[Resolving power of digital subtraction angiography (DSA). Measurements of opacification with different blood vessel calibers and constrictions in relation to contrast media concentration].

The demonstration of contrast-filled vessels by means of digital subtraction angiography has already proved a valuable clinical method (1 to 14). The present paper provides data on measured opacification as related to vessel calibre and contrast concentration. It is further shown in which degree narrowing of vessels can be ascertained dependent on vessel size and contrast concentration. Finally, the spatial resolution of the method has been investigated by using phantoms. It was shown that the resolution depends on the direction of the vessels within the projected area.