Exam, radiographs. A careful physical may pick it up, but in most cases the deformity is not visible to the eye. Plain radiographs (x-rays) show the slip (spondylolisthesis). If done standing, they can show subtle slips that go away while lying down. Mri and ct are helpful if there are nerve symptoms (like leg pain, numbness, weakness) and if surgery is being considered. Bone scan is sometimes used too.
Xrays. Xrays can make the diagnosis of spondylolisthesis. Xrays can show the relationships of the vertebrae (bones) in your spine and determine if one is slipped relative to the neighboring vertebrae.
Standing xrays. Standing xrays of the lumbar spine in flexion (bending forward) and extension (arching back) are best for evaluating both the misalignment and helping determine instability (does the misalignment move ).