Dr. Ahmed Refaey

1. Imaging of cervical spine Dr. Ahmed Refaey MBBCh, MS, FRCR

2. 3% of MVA patients , have cervical spine injury • 10-20% patients with head injury, have also cervical spine injury • Most cervical spine fractures occur at two levels • 17% of patients have a missed or delayed diagnosis with a risk of perminant neurologic damage • 1/3 of injuries occur at level of C2 and ½ occur at level of C6-C7

3. The NEXUS criteria state that a patient with suspected cervical spine injury can be cleared providing the following: *- no posterior midline cervical spine tenderness *- no evidence of intoxication is present *- patient has a normal level of alertness *- no focal neurologic deficit

4. Plain films • 3 views should be taken : - true lateral view ( must include all 7 cervical vertebrae as well as the C 7 – T1 junction ) - an AP view - an open mouth (odontoid view)

5. The lateral view … • The lateral view is the most useful view, approximately 85-90 % of spinal injuries are evident on this view • Should be obtained & examed before any other films are taken • All 7 cervical vertebrae and the C7-T1 junction must be visualized because the cervicothoracic junction is a common place for traumatic injury

7. Is this an adequate lateral film?

8. AP & odontoid view • If lateral view is normal, proceed with AP & odontoid views • Patient should be maintained in cervical immobilization and plain films or CT scans obtained untill all vertebrae are clearly visible.

10. Anatomy

11. Lateral view

12. AP view

13. Odontoid view

14. Alignment

15. Systematic approach: * check alignment by following 3 contour lines - anterior contour line - posterior contour line - spinolaminar contour line

16. These lines should follow a slightly lordotic curve, smooth and without step-offs. • Any malalignment should be considered evidence of ligamentous injury or occult fracture and cervical spine immobilization should be maintained untill a definitive diagnosis is made.

17. AP view • Alignment should be evaluated using the edges of vertebral bodies and articular pillars • Hight of vertebral bodies should be equal • Hight of joint space should be equal • Spinous process should be in midline, if displaced to one side , a facet dislocation should be suspected.

18. Odontoid view • The distance from the dens to lateral masses of C1 should be equal bilaterally. • Any asymmetry is suggestive of a fracture of C1 or C2 • Lateral mass of C1 should line up with lateral margins of supriorarticular facet of C2. if not, a fracture of C1 is suspected.

19. Prevertebral space • Nasopharyngeal space {C1} -- 10 mm in adult • Retropharyngeal space {C2-C4} -- 5-7 mm • Retrotracheal space {C5-C7} -- 14mm in children -- 22 mm in adults

20. Prevertebral soft tissue swelling is important as it is usually due to hematoma 2ry to occult fractures • Soft tissue swelling in symptomatic patient should be considered an indication for further radiographic evaluation

22. CT

23. CT • 20% of fractures are missed on plain radiographs • Useful in fractures that result in neurologic deficit and in fractures of posterior elements ( e.g. Jefferson’s fracture)

24. Advantages of CT • Excellent in identifying osseous compromise of the vertebral canal • Visualization of subtle fractures • Provides patient comfort by being able to reconstruct images in axial , sagittal , coronal planes and 3D from one patient position. • Soft tissue window & bone window

25. ****** limitations: * unable to show ligamentous injuries * relatively high costs

26. Excellent in identifying osseous compromise of the vertebral canal

27. Visualization of subtle fractures

28. Provides patient comfort by being able to reconstruct images in axial , sagittal and coronal planes from one patient position as well as 3-d reconstruction

29. Soft tissue window & bone window

35. MRI

36. MRI • Advantages: * excellent soft tissue contrast, making it the study of choice for spinal cord survey , hematoma and ligamentous injuries. * good general overview because of its ability to show informations in different planes * ability to demonstrate vertebral arteries which is useful in evaluating fractures involving the course of vertebral arteries * no ionizing radiation

37. MRI • Disadvantages * loss of bony details * high cost - patients with pacemakers and certain ferromagnetic materials ( aneurysm clips ) are not able to be scanned

39. MRI diagnostic values • Spinal cord lesions • Bone marrow pathology • Ligamentous injuries • soft tissue edema

40. MRI • T1W – display anatomic details • T2W – display pathologic changes better • Together – enable detection & characterization of most lesions

43. Stability

45. Spinal stability is depending on at least two intact columns. • When two of the three columns are disrupted , it will allow abnormal segmental motion.

46. Spinal cord injury • Two types: * non-hemorrhagic: only high signal on T2W * hemorrhagic: areas of low signals on T2W within the area of edema

47. Hemorrhagic spinal cord injury has an extremely poor outcome

48. Mechanism of injury

49. Hyperflexion Hyperextension Compression

50. Hyperflexion ……. • Excessive flexion of neck in sagittal plane • Diving in shallow water • Flexion tear drop fracture