14 patients were scanned using fat-suppressed, contrast-enhanced, T1-weighted MR sequences and evaluated for visibility of the following venous structures: suboccipital cavernous sinus, vertebral artery venous plexus, anterior and posterior condylar veins, vertebral venous plexus, internal jugular vein, and the marginal sinus. Both the right and left sides were assessed in at least two planes. The venous diameters were also measured. RESULTS: All the evaluated venous structures were seen routinely in all three planes, with the exception of the posterior condylar vein, known to be variably present, which was seen only one third of the time in the sagittal plane and two thirds of the time in the other planes. The posterior condylar vein also showed the greatest variability in size and symmetry. CONCLUSION: The suboccipital cavernous sinus and most of its associated venous circulation at the skull base are easily identified on contrast-enhanced, fat-suppressed T1-weighted MR images. The posterior condylar vein, known to be variably present, was not well seen in the sagittal plane and displayed the greatest variability in size and symmetry.

Pituitary gland. Variable signal intensities on MRI. A pictorial essay.

The anterior pituitary gland may exhibit high signal on T1-weighted (T1w) images and/or low signal on T2-weighted (T2w) images in several normal and pathological states. High T1w signal may be seen in normal fetuses, neonates, and in pregnant and postpartum women. It may also occur in Rathke's cleft cyst, craniopharyngioma, subacute hemorrhage, manganese deposition, melanoma, dermoid, and lipoma. Low T2w signal may be seen in hemorrhage, calcification, cystic lesion, hemochromatosis, melanoma, and vascular lesions. These are described and illustrated.

Giant cervical epidural veins after craniectomy for head trauma.

Markedly dilated cervical epidural veins and right upper extremity weakness developed in a 43-year-old man 4 months after contralateral craniectomy for head trauma. After cranioplasty, his symptoms improved markedly and the size of the veins returned to normal. These findings suggest that enlarged cervical epidural veins may occur without an underlying vascular lesion and that upper extremity weakness may occasionally be attributable to spinal cord venous stasis.

Self-induced ethmoidectomy from rhinotillexomania.

A 53-year-old woman with a long history of compulsive nose picking (rhinotillexomania) presented with a large, self-inflicted nasal septal perforation and right-sided penetration of the ethmoidal sinus, or "ethmoidectomy."

Smaller format, laser camera-generated images: acceptability and cost savings.

RATIONALE AND OBJECTIVES: To evaluate the use of laser-generated smaller images in neuroradiologic practice. MATERIALS AND METHODS: Computed tomographic (CT) scans of the heads of five subjects were obtained at bone and brain windows in three formats: 12:1 (12 images on a 35 x 43-cm film), 15:1 and 20:1. Two laser-camera systems were used. Images were measured, physically separated, and reconstructed as a 35 x 43-cm ensemble; they were presented randomly to seven radiologists who assessed image size and interpretability. Observer preference was also noted. One camera system was evaluated for contrast and spatial resolution by a medical physicist. RESULTS: These were negligible differences in image area between the 15:1 and 20:1 formats. No discernible differences in quality were found among the three formats. The 12:1 images were preferred by the radiologists, but the 20:1 images were deemed acceptable. Annualized cost savings of 46.7%, or $46,650, were projected for adoption of the 20:1 image format for neuroradiologic CT and magnetic resonance imaging. CONCLUSION: No major differences were detected in image area between the 15:1 and the 20:1 image formats or in image quality among the three formats. Use of a smaller image format may result in substantial cost savings.

Lymphoma of the esophagus.

A case of direct involvement of the esophagus by lymphoma is presented. The radiographic features were those of a diffuse intramural submucosal tumor, in contrast to the 6 previously reported cases.