[The scope and limitations in the demonstration of vessels by angiotomography; their relationship with contrast and size and between detail and direction of cut (author's transl)].

Experiments with models and post mortem angiograms have shown that the supposed advantages of angiotomography, such as determination of the depth of vessels, cannot be achieved with accuracy if there is repeated change in direction of the vessels. Blurring of superimposed vessels depends not only on their contrast and calibre, but also on their alignment in relationship to the direction of blurring. Vessels running in the direction of blurring produce undesirable shadows through a considerable depth, whereas vessels running across the direction of blurring are rapidly blurred if not in the selected plane. The demonstration of vessels running at right angles to the direction of blurring may at times be very difficult with simultaneous tomography. The clinical significance of this finding is pointed out.