Manfred Boehnke

The capacity for computed tomography diagnosis of cerebral infarction. An experimental study in the nonhuman primate.

The characteristic serial CT scan appearance of cerebral infarction created by embolization of the middle cerebral artery in the nonhuman primate (10 baboons) is defined. The earliest CT changes are noted by 12 to 24 hours and include generalized ventricular enlargement and a focal region of decreased absorption in the opercula-basal ganglia region. The area of diminished brain absorption is better circumscribed and of lower attenuation coefficient with increasing chronicity. Distinct hydrocephalus, unilateral exophthalmos and ventricular displacement occurred with increased intracranial pressure. Little additional diagnostic information was obtained via intravenous enhancement and care should be taken as mild enhancement may obscure an area of abnormality.

CT scan in intraventricular hemorrhage: correlation of clinical findings with computerized tomographic scans of the brain.

Twenty-three adults who had evidence of intraventricular hemorrhage were identified, and their charts were reviewed. Thirteen patients died and 10 survived. Eleven of the 13 who died were hypertensive. All had severe neurological deficit and evidence of brain stem dysfunction at the time of admission and progressed rapidly to coma and death. Two of the survivors had periventricular arteriovenous malformations. They presented neurologically intact and remained so. The other eight survivors had a distinct clinical course. They presented with focal deficits and abnormalities of mental status. These persisted, and at follow-up 3 to 20 months later they all had profound deficits of recent memory and intellect, and none was capable of daily self-care. Computerized tomographic (CT) scans were not useful in predicting outcome. The presence of parenchymal clot, multiple chamber involvement, 3rd ventricular involvement, ventriculomegaly, and midline shift were seen in all groups. Illustrative examples are presented.

Small-bowel obstruction caused by intraluminal migration of prosthetic grafts.

Two patients who had undergone prosthetic grafting in the venous system presented with small-bowel obstruction. The first had undergone mesocaval shunting with a Dacron graft and the second, replacement of the inferior vena cava with a polytetrafluoroethylene graft after an extensive resection of retroperitoneal tumor. In both instances the grafts were within the lumen of the small bowel, causing a mechanical obstruction. No evidence of retroperitoneal bleeding subsequent to detachment of the grafts was noted.

Cranial computed tomography in the baboon: normal anatomy.

A simple, reliable, reproducible technique for performing CT scans on baboons is described. The normal morphologic appearance in 12 nonhuman primate (Papio cynocephalusl anubis) brains as defined by CT is correlated with the normal gross pathologic findings on postmortem examination. The orbital contents are also displayed with clarity equivalent to that obtained in man.

Splenic Vein Thrombosis: Case Report

Splenic Vein Thrombosis: Case Report The patient is a 68 year old white female, who was re-admitted to Montefiore Hospital following her second episode of hematemesis in a six week period. During her first admission, esophageal varices were noted endoscopically ; this finding was confirmed at the time of her second admission. The patient had an eight year history of adult onset diabetes. There was no history of alcoholism, liver disease, trauma or abdominal pain. Physical examination revealed a white female in no acute distress. Her blood pressure

High Resolution Mapping of Cerebral Blood Flow in Alzheimer’s Disease

An increased knowledge of local CNS blood flow patterns in dementia may ultimately prove highly significant in the diagnosis and in the understanding of pathophysiologic states of this related group of diseases. Since an important prevalent condition, multi-infarct dementia (MID), has cerebral circulatory implications and must be differentiated from other dementias, including Alzheimer’s type (AD), it is obvious that elucidation of cerebral blood flow (CBF) changes will be important in its differentiation. Other, perhaps more subtle, circulatory changes may occur in the other dementias which will be of equal or greater importance. Reduced CBF having a distribution similar to that of the neuropathologic changes has been described in AD [1]. The advent of a method for local blood flow measurement which is noninvasive, employing a nontoxic, respirable indicator (stable xenon), which has anatomical resolving power greater than most other methods and approaching that of computed axial tomography (CT), and which is readily adapted to imaging techniques of presentation, has provided the means for a detailed study of local blood flow in the dementias, Alzheimer’s in particular. Currently, at the University of Pittsburgh, we are engaged in a multidisciplinary, longitudinal study of 300 subjects including 200 with a presumptive diagnosis of AD and 100 age-matched controls. The stable xenon local CBF method, developed in our laboratories [2–5], is employed for the study of several aspects of AD and related dementias.

Comparative cranial CT enhancement in the normal primate.

The application of intravenous, intrathecal, and inhalation enhancement techniques to the CT evaluation of the nonhuman primate (Papio cynocephalus/anubis) is described. The falx cerebri cortical vasculature, vein of Galen, straight sinus and tentorium cerebelli were defined with intravenous enhancement. Intrathecal CT enhancement with air was limited by distortion in cerebrospinal fluid spaces. Intrathecal CT enhancement using a low dose of metrizamide accurately delineated the subarachnoid spaces and the brain substance they surrounded with minimal morbidity. Symmetrical brain enhancement (perfusion) was prominent following inhalation CT enhancement; the degree of enhancement correlated with the estimated xenon concentration in the bloodstream. In addition, by performing repeated CT scans during the clearance of xenon from the brain, an approximate analysis of regional cerebral blood flow was obtained.

Ophthalmologic applications of computed tomography in nonhuman primates.

The orbital contents of 28 baboons are defined by computed tomography (CT), which provides a simple, reliable, reproducible, and accurate technique for the experimental investigation of the orbit of the nonhuman primate. This method is applied to the diagnosis of exophthalmos. The suprasellar and other basal subarachnoid cisterns are precisely delineated using intrathecal enhancement prior to CT imaging (metrizamide CT cisternog-raphy).