Lumbar Spine MRI: Difference between revisions
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==Interpretation== | ==Sagittal MRI Sequences== | ||
Sagittal MRI scans are typically taken across five standard planes. There may be further scans between these planes, or it may be slightly displaced to the left or right. | |||
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|+ Sagittal MRI five standard planes and the intersecting structures | |||
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! Plane !! Extra-vertebral canal structures !! Vertebral canal structures | |||
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| style="width: 10%" |Median || style="width: 45%" | Vertebral bodies and intervertebral discs (AP and AF) anteriorly, and the spinous processes posteriorly || Conus medullaris at upper segmental levels, and the cauda equina at lower levels. | |||
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| Paramedian || Vertebral bodies and intervertebral discs anteriorly (AP and AF), and the laminae posteriorly || May miss the spinal cord, and only show the cauda equina. | |||
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| Transpedicular || Lateral sectors of the vertebral bodies, the lateral sectors of the intervertebral discs (AF +/- NP), the pedicles, and some portions of the facet joints. Slightly more medial intersects the inferiorly articular processes. Slightly more lateral intersects the superior articular processes || Spinal nerves and their dural sleeves as they pass under the pedicles | |||
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| Tangential || Most lateral margins of the vertebral bodies and the AF at each segmental level, or the concavity of the vertebral body || No intersection | |||
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| Peripheral || Transverse processes || No intersection | |||
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==Check List for Interpretation== | |||
Before doing anything, first verify patient identification and the date of scan | Before doing anything, first verify patient identification and the date of scan | ||
Revision as of 17:38, 6 May 2021
Sagittal MRI Sequences
Sagittal MRI scans are typically taken across five standard planes. There may be further scans between these planes, or it may be slightly displaced to the left or right.
Plane | Extra-vertebral canal structures | Vertebral canal structures |
---|---|---|
Median | Vertebral bodies and intervertebral discs (AP and AF) anteriorly, and the spinous processes posteriorly | Conus medullaris at upper segmental levels, and the cauda equina at lower levels. |
Paramedian | Vertebral bodies and intervertebral discs anteriorly (AP and AF), and the laminae posteriorly | May miss the spinal cord, and only show the cauda equina. |
Transpedicular | Lateral sectors of the vertebral bodies, the lateral sectors of the intervertebral discs (AF +/- NP), the pedicles, and some portions of the facet joints. Slightly more medial intersects the inferiorly articular processes. Slightly more lateral intersects the superior articular processes | Spinal nerves and their dural sleeves as they pass under the pedicles |
Tangential | Most lateral margins of the vertebral bodies and the AF at each segmental level, or the concavity of the vertebral body | No intersection |
Peripheral | Transverse processes | No intersection |
Check List for 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, Schmorlsโ 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 sacโcord and rootlets: width, compression, irregularities
- Intervertebral discs: width, protrusions/ herniations, hydration, high intensity zones
- Spinal column: alignment (spondylolisthesis), vertebral body shape (compression fractures, Schmorlsโ 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 โ neural foramina lie at level of discs.
- Content of the spinal canal and neural foramina: Trace course of nerve roots through neural foramina
- Intervertebral discsโ continuity, bulges, etc.
- Bone โ 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 discsโ continuity, bulges, etc.
- Bone โ 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
- โ 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.
- โ 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.
Literature Review
- Reviews from the last 7 years: review articles, free review articles, systematic reviews, meta-analyses, NCBI Bookshelf
- Articles from all years: PubMed search, Google Scholar search.
- TRIP Database: clinical publications about evidence-based medicine.
- Other Wikis: Radiopaedia, Wikipedia Search, Wikipedia I Feel Lucky, Orthobullets,