Wegener's Granulomatosis: CT Evolution of Pulmonary Parenchymal Findings in Treated Disease

Objective: To determine the computed tomography (CT) evolution of various pulmonary manifestations of Wegener's Granulomatosis (WG) following appropriate pharmacologic treatment of the disease. Methods: Eleven patients with WG were identified, each of whom had had at least two CT examinations. CTs were reviewed retrospectively to identify pulmonary lesions of WG. Lesions were categorized as nodules, cavities, lobar atelectasis, pulmonary bands, or infiltrates. To determine the evolution of each individual lesion following pharmacologic treatment, the authors compared the lesions at presentation to their appearances on follow-up CT examinations. Results: A total of 112 lesions were identified (nodules = 70, cavities = 25, lobar atelectasis = 7, pulmonary bands = 6, infiltrates = 4). The mean time interval between CT examinations was 34 weeks (range: 3-248 weeks). Treated nodules tended to become smaller (33/70, 47%), to resolve (14/70, 20%), or to remain unchanged (8/70, 11%). However, the nodules became larger or cavitated in a substantial minority of cases (13/70, 19% and 2/70, 3%, respectively). Although more than half of the treated cavities became smaller (13/25, 52%) or resolved (1/25, 4%), many evolved into nodules (6/25, 24%) or enlarged (5/25, 20%). All cases of lobar atelectasis (14/14, 100%) and transpulmonary bands (6/6, 100%) were unchanged at follow-up. All infiltrates were either resolved (3/4, 75%) or substantially improved (1/4, 25%). Conclusion: WG has a wide spectrum of pulmonary manifestations. Nodules, cavities, and infiltrates are among the most common lesions seen on CT. Although these findings tend to improve with treatment, mixed responses are not uncommon. Lobar atelectasis and transpulmonary bands tend not to improve, even with the occurrence of clinical disease remission.