Ruile Philipp, Blanke Philipp, Krauss Tobias, Dorfs Stephan, Jung Bernd, Jander Nikolaus, Leipsic Jonathon, Langer Mathias, Neumann Franz-Josef, Pache Gregor
Department of Cardiology & Angiology II, University Heart Center Freiburg-Bad Krozingen, Germany.
Center for Heart Valve Innovations, University of British Columbia, St Pauls Hospital, Vancouver, Canada.
Eur Heart J Cardiovasc Imaging. 2016 Apr;17(4):458-66. doi: 10.1093/ehjci/jev188. Epub 2015 Jul 27.
To evaluate the feasibility of a non-contrast three-dimensional (3D)-FLASH magnetic resonance angiography (MRA) protocol for pre-procedural aortic annulus assessment for transcatheter aortic valve replacement (TAVR) in comparison with cardiac dual-source computed tomography angiography (CTA).
In this prospective study, 69 of 104 consecutive patients (mean age 81.8 ± 5.4 years, 37.7% arrhythmic) with severe aortic stenosis who had undergone pre-TAVR cardiac CTA received a respiratory and ECG-triggered, non-contrast 3D-FLASH MRA at 3 T. Annular area measurements were obtained at mid-diastole for both modalities whereas maximum systolic area was assessed by CTA only. Systolic MRA dimensions were modelled, by adding the relative difference of systolic and diastolic CTA area dimensions as a corrective factor. Hypothetical prosthesis sizing was performed based on systolic CTA, diastolic, and modelled systolic MRA area measurements. MR image quality and degree of annular calcifications were evaluated using 4-point-grading scales. The mean acquisition time was 14 ± 4.2 min. The mean image quality was 3.1 ± 0.9 with only two examinations rated non-diagnostic. The mean degree of calcifications was equal. As assessed by Bland-Altman analysis, there was no relevant systematic difference between area measurements for modelled systolic MRA and systolic CTA [the mean difference -3.1 mm(2) (limits of agreement -44.4 mm(2); 38.2 mm(2))]. Agreement for hypothetical prosthesis sizing was found in 63 of 67 (94%) patients for systolic CTA and modelled systolic MRA.
The employed non-contrast 3D-FLASH MRA protocol allows for reliable assessment of aortic annulus dimensions and calcifications even in the presence of arrhythmias in an all-comers pre-TAVR population. Implementation of this technique appears legitimate in patients at an increased risk for contrast-induced nephropathy.
与心脏双源计算机断层血管造影（CTA）相比，评估非增强三维（3D）-快速低角度激发磁共振血管造影（MRA）方案用于经导管主动脉瓣置换术（TAVR）术前主动脉瓣环评估的可行性。
在这项前瞻性研究中，104例连续的重度主动脉瓣狭窄患者（平均年龄81.8±5.4岁，37.7%为心律失常患者）在接受TAVR术前进行了心脏CTA检查，其中69例在3T条件下接受了呼吸和心电图触发的非增强3D-快速低角度激发MRA检查。两种检查方式均在舒张中期测量瓣环面积，而仅通过CTA评估最大收缩期面积。通过将收缩期和舒张期CTA面积维度的相对差异作为校正因子，对收缩期MRA维度进行建模。基于收缩期CTA、舒张期以及建模后的收缩期MRA面积测量结果进行假体尺寸的假设性评估。使用4分制评分量表评估MR图像质量和瓣环钙化程度。平均采集时间为14±4.2分钟。平均图像质量为3.1±0.9，仅有两次检查被评为非诊断性。钙化程度平均相同。通过Bland-Altman分析评估，建模后的收缩期MRA与收缩期CTA的面积测量之间无相关系统差异[平均差异为-3.1平方毫米（一致性界限为-44.4平方毫米；38.2平方毫米）]。在67例患者中的63例（94%）中，收缩期CTA与建模后的收缩期MRA在假体尺寸假设性评估方面具有一致性。
所采用的非增强3D-快速低角度激发MRA方案即使在所有拟行TAVR的患者中存在心律失常的情况下，也能可靠地评估主动脉瓣环尺寸和钙化情况。对于发生对比剂肾病风险增加的患者，实施该技术似乎是合理的。
