question: Hi! I just had an MRI and I haven t seen a doctor to explain to me the impression. Please explain what it means. Please see below. Thank you. Grade 1 spondylolisthesis , L5 over S1 vertebrae Right paracentral disc with posterolateral annular fissure , L4-L5 level with indentation of the ventral thecal sac , narrowing of the right neuroforamina and abutment of the right descending L5 nerve root . Filum terminale lipoma.