appropriate imaging for back pain
TRANSCRIPT
Appropriate imaging for back pain
Dr David Lisle
Brisbane Private Imaging Royal Brisbane Hospital University of Queensland
Appropriate imaging for back pain
• Imaging modalities • Clinical presentations • Guidelines
Appropriate imaging for back pain
• Imaging modalities – Radiographs (X-rays) – Scintigraphy (bone scan) – CT – MRI
• Clinical presentations • Guidelines
Radiographs
What you see
• Bony anatomy and alignment
• Disc height
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
Bone scan
What you see
• Bone pathology – Osteoblastic activity
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
CT
What you see
• Bony anatomy and alignment
• Cross sectional view of spinal canal and foramina
• Disc, thecal sac, nerve roots
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
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
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
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’
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
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
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’
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
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
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
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
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
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
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
Appropriate imaging for back pain
• Imaging modalities • Clinical presentations • Guidelines
– Multiple: different countries and associations
– Common theme: • Triage into 3 broad categories as
described
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*
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
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
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
www.imagingpathways.health.wa.gov.au
National Institute for Clinical Excellence (NICE) UK ACR Appropriateness Criteria
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
• 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)
24/3/2012
24/3/2012 16/12/2011
MRI: pre-vertebroplasty
STIR
2
3
2
3
T1 STIR
• 68M • Sudden onset bilateral leg pain and
weakness • Urinary retention
MRI
• Dx: Cauda equina syndrome • Cause: massive sequestration • Other causes:
– Tumour • Primary of lower cord, nerve, dura, vertebral
body • Secondary
– Trauma
Cauda equina syndrome
30M 60F 70M
T2
• 62 year old male • Severe low back pain of rapid onset • Febrile and unwell • 4 weeks ago underwent abdominal
surgery for perforated diverticulitis
MRI
T2 T1 T1FS con
T2 T1FS con
Thank you