Abstract
1443
Purpose: Myocardial perfusion PET has the ability to quantitatively assess regional myocardial perfusion. However, myocardial perfusion is rarely compared before and after revascularization.Coronary flow reserve (CFR) ratio is the value of relative analysis and has clinical usefulness of detecting regional coronary artery disease (CAD).The purpose of this study was to assess regional quantitative myocardial perfusion after successful percutaneous revascularization in patients with CAD using CFR ratio on N-13 ammonia PET. Materials and Methods: We assessed 19 patients (70±10 years old, 17 males) with CAD who underwent stress/rest N-13 ammonia PET before percutaneous coronary intervention (PCI). In follow-up coronary angiography and PET (PET interval: 256±43 days), all patients had no restenosis of treated vessels and showed successful percutaneous revascularization. Myocardial blood flow (MBF) was calculated automatically using quantitative PET software and CFR was calculated as the ratio of stress-to-rest MBF in the major coronary territories. CFR ratio was defined as the ratio of per-vessel CFR to maximum CFR in a standard 17-segment model. All quantitative valueswere compared for before and after PCI. Results: PCI was performed on 21 of 57 vessels. Allquantitative values (Stress MBF, CFR and CFR ratio) with reperfused vessels were significantly higher after PCI than before PCI (2.16±0.51 vs. 1.57±0.55 ml/min/g; P<0.01, 2.56±0.76 vs. 1.85±0.61;P<0.01 and 0.84±0.07 vs. 0.65±0.11; P<0.01, respectively). Regional stress MBF decreased in 1 case and CFR decreased in another. In the former, stress MBF decreased in all territories and diffuse CFR decreased in the latter due to an increase in resting blood flow. CFR ratio increased all reperfused vessels. Conclusion: CFR ration on N-13 ammonia PET was useful in the assessment of improvement in regional quantitative myocardial perfusion after coronary revascularization. It was required to be careful assessment in patients with diffuse decreases in coronary perfusion or reserve.