Digital venous subtraction angiography makes it possible to obtain satisfactory images of the pulmonary vessels and thus to evaluate changes in the segmental and subsegmental arteries caused by pulmonary embolism. Morphologic as well as functional images can be produced in the course of a single examination. Semi-quantitative information about the vessels under examination as compared with the corresponding contralateral vessels is thus achieved. This procedure is valuable both in primary diagnosis and in subsequent repeat examinations after treatment.