Purpose To observe the right ventricle and left ventricle blood pool T2 map in chronic thromboembolic pulmonary hypertension(CTEPH)and healthy controls,and to analyze the value of T2 mapping technique in evaluating CTEPH.Materials and Methods A total of 42 patients with CTEPH and 42 healthy volunteers had been prospectively recruited from January 2020 to January 2022 in China-Japan Friendship Hospital.All CTEPH patients underwent cardiac magnetic resonance with T2 mapping and right heart catheterization.Cardiac magnetic resonance was performed on healthy controls.Diastolic T2 mapping was performed in cardiac magnetic resonance,and then the ratio of right ventricular to left ventricular T2 values(RVT2/LVT2)between the CTEPH group and the healthy group was calculated and compared.Meanwhile,the correlation between RVT2/LVT2 and hemodynamic parameters in the CTEPH group was analyzed.Results RVT2/LVT2 in the CTEPH group was significantly lower than that in the healthy group(0.74±0.16 vs.0.86±0.12;t=3.673,P<0.001).RVT2/LVT2 in CTEPH group was negatively correlated with pulmonary vascular resistance(r=-0.534,P<0.001);while it was positively correlated with cardiac index,right atrium oxygen saturation,right ventricle oxygen saturation and pulmonary arteries oxygen saturation(r=0.600,0.603,0.648,0.582,P<0.001).Conclusion RVT2/LVT2 in the CTEPH group is positively correlated with right cardiac oxygen saturation and negatively correlated with pulmonary vascular resistance.T2 mapping may be a noninvasive evaluation of hemodynamics in CTEPH.