<s>[INST] hi i am looking for help to understand a ct scan. L3-4 level is normal. the L4-5 level; there is generalized disc bulging flattening of the underlying ventral thecal sac . There is no exiting nerve root impingement or spinal stenosis . there is vacuum phenomena within the degenerative right-sided facet. The L5-S1 level; there is a generalized disc bulge with associated vacuum phenomena. There is anterior osteophytic change at the L5 S1 level. There is sclerosis of the endplates of the L5 and S1 vertebal bodies. there is no exiting nerve root impingement or spinal stenosis. [/INST] Hi, In simple words you seem to be having a chronic degeneration of the spine which is resulting in disc bulges at the mentioned levels.  It also seems you may have some necrotic changes resulting in gas formation described as vacuum phenomena. This needs to be further evaluated. I am unable to comment further since you haven't provided your clinical details. I would need a detailed medical history with past medical and treatment details to correlate these signs. Wish you good health Regards </s>