Hello,
Thank you for asking the query:
There is a posterior disc bulge in the L5-S1 level. I cannot comment on the L4-L5 disc bulge or the thecal sac effacement as the image set appears to be incomplete. (also no DICOM images) From the sagittal sections available there is also possible disc bulge in L4-L5 levels too.
The radiological diagnosis need to be correlated with your clinical finding too. So I would like to know whether you are having any signs or symptoms like low back pain, pain in buttocks or legs? It is not prudent to base of diagnosis based on the MRI finding alone.
Thank you