Showing papers on "Perfusion scanning published in 1975"

Human Cns Perfusion Scanning With 123L-Lodoantipyrine

Abstract: Regional perfusion scanning of the central nervous system requires lipophilic radionuclides that rapidly penetrate the intact blood brain barrier. The first compound of this type to be developed for human use is 123l-iodoantipyrine. 123l-iodoantipyrine rapidly crosses the blood brain barrier and is flow-limited in its delivery to the brain. This makes possible the CNS perfusion scanning of the human brain, thereby showing regional distribution of microcirculatory blood flow.

Peripheral vascular perfusion scanning. Correlation with the arteriogram and clinical assessment in the patient with peripheral vascular disease.

Abstract: Peripheral vascular perfusion scan during rest and reactive hyperemia does not necessarily offer the same information as the arteriogram or the clinical assessment of the peripheral pulses. The information obtained from the peripheral vascular perfusion scan offers potentially clinically useful information regarding the physiologic significance of various arterial lesions to the surgeon in selection of his therapeutic approach. The peripheral vascular perfusion scan uniquely and under varied physiologic conditions permits assessment of the effect of arterial disease on the distribution of perfusion within the extremity. The peripheral vascular perfusion scan is not in competition with, but is complementary to, arteriography and clinical assessment of the patient with peripheral vascular disease.

Multiple pulmonary arteriovenous fistulas demonstrated by dynamic radionuclide pulmonary perfusion scanning.

Abstract: Dynamic radionuclide perfusion scintigraphy performed with 99mTc-labeled microspheres was instrumental in establishing the diagnosis of multiple, small-vessel, pulmonary arteriovenous fistulas in a 14-month-old patient with cyanosis. Computer analysis of the sequential distribution of tagged microspheres in the pulmonary parenchyma normally demonstrates a curve that rises rapidly to a plateau as the particles microembolize. In the case reported here, the pulmonary flow curve rose rapidly to a maximum and then fell within 2 sec to a plateau of less than 50% of the maximum count, indicating that a large proportion of the microsophers passed through the pulmonary circulation. Conventional pulmonary contrast angiography did not demonstrate any intracardiac shunting but did confirm the presence of multiple pulmonary arteriovenous fistulas.

Limitations of Radionuclide Flow Studies in Bilateral Carotid Thrombosis

Abstract: Radionuclide angiography as a noninvasive procedure has become an important tool in the evaluation of cerebrovascular diseases. Determinations of arm-to-brain circulation times complemented by the transit times of the radionuclide bolus through the brain afford insight into the functional status of the vascular system of the brain. Delays in perfusion, asymmetries in appearance, and washout of the radionuclide material can be correlated with disease entities. However, as with many procedures elevated to the status of a screening test, the possibility of false-positive and false-negative results exists. Two cases of bilateral carotid occlusion are presented, showing normal or only delayed, fairly symmetrical brain perfusion. The appearance of the radionuclide flow in the neck in AP and lateral views gave no suggestion of the involved deficits. Even multiple-projection imaging might fail to demonstrate major vascular obstructions. However, attentive study of these projections might yield interesting evidence of unexpected collateral flow systems.

[Selective coronary perfusion scintigraphy. II. Abnormal coronary perfusion pattern (author's transl)].

Abstract: Integrated assessment of selective coronary angiorgrams and perfusion scintigrams of 86 patients with coronary-artery insufficiency revealed anatomical and topographical details which could not be achieved with one of these methods alone. Pathological perfusion patterns were quite different from normal ones. The functional effects of single, centrally located stenoses, of more peripheral and multiple narrowings, as well as of anastomoses and collaterals were adequately demonstrated by selective coronary perfusion scintigraphy and prevented diagnostic errors. It is, therefore, an additional aid in the diagnosis of coronary-artery disease.

The Influence of Ventricular Perfusion on Normal Brain

Abstract: The prognosis and final outcome in patients with severe head injuries is closely related, among other factors, to the level of increased intracranial pressure (ICP) caused by cerebral edema as well as to the severity of CSF lactacidosis. There exists evidence that a clearance of substances which accumulate in edematous tissue, i.e. proteins and lactate, without rising the ICP exerts a beneficial effect in such cases. Previous studies by other groups (4, 5) using a similar experimental technique but with small amounts of perfusion-volume were concerned with the influence of various concentrations of bicarbonate of the perfusion medium on the regulation mechanisms of cerebral blood flow (CBF). The present study was carried out to investigate the effect of a ventriculo-cisternal perfusion with a flow volume leading to a ten to twelve timefold exchange of the intraventricular cerebro-spinal fluid (CSF) volume on the normal cerebral blood flow.