Extracranial optic nerve decompression for traumatic optic neuropathy.

We examined 14 patients with acute, unilateral optic nerve injury after blunt head trauma. In each patient the optic canal was decompressed through an ipsilateral external ethmoidectomy. The patients also received treatment with dexamethasone during the perioperative period. There was no morbidity or mortality. Eleven of the 14 patients improved, including 3 of the 5 who could not perceive light preoperatively. Transethmoid-sphenoid optic canal decompression is a safe and effective treatment for indirect optic nerve trauma.

The role of MR and CT in evaluating clival chordomas and chondrosarcomas.

Sixteen chordomas and nine chondrosarcomas of the clivus were evaluated with CT and MR either before (22 cases) or after (three cases) treatment with proton beam irradiation. The ability of these imaging techniques to provide information necessary to direct patient treatment was studied. The tumor was detected and its gross margins were identified by both techniques in all instances. No reliable diagnostic features allowing differentiation between these two tumors were encountered. MR generally was superior in defining the exact position of the brainstem and optic chiasm relative to the tumor, and it frequently provided superior information about tumor extension into the nasopharynx and cavernous sinus. CT was always better than MR in demonstrating tumoral calcification and in defining the exact anatomy of bone destruction. MR was generally superior to CT in demonstrating the position of the cavernous internal carotid artery relative to the tumor and often provided superior visualization of the vertebral and basilar arteries. In cases in which bone-induced artifact obscured the interface between the neural axis and tumor in the CT image, or in which the tumor had suprasellar extension and was likely to compress the optic chiasm and tracts, MR was of great value in planning irradiation therapy. The high occurrence of clinically asymptomatic signal intensity alterations in the MR studies of previously treated patients appears to limit the differential diagnostic value of this information. Given its greater availability and lower cost, CT appears to be the technique of choice for routine follow-up of previously treated patients.

Chordomas: their CT appearance in the cervical, thoracic and lumbar spine.

We reviewed 25 CT scans of 21 patients who had chordomas in the cervical, thoracic, or lumbar spine. Nine patients were studied at the time of initial presentation and 12 after tumor recurrence. All scans showed vertebral body destruction coupled with an associated soft tissue mass located anteriorly or laterally. Additional CT findings included septated areas of low attenuation within the tumor, amorphous soft tissue calcification, tumor extension into the spinal canal, disk space involvement, and contrast enhancement.

Hearing loss in skull fractures.

One hundred three cases of skull fractures in or around the temporal bone were reviewed for hearing loss. Of these, 100 patients had skull series, 66 had computed tomographic head scans, and 44 had polytomographic studies of the temporal bone. Hearing loss in head trauma can be grouped into four categories: conductive hearing loss, peripheral sensorineural hearing loss, central sensorineural hearing loss, and combinations of these hearing losses. The cause of conductive hearing loss and peripheral sensorineural hearing loss was usually identified by the type of temporal bone fracture. However, the cause of the central sensorineural hearing loss was more difficult to correlate with the brain lesions shown in the computed tomographic scans.

Radiological aspects of inverted papilloma.

Of 115 proved cases of inverted papilloma, 81 were studied radiographically. The tumor was seen in both early and late stages. Many cases presented as recurrent tumor after multiple surgical procedures. A common radiologic presentation was a unilateral mass in the nasal fossa with opacification of the contiguous maxillary sinus in a moderately advanced tumor stage. However, other radiologic patterns were encountered and it was therefore impossible to categorize any of these findings as specific for inverted papilloma.

Orbital fracture evaluation by coronal computed tomography.

Coronal computed tomography produces orbital scans in a plane that is analogous to Caldwell-view x-ray films. Coronal computed tomography permits simultaneous visualization of the orbital walls and the orbital soft tissues, including all extraocular muscles. Using coronal computed tomography, we studied a series of patients with radiographically proven orbital floor fractures. We studied in detail three of these patients, one with a linear orbital floor fracture, one with a depressed orbital floor fracture, and one with a severely comminuted orbital floor. In two patients, coronal computed tomography showed inferior rectus muscle entrapment, which was confirmed at the time of surgery. In each patient, some bone fragments could be seen more discreetly on coronal computed tomography than on conventional polytomes. Coronal computed tomography may be used to help confirm extraocular muscle entrapment in patients with orbital floor fractures. Coronal computed tomography can also be used to examine patients with possible intraorbital foreign bodies, unexplained reduction of vision, or severely displaced bone fragments.

Evaluation of neonatal intracranial hemorrhage by computerized tomography.

Computerized tomographic (CT) brain scan was performed on 28 infants with unexplained cardiorespiratory and neurologic deterioration and bloody lumbar cerebrospinal spinal fluid. Fourteen of 20 with intraventricular hemorrhage (IVH) died; the six infants with lesser degrees of IVH survived. Significant subarachnoid hemorrhage (SAH) was demonstrable in three infants and three had negative scans despite bloody CSF. We have found that CT scans provide useful information about the size and extent of neonatal IVH and distinguished it from SAH. It also confirms the diagnosis of post-hemorrhagic hydrocephalus in these infants. Continued use of the CT scan will help us to understand the natural history and the effects of neonatal intracranial hemorrhage among the survivors of intensive care.

Computed tomography of the skull and facial structures: preliminary evaluation of direct coronal sections.

Skull and facial structures may be evaluated on computed tomography (CT), as well as the brain. A valuable new dimension to the study has been added with the feasibility of obtaining direct coronal sections using a wide gantry aperture. The patho-anatomical details of bone and soft tissues including the orbit and paranasal sinuses are well demonstrated. Direct viewing on a display console of an enlarged quadrant of the scan is of prime importance in diagnosing fine changes involving the thin facial bones.

Comparison of ultrasonography, computerized tomography (EMI scan), and radiographic techniques in evaluation of exophthalmos.

A series of 342 consecutive patients with unilateral exophthalmos of confirmed etiology have been studied with a combination of clinical investigative techniques. High resolution B-scan ultrasonography and computerized tomography proved to be the most valuable tests for detecting orbital tumors and inflammatory conditions. Ultrasonography demonstrated primary orbital tumors but failed to show intracranial and some secondary tumors. Computerized tomography demonstrated primary, secondary, and intracranial tumors but not cystic masses. Inflammatory conditions such as Graves' disease and pseudotumor were characterized by ultrasonography also, while computerized tomography was not reliable for this. Correct diagnosis of orbital abnormalities in this series was 82% with ultrasonography and 72% with computerized tomography. Combined accuracy of these two complementary tests was 97% for tumor diagnosis. Conventional radiography and polytomography revealed secondary bony changes but not primary orbital tumors and inflammation. Orbital venography and arteriography had a low yield with tumors but were essential for demonstrating arteriovenous abnormalities. Orbital diagnosis has been improved significantly with the two newer techniques of ultrasonography and computerized tomography.

Quantitative analysis of the pituitary fossa and gland in Cushing's disease.

With tomography and encephalography of 78 cases with primary Cushing's disease, changes in the appearance of the pituitary gland and fossa have been demonstrated in greater numbers than previously reported. One or more direct or indirect signs of enlargement of the pituitary gland either by hyperplasia, microadenoma, or adenoma occurred in 60 per cent. Most of these cases were unproved as to cell type because they were given proton beam therapy. There were more cases of pituitary enlargement in those with adrenalectomy in comparison to non-adrenalectomy cases and in those with pigmentation in comparison to non-pigmented cases. The high incidence of pituitary gland enlargement in the different phases of this disease supports the importance of this gland in the pathogenesis of primary Cushing's disease. Limitation in correlation of the pituitary fossa to size of the pituitary gland when the latter enlarges only slightly has been discussed.

The use of xeroradiography in the investigation of diseases occurring in the central nervous system.

A total of 88 cases of normal and pathological conditions of the skull, brain and spinal cord was studied by skull series, pneumoencephalography, and air myelography. The roentgenographic images of these structures were recorded by conventional roentgenograms, xeroradiograms, and tomogrrams and compared with each other. In general the high resolution and wide recording latitude of xeroradiography produced a more pleasing, sharper image than that obtained by conventional roentgenography. However, the individual tomographic image was superior to xeroradiography.

The Use of Computer Tomography in Ophthalmology.

Fifty-three orbital lesions of various types were studied by computer tomography to assess the capabilities and limitations of this technique. Although CT scanning in ophthalmology is in its infancy, results showed that it is useful in the investigation of a number of pathological conditions, including congenital anomalies, arteriovenous malformations, bone lesions, trauma, inflammation, granulomas, pseudotumors, epidermoid cysts, and tumors arising in or near the optic nerve, behind the optic bulb, or in the lacrimal region, as well as changes following eye surgery.