Toward Reproducible Tract-Specific in Vivo Diffusion Quantification in Human Cervical Spinal Cord

Junqian Xu¹, Eric C. Klawiter¹, Joshua S. Shimony², Abraham Z. Snyder, ¹², Robert T. Naismith¹, Agus Priatna³, Tammie Benzinger², Anne Cross¹, Sheng-Kwei Song²

We describe a reproducible in vivo human cervical spinal cord diffusion tensor imaging (DTI) protocol at 3T. The data acquisition and analysis procedures are described with examples from healthy (n = 17) and pathological human spinal (n = 2) cords. The described comprehensive approach (1) accounts for the natural curvature of the human spinal cord by covering C1-6 with separate tiltable slices/groups, (2) minimizes distortion and signal drop-out by localized shimming, (3) improves the robustness by motion-correction and motion-based outlier rejection, (4) corrects negative eigenvalues by non-negative non-linear DTI calculation, and (5) employs objective geometry based region-of-interest selection for tract identification.