Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

Objective. Signal intensity changes in lumbar pedicles, similar to those de scribed in vertebral body endplates adjacent to degenerated discs, have bee n described as an ancillary sign of spondylolysis on MRI. The purpose: of t his study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease. Design, Eighty-nine lumbar spine MRI examinations without spondylolysis wer e reviewed for marrow signal intensity changes in pedicles and vertebral bo dies as well as for facet degenerative joint disease. Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedic les had adjacent de-generative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001), Eighty-nine percent (41/46) of the pedicles with marrow signal i ntensity changes had adjacent degenerative disc disease. Conclusions. Pedicle marrow signal intensity changes are not a specific sig n of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal inten sity changes are probably a response to abnormal stresses related to abnorm al motion or loading caused by the degenerative changes in the spinal segme nt.