Adolescent Idiopathic Scoliosis

Imaging Studies

The typical radiographic images that are obtained to define scoliosis include a standing X-ray of the entire spine looking both from the back (AP radiograph), as well as from the side (lateral radiograph) (see figure 1). These radiographs are often done with lead shields to protect the patient while allowing for a clear view of the spine. Your physician will be able to measure the radiographs to determine your curves magnitude, which is measured in degrees using the Cobb method (see figure 2). A straight spine has a curve of 0º, any curve greater than 10º is considered scoliosis. Between 0º and 10º is considered a curvature which is not true scoliosis. The way a patient stands at the time of an X-ray or many other factors can cause a slight curvature. The lateral radiograph is used to determine the thoracic kyphosis (or roundback appearance) and the amount of lumbar lordosis (swayback).


Figure 1: Lateral radiograph.	Figure 2: Curves magnitude, measured in degrees using the Cobb method.

Further radiographs can be performed to determine the flexibility of the curvature (how much it straightens). These flexibility radiographs can be done several ways. X-rays can be taken in which the patient lays on the table and bends to the right and then to the left (see figure 3). Traction films are taken with the patient's arms and legs pulled to stretch the spine out. A fulcrum- bend radiograph is taken with a padded roll placed at the apex of the curve to improve the curve correction. These radiographs are most often taken in the planning of surgical treatments.

When bracing treatment is started, radiographs are usually performed with the brace on to ensure that the brace is effective in achieving some correction of the curve(s) (see figure 4). When bracing is use to make a correction X-rays are often used to determine progress. These X-rays can be taken either in the brace or out of the brace depending on the preference of the physician.

A magnetic resonance imaging (MRI) study of the spine is not routinely obtained for patients with AIS. The MRI is specifically used to review other things in addition to the bones of the spine, for instance to view the spinal cord to ensure there are no abnormalities. An MRI is usually ordered if your physician finds some subtle neurologic abnormalities on physical examination, if there is significant pain associated with the scoliosis or if the radiographs demonstrate an "atypical" curve pattern. The likelihood of having something abnormal on the MRI is very small but would require further evaluation with a neurosurgeon if abnormalities are seen.


Figure 3: X-rays can be taken in which the patient lays on the table and bends to the right and then to the left to assess the flexibility of the spine.	Figure 4: Radiographs performed without (left) and with the brace on (right).