Quantitative evaluation of bone marrow microenvironment of the lumbar and sacroiliac joints in ankylosing spondylitis by MRI mDixon-Quant

Motivation: The development of ankylosing spondylitis(AS) is associated with alterations in bone marrow microenvironment. Goal(s): To quantitatively analyze changes and correlations of the lumbar and sacroiliac joints bone marrow microenvironment in AS using MRI mDixon-Quant. Approach: Fat fraction (FF) and T2* were measured in the lumbar, bone marrow edema (BME), fat metaplasia (FM) of sacroiliac joints. Results: FF value in the lumbar of the AS group demonstrated a significant increase compared to the normal control group, positively correlating with FF value in FM of sacroiliac joints. FF and T2* showed significant differences between BME and FM in sacroiliac joints. Impact: FF and T2* values help to quantitatively analyze variations in the bone marrow microenvironment of lumbar and sacroiliac joints in AS, providing MRI evidence for the mechanism of osteoporosis in AS, while also guiding clinical treatment for inflammation-associated osteopenia.