Appropriate imaging for back pain

Appropriate imaging for back pain

Dr David Lisle

Brisbane Private ImagingRoyal Brisbane HospitalUniversity of Queensland


• Imaging modalities• Clinical presentations• Guidelines• Children


• Imaging modalities– Radiographs (X-rays)– Scintigraphy (bone scan)– CT– MRI

• Clinical presentations• Guidelines• Children

Radiographs

What you see

• Bony anatomy and alignment

• Disc height

Radiographs

What you see


• 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


• Cross sectional view of spinal canal and foramina

• Disc, thecal sac, nerve roots

CT

What you see


• 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

MRIWhat you see


• Bone pathology• Multiplanar view of

spinal canal and foramina

• Disc: hydration and structure

• Neural structures: cord, nerve roots

MRIWhat you see


• 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’


• Imaging modalities• Clinical presentations: classification into 3

broad categories1. Nonspecific low back pain2. Back pain associated with radiculopathy3. Back pain associated with a specific

cause requiring prompt evaluation• Guidelines• Children

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


2. Back pain associated with radiculopathya) 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


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


3. Back pain associated with a specific cause requiring prompt evaluation− Cauda equina syndrome− Clinical scenario

− Cancer− Vertebral infection− Vertebral compression fracture− Ankylosing spondylitis


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


3. Back pain associated with a specific cause requiring prompt evaluation− Vertebral infection− Fever− iv drug use− Recent infection

− Vertebral compression fracture− Ankylosing spondylitis


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


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


• Imaging modalities• Clinical presentations• Guidelines

– Multiple: different countries and associations

– Common theme:• Triage into 3 broad categories as

described• Children

LOW BACK PAIN GUIDELINESDiagnostic triage

1.Non-specific LBP2.Radiculopathy3.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*

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 LBP3. 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 studiesNonspecific LBP None NoneRadiculopathy MRI (CT)Cauda equina MRICancer MRI for known 10; X-ray

for other eg wt lossESR

Vertebral infection MRI ESR, CRPVertebral compression # X-rayAnkylosing 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) UKACR 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



Back pain in children and adolescents

Presentation Associated Sx DD Ix

Night pain Fever, malaise Tumour, infection X-rayMRI

Acute pain Radiculopathy+ve SLR

Disc herniationSpondylosis

X-rayMRI

Chronic pain Rigid kyphosisMorning stiffness

“Scheuermann’s”Inflammatory arthropathy

X-ray

Pain with extensionSport: eg rowing

Hamstring tightness Spondylolysis‘Stress reaction’

X-rayMRI

Pain + recent onset scoliosis

Fever, malaise, +ve SLR

Idiopathic scoliosisTumour, infection, syrinx, disc herniation

X-rayMRI

Am Fam Phys 2007;76:1669-76

MRI: paediatric items

• Referral by a medical practitioner– (Excluding specialist or consultant

physician)• Age under 16• Issues re GA/ sedation• Practical terms: 5/6 to 15

– Younger for a ‘good’ kid– Older for a ‘not so good’ kid


• Head• Spine, following radiographic examination• Knee following radiographic examination

for internal derangement• Hip following radiographic examination• Elbow following radiographic examination• Wrist following radiographic examination


• Head

• Spine, following radiographic examination– Significant trauma– Neck or back pain + neurological signs– Back pain, significant pathology suspected

• Knee following radiographic examination for internal derangement

• Hip following radiographic examination• Elbow following radiographic examination• Wrist following radiographic examination

9M

Spine trauma

Neck pain + neurology

9F

Back pain, gymnast

11F

STIR T1



Thank you

Appropriate imaging for back pain

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