Doctors use back x-rays to examine the vertebrae in the spine for fractures, arthritis, or spine deformities such as scoliosis, as well as for signs of infection or cancer. X-rays can be taken separately for the three areas of the spine: the cervical spine (neck), thoracic spine (middle back), and lumbar spine (lower back). Occasionally, doctors x-ray the pelvis to help diagnose the cause of back pain.