Lumbar Spine MRI

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Interpretation

Before doing anything, first verify patient identification and the date of scan

Basic Pulse Sequences for MRI[1]
Image Type TR TE Fat Signal Intensity Water Signal Intensity Advantages Disadvantages
T1 Short Short Bright Dark Best anatomic detail, rapid acquisition Poor visualisation of pathology/oedema
T2 Long Long Intermediate Bright Moderate sensitivity for pathology/oedema Poor spatial resolution, time consuming
Fat-suppressed T2 Long Short Very dark Very bright Most sensitive for pathology/oedema Susceptible to artifacts related to magnetic resonance inhomogeneity
Gradient Echo Short Short Intermediate Intermediate/high Excellent for articular cartilage, PVNS, and blood Very susceptible to metallic artifacts
Proton Density Long Short Intermediate/high Intermediate Excellent for meniscal pathology

Survey View

Count vertebra, and assess for transitional anatomy

Fat Suppressed Coronal

Assess facet joints for effusions, size, cartilage thickness, oedema. Look for extra spinal pathology. Scroll through the sacroiliac joints looking for osteoarthritis, oedema, effusions.

T1 Sagittals

In T1, spinal fluid is dark and fat is bright. Determine the left-right orientation. On the left, the gives off branches at ~L1. On the right, the renal artery runs posterior to IVC. The Aorta is wider than IVC.

Working from caudal to rostral observe:

  • Neural foramina and nerve roots: nerve contact and compression.
  • Intervertebral discs: width, protrusions/ herniations.
  • Spinal column: alignment (spondylolisthesis), vertebral body shape (compression fractures, Schmorls’ nodes), posterior bony elements (spondylolysis), degenerative end plate changes (changes in fat content), hemangiomas.
  • Retroperitoneal space: adenopathy, masses, great vessel aneurysm, etc

T2 Sagittals

In T2, spinal fluid is bright.

Working from caudal to rostral observe:

  • Dural sac—cord and rootlets: width, compression, irregularities
  • Intervertebral discs: width, protrusions/ herniations, hydration, high intensity zones
  • Spinal column: alignment (spondylolisthesis), vertebral body shape (compression fractures, Schmorls’ nodes), posterior bony elements (spondylolysis), degenerative end plate changes (changes in fat content), hemangiomas.
  • Posterior bony elements: breakage, listhesis, pseudo-articulations, etc.

T1 Axials

The CSF appears gray and fat appears bright. Proceed caudal to cranial.

Orientation – neural foramina lie at level of discs.

  • Content of the spinal canal and neural foramina: Trace course of nerve roots through neural foramina
  • Intervertebral discs— continuity, bulges, etc.
  • Bone – Vertebral bodies; spondylolisthesis, posterior bony elements (spondylolysis, breakage)
  • Ligamentam flavum: thickened appearance, impingement
  • Retroperitoneal space: adenopathy, masses, muscle, fat infiltration of multifidus (see image)[2]

T2 Axials

Spinal fluid appears bright. Proceed caudal to cranial.

  • Content of the spinal canal and neural foramina: Trace course of nerve roots through neural foramina
  • Intervertebral discs— continuity, bulges, etc.
  • Bone – Vertebral bodies; spondylolisthesis, posterior bony elements (spondylolysis, breakage)
  • Ligamentam flavum: thickened appearance, impingement
  • Retroperitoneal space: adenopathy, masses, muscle, etc.

Assessment

Ensure you have covered all structures. Assess need for other studies

References

  1. Khanna et al. Magnetic resonance imaging of the knee. Current techniques and spectrum of disease. The Journal of bone and joint surgery. American volume 2001. 83-A Suppl 2 Pt 2:128-41. PMID: 11712834. DOI.
  2. Kjaer et al. Are MRI-defined fat infiltrations in the multifidus muscles associated with low back pain?. BMC medicine 2007. 5:2. PMID: 17254322. DOI. Full Text.

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