MRI OF LUMBAR SPONDYLOSIS - A COMPARISON OF SAGITTAL T-2 WEIGHTED AND3 SEQUENCE EXAMINATIONS

The aim of this study was to determine whether a single T-2 weighted s agittal sequence could replace the conventional three sequence examina tion of the lumbar spine. The T-2 weighted sagittal images of 79 lumba r spine MRI examinations were retrospectively reported by three radiol ogists. Features relating to degenerative disease were recorded and an assessment made of whether further sequences were likely to add infor mation. On a separate occasion the T-1 weighted and T-2 weighted sagit tal and T-2 weighted axial sequences were reported blind in relation t o the initial assessment. Areas of disagreement were resolved by conse nsus opinion. The T-2 weighted sequence was compared with the three se quences, taking the three sequence examination as the standard. Disc p rotrusions were diagnosed from the T-2 weighted sagittal images with a sensitivity of 38% and a specificity of 97%. 22 discs reported as a d isc bulge on the T-2 weighted sequence were re-classified as a disc pr otrusion on axial images because of their focal nature. Central canal stenosis was diagnosed on the T-2 weighted sagittal sequence with a se nsitivity of 60% and a specificity of 95%. After assessing the T-2 wei ghted sequence, it was thought unlikely that further sequences would a dd extra information in 60% of cases (48/79). However, further informa tion was obtained in 21% of these cases (10/48) when all the sequences were assessed. The extra information gained by using all three sequen ces was considered to be of greater benefit than the time saved by usi ng a single T-2 sagittal sequence. Other diagnoses where the additiona l sequences proved helpful are discussed.