孤立局灶型机化性肺炎的螺旋CT评价

Evaluation of focal organizing pneumonia with spiral CT

目的探讨机化性肺炎的螺旋CT表现。方法对31例机化性肺炎经胸部平扫与增强扫描的螺旋CT表现进行回顾性分析,评价病变的发生部位、形态、大小、边缘、密度及增强等影像学特点。结果右肺22例(70%),左肺9例(30%)。病灶直径介于0.8～7.0 cm。20例呈团块、片状(65%),10例(32%)呈结节状,1例(3%)呈梭形。形态不规则者27例(87%),表现为楔形、多角形,边缘模糊,形态规则4例(13%),边缘光滑。17例(55%)病灶密度不均匀,其中14例病灶内可见低密度,3例可见空洞;14例(45%)病灶密度均匀。平扫低密度区及空洞增强后无强化,其余实变区域强化明显,强化前后CT差值平均约44 HU。6例(19%)病灶相邻胸膜腔少量局限性积液。结论孤立局灶型机化性肺炎的螺旋CT表现具有一定的特异性,有助于临床的诊断。

Objective To assess the imaging features of solitary focal organizing pneumonia（SFOP） seen on spiral CT.Methods Thirty-one patients with SFOP underwent precontrast and postcontrast spiral CT scans of the chest.The CT findings induding the location,shape,size,margin,attenuation and enhanced pattern of the lesions were analyzed retrospectively.Results The lesions occuned in right and left lungs were 22（70%） and 9（30%） cases,respectively.The diameters of lesions ranged from 0.8 cm to 7.0 cm.The mass-like or patchy lesions were found in 20（65%）,nodular lesions in 10（32%）,and spindle lesions in 1（3%）.Irregular and regular lesions were found in 27（87%） and 4（13%） cases,respectively,the former appeared as wedged or multiangular sphape with ill-definde margin,while the latter appeared as regular shape with smooth margin.The lesions of inhomogeneous density were found in 17 cases,which comprised 14 intralesional hypodense and 3 intralesional cavities,while the lesions of homogeneous density were found in 14 cases.After contrast-enhanced scans,hypodense areas and cavities seen on precontrast CT images had no enhancement but remainder consolidation areas had significant enhancement with 44 HU value.Focal pleural effusion adjacent to the lesions was found in 6（19%） cases.Conclusion Specific findings of SFOP could be demonstrated by spiral CT,which may contribute to clinical diagnosis.