부산대학교 도서관

Introduction: Positron emission tomography (PET) myocardial perfusion imaging with [15O]water accurately detects ischemic coronary artery disease (CAD). Reduced exchange of water in the areas of infarction and scar lead to reduction in perfusable tissue fraction (PTF) and resting myocardial blood flow (MBF). We evaluated accuracy of regional PTF and resting MBF as markers of viability in a pig model of chronic myocardial infarction (MI). Methods: Surgical (n=17) or catheter based (n=5) occlusion of the proximal LAD was performed in 22 pigs. After 2 to 12 weeks, anesthetized pigs underwent rest [15O]water PET perfusion study with Discovery 690 hybrid PET/CT scanner and regional MBF and PTF were measured with Carimas software using standard 17 segment model. Segmental MBF and PTF They were compared with volume fraction of MI in matched segments as assessed by triphenyl tetrazolium chloride (TTC) staining of LV slices. Results: Based on TTC staining, segmental volume fraction of infarction was categorized as 0 % in 158 segments, 1-25 % in 64 segments, 26-50 % in 40 segments, 51-75 % in 29 segments and > 75 % in 41 segments. Segmental absolute and relative MBF as well as PTF gradually lowered with increasing volume fraction of MI (Figure). ROC analysis showed AUC of 0.81 with both relative MBF and PTF for the detection of viable myocardium defined as the segments with infarct volume fraction of ≤ 50 %. Relative MBF ≥ 49 % and PTF ≥ 67 % were the optimal cut-off values. Relative MBF showed sensitivity of 93 %, specificity of 56 % and accuracy of 86 %. PTF was more specific (71 %), but slightly less sensitive (81 %) and accurate (79 %) than relative MBF. Conclusions: In conclusion, our results indicate that resting MBF and PTF based on [15O]water PET perfusion imaging may both be useful for the assessment of myocardial viability in the setting of chronic MI. [ABSTRACT FROM AUTHOR]