MRI in traumatic spinal cord injury: a single national spinal centre experience and study of imaging features with clinical correlation with ASIA score and outcome Poster No.: C-1235 Congress: ECR 2011 Type: Scientific Paper Authors: G. C. Colleran, A. Walsh, H. Heneghan, R. Gunapala, A. Craddock, E. Smith, A. Poynton, E. C. Kavanagh, L. Lawler; Dublin/IE Keywords: DOI: Musculoskeletal spine, Spine, Emergency, MR, MR-Diffusion/ Perfusion, Audit and standards, Trauma 10.1594/ecr2011/C-1235 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 13
Purpose Spinal injury is very common in Ireland: 19 per 100,000 (1). It poses a significant disease burden. We aim to discuss Spinal Cord Injury (SCI) in the context of: 1. Background/Demographics: overall disease burden. 2. MR techniques in 2011. 3. The value of individual MRI imaging features in the diagnosis, classification and prognosis of SCI. Clinical neurological assessment of spinal cord injury is based on the ASIA score which represents a standardised approach to SCI and identifies the most caudal normal neurological level as well as defining the extent of the sensory and motor deficit. The has important prognostic implications. Neurological examination and findings on diagnostic imaging determine the need for surgical intervention and stabilisation of unstable spinal injuries which could result in the development of abnormal neurology following physiological weight-bearing activities. Diagnostic imaging in our Spinal centre is multi-modality involving a combination of plain film, computed tomography and magnetic resonance imaging. We hypothesize that there is a correlation between MRI findings and ASIA score and that select features may have a role in predicting clinical outcome. Images for this section: Page 2 of 13
Fig. 1: Sagittal T2 lumbar spine: Two level injury: The obvious abnormality at L2 may cause the unwary to miss the fracture and abnormal alignment at S1/S2. Page 3 of 13
Fig. 2: T2 Sagittal image demonstrating: Anterolisthesis of C6/C7. Page 4 of 13
Fig. 3: The anterior longitudinal ligament is torn with haemorrhage demonstrated beneath the torn ligament, there is anterolisthesis with abnormal configuration of the posterior longitudinal ligament and abnormal signal in the cord. Page 5 of 13
Fig. 4: Axial imaging in the cervical spine demonstrating abnormal high signal in the cord and a focal area of low signal representing acute haemorrhage which is an adverse prognostic indicator. Page 6 of 13
Methods and Materials A retrospective review was performed of all out-of-hours emergency MRI spines performed in the Mater Spinal Unit between 01/02/200 and 21/3/2010. Institutional Ethics was obtained. The MRI log book was reviewed and the cases ascertained. All cases were reviewed on an OSIRIX platform. A table for interpretation was designed. 2 radiologists (A Consultant Radiologist with significant MRI experience and a second year SpR post part 1 of the FFR RCSI) blinded to clinical findings and outcome reviewed and interpreted findings by consensus. Emergency out of hours MRI Technique: At a minimum patients had sagittal T1 and T2 imaging performed +/- inversion recovery sequences. Axial T1,T2 were performed at the appropriate levels. Statistical analysis was carried out using SPSS 17.0. The chi square test was used for binomial comparisons when appropriate. ANOVA, followed by Tukey HSD Post Hoc test, was used to compare the mean response between subject factors of interest. Two-sample t-test was used for any two sample comparisons. Correlation analysis was performed using Pearson's correlation coefficient. All tests were two tailed and results with a p<0.05 were considered statistically significant. Results 66 patients underwent emergency our of hours MRI during the study period and the images were reviewed as decribed. Page 7 of 13
Falls were the commonest mechanism of injury. MRI findings and correlation with poor neurological upper limb outcome as assessed by independent ASIA score: Cord haemorrhage: Significant association, p<0.001. Signal change: Significant association, p = 0.013. Column alignment: Significant association, p=0.01. MRI findings and correlation with poor neurological lower limb outcome as assessed by independent ASIA score: Lower extremity Signal Intensity: Motor: No association (p = 0.437). Sensory: No association ( p=0.550, PP p=0.483). Length of Signal Change: Motor: No correlation (p=0.41). Sensation: significant correlation (p=0.009). Cord Haemorrhage: No motor / sensory correlation. Column Alignment: No motor/sensory correlation. Older people were more likely to have abnormal alignment. p=0.021, t-test. Soft tissue: Motor: No association, (p=0.111, t-test). Sensory: Significant association with light touch (p=0.015, t-test). Page 8 of 13
Images for this section: Fig. 1: Axial imaging in the cervical spine demonstrating abnormal high signal in the cord and a focal area of low signal representing acute haemorrhage which is an adverse prognostic indicator. Page 9 of 13
Fig. 2: Sagittal T2 of the cervico-thoracic region: fractures of T4, T5 and T7 demonstrated. Page 10 of 13
Fig. 3: Sagittal T2 of the thoracolumbar spine demonstrating a T12 fracture with resultant severe spinal canal stenosis, abnormal high signal in the cord with central low signal representing acute cord haemorrhage. Page 11 of 13
Fig. 4: Sagittal T2 of the cervical spine demonstrating retrolisthesis of C5 on C6 with a torn posterior longitudinal ligament, abnormal high signal in the cord with focal low signal representing haemorrhage. Page 12 of 13
Conclusion The majority of diagnostic information was obtained from the T2 sagittal sequence. T1 imaging demonstrates the basic anatomy well but makes a minimal contribution. Cord haemorrhage, signal change and abnormal alignment are predictive of a low ASIA score and identifies the sub-group of patients most likely to have a poor neurological outcome. Given the prognostic importance of haemorrhage we advocate the addition of a sagittal gradient echo sequence to increase the sensitivity for haemorrhage. References Epidemiology of spine trauma in an Irish regional trauma unit: a 4-year study. Roche SJ, Sloane PA, McCabe JP. Injury. 2008 Apr;39(4):436-42. Spine trauma. Looby S, Flanders A. Radiol Clin North Am. 2011 Jan;49(1):129-63 Personal Information Author for correspondance: Dr Gabrielle Colleran, SpR Diagnostic Radiology, Mater Misericordiae University Hospital, Eccles Street, Dublin 7. E-mail: collerangabrielle@hotmail.com Page 13 of 13