Diffusion Tensor Imaging and 3D Tractography of the Cervical Spinal Cord Using the ECG-Gated Line-Scan Technique

Diffusion tensor (DT) magnetic resonance (MR) imaging in addition to conventional MR images provide valuable information on the brain. This study compared line scan DT imaging with and without the ECG-gating technique to estimate clinical usefulness of the line scan diffusion tensor image (LSDTI) with ECG-gating in evaluating spinal cord diseases in vivo. First, five healthy volunteers participated in the comparison study. LSDWI was performed in three to five sagittal sections with a pulsed-field-gradient diffusion preparation pulse employing two different b-values (0 and 700 s/mm²) along six directions. Apparent diffusion coefficient (ADC) maps and fractional anisotropy (FA) were calculated and three-dimensional tract reconstruction and color schemes of the spinal cord were obtained. Image quality and the acquisition time of each LSDTI were compared. Second, LSDTI with ECG-gating was performed in eighteen patients with cervical spinal cord disorders and evaluated by two neuroradiologists. Images with the ECG-gated technique were all superior to those without ECG—gating. Mean extended time for LSDTI with ECG-gating was approximately two minutes. In clinical use, the ADC and FA of spinal cord in patients with cervical spondylotic myelopathy statically changed. Moreover, demonstration of fibers was correlated with clinical symptoms. ECG-gating technique is preferable to LSDTI. The ADC and FA measurements and 3D fiber tracking of LSDTI with ECG-gating are promising methods to estimate cervical spinal cord pathology in clinical use.