周围型小肺癌的CT表现及检查方法

Appearance and examination method of small peripheral lung carcinoma on CT

目的分析周围型小肺癌的CT表现及检查方法。方法收集经手术病理证实的周围型小肺癌50例,男性27例,女性 23例,年龄49—83岁,平均70岁。全部采用螺旋CT薄层平扫+动态增强扫描,层厚1-3 mm,pitch=1．5-3,其中动态增强扫描分别在注射后不同时相进行薄层扫描,在CT图像上观察病灶的部位、大小、密度、内部结构和边缘特点,并且测量病灶在不同时相的CT值。结果按照CT密度分为三种类型,I型为不伴磨玻璃征的软组织密度结节23例(46％),II型部分实性伴磨玻璃征18例(36％),III型磨玻璃样结节9例(18％)。50例中CT征象有分叶征者38例,毛刺征者38例,支气管气相和空泡征者36例,磨玻璃征者26例,血管聚集征或血管穿过征41例,胸膜凹陷征36例。其中直径<1 cm的磨玻璃或部分磨玻璃结节的血管聚集及穿过征象、空泡征以及支气管气相征出现率高。动态增强扫描对于I型及Ⅱ型结节意义明显,动态增强CT值峰值平均增强了40—50HU,峰值出现的时间在注射造影剂后100-180秒之间。结论检查方法是提高小肺癌检出率的关键;小肺癌的各种CT征象与肺癌的大小以及病理类型有关。

Objective To analyze the appearance and examination method of small lung carcinoma （〈2cm in diameter） on CT. Methods The CT features of small lung carcinoma （〈2cm） 50 patients confirmed with surgical pathology were examined, with 27 men and 23 women, age ranging from 49 to 83 years （ mean 70 years ）. Helical slice CT was performed using Hispeed NX/I and Hispeed CT/i scanner, 125 kV, 200 mA, slice thickness=3 mm, Piteh=1 1.5 or 3.0. Automatic injector with flow rate 3.0-4.0 ml/s administration nonionie contrast medium and total dosage 100 ml. In delaying time was 25 ,60,120,180 and 240s. To observe locus, size, density, internal structure and margin feature of neoplasm on CT image. Results Three CT types of the masses were observed on the basis of tumor density distribution： Type Ⅰ （23/50 46%） with homogeneous sof-tissue density; Type Ⅱ （18/50 36%） with heterogeneous mass compared with partial ground-grass density; Type Ⅲ （9/50 18%） with heterogeneous mass with ground-grass opacity. The CT sign of small lung carcinoma were lobulation （38/50 76%）, indentation （38/50 76%）, vacuole sign and air-bronchogram （36/50 72%）, ground-grass sign （26/50 52%）, vessel concentration or vessel straight through sign （41/50 82%） and pleura ineisure＇s sign（36/50 72%）. Vacuole sign and air-bronchogram, ground-grass sign and vessel eoncentration or vessel straight through sign were more common than speculation, lobulation, indentation seen in the lesion 〈 1cm in diameter. Dynamie enhance scan is important for Ⅰ and Ⅱ type. The peak value of CT density had mean enhanced 40-50 HU after contrast scan. Between 100s to 180s, the CT density arrived at peak value. Conclusion To promote detected probability of small lung carcinoma, it is key to adopt propriety-detected method. The CT appearances were well correlated with the type of histology, and the size of the small lung carcinoma.