@misc{oai:repo.qst.go.jp:00066304,
 author = {Yoshinaga, Keiichiro and Tomiyama, Yuuki and Hiroshi, Ohira and Manabe, Osamu and Tsujino, Ichizo and Katoh, Chietsugu and Masaharu, Nishimura and 吉永 恵一郎},
 month = {Jun},
 note = {OBJECTIVES: Elevated pulmonary arterial pressure (PAP) induces pulmonary artery remodeling and may have an impact on lung perfusion in patients with pulmonary hypertension (PH). Quantitative pulmonary blood flow (PBF) evaluation may be a sensitive approach to assessing pulmonary perfusion abnormality. However, this approach has not been studied in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH). Using O-15-labeled water PET, we sought to evaluate whether there was a difference in lung perfusion between the two subgroups with PH. 
METHODS: Twenty-seven patients with WHO functional class II or III due to 16 PAH or 11 CTEPH and 7 controls prospectively underwent dynamic O-15-labeled water PET at rest. All CTEPH patients showed multiple perfusion defects in both lungs according to a 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 obtained from the right ventricle (RV) cavity. Regions of interest were created on bilateral lung using transmission scan data.
RESULTS: The mean PAP (mPAP) associated with both CTEPH and PAH was similar (CTEPH 36.7±11.6 mmHg vs. PAH 42.3±14.4 mmHg, P=0.30). There was no significant difference in whole left ventricular (LV) MBF among the CTEPH, PAH and controls (CTEPH 0.87±0.24 mL/g/min, PAH 0.84±0.18 mL/g/min vs. control 0.76±0.11 mL/g/min, P=0.71). CTEPH patients showed significantly lower left PBF compared to that in either PAH (180.5±27.2 mL/100mL of lung/min vs. 225.6±41.0 mL/ 100mL of lung/min, P=0.0043) or control (180.5±27.2 mL/100mL of lung/min vs. 224.7±42.6 mL/ 100mL of lung/min, P=0.020). In contrast, PAH showed similar PBF compared to that of control (P=0.96). Similarly, CTEPH showed reduced right PBF compared to that of PAH (131.9±27.2 mL/100mL of lung/min vs. 168.5±32.7 mL/ 100mL of lung/min, P=0.0029) and controls (131.9±27.2 mL/100mL of lung/min vs. 166.1±29.0 mL/ 100mL of lung/min, P=0.020). There was also no significant difference in right PBF between the PAH and control (P=0.86). Whole lung PBF did not correlate with mPAP (R=0.09, P=0.67). 
CONCLUSION: CTEPH patients showed preserved rest MBF similar to that of PAH patients. In contrast, bilateral PBF of CTEPH patients was reduced in comparison with that of PAH patients. Even with similar mPAP, CTEPH patients had significantly lower bilateral PBF than did PAH patients. Given the recent successes of catheter-based or surgical revascularization for CTEPH, quantitative PBF assessment using O-15-labeled-water PET may also be useful in evaluating emerging medical and invasive revascularization treatments for CTEPH., 63rd Society of Nuclear Medicine and Molecular Imaging( 第63回米国核医学・分子イメージング学会学術集会)},
 title = {Assessment of reduction in quantitative pulmonary blood flow using O-15-labeled water PET in patients with chronic thromboembolic pulmonary hypertension  1},
 year = {2016}
}