Key points are not available for this paper at this time.
The assessment or measurement of arterial narrowings should allow the quantitative prediction of a reduced perfusion distal to the lesion. Certainly the degree of relative diameter narrowing is a basic parameter herefore which can directly be measured in the angiogram. The visual estimation is quite erroneous, even if only the maximal diameter reduction has to be found. The determination of other quantities like the stenotic area reduction requires at least some calculation on the computer or can only be done if several reference measures and thresholds are taken into account. This is the case if the sclerotic volume reduction /2/ is to be calculated slice by slice over a certain length, perhaps from two projections and discriminating contrast medium from calcium shadows /12/. If hemodynamic conclusions are to be drawn from the evaluations, the magnification factor is also needed /10/ and a dynamic flow measurement should be done for final cross-checking /3/.
Barth et al. (1982) studied this question.