颈髓扩散张量磁共振成像扫描参数的比较

目的 探索颈髓扩散张量磁共振成像(DTI)最佳扫描参数. 资料与方法 对40名成年健康志愿者行颈髓DTI,比较不同b值、扩散敏感梯度方向数、激励次数(NEX)、层厚对图像质量的影响.第1组,b值分别取400 mm2/s、700 mm2/s、1000 mm2/s;第2组,扩散敏感梯度方向数分别取6个、13个、25个;第3组,激励次数分别取2、4、8;第4组,层厚分别取2 mm、3 mm、4 mm. 结果 在四种不同扫描参数的比较中,b值为700 mm2/s的一级图像数较b值为400 mm2/s 和1000 mm2/s的多;方向为25时的一级图像数较方向为6和13的图像质量多;NEX为4的一级图像数较NEX为2和8的多;层厚为4 mm的一级图像质量较层厚2 mm和3 mm的多. 结论 b值为700 mm2/s、扩散敏感梯度方向数为25个、NEX为4和层厚为4 mm是颈髓DTI较好的扫描参数.

Study of the Parameters of Diffusion Tensor Imaging in Cervical Cord

Objective To evaluate parameters of diffusion tensor imaging (DTI) in the cervical cord.Materials and Methods DTI of the cervical cord was performed in 40 healthy adult volunteers.Different parameters including b value,number of the diffusion sensitive gradient direction,number of excitation and slice thickness were applied and the quality of the images was compared.In group 1,DTI in the cervical spinal cord was performed with different b-value including 400,700,and 1000 mm2/s.In group 2,DTI was completed with different number of diffusion gradient direction including 6,13,and 25.In group 3,DTI was performed with different number of excitation including 2,4,and 8.In group 4,DTI was completed with different slice thickness including 2 mm,3 mm,4 mm.Results DTI with b-value of 700 mm2/s was better than that with b-value of 400 mm2/s and 1000 mm2/s.DTI with 25 directions was superior to that with direction of 6 and 13.DTI with 4 excitations showed higher quality than that with 2 and 8 excitations.DTI with slice thickness of 4 mm was better than that with slice thickness of 2 mm and 3 mm.Conclusion DTI with b-value 700 mm2/s,25 diffusion gradient directions,4 excitations and a slice thickness of 4 mm was the better in DTI of the cervical cord.