Hi there!
The MRI probably refers to ‘marrow fat replacement’ which is a common association of spondyloarthropathies along with bone marrow edema, joint erosions, and ankylosis; though it may be seen in a few normal individuals as well as a few non-specific conditions.
Hope this was helpful.
Take care!
Thank you doctor for your reply. I want to know one more thing. What are the non-specific conditions related with fat replacement of the SI joints?
Hi there!
Aside being normal in some cases, few drugs, chronic infections, radiation, demineralization, increased age, a few hormonal/ endocrine disorders etc. can cause similar changes. Similar appearance can also be caused due to issues that interfere with signal intensity on the MRI.
Hope this is useful.
Take care!