Beerbaum Philipp, Körperich Hermann, Gieseke Jürgen, Barth Peter, Peuster Matthias, Meyer Hans
Klinik für Angeborene Herzfehler, Herz- und Diabeteszentrum, Nordrhein-Westfalen, Ruhr-Universität Bochum, Germany.
Circulation. 2003 Sep 16;108(11):1355-61. doi: 10.1161/01.CIR.0000087603.97036.C2. Epub 2003 Aug 25.
Parallel imaging by sensitivity encoding (SENSE) may considerably reduce scan time in MRI. For rapid flow quantification in children with congenital heart disease, we evaluated phase-contrast MRI (PC-MRI) techniques combined with SENSE.
In 22 pediatric patients (mean age, 7.2+/-6.2 years) with cardiac left-to-right shunt, blood flow rate in the pulmonary artery (Qp) and ascending aorta (Qs) and flow ratio Qp/Qs were determined by PC-MRI with SENSE reduction-factor 2 and 3 (SF-2 and SF-3). Additionally, we used PC-MRI with higher spatial in-plane resolution (1.6x2.1 versus 2.3x3.1 mm) with and without SF-3. Results were compared with a recently validated standard PC-MRI protocol and tested in vitro using a pulsatile flow phantom. Reduction of signal averages from 2 to 1 and application of SENSE accelerated flow measurements by a factor of 3.5 (5.2) using PC-MRI with SF-2 (SF-3) compared with standard PC-MRI. For blood flow rate through the pulmonary artery and aorta, as well as for the Qp/Qs ratio we found negligible differences of +/-3%, lower limits of agreement (mean+/-2 SD) of -7% to -18%, and upper limits of agreement (mean+/-2 SD) of +3 to +24%, demonstrating good agreement with standard PC-MRI. Mean Qp/Qs ratio by standard PC-MRI was 1.69+/-0.45 (range, 1.27 to 2.79). Interobserver variability was low, and high accuracy was confirmed in vitro for all protocols.
PC-MRI for flow quantitation may be combined with SENSE to achieve a substantive reduction of scanning time. In children with left-to-right shunt, Qp/Qs quantification is possible by PC-MRI+SF-3 in <60 seconds. Use of higher in-plane resolution did not improve measurement results.
灵敏度编码并行成像（SENSE）可显著缩短MRI扫描时间。为了对先天性心脏病患儿进行快速血流定量分析，我们评估了结合SENSE的相位对比MRI（PC-MRI）技术。
对22例患有心脏左向右分流的儿科患者（平均年龄7.2±6.2岁），采用SENSE缩减因子为2和3（SF-2和SF-3）的PC-MRI测定肺动脉（Qp）和升主动脉（Qs）的血流速度以及血流比Qp/Qs。此外，我们使用了具有更高面内空间分辨率（1.6×2.1对比2.3×3.1mm）的PC-MRI，分别采用和不采用SF-3。将结果与最近验证的标准PC-MRI方案进行比较，并在体外使用脉动血流模型进行测试。与标准PC-MRI相比，使用PC-MRI结合SF-2（SF-3）时，信号平均次数从2次减少到1次以及应用SENSE可使血流测量速度加快3.5（5.2）倍。对于通过肺动脉和主动脉的血流速度以及Qp/Qs比值，我们发现差异可忽略不计，为±3%，一致性下限（均值±2标准差）为-7%至-18%，一致性上限（均值±2标准差）为+3%至+24%，表明与标准PC-MRI具有良好的一致性。标准PC-MRI测得的平均Qp/Qs比值为1.69±0.45（范围为1.27至2.79）。观察者间的变异性较低，并且所有方案在体外均证实具有高准确性。
用于血流定量分析的PC-MRI可与SENSE相结合，以大幅缩短扫描时间。对于左向右分流的儿童，采用PC-MRI+SF-3可在60秒内完成Qp/Qs定量分析。使用更高的面内分辨率并未改善测量结果。
