Rengier Fabian, Wörz Stefan, Melzig Claudius, Ley Sebastian, Fink Christian, Benjamin Nicola, Partovi Sasan, von Tengg-Kobligk Hendrik, Rohr Karl, Kauczor Hans-Ulrich, Grünig Ekkehard
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany.
Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany.
PLoS One. 2016 Sep 14;11(9):e0162516. doi: 10.1371/journal.pone.0162516. eCollection 2016.
To demonstrate feasibility of automated 3D volumetry of central pulmonary arteries based on magnetic resonance angiography (MRA), to assess pulmonary artery volumes in patients with pulmonary hypertension compared to healthy controls, and to investigate the potential of the technique for predicting pulmonary hypertension.
MRA of pulmonary arteries was acquired at 1.5T in 20 patients with pulmonary arterial hypertension and 21 healthy normotensive controls. 3D model-based image analysis software was used for automated segmentation of main, right and left pulmonary arteries (MPA, RPA and LPA). Volumes indexed to vessel length and mean, minimum and maximum diameters along the entire vessel course were assessed and corrected for body surface area (BSA). For comparison, diameters were also manually measured on axial reconstructions and double oblique multiplanar reformations. Analyses were performed by two cardiovascular radiologists, and by one radiologist again after 6 months.
Mean volumes of MPA, RPA and LPA for patients/controls were 5508 ± 1236/3438 ± 749, 3522 ± 934/1664 ± 468 and 3093 ± 692/1812 ± 474 μl/(cm length x m2 BSA) (all p<0.001). Mean, minimum and maximum diameters along the entire vessel course were also significantly increased in patients compared to controls (all p<0.001). Intra- and interobserver agreement were excellent for both volume and diameter measurements using 3D segmentation (intraclass correlation coefficients 0.971-0.999, p<0.001). Area under the curve for predicting pulmonary hypertension using volume was 0.998 (95% confidence interval 0.990-1.0, p<0.001), compared to 0.967 using manually measured MPA diameter (95% confidence interval 0.910-1.0, p<0.001).
Automated MRA-based 3D volumetry of central pulmonary arteries is feasible and demonstrated significantly increased volumes and diameters in patients with pulmonary arterial hypertension compared to healthy controls. Pulmonary artery volume may serve as a superior predictor for pulmonary hypertension compared to manual measurements on axial images but verification in a larger study population is warranted.
基于磁共振血管造影（MRA）证明中央肺动脉自动三维容积测量的可行性，评估肺动脉高压患者与健康对照者的肺动脉容积，并研究该技术预测肺动脉高压的潜力。
在1.5T条件下对20例肺动脉高压患者和21例血压正常的健康对照者进行肺动脉MRA检查。使用基于三维模型的图像分析软件对主肺动脉、右肺动脉和左肺动脉（MPA、RPA和LPA）进行自动分割。评估以血管长度和沿整个血管行程的平均、最小和最大直径为指标的容积，并根据体表面积（BSA）进行校正。为作比较，还在轴向重建图像和双斜多平面重组图像上手动测量直径。由两名心血管放射科医生进行分析，一名放射科医生在6个月后再次进行分析。
患者/对照者的MPA、RPA和LPA平均容积分别为5508±1236/3438±749、3522±934/1664±468和3093±692/1812±474μl/（厘米长度×平方米BSA）（所有p<0.001）。与对照者相比，患者沿整个血管行程的平均、最小和最大直径也显著增加（所有p<0.001）。使用三维分割法进行容积和直径测量时，观察者内和观察者间的一致性都非常好（组内相关系数0.971 - 0.999，p<0.001）。使用容积预测肺动脉高压的曲线下面积为0.998（95%置信区间0.990 - 1.0，p<0.001），而使用手动测量的MPA直径时为0.967（95%置信区间0.910 - 1.0，p<0.001）。
基于MRA的中央肺动脉自动三维容积测量是可行的，与健康对照者相比，肺动脉高压患者的容积和直径显著增加。与在轴向图像上的手动测量相比，肺动脉容积可能是肺动脉高压更好的预测指标，但需要在更大的研究人群中进行验证。
