Figure 1. a–e.

MRI and ^99mTc-MDP SPECT/CT images of a 67-year-old woman taken 10 days apart. The right L4/L5 and L5/S1 facet joints were rated as normal by consensus on MRI but as having increased activity on ^99mTc-MDP SPECT/CT. Sagittal short tau inversion recovery images (a, b) focused on the right L4/L5 (a) and L5/S1 (b) facet joints demonstrate no substantial peri-facet signal change. There is minimal fluid signal within the inferior recesses of the facet joints (arrows), which is not considered sufficient for designation of peri-facet signal change and is not factored in the grading scale. Coronal (c) and right sagittal (d) ^99mTc-MDP SPECT/CT images of the lumbar spine demonstrate increased activity around the right L4/L5 and L5/S1 facet joints relative to adjacent facet joints in the lumbar spine. Axial ^99mTc-MDP SPECT/CT at the L4/L5 level (e) demonstrates increased activity of the right facet joint.