Investigation into Bilateral Distribution of Cerebral Blood Flow using a Multidetector Scintillating System

Abstract

The thesis details studies carried out on the blood flow in the human brain following an abrupt intravenous injection of non-diffusible radioisotope. Intended to be an adjunct to the static brafnin the diagnosis of cerebro-vascular disease, such dynamic studies have been in routine clinical use for many years, In the majority of cases the gamma-camera has been used as the detection apparatus, The relatively high cost of these instruments and their disadvantage of having a mono=planar field of view limits their use, In order to provide an inexpensive solution, a multidetector scintillation system has been designed and fabricated using readily available components, Suitable multihole collimators were made using a novel folding technique with strips of lead sheets, Two converging collimators were made to examine the carotid arteries while two parallel-hole collimators were used to monitor large blocks of tissue over both cerebral hemispheres, Data from all four detectors were sampled immediately following an intravenous injection of Om and stored in a mini-computer. lesults were then displayed on an X-Y plotter to enable visual comparison of the transit curves to be carried out. A total of 90 patients were examined and 37 were found to have abnormal signs. 32 of these were confirmed by other procedures such as static scan, section scan, computed tomography, angiography or surgery. These figures are in accordance with results published by previous workers who mainly used ganma-cameras. There was no indication that the multidetector system was superior to the gamma-camera in the detection of cerebro-vascular disease but the relatively low cost of the system and its simplicity in use make it a worthwhile instrument to have in departments where there is no gamma-camera available.