Assessment of arterial blood flow measurements by digital angiography

A system for computerized processing of video image series was utilized for the real-time digitization of arteriograms. There were 256 x 256 picture elements (pixels) per image with a resolution of 256 gray levels. Temporal changes in x-ray absorption at each pixel as induced by contrast media were computed for the extraction of regional blood flow parameters. Four steps of processing included: (a) vascular masking, (b) time parameter extraction, (c) segmentation of vessels, and (d) segmental volume and flow determinations. The results were displayed pictorially as angiographic parameter images. Measurement of the regional blood flow was tested at the abdominal arteries in nine pigs. Flow distribution values at the renal and iliac arteries were accurate within +/- 5% of the total abdominal aortic flow. The method may also be applicable to quantitative circulatory studies of the cerebral, pulmonary, and possibly, coronary arteries.