Magnetic resonance imaging (MRI) of the lumbar spine with dedicated G-scan machine in the upright position: a retrospective study and our experience in 10 years with 4305 patients.

PURPOSE: To evaluate the pathological changes of the lumbar spine and the instability of the lumbar intervertebral joints observed in patients with low back pain, with the study of the transition from supine to orthostatic position through the use of dedicated MRI-G-scan machine. MATERIALS AND METHODS: Within 10 years, 4305 patients, aged between 21 and 80 years old, with history of low back pain with or without sciatica, underwent MRI examinations in upright and in supine position. The open MRI-scanner used is Esaote G-scan, which enables the acquisition of images in supine and standing positions. The used sequences were sagittal T2-weighted FSE, T1-weighted SE and axial 3D HYCE. Patients were divided into two groups: "negatives", with no changes in the two positions (supine and upright), and "positives", with MRI modifications of imaging in upright position. RESULTS: Orthostatic examination showed MRI changes in 2870 out of 4305 (66.6%) patients, including 1252 males and 1618 females. CONCLUSIONS: The G-scan is useful to assess instability of the lumbar spine detecting hidden modifications of protrusions and/or herniated discs already present in the supine position. It is also helpful in assessing the presence or modification of spondylolisthesis and lumbar canal stenosis.