The quantitative analysis of blood flow within central and peripheral blood vessels has attracted more and more interest, for with the rapid developments in vascular surgery and the introduction of percutaneous transluminal angioplasty, it is becom ing increasingly important to be able to measure regional blood flow in man. In clinical radiology, angiography has been used predominantly from the point of view of its morphological applications. However, theoretically angiography may also be regarded as a specific application of indicator-dilution measurements of blood flow. The indicator is...