Dong Zhenxiang, Guo Yihao, Liu Qiang, Zhang Yizhe, Qiu Qianyi, Zhang Xiaodong, Feng Yanqiu
School of Biomedical Engineering, Guangdong Provincial Orthopedic Research Institute, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China.
Guangdong Provincial Key Laboratory of Medical Imaging Processing, Southern Medical University, Guangzhou 510515, China, Guangdong Provincial Orthopedic Research Institute, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2025 Jun 20;45(6):1336-1342. doi: 10.12122/j.issn.1673-4254.2025.06.23.
To propose a single repetition time (TR) quantitative magnetic susceptibility imaging method for the lumbar spine using bipolar readout gradient, and compare the quantitative magnetic susceptibility measurement using single TR and dual TR methods for the lumbar spine with different bone densities.
A translation correction method was proposed to correct spatial misalignment along the frequency encoding direction between positive and negative gradient readout images, and the phase difference between the images was eliminated using a phase correction method. The data of lumbar vertebrae L1-L5 were collected using single TR and dual TR methods from 6 normal individuals, 2 patients with osteopenia, and 2 patients with osteoporosis. The magnetic susceptibility map was reconstructed, the quantitative results of single TR before and after correction were compared with those of the dual TR method.
The linear regression result of the lumbar spine magnetic susceptibility values obtained by the single TR method before calibration and the dual TR method is Y=0.64X-11.61. The linear regression result of the lumbar spine magnetic susceptibility values corrected by the single TR method and the dual TR method is =1.03+0.25. The results of the corrected single TR method were highly consistent with those of the dual TR method, and the calibrated single TR method could effectively distinguish osteopenia and osteoporosis patients from normal individuals.
The calibrated single TR bipolar readout gradient method can generate artifact-free lumbar spine quantitative magnetic susceptibility distribution maps and reduce data acquisition time by 50%.
提出一种使用双极读出梯度的腰椎单重复时间（TR）定量磁敏感成像方法，并比较使用单TR和双TR方法对不同骨密度腰椎进行定量磁敏感测量的结果。
提出一种平移校正方法来校正正负梯度读出图像之间沿频率编码方向的空间错位，并使用相位校正方法消除图像之间的相位差。采用单TR和双TR方法收集了6名正常个体、2名骨质减少患者和2名骨质疏松患者的L1-L5腰椎数据。重建磁敏感图，比较校正前后单TR方法与双TR方法的定量结果。
校准前单TR方法与双TR方法获得的腰椎磁敏感值的线性回归结果为Y=0.64X-11.61。单TR方法校正后与双TR方法的腰椎磁敏感值的线性回归结果为 =1.03+0.25。校正后的单TR方法结果与双TR方法高度一致，校准后的单TR方法能够有效区分骨质减少和骨质疏松患者与正常个体。
校准后的单TR双极读出梯度方法可生成无伪影的腰椎定量磁敏感分布图，并将数据采集时间减少50%。
