Correlation of diffusion tensor imaging and phase-contrast MR with clinical parameters of cervical spinal cord injuries.

STUDY DESIGN

This is a cross-sectional study.

OBJECTIVES

The goal of this study was to characterize the diffusion properties across segments of the spinal cord and peak cerebrospinal fluid (CSF) velocities in the stenotic spinal canal, and to determine the correlation between these properties and clinical and electrophysiological parameters in patients with cervical spinal cord injury (SCI).

SETTING

This study was conducted in the University teaching hospital.

METHODS

The study involved 17 patients with cervical SCI. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the spinal cord and peak systolic and diastolic velocities of CSF were measured at the level of maximum compression (region 1) and at the levels above (region 2) and below (region 3) the level of injury with no signal change in conventional magnetic resonance imaging. Neurological and electrophysiological parameters were measured, including American Spinal Injury Association (ASIA) Impairment Scale (AIS), ASIA motor score, ASIA sensory score, Modified Barthel Index, Spinal Cord Independence Measure III (SCIM III), somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP).

RESULTS

The ADC was significantly higher and the FA was significantly lower in regions 1, 2 and 3 of the SCI patients than in the normal controls (P<0.05 each). FA of the level below correlated with AIS, ASIA sensory score and SCIM III score, and FA of the level above correlated with SSEP latencies and MEP amplitudes (P<0.05 each). The reductions in FA correlated with CSF flow, functional measurements and evoked potentials.

CONCLUSIONS

Diffusion tensor imaging can be used to quantify the proximal and distal extents of spinal cord damage. Reductions in FA were correlated with CSF flow, functional measurements and evoked potentials.