Cervical Spine Trauma Assessed with MR Diffusion Tensor Imaging
New research indicates that changes in diffusion tensor imaging parameters may be a reflection of the severity of injury to the cervical spine. Moreover, this imaging modality detects the site of injury; changes are most marked in the area that was injured. DTI may capture injury otherwise missed with conventional MRI or CT.
A research team from the University of Maryland Medical Center in Baltimore (UM-B) conducted a retrospective record review of 50 patients who presented with symptomatic neck trauma. They also reviewed data from 11 patients that served as controls. All the participants underwent MR DTI scans.
Some patients with cervical spine trauma do not show signs of injury captured with standard MR or CT scans. However, those patients may have MR diffusion tensor imaging (DTI) that notes injury. DTI is able to capture damage to white matter fibers in the brain, wherein blood flows isotropically. This characteristic is referred to as relative and/or fractional anisotropy. This sort of injury also impedes the flow of extracellular water molecules, there is less available room for movement. This characteristic, the apparent diffusion coefficient (ADC) is also seen on DTI.
The researchers classified each of the patients into one of four categories based on the findings with conventional MRI: normal CT with no cord contusion, abnormal CT with no cord contusion, no hemorrhage with cord contusion, and hemorrhage with cord contusion.
Overall, patients had lower whole cord values for ADC compared to the controls. However, there were no differences in whole-spine fractional anisotropy. Differences were noted at the actual sites of injury, instead.
Patients had significantly lower fractional anisotropy and ADC scores compared to controls at the injury site. The most dramatic differences in fractional anisotropy, volume ratio, whole-cord ADC, and relative anisotropy was found in the cohort of patients who had hemorrhagic cord contusions, all which were statistically significant. The change in ADC was associated with the level of injury.
November 30, 2007 Related topics: Imaging, Diagnostic, Radiology, Psychiatry & Neurology