Validation and reproducibility of cardiovascular 4D-flow MRI from two vendors using 2 × 2 parallel imaging acceleration in pulsatile flow phantom and in vivo with and without respiratory gating
Validation and reproducibility of cardiovascular 4D-flow MRI from two vendors using 2 × 2 parallel imaging acceleration in pulsatile flow phantom and in vivo with and without respiratory gating
复制标题
两家供应商的心血管 4D 流 MRI 的验证和可重复性，在脉动流体模和体内（有或没有呼吸门控）中使用 2 × 2 并行成像加速
作者：
J. Bock;J. Töger;S. Bidhult;K. Markenroth Bloch;P. Arvidsson;Mikael Kanski;H. Arheden;F. Testud;A. Greiser;E. Heiberg;M. Carlsson
背景4D-Flow磁共振成像(MRI)的应用越来越广泛。目的验证体模和活体的4D血流序列，比较有无呼吸门控时的体积流量和动能(KE)。材料与方法使用飞利浦医疗集团的Achieva dStream和西门子医疗集团的Magnetom Aera 1.5-T扫描仪。Phantom Verify以4D-Flow MRI和激光粒子成像测速仪(PIV)为参照标准，测量脉动型三维血流。10名健康受试者接受了3次心脏磁共振检查，包括电影成像、2D-Flow(主动脉、肺动脉)和2 × 2加速4D-Flow有(Resp+)呼吸门控(Resp+)和无(Resp−)呼吸门。在两台扫描仪上连续进行检查，一次检查在两周内重复进行。比较二维流和四维流在大血管内的体积流量。计算左心室各时相和体素的KE。结果体模结果显示两种扫描仪均具有较高的准确度和精密度。在体内，Resp+的Aera原型的体积流量的准确性和精密度(P <； 0.001)高于Achieva的产品序列(-17.8 ± 18.6 mL，r = 0.56)。4D-Flow-Resp−对AERA的偏倚(-9.3 ± 9.6 mL，r = 0.90)略大于Resp+(P = 0.005)。KE测量显示，同一天的扫描仪之间的差异比同一扫描仪在不同日期的差异更大。结论在临床应用之前，需要对4D-FLOW进行体内序列特异性验证。4D-FLOW与AERA原型序列和临床可接受的采集时间(<；10分钟)显示在健康对照中可接受的偏倚，可考虑用于临床。个体内的KE比较应该使用相同的序列。
Background 4D-flow magnetic resonance imaging (MRI) is increasingly used. Purpose To validate 4D-flow sequences in phantom and in vivo, comparing volume flow and kinetic energy (KE) head-to-head, with and without respiratory gating. Material and Methods Achieva dStream (Philips Healthcare) and MAGNETOM Aera (Siemens Healthcare) 1.5-T scanners were used. Phantom validation measured pulsatile, three-dimensional flow with 4D-flow MRI and laser particle imaging velocimetry (PIV) as reference standard. Ten healthy participants underwent three cardiac MRI examinations each, consisting of cine-imaging, 2D-flow (aorta, pulmonary artery), and 2 × 2 accelerated 4D-flow with (Resp+) and without (Resp−) respiratory gating. Examinations were acquired consecutively on both scanners and one examination repeated within two weeks. Volume flow in the great vessels was compared between 2D- and 4D-flow. KE were calculated for all time phases and voxels in the left ventricle. Results Phantom results showed high accuracy and precision for both scanners. In vivo, higher accuracy and precision (P < 0.001) was found for volume flow for the Aera prototype with Resp+ (–3.7 ± 10.4 mL, r = 0.89) compared to the Achieva product sequence (–17.8 ± 18.6 mL, r = 0.56). 4D-flow Resp− on Aera had somewhat larger bias (–9.3 ± 9.6 mL, r = 0.90) compared to Resp+ (P = 0.005). KE measurements showed larger differences between scanners on the same day compared to the same scanner at different days. Conclusion Sequence-specific in vivo validation of 4D-flow is needed before clinical use. 4D-flow with the Aera prototype sequence with a clinically acceptable acquisition time (<10 min) showed acceptable bias in healthy controls to be considered for clinical use. Intra-individual KE comparisons should use the same sequence.