TY - JOUR T1 - ECG-gated dynamic myocardial PET with 15O-H2O estimated higher perfusable tissue fraction in the ischemic myocardial lesions after revascularization: compared with conventional non-gated PET JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 170 LP - 170 VL - 60 IS - supplement 1 AU - Chietsugu Katoh AU - Shinya Kato AU - Tadao Aikawa AU - Masanao Naya AU - Keiichi Magota AU - Osamu Manabe AU - Tohru Shiga Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/170.abstract N2 - 170Objectives: Dynamic myocardial PET study with 15O-H2O enables the quantification of regional myocardial perfusable tissue fraction (PTF). However, the left ventricular (LV) wall motion artifact decreases the accuracy of the value. Then, we performed electro-cardiogram (ECG) gated dynamic myocardial PET with 15O-H2O and developed the programs for accurate estimation of the PTF in the ischemic myocardial lesions after revascularization. Methods: Thirty patients (68±12 years old, male 28, female 2) with ischemic heart disease were employed. They all had percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Before and after the revascularization, list mode 3D PET data were acquired with ECG signals using Philips Gemini TF64. For each scan, 500MBq of 15O-H2O was infused slowly for 2min, dynamic data were scanned for 6min. Using list mode PET data and ECG signals, both non-gated dynamic images and ECG-gated end-diastolic dynamic images were reconstructed. Coronary arteriograms were also carried out for each patient before and after revascularization, totally 77 ischemic segments with over 50% increase of luminal diameter after revascularization were evaluated. A whole myocardial ROI was positioned and divided into 17 segments. The regional myocardial ROI curve R(t) and left ventricular ROI curve LV(t) were calculated, the perfusable tissue fraction PTF, spillover fraction Va and myocardial blood flow MBF in each myocardial ROI were estimated by these curves with single-tissue compartment model analysis with non-linear least squared method as following equations; R(t) = PTF Ct(t) + Va Ca(t), LV(t) = b Ca(t) + (1-b) Ct(t), dCt(t) / dt = MBF Ca(t) - (MBF/p) Ct(t), where, Ca(t) and Ct(t) were true arterial and myocardial tissue curves, parameters p and b were partition coefficient in the myocardium and recovery coefficient of the LV ROI counts, respectively. Both non-gated dynamic images and ECG-gated end-diastolic dynamic images were analyzed. The environment for these analyses were developed with Visual C++ and C#. Results: In the ischemic myocardial segments before revascularization, PTF values with ECG-gated PET were estimated significantly lower (0.67±0.13(ml/ml)) than those with non-gated PET (0.70±0.12(ml/ml), p<0.02). However, after revascularization, ECG-gated PET yielded significantly higher PTF (0.75±0.09 (ml/ml)) than those with non-gated PET (0.73±0.08(ml/ml), p<0.01). Increase ratio of PTF after revascularization from ECG-gated PET were significantly higher (1.14±0.19) than those from non-gated PET (1.04±0.14, p<0.001). Conclusions: We developed a technique to estimate the perfusable tissue fraction in the ischemic myocardial lesion before and after revascularization using ECG-gated dynamic myocardial PET with 15O-H2O. ECG-gated PET enabled to suppress the LV wall motion artifact, and could estimate the increase of perfusable tissue in the ischemic myocardial lesion after revascularization better than conventional non-gated myocardial dynamic PET. ER -