Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA.
School of Medicine, University of Pennsylvania Medical Center, Philadelphia, PA.
Chest. 2013 Dec;144(6):1883-1892. doi: 10.1378/chest.13-1270.
Multiple causes for tree-in-bud (TIB) opacities have been reported. However, to our knowledge the relative frequencies of the causes have not been evaluated. The purpose of this study was to determine the relative frequency of causes of TIB opacities and identify patterns of disease associated with TIB opacities.
Cases with TIB opacities in the radiology report in 2010 were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of TIB opacities. Patterns of disease associated with TIB opacities were evaluated.
Causes for TIB opacities were established in 166 of 406 (40.9%) cases. Respiratory infections (119 of 166, 72%) with mycobacteria (65 of 166, 39%), bacteria (44 of 166, 27%), viruses (four of 166, 3%), or multiple organisms (six of 166, 4%) were most common. Aspiration was the cause in 42 of 166 (25%). Alternating areas of normal lung with regions of small airways disease (TIB opacities, bronchiectasis) (random small airways pattern) was specific (0.92) for Mycobacterium avium complex infection. Nearly uniform distribution of bronchiectasis (widespread bronchiectasis pattern) was specific for "diseases predisposing to airway infection" (specificity 0.92), such as cystic fibrosis, primary ciliary dyskinesia, allergic bronchopulmonary aspergillosis, and immunodeficiency states. Consolidation and TIB opacities (bronchopneumonia pattern) were usually due to bacterial infection or aspiration. Dependent distribution (specificity 0.79) and esophageal abnormality (specificity 0.86) with TIB opacities were associated with aspiration. Chronicity of findings was associated with mycobacterial infection (P < .0001, sensitivity 0.96). Acuteness of findings was associated with bacterial infection (P < .001, specificity 0.87).
TIB opacities are most often a manifestation of infections or aspiration. Patterns of disease can provide clues to the most likely diagnosis.
树芽征（TIB）密度增加的病因有多种报道。然而，据我们所知，这些病因的相对频率尚未得到评估。本研究的目的是确定 TIB 密度增加的病因的相对频率，并确定与 TIB 密度增加相关的疾病模式。
通过在放射学信息系统中搜索，确定了 2010 年放射学报告中 TIB 密度增加的病例。查阅病历和 CT 扫描检查以确定 TIB 密度增加的病因。评估与 TIB 密度增加相关的疾病模式。
在 406 例病例中，确定了 166 例（40.9%）TIB 密度增加的病因。以分枝杆菌（166 例中的 65 例，39%）、细菌（166 例中的 44 例，27%）、病毒（166 例中的 4 例，3%）或多种病原体（166 例中的 6 例，4%）引起的呼吸道感染（119 例，72%）最常见。42 例（166 例中的 25%）病因是吸入。正常肺与小气道疾病（TIB 密度增加，支气管扩张）交替区域（随机小气道模式）的存在特异性（0.92）提示感染鸟分枝杆菌复合体。几乎均匀分布的支气管扩张（广泛支气管扩张模式）特异性提示“易发生气道感染的疾病”（特异性 0.92），如囊性纤维化、原发性纤毛运动障碍、变应性支气管肺曲霉病和免疫缺陷状态。TIB 密度增加与实变（支气管肺炎模式）通常是细菌感染或吸入的结果。TIB 密度增加时的依赖性分布（特异性 0.79）和食管异常（特异性 0.86）与吸入有关。发现的慢性与分枝杆菌感染有关（P <.0001，敏感性 0.96）。发现的急性与细菌感染有关（P <.001，特异性 0.87）。
TIB 密度增加最常表现为感染或吸入。疾病模式可以为最可能的诊断提供线索。
