Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Nelson Basement MRI 110, 600 N Wolfe St, Baltimore, MD 21287, USA.
Radiology. 2012 Jun;263(3):678-87. doi: 10.1148/radiol.12111001. Epub 2012 Apr 16.
To prospectively compare contrast material-enhanced (CE) magnetic resonance (MR) imaging-derived right-to-left ventricle pulmonary transit time (PTT), left ventricular (LV) full width at half maximum (FWHM), and LV time to peak (TTP) between patients with pulmonary arterial hypertension (PAH) and healthy volunteers and to correlate these measurements with survival markers in patients with PAH.
This HIPAA-compliant study received institutional review board approval. Written informed consent was obtained from all participants. Forty-three patients (32 with PAH [29 women; median age, 55.4 years], 11 with scleroderma but not PAH [seven women; median age, 58.9 years]) underwent right-sided heart catheterization and 3-T CE cardiac MR imaging. Eighteen age- and sex-matched healthy control subjects (12 women; median age, 51.7 years) underwent only CE MR imaging. A short-axis saturation-recovery gradient-echo section was acquired in the basal third of both ventricles, and right-to-left-ventricle PTT, LV FWHM, and LV TTP were calculated. Statistical analysis included Kruskal-Wallis test, Wilcoxon rank sum test, Spearman correlation coefficient, multiple linear regression analysis, and Lin correlation coefficient analysis.
Patients had significantly longer PTT (median, 8.2 seconds; 25th-75th percentile, 6.9-9.9 seconds), FWHM (median, 8.2 seconds; 25th-75th percentile, 5.7-11.4 seconds), and TTP (median, 4.8 seconds; 25th-75th percentile, 3.9-6.5 seconds) than did control subjects (median, 6.4 seconds; 25th-75th percentile, 5.7-7.1 seconds; median, 5.2 seconds; 25th-75th percentile, 4.1-6.1 seconds; median, 3.2 seconds; 25th-75th percentile, 2.8-3.8 seconds, respectively; P < .01 for each) and subjects with scleroderma but not PAH (median, 6.5 seconds; 25th-75th percentile, 5.6-7.0 seconds; median, 5.0 seconds; 25th-75th percentile, 4.0-7.3 seconds; median, 3.6 seconds; 25th-75th percentile, 2.7-4.0 seconds, respectively; P < .02 for each). PTT, LV FWHM, and LV TTP correlated with pulmonary vascular resistance index (P < .01), right ventricular stroke volume index (P ≤ .01), and pulmonary artery capacitance (P ≤ .02). In multiple linear regression models, PTT, FWHM, and TTP were associated with mean pulmonary arterial pressure and cardiac index.
CE MR-derived PTT, LV FWHM, and LV TTP are noninvasive compound markers of pulmonary hemodynamics and cardiac function in patients with PAH. Their predictive value for patient outcome warrants further investigation.
前瞻性比较肺动脉高压（PAH）患者与健康志愿者之间对比增强（CE）磁共振（MR）成像衍生的右至左心室肺通过时间（PTT）、左心室（LV）半最大值全宽（FWHM）和 LV 达峰时间（TTP），并将这些测量值与 PAH 患者的生存标志物相关联。
本项符合 HIPAA 规定的研究获得了机构审查委员会的批准。所有参与者均签署了书面知情同意书。43 名患者（32 名 PAH 患者[29 名女性；中位年龄，55.4 岁]，11 名硬皮病但无 PAH 患者[7 名女性；中位年龄，58.9 岁]）接受了右侧心导管检查和 3-T CE 心脏 MR 成像。18 名年龄和性别匹配的健康对照组受试者（12 名女性；中位年龄，51.7 岁）仅接受了 CE MR 成像。在两个心室的基底三分之一处采集短轴饱和恢复梯度回波节段，并计算右至左心室 PTT、LV FWHM 和 LV TTP。统计分析包括 Kruskal-Wallis 检验、Wilcoxon 秩和检验、Spearman 相关系数、多元线性回归分析和 Lin 相关系数分析。
与对照组受试者（中位数，6.4 秒；25 至 75 百分位数，5.7 至 7.1 秒；中位数，5.2 秒；25 至 75 百分位数，4.1 至 6.1 秒；中位数，3.2 秒；25 至 75 百分位数，2.8 至 3.8 秒；P <.01 ）和硬皮病但无 PAH 患者（中位数，6.5 秒；25 至 75 百分位数，5.6 至 7.0 秒；中位数，5.0 秒；25 至 75 百分位数，4.0 至 7.3 秒；中位数，3.6 秒；25 至 75 百分位数，2.7 至 4.0 秒；P <.02 ）相比，PAH 患者的 PTT（中位数，8.2 秒；25 至 75 百分位数，6.9 至 9.9 秒）、LV FWHM（中位数，8.2 秒；25 至 75 百分位数，5.7 至 11.4 秒）和 LV TTP（中位数，4.8 秒；25 至 75 百分位数，3.9 至 6.5 秒）显著延长（P <.01 ）。PTT、LV FWHM 和 LV TTP 与肺血管阻力指数（P <.01）、右心室每搏量指数（P ≤.01）和肺动脉顺应性（P ≤.02）相关。多元线性回归模型中，PTT、FWHM 和 TTP 与平均肺动脉压和心指数相关。
CE MR 衍生的 PTT、LV FWHM 和 LV TTP 是 PAH 患者肺血流动力学和心功能的非侵入性复合标志物。它们对患者预后的预测价值值得进一步研究。
