Objective

To investigate flow-related parameters in pulmonary arteries of patients with pulmonary arterial hypertension (PAH).

Materials and methods

Eleven PAH patients and twelve control participants were recruited. PAH and controls had similar age and gender distribution. 2D phase-contrast MRI (PC-MRI) was performed in the main, right, and left pulmonary artery (MPA, RPA, and LPA). The flow velocity, wall shear stress (WSS), and oscillatory shear index (OSI) were measured.

Results

PAH patients displayed prolonged acceleration time (T_acce) and increased ratio of flow change to acceleration volume in pulmonary arteries (both P < 0.001). The temporally averaged WSS values of MPA, RPA, and LPA in PAH patients were significantly lower than those of control participants (P < 0.001). The OSI in the pulmonary arteries was higher in PAH patients than control participants (P < 0.05). The ROC analysis indicated the ratio of maximum flow change to acceleration volume, WSS, and T_acce exhibited sufficient sensitivity and specificity to detect patients with PAH. The WSS demonstrated strong correlations with T_acce and the ratio value in the two groups (R² = 0.78–0.96).

Conclusions

We used a clinically feasible 2D PC-MRI sequence with a reasonable scanning time to compute aforementioned indices. The quantitative parameters provided sufficient information to differentiate PAH patients from control participants.

中文翻译：

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相衬磁共振成像分析肺动脉高压患者的血流动力学参数和肺动脉壁切应力

客观的

调查肺动脉高压（PAH）患者肺动脉血流相关参数。

材料和方法

招募了11名PAH患者和12名对照参与者。PAH和对照组的年龄和性别分布相似。在主，右和左肺动脉（MPA，RPA和LPA）中进行了2D相衬MRI（PC-MRI）。测量了流速，壁切应力（WSS）和振荡剪切指数（OSI）。

结果

PAH患者显示出延长的加速时间（T _acce）和增加的流量变化与肺动脉加速体积的比率（均P  <0.001）。PAH患者的MPA，RPA和LPA的时间平均WSS值显着低于对照组参与者（P  <0.001）。PAH患者的肺动脉OSI高于对照组（P  <0.05）。ROC分析表明最大流量变化与加速量之比，WSS和T _acce表现出足够的灵敏度和特异性来检测PAH患者。WSS证明与T _acce有很强的相关性两组的比值（R ²  = 0.78–0.96）。

结论

我们使用临床上可行的二维PC-MRI序列，并在合理的扫描时间内计算上述指标。定量参数提供了足够的信息来区分PAH患者和对照组。