[Computer-aided image processing of digital subtraction angiographs of the pelvis-leg region]

Within a clinical study on possible regression of arteriosclerotic processes in humans i.v. DSA-images were made and objectively evaluated. For the first time the digital system Densitron 4 was used for this. The image processing nodes of contrast enhancement, gray-scale and color conversion and stenosis evaluation by density sums are demonstrated for two selected cases from 52 intravenous digital subtraction angiographies of the pelvis-leg region. The results show, that digital image processing can enhance information-relevant detail. The preprocessing of densitometric values accounts for the third dimension of the vessel in its morphologic description. Compared with subjective visual evaluation the digital image interpretation facilitates a much higher degree of detectability of small detail located near the vessel walls and a more objective and reproducible evaluation of the degree of stenosis.