Parameter analysis for diffusion tensor imaging corresponding to microstructural alterations following spinal cord injury

Diffusion tensor imaging (DTI) is a quantitative MRI technique that enables non-invasive, in vivo evaluation of spinal cord injury (SCI). Based on the anisotropy of water molecule diffusion, DTI provides superior detection of microstructural alterations compared with conventional MRI. Diffusion is quantified by parameters including fractional anisotropy (FA), apparent diffusion coefficient (ADC), average diffusion coefficient (DCavg), axial diffusion (AD), radial diffusion (RD), and mean diffusion (MD), each showing distinct temporal sensitivity to SCI. Changes in these indices reflect underlying tissue disruption and are closely correlated with neurological function in both experimental and clinical studies. Despite extensive investigations, a systematic summary of their diagnostic and prognostic value has been lacking. This review highlights parameter sensitivity at different injury stages and the associated microstructural changes. AD and DCavg demonstrated high sensitivity in the acute phase, whereas FA was particularly sensitive in the chronic phase. ADC and MD showed mild sensitivity in acute and subacute stages but became more relevant chronically, while RD exhibited low sensitivity in acute phase but progressively increased over time. Collectively, DTI provides critical diagnostic information, and cross-linked analysis of multiple metrics across time points enables more accurate evaluation of SCI severity and prognosis.