Santini Francesco, Kawel-Boehm N, Greiser A, Bremerich J, Bieri O
Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland.
Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland.
Magn Reson Med. 2015 Aug;74(2):365-71. doi: 10.1002/mrm.25402. Epub 2014 Aug 11.
To develop a novel sequence for simultaneous quantification of T1 and T2 relaxation times in the myocardium based on the transient phase of the balanced steady-state free precession.
A new prototype sequence, named "cardiac balanced-SSFP inversion recovery with interleaved sampling acquisition" (CABIRIA) was developed based on a single-shot bSSFP readout following an inversion pulse. With this method, T1 and T2 values can be calculated from the analysis of signal evolution. The scan duration for a single slice in vivo was 8 heartbeats, thus feasible in a breath-hold. The sequence was validated both in vitro by comparing it to conventional inversion recovery and multi-echo spin-echo methods and in 5 healthy volunteers by comparing it to the Modified Look-Locker Inversion Recovery (MOLLI) sequence and to a T2 quantification sequence based on multi-T2 -prepared bSSFP.
The method showed good agreement with conventional methods for both T1 and T2 measurements (concordance correlation coefficient ≥ 0.99) in vitro. In healthy volunteers the measured T1 values were 1227 ± 68 ms and T2 values 37.9 ± 2.4 ms, with similar inter- and intrasubject variability with respect to existing methods.
The proposed CABIRIA method enables simultaneous quantification of myocardial T1 and T2 values with good accuracy and precision.
基于平衡稳态自由进动的瞬态阶段,开发一种用于同时定量心肌T1和T2弛豫时间的新序列。
基于反转脉冲后的单次激发bSSFP读出,开发了一种名为“心脏平衡SSFP反转恢复与交错采样采集”(CABIRIA)的新原型序列。通过这种方法,可以从信号演变分析中计算出T1和T2值。体内单个切片的扫描持续时间为8个心跳周期,因此可以在屏气状态下完成。该序列在体外通过与传统反转恢复和多回波自旋回波方法进行比较进行验证,并在5名健康志愿者中通过与改良的Look-Locker反转恢复(MOLLI)序列以及基于多T2准备的bSSFP的T2定量序列进行比较进行验证。
该方法在体外对T1和T2测量均与传统方法显示出良好的一致性(一致性相关系数≥0.99)。在健康志愿者中,测得的T1值为1227±68毫秒,T2值为37.9±2.4毫秒,与现有方法相比,受试者间和受试者内的变异性相似。
所提出的CABIRIA方法能够以良好的准确性和精密度同时定量心肌T1和T2值。