LOW-FIELD MR-IMAGING OF THE SPINE - A COMPARATIVE-STUDY OF A TRADITIONAL AND A NEW, COMPLETELY BALANCED GRADIENT-ECHO SEQUENCE

Purpose: To evaluate a new steady-state sequence in the delineation of the various structures in the spine at low-field MR imaging with a ve ry high homogeneity of the main field. Methods: 49 patients underwent 53 examinations with both a traditional T1-weighted gradient-echo (PS) sequence and a new completely balanced steady-state 3-D (CBASS3D) seq uence; 20 examinations included the cervical spine, 8 the thoracic spi ne and 25 the lumbar spine. All 106 examinations were reviewed twice r egarding visibility of selected structures in the spinal region and di agnostic usefulness. Results: The CBASS3D sequence delineated the medu lla, nerve roots, CSF, the intervertebral discs and the posterior long itudinal ligament significantly better than the PS sequence. Disc hern ia was also better visualised (p<0.01). There were significantly more artefacts on images obtained with the CBASS3D sequence, but they were usually outside the region of interest and occurred less frequently ov er time due to increased experience of the staff. Both reviewers found the diagnostic usefulness of CBASS3D to be superior compared to that of PS and excellent for diagnostic purposes. Conclusion. The CBASS3D s equence is a considerable improvement in the visualisation of degenera tive changes of the spine at low-field MR imaging.