78-year-old female with left buttock pain. Abnormal sacroiliac joint and left hip MRI. Evaluate left sacroiliac joint. There is increased signal abnormality within an enlarged left piriformis and left iliacus muscle as well as within the left paraspinal musculature. There is increased signal abnormality about and within the left sacroiliac joint which demonstrates enhancement on post contrast sequences consistent with sacroiliitis. No definite erosions are identified. There is heterogenous bone marrow signal abnormality which is nonspecific but likely represents residual islands of red marrow. Although this examination was not protocoled for detailed evaluation of the lumbar spine, there is an apparent disc bulge at the level of L4/L5 with associated central spinal canal stenosis. This could be further evaluated with a dedicated lumbar spine MRI if clinically warrented.
1. Findings suggestive of left sided sacroiliitis as described above. Nonspecific increased signal abnormality within the left iliacus muscle and left paraspinal musculature may also be related to the aforementioned sacroiliitis.2. Increased signal abnormality within an enlarged left piriformis muscle with inflammatory changes in the surrounding area, particularly about the left sciatic nerve, which is nonspecific and may be related to the aforementioned sacroiliitis, however, this can be seen in patient's with piriformis syndrome.3. Apparent diffuse disc bulge at the level of L4/L5 with associated central spinal canal stenosis. This is incompletely visualized and could be further evaluated with a dedicated lumbar spine MRI if clinically indicated. 