目的分析螺旋CT低剂量胃充气 造影扫描在胃癌诊断中的效果。方法 90 例经胃镜检查拟诊胃癌并需要做螺旋CT 检查患者，按就诊顺序随机分成3组，每 组30例。Ａ组参照组采用固定毫安法， 120kv,150mAs；B、C组低剂量组均采用智 能毫安调制法，管电压120KV，使用智能 毫安法，噪声指数SD值分别为12、15，造 影剂均使用碘海醇(300mgI/ml)，1.2ml/ kg，扫描后将原始薄层图像在东芝16排CT Vitrea工作站上进行后处理，将轴位图像 和重组图像传送至NFPACS上，分别记录每 组病例的CT容积剂量指数(CTDIvol)，评 价图像质量。结果 A、B扫描图像质量的 差异不具有统计学意义(P＞0.05)，A、B 组剂量加权指数降低率的差异具有统计学 意义，A、C组间扫描图像质量、剂量加 权指数降低率的差异具有统计学意义(P ＜0.05)，B、C组间扫描图像质量/剂量加 权指数降低率的差异具有统计学意义。结 论 B、C组使用智能毫安调制法可以有效 降低辐射剂量值，Ｂ组扫描条件可以作为 常规扫描方案，以降低辐射剂量；C组图 像质量显示欠佳，容易造成漏诊，该方案 不推荐应用于胃部肿瘤扫描；在不影响诊 断准确性的前提下，在一定范围内减少辐 射剂量可获得与常规剂量相同的影像信息 和图像质量，应该在临床中进行推广和应 用，更好的对胃癌进行诊断，力求减低病 人的辐射量，提高低剂量筛查早期胃癌的 诊断率。

Objective to analyze the value on the low-dose spiral CT scan of inflated stomach in the diagnosis of gastric cancer. Methods 90 cases of stomach cancer diagnosed by endoscopy who need to do spiral CT san examination were divided into three groups averagely in order. A group, the reference group was taking the way of a fixed tube mA, 120 KV, 150 mAs; B,C Group,as the low-dose group were taking the smart mA modulation method, the tube voltage of 120 KV, using smart mA law, the noise index values were SD 12 15, contrast agents are using iohexol (300 mgI/ml) 1.2 ml/kg. After scanning the original image on a thin layer were transferred into Toshiba 16-slice CT Vitrea workstation to do the postprocessing, and then the axial and reconstructive images were sended into NFPACS,the volume CT dose index (CTDIvol) were recorded in cases of each group, finally to evaluate the image quality. Results A, B-scan image quality difference was not statistically significant (P>0.05), the difference of A and B dose weighted index was statistically significant, the image quality between A and C, and their dose-weighted index decreased rate were statistically significant (P<0.05). The image quality and dose-weighted index decreased rate was statistically significant. Conclusions B, C using smart mA modulation can effectively reduce the radiation dose values, and group B scanning conditions can be a conventional scanning program to reduce radiation dose; Group C showed poor image quality, easily lead to misdiagnosis, the program is not recommended in the stomach tumor scans; Without affecting the diagnostic accuracy of the premise, within a certain range to reduce the radiation dose can be obtained the same image information and image quality as the conventional dose, which should be the promoted to apply in clinical practice, it is better for stomach cancer diagnosis and that means it can help to increase the diagnostic rate of low-dose screening.