局限性机化性肺炎CT表现

目的 分析局限性机化性肺炎(FOP)的影像学征象,探讨FOP的CT诊断价值.方法 回顾性分析57个经手术病理证实的FOP病灶,结节型(长径≤30 mm)40个,肿块型(长径>30 mm)17个,分析FOP分布位置、形态边缘、内部特点及强化特征等CT征象.结果 39个病灶位于右肺,18个病灶位于左肺;51个病灶位于外带肺野,6个病灶位于内中带肺野;FOP在肺叶和肺野分布的差异有统计学意义.FOP常见充气支气管征象(28/57),疏松症(18/57),血管集束征(21/57).49个病灶与胸膜相连,其中34个病灶与胸膜宽基底相连.CT增强扫描54个病灶,动脉期平均增强CT值35 HU,静脉期平均增强CT值45 HU,呈渐进性强化.肿块型FOP多呈不均匀强化(14/17),结节型FOP以均匀强化为主(25/40).肿块型FOP与结节型FOP边缘、形状、磨玻璃影、坏死、空洞、与胸膜相连的差异有统计学意义.结论 FOP的CT表现具有一定的特征性,增强CT扫描结合多平面重组图像有助于鉴别诊断.

CT appearances of focal organizing pneumonia

Objective To analyze the radiologic characteristics of focal organizing pneumonia (FOP) and discuss its values in diagnosis of FOP.Methods 57 lesions of FOP proved by histological examination were studied retrospectively.All of the lesions could be classified into types of nodule(diameter≤30 mm, n=40) and mass(diameter>30 mm, n=17),which were analyzed to explore the imaging characteristics such as location, margin, internal state, and enhancement features.Results 39 lesions were located in the right lung and 18 lesions in the left lung, and 51 lesions in the peripheral and 6 lesions in the inner or middle of the lung.The differences between the location of lobe and lung field were statistically significant.The radiographic common features included air bronchogram were seen in 28 cases, while loose composition sign in 18 cases and vessel convergence in 21 cases.49 lesions occurred in subpleural region, including 34 lesions broad contract with pleura.In 54 lesions with contrast-enhanced CT scan, the difference between arterial phase and plain scan in CT value was 35 HU and difference of venous phase and plain scan was 45 HU, presenting gradual enhancement.14 lesions were inhomogeneous enhancement in mass type and 25 lesions were homogeneous enhancement in nodule type.There were statistic differences in margin, shape, round-glass opacity, necrosis, cave and the relationship with pleura between the nodule type and mass type.Conclusion FOP has specific radiographic features.Enhanced CT scan combining multi planar reformation images is helpful in differential diagnosis.