Computed tomographic evaluation of ocular trauma

The CT scans of 10 traumatized patients with demonstrable ocular injuries were reviewed. The CT findings were correlated with the clinical findings in each case. CT manifestations of a variety of ocular and orbital injuries are reported and a systematic approach to the CT evaluation of ocular trauma is presented.

Chiasmal syndrome in sarcoidosis

Four patients had involvement of the anterior visual pathway by sarcoidosis. In two cases recognition of the systemic disease was delayed because only visual symptoms were present. Three cases had evidence of hypothalamic-pituitary axis dysfunction, with histologically proved granulomatous infiltration of this region. The chiasmal syndrome in sarcoidosis is characterized by a pattern of blindness in one eye, atrophy of the optic discs, and temporal visual field loss in the contralateral eye with variable degrees of pituitary dysfunction. The condition is medically treatable and simulates the clinical and even the roentgenographic appearance of a pituitary tumor.

Ischemic chiasma syndrome

Thirty patients with chiasma syndrome attributed to ischemic processes of various origins are described. The initial diagnosis was made after an investigation based on polytome pneumoencephalography and angiography. This diagnosis was confirmed later with the use of high-resolution computed tomography (CT) and refined angiographic techniques. The ischemic chiasma syndrome may be classified into five pathogenetic categories: (1) mechanical compression of the chiasm secondary to ectatic tortuous arteries; (2) vascular occlusion secondary to atheromatous plaque formation; (3) arachnoiditis with fibrosis; (4) arteritis of various origins; and (5) postpartum necrosis. Sophisticated neurologic procedures including magnification angiography and high-resolution CT are essential in ruling out a mass lesion and correlating the clinical and radiologic findings of this syndrome.

Meningioma of the paranasal sinuses

Meningiomas originating in the paranasal sinuses are rare. These tumors are thought to arise from embryonal arachnoid nests which were pinched off and left behind during embryonic development. We have described various radiographic findings of two patients with meningioma arising in the paranasal sinuses (frontal sinus origin in a 65-year-old female, and sphenoid sinus origin in a 26-year-old female). The paranasal origin of meningioma was accurately determined on the basis of CT and arteriography. A review of the 11 cases previously reported and our cases indicates that there are no specific clinical or radiographic findings of meningiomas of the paranasal sinuses.

Trans-sphenoidal removal of a Rathke's cleft cyst

Symptomatic Rathke's cleft cysts are uncommon. We present a case with suprasellar extension manifested by hypopituitarism and visual disturbances. The treatment was trans-sphenoidal evacuation and partial removal of the capsule. We suggest that the trans-sphenoidal approach to these lesions is usually adequate and that radical removal of the capsule is not necessary.

The value of radionuclide myelography in the evaluation of spinal arachnoiditis

On the basis of myelographic findings, spinal adhesive arachnoiditis was classified into three types: type I (peripheral or marginal), type II (central), and type III (advanced). Depending on its location and extent, it may be divided into group A (lumbar), group B (thoracic), and group C (cervical). In view of the fact that intrathecal injection both of oily and of water-soluble contrast media tends to produce spinal arachnoiditis, we have been using radionuclides for pre- and postoperative myelography to evaluate arachnoiditis. Radionuclide myelography with 131I-HSA or 111In-DTPA is a safe modality which provides useful information regarding spinal arachnoiditis.

Evaluation of cerebral infarction by computed tomography with special emphasis on microinfarction

Computed tomography has proved to be the most effective mode of evaluating cerebral infarction in 143 documented cases. This was especially true when multiple focal infarcts were present. The incidence of contrast enhancement in acute infarcts was 88%. Concomitant acute and old infarcts were observed in 20% of cases. In the acute stage of stroke, radionuclide studies are preferable to contrast angiography since the latter may aggravate the pre-existing focal ischemia. Follow-up CT and radionuclide scans were extremely useful in confirming the diagnosis and demonstrating various postinfarction sequelae.

Computed tomographic findings in cerebral hemiatrophy

The clinical, plain skull radiographic, brain scan, and CT findings of four patients with cerebral hemiatrophy are described. CT scanning is the most innocuous and most sensitive diagnostic method available to confirm the clinical diagnosis when plain skull radiographic changes are not confirmatory.

The value of computerized tomography in delineating suprasellar extension of pituitary adenoma for radiotherapeutic management

Radiotherapy plays a major role in the management of pituitary adenomas, either as a surgical adjunct or as the primary form of treatment. Small field precision techniques are utilized. The ability to employ limited field therapy and produce local control rates of 80--90% demands precise tumor localization. The extrasellar extension of pituitary adenomas has classically been demonstrated on angiographic and pneumoencephalographic examinations. Direct superior extension is accurately delineated by these examinations; lateral extension, however, is not and the total anterior-posterior extent of the tumor may be underestimated. The addition of computerized tomography significantly increases the information available in the assessment of tumor extension and the subsequent accuracy of treatment planning for radiotherapeutic purposes.

The role of ultrasonography in the diagnosis of certain neurologic disorders. A preliminary report

Ultrasonography is the most innocuous and noninvasive procedure, ideally suited for screening patients suspected of having cerebrovascular insufficiency. The Doppler ultrasound and real-time techniques complement each other. The latter can actually display a two-dimensional dynamic image of the carotid artery. B-scan can also be used in fetuses, infants, and young children for precise assessment of the size of the ventricular system. It can be used for serial follow-up evaluation of hydrocephalus. Ultrasound can be utilized in determination of the depth and width of the lumbar spinal canal. Differentiation of cystic from solid masses in the spinal canal may also be made by this modality.

The vasculature of the diaphragma sellae. A postmortem injection study

The postmortem injection study demonstrated that the main blood supply to each quadrant of the competent diaphragma sellae appears to come from the following vessels: posterior quadrant, inferior hypophyseal arteries; right and left marginal quadrant, tributaries of the intracavernous portion of the carotid artery; anterior marginal quadrant, anterior capsular arteries. When the diaphragm is incomplete or absent the inferior hypophyseal arteries are the main source of blood supply. Microscopic analysis of the vascular bed in the diaphragma sellae reveals that there are fine arterial filaments mostly in the superior layer, while venules are situated in the inferior part of the diaphragm.

The value of computed tomography in delineating suprasellar extension of pituitary adenomas

Pituitary tumors commonly produce suprasellar extension. We have found that in assessing lateral suprasellar extent, the pneumoencephalogram and arteriogram are least accurate. CT scanning significantly increases the accuracy, and it is recommended that all patients with pituitary tumors have an initial CT scan.

The value of computed tomography in the radiotherapeutic management of juxtasellar tumors

Computerized tomography has proven to be extremely useful for accurate tumor localization and precise assessment of tumor extent in the juxtasellar region. A reconstruction and display system with ACTA scanner provides three-dimensional images from the serial two-dimensional sections. With this method, one can determine the volume and actual contour of the tumor. Using the ACTA scanner, both transaxial and coronal sections of the tumor can be precisely portrayed with accurate dimensions. With the aid of CT treatment planning, we have been successfully treating such radiocurable tumors as pituitary adenomas, germinomas, craniopharyngiomas and optic gliomas.

CT evidence of grey matter calcification secondary to radiation therapy

There are four previously reported cases of post-irradiation calcification in the basal ganglia as demonstrated on the conventional skull roentgenograms. We have described two additional cases with grey matter calcification, which were demonstrated 10 and 14 yr after radiation therapy for an optic glioma and a medulloblastoma, respectively. The calcification was clearly demonstrated on CT scan, although it was not apparent on the skull roentgenogram. The extract pathogenesis of this condition is not clear. It appears, however, to be related to radiation vasculitis of the small vessels of the brain with resultant hyalinization and calcification. A long-term follow up study would be necessary to evaluate the significance and implication of post-irradiation calcification of the grey matter. CT is the most sensitive method of demonstrating the intracranial calcification in vivo.

Juxtasellar hyperostosis of non-meningiomatous origin

Seven patients are described who had juxtasellar hyperostosis with visual disturbance secondary to non-meningiomatous lesions. Two had chromophobe adenomas, one craniopharyngioma, one carcinoma of the sphenoid sinus, one a thrombosed aneurysm of the intracavernous portion of the internal carotid artery, one epidermoidoma of the orbit, and one chondroblastoma of the anterior clinoid process. The diagnosis of meningioma was entertained initially on the basis of hyperostosis plus visual impairment. Careful evaluation of hyperostosis is essential for correct diagnosis of meningioma, according to our experience. Suprasellar meningiomas almost invariably produce irregular hyperostosis of the planum sphenoidale, often associated with serration and blistering. Sphenoid meningioma, when it is sclerotic, always shows thickening or expansion of the sphenoid wings. Therefore, in the absence of typical meningiomatous hyperostosis, one can readily differentiate non-meningiomatous hyperostosis from true meningioma.

The diagnostic value of hyperostosis in midline subfrontal meningioma

Roentgenologic analysis of 66 patients with proved midline subfrontal meningioma indicates a very high incidence of hyperostosis. A total of 63 patients (95%) showed varying degrees of hyperostosis involving the cribiform plate, planum sphenoidale, or tuberculum sellae (including the chiasmatic sulcus). The planum sphenoidale is the most common site of hyperostosis (59%). In 19 cases (29%), the region of hyperostosis did not correspond to the site of tumor attachment. Mild or localized hyperostosis may be apparent only on tomograms. Small "blistering" and "saw-tooth-like" osteoma formation are reliable early signs of midline subfrontal meningioma; conversely, midline subfrontal meningioma can be virtually ruled out if hyperostosis is absent.

Angiographic findings in recurrent meningioma

Of 147 patients who underwent radical surgery for intracranial meningioma, 25 (17%) had symptomatic recurrence requiring further surgery. Correlation between histological and angiographic findings of recurrent meningioma was poor. Following extirpation of feeding meningeal vessels in convexity meningiomas, the principal blood supply was usually from the anterior, middle, and/or posterior cerebral arteries. The angiographic appearance was that of a "tree-root" or "sunburst" pattern, indicating neoplastic invasion of the pia mater and/or underlying brain tissue. Polytomography, selective cerebral angiography, and radionuclide imaging of the brain are often necessary to detect early recurrent meningiomas. Computed tomography appears to be an innocuous and accurate method of diagnosing recurrent tumor, especially when the bone is not involved.

Ischemic chiasmal syndrome

Twenty-two patients with ischemic chiasmal syndrome (ICS) have been examined by means of magnification angiography and polytomographic encephalography. The causes of ICS may be divided into 5 categories: (1) mechanical compression of the chiasm by ectatic redundant anterior cerebral arteries, (2) atherosclerotic vascular occlusions, (3) optochiasmal arachnoidal fibrosis, (4) various forms of arteritis especially giant cell (cranial) arteritis, and (5) post-partum pituitary necrosis associated with ICS. The most common cause of ICS appears to be optochiasmal arachnoiditis which occasionally developed some time after a craniotomy and radiation therapy for pituitary or other juxta-sellar tumors; similar fibrotic change may develop following steroid treatment of granulomatous lesions.