肺部弥漫性磨玻璃阴影的CT诊断与鉴别诊断

目的探讨以弥漫性磨玻璃阴影为主要表现肺部疾病的CT特征,提高对本类型肺部疾病的诊断以及鉴别诊断水平。方法回顾分析经病理证实以及临床综合诊断121例以弥漫性磨玻璃阴影为主要表现肺部疾病的CT、HRCT及临床资料,总结其各自CT特征,并寻求具有诊断及鉴别诊断价值的CT及HRCT征象。结果121例中,以肺固有结构异常为主的疾病主要为间质性肺炎18例和结缔组织病5例,磨玻璃影主要分布于中、下肺的外周部,且均伴有间质增厚及纤维化征象。以肺气腔充气状态异常为主的疾病有：过敏性肺炎10例、肺出血5例、肺转移瘤3例及肺泡癌2例,磨玻璃影按照肺叶、肺段分布,且伴有或不伴有小叶中心结节、腺泡结节或肿块性病变。以肺内血管外体液量增加为主的疾病有肺水肿21例及肺挫伤5例,肺水肿性磨玻璃影具有沿下垂部分布的趋势,可伴有心影增大及胸腔积液;而肺挫伤性磨玻璃影与外伤部位相关,且在外伤区肺内也具有沿下垂部分布的趋势。以血流灌注异常为主的疾病有肺栓塞11例和白塞氏综合征4例,磨玻璃影位于正常血管所属的高灌注区,而低密度区是栓塞血管所属的低灌注区,多发细小血管栓塞或多发细小动脉炎可形成马赛克样密度。两种因素或两种以上因素异常的疾病有慢性阻塞性肺病25例、肺泡蛋白沉积症7例及病毒性肺炎5例,慢性阻塞性肺病为通气-血流障碍所致,其磨玻璃影与低密度区形成马赛克样改变,常伴有桶状胸;而肺泡蛋白沉积症及病毒性肺炎同时具有气腔和固有肺结构异常,其磨玻璃影是间质性病变与实质性病变共同作用的结果。结论双肺弥漫性磨玻璃影见于多种疾病,通过对其形态、分布、伴随征象及疾病动态变化的分析,可以初步了解其发生的病理学基础和发病机制,结合临床可以缩小拟诊的范围。

CT diagnosis and differential diagnosis of pulmonary diffuse ground-glass opacity

Objective To study the CT features of pulmonary diseases with diffuse ground-glass opacity (DGGO), and to improve diagnostic and differential diagnostic accuracy of theses diseases. Methods The clinical, CT and high-resolution CT(HRCT) materials of 121 cases' DGGO which were proved by pathology or clinical comprehensive diagnosis were retrospectively analyzed, and its CT features were summarized. The valuable diagnostic and differential diagnostic signs were investigated. Results In these 121 cases, 23 cases were the diseases with abnormity of inherent pulmonary structures, including 18 cases' interstitial pneumonia and 5 cases' connective tissue disease. The DGGO had peripherally distributed with interstitial thickening, fibrosis, tractive bronchiectasis or honeycomb shadow. Twenty cases were the diseases with abnormity of pulmonary air-space's filling state, including 10 cases' allergic pneumonia, 5 cases' pulmonary hemorrhage, 3 cases' metastaic neoplasm and 2 cases' alveolar cell carcinoma. The DGGO had centrally distributed with lobular central node, acinose node or mass. 26 cases were the diseases with abnormity of extravascular fluid overload, including 21 cases' pulmonary edema and 5 cases' contusion of lung. The DGGO had distributed pulmonary pendulous region or relative pendulous region. 15 cases were the diseases with abnormity of pulmonary blood's non-homogenous perfusion, including 11 cases' pulmonary embolism and 4 cases' Behcet's syndrome. The DGGO had presented mosaic-fashion's shadow or the DGGO had distributed throughout one lateral lung. 37 cases were the diseases with two or super-two kings of abnormity, including 25 cases' chronic obstructive pulmonary disease, 7 cases' pulmonary alveolar proteinosis and 5 cases' viral pneumonia. The DGGO had presented mosaic-fashion's shadow or geographic change or crazing paving pattern, or the DGGO had centrally distributed with lobular central node, acinose node and interstitial fibrosis. Conclusion DGGO may be seen in various diseases. To analyze the morphology, distribution, concomitant signs and dynamic changes of DGGO can preliminarily comprehend its pathological basis and pathogenic mechanism. In combination with clinical materials, the range of diagnostic possibilities can be shrinked.