Erosions at the 'bare area' of the metacarpophalangeal joint on MRI in early rheumatoid arthritis are best identified using which sequence?

• A T2-weighted fast spin-echo without fat suppression
• B Fat-suppressed T1-weighted post-gadolinium sequence ✓
• C Short tau inversion recovery (STIR) sequence
• D Gradient-echo T2* sequence

Explanation

MRI detection of early erosive RA is optimised with fat-suppressed T1-weighted post-gadolinium (contrast-enhanced) sequences. Erosions appear as cortical breaks with enhancement of pannus tissue, and synovitis shows as enhancing thickened synovium. The 'bare area' — intra-articular bone not covered by cartilage — is the earliest site of erosion. STIR and fat-suppressed T2 detect marrow oedema and joint effusion but are less specific for erosion characterisation. Gradient-echo T2* is used for haemosiderin detection (PVNS).

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.