Image the WHOLE spine, find every level, and state the highest level with cord signal change — the clinical level is often wrong.
Orient first
- Cord compression is a time-critical diagnosis: the neurological state at the moment of treatment is the strongest predictor of the outcome, so speed of reporting matters as much as accuracy.
- Metastatic disease is frequently at MULTIPLE levels, and a second lesion above the clinical level changes the radiotherapy field or the surgical plan. This is why the whole spine is imaged, not the symptomatic region.
- The clinically-determined sensory level is unreliable and is often several segments away from the true compressive level.
- Below the conus the problem is cauda equina compression, not cord compression, and the anatomy and urgency wording differ.
Acquire the study
- MRI WHOLE SPINE — cervical, thoracic and lumbosacral — sagittal T1 and sagittal T2 or STIR as the minimum. STIR is the sequence in which marrow disease shouts.
- AXIAL sequences through every abnormal level; the degree of canal and cord compromise cannot be judged on sagittals alone.
- Contrast is not required to make the diagnosis but helps with intradural or leptomeningeal disease.
- If MRI is contraindicated, say so and recommend CT myelography rather than reporting a CT as equivalent.
The manoeuvre
- Scroll the whole sagittal T1 for marrow replacement — metastases are LOW signal against normally fatty adult marrow, and T1 is the most reliable screening sequence.
- Compare with STIR, where disease is high signal.
- At every abnormal level, assess epidural soft tissue, the degree of thecal sac indentation, and whether the cord is deformed or merely abutted.
- Look for CORD SIGNAL CHANGE (high T2 within the cord) — this indicates myelopathy and carries prognostic weight.
- State the HIGHEST level of compression and list every other involved level.
- Assess vertebral body height loss, posterior wall retropulsion and pedicle involvement — these drive stability assessment.
- Distinguish benign osteoporotic collapse from malignant: benign tends to spare the pedicles, show a fluid sign and a retropulsed fragment with preserved marrow; malignant shows complete marrow replacement, a convex posterior wall, pedicle involvement and an epidural soft-tissue mass.
- Look at the conus level to decide cord versus cauda equina.
What confirms it
- Epidural tumour indenting the thecal sac with cord deformity is cord compression.
- Cord signal change indicates established myelopathy and should be stated explicitly.
What licenses you to exclude it
- A whole-spine MRI with normal marrow, no epidural disease and a normal cord excludes metastatic cord compression.
- ⚠️ A study limited to the symptomatic region does not exclude disease elsewhere, and must say so rather than being reported as a normal spine.
The classic misread
- Imaging only the clinically suspected region.
- Missing a second, higher level of compression.
- Not stating whether there is cord signal change.
- Calling a benign osteoporotic fracture malignant, or the reverse — check the pedicles and the marrow.