Diagnostic and prognostic role of MRI in spinal trauma, its comparison and correlation with clinical profile and neurological outcome, according to ASIA impairment scale

Abstract

Aims and objectives: To evaluate the role of magnetic resonance imaging (MRI) as a non-invasive diagnostic tool in patients with acute and chronic spinal trauma and to compare and correlate the MRI findings with those of patients' clinical profile and neurological outcome according to ASIA impairment scale to assess prognostic and clinical value of MRI.

Materials and methods: Sixty two patients of spinal trauma formed the study group in a prospective fashion. The patients undergoing MR imaging and magnetic resonance images were analyzed and correlated with findings on neurological examination according to American Spinal Injury Association (ASIA) impairment scale (AIS) at the time of MRI examination and subsequently at sub-acute interval to assess neurological outcome.

Statistical analysis: Sample profile was described in terms of 95% confidence limit and proportion. To describe strength of association between extent of spinal cord injury and outcome, odd's ratio, bivariate and multi variant analysis, was used. Pearson's chi square (χ) (2) statistics was applied to test the association between two categorical variables. Data were analyzed using statistical software package, STATA 9.2 and the difference was considered to be significant if 'P' value was <0.05.

Observation and results: The cord edema without hemorrhage was the most common MR finding (41.5%). The others were sizable focus of hemorrhage within the cord (33%), epidural hematoma (5.0%), and normal cord (26%). Majority of MR findings correlated well with clinical profile of the patient according to ASIA impairment scale. This study demonstrated that patients with presence of sizable focus of haemorrhage had larger cord edema and more severe grade of initial ASIA impairment scale( AIS) with poor recovery at follow up (P=0.032).Improvement in upper extremity was more than lower extremity. Severe cord compression was also associated with poor neurological outcome; however it was not statistically significant (P=0.149).

Conclusions: With this study the authors concluded that various MRI findings in acute spinal cord injury correlated well with the initial clinical findings and on follow-up according to ASIA impairment scale. MRI is useful for initial diagnosis of acute spinal cord injury and its prognostication for predicting neurological recovery.

Keywords: ASIA impairment scale; MRI; acute spinal cord injury; prognostication; spinal trauma.

Figure 1

The patient presented with h/o fall from height 1 day prior to date of MRI. T2 sagittal (a) and T2^*-GRE (b) MR images reveal fracture dislocation at C6–7 level with grade 4 spondylolisthesis of C6 over C7 with fracture of C6 and D3 and contusion of cord involving about 6.1 cm long segment with sizable focus of hemorrhage with severe cord compression. On clinical exam AIS at admission was A, on discharge no improvement was noted. Thus involvement of long segment of cord, presence of sizable focus of hemorrhage with severe cord compression were bad prognostic indicator for high-grade AIS at admission and no recovery of patient at discharge

Figure 2

History of fall of weight over the patient 7 days prior to MRI examination. Sagittal T2W MR image shows anterior wedge collapse of L1 vertebral body with cord edema in the region of conus in about 1.4 cm span. Clinical examination showed initial AIS D, patient was followed till discharge. No improvement was noted as initial AIS was good. Involvement of small segment of cord, absence of cord hemorrhage and severe cord compression were good prognostic indicator for the patient

Figure 3

Alleged history of fall from height 4 days prior MRI. Sagittal T2W MR imaging reveals partial wedge collapse of C5 vertebra with grade 2 spondylolisthesis at C5-6 level with cord contusion in 5.8 cm span extending from C4 to C8 vertebral level. On clinical exam at admission the AIS was C, patient was followed till discharge. The AIS at discharge was D s/o improvement. Absence of hemorrhage was good prognostic indicator for the recovery of the patient. The long segment of cord involved was responsible for high-grade AIS at admission

Figure 4

Patient presented with history of fall from height 1 day prior to date of MRI. Sagittal T2W MR imaging shown fracture dislocation at D4–5 level with grade 4 spondylolisthesis of D4 over D5 with fracture of D5, contusion of cord in about 3.4 cm span , a small focus of hemorrhage in cord (8 mm), a small epidural hematoma and severe cord compression. On clinical exam AIS at admission was A. Patient was followed till discharge, no improvement was noted. Presence of long length of cord involved severe cord compression and were responsible for high-grade AIS at admission and discharge.