Scoliosis rates in symptomatic patients as demonstrated with weight-bearing or supine MR imaging.

CONTEXT In the United States an estimated 6 million persons are affected by scoliosis, which is characterized by a 3-dimensional deformity of the spine that involves a curvature in the sagittal, frontal, and transverse planes. OBJECTIVE To determine the rates of scoliosis in patients with spine-related pain unassociated with cancer, as demonstrated by magnetic resonance (MR) images obtained with patients in either a weight-bearing or a supine position. METHODS The authors conducted a retrospective review of MR images obtained during a 2-year period in patients referred because of symptoms of radiculopathy or other spine-related pain unassociated with cancer and unresolved after conservative treatment. Images were obtained either with the patient supine or with the patient in a weight-bearing, seated position, and all images were reviewed by a neuroimaging physician. Scoliosis was assessed according to the Cobb angle method. RESULTS A total of 1982 MR images from 1486 patients were reviewed. Of those, 986 images in 761 patients were obtained with a low-field-strength (0.3-T) MR imager with the patient supine, and 996 images in 725 patients were obtained with a mid-field-strength (0.6-T) MR imager with the patient in a weight-bearing, seated position. Scoliosis (dextroscoliosis, levoscoliosis, or both) was identified in 958 MR images (48.3%), of which 779 (78.2%) were obtained with patients in a weight-bearing position and 179 (18.2%) were obtained with patients in a supine position. CONCLUSION The scoliosis rate was lower in the supine MR imaging group than in the weight-bearing MR imaging group. Scoliosis rates may be affected by the position in which the patient is examined, with the possibility that the weight-bearing position differentially exposes scoliosis, compared with the supine position.