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Show Literature Abstracts Institute, 500 Sherbourne Street, Toronto, Ontario M4X lK9, Canada. Fourteen patients with orbital lesions were studied by magnetic reson,lnce using a Technicare unit with a 0.15-T resistive magnet. Thirteen of these patients underwent CT of the orbits with 5-mm slice thickness and orbital ultrasound (eight examinations with a Xenotec 303 ABX scanner and four examinations with a Cooper 404 Ultrascan, both using 10MHz transducers; one examination was done in a Diasonic scanner using a 7.5-MHz transducer). The orbital space-occupying lesions included two cavernous hemangiomas, one orbital varix, three thyroid ophthalmopathies, two pseudotumors, two sphenoid wing meningiomas, one optic nerve glioma, one solitary plasmacytoma, and one intrascleral epithelial cyst. The major advantage of magnetic resonance over CT is that there is no risk of ionizing radiation from the contrast medium. In addition, utilizing a T2 weighted spin echo with echo delay (TE) of 60 ms and repetition intervals (TR) of 1,000-ms pulse sequence, in some cases, it was possible to characterize fat-containing, fluid-containing, and solid tumors. In conclusion, magnetic resonance provided better anatomical details than can ultrasound but not as well as can CT, and ultrasound provided the best tissue characterization of the three modalities. Therefore, magnetic resonance using a 0.15-T resistive magnet does not show an advantage over the combination of CT and ultrasound in diagnosing orbital space-occupying lesions. Rosendo D. Dia:, M.D. • • • 4. Reference: Tucci, J. M., Maitland, C. G., Pcsolyar, D. W., Thomas, J. R., and Black, J. L.: Carotidcavernous fistula due to traumatic dissection of the extracranial internal carotid artery. A.f.N.R. 5: 828-829, 1984. Reprints: C. G. Maitland, M.D., Department of Neurology, National Naval Medical Center, 4301 Jones Bridge Road, Bethesda, MD 20814. A 4~-year-old man developed throbbing, rightSided neck pam 12 h after being punched in the right side of the neck. Subsequently, he noticed tingling and numbness in the left arm and face, occasional visual blurring, and a sensation of constriction of the visual fields bilaterally. A cerebral angiogram demonstrated a dissecting aneurysm extending from the upper cervical segment to the petrous segment of the right internal carotid artery. There was also concentric narrowing of the precavernous segment of the right internal carotid artery. Intracranially, there was evidence of a low-flow, carotid-cavernous fistula on the right. The patient's sensory symptoms resolved after 6 weeks. Two months later he noted a bruit in the right side of the head and infected right sclera. Physical examination showed a chemotic, congested, and protruded right eye. A repeat cerebral angiogram demonstrated enlargement of the right carotid-cavernous fistula. Most carotidcavernous fistulas occur after head trauma. This case demonstrates that traumatic carotid dissection, re- 200 mote from the cavernous sinus and without associated head trauma, can result in a carotid-cavernous fistula. Rosendo D. Diaz, M.D. • • • 5. Reference: Rothfus, W. E., and Latchaw, R. E.: Nonefficacy of routine removal of CSF during neurodiagnostic procedures. A.f.N.R. 5: 797-800, 1984. Reprints: W. E. Rothfus, M.D., Presbyterian-University Hospital, DeSoto at O'Hara Street, Pittsburgh, PA 15213. The charts of 750 consecutive patients who had had myelograms and cisternograms were reviewed to evaluate the value of routinely removing cerebrospinal fluid (CSF) for chemical and cytologic analysis. Emphasis was placed on the progress notes, laboratory summary sheets, and discharge notes to see how the information from the CSF studies was used by the clinicians. In 80% of the myelograms and 68% of the cisternograms, the CSF studies were completely normal. In most patients having CSF abnormalities, the information added little to the clinical differential diagnosis. A CSF abnormality never led to detection of an occult problem. In very few patients were the results of the CSF examinations documented in writing in the patient's charlo (Seven percent of these 750 patients were referred by the neuro-ophthalmology service and of these patients only 14% had CSF results commented on in writing in their charts.) The authors conclude that removal of CSF during neurodiagnostic procedures should not be automatic but should be tailored to the particular clinical situation. Rosendo D. Diaz, M.D. • • • 6. Reference: Yeates, A. E., Blumenkopf, B., Drayer, B. P., Wilkins, R. H., Osborne, D., and Heinz, E. R.: Spontaneous CSF rhinorrhea arising from the middle cranial fossa: CT demonstration. A./NR. 5: 820-821, 1984. Reprints: A. E. Yeates, M.D., Department of Radiology, Box 3808, Duke University Medical Center, Durham, NC 27710. A 45-year-old woman developed spontaneous ce. rebrospinal fluid (CSF) leakage from the left nostnl 3 weeks prior to admission. The patient del1led havmg trauma. CT metrizamide cisternography was performed and showed an air-metrizamide level in the left sphenoid sinus. The left sphenoid sinus was pneumatized laterally (pterygoid recess); therefore, the floor of the medial portion of the middle cranial fossa formed the roof of the laterally pneumatized sphenoid sinus. In addition, the medical aspects of the floors of both middle cranial fossae were irregular and pitted. High-density CSF (metrizamide) was seen passing through one of these pits ir the left mid~le cranial fossa. A left subtemporal craniotomy confirmed the CT findings. Pitting in the floor of the Journal of Clinical Neuro-ophthalmology |