Figure 5c.

Use of CFR to identify disease not visible at perfusion PET in a 61-year-old man who was referred for evaluation of chest pain. (a, b) Stress-rest myocardial perfusion PET scans (a) demonstrate a small reversible perfusion defect involving the left ventricular apex and inferoapical segments, a finding that is consistent with single-vessel ischemia in the distal left anterior descending coronary artery territory. Although PET helped correctly identify the patient as having obstructive CAD, it led to severe underestimation of the amount of myocardium at risk. However, quantitative CFR (b) was markedly impaired in all vascular territories (normal CFR >2), a finding that is consistent with extensive ischemic myocardium. LAD = left anterior descending artery, LCX = left circumflex artery, RCA = right coronary artery. (c, d) Left anterior oblique coronary angiograms (d, caudal view) demonstrate a complex plaque causing 70% stenosis involving the distal left main, proximal LAD, and LCX arteries (arrowheads). The right coronary artery had nonobstructive atherosclerosis.