Richard A. Kramer

Computed Tomography of Angiographically Occult Cerebral Vascular Malformations

Although some cerebral vascular malformations are angiographically occult, the correct diagnosis may be suggested by their appearance on computed tomography (CT). The authors advise caution in assuming that angiographically avascular lesions which show contrast enhancement on CT represent neoplasms rather than vascular malformations.Although some cerebral vascular malformations are angiographically occult, the correct diagnosis may be suggested by their appearance on computed tomography (CT). The authors advise caution in assuming that angiographically avascular lesions which show contrast enhancement on CT represent neoplasms rather than vascular malformations.

An Approach to Contrast Enhancement in Computed Tomography of the Brain

A total of 450 brain examinations were performed using computed tomography before and after intravenous infusion of methylglucamine diatrizoate 30%. In 110 cases involving a documented intracranial lesion, the scans were analyzed to determine the degree and usefulness of contrast enhancement. Enhancement was achieved in a wide variety of neoplastic and non-neoplastic lesions and was found to be of considerable help in detection of abnormality as well as in defining tumor morphology.

Computed Tomography in Primary Reticulum Cell Sarcoma of the Brain

The CT findings in 16 patients with histologically proved primary central nervous system (CNS) reticulum cell sarcoma (RCS) showed this malignancy to have predilection for the basal ganglia and thalamus, the periventricular white matter, the corpus callosum, and the vermis cerebelli. In 43% of patients with untreated tumor it presented as multifocal lesions; in each of these patients the basal ganglia were involved in conjuction with another site. In the other 57% of patients with untreated tumor presenting as solitary lesions the basal ganglia, the corpus callosum, and the frontal lobe were sites of predilection. Such solitary lesions may be indistinguishable from other tumors. Contrast enhancement of RCS was characteristically homogeneous with rare lucency, even in very large lesions.

Malignant Melanoma Metastatic to the Central Nervous System

The CT appearance of metastatic malignant melanoma is varied, but it can show features suggesting the correct diagnosis. Intracerebral hemorrhage alone, associated with an adjacent tumor nodule or mixed diffusely with a tumor, occurred in 10 of 33 patients. Identification of a tumor nodule is important, since it may be the site of recurrent hemorrhage if not removed completely at surgery. Unusual presentations such as meningeal carcinomatosis and lesions simulating primary gliomas also occurred.

Catheter Technic in Vertebral Arteriography

Selective catheterization of the vertebral artery represents an easy and safe approach to vertebral arteriography. Although this technic has been previously described (2–4, 6, 8), it has not been widely used. For the past two years selective vertebral artery catheterization has been employed at the University of California Hospitals, San Francisco, and in the following report our experience with this technic is reviewed. Technic The vertebral artery may be catheterized from either the axillary or the femoral artery. In elderly patients, transfemoral vertebral catheterization may be difficult because of tortuosity and elongation of the aorta and of the brachiocephalic vessels. Inthese instances thetransaxillaryapproach has proved useful (5, 12). In patients younger than fifty-five years, the vertebral artery is usually easily catheterized by way of the femoral artery. Usually, a local anesthetic is employed for the examination, a general anesthetic being administered only to young children or unco-operativ...

Statistical profiles in computed tomography.

A diagnostic console consisting of a high resolution video display coupled to a microcomputer was programmed to enable us to derive a battery of statistical parameters from any area of interest on a CT scan. These statistical parameters enable us to characterize the CT numbers of areas of interest in a more meaningful way than has been possible with most currently available consoles. A combination of statistical parameters enables us to discriminate between certain lesions with similar appearance such as porencephalic cysts, epidermoid tumors and cystic gliomas.