Differences and Similarities of High-resolution Computed Tomography Features Between Pneumocystis Pneumonia and Cytomegalovirus Pneumonia in Aids Patients

Abstract

Background: Accurate differentiating diagnosis of pneumocystis pneumonia and cytomegalovirus pneumonia is crucial for choosing therapies in AIDS patients. Hence, the purposes of this study was to compare the CT features of pneumocystis pneumonia and cytomegalovirus pneumonia in AIDS patients and to spot the valuable findings which might contribute to an accurate diagnosis between two cohorts.MethodsA total of 112 AIDS patients, 78 withpneumocystis pneumoniaand 34 werecytomegalovirus pneumonia,were included in this study.Two experienced chest radiologists retrospectively reviewed CT images for 17 features including ground-glass opacity, consolidation, nodules, and halo sign. Significance was calculated by the chi-square(χ2)test.ResultsThe presence of consolidation (61.77% in cytomegalovirus pneumonia,35.9% in pneumocystis pneumonia, p=0.011), halo signs (32.35% in cytomegalovirus pneumonia, 11.54% in pneumocystis pneumonia, p＜0.001), and nodules (47.06% in cytomegalovirus pneumonia,8.97% in pneumocystis pneumonia, p＜0.001), especially small nodules (32.5% in cytomegalovirus pneumonia, 6.41% in pneumocystis pneumonia, p＜0.001) without perilymphatic distribution,was significantly more frequent in patients with cytomegalovirus pneumonia than in those with pneumocystis pneumonia. Large nodules were not found in any of patients with cytomegalovirus pneumonia. The presence of ground-glass opacity (100% in pneumocystis pneumonia and cytomegalovirus pneumonia), reticulation(57.69% in pneumocystis pneumonia, 52.94% in cytomegalovirus pneumonia, p=0.782) andbronchial wall thickening (34.62% in pneumocystis pneumonia, 47.06% in cytomegalovirus pneumonia, p=0.213) were common in both groups.ConclusionsAnalysis of consolidation, nodules, and halo signs may contribute to prioritize differential diagnosis of pneumocystis pneumonia or cytomegalovirus pneumonia. However, some CT features considered typicalin oneor other diseases appear with similar frequency in both cohorts of AIDS patients.