Recent developments of cardiac digital radiography.

Digitization in cardiovascular radiology is on the verge of its realization. Since its introduction digital subtraction angiography (DSA) is gradually replacing conventional angiography in several areas of the body. The initial tendency to avoid the arterial catheterization by intravenous injection is somewhat reversed in favor of smaller intraarterial amounts of contrast medium injected through smaller catheters at reduced rates. However, left ventriculography by intravenous route has gained widespread acceptance at rest and with exercise: motion artifacts are less crucial for ventriculography than for small arteries, in which the same motion artifacts cause a more important relative deterioration of the image, so that it has to be corrected by pixel shift. DSA is only the first step towards functional imaging, where time and other parameters are condensed in one single color coded picture. Biharmonic Fourier analysis for quantitative analysis of regional left ventricular contraction and relaxation and digital coronary radiography for evaluation of contrast progression in the coronary circulation are two areas of cardiology where parametric imaging can help to detect functional abnormalities, especially in coronary heart disease.