Magnetic resonance imaging findings in primary amyloidosis-associated arthropathy.

The MRI findings of amyloid arthropathy associated with primary amyloidosis are presented here possibly for the first time in the literature. Two types of lesions are noted: (1) capsular and tendon lesions; these regions are thickened, hypointense and enhanced by gadolinium (Gd) on T1 weighted imaging (T1WI), and hyperintense on T2 weighted imaging (T2WI), and (2) periarticular and osseous lesions; these regions appear to be tumor-forming and hypointense on both T1WI and T2WI and are not enhanced by Gd. It is necessary to differentiate these findings from other diseases such as chondrosarcoma, rhabdomyosarcoma and chronic inflammatory lesions such as tuberculosis.