目的 探讨基于非增强心脏磁共振（cardiac magnetic resonance imaging，CMR）的周长面积比（perimeter-area ratio，PAR）对慢性血栓栓塞性肺疾病（chronic pulmonary thromboembolism，CPTE）患者心室重构与风险分层中的价值。 方法 前瞻性纳入53例CPTE患者，包括37例慢性血栓栓塞性肺动脉高压（chronic thromboembolic pulmonary hypertension，CTEPH）患者和16例慢性血栓栓塞性疾病（chronic thromboembolic pulmonary disease，CTEPD）患者，同期招募53例性别、年龄匹配的健康受试者作为对照组。所有患者均在24 h内接受CMR及右心导管检查。计算并比较3组在舒张末期和收缩末期3个短轴层面的双心室PAR。采用受试者工作特征曲线评估诊断效能，并通过Spearman秩相关性检验探讨PAR与血流动力学间的相关性。 结果 与CTEPD组相比，CTEPH组右室（right ventricular，RV）PAR降低，尤以心尖部差异最为显著（P < 0.05）。心尖部PAR在CPTE的识别及其亚型鉴别中均表现出良好的诊断效能，AUC值范围0.872 ~ 0.990，并普遍具有较高的敏感度与特异度。RVPAR与负荷指标呈负相关，与灌注/输出指标呈正相关（均P < 0.05）。 结论 基于CMR的PAR可敏感捕捉CPTE患者右心室的微观重构变化，可作为评估疾病严重程度与风险分层的潜在无创生物标志物，同时也提示心尖是右心室适应性变化最敏感的区域。

Objective This study aims to investigate the value of the perimeter-area ratio （PAR） derived from non-contrast cardiac magnetic resonance （CMR） imaging in assessing ventricular remodeling and risk stratification in patients with chronic pulmonary thromboembolism （CPTE）. Methods A total of 53 patients with CPTE were prospectively enrolled，including 16 with chronic thromboembolic pulmonary disease （CTEPD） and 37 with chronic thromboembolic pulmonary hypertension （CTEPH）. Additionally，53 age- and sex-matched healthy volunteers were recruited as controls. All patients underwent CMR and right heart catheterization within 24 hours. Biventricular PAR values were calculated and compared among the three groups at three short-axis levels on end-diastolic and end-systolic cine images. Diagnostic performance was assessed using receiver operating characteristic curve analysis，and associations between PAR and hemodynamic parameters were examined using Spearman’s correlation. Results Compared with CTEPD patients，right ventricular （RV） PAR was significantly lower in CTEPH patients，with the most pronounced difference observed at the apical level （P < 0.05）. At this level，RV-PAR demonstrated excellent diagnostic performance in identifying CPTE and distinguishing its subtypes，with area under the curve （AUC） values ranging from 0.872 to 0.990，along with high sensitivity and specificity. RV-PAR was negatively correlated with afterload indices and positively correlated with perfusion and output parameters （all P < 0.05）. Conclusions CMR-derived PAR sensitively captures microstructural remodeling of the right ventricle in CPTE patients， serving as a potential non-invasive biomarker for disease severity assessment and risk stratification. Notably，the cardiac apex emerges as the most sensitive region for adaptive changes in the right ventricle.