MultiBand SENSE를 사용한 Corticospinal tract Diffusion Tensor Imaging의 유용성 평가

다국어 초록 (Multilingual Abstract)

Purpose：In this study to evaluate the clinical usefulness of diffusion tensor imaging(DTI) using Multiband(MB) SENSE, which is a technique for simultaneous excitation and acquisition of multiple slices, in the corticospinal tract.
Object and method：We obtained images in two ways: conventional-DTI and MB SENSE DTI (MB factor : 2, 3) in 7 healthy adult volunteers (male: 6, female: 1, mean age: 33).The ROI was set in the pyramidal tract of the pons and the posterior limb of the internal capsule, and the tracking of the corticospinal tract through the two ROIs was performed. For quantitative analysis, fractional anisotropy (FA), apparent diffusivity coefficient (ADC), length of the tracked fiber, and number of white matter fibers were measured by two radiology technologists. For qualitative analysis, The accuracy of the pyramidal tract, the posterior limb of the internal capsule and the tracked white matter fibers were evaluated by 5 person who work at MRI over 5 years that were classified as grade 4 ;poor (1), fair (2), good (3), excellent (4)
Result：The FA of the pyramidal tract of the pons was 0.508 ± 0.165 for conventional DTI, 0.486 ± 0.140 for MBf2, and 0.433 ± 0.150 for MBf3. The ADC values were measured as 0.783 ± 0.194, 0.825 ± 0.197 and 1.022 ± 0.228 in conventional DTI, MBf2 and MBf3, respectively. The FA of internal capsule was 0.521 ± 0.185for conventional DTI, 0.538 ± 0.175 for MBf2, and and 0.506 ± 0.161 for MBf3. ADC values were measured as 0.719 ± 0.119, 0.730 ± 0.105 and 0.865 ± 0.172 respectively in conventional DTI, MBf2 and MBf3. There was no significant difference between conventional DTI and MBf2 in FA and ADC. The mean lengths (mm) of the white matter fibers measured in the corticospinal tract were 124.486 ± 18.523, 115.493 ± 19.568, and 100.224 ± 18.368 for conventional DTI, MBf2 and MBf3. The number of tracked white matter fibers was 1294.3, 1090.6, 123.3. for conventional DTI, MBf2 and MBf3. As MBf increased, the length and number of white fibers decreased. In MBf3, the number of white fibers decreased sharply. In the qualitative evaluation, the accuracy of the pyramidal tract was 3.86 ± 0.14, 3.83 ± 0.06 and 2.71 ± 0.49 for conventional DTI, MBf2 and MBf3. MBf2 was similar to conventional image, but MBf3 was remarkably low. The accuracy of the internal capsule was 3.94 ± 0.09, 3.91 ± 0.09and 3.4 ± 0.01for conventional DTI, MBf2 and MBf3.The number of tracked white matter fibers was 3.94±0.09, 3.91±0.1 and 2.54±0.26. for conventional DTI, MBf2 and MBf3. When the number of white matter fibers was visually observed, there was no significant difference between conventional and MBf2 images.
Conclusion：MB SENSE is a method that enables simultaneous excitation and acquisition of multiple volumes in a sing shot EPI sequence. The main advantage of the diffusion image using MB SENSE is that the acquisition time of the image is reduced by about 40% when MBf2 is used. Quantitative and qualitative evaluation of images showed little difference between conventional and MBf2 DTI. Therefore, diffusion tensor imaging using MBf2 may be helpful for patients with severe motion or discomfort during long examination time.