[Videometry and videodensitometry: possibilities within the scope of clinical angiocardiography]

Videometry and videodensitometry was developed more than 20 years ago by the groups of E. H. Wood in Rochester, New York, USA and P. H. Heintzen in Kiel, West Germany. These techniques allow the extraction of quantitative parameters such as dimensions and volumes (videometry) and the concentration and distribution of contrast material (videodensitometry) from videoangiograms. Whereas videometric techniques have, in between, been implemented world-wide into clinical practice (e.g., for geometric measurement of heart chamber volume or the quantitative assessment of coronary morphology), videodensitometry has still been restricted to a small number of laboratories, mainly due to the technical requirements. Videodensitometry, however, offers an on-line frame-to-frame analysis of left and right ventricular volumes throughout the cardiac cycle, the measurement of valvular regurgitant fraction, the estimation of intracardiac shunts, as well as the measurement of blood flow and velocity in coronary arteries and the assessment of changes in myocardial perfusion due to interventions form clinical videoangiograms. Since the basic principles of these techniques can easily be applied to digital image processing, videodensitometry has gained new interest in a time of increasing distribution of digital cardiac imaging.