Книги по МРТ КТ на английском языке / MRI for Orthopaedic Surgeons Khanna ed 2010
.pdf282 IV Spine
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Fig. 11.17 Modic type 3 (sclerotic) changes. Sagittal T1-weighted |
level that is seen with Modic type 3 end-plate changes. Note that |
(A) and fat-suppressed T2-weighted (B) images showing the typical |
degenerative changes are seen at other levels and that there is also |
pattern (arrow[s] on each) of decreased signal intensity at the L2-L3 |
evidence of lumbar scoliosis. |
Annular Tears |
(Fig. 11.8). The high-intensity zone is defined as a focal area |
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Annular tears on MRI have a variable appearance, ranging |
of high signal intensity within the posterior annulus of the |
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degenerating disc, separate from the nucleus. These high- |
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from intermediate to high signal intensity on T2-weighted |
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intensity zones may also enhance after intravenous gado- |
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images. Studies have shown a correlation between high |
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linium administration.33 |
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signal intensity annular tears in the lumbar spine and |
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Discography can be used to further evaluate patients |
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painful concordant annular tears seen at provocative |
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with annular tears. In addition to the morphologic in- |
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discography.37,38 Some investigators have suggested that |
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formation provided on fluoroscopic images and on post- |
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the inflammation associated with these annular tears |
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discography CT, the patient’s pain response can be used |
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results in irritation of the adjacent nerve root, poten- |
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to help predict whether an annular tear or other degen- |
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tially leading to radiculopathy without overt mechanical |
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erative pathology is the patient’s pain generator.39,40 It is |
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nerve root compression.38 T2-weighted sequences have |
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important to keep in mind, however, that the use of dis- |
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been used to show the following three types of annular |
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cography in the diagnosis of discogenic low back pain con- |
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tears: |
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tinues to be debated and is not uniformly accepted at all |
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• Concentric |
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centers. |
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• Radial |
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• Transverse |
Lumbar Herniated Nucleus Pulposus |
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Concentric tears involve the entire extent of the annulus. |
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The terms used to describe the progressive states of herni- |
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Transverse tears occur at the periphery of the disc as a result |
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of disruption of Sharpey’s fibers. Radial tears extend from |
ated nucleus pulposus have been addressed above (see No- |
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the nucleus through the annulus and may extend into the |
menclature and Classification of Lumbar Disc Pathology). |
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outer annulus, manifested on MRI as a high-intensity zone |
Shown here are the MRI appearances of each: |