Departments of Radiology, University of Wisconsin-Madison, School of Medicine and Public Health, 600 Highland Avenue, Madison, WI 53562, USA.
J Cardiovasc Magn Reson. 2012 Feb 7;14(1):16. doi: 10.1186/1532-429X-14-16.
To assess changes in right heart flow and pulmonary artery hemodynamics in patients with repaired Tetralogy of Fallot (rTOF) we used whole heart, four dimensional (4D) velocity mapping (VM) cardiovascular magnetic resonance (CMR).
CMR studies were performed in 11 subjects with rTOF (5M/6F; 20.1 ± 12.4 years) and 10 normal volunteers (6M/4F; 34.2 ± 13.4 years) on clinical 1.5T and 3.0T MR scanners. 4D VM-CMR was performed using PC VIPR (Phase Contrast Vastly undersampled Isotropic Projection Reconstruction). Interactive streamline and particle trace visualizations of the superior and inferior vena cava (IVC and SVC, respectively), right atrium (RA), right ventricle (RV), and pulmonary artery (PA) were generated and reviewed by three experienced readers. Main PA net flow, retrograde flow, peak flow, time-to-peak flow, peak acceleration, resistance index and mean wall shear stress were quantified. Differences in flow patterns between the two groups were tested using Fisher's exact test. Differences in quantitative parameters were analyzed with the Kruskal-Wallis rank sum test.
4D VM-CMR was successfully performed in all volunteers and subjects with TOF. Right heart flow patterns in rTOF subjects were characterized by (a) greater SVC/IVC flow during diastole than systole, (b) increased vortical flow patterns in the RA and in the RV during diastole, and (c) increased helical or vortical flow features in the PA's. Differences in main PA retrograde flow, resistance index, peak flow, time-to-peak flow, peak acceleration and mean wall shear stress were statistically significant.
Whole heart 4D VM-CMR with PC VIPR enables detection of both normal and abnormal right heart flow patterns, which may allow for comprehensive studies to evaluate interdependencies of post-surgically altered geometries and hemodynamics.
为了评估修复法洛四联症（rTOF）患者右心血流和肺动脉血流动力学的变化，我们使用了全心、四维（4D）速度图（VM）心血管磁共振（CMR）。
在临床 1.5T 和 3.0T 磁共振扫描仪上，对 11 例 rTOF 患者（5 男/6 女；20.1 ± 12.4 岁）和 10 例正常志愿者（6 男/4 女；34.2 ± 13.4 岁）进行了 CMR 研究。使用 PC VIPR（相位对比大欠采样各向同性投影重建）进行 4D VM-CMR。生成并由三位有经验的读者审查了上腔静脉（IVC 和 SVC）、右心房（RA）、右心室（RV）和肺动脉（PA）的 superior and inferior vena cava（分别为 IVC 和 SVC）、右心房（RA）、右心室（RV）和肺动脉（PA）的交互式流线和粒子轨迹可视化。定量测量主肺动脉净流量、反流流量、峰值流量、达峰时间、峰值加速度、阻力指数和平均壁面切应力。使用 Fisher 精确检验测试两组之间的流量模式差异。使用 Kruskal-Wallis 秩和检验分析定量参数差异。
所有志愿者和 TOF 患者均成功进行了 4D VM-CMR。rTOF 患者的右心血流模式表现为：（a）舒张期 SVC/IVC 流量大于收缩期，（b）舒张期 RA 和 RV 涡流模式增加，（c）PA 中螺旋或涡流模式增加。主肺动脉反流流量、阻力指数、峰值流量、达峰时间、峰值加速度和平均壁面切应力差异具有统计学意义。
使用 PC VIPR 的全心 4D VM-CMR 能够检测到正常和异常的右心血流模式，这可能允许进行全面的研究，以评估术后改变的几何形状和血流动力学之间的相互依赖关系。
