Lead arthropathy: radiographic, CT and MRI findings

Abstract

Lead arthropathy is a well-known complication of gunshot injuries with retained intra-articular bullets. Although several previous reports have discussed the radiological findings of this entity, computed tomography (CT) and magnetic resonance imaging (MRI) findings have never been described before in this setting. In this paper the authors review the imaging findings of 11 patients with lead arthropathy (1 of whom had clinical signs of lead poisoning as well), all of them studied by means of radiographs. In addition, non-enhanced CT scans were obtained in 3 patients and gadolinium-enhanced MRI in 1. Classic findings of intra-articular speckled lead deposits (occasionally with a "lead arthrogram" appearance), joint space narrowing and preserved bone density were found at radiographs in the great majority of cases. Furthermore, extension of intra-articular lead to adjacent tendon sheaths was observed in almost half of the patients, an observation rarely reported in the literature. CT scans and MRI, in their turn, were superior with regard to soft tissue abnormalities, accurately depicting joint effusion and the thickened synovium with lead particles embedded in it. Post-gadolinium MRI had the advantage of showing the enhancement pattern of the inflamed synovium and associated bone marrow edema pattern. Although it is not possible to establish the role of axial imaging in lead arthropathy from the small number of cases studied, this initial experience shows that both methods hold promise in this setting and may be useful, at least in selected cases.