Used to evaluate pain in the region of the tailbone or low back pain not attributed to disorders of the lumbar spine. MRI can screen for causes of both chronic pain, as well as evaluate for fractures after episodes of trauma. MRI of the sacrum/coccyx is also an effective tool to evaluate for disorders of the sacroiliac (SI) joints, the joints that connect the lower spine to the pelvis. Both inflammatory and degenerative conditions can affect the SI joints and cause pain in the region. MRI can be quite helpful at differentiating between the degenerative and inflammatory conditions affecting the SI joints, helping guide appropriate evaluation and treatment.