Multifocal skeletal tuberculosis involving the lumbar spine and a sacroiliac joint: MR imaging findings.

Sacroiliac joint tuberculosis is rare; its coexistence with vertebral tuberculosis is even rarer, with only a few such patients reported in the literature. We present magnetic resonance (MR) imaging findings of a patient with vertebral and sacroiliac joint tuberculosis, who had paravertebral, iliopsoas, and buttock abscesses accompanied by a gluteal pus-draining sinus tract. MR imaging is the most sensitive and specific imaging modality for diagnosing sacroiliitis at its early stage. Sacroiliac joint tuberculosis can reach advanced stages with extensive joint destruction and periarticular abscesses if diagnosis and treatment are delayed. A high index of clinical suspicion is required for an early diagnosis. The addition of a coronal SPIR T2-weighted sequence to the routine MR imaging evaluation of patients studied for lumbar disk disease may be useful for recognizing sacroiliac joint pathology at an earlier stage.