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 University2 Radiology, Boston VA Healthcare System

3 Radiology, Boston Medical Center, Boston University School of Medicine

EP - 154

Introduction Methods Results Discussion Conclusion

☑ The authors have no conflict of interest to disclose with respect to this presentation.

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.

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

Introduction Methods Results Discussion Conclusion

• 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

Subjects

Introduction Methods Results Discussion Conclusion

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°

Imaging techniques

Introduction Methods Results Discussion Conclusion

Image analysis

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

• Images were reviewed by a single observer with special attention directed toward soft tissue changes

Introduction Methods Results Discussion Conclusion

STIRCTsoft

tissue window

A 74-year-old man with interspinous (arrows) and supraspinous (arrows) soft tissue injuries and prevertebral edema (arrowheads).

Evaluation for soft tissue injury: sagittal

Introduction Methods Results Discussion Conclusion

T2*

A 74-year-old man with interspinous (arrows) and supraspinous (arrows) soft tissue injuries and prevertebral edema (arrowheads).

Evaluation for soft tissue injury: axial

CT soft tissue window

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

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

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%)

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

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

Introduction Methods Results Discussion Conclusion

Soft tissue injury with spinal cord injury

Paraspinal soft tissue injury

Prevertebral edema

+ CT findings 59 18

Cord signal abnormality on

MRI37 13

Odds Ratio 1.9 (95% CI 0.9 to 3.7) 2.6 (95% CI 0.9 to 7.6)

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).

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.

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).

STIR

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

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

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

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.)

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

Introduction Methods Results Discussion Conclusion

Introduction Methods Results Discussion Conclusion

• 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.

Conclusion

Introduction Methods Results Discussion Conclusion

• 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.

References

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