Wintersperger Bernd J, Bauner Kerstin, Reeder Scott B, Friedrich Denise, Dietrich Olaf, Sprung Katrin C, Picciolo Michele, Nikolaou Konstantin, Reiser Maximilian F, Schoenberg Stefan O
Department of Clinical Radiology, University Hospitals, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
Invest Radiol. 2006 Feb;41(2):141-7. doi: 10.1097/01.rli.0000192419.08733.37.
We sought to evaluate the impact of 3.0 T on accelerated CINE steady-state free precession (SSFP) regarding signal parameters and its volumetric accuracy.
Ten individuals underwent cardiac CINE imaging at 1.5 T and 3.0 T using standard single-slice CINE and multislice TSENSE-accelerated CINE (5 slices/breath-hold) with 4-fold acceleration. Data were evaluated for left ventricular volumetric parameters (EDV, ESV, and EF) as well as for SNR and CNR. Phantom based data allowed for g-factor evaluation for estimation of noise levels for accelerated data sets. Volumetric results and signal parameters were compared with results of single-slice CINE SSFP at 1.5 T as standard of reference (SOR).
Single-slice CINE at 3.0 T showed a approximately 90% increase in CNR compared with the SOR (P < 0.001). At 3.0 T, TSENSE CINE showed a less pronounced estimated loss in CNR (-58 +/- 6%) compared with single-slice CINE than at 1.5 T (-71 +/- 2%). 3.0 T TSENSE CINE showed a 21 +/- 18% lower CNR than the nonaccelerated 1.5 T CINE (P < 0.05). EF results for all data sets did not show any significant error while for EDV some errors have been encountered.
3.0 T permits compensation for the high CNR loss, which accompanies the 4-fold TSENSE acceleration at 1.5 T and shows volumetric accuracy. The use of parallel imaging may help to alleviate SAR limitations at higher field strength.
我们试图评估3.0 T对加速电影稳态自由进动(SSFP)在信号参数及其容积准确性方面的影响。
10名受试者分别在1.5 T和3.0 T下接受心脏电影成像,使用标准单层面电影成像和多层TSENSE加速电影成像(每屏气采集5层),加速倍数为4倍。对左心室容积参数(舒张末期容积、收缩末期容积和射血分数)以及信噪比和对比噪声比进行评估。基于体模的数据可用于评估g因子,以估计加速数据集的噪声水平。将容积结果和信号参数与1.5 T单层面电影SSFP的结果进行比较,作为参考标准(SOR)。
与参考标准相比,3.0 T的单层面电影成像的对比噪声比增加了约90%(P < 0.001)。在3.0 T时,与单层面电影成像相比,TSENSE电影成像的对比噪声比估计损失较小(-58±6%),低于1.5 T时的情况(-71±2%)。3.0 T的TSENSE电影成像的对比噪声比比未加速的1.5 T电影成像低21±18%(P < 0.05)。所有数据集的射血分数结果均未显示任何显著误差,而舒张末期容积则出现了一些误差。
3.0 T能够补偿1.5 T时4倍TSENSE加速所伴随的高对比噪声比损失,并显示出容积准确性。使用并行成像可能有助于缓解高场强下的比吸收率限制。