Field map-based rectification of susceptibility distortion and signal compensation in diffusion tensor imaging
- 医学院－已发表论文 
目的采用基于体素的场图对磁共振弥散张量成像(diffusion-tensor; imaging,DTI)进行几何变形矫正及信号补偿研究,扩大DTI临床研究及应用价值。材料与方法获取29名健康人脑场图,分别对其DTI进行相位反; 卷积计算及信号校准补偿,将结果配准到3D结构图像。选择对磁场敏感的双侧颅底额叶和颞叶作为观察脑区,对磁场不敏感的丘脑作为对照脑区,对部分各向异性; (fractional; anisotropy,FA)值及信号的差异及其与结构像的形态差异进行统计分析。结果在颅底额叶和颞叶,DTI的磁敏感变形得到了矫正,因场不均性导致; 的信号损失得到了补偿。结论高场中DTI的畸变及体素信号丢失可应用场图的校准得到明显矫正,有利于进一步扩大高场DTI在临床中的应用价值。Objective: This study was designed to employ the voxel-based field map; to rectify the geometric deformation and compensate the signal loss of; diffusion tensor imaging (DTI), and thus facilitate the studies and; clinical applications of DTI. Materials and Methods: Brain field maps; from 29 healthy persons were first used to get B1 field heterogeneous; signals, and then the compensation and phase disconsolation of signals; were performed. Finally, the geometry deformations of DTI were rectified; and registered to 3D images. Magnetic sensitive bilateral temporal lobes; and frontal lobes were selected as regions of interesting and meanwhile,; magnetic insensitive thalamus was selected as control area. Results:; Geometry deformations of DTI produced by different susceptibilities; between specific tissues were completely rectified, and thus the signal; loss was compensated and the accuracy of DTI was significantly enhanced.; Conclusion: Signal compensations and deformation rectifications can be; well achieved using field map, which may improve the applications of DTI; in neurosurgery.