Evaluation for Soft Tissue Injuries on CT in Acute Cervical Spine Trauma

1. EP - 154 Evaluation for Soft Tissue Injuries on CT in Acute Cervical Spine Trauma with MR Imaging Correlation Naoko Saito 1, Margaret N Chapman 2,3, Akira Uchino 1 Fumikazu Sakai 1,Osamu Sakai 3 1 Radiology, Saitama International Medical Center, Saitama Medical University 2 Radiology, Boston VA Healthcare System 3 Radiology, Boston Medical Center, Boston University School of Medicine

2. Introduction Methods Results Discussion Conclusion ☑ The authors have no conflict of interest to disclose with respect to this presentation.

3. Introduction Methods Results Discussion Conclusion • Soft tissue injuries, including ligamentous injury, muscular injury, and prevertebral edema/hematoma, are common imaging findings of cervical spine trauma. • These injuries are believed to correlate with the severity of the spinal cord injury. (Song KJ, et al. Martínez-Perez R et al. Goradia D et al.) • Although MR can clearly demonstrate these injuries, the utility of CT in their detection is often underappreciated.

4. Introduction Methods Results Discussion Conclusion Purpose • To assess whether CT with soft tissue window can help identify soft tissue injuries • To compare CT with MR imaging findings in patients with acute cervical spine trauma

5. Retrospective imaging review From January 2010 to November 2014 Patients who underwent both CT and MR imaging of cervical spine for acute traumatic spinal injury were identified Medical records were reviewed for demographics and admitting diagnosis The indication for MRI at our institution Neck pain, midline cervical pain Neurological deficits on examination Subjective neurological complaints Altered mental status Introduction Methods Results Discussion Conclusion Subjects

6. CT imaging 64-slice MDCT (LightSpeed VCT, GE Healthcare) Reviewed in bone (WL/WW: 350/1500) and soft tissue (WL/WW: 55/450) windows MR imaging 1.5 MRI (MAGNETOM Avanto, SIEMENS) Reviewed in T1, T2-weighted, and STIR images Sagittal T1 weighted image: TR/TE 550/10 Sagittal T2 weighted image: TR/TE 3500/85 Sagittal STIR： TR/TE 5000/60, TI 170 Axial gradient-recalled image: TR/TE 500/24, FA 30° Introduction Methods Results Discussion Conclusion Imaging techniques

7. Introduction Methods Results Discussion Conclusion Image analysis • Images were reviewed by a single observer with special attention directed toward soft tissue changes • CT • Fracture • Dislocation • Soft tissue abnormality • Interspinous soft tissue • Supraspinous soft tissue • Prevertebral soft tissue • Posterior cervical musculature • MRI • Fracture • Dislocation • Soft tissue abnormality • Interspinous soft tissue • Supraspinous soft tissue • Prevertebral soft tissue • Posterior cervical musculature • Spinal cord abnormality

8. Introduction Methods Results Discussion Conclusion Evaluation for soft tissue injury: sagittal CT soft tissue window STIR A 74-year-old man with interspinous (arrows) and supraspinous (arrows) soft tissue injuries and prevertebral edema (arrowheads).

9. Introduction Methods Results Discussion Conclusion Evaluation for soft tissue injury: axial CT soft tissue window T2* A 74-year-old man with interspinous (arrows) and supraspinous (arrows) soft tissue injuries and prevertebral edema (arrowheads).

10. Introduction Methods Results Discussion Conclusion Patient characteristics • 157 patients with acute cervical spine trauma were identified during the 5-year period • Age: 14 - 92 (avg. 59.5) years old • Gender: 34 women, 123 men • Mechanism: Fall 108, MVC/MCA 45, others 4 • MVC = motor vehicle collision, MCA = motorcycle accident • Days between CT and MR: 0-26 (avg. 1.2) days

11. Introduction Methods Results Discussion Conclusion Patient characteristics • 157 patients with acute cervical spine trauma were identified during the 5-year period • Fracture 52 patients • MR imaging abnormality • Spinal cord injury 83 patients • Paraspinal soft tissue injury 92 patients

12. Introduction Methods Results Discussion Conclusion Soft tissue abnormalities • Out of 157 patients, • 59 patients (37.6%) showed abnormalities in the paraspinal soft tissues on CT • 92 patients (58.6%) showed abnormalities in the paraspinal soft tissues on MR imaging • Of 92 patients with paraspinal soft tissue injuries by MR, • CT identified the abnormalities in 57 patients (62.0%)

13. Introduction Methods Results Discussion Conclusion Soft tissue abnormalities • Of 59 patients with paraspinal soft tissue abnormalities on CT, • 38 patients (64.4%) demonstrated the abnormalities adjacent to the fractures • 18 patients (15.3%) showed prevertebral edema • Of 18 patients with prevertebral edema on CT, • 12 patients (66.7%) had cervical spine fractures

14. Introduction Methods Results Discussion Conclusion Soft tissue injury with spinal cord injury • Of 59 patients with paraspinal soft tissue abnormalities on CT, • 37 patients (62.7%) had spinal cord signal abnormalities on MR imaging • 11 patients (18.6%) did not have fracture or dislocation but had spinal cord abnormalities on MR imaging • Of 18 patients with prevertebral edema on CT, • 13 patients (72.2%) had spinal cord injury on MR imaging

15. Introduction Methods Results Discussion Conclusion Soft tissue injury with spinal cord injury

16. Introduction Methods Results Discussion Conclusion Representative case 1 • Soft tissue injury with fracture and spinal cord injury. A 75-year-old man after a fall from 16 stairs presented with lost of consciousness. STIR There is a posterior spinous process fracture of C4 (arrows). CT with soft tissue window shows fat stranding within the intraspinous soft tissues (arrow) adjacent the to fracture. STIR image demonstrates intra- and supraspinous soft tissues injuries (arrows) and spinal cord injury with hemorrhage at the level of C4/5 (arrow).

17. Introduction Methods Results Discussion Conclusion Representative case 2 • Prevertebral edema with spinal cord injury. A 73-year-old woman after a fall from standing presented with quadriplegia. STIR There is no fracture on CT. CT with soft tissue window shows prevertebral edema (arrowheads) and fat stranding within the intra- and supraspinous (arrows) soft tissues, correlating with STIR image. Spinal cord injury at the level of C2-5 is seen (arrow).

18. Introduction Methods Results Discussion Conclusion • Evaluation for soft tissue injuries in acute cervical spine trauma • Soft tissue injuries are believed to correlate with the severity of the spinal cord injury • Could be useful in predicting neurologic outcome (Song KJ, et al. Martínez-Perez R et al. Goradia D et al.) • Ligamentous injury: anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum • MR imaging has been reported as clearly superior to CT in detecting soft tissue injuries • Utility of CT in their detection is often underappreciated

19. Introduction Methods Results Discussion Conclusion • Evaluation for soft tissue injuries on CT • CT identified approximately 2/3 of the soft tissue abnormalities observed on MR imaging • CT findings of soft tissue abnormality: • Fat stranding within the interspinous and supraspinous regions • Posterior cervical musculature swelling • Prevertebral soft tissue swelling • These CT findings may be associated with ligamentous injuries • Soft tissue abnormalities were often seen adjacent to the fractures on CT • Evaluation with soft tissue window could help to detect subtle fractures

20. Introduction Methods Results Discussion Conclusion • Evaluation for soft tissue injuries on CT • About 60% of the patients with paraspinal soft tissue abnormality on CT had spinal cord injury on MR imaging • Furthermore, approximately 20% of those patients did not have fracture or dislocation • Evaluation of paraspinal soft tissue abnormality on CT could also be useful in predicting neurologic outcome

21. Introduction Methods Results Discussion Conclusion • Patients with prevertebral edema on CT were more likely to have spinal cord injury • Prevertebral edema is thought to be associated with more severe cervical spine trauma • Prevertebral edema/hematoma • Occurred mainly in hyperextension and whiplash injuries(Hutter G et al.) • Disruption of the anterior ligaments • Fractures of the anterior bony elements • Occurred in the elderly or anticoagulated patients(Hutter G et al.) • Caused by high-energy trauma in younger patients(Kuhn JE et al.)

22. Introduction Methods Results Discussion Conclusion • Limitations • Evaluation for soft tissue on CT • Beam hardening artifacts • Retrospective nature • Time difference between CT and MR examinations • Sampling bias • A single observer • Correlation of surgical findings or clinical outcome • Future study

23. Although MR imaging is highly sensitive for detecting ligamentous and paraspinal soft tissue injuries, CT with soft tissue window can also demonstrate paraspinal soft tissue abnormalities in patients with acute cervical spine injury. Patients with soft tissue abnormalities, especially prevertebral edema on CT, are 3 times more likely to have spinal cord injuries. Introduction Methods Results Discussion Conclusion Conclusion

24. Martínez-Perez R, Paredes I, Cepeda S, et al. Spinal Cord Injury after Blunt Cervical Spine Trauma: Correlation of Soft-Tissue Damage and Extension of Lesion. AJNR Am J Neuroradiol. 2014;35:1029-34. Hutter G, Benz R, Taub E, et al. Extensive cervical prevertebral hemorrhage with airway obstruction after low-energy hyperextension injury. Injury Extra 2014;45:53-55. Tan LA, Kasliwal MK, Traynelis VC. Comparison of CT and MRI findings for cervical spine clearance in obtunded patients without high impact trauma. Clin Neurol Neurosurg 2014;120: 23–26. Song KJ, Kim GH, Lee KB. The efficacy of the modified classification system of soft tissue injury in extension injury of the lower cervical spine. Spine 2008;33:E488–93. Goradia D, Linnau KF, Cohen WA, et al. Correlation of MR Imaging Findings with Intraoperative Findings after Cervical Spine Trauma. AJNR Am J Neuroradiol. 2007;28:209-15. Kuhn JE, Graziano GP. Airway compromise as a result of retropharyngeal hematoma following cervical spine injury. J Spinal Disord 1991;4:264-9. Introduction Methods Results Discussion Conclusion References Thank you!