Perfusion imaging by PET to assess stenosis significance

摘要: Quantification of coronary flow and reserve is an attractive concept to assess stenosis significance, because the ultimate severity a depends on reduced ability increase myocardial blood by vasodilation at arteriolar level [1]. By autoregulation follows demand, in other words, circulation remains constant with either decreased pressure or increased meet actual metabolic demand (Figure 1). Nevertheless, quantitative magnitude vasodilator inversely related increasing stenosis. The complexity this outlined Figure 2. autoregulatory capacity allows resting stay over wide range diameter stenoses but decreases gradually stenotic reduction 85% 90%, under conditions >90%. This relationship basic measurements for defining 2). In normal arteries can be 3 5 times periphereal bed, thus absolute reserve, defined as maximal stenosed artery devided same region, ranges from humans. With almost linearly severely exhausted does not even result any increase; hence, has minimal value one.