COMPUTERIZED FLUOROSCOPY TECHNIQUES FOR NON-INVASIVE CARDIOVASCULAR IMAGING.

A number of methods for visualizing the cardiovascular system of dogs and humans in real time have been developed and are grouped under the heading computerized fluoroscopy. Such techniques provide images capable of high contrast sensitivity and moderate spatial resolution (approximately 1mm). A standard image intensifier-television chain used in connection with a specially constructed digital video image processor is capable of producing contrast enhanced difference images at rates up to 60/second. Such difference images can isolate small concentrations of iodine which have been administered intravenously through peripheral veins. Such noninvasive techniques have been used to visualize: 1) the carotid arteries and fine structures in dogs and humans at typical rates of 2 per second, and 2) the heart chambers of both dogs and humans at typical display rates of 15-60 per second. For such studies 0. 6-1. 0 gms (Iodine)/kg (body mass) have provided excellent visualization of the cardiac chamber dynamics.