Hillier L. Baker

Intracranial dural arteriovenous malformations.

Abstract Twenty-eight patients with dural arteriovenous malformations, mostly located along the cranial base and in the occipitomastoid region, were studied angiographically. It was often possible to define a relationship between the clinical syndrome and the angiographic pattern of venous drainage. Intracranial hemorrhages occurred in those patients in whom the venous drainage of the arteriovenous malformation was limited to the pial veins, while the syndrome of a cavernous sinus fistula was present when retrograde venous drainage from the anomaly extended through the distensible ophthalmic veins. If the venous outflow was antegrade through the usual channels, the clinical syndrome reflected only the presence and volume of the arteriovenous shunt.

The Lateral Roentgenogram of the Neck

The lateral cervical roentgenogram is a useful guide in evaluating the bony and soft-tissue relationships of the neck. In an effort to establish certain normal measurements in this area we reviewed 700 lateral cervical roentgenograms from the files of the Mayo Clinic, of which 600, technically adequate and without detectable abnormalities, were included in the study. The roentgenograms were taken with the patient sitting erect and with the neck in the neutral position. The target-to-film distance was 60 inches. Measurements were made from the films without correction for the minor error due to magnification. Regions Evaluated Retropharyngeal Space: In Figure 1 the retropharyngeal space is indicated by the letter A. For convenience, we chose to measure this from the antero-inferior aspect of the second cervical vertebra to the posterior wall of the pharynx. Retrotracheal Space: The retrotracheal space, represented in Figure 1 by the letter B, was measured from the anteroinferior aspect of the sixth cervica...

Duration of cigarette smoking is the strongest predictor of severe extracranial carotid artery atherosclerosis.

The effect of cigarette smoking on extracranial carotid atherosclerosis was studies by obtaining cigarette smoking histories and information on other potential risk factors from consecutive patients undergoing carotid arteriography. At least on extracranial carotid artery was visualized in 752 patients in whom the extent of carotid atherosclerosis was assessed. The total years of cigarette smoking was the most significant independent predictor of the presence of severe carotid atherosclerosis. Other independent predictors, in order of significance, were age, hypertension, diabetes mellitus, male sex, and current systolic blood pressure. By age 60 years, the risk of having severe carotid atherosclerosis for a person who had smoked for 40 years was approximately 3.5 times that for a never smoker. The major benefit of smoking cessation is in limiting the accumulation of smoking years.

MR findings in normal-pressure hydrocephalus: significance and comparison with other forms of dementia.

This study was undertaken to identify findings on magnetic resonance (MR) imaging that might possibly differentiate among several dementia states in the elderly or predict response to shunt therapy in patients with normal-pressure hydrocephalus (NPH). The MR findings were retrospectively reviewed in 54 patients who were divided into four clinical categories: NPH (17 patients), obstructive hydrocephalus (eight patients), Alzheimer disease (eight patients), and non-Alzheimer dementia (21 patients). Three MR findings were evaluated in each case: increased periventricular (PVS) and white matter (WMS) signal on T2-weighted images, CSF flow void sign (CFVS) in the aqueduct, and corpus callosum thinning. Neither the PVS/WMS nor corpus callosum thinning patterns were useful for distinguishing among the four clinical groups. At low field strength, the absence of a marked or moderate CFVS, however, may militate against a diagnosis of NPH. All 17 patients with NPH underwent a shunt procedure after the MR study. A better response to shunt therapy occurred in patients without WMS and with more severe PVS.

Long-term prognosis after carotid artery occlusion

One hundred thirty eight patients with angiographi-cally proved carotid artery occlusion and minimal or no neurologic deficit were followed up for an average of 5 years. For patients 35 years old or over, the observed 5-year survival rate on an actuarial basis was 77% compared with an expected rate of 85% in a matched normal population. For patients 35 years old or over, the subsequent stroke rate was 3% per year, and two-thirds of the strokes were ipsilateral to the carotid artery occlusion. The observed stroke rate for all patients 35 years old or over was eight times the expected rate for a matched normal population. The relative risk of stroke was much greater in the younger patients with atherosclerotic carotid artery occlusion than in the older patients.

An Evaluation of the Quantitative and Radiation Features of a Scanning X-Ray Transverse Axial Tomograph: The EMI Scanner

Evaluation of the EMI Scanner, an x-ray transverse axial tomograph, has shown that the unit provides numerical values which are linearly related to the 73 keV attenuation coefficient values with an agreement of better than one half of one per cent. Precision of these determinations has also been shown to be 0.5%. Independence of spatial location and accurate resolution of objects as small as 6 mm have been demonstrated. An adjacency effect at a bone-brain matter interface was measured. Radiation exposures arc comparable to those received in many diagnostic roentgenologic procedures.

The primary angiographic findings in pituitary adenomas.

Angiographic findings in 41 cases of pituitary adenoma were analyzed to determine the alterations that were due to the tumor. Pathologic changes in the meningohypophyseal trunk were observed in all cases and in the pituitary capsular arteries in almost 88%. Abnormal tumor vascularity was visible in all cases, and the character of this “blush” was indicative of the gross characteristics of the tumor—solid, cystic, or degenerated. Angiography is the neuroradiologic study of choice in the diagnosis of sellar lesions and the use of pneumoencephalography is eliminated except in instances in which the angiographic findings are atypical or equivocal.

MYELOGRAPHIC EXAMINATION OF THE POSTERIOR FOSSA WITH POSITIVE CONTRAST MEDIUM.

The detection of correctable lesions at the craniospinal junction has always been a perplexing problem to the physician concerned with diseases of the nervous system. This is true because processes amenable to surgical attack, such as tumors, aneurysms, vascular anomalies, platybasia, basilar invagination, and the Arnold-Chiari malformation, often produce symptoms and signs identical with those of purely degenerative lesions in this region. These manifestations may include occipital headaches, neck pain, bizarre sensory disturbances, inco-ordination, spastic ataxic gait, nystagmus, tremor, or disturbance of sphincter control. To discover the correctable lesions, therefore, a number of patients with presumed multiple sclerosis, syringomyelia, amyotrophic lateral sclerosis, primary lateral sclerosis, or chronic encephalomyelitis must be aggressively subjected to neuroradiologic, electromyographic, and neurochemical diagnostic procedures. Malis (2), Mellins (3), and Mones and Werman (4, 5) have described nov...

Computed Tomography and Radionuclide Imaging in the Evaluation of Ischemic Stroke

One hundred forty-one patients with cerebral or cerebellar infarction were examined by computed tomography (CT) as soon after the ictus as possible. The examination was repeated in 7 days, and a radionuclide brain scan was performed. The overall detection rate for ischemic infarction was approximately equal for both techniques, ranging from 58% for radionuclide scanning to 66% for the delayed CT. Almost half of the supratentorial infarcts examined by CT on the day of the ictus were demonstrated. Mass effect was observed as early as the first day and as late as the 25th day.

Performance Evaluation and Quality Assurance of Computed Tomography Scanners, with Illustrations from the EMI, ACTA, and Delta Scanners

Performance evaluation of equipment for computed tomography (CT) involves the integration of: (a) establishing performance criteria; (b) designing and implementing test procedures; and (c) reconciling test results in terms of desired performance. Precision (noise), contrast scale, linearity, accuracy, spatial independence, spatial resolution, artifacts, reproducible performance, and patient exposure are several parameters discussed, as are problems of measurement with regard to non-water bath scanners. Performance and quality control tests for the ACTA, Delta, and EMI scanners are outlined. Guidance for the prospective purchaser of CT equipment is presented as a summary of the ideas discussed.