Scoliosis is usually diagnosed by physical examination, X-ray, spinal radiography, CT scan or MRI. The success of treatment depends on age and how severe the curvature is. In infants and young children, the curvature of the spine may improve over time, so treatment may not be necessary. When children grow older, back corsets or plastic support can be worn to prevent the curvature from worsening. In curvatures whose progression cannot be stopped with a corset, surgery is recommended if the curvature is over 40 degrees. The age of the child, the degree of maturation of the skeletal system and the need to prevent complications that may develop are the factors taken into consideration when deciding on surgery.