MR whole-spine recording: computer-assisted simulation of the conventional x-ray technic

Abstract

Development of an MR-based imaging technique for the spine allowing reduction of frequency of conventional Nadiographs in the monitoring of juvenile scoliosis. 25 patients between the ages of 6 to 36 years were examined in supine position. Two examinations of the cervical and upper thoracic spine and of the lower thoracic and lumbar spine were performed with a 1.5 T Gyroscan ACS-NT Powertrak 6000 system with body coil employing 3D EPI-sequence (TR 17 ms, TE 9 ms, flip angle 20 degrees, field of view 450 mm) or 3D FFE sequences (TR 9 ms, TE 4.5 ms, flip angle 20 degrees, field of view 450 mm) and pulse-oximetry gating. 64 coronal slices were acquired with reconstructed slice thickness of 2 mm. Image processing was performed with an algorithm merging acquisition results into two single images in the coronal and sagittal orientations allowing measurement of the Cobb angle. Mean examination time was 14 minutes per patient. Mean data processing time was seven minutes. Interobserver variance of determination of the Cobb angle was 1.8 degrees. It is to be hoped that MR whole spine projection will allow a reduction of the frequency of conventional projection in the monitoring of juvenile scoliosis.