Zompatori M, Poletti V, Battista G, Canini R, Bruscoli P, Carfagnini F
Radiologia Padiglione Pneumonefrologico, Policlinico S. Orsola-Malpighi, Bologna.
Radiol Med. 1997 Oct;94(4):308-14.
Obliterative or constrictive bronchiolitis is characterized by narrowing of the small airways, due to submucosal and peribronchiolar fibrosis, with chronic obstruction. The vast majority of cases of bronchiolitis obliterans are associated with other diseases and only few cases are idiopathic. We report on the main computed tomography (CT) methods used study obliterative bronchiolitis, the CT findings and the differential diagnosis with other diseases. The dynamic study of alveolar ventilation with CT uses inspiratory and expiratory CT or high-resolution CT (HRCT), spiral dynamic CT or HRCT with advanced image display, ultrafast CT. In abnormal cases HRCT shows direct and indirect signs of small airways disease. The most common (> 80%) sign of obliterative bronchiolitis is the so-called mosaic oligohemia, with low attenuating lobules, caused by air trapping and best seen on expiratory CT, associated with blood flow redistribution to more normal lobules; this finding simulates the ground-glass pattern from infiltrative lung disease. Differential diagnosis is more difficult in the presence of true ground-glass patterns associated with diffuse bronchiolar obstruction and also with mosaic oligohemia due to pulmonary vascular disease and pulmonary emphysema. HRCT can distinguish these diseases and dynamic CT is more sensitive than functional tests in detecting regional abnormalities and air trapping. The combination of HRCT, rapid volumetric scanning and advanced image display is a powerful tool study the normal and abnormal features of bronchiolar function and alveolar ventilation.
闭塞性细支气管炎的特征是小气道因黏膜下和细支气管周围纤维化而狭窄，并伴有慢性阻塞。绝大多数闭塞性细支气管炎病例与其他疾病相关，仅有少数病例为特发性。我们报告了用于研究闭塞性细支气管炎的主要计算机断层扫描（CT）方法、CT表现以及与其他疾病的鉴别诊断。利用CT对肺泡通气进行动态研究采用吸气和呼气CT或高分辨率CT（HRCT）、螺旋动态CT或具有先进图像显示功能的HRCT、超速CT。在异常病例中，HRCT显示小气道疾病的直接和间接征象。闭塞性细支气管炎最常见（>80%）的征象是所谓的马赛克血流减少，表现为低衰减小叶，由气体潴留引起，在呼气CT上最易观察到，同时伴有血流重新分布至更正常的小叶；这一表现类似于浸润性肺疾病的磨玻璃样表现。当存在与弥漫性细支气管阻塞相关的真正磨玻璃样表现以及因肺血管疾病和肺气肿导致的马赛克血流减少时，鉴别诊断更为困难。HRCT能够区分这些疾病，并且动态CT在检测局部异常和气体潴留方面比功能检查更为敏感。HRCT、快速容积扫描和先进图像显示的联合应用是研究细支气管功能和肺泡通气的正常及异常特征的有力工具。
