Diffusion Weighted Breast MR Imaging for Screening Women with Dense Breasts

描述(申请人提供)：弥散加权成像(DWI)有可能成为超声的安全、经济有效的替代品，作为乳房X光检查的补充程序，筛查40%-50%的乳房致密妇女，以确定有可疑乳房病变的妇女。研究人员开发了两种正在申请专利的方法，以提高使用(DWI)检测乳腺癌的敏感性：(1)分析病变边缘的ADC梯度，(2)增强扩散图像，以提高病变与背景组织的区分性。在第一阶段的研究中，新的方法成功地检测和区分了高比例的乳房病变，没有因为成像问题或患者运动而排斥任何病例。在第二阶段，研究人员将使用新的方法开发一个计算机辅助诊断(CAD)系统的原型，并将通过读者研究来评估性能。在DWI中，检测乳腺癌的主要指标是表观扩散系数(ADC)。其他扩散测量需要扩散张量成像(DTI)，这是一种成像过程，所需时间是DWI的两倍，而且更难进行成本论证。使用标准方法，ADC有两个关键缺点，即由于成像问题和患者运动而导致的低灵敏度和高排斥率，这阻碍了DWI在乳腺癌检测中的临床应用。在第一阶段制定的两种创新方法提高了敏感性，在第一阶段可行性研究中的拒绝率为零。在乳房致密的女性中，乳房X光检查和超声波检查都漏掉了相当大比例的乳腺癌。动态对比增强(DCE)MRI筛查具有很高的敏感性，但不推荐用于筛查乳腺癌风险较低或中等的女性。美国癌症协会建议，当女性的风险高于20%时，DCE用于乳腺癌筛查。当高乳房密度是唯一的风险因素时，这一门槛是达不到的。该项目的长期目标是开发一种临床上和商业上可行的用于评估DWI图像的CAD系统，当该系统与乳房X光检查结合使用时，能够识别那些乳房致密的女性，她们患乳腺癌的风险超过20%的ACS阈值，因此后续的DCE筛查是合理的。

DESCRIPTION (provided by applicant): Diffusion Weighted Imaging (DWI) has the potential for being a safe, cost-effective alternative to ultrasound as a supplemental procedure to mammography for screening the 40%-50% of women with dense breasts to identify women who have suspicious breasts lesions. The investigators have developed two patent-pending methods for improving sensitivity in detection of breast cancer using (DWI): (1) Analyzing ADC gradient at the lesion border, and (2) Enhancing diffusion images to improve differentiation of lesion from background tissue. In the Phase I study, the novel methodologies successfully detected and discriminated a high percentage of breast lesions, without rejecting any cases because of imaging problems or patient motion. In Phase II, the investigators will develop a prototype computer-aided-diagnosis (CAD) system using the novel methodologies and will evaluate performance with a reader study. The primary measurement for detecting breast cancer in DWI is Apparent Diffusion Coefficient (ADC). Other measures of diffusion require Diffusion Tensor Imaging (DTI), an imaging procedure that takes twice as long as DWI and is more difficult to cost-justify. Using standard methodologies, ADC has two critical shortcomings, low sensitivity and high rejection rate due to imaging problems and patient motion, which hinder clinical use of DWI for breast cancer detection. The two innovative methodologies developed in Phase I improved sensitivity and had zero rejection rate in the Phase I feasibility study. Both mammography and ultrasound miss a significant percentage of breast cancers in women with dense breasts. Dynamic Contrast Enhanced (DCE) MRI screening has high sensitivity, but is not recommended for screening women who have a low or moderate risk of breast cancer. The American Cancer Society recommends DCE for breast cancer screening when a women's risk is higher than 20%, a threshold that is not met when high breast density is the only risk factor. The long-range goal of this project is to develop a clinically and commercially viable CAD system for evaluating DWI images which, when used in conjunction with mammography, is able to identify those women with dense breasts who have a breast-cancer risk greater than the 20% ACS threshold for which follow-up DCE screening is cost-justified.