小肺癌的HRCT特征及其诊断价值

The Value of HRCT Features in the Early Diagnosis of Small Lung Cancer

目的 进一步探讨小肺癌的HRCT影像学特征,提高术前诊断的准确性。方法 男性45例,女性11例,年龄2 5～76岁,3 0岁以下3例,3 1～5 0岁以下2 2例,5 0岁以上3 1例(占全部病例的5 5 3 % )。手术46例,穿刺活检10例,其中鳞癌16例,腺癌2 9例,细支气管肺泡癌11例;影像学资料:常规扫描从肺尖至肋膈角等距离扫描,其中3 9例作病灶局部的HRCT扫描,增强扫描3 2例,注射造影剂3 0～40s后开始扫描第一期,5min后再对病灶用同一条件做延迟扫描,对扫描资料进行图像后处理,在结节的实质部分分别测量增强前后第一期及延迟扫描的CT值,10例作了病灶的3D、MIP和CTA重建。结果 病灶部位及类型病灶位于右肺3 1例(上叶前段4例,后段1例,中叶11例,下叶15例) ,左肺2 5例(上叶前段2例,舌叶9例,下叶14例) ;结节的HRCT平扫征象:病灶呈类圆形、椭圆形、小结节形及不规则的斑片状影,病灶内见“空泡征”或“细支气管充气征”2 1例,占3 7 5 % ,“小结节堆积征”3 8例;占67 9% ,病灶周围呈分叶者47例(明显分叶3 6例,浅分叶11例) ,占83 9% ,毛刺42例,占75 0 % ,棘状突起5例,占8 9% ,血管纠集7例,占12 5 % ,“胸膜凹陷征”2 8例,占5 0 0 %。增强后表现:其中腺癌2 9例,病灶强化程度为2 6～69Hu ,平均为(4 8 9±17 8)Hu ,细支气管肺泡癌11例,

Objective To study the imaging features on high resolution CT (HRCT) of small lung cancer and to improve the diagnosis rate before surgery. Methods Fifty-five patients, 45 male and 11 female, aged from 25 to 76, 3 (5.5%) under 30 years, 22 (39%) ranging 31-50, 31 (55.3%) over 51. Of 56 cases (46 surgery, 10 biopsy), 16 were squamous cell carcinoma, 29 adenocarcinoma and 11 alveolar cell carcinoma. All underwent routine equal space scan from the top of pulmonary to the costophrenic angle, 39 underwent extra HRCT scan over the lesion, and 32 enhanced scan. The first phase of the scan was done 30-40 s after injection of contrast media, delayed scan was done 5 min later using the same scanning meters. Image post-processing was done in 10 cases, including measuring CT values over the parenchyma part of the lesion in plain and enhanced image, 3-D, MIP and CTA. Results Location and type: Of the 56, the cancer of 31 located in right lung, in which 4 at anterior segment and 1 posterior in the upper lobe, 11 middle and 15 lower lobe, while 25 in left, in which 2 at anterior segment and 9 lingula lobe and 14 lower lobe. HRCT signs: 21 (37.5%) showed round-like, oval, nodular and irregular patchy, air bronchogram, 38 (67.9%) nodular accumulation, 47 (83.9%) lobulation, in which 36 deep and 11 slight, 42 (75.8%) spiculate, 5 (8.9%) spine, 7 (12.9%) convergence sign of pulmonary vessels, 28 (50.0%) pleural indentation. In enhanced images, CT value was increased by 26-69 Hu (mean 48.7±17.8) in the 29 adenocarcinomas, 18-56 Hu (mean 41.8±19.7) in the 11 alveolar cell carcinomas, 31.3-38.9 Hu (mean 35.6±13.7) in the 16 squamous cell carcinomas. Of all the cases, CT value increased by more than 20 Hu was found in 19 (33.9%), more than 30 Hu in 37 (66.1%), and 21 cases still increased by 20-44 Hu (mean 41.8±19.7 Hu) in 5 min delay scan images. In 10 reconstruction images, more detailed signs were found of the lesion, such as nodular accumulation,nodulation, pleural indentation and the arrangement of peripheral vessels. Conclusion In the HRCT signs of small lung cancer, the inside signs such as nodular accumulation, vacuole sign, air bronchogram, especially the enhancement degree and lasting time are more helpful to the diagnosis than those common signs such as nodulation, spiculate.