Richau Johanna, Dieringer Matthias A, Traber Julius, von Knobelsdorff-Brenkenhoff Florian, Greiser Andreas, Schwenke Carsten, Schulz-Menger Jeanette
Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, joint cooperation of the Max-Delbrück-Centrum and Charité -Medical University Berlin, Berlin, Germany.
Siemens Healthcare GmbH, Erlangen, Germany.
J Cardiovasc Magn Reson. 2017 Jan 16;19(1):5. doi: 10.1186/s12968-016-0319-1.
Cardiovascular Magnetic Resonance is often used to evaluate patients after heart valve replacement. This study systematically analyses the influence of heart valve prostheses on phase contrast measurements in a phantom trial.
Two biological and one mechanical aortic valve prostheses were integrated in a flow phantom. B maps and phase contrast measurements were acquired at a 1.5 T MR scanner using conventional gradient-echo sequences in predefined distances to the prostheses. Results were compared to measurements with a synthetic metal-free aortic valve.
The flow results at the level of the prosthesis differed significantly from the reference flow acquired before the level of the prosthesis. The maximum flow miscalculation was 154 ml/s for one of the biological prostheses and 140 ml/s for the mechanical prosthesis. Measurements with the synthetic aortic valve did not show significant deviations. Flow values measured approximately 20 mm distal to the level of the prosthesis agreed with the reference flow for all tested all prostheses.
The tested heart valve prostheses lead to a significant deviation of the measured flow rates compared to a reference. A distance of 20 mm was effective in our setting to avoid this influence.
心血管磁共振成像常用于评估心脏瓣膜置换术后的患者。本研究在体模试验中系统分析了心脏瓣膜假体对相位对比测量的影响。
将两个生物主动脉瓣假体和一个机械主动脉瓣假体集成到一个血流模拟体模中。在1.5 T磁共振扫描仪上，使用传统梯度回波序列在距假体预定距离处采集B图和相位对比测量数据。将结果与使用无金属合成主动脉瓣的测量结果进行比较。
假体水平处的血流结果与假体水平之前采集的参考血流结果有显著差异。其中一个生物假体的最大血流计算误差为154 ml/s，机械假体为140 ml/s。使用合成主动脉瓣进行的测量未显示出显著偏差。在距假体水平约20 mm处测量的血流值与所有测试假体的参考血流值一致。
与参考值相比，测试的心脏瓣膜假体导致测量流速出现显著偏差。在我们的实验环境中，20 mm的距离可有效避免这种影响。
