1) The document discusses appropriate imaging for back pain, describing different imaging modalities like X-rays, CT scans, bone scans, and MRI. 2) It categorizes back pain into 3 groups: nonspecific low back pain, back pain associated with radiculopathy, and back pain associated with a specific cause needing prompt evaluation. 3) Guidelines recommend triaging patients into these 3 categories and only imaging those with red flags, severe/progressive neurological symptoms, or if considering surgery/injections. Imaging is not recommended for nonspecific back pain.

1. Appropriate imaging for
back pain
Dr David Lisle
Brisbane Private Imaging
Royal Brisbane Hospital
University of Queensland

2. Appropriate imaging for back pain
• Imaging modalities
• Clinical presentations
• Guidelines

3. Appropriate imaging for back pain
• Imaging modalities
– Radiographs (X-rays)
– Scintigraphy (bone scan)
– CT
– MRI
• Clinical presentations
• Guidelines

4. Radiographs
What you see
• Bony anatomy and
alignment
• Disc height

5. Radiographs
What you see
• Bony anatomy and
alignment
• Disc height
Disadvantages
• Radiation
• Nonspecific
– OA changes in most
adults
• Insensitive
– No direct visualisation
of neural and other
nonbony structures

6. Bone scan
What you see
• Bone pathology
– Osteoblastic activity

7. Bone scan
What you see
• Bone pathology
– Osteoblastic activity
Disadvantages
• Radiation
• Very nonspecific
• Relatively poor
anatomical resolution
– (Improved with
SPECT; SPECT/CT)
– No direct visualisation
of neural and other
nonbony structures

8. CT
What you see
• Bony anatomy and
alignment
• Cross sectional view
of spinal canal and
foramina
• Disc, thecal sac,
nerve roots

9. CT
What you see
• Bony anatomy and
alignment
• Cross sectional view
of spinal canal and
foramina
• Disc, thecal sac,
nerve roots
Disadvantages
• Radiation
• Nonspecific
– Most adults have
‘findings’
• Poor visualisation of
individual neural
structures and disc
anatomy

10. Radiation doses
Imaging test Effective
dose (mSv)
CXRs Background
exposure
Flying hours
CXR 0.02 1 3 days 4
Lumbar X-ray 1.5 75 6/12 300
Lumbar CT 2-10 100-500 8/12 - 3 years 400 - 1800
Bone scan 6 300 2 years 1200

11. MRI
What you see
• Bony anatomy and
alignment
• Bone pathology
• Multiplanar view of
spinal canal and
foramina
• Disc: hydration and
structure
• Neural structures:
cord, nerve roots

12. MRI
What you see
• Bony anatomy and
alignment
• Bone pathology
• Multiplanar view of
spinal canal and
foramina
• Disc: hydration and
structure
• Neural structures:
cord, nerve roots
Disadvantages
• Availability, cost
• Pacemakers,
claustrophobia
• Nonspecific (too
sensitive)
– Most adults have
‘findings’

13. Appropriate imaging for back pain
• Imaging modalities
• Clinical presentations: classification into 3
broad categories
1. Nonspecific low back pain
2. Back pain associated with radiculopathy
3. Back pain associated with a specific
cause requiring prompt evaluation
• Guidelines

14. Back pain categories
1. Nonspecific (mechanical) low back pain
– Acute: < 12 weeks
– Chronic: > 12 weeks
– Ligament/ muscle strain/ tear
– Intervertebral disc degeneration
– Osteoarthritis
– Facet joints
– SI joints
– Spondylolysis/ spondylolisthesis

15. Back pain categories
2. Back pain associated with radiculopathy
a) Unilateral acute nerve root compression
(sciatica)
– Leg pain >> back pain
– Disc herniation
b) Unilateral chronic nerve root compression
– Disc herniation or spinal stenosis
c) Bilateral chronic nerve root compression
– Spinal stenosis
– DD vascular claudication
d) Bilateral acute nerve root compression =
‘cauda equina syndrome’

16. Cauda equina syndrome
• Bilateral acute nerve root compression
– Massive disc protrusion/ sequestration
• Sudden onset bilateral leg pain
• Saddle anaesthesia
• Rapidly progressive or severe neurological
deficits
– Motor deficits at >1 level
– Faecal incontinence
– Urinary retention

17. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Cauda equina syndrome
− Cancer
− Vertebral infection
− Vertebral compression fracture
− Ankylosing spondylitis

18. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Cauda equina syndrome
− Clinical scenario
− Cancer
− Vertebral infection
− Vertebral compression fracture
− Ankylosing spondylitis

19. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Cancer
− Hx of Ca + new onset LBP
− Unexplained weight loss +/-
persistent symptoms +/- age > 50
− Vertebral infection
− Vertebral compression fracture
− Ankylosing spondylitis

20. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Vertebral infection
− Fever
− iv drug use
− Recent infection
− Vertebral compression fracture
− Ankylosing spondylitis

21. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Vertebral compression fracture
− Hx of osteoporosis
− Steroid use
− Old age +/- minor trauma
− Ankylosing spondylitis

22. Back pain categories
3. Back pain associated with a specific
cause requiring prompt evaluation
− Ankylosing spondylitis (seronegative
SpA)
− Nonmechanical, inflammatory type of
back pain: morning stiffness; improved
with exercise
− Alternating buttock pain
− Waking at night
− Younger age

23. Appropriate imaging for back pain
• Imaging modalities
• Clinical presentations
• Guidelines
– Multiple: different countries and
associations
– Common theme:
• Triage into 3 broad categories as
described

24. LOW BACK PAIN GUIDELINES
Diagnostic triage
1. Non-specific LBP
2. Radiculopathy
3. Specific LBP
• ‘Red flags’
‘Red Flags’
• Cauda equina syndrome
• Known 10 tumour
• Weight loss
• Severe symptoms, not
settling
• Fever
• Recent infection or Sx
• Osteoporosis
• Steroid use
• Non-mechanical pain
• Child*

25. Back pain in children and adolescents
Presentation Associated Sx DD Ix
Night pain Fever, malaise Tumour, infection X-ray
MRI
Acute pain Radiculopathy
+ve SLR
Disc herniation
Spondylosis
X-ray
MRI
Chronic pain Rigid kyphosis
Morning stiffness
“Scheuermann’s”
Inflammatory arthropathy
X-ray
Pain with extension
Sport: eg rowing
Hamstring tightness Spondylolysis
‘Stress reaction’
X-ray
MRI
Pain + recent onset
scoliosis
Fever, malaise,
+ve SLR
Idiopathic scoliosis
Tumour, infection, syrinx,
disc herniation
X-ray
MRI
Am Fam Phys 2007;76:1669-76

26. LOW BACK PAIN GUIDELINES
• American College of Physicians & American
Pain Society Recommendations
1. Focused Hx and examination to place patients
into 1 of 3 categories
2. No imaging for nonspecific LBP
3. Imaging for LBP + severe or progressive
neurological deficits OR risk factors for specific
cause
4. Imaging for LBP and radiculopathy if candidates
for surgery or epidural injection
Ann Intern Med 2007;147:478-491

27. Diagnostic work-up
Possible cause Imaging Additional studies
Nonspecific LBP None None
Radiculopathy MRI (CT)
Cauda equina MRI
Cancer MRI for known 10; X-ray
for other eg wt loss
ESR
Vertebral infection MRI ESR, CRP
Vertebral compression # X-ray
Ankylosing spondylitis X-ray, incl pelvis (MRI) HLA-B27; ESR, CRP
Ann Intern Med 2007;147:478-491

28. www.imagingpathways.health.wa.gov.au
National Institute for Clinical Excellence
(NICE) UK
ACR Appropriateness Criteria

29. Ineffectiveness of imaging for
nonspecific LBP
• Favourable natural Hx
– Most improve by 4 weeks; unaffected by imaging
• Nonspecificity: loose association between findings
and symptoms
– ‘Abnormalities’ or normal aging?
• Potential harms:
– Radiation
– ‘Labelling’
– Incidental findings
Ann Intern Med 2011;154:181-190

31. • 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
Radiograph (X-ray)

33. 24/3/2012

34. 24/3/2012 16/12/2011

35. MRI: pre-vertebroplasty
STIR

36. 2
3
2
3
T1 STIR

38. • 68M
• Sudden onset bilateral leg pain and
weakness
• Urinary retention
MRI

41. • Dx: Cauda equina syndrome
• Cause: massive sequestration
• Other causes:
– Tumour
• Primary of lower cord, nerve, dura, vertebral
body
• Secondary
– Trauma

42. Cauda equina syndrome
30M 60F 70M
T2

44. • 62 year old male
• Severe low back pain of rapid onset
• Febrile and unwell
• 4 weeks ago underwent abdominal
surgery for perforated diverticulitis
MRI

45. T2 T1 T1FS con

46. T2 T1FS con

47. Thank you