Yang Hsin-Jung, Sharif Behzad, Pang Jianing, Kali Avinash, Bi Xiaoming, Cokic Ivan, Li Debiao, Dharmakumar Rohan
Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
Department of Bioengineering, University of California, Los Angeles, California, USA.
Magn Reson Med. 2016 Jan;75(1):126-36. doi: 10.1002/mrm.25576. Epub 2015 Mar 6.
To develop and test a time-efficient, free-breathing, whole heart T2 mapping technique at 3.0T.
ECG-triggered three-dimensional (3D) images were acquired with different T2 preparations at 3.0T during free breathing. Respiratory motion was corrected with a navigator-guided motion correction framework at near perfect efficiency. Image intensities were fit to a monoexponential function to derive myocardial T2 maps. The proposed 3D, free breathing, motion-corrected (3D-FB-MoCo) approach was studied in ex vivo canine hearts and kidneys, healthy volunteers, and canine subjects with acute myocardial infarction (AMI).
Ex vivo T2 values from proposed 3D T2 -prep gradient echo were not different from two-dimensional (2D) spin echo (P = 0.7) and T2 -prep balanced steady-state free precession (bSSFP) (P = 0.7). In healthy volunteers, compared with 3D-FB-MoCo and breath-held 2D T2 -prep bSSFP (2D-BH), non-motion-corrected (3D-FB-Non-MoCo) myocardial T2 was longer, had a larger coefficient of variation (COV), and had a lower image quality (IQ) score (T2 = 40.3 ms, COV = 38%, and IQ = 2.3; all P < 0.05). Conversely, the mean and COV and IQ of 3D-FB-MoCo (T2 = 37.7 ms, COV = 17%, and IQ = 3.5) and 2D-BH (T2 = 38.0 ms, COV = 15%, and IQ = 3.8) were not different (P = 0.99, P = 0.74, and P = 0.14, respectively). In AMI, T2 values and edema volumes from 3D-FB-MoCo and 2D-BH were closely correlated (R(2) = 0.88 and 0.96, respectively).
The proposed whole heart T2 mapping approach can be performed within 5 min with similar accuracy to that of the 2D-BH T2 mapping approach.
开发并测试一种在3.0T场强下高效、自由呼吸的全心T2映射技术。
在3.0T场强下，于自由呼吸期间采用不同的T2准备方法采集心电图触发的三维（3D）图像。利用导航器引导的运动校正框架以近乎完美的效率校正呼吸运动。将图像强度拟合为单指数函数以得出心肌T2图谱。在离体犬心和肾脏、健康志愿者以及急性心肌梗死（AMI）犬类受试者中研究了所提出的三维、自由呼吸、运动校正（3D-FB-MoCo）方法。
所提出的3D T2准备梯度回波得出的离体T2值与二维（2D）自旋回波（P = 0.7）和T2准备平衡稳态自由进动（bSSFP）（P = 0.7）的结果无差异。在健康志愿者中，与3D-FB-MoCo和屏气二维T2准备bSSFP（2D-BH）相比，未进行运动校正的（3D-FB-Non-MoCo）心肌T2更长，变异系数（COV）更大，图像质量（IQ）评分更低（T2 = 40.3 ms，COV = 38%，IQ = 2.3；所有P < 0.05）。相反，3D-FB-MoCo（T2 = 37.7 ms，COV = 17%，IQ = 3.5）和2D-BH（T2 = 38.0 ms，COV = 15%，IQ = 3.8）的平均值、COV和IQ无差异（分别为P = 0.99、P = 0.74和P = 0.14）。在AMI中，3D-FB-MoCo和2D-BH得出的T2值与水肿体积密切相关（R²分别为0.88和0.96）。
所提出的全心T2映射方法可在5分钟内完成，其准确性与2D-BH T2映射方法相似。
