Shiina Yumi, Inai Kei, Takahashi Tatsunori, Shimomiya Yamato, Ishizaki Umiko, Fukushima Kenji, Nagao Michinobu
Department of Clinical Research for ACHD, Tokyo Women's Medical University, 8-1 Wakamatsu Kawada, Tokyo, 1628666, Japan.
Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
Pediatr Cardiol. 2018 Feb;39(2):375-383. doi: 10.1007/s00246-017-1765-8. Epub 2017 Nov 2.
We developed a novel imaging technique, designated as vortex flow (VF) mapping, which presents a vortex flow visually on conventional two-dimensional (2D) cine MRI. Using it, we assessed circumferential VF patterns and influences on RA thrombus and supraventricular tachycardia (SVT) in AP connection-type Fontan circulation. Retrospectively, we enrolled 27 consecutive patients (25.1 ± 9.2 years) and 7 age-matched controls who underwent cardiac MRI. Conventional cine images acquired using a 1.5-Tesla scanner were scanned for axial and coronal cross section of the RA. We developed "vortex flow mapping" to demonstrate the ratio of the circumferential voxel movement at each phase to the total movement throughout a cardiac cycle towards the RA center. The maximum ratio was used as a magnitude of vortex flow (MVF%) in RA cine imaging. We also measured percentages of strong and weak VF areas (VFA%). Furthermore, in 10 out of 27, we compared VF between previous CMR (3.8 ± 1.5 years ago) and latest CMR. Of the patients, 15 had cardiovascular complications (Group A); 12 did not (Group B). A transaxial image showed that strong VFA% in Group A was significantly smaller than that in Group B or controls. A coronal view revealed that strong VFA% was also smaller, and weak VFA% was larger in Group A than in Group B or controls (P < 0.05, and P < 0.05). Maximum MVF% in Group A was significantly smaller than in other groups (P < 0.001). Univariate logistic analyses revealed weak VFA% on a coronal image, and serum total bilirubin level as factors affecting cardiovascular complications (Odds ratio 1.14 and 66.1, 95% CI 1.004-1.30 and 1.59-2755.6, P values < 0.05 and < 0.05, respectively). Compared to the previous CMR, smaller maximum VMF%, smaller strong VFA%, and larger weak VFA% were identified in the latest CMR. Circumferentially weak VFA% on a coronal image can be one surrogate marker of SVT and thrombus in AP connection-type Fontan circulation. This simple VF assessment is clinically useful to detect blood stagnation.
我们开发了一种新型成像技术，称为涡流（VF）映射，它能在传统二维（2D）电影磁共振成像（cine MRI）上直观地呈现涡流。利用该技术，我们评估了心房连接型Fontan循环中圆周VF模式及其对右心房（RA）血栓和室上性心动过速（SVT）的影响。我们回顾性纳入了27例连续患者（年龄25.1±9.2岁）和7名年龄匹配的对照者，他们均接受了心脏磁共振成像检查。使用1.5特斯拉扫描仪采集的传统电影图像用于扫描RA的轴向和冠状切面。我们开发了“涡流映射”来显示每个阶段圆周体素运动与整个心动周期朝向RA中心的总运动的比值。最大比值用作RA电影成像中涡流强度（MVF%）的大小。我们还测量了强VF区域和弱VF区域的百分比（VFA%）。此外，在27例患者中的10例中，我们比较了之前的心脏磁共振成像（3.8±1.5年前）和最新的心脏磁共振成像中的VF。这些患者中，15例有心血管并发症（A组）；12例没有（B组）。一幅横轴位图像显示，A组的强VFA%显著小于B组或对照组。一幅冠状位图像显示，A组的强VFA%也较小，而弱VFA%大于B组或对照组（P<0.05，P<0.05）。A组的最大MVF%显著小于其他组（P<0.001）。单因素逻辑分析显示，冠状位图像上的弱VFA%以及血清总胆红素水平是影响心血管并发症的因素（比值比分别为1.14和66.1，95%置信区间为1.004 - 1.30和1.59 - 2755.6，P值分别<0.05和<0.05）。与之前的心脏磁共振成像相比，最新的心脏磁共振成像显示最大VMF%更小、强VFA%更小以及弱VFA%更大。冠状位图像上圆周方向的弱VFA%可能是心房连接型Fontan循环中SVT和血栓的一个替代标志物。这种简单的VF评估在临床上对于检测血液淤滞很有用。
