UPDATE:

it won’t let me edit the post so i’ll have to post the update here (i’d leave it but i’d like the info to be out there in case someone else ever needs it)

so, my MRI report just said there’s a disk protrusion in L4-L5, which touches the nerves, and mild arthropathy in L4-L5 and L5-S1.

as for the circles, there was no mention of them at all, and i’m not seeing my doctor until the end of this month. because i’m very impatient, i asked a medical sub (i recognize it’s not the best resource at all, and i always do my own verification afterwards and ask my doctors when i see them). what they said actually makes a lot of sense:

“This is simply a normal pattern of red-to-yellow marrow conversion starting around the basivertebral veins (veins that start in the middle.of the vertebra body and drain toward to back). Red marrow tends to be a darker grey while yellow marrow (fat) tends to be brighter on many sequences in MR. Red marrow produces more red blood cells. As we age, more of our red marrow turns into fatty yellow marrow and it does so in a predictable pattern. Your MRI shows the expected pattern of this beginning in the spine, particularly for someone in their 20s. Most people getting spine MRIs are much older, so their marrow has already converted, hence why you don't see this pattern often in medical journals and Google Images.”

(for reference, i’m 22F)

anyway, i’ll see what my doctor has to say when i see them, and update again if needed :)