目的 探讨低剂量CT扫描技术联 合迭代模型重建(IMR)技术在乳腺癌术前 中的应用。方法 选择2014年12月至2017 年11月于我院进行乳腺癌手术的患者60 例，均进行CT乳腺和胸部扫描，分别采用 模型迭代重建(IMR)技术和滤波反射投影 重建(FBP)技术进行图像重建，比较两种 技术客观图像质量[感兴趣区内CT值、噪 声(SD)值、对比噪声比(CNR)]、主观图 像质量[病灶轮廓、伪影、噪声、图像清 晰度]。结果 IMR技术乳腺病灶感兴趣区 内CT值与FBP技术无显著差异(P>0.05)， SD值明显低于FBP技术(P<0.05)，CNR明 显高于FBP技术(P<0.05)。IMR技术乳腺 病灶轮廓、伪影、噪声、图像清晰度 评分均明显高于FBP技术(P<0.05)。IMR 技术胸部伪影、噪声、图像清晰度评 分均明显高于FBP技术(P<0.05)。CT扫 描总剂量为(5.21±1.06)mGy，总ED为 (2.20±0.41)mSy；乳腺动态扫描总剂量 为(1.68±0.49)mGy，ED为(0.63±0.19) mSy。结论 低剂量CT扫描技术联合IMR技 术具有较好图像质量，对乳腺癌术前评估 具有重要临床价值。

Objective To explore the application of low-dose CT scanning combined with iterative model reconstruction (IMR) technique in preoperative diagnosis of breast cancer. Methods A total of 60 cases of breast cancer in our hospital from December 2014 to November 2017 were selected and given CT scanning of breast and chest. Image reconstruction was carried out by using iterative model reconstruction (IMR) and filtered back-projection reconstruction (FBP) respectively. The objective image quality [CT value, noise (SD) value and contrast noise ratio (CNR) of regions of interest] and subjective image quality [lesion contour, artifact, noise and image definition] were compared between the two technologies. Results There was no significant difference in the CT value of breast regions of interest between the IMR technique and the FBP technique (P>0.05), and the SD value was significantly lower than that of the FBP technique (P<0.05) while the CNR was significantly higher than that of the FBP technique (P<0.05). The scores of lesion contour, artifact, noise and image definition of breast by the IMR technique were significantly higher than those by the FBP technique (P<0.05). The scores of artifact, noise and image definition of chest by the IMR technique were significantly higher than those by the FBP technique (P<0.05). The total dose of CT scanning was (5.21±1.06) mGy, and the total ED was (2.20±0.41) mSy. The total dose of breast dynamic scan was (1.68±0.49) mGy, and the ED was (0.63±0.19) mSy. Conclusion Low-dose CT scanning combined with IMR technique has good image quality and has important clinical value in preoperative assessment of breast cancer.