High resolution 3D diffusion-weighted breast MRI

描述（由申请人提供）：乳腺癌的早期发现可降低死亡率。对比增强磁共振成像（MRI）被推荐用于筛查乳腺癌高危女性，因为它的灵敏度几乎是X射线乳腺摄影的两倍。不幸的是，静脉注射钆基造影剂大大增加了MRI的成本和潜在风险。我们的目标是在没有静脉造影剂的情况下进行有效的乳腺MRI筛查。最有前途的方法，非造影剂乳腺MRI是扩散加权成像（DWI）。回波平面成像（EPI-）DWI显示肿瘤，因为增加的细胞密度和改变的显微结构限制了水的扩散。然而，EPI-DWI由于乳房中的磁场变化而遭受低分辨率和失真。我们的目标是创建一个强大的替代双回波稳态（DESS）成像的基础上：首先，我们将开发和优化DESS-DWI技术。我们将开发精确的信号模型，使用两个DESS回波中的信号信息，以最大限度地提高扩散加权，并最大限度地降低对混杂因素的敏感性。我们将修改数据采集以纠正运动伪影，并开发后处理方法以从两个交错的DESS-DWI采集生成T2加权图像和扩散图。其次，我们将在患者中测试DESS-DWI。我们建议在接受临床MRI进行高危筛查或乳腺癌评估的患者中，比较DESS-DWI与X线乳腺摄影、标准EPI-DWI和DCE-MRI的灵敏度。我们将在接受MRI进行高风险筛查的患者亚组中比较DESS-DWI与标准DCE-MRI的活检率。这将是稳态扩散加权MRI首次用于乳腺癌。所提出的DESS-DWI技术有几个新的功能。它提供高空间分辨率的3D扫描，以详细显示形态特征。它在单个3D序列中提供了T2成像和扩散灵敏度，比以前的稳态扩散方法具有更好的准确性。它避免了EPI-DWI的失真，提供了前所未有的多参数，逐像素分析和与其他序列相关的能力。在这项工作结束时，我们将开发和测试一种新的无钆方法用于高风险乳腺癌筛查。这些技术的未来临床验证可能使筛查乳腺MRI可用于更广泛的人群，从而改善乳腺癌的早期发现和治疗。 公共卫生相关性：该项目的目标是创建一种精确的磁共振成像（MRI）技术，用于检测乳腺癌，而不需要静脉注射造影剂。该方法是开发和测试一种三维，高分辨率，无失真的脉冲序列，揭示了水在肿瘤中的扩散基本上受到限制。消除钆造影剂将减少乳腺MRI的持续时间、成本、风险和侵入性，使MRI能够更广泛地用于筛查隐匿性、早期、可治疗的乳腺癌。

DESCRIPTION (provided by applicant): Early detection of breast cancer reduces mortality. Contrast-enhanced Magnetic Resonance Imaging (MRI) is recommended for screening women at high risk for breast cancer because it is nearly twice as sensitive as X- ray mammography. Unfortunately, intravenous gadolinium-based contrast agents substantially increase the costs and potential risks of MRI. Our goal is effective breast MRI screening without IV contrast agents. The most promising approach for non-contrast breast MRI is diffusion-weighted imaging (DWI). Echo-planar imaging (EPI-) DWI reveals tumors because increased cellular density and altered microscopic structure restrict water diffusion. However, EPI-DWI suffers from low resolution and distortions due to magnetic field variations in the breast. We aim to create a robust alternative based on double echo in steady-state (DESS) imaging: First, we will develop and optimize the DESS-DWI technique. We will develop accurate signal models that use signal information in both DESS echoes to maximize diffusion weighting and to minimize sensitivity to confounding factors. We will modify data acquisition to correct motion artifacts, and develop post-processing methods to generate T2-weighted images and diffusion maps from two interleaved DESS-DWI acquisitions. Second, we will test DESS-DWI in patients. We propose to compare the sensitivity of DESS-DWI with X-ray mammography, standard EPI-DWI and DCE-MRI in patients undergoing clinical MRI for high-risk screening or breast cancer evaluation. We will compare the biopsy rate precipitated by DESS-DWI with that of standard DCE-MRI in the subgroup of patients who underwent MRI for high-risk screening. This will be the first use of steady-state diffusion-weighted MRI for breast cancer. The proposed DESS-DWI technique has several novel features. It offers 3D scanning with high spatial resolution to show morphologic features in detail. It provides both T2 imaging and diffusion sensitivity in a single 3D sequence with better accuracy than previous steady-state diffusion methods. It avoids the distortions of EPI-DWI, offering unprecedented ability to perform multiparametric, pixel-by-pixel analysis and correlation with other sequences. At the conclusion of this work, we will have developed and tested a new gadolinium-free approach for high-risk breast cancer screening. Future clinical validation of these techniques could make screening breast MRI available to a broader population and thus improve early detection and treatment of breast cancer. PUBLIC HEALTH RELEVANCE: The goal of this project is to create an accurate magnetic resonance imaging (MRI) technique for detecting breast cancer that does not require an intravenous injection of contrast material. The approach is to develop and test a three-dimensional, high-resolution, distortion-free pulse sequence that reveals the substantially restricted diffusion of water in tumors. Eliminating gadolinium contrast material will reduce the duration, cost, risk and invasiveness of breast MRI, enabling MRI to be used more widely to screen for occult, early-stage, treatable breast cancer.