Presented by: Dr David Lisle — Radiologist Event: Mackay GP & Allied Health Education Day - 2014

1. Image interpretation: spine
Dr David Lisle
Brisbane Private Imaging

2. Image interpretation
• Anatomy
• Cross sectional techniques:
– CT
– MRI
• Nomenclature of disc herniations and spinal
stenosis
• A few cases

3. Image interpretation
• Anatomy
• Cross sectional techniques:
– CT
– MRI
• Nomenclature of disc herniations and spinal
stenosis
• A few cases

5. Image interpretation
• Anatomy
• Cross sectional techniques:
– CT
– MRI
• Nomenclature of disc herniations and spinal
stenosis
• A few cases

6. Development of CT
• 70’s
• Each slice 60secs
• 20-30 mins/ head scan

7. • 70’s – 80’s
• 5-10 secs/ slice
• 5 mins/ head scan
• Longer for body and spine: up to 20 mins

8. 1974 1988

9. Spiral (helical) CT
• 90’s
• Speed
– Patient acceptance
– Different phases of contrast
enhancement
• Volumetric data set
– Multiplanar and 3D
reconstructions

10. Multidetector (multislice) CT
• Late 90’s to present
• 0.175 - few seconds scan
time
• Overlapping =
reconstructions
• Contiguous = speed
• Original: 4 slice
• 2nd generation: 16, 64
• New: 256; 320

11. Workstation reporting

15. MRI: T1
– Fat bright
• Bone marrow
– Bone cortex black
– Anatomy

16. MRI: T2
– Bone cortex black
– Anatomy
– Fluid bright
– Fat bright
• Bone marrow
– Oedema bright
• Difficult to
differentiate

17. MRI: STIR or T2FS
– Fat ‘saturated out’
• Bone marrow black
– Fluid bright
– Differentiate oedema
from marrow

18. T1 T2 STIR

19. MRI: T1FS-Gd
– Fat ‘saturated out’
• Bone marrow and other
fat black
– Non-fat T1 bright
• Haemorrhage
• Movement
• Enhancement
Ø Pathology
Ø Veins
Ø Nerve root ganglia

21. T1

23. T1

25. Image interpretation
• Anatomy
• Cross sectional techniques:
– CT
– MRI
• Nomenclature of disc herniations and spinal
stenosis
• A few cases

26. NOMENCLATURE
• Consistent
• Reflect common usage where appropriate
• Surgically relevant
• ‘Able to visualize over the phone’
• 2 morphological characteristics:
– Nature of disc pathology
– Location
• Able to add further descriptors
– Neural structures
– Clinical context
• www.asnr.org/spine_nomenclature/reporting

27. Disc bulge
• Generalised extension of disc tissue beyond
intervertebral disc space
• ‘Generalised’ = >50% circumference (>1800)
• Relatively short distance, <3mm

29. Herniated disc
• Localised displacement of disc material beyond
intervertebral disc space (ie bony margins excluding
osteophytes) OR break in vertebral end plate (Schmorl’s
node)
• ‘Localised’ = <50% circumference (<1800)
– ‘Broad based’ = 25 - 50% circumference (>900)
– ‘Focal’ = <25% circumference (<900)
• ‘HNP’ not accurate
– Herniation may include NP, cartilage, annulus, bone
• ‘Rupture’ tends to refer to trauma/ acute event
• ‘Prolapse’ and ‘bulging disc’ outdated
• ‘Localised disc bulge’ = oxymoron

31. Extruded disc
• Greatest distance in any plane
between edges > base
T1

32. Sequestered disc
• Extruded disc material that has no continuity with
the disc of origin
• = free fragment
• Migrated disc:
– Disc material displaced away from site of extrusion

33. T2 T2
T1

34. Location of herniation
• Anatomic system that correlates with surgery
• Landmarks, transverse plane:
– Sagittal and coronal planes at centre of disc
– Medial edge of articular facet
– Medial, lateral borders of pedicles

35. Location of herniation
• Locations, transverse plane:
– ‘Central’ = midline
– ‘Right central’ & ‘left central’ =
paracentral/ posterolateral
– ‘Subarticular’ = lateral recess
– ‘Foraminal’
– ‘Extraforaminal’ = far lateral

36. Location of herniation
• Locations, transverse plane:
– ‘Central’ = midline
– ‘Right central’ & ‘left central’ =
paracentral/ posterolateral
– ‘Subarticular’ = lateral recess
– ‘Foraminal’
– ‘Extraforaminal’ = far lateral

37. Location of herniation
• Locations, transverse plane:
– ‘Central’ = midline
– ‘Right central’ & ‘left central’ =
paracentral/ posterolateral
– ‘Subarticular’ = lateral recess
– ‘Foraminal’
– ‘Extraforaminal’ = far lateral

38. Location of herniation
• Locations, transverse plane:
– ‘Central’ = midline
– ‘Right central’ & ‘left central’ =
paracentral/ posterolateral
– ‘Subarticular’ = lateral recess
– ‘Foraminal’
– ‘Extraforaminal’ = far lateral

39. Location of herniation
• Locations, transverse plane:
– ‘Central’ = midline
– ‘Right central’ & ‘left central’ =
paracentral/ posterolateral
– ‘Subarticular’ = lateral recess
– ‘Foraminal’
– ‘Extraforaminal’ = far lateral

40. Volume: degree of canal
compromise
• X-sectional area at site of maximal narrowing
• ‘Mild’: <1/3
• ‘Moderate’: 1/3 – 2/3
• ‘Severe’: > 2/3
• Same grading for foraminal narrowing as seen in
sagittal plane
• Other descriptors such as compression of
specific neural structures

41. Mild Moderate Severe

42. Image interpretation
• Anatomy
• Cross sectional techniques:
– CT
– MRI
• Nomenclature of disc herniations and spinal
stenosis
• A few cases

43. • 85 year old female
• Severe acute on chronic mechanical back pain
– Can’t sleep
– Limited walking to only a few steps
• Spontaneous onset
• No known trauma

44. What is the most likely diagnosis?
1. Acute disc herniation
2. Facet joint degeneration
3. Crush fracture secondary to osteoporosis
4. Metastatic cancer

45. What is the most appropriate
imaging modality?
1. Plain film
2. CT
3. Scintigraphy (bone scan)
4. MRI

47. 24/3/2012

48. 24/3/2012 16/12/2011

50. MRI: pre-vertebroplasty
STIR

51. 2
3
2
3
T1 STIR

53. • 68M
• Sudden onset bilateral leg pain and weakness
• Urinary retention

54. What is the most likely diagnosis?
1. Guillain Barre syndrome
2. Cauda equina syndrome
3. Crush fracture secondary to osteoporosis
4. Discitis/ osteomyelitis

55. What is the most appropriate
imaging modality?
1. Plain film
2. CT
3. Scintigraphy (bone scan)
4. MRI

58. • Dx: Cauda equina syndrome
• Cause: massive sequestration
• Other causes:
– Tumour
• Primary of lower cord: ependymoma
• Primary of nerve: BPNST
• Primary of dura: meningioma
• Primary of vertebral body: chordoma, giant cell
tumour
• Secondary
– Trauma