Applications of diffusion-weighted MRI in thoracic spinal cord injury without radiographic abnormality.

Diffusion-weighted MRI (DWI) has been proposed as a method to evaluate the integrity of white matter tracts in the spinal cord. The integrity of the spinal cord reflects the exact stage of traumatic injury. The purpose of this study was to evaluate the diagnostic value of DWI in SCIWORA in the thoracic spine. A total of five patients with thoracic SCIWORA underwent MRI and DWI within 48 h of injury. DWIs were obtained with a single-shot fast spin-echo (SSFSE) sequence; TI- and T2-weighted images were obtained with spin echo. Consistency among the clinical presentation, outcome, MRI and DWI was analysed. There was complete injury in one patient and partial in four patients. Four patients showed hypointense T1-weighted signal and hyperintense T2-weighted signal, and one patient had no changes on MRI. All patients showed hyperintense signal on DWI. Two patients made good recoveries (ASIA grades D and E), one had a moderate recovery (ASIA grade C), and two showed minimal or no improvement (ASIA grade A or B) in neurological function. Patients with no cord changes on MRI showed abnormal signals on DWI. It is likely that in the future DWI may provide important information complimentary to conventional MRI and allow a better prognostic evaluation of recovery from SCIWORA.