Measurement of Myocardial T1ρ with a Motion Corrected, Parametric Mapping Sequence in Humans.
Measurement of Myocardial T1ρ with a Motion Corrected, Parametric Mapping Sequence in Humans.
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DOI：
10.1371/journal.pone.0151144
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Witschey WR
中科院分区：
文献类型：
--
作者：
Berisha S;Han J;Shahid M;Han Y;Witschey WR
开发一种稳健的T1ρ磁共振成像（MRI）序列，用于评估人类心肌疾病。我们开发了一种屏气T1ρ标测方法，使用单次激发、T1ρ准备的平衡稳态自由进动（bSSFP）序列。模拟磁化轨迹以识别T1ρ误差的来源。为了限制运动伪影，使用基于光流的图像配准方法来对准T1ρ图像。这些方法的重现性和准确性进行了评估，在phantomy和10名健康受试者。结果显示1例室前收缩（PVC）患者，1例慢性心肌梗死（MI）患者和2例肥厚型心肌病（HCM）患者。在体模中，60 bpm时的平均偏倚为1.0 ± 2.7 msec（100 msec体模）和0.9 ± 0.9 msec（60 msec体模），80 bpm时为2.2 ± 3.2 msec（100 msec）和1.4 ± 0.9 msec（60 msec）。60 bpm时的变异系数（COV）为2.2（100 msec）和1.3（60 msec），80 bpm时为2.6（100 msec）和1.4（60 msec）。运动校正改善了受试者中T1ρ图像的对齐，如通过Dice评分系数（DSC）从0.76增加到0.88所确定的。T1ρ重复性高（COV < 0.05，组内相关系数（ICC）= 0.85-0.97）。正常人心肌T1ρ值为63.5 ± 4.6 msec。在患者中，晚期钆增强（LGE）MRI与T1ρ弛豫时间增加之间具有良好的对应性。单次激发、运动校正、自旋回波、自旋锁定MRI允许在屏气时进行2D T1ρ标测，具有良好的准确度和精度。
To develop a robust T1ρ magnetic resonance imaging (MRI) sequence for assessment of myocardial disease in humans. We developed a breath-held T1ρ mapping method using a single-shot, T1ρ-prepared balanced steady-state free-precession (bSSFP) sequence. The magnetization trajectory was simulated to identify sources of T1ρ error. To limit motion artifacts, an optical flow-based image registration method was used to align T1ρ images. The reproducibility and accuracy of these methods was assessed in phantoms and 10 healthy subjects. Results are shown in 1 patient with pre-ventricular contractions (PVCs), 1 patient with chronic myocardial infarction (MI) and 2 patients with hypertrophic cardiomyopathy (HCM). In phantoms, the mean bias was 1.0 ± 2.7 msec (100 msec phantom) and 0.9 ± 0.9 msec (60 msec phantom) at 60 bpm and 2.2 ± 3.2 msec (100 msec) and 1.4 ± 0.9 msec (60 msec) at 80 bpm. The coefficient of variation (COV) was 2.2 (100 msec) and 1.3 (60 msec) at 60 bpm and 2.6 (100 msec) and 1.4 (60 msec) at 80 bpm. Motion correction improved the alignment of T1ρ images in subjects, as determined by the increase in Dice Score Coefficient (DSC) from 0.76 to 0.88. T1ρ reproducibility was high (COV < 0.05, intra-class correlation coefficient (ICC) = 0.85–0.97). Mean myocardial T1ρ value in healthy subjects was 63.5 ± 4.6 msec. There was good correspondence between late-gadolinium enhanced (LGE) MRI and increased T1ρ relaxation times in patients. Single-shot, motion corrected, spin echo, spin lock MRI permits 2D T1ρ mapping in a breath-hold with good accuracy and precision.