肾移植术后肺部特异性感染的CT表现

CT Imaging Features of Specific Pulmonary Infection in Kidney Transplantation Patients

目的探讨肾移植术后特异性肺感染的CT影像表现,提高对特异性肺炎的影像学特点的认识。方法回顾49例肾移植术后合并肺部特异性感染的病例,其中男31例,女18例,年龄21～60岁,平均年龄42岁。发病时间分别为肾移植术后12d～7年。49例患者均进行了胸部螺旋CT及高分辨CT(HRCT)扫描,扫描范围自肺尖至膈面,螺旋CT扫描层厚5mm,层间距5mm;HRCT扫描层厚1mm或0.625mm,层间距10mm。其中侵袭性肺曲霉菌病29例,卡氏肺囊虫肺炎12例,巨细胞病毒肺炎4例,肺结核4例。19例经痰培养证实,20例经纤维支气管镜下肺泡灌洗及支气管肺活检证实,8例经血清学检查证实,2例经尸检证实。影像结果由3位放射科医师进行分析。结果49例患者的CT检查均可见肺内病灶特征性改变。29例侵袭性肺曲霉菌病患者出现最多的肺内异常表现为:肺内磨玻璃影(23/29);多发大小不等结节灶(22/29),支气管血管束周围结节灶(15/29);肺内实变影(18/29),肺内楔形实变影(11/29);晕征(17/29)。12例卡氏肺囊虫肺炎CT影像中均出现肺内弥漫磨玻璃样改变。4例巨细胞病毒肺炎CT影像中都有肺内散在磨玻璃影表现,并伴有小叶间隔增厚;其中3例伴有双肺多发粟粒结节灶;2例伴有胸腔积液。4例肾移植术后肺结核患者的CT影像中均表现为双肺多发粟粒结节灶,其中1例呈"树芽征"表现。结论肾移植术后肺部特异性感染患者中,卡氏肺囊虫肺炎、侵袭性肺曲霉菌病、巨细胞病毒肺炎、肺结核等在CT影像表现上各有特点,CT检查能较早发现肺部异常,并可以在发病早期或病情危重难以获得病原学证据时,通过影像学检查初步判断感染的病原体而得到及时治疗。

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.