乳腺癌是女性常见癌症之一，乳腺癌区域的精准检测对乳腺癌的治疗有至关重要的作用。本文采用频率为2.52THz的连续太赫兹波反射式成像系统，对小鼠在体皮下乳腺癌模型进行了太赫兹波成像检测。研究结果表明，太赫兹波成像可以清晰识别出乳腺癌区域，且与肉眼可见肿瘤区域一致。在体乳腺癌区域的太赫兹波相对反射率高于正常组织，两者相对反射率差值高达15%。进一步，对距离皮肤表面不同深度的离体乳腺癌组织进行切片和苏木精-伊红（H&E）染色，作为金标准对照。结果发现乳腺癌区域的面积随着距离皮肤表面深度的增加而增大。通过将太赫兹波成像与H&E染色结果对比可知，在距离皮肤表面约460μm处，太赫兹波图像和H&E染色图中的肿瘤区域面积相等。由此可知，太赫兹波对在体皮下乳腺癌的探测深度大约在460μm左右，太赫兹波有望实现深部肿瘤的检测。

Breast cancer （BC） is one of the most common diseases in women. The accurate detection for BC is very important in clinical practice. In this paper， in-vivo breast cancer in a subcutaneous xenograft mouse was studied with the continuous-wave terahertz （THz） reflection imaging system at 2.52THz. The high reflection region in THz images of in-vivo subcutaneous xenograft mouse corresponded well to the tumor area in visible. The difference value of 15% between tumor and normal tissues was observed. For the gold standard， the tumor areas at different depths from the surface of skin in mouse model were obtained by hematoxylin and eosin-stained images. The tumor areas increased with the increase of depth. In contrast with THz image， it is found that the tumor area in THz image was similar to that in hematoxylin and eosin-stained images at a depth of 460μm. Therefore， the detection depth of THz wave to in-vivo breast cancer in subcutaneous xenograft mouse modelis about 460μm， and THz wave is expected to realize the detection of deep tumors.