基于锥光束乳腺CT的乳腺腺体空间识别与密度容积定量测量方法研究

Breast cancer is the most common cancer among women in many countries. In recent years, great progress has been made in identifying groups of women with high risk who could potentially benefit from early detection and other advances in breast cancer treatment. Breast density has been accepted as an important indicator of breast cancer risk. X-ray mammography, though the most accessible breast imaging modality, has limitations for breast density assessment. As a two-dimensional imaging modality, mammography offers only projection images, which cannot reveal the volumetric density of the breast accurately. Other studies are seeking quantitative assessment of volumetric breast density with modalities such as chest CT and MRI. However, chest CT has high radiation dose, and MRI has high cost and long imaging time. Both modalities cannot become primary modalities of breast imaging. Cone Beam Breast CT (CBBCT) is a new breast imaging modality. It has true three-dimensional images, fast scan speed, high isotropic spatial resolution, with the glandular dose within the range of diagnostic mammography. In this study, the automatic quantitative volumetric density measurement will be applied to CBBCT images. The results will be compared with regular visual density classification with BI-RADS categories. The agreement between these two methods will be assessed. The relationship between volumetric density and age, body mass index(BMI), expression levels of estrogen receptor (ER) and progesterone receptor(PR) will be analyzed in patients with breast cancer. The volumetric density of the study group (cancer group) and the control group (normal group) will be compared to study the relationship of volumetric density and breast cancer risk. The clinical application study of CBBCT is just getting started in China. It is estimated that CBBCT will play an important role in breast cancer risk assessment, early detection, and treatment evaluation.

乳腺癌是女性最常见的恶性肿瘤，乳腺癌的防治备受关注。乳腺密度被认为是一个独立的乳腺癌危险因素，可以预测罹患乳腺癌的危险性。利用乳腺X线摄影二维图像所估算的乳腺密度不能反映乳腺三维组织构成的真实情况。胸部CT可三维测量乳腺密度，但辐射剂量较大。MRI亦可三维测量乳腺密度，鉴于其检查费用较高，成像时间较长，难以得到广泛推广应用。锥光束乳腺CT(CBBCT)是一种新型的乳腺检查手段，具有三维图像逼真、扫描速度快、空间分辨率高且各向同性等优点。锥光束乳腺CT辐射安全性等同于乳腺钼靶X线检查。本研究采用容积定量测量CBBCT上乳腺密度，明确其与通过视觉评估乳腺密度之间的相关性，分析年龄、BMI、ER及PR对乳腺密度的影响，以及比较乳腺癌组与正常对照组乳腺密度的差异，探讨其对预测乳腺癌危险度的价值。锥光束乳腺CT在国内的临床研究刚刚开展，有望在预测乳腺癌危险度、乳腺癌早诊及疗效评估中发挥更大作用。

研究背景：乳腺密度被认为是一个独立的乳腺癌危险因素，可以预测罹患乳腺癌的危险性。利用乳腺X线摄影二维图像所估算的乳腺密度不能反映乳腺三维组织构成的真实情况。锥光束乳腺CT(CBBCT)是一种新型的乳腺检查手段，具有三维图像逼真、扫描速度快、空间分辨率高且各向同性等优点。研究内容：采用容积定量测量CBBCT上乳腺密度，明确其与通过视觉评估乳腺密度之间的相关性，分析年龄、BMI、ER及PR对乳腺密度的影响，探讨其对预测乳腺癌危险度的价值。研究结论及意义：基于CBBCT图像及乳腺X线图像评估乳腺密度的观察者内一致性均较高；不同经验医师在人工视觉评估乳腺密度上具有统计学差异；基于CBBCT图像的乳腺密度定量测量稳定性高，其结果与患者年龄及BMI呈负相关。锥光束乳腺CT在国内的临床研究刚刚开展，有望在预测乳腺癌危险度、乳腺癌早诊及疗效评估中发挥更大作用。