@misc{oai:repo.qst.go.jp:00071733, author = {Yoshinaga, Keiichiro and Tomiyama, Yuuki and Tsujino, Ichizo and Ohira, Hiroshi and Manabe, Osamu and Katoh, Chietsugu and Nishimura, Masaharu and Tamaki, Nagara and 吉永 恵一郎}, month = {Jun}, note = {Background: Absolute pulmonary blood flow (PBF) estimation may be a sensitive approach to evaluate lung perfusion. However, this approach has not been studied in patients with chronic thromboembolic pulmonary hypertension (CTEPH). The purpose of the present study was to evaluate bilateral PBF in CTEPH patients using O-15-labeled water PET. Methods: Eleven patients with CTEPH (age 60.814.6 years, mean pulmonary artery pressure (mPAP): 35.49.3 mmHg, pulmonary vascular resistance: 7.152.79 WU) and 7 healthy controls (age 29.79.1 years) underwent dynamic O-15 water PET at rest. All CTEPH patients showed multiple perfusion defects in both lungs using Tc-99m macroaggregated human serum albumin lung scan. Dynamic O-15 water PET was used to simultaneously measure bilateral PBF and myocardial blood flow (MBF). The input function was derived from the right ventricle (RV) cavity. Region of interest were made on bilateral lung using transmission data. Results: There was no significant difference in whole LV MBF between the CTEPH and controls (0.880.24 vs. 0.760.11 mL/g/min, P=0.25). In contrast, CTEPH patients showed significantly lower left (180.527.2 vs. 224.742.6 mL/ 100mL of lung/min, P=0.015) and right PBF (131.122.1 vs. 166.129.0 mL/ 100mL of lung/min, P=0.012) compared to that in control. PBF did not correlate with mPAP (R=0.15, P=0.65). Conclusions: CTEPH patients showed preserved rest MBF, but reduced quantitative bilateral PBF. Addition of the quantitative PBF assessment using PET to the current imaging modalities may enable further understanding of the pathophysiology and may be better evaluation of the emerging medical and invasive treatments of CTEPH., 62nd Society of Nuclear Medicine and Molecular Imaging}, title = {Reduced Absolute Bilateral Pulmonary Blood Flow using O-15 labeled water PET in Patients with Chronic Thromboembolic Pulmonary Hypertension}, year = {2015} }