SPECT and lumbar MRI in back pain with emphasis on changes in end plates in association with disc degeneration.

Over a two-year period, 48 sequential patients were selected because they showed type I or II end plate changes on magnetic resonance imaging (MRI) and/or had positive single-photon emission computerized tomography (SPECT) scan in the area of disc degeneration. They were selected out of a large group of patients who were being evaluated by MRI and SPECT scan for low back pain. In this group of 48 patients, 47 had positive SPECT scans at the disc space, which on MRI indicates degenerative disc disease. Of these, 38 had end plate changes on the MRI, but 10 did not have end plate changes on the MRI even though their SPECT was positive. None of the 48 patients had evidence of other pathology such as fracture, metastatic disease or spondylolysis. The MRI changes were both of type I and type II and thought to represent increased vascularization of the fibrous tissue or fatty replacement of marrow in the area of the end plate. Based on this study, we are proposing that a positive end plate SPECT in degenerative disc disease is related to marrow changes in the region of the end plate of the disc. Also, we are proposing that SPECT may be of value in delineating early end plate changes prior to the MRI showing type I or type II change in the same area.