Frydrychowicz Alex, Arnold Raoul, Hirtler Daniel, Schlensak Christian, Stalder Aurelien F, Hennig Jürgen, Langer Mathias, Markl Michael
Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Germany.
J Cardiovasc Magn Reson. 2008 Jun 8;10(1):30. doi: 10.1186/1532-429X-10-30.
Aneurysm formation is a life-threatening complication after operative therapy in coarctation. The identification of patients at risk for the development of such secondary pathologies is of high interest and requires a detailed understanding of the link between vascular malformation and altered hemodynamics. The routine morphometric follow-up by magnetic resonance angiography is a well-established technique. However, the intrinsic sensitivity of magnetic resonance (MR) towards motion offers the possibility to additionally investigate hemodynamic consequences of morphological changes of the aorta. We demonstrate two cases of aneurysm formation 13 and 35 years after coarctation surgery based on a Waldhausen repair with a subclavian patch and a Vosschulte repair with a Dacron patch, respectively. Comprehensive flow visualization by cardiovascular MR (CMR) was performed using a flow-sensitive, 3-dimensional, and 3-directional time-resolved gradient echo sequence at 3T. Subsequent analysis included the calculation of a phase contrast MR angiography and color-coded streamline and particle trace 3D visualization. Additional quantitative evaluation provided regional physiological information on blood flow and derived vessel wall parameters such as wall shear stress and oscillatory shear index. The results highlight the individual 3D blood-flow patterns associated with the different vascular pathologies following repair of aortic coarctation. In addition to known factors predisposing for aneurysm formation after surgical repair of coarctation these findings indicate the importance of flow sensitive CMR to follow up hemodynamic changes with respect to the development of vascular disease.
动脉瘤形成是缩窄手术治疗后一种危及生命的并发症。识别有发生这种继发性病变风险的患者备受关注，这需要详细了解血管畸形与血流动力学改变之间的联系。通过磁共振血管造影进行常规形态学随访是一种成熟的技术。然而，磁共振（MR）对运动的固有敏感性提供了额外研究主动脉形态变化血流动力学后果的可能性。我们分别展示了两例在缩窄手术后13年和35年形成动脉瘤的病例，一例基于采用锁骨下补片的Waldhausen修复术，另一例基于采用涤纶补片的Vosschulte修复术。在3T条件下，使用血流敏感的三维三方向时间分辨梯度回波序列对心血管磁共振（CMR）进行全面的血流可视化。后续分析包括计算相位对比磁共振血管造影以及对彩色编码流线和粒子迹线进行三维可视化。额外的定量评估提供了关于血流的局部生理信息以及诸如壁面切应力和振荡切变指数等派生的血管壁参数。结果突出了与主动脉缩窄修复术后不同血管病变相关的个体三维血流模式。除了已知的缩窄手术修复后动脉瘤形成的易感因素外，这些发现表明血流敏感的CMR对于跟踪血管疾病发展过程中的血流动力学变化具有重要意义。
