Improving the Specificity of Breast MRI Through Improved DWI

描述(申请人提供)：乳房核磁共振正被临床广泛接受，被用于筛查高危女性，并进一步调查可疑的超声或乳房X光检查结果。动态增强(DCE)成像中局部增强模式的观察是MRI乳腺检查的支柱，具有接近完美的病变检测灵敏度。然而，目前的方案表现出不太理想的特异性；根据报告，多达5例阳性MRI检查中有4例可能导致阴性活检和心烦意乱的患者。最近提出的提高乳腺MRI特异性和减少假阳性和阴性活检数量的方法之一是扩散加权成像(DWI)，这是一种在几微米范围内探测水分子流动性的方法。新出现的研究，主要是在1.5T下进行的，指出弥散加权成像有可能减少高达33%的DCE阳性结果所保证的活检，而不会漏掉任何癌症。随着3T扫描仪成为临床标准，通过DWI采集可以赋予DCE方案的乳腺癌诊断的特异度的提高程度还有待确定。与高场下乳腺解剖成像相关的许多问题，例如图像阴影、B0不均匀引起的伪影、不当的脂肪抑制和低通道数的乳腺RF接收线圈，使得3T DWI空间分辨率在10-40ml范围内，类似于1.5T，明显低于3T DCE MRI协议典型的1ml分辨率。我们提出的这项研究代表了一种多方面的、全面的方法，以了解3T弥散加权成像提高乳腺癌检测的特异性的最终潜力。更具体地说，我们建议开发能够在不到5分钟内获得减少伪影、高空间分辨率和扩散加权图像的技术。将研究一些方法，以确保均匀的信号激励、高灵敏度的信号接收，以及减轻主场不均匀对扩散加权图像质量的影响。开发的硬件和软件将借给我们的临床合作伙伴贝丝以色列女执事医疗中心，在那里，将在临床研究中评估单独使用DWI测量以及作为DCE MRI辅助诊断乳腺癌的性能。 与公共健康相关：这项研究代表了一种多方面的、全面的方法，以了解扩散加权(DW)磁共振成像提高乳腺癌检测的最终潜力。将对影响DW图像质量的硬件和采集方法进行改进。由于这些改进而提高的MRI乳腺癌检测特异度将在一项小型临床研究中量化。

DESCRIPTION (provided by applicant): MRI of the breast is gaining widespread clinical acceptance, being used to screen high-risk women and to further investigate questionable ultra-sound or mammography findings. The observation of the local pattern of enhancement in dynamic contrast enhanced (DCE) imaging is the pillar of the MRI breast exams, yielding close to perfect lesion detection sensitivity. Less than ideal specificity, however, is exhibited by the current protocols; depending on the report, up to 4 out of 5 positive MRI exams may result in negative biopsies and distraught patients. One of the methods recently proposed for increasing breast MRI specificity and reducing the number of false positives and negative biopsies is diffusion weighted imaging (DWI), an approach which probes the mobility of water molecules on a scale up to a few microns. Emerging studies, mainly performed at 1.5T, point to the potential of DWI to reduce up to 33% of the biopsies warranted by positive DCE results, without missing any cancers. As 3T scanners become the clinical standard, the extent of the improvement in specificity of breast cancer diagnosis that can be imparted to a DCE protocol by DWI acquisitions is yet to be determined. A number of problems associated with imaging the breast anatomy at high fields, such as image shading, artifacts due to B0 inhomogeneities, improper fat suppression and low channel count breast RF receive coils available commercially, have left the 3T DWI spatial resolution in the 10-40ml range, similar to 1.5T, and significantly below the 1ml resolution typical of 3T DCE MRI protocols. The research we propose represents a multi-faceted, comprehensive approach toward understanding the ultimate potential of 3T DWI to improve the specificity of breast cancer detection. More specifically, we propose to develop technology resulting in the acquisition of reduced artifact, high spatial resolution, and diffusion weighted images in less than 5 minutes. A number of approaches for insuring homogeneous signal excitation, high sensitivity signal reception, and mitigating the impact of main field inhomogeneity on diffusion weighted image quality will be studied. The hardware and software developed will be loaned to our clinical partner, Beth Israel Deaconess Medical Center, where the performance of DWI measurements alone and as an adjuvant to DCE MRI in diagnosing breast cancer will be assessed in a clinical study. PUBLIC HEALTH RELEVANCE: The research proposed represents a multi-faceted, comprehensive approach towards understanding the ultimate potential of diffusion weighted (DW) MRI to improve breast cancer detection. Improvements to hardware and acquisition approaches that impact DW image quality will be performed. The increase in MRI breast cancer detection specificity due to these improvements will be quantified in a small clinical study.