Rengier Fabian, Delles Michael, Eichhorn Joachim, Azad Yoo-Jin, von Tengg-Kobligk Hendrik, Ley-Zaporozhan Julia, Dillmann Rüdiger, Kauczor Hans-Ulrich, Unterhinninghofen Roland, Ley Sebastian
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany,
Int J Cardiovasc Imaging. 2015 Apr;31(4):823-30. doi: 10.1007/s10554-015-0604-3. Epub 2015 Feb 3.
To assess spatial and temporal pressure characteristics in patients with repaired aortic coarctation compared to young healthy volunteers using time-resolved velocity-encoded three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) and derived 4D pressure difference maps. After in vitro validation against invasive catheterization as gold standard, 4D flow MRI of the thoracic aorta was performed at 1.5T in 13 consecutive patients after aortic coarctation repair without recoarctation and 13 healthy volunteers. Using in-house developed processing software, 4D pressure difference maps were computed based on the Navier-Stokes equation. Pressure difference amplitudes, maximum slope of pressure amplitudes and spatial pressure range at mid systole were retrospectively measured by three readers, and twice by one reader to assess inter- and intraobserver agreement. In vitro, pressure differences derived from 4D flow MRI showed excellent agreement to invasive catheter measurements. In vivo, pressure difference amplitudes, maximum slope of pressure difference amplitudes and spatial pressure range at mid systole were significantly increased in patients compared to volunteers in the aortic arch, the proximal descending and the distal descending thoracic aorta (p < 0.05). Greatest differences occurred in the proximal descending aorta with values of the three parameters for patients versus volunteers being 19.7 ± 7.5 versus 10.0 ± 2.0 (p < 0.001), 10.9 ± 10.4 versus 1.9 ± 0.4 (p = 0.002), and 8.7 ± 6.3 versus 1.6 ± 0.9 (p < 0.001). Inter- and intraobserver agreements were excellent (p < 0.001). Noninvasive 4D pressure difference mapping derived from 4D flow MRI enables detection of altered intraluminal aortic pressures and showed significant spatial and temporal changes in patients with repaired aortic coarctation.
使用时间分辨速度编码三维相位对比磁共振成像（4D 流动 MRI）和衍生的 4D 压差图，评估与年轻健康志愿者相比，主动脉缩窄修复患者的空间和时间压力特征。在以侵入性导管插入术作为金标准进行体外验证后，对 13 例连续的主动脉缩窄修复后无再缩窄的患者和 13 名健康志愿者在 1.5T 下进行胸主动脉的 4D 流动 MRI 检查。使用自行开发的处理软件，基于纳维-斯托克斯方程计算 4D 压差图。由三名阅片者回顾性测量收缩中期的压差幅度、压力幅度的最大斜率和空间压力范围，一名阅片者测量两次以评估观察者间和观察者内的一致性。在体外，4D 流动 MRI 得出的压差与侵入性导管测量结果显示出极好的一致性。在体内，与志愿者相比，患者在主动脉弓、近端降主动脉和远端降主动脉的收缩中期压差幅度、压差幅度的最大斜率和空间压力范围显著增加（p < 0.05）。最大差异出现在近端降主动脉，患者与志愿者的三个参数值分别为 19.7 ± 7.5 与 10.0 ± 2.0（p < 0.001）、10.9 ± 10.4 与 1.9 ± 0.4（p = 0.002）以及 8.7 ± 6.3 与 1.6 ± 0.9（p < 0.001）。观察者间和观察者内的一致性极佳（p < 0.001）。源自 4D 流动 MRI 的无创 4D 压差映射能够检测主动脉腔内压力的改变，并显示出主动脉缩窄修复患者存在显著的空间和时间变化。
