The Role of Diffusion Tensor Imaging and Diffusion Tensor Tractography in the Assessment of Acute Traumatic Thoracolumbar Spinal Cord Injury

Abstract

Background: This study explored diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) to assess the prognosis of thoracolumbar spinal cord injury (SCI).

Methods: Twenty patients with acute traumatic thoracolumbar complete SCI (T1-L1, American Spinal Injury Association Impairment Scale [AIS] grade A) underwent conventional magnetic resonance imaging and DTI examinations. DTI measured the fractional anisotropy (FA) and apparent diffusion coefficient adjacent to the lesion epicenter. DTT was used to detect the white matter fiber morphology and measure the imaginary white matter fiber volume and connection rates of fiber tractography (CRFT). The patients' neurological functions were evaluated by the AIS grades.

Results: At the final-follow-up, among the 20 patients with AIS grade A, 15 maintained the AIS grade (group A), and 5 patients showed improvement of AIS grade (group B). Group A's mean FA value was significantly lower than that of group B, whereas the mean apparent diffusion coefficient value among the 2 groups showed no significant difference. The white matter fibers of most patients in group A were completely ruptured (11/15), but the white matter fibers of all patients in group B were retained in different number (5/5). The mean CRFT of group B was significantly higher than that of group A (P < 0.05). The improvement of AIS grade was slightly positively correlated with FA values and highly positively correlated with CRFT.

Conclusions: The prognosis of complete thoracolumbar SCI may be related to the FA value and the CRFT. The application of DTI and DTT may optimize the diagnosis of thoracolumbar SCI.

Keywords: Connection rates of fiber tractography; Diffusion tensor imaging; Diffusion tensor tractography; Magnetic resonance imaging; Thoracolumbar spinal cord injury.