Study of cerebral flow with radionuclide: 99mTc-pertechnetate transit times and curves

The transit of intravenously injected 99mTc-pertechnetate in the cerebrovascular tree can be monitored in patients in a supine position by means of a computer-assisted gamma-camera. When programmed properly, time-activity curves of the tracer in the region to be studied can be displayed, i.e. internal carotid arteries, brain hemispheres, etc. The application of the modified gamma function to these curves is employed in order to more accurately define the transit and transfer times in this region. Thirtyseven patients with cerebrovascular disturbances were examined. In most cases asymmetrical cerebral perfusion and a significant difference between right and left transit and/or transfer times were noted.