目的 :探讨不同 CT检查技术在三维适形放疗定位中的应用。方法 :采用 CT直接增强扫描、CT窗技术和应用 CT扫描参数对 95例癌症患者行三维适形放疗 CT定位并进行观察和照相。再由 CT诊断医师在 CT图像上逐层勾画靶区轮廓、身体轮廓、敏感器官体积。结果 :15例患者未行增强扫描显示病灶欠佳 ,其余 90例行直接增强扫描病灶显示率达 10 0 %。 2窄窗仅清楚显示病灶 ,对体表轮廓及定位标记物显示欠佳 ,而宽窗则相反 ,只有中间窗可同时显示两者且显示率达 10 0 %。结论 :1增强 CT定位更能清晰显示病灶的密度、轮廓和边缘 ,尤以增强 2～ 4 min内显影最佳 ,更利于勾画病灶的体积 ;2适当调节窗宽和窗位能同时显示病灶、体表轮廓及定位标记点 Objective: To explore the application of different CT examination techniques in three-dimensional conformal radiotherapy. Methods: Ninety-five patients with cancer underwent three-dimensional conformal radiotherapy (CT) localization and observation and photography using direct contrast-enhanced CT scan, CT window technique and CT scan. Then by the CT diagnostic physicians on the CT image layer by layer outlined outline of the target area, body contour, sensitive organ volume. Results: In 15 cases, the enhancement scan showed that the lesion was not good, and the remaining 90 cases showed direct contrast-enhanced scan of 100%. 2 Narrow windows show only clear lesions, poorly displayed body contour and positioning markers, and wide windows, on the contrary, only the middle window displays both and shows a 10% display rate. Conclusions: 1 Enhanced CT localization can clearly show the density, contour and edge of lesions, especially in the enhancement of 2 ~ 4 min in the best development, more conducive to outline the size of the lesion; 2 Appropriate adjustment of window width and window level can display lesions, Body contour and positioning points