PURPOSE: To evaluate the usefulness of 3DFT CISS MR myelography (MRM) by comparing it with 3DFT FISP MRM. MATERIALS AND METHODS: Thirty-four subjects consisting of normal volunteers and patients complaining of back pain underwent lumbar spine MRI, 3DFT CISS MRM, and 3DFT FISP MRM. The 3DFT FISP MRM and 3DFT CISS MRM images were analysed and in each case, the following were compared : sharpness of the dural sac; differentiation of nerve roots and CSF ; visualization of the nerve root sleeve and of dural sac compression. RESULTS: Image acquisition time of 3DFT CISS MRM was shorter than that of 3DFT FISP MRM, and the former was significantly superior to the latter in sharpness of the dural sac (86%, p=0.004), differentiation of nerve roots and CSF (74%, p=0.0168), andvisualization of dural sac compression (90%, p=0.0016). With regard to visualization of nerve root sleeves, 3DFT CISS MRM was superior to 3DFT FISP MRM, but not significantly (68%, p=0.0872). CONCLUSION: 3DFT CISS MRM requiresa shorter image acquisition time and gives a better image than 3DFT FISP MRM; we therefore consider it to be a useful MR method.