Dynamic intramyocardial blood volume: evaluation with a radiological opaque marker method.

In this study the change of intramyocardial blood volume within one cardiac cycle was deduced from the time sequence of the volume delineated by radiopaque markers attached to the left ventricular wall. These data were compared with the change in the volume of the same region of myocardium estimated from the change in angiographic opacification of the heart wall. Five dogs were anesthetized, and four pairs of 2-mm-diameter lead beads were attached to the epicardial and endocardial regions. Two scans using the dynamic spatial reconstructor (a high-speed computed tomographic scanner) were performed during aortograms, one under control conditions and the other during adenosine infusion. The results have shown that the increases of myocardial volume defined by the beads (delta Vbead, % of volume at control) were comparable to the increase of intramyocardial blood volumes estimated by the increase in wall opacity (delta Vblood, % of muscle); delta Vblood = 0.93 delta Vbead + 1.54%; r = 0.987.