Objective. We report a case of large vessel vasculitis, compare imaging techniques, and briefly review the literature.Methods. Anticardiolipin antibody titers, acutephase response, and ischemic symptoms in a 50-year-old man admitted for treatment of vasculitis-related ischemia of the fingers were monitored over a 1Cmonth period. Images from serial magnetic resonance angiography (MRA) were compared with images from conventional arteriography in the evaluation of peripheral arterial circulation.Results. The acute-phase response and anticardiolipin antibody levels were found to vary in parallel with slow resolution of ischemic symptoms following monthly treatment with pulse methylprednisolone and cyclophosphamide.Conclusion. Attribution of ischemic symptoms to anticardiolipin antibody is supported by the correlation of anticardiolipin antibody titers, acute-phase response parameters, and ischemic symptoms. The serial images from MRA demonstrate its usefulness as a noninvasive tool for followup studies of both large and medium-sized vessels affected by vasculitis.A pathogenetic role for anticardiolipin antibodies in endothelial activation and thrombosis seems certain, but the putative mechanisms remain speculative (1-5). Dispute remains about whether true vasculitis with neutrophilic infiltrations of media in larger vessels can be attributed to anticardiolipin antibody (6,7). We report the case of a 50-year-old man with widespread vascular disease of the extremities which we believe to be vasculitis, based on the results of extensive serial imaging, monitoring of the acutephase response, and the clinical failure of anticoagulation therapy with subsequent success of therapy with intravenous pulse methylprednisolone and cyclophosphamide . CASE REPORTThe patient was a 50-year-old man with a history of myocardial infarction (1988) and recent coronary artery bypass grafting (1993). Raynaud's phenomenon, with negative antinuclear antibody (ANA), had been diagnosed 10 years previously. No previous tests for anticardiolipin antibodies or lupus anticoagulant had been performed. The patient presented with numbness and bluish discoloration of 3 fingers of 1 hand; there were no rashes or other cutaneous signs. He was admitted to the hospital for treatment of ischemia of the fingers. Initial laboratory studies revealed an erythrocyte sedimentation rate (Westergren) of 31 mmhour, negative ANA, and normal levels of anticardiolipin antibodies (IgG 28 optical density [OD] units [normal <34], IgM 14 OD units [normal <231). Cryoglobulins were initially present, but disappeared on repeat testing prior to treatment. Angiography of the left arm revealed severe occlusive disease of the radial and ulnar arteries with gradual tapering of the vessels (not shown). There was no change in the arteriographic picture after intraarterial administration of nitroglycerin.The following laboratory studies performed later yielded normal or negative results: rheumatoid factor testing, measurement of C3 and C4 levels (118 mgldl and 60 mgldl, respective...