In the European Congress of Rheumatology 2022 (EULAR 2022) on the rheumatologic disease management, Dr. Sevtap Tugce Ulas from the Charité Universitätsmedizin of Berlin, Germany, presented her study on gender-specific differences in magnetic resonance imaging (MRI) among patients with axial spondyloarthritis (axSpA).¹

Evidence from scientific literature and clinical practice has shed light on the existence of gender differences in axSpA, with men having a higher risk of damage and women having a higher risk of peripheral manifestations, such as pain, stiffness and fatigue.1Women have shown a higher disease activity and a lower response to therapy than men.¹ Low back pain was more associated with degenerative or mechanical stress-induced diseases among women.¹The differences in joint biomechanics among gender may be areas on behind these disparities and can contribute to the delayed disease diagnosis in females.¹

As imaging is an important tool in the diagnostic work-up of axSpA, this study was conducted to compare the diagnostic performance of MRI findings between men and women.¹

In this post-hoc analysis, MRI images of the standard T1-weighted scan and the short-TI inversion recovery (STIR) sequence were obtained, while erosion, sclerosis, bone marrow edema, fat metaplasia and ankylosis were assessed at 3 joint levels, namely the ventral, middle and dorsal levels.¹

In this study, patients from 6 different perspective of axSpA cohorts were included. Of the 684 patients identified with clinical diagnosis and complete imaging data, 379 were men and women with axSpA, and 305 were without axSpA.¹

Baseline characteristics showed equal distribution of men and women with no major gender differences for erosions and bone marrow edema.¹ However, there was a significantly higher prevalence of fat metaplasia in men and sclerosis in women.¹

The results demonstrated a significant difference between men and women in all parameters, with the most significant difference observed for ankylosis showing a 10x stronger performance in men.¹ Dr. Ulas explained that this difference was not only due to the low prevalence in females, but also the higher rates of false positives.1Furthermore, erosion and fat metaplasia were also slightly higher in men, while sclerosis and bone marrow edema were higher in women.¹

Moreover, Dr. Ulas acknowledged the limitations of the study, including the use of a conventional T1-weighted spin-echo sequence that may overestimate damage, the intensity of bone marrow edema was not a part of the semi-quantitative scoring system, and the MRI images under investigation were used in the diagnostic process, which carried the risk of circular reasoning.¹

In conclusion, differences in the imaging appearance between men and women exist, except for bone marrow edema, and that the diagnostic performance on MRI is lower in women as ankylosis leads to false positives in females.¹ These findings might spark future revision on the appropriateness of incorporating sex-specific recommendations in the imagining criteria.¹