1. Magnetic resonance imaging of spinal cord trauma: a pictorial essay
Neuroradiology (2006) 48: 223–232
Int.阮威勝

2. Introduction
Fractures and joint dislocations can be detected accurately by plain radiology or CT
Imaging the spinal cord is more difficult
spinal cord injury can occur in the absence of bone changes
The focus of this review is the role of magnetic resonance imaging (MRI) in the assessment of spinal cord injury following trauma, in both the acute and the chronic stages

3. Acute Spinal Cord Injury

4. true cord injury or compression with secondary cord damage
minor injury or more severe trauma
five criteria for a minor injury : “five no’s”
no focal neurological signs
no midline spinal tenderness
no intoxication
no painful injury
no depression of consciousness
complete or incomplete lesions
A complete lesion involves loss of both functions in the
lower sacral segments.

5. Central cord syndrome
Trauma to the mid cervical and lower cervical spinal cord
Degenerative bone changes are often present
Greater motor impairment in the upper rather than the lower extremities
bladder dysfunction and varying degrees of sensory loss below the level of the lesion

6. Anterior cord syndrome
Secondary to a disruption of the anterior spinal artery
Typically affects the upper thoracic cord
Predominant motor loss with absent or insignificant sensory deficit

7. Brown-Séquard syndrome
Hemisection of the spinal cord
Ipsilateral weakness and loss of proprioceptive and vibratory sensation, due to disruption of the corticospinal tracts and dorsal columns
Pain and temperature sensation are lost on the contralateral side because of the affected spinothalamic tract.

8. Cauda equina syndrome Trauma at the level of the cauda equina
Difficulty in walking due to weakness of the legs
Sensory disturbance, characteristically found in the perineal region

9. Spinal cord injury without radiographic abnormality (SCIWORA)
Paediatric population
Relatively large head size and skeletal mobility of the neck of younger children
Can also occur in adults

10. Clinical evaluation can be difficult and that imaging is of particular importance in evaluating these patients
MRI is the modality of choice for the evaluation of patients with neurological signs or symptoms
Even in the absence of a traumatic lesion on either of these examinations, emergency MRI is indicated and should be obtained as soon as possible and certainly within the first hours after injury to prevent irreversible damage to the spinal cord.

11. In the acute setting, MR images can show transection, haemorrhage, contusion or oedema of the spinal cord
Oedema or contusion is seen after secondary temporary or permanent cord compression
Intramedullary haemorrhage is usually associated with a clinically complete and irreversible spinal cord injury

12. Spinal cord oedema
Crushed vertebra
Sagittal TSE T2WI

13. Traumatic pseudomeningocele
STIR
Sagittal TSE T2WI
Axial GE T2WI

14. Spinal cord haematoma
Axial GE T2WI
Sagittal GE T2WI

15. Axial SE T1WI
Sagittal TSE T2WI
Axial GE T2WI

16. MRI can demonstrate ligamentous injuries, muscular lesions, facet joint dislocations and bone marrow oedema
MRI is sensitive and has a high negative predictive value in the assessment of ruptured ligaments

17. In injury to the upper cervical level, the tectorial membrane can be disrupted
The tectorial membrane lies close to the dens and clivus as an extension of the posterior longitudinal ligament
The integrity plays a crucial role in the stability of the upper cervical region.

19. Detachment of the tectorial membrane
Sagittal TSE T2WI

20. MRI as Prognostic role Poor prognosis
complete cord syndrome and abnormal MRI finding
cord contusion (cyst formation)
pre-existing degenerative changes
presence and extent of spinal cord haematoma

21. Good prognosis partial cord syndrome and normal MRI findings
absence of spinal cord oedema
The ratio of the maximal anteroposterior diameter of an epidural haematoma to the spinal canal diameter may have prognostic value
Ratios of less than 60% are associated with a full recovery

22. Pre-existing cervical spondylosis and spinal stenosis
Sagittal TSE T2WI
Sagittal TSE T2WI
Turbo STIR

23. Epidural haematoma
Axialal TSE T2WI
Sagittal TSE T2WI
Sagittal SE T1WI

24. SCIWORA
Sagittal SE T1WI
Turbo STIR

25. Chronic Spinal Cord Injury

26. A number of victims of spinal cord trauma may develop new symptoms several weeks or years later
MRI is unequivocally the modality of choice in the diagnostic work-up of these patients

27. Posttraumatic syringomyelia
3–4%.
8 weeks ~ several years
Caused by cystic degeneration of the injured spinal cord at or near the site of the trauma
Clinical presentation is non-specific
Ascending sensory signs and motor deficit
Treatment：shunting

28. Non-communicating syringomyelia
often associated with a Chiari malformation, spinal stenosis or basilar impression
Communicating syringomyelia
mainly seen in children and always associated with hydrocephalus.

29. A benign widening of the central canal occurs in approximately 1.5 %
Syringomyelia must be differentiated from the “benign” widening of the central canal
typically seen at the junction of the anterior one-third and the posterior two-thirds of the spinal cord and is generally not wider than 2–3 mm
A benign widening of the central canal occurs in approximately 1.5 %

30. High-pressure and low-pressure syringomyelia
No non-invasive method of distinguishing the two states, but MRI appears to display a flow void within the cavity of a high-pressure syrinx on T2-weighted images.
High-pressure syrinx may correspond to an acute expanding syrinx that, following prompt treatment, is more likely to improve than the low-pressure syrinx

31. Posttraumatic syringomyelia
Sagittal SE T1WI
Sagittal TSE T2WI
Axial SE T1WI
Sagittal TSE T2WI

32. Sagittal TSE T2WI
Sagittal SE T1WI
Sagittal TSE T2WI
Sagittal SE T1WI

33. Enlargement of the central canal
Axial GE T2WI
Axial SET2WI
Sagittal TSE T2WI

34. Progressive posttraumatic myelomalacic myelopathy (PPMM)
0.3–3.2%
2 months ~ 30 years
PPMM is a possible precursor of syringomyelia.
Clinically, PPMM and posttraumatic syringomyelia are neurologically indistinguishable; however, MRI can be used to differentiate the two entities.
PPMM is less well defined than cystic myelopathy and has been reported to return high signal on proton density-weighted images

35. Pathology shows reactive gliosis, microcysts and thickening of the meninges.
It is important to diagnose PPMM since it is potentially treatable.
Local adhesions with cord tethering seem to cause PPMM and surgical untethering with expansive duraplasty leads to clinical improvement in the majority of patients
Intraoperative ultrasound can be helpful in differentiating between myelomalacia and intramedullary cyst formation in this situation

36. PPMM
Sagittal TSE T2WI
Sagittal SE T1WI

37. Sagittal TSE T2WI
Sagittal SE T1WI

38. Spinal cord atrophy
15–20%
Aeduction in the anteroposterior dimensions of the spinal cord from the normal 6 mm at the cervical level to 7 mm at the thoracic level
Usually observed many years after the traumatic event

39. Difficult to differentiate atrophy from a subarachnoid cyst with cord compression
Sometimes, both entities may coexist
The most frequent location of intradural arachnoid cysts is the thoracic thecal sac.
It has been suggested that adhesions secondary to bleeding may impair CSF flow with dilatation of the subarachnoid space and the development of a cyst

40. Spinal cord atrophy
Axialal GE T2WI
Normal size of spinal cord

41. Posttraumatic subarachnoid cyst
Sagittal TSE T2WI
Axial GE T2WI

43. patients who have had spinal surgery for stabilization of vertebral fractures can still be examined by MRI when chronic spinal cord injury is suspected.
Operative implanted materials are now usually MR-compatible and do not significantly interfere with the interpretation of images of the spinal cord

44. operative materials
Sagittal TSE T2WI
Axial GE T2WI

45. Conclusion
Patients with focal neurological signs, evidence of cord or disc injury or whose surgery requires cord assessment should be imaged by MRI.
Moreover, the demonstration of lesions on MRI can be predictive and help to provide a functional prognosis.
In the chronic stage of a spinal cord trauma, MRI is the investigation of choice for evaluating complications and late sequelae in patients who develop new neurological symptoms.
Since some of these lesions are treatable, detecting them is extremely important.