Susceptibility weighted imaging in detecting hemorrhage in acute cervical spinal cord injury.

BACKGROUND AND PURPOSE

Susceptibility weighted imaging (SWI) is sensitive to deoxyhemoglobin and blood products such as hemosiderin in detecting microbleeds in the brain. However, there are no studies on SWI in the spine cord injury so far. The purpose of this study was to evaluate the role of SWI in detecting hemorrhage in acute cervical spinal cord injury (SCI).

MATERIALS AND METHODS

Twenty-three patients with a history of acute cervical spine trauma were studied. High-resolution SWI, gradient-echo (GRE) T2* weighted-image (T2WI) and conventional magnetic resonance imaging (MRI) were performed on all patients within 15 days of the onset of injury. On the basis of the MRI findings, the patients were classified into four patterns: normal cord, spinal cord edema, spinal cord contusion and spinal cord hemorrhage. Quantitative analysis was performed by calculating and comparing the signal ratio of the hemorrhage to normal spinal cord on the same slice of T2WI and SWI. All patients were clinically evaluated in follow-up. Twenty volunteers were also scanned as a control group.

RESULTS

Out of 23 patients with a history of acute cervical spine trauma, 4 patients showed normal spinal cord on both conventional MRI and SWI, 8 had only spinal cord edema and 5 had contusion on conventional MRI, but SWI showed hemorrhage in 2 of the 5 patients with spinal contusion on conventional MRI; the other 6 patients had intraspinal hemorrhage on conventional MRI, and SWI proved hemorrhage in all these 6 patients. There was a significant difference between the signal ratios of hemorrhage to normal tissue on T2*WI and SWI (Z=2.34, P=.02).

CONCLUSION

Susceptibility weighted imaging is more sensitive than conventional MRI in detecting hemorrhage in acute cervical SCI. This technique could prove to be a useful tool in the routine evaluation of cervical SCI patients.