Abstract: Objective To investigate the CT findings in specific pulmonary infection in kidney transplantation patients. And thereby to improve the knowledge of CT imaging features of these disease. Methods A retrospective analysis was carried out in 49 patients with specific pulmonary infection after kidney transplantation. There were 31 males and 18 females, the age ranged from 21 to 60 years(mean 42 years). The time duration from renal transplantation to onset of illness was 12 days to 7 years. Forty-nine patients underwent plain CT and high resolution(HR) CT scans of the chest. In helical CT mode at 1∶ 1 pitch, by using 5 mm beam collimation. HRCT mode used 1mm or 0.625 mm beam collimation, the interval was 10mm.The spectrum of infections included invasive pulmonary aspergillosis in 29 patients, pneumocystis carinii pneumonia in 12 patients, cytomegalovirus pneumonia in 4 patients and pulmonary tuberculosis in 4 patients. Final diagnosis was obtained by sputum culture in 19 patients, bronchoalveolar lavage(BAL) and transbronchial biopsy in 20 patients, blood culture in 8 patients, and on autopsy 2 patients. The findings on chest CT were interpreted by three radiologists. Results The 49 patients showed the typical findings on chest CT. Twenty-two of 29 invasive pulmonary aspergillosis on CT typically showed multiple nodules, 17 of 22 typically showed nodules surrounded by a halo of ground-glass haze(halo sign), 15 of 22 showed peribronchovascular nodules, 23 of 29 showed ground-glass opacity, 18 of 29 showed consolidation; 11 of 29 showed wedge-shaped consolidation. Twelve cases with pneumocystis carinii pneumonia typically showed diffuse ground-glass opacity on CT, 4 of cytomegalovirus pneumonia cases typically showed interstitial pneumonia on CT, ground-glass opacity with thick interlobular septum, 3 of 4 showed ground-glass opacity with small multiple nodules; 2 of 4 showed pleural fluid. CT of 4 cases with pulmonary tuberculosis showed miliary shadows, 1 of 4 showed tree-in-bud sign. Conclusion There are some characteristics in the CT films of patients with different specific pulmonary infection after kidney transplantation. CT findings helped in promp diagnosis of the underlying diseases in these patients.

Key words: pulmonary infection, kidney transplantation, tomography, X-ray computed