Department of Radiology, Northwestern University, Chicago, Illinois, USA.
Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, USA.
J Magn Reson Imaging. 2023 Mar;57(3):727-737. doi: 10.1002/jmri.28343. Epub 2022 Jul 9.
Pulmonary hypertension (PH) contributes to restricted flow through the pulmonary circulation characterized by elevated mean pulmonary artery pressure acquired from invasive right heart catheterization (RHC). MRI may provide a noninvasive alternative for diagnosis and characterization of PH.
To characterize PH via quantification of regional pulmonary transit times (rPTT).
Retrospective.
A total of 43 patients (58% female); 24 controls (33% female). RHC-confirmed patients classified as World Health Organization (WHO) subgroups 1-4.
FIELD STRENGTH/SEQUENCE: A 1.5 T/time-resolved contrast-enhanced MR Angiography (CE-MRA).
CE-MRA data volumes were combined into a 4D matrix (3D resolution + time). Contrast agent arrival time was defined as the peak in the signal-intensity curve generated for each voxel. Average arrival times within a vessel region of interest (ROI) were normalized to the main pulmonary artery ROI (t ) for eight regions to define rPTT for all subjects. Subgroup analysis included grouping the four arterial and four venous regions. Intraclass correlation analysis completed for reproducibility.
Analysis of covariance with age as covariate. A priori Student's t-tests or Wilcoxon rank-sum test; α = 0.05. Results compared to controls unless noted. Significant without listing P value. ICC ran as two-way absolute agreement model with two observers.
PH patients demonstrated elevated rPTT in all vascular regions; average rPTT increase in arterial and venous branches was 0.85 ± 0.15 seconds (47.7%) and 1.0 ± 0.18 seconds (16.9%), respectively. Arterial rPTT was increased for all WHO subgroups; venous regions were elevated for subgroups 2 and 4 (group 1, P = 0.86; group 3, P = 0.32). No significant rPTT differences were found between subgroups (P = 0.094-0.94). Individual vessel ICC values ranged from 0.58 to 0.97.
Noninvasive assessment of PH using standard-of-care time-resolved CE-MRA can detect increased rPTT in PH patients of varying phenotypes compared to controls.
1 TECHNICAL EFFICACY: Stage 3.
肺动脉高压（PH）导致肺循环血流受限，其特征为平均肺动脉压升高，可通过有创右心导管检查（RHC）获得。MRI 可能为 PH 的诊断和特征提供一种非侵入性的替代方法。
通过量化区域性肺动脉通过时间（rPTT）来描述 PH。
回顾性。
共 43 名患者（58%为女性）；24 名对照者（33%为女性）。RHC 证实的患者分为世界卫生组织（WHO）亚组 1-4 级。
磁场强度/序列：1.5T 时间分辨对比增强磁共振血管造影术（CE-MRA）。
CE-MRA 数据卷组合成一个 4D 矩阵（3D 分辨率+时间）。对比剂到达时间定义为每个体素生成的信号强度曲线的峰值。对感兴趣的血管区域（ROI）内的平均到达时间进行归一化，以将主肺动脉 ROI（t）定义为所有受试者的 rPTT。亚组分析包括将四个动脉和四个静脉区域分组。使用两次观察者的双向绝对一致性模型进行组内相关分析以评估重复性。
协方差分析，以年龄为协变量。先验学生 t 检验或 Wilcoxon 秩和检验；α=0.05。除非另有说明，否则将结果与对照组进行比较。无显著差异但列出 P 值。ICC 作为双向绝对一致性模型，由两名观察者进行。
PH 患者所有血管区域的 rPTT 均升高；动脉和静脉分支的平均 rPTT 分别增加 0.85±0.15 秒（47.7%）和 1.0±0.18 秒（16.9%）。所有 WHO 亚组的动脉 rPTT 均升高；静脉区域在亚组 2 和 4 中升高（组 1，P=0.86；组 3，P=0.32）。亚组之间未发现 rPTT 差异有统计学意义（P=0.094-0.94）。各血管 ICC 值范围为 0.58 至 0.97。
使用标准护理时间分辨 CE-MRA 对 PH 患者进行非侵入性评估，与对照组相比，可检测出不同表型 PH 患者的 rPTT 增加。
1 技术功效：3 级。
