Assessment of Breast Cancer Risk with High Spectral and Spatial Resolution MRI

描述（由申请人提供）：我们建议测试HiSS MRI是否比传统的脂肪抑制MRI和X射线乳腺摄影更准确地估计乳腺癌风险。乳腺密度是乳腺癌最强的独立风险因素之一，对乳腺密度进行可靠的测量可以显著改善风险管理和预防性治疗。X射线乳腺摄影术预测人群癌症风险增加，但由于实质和脂肪分离的错误以及实质体积测量的错误，对指导个体患者治疗的价值有限。MRI允许对乳房实质进行3D成像，并检测来自水和脂肪的独立信号。MRI检测到他莫昔芬和雷洛昔芬导致乳腺密度显著降低。然而，常规MRI需要抑制来自乳房中脂肪的信号。脂肪抑制有时是不均匀的，并且脂肪抑制脉冲影响水共振，从而降低实质体积测量的准确性。因此，我们提出了一种测量乳腺癌风险的创新方法：我们将使用高光谱和空间分辨率MR成像（HiSS MRI）可靠地分离水和脂肪信号，并定量测量实质密度和他莫昔芬引起的乳腺密度变化。我们假设使用定量HiSS成像将减少变异性，标准化测量，并增加对实质体积变化的敏感性。此外，HiSS可以基于HiSS图像的增强纹理的新型计算机辅助诊断（CAD）分析和脂肪分布的HiSS图像提供新的风险标记。该提案建立在该实验室在临床磁体上实施HiSS MRI的工作基础上，并证明了这种方法的显著优势。我们提出了以下具体目标：目标#1：使用HiSS MRI实现乳房实质密度和形态的定量全双侧测量。将使用附着在乳房上的质子束来准确测量MRI可检测的质子密度。新型软件将评估实质体积和纹理。脂肪分布和组成将作为风险的额外标志物进行检测。目标2。比较HiSS与传统方法：我们将比较HiSS、传统脂肪抑制MRI、狄克逊MRI方法和X线乳腺摄影测量的乳腺密度。乳腺密度的测量将包括绝对和部分实质体积，以及MRI可检测的水质子密度。将比较HiSS和常规MRI测量的变异性。目标3。测量由于选择性雌激素受体调节剂（SERM）治疗引起的实质密度变化：作为HiSS MRI对乳腺癌风险变化的敏感性的测量，我们建议对已知可降低风险的预防性治疗的反应进行成像。我们将比较HiSS MRI对他莫昔芬治疗效果的敏感性与2D X射线乳腺摄影和常规MRI的敏感性。

DESCRIPTION (provided by applicant): We propose to test whether HiSS MRI estimates breast cancer risk more accurately than conventional fat- suppressed MRI and X-ray mammography. Reliable measurements of breast density, which is one of the strongest independent risk factors for breast cancer, could significantly improve management of risk and preventive treatment. X-ray mammography predicts increased cancer risk on a population basis but has limited value for guiding treatment of individual patients, due to errors in separation of parenchyma and fat, and errors in measurement of the parenchymal volume. MRI allows 3D imaging of breast parenchyma and detects independent signals from water and fat. MRI detects significant decreases in breast density due to tamoxifen and raloxifen. However, conventional MRI requires suppression of signals from fat in the breast. Fat suppression is sometimes non-uniform and fat suppression pulses affect the water resonance, reducing the accuracy of parenchymal volume measurements. Therefore we propose an innovative approach to measurement of breast cancer risk: We will use high spectral and spatial resolution MR imaging (HiSS MRI) to reliably separate water and fat signals, and to quantitatively measure parenchymal density and changes in breast density due to tamoxifen. We hypothesize that use of quantitative HiSS imaging will reduce variability, standardize measurements, and increase sensitivity to variations in parenchymal volume. In addition, HiSS may provide new markers for risk based on the novel computer-aided diagnosis (CAD) analysis of the enhanced texture of HiSS images, and HiSS images of fat distribution. This proposal builds on work in this laboratory that implemented HiSS MRI on clinical magnets and demonstrated significant advantages of this approach. We propose the following Specific Aims: Aim #1: Implement quantitative full bilateral measurements of breast parenchymal density and morphology with HiSS MRI. Phantoms attached to the breast will be used to accurately measure MRI- detectable proton density. Novel software will evaluate parenchymal volume and texture. Fat distribution and composition will be tested as additional markers for risk. Aim #2. Compare HiSS with conventional approaches: We will compare breast density measured with HiSS, conventional fat-suppressed MRI, Dixon MRI methods, and X-ray mammography. Measures of breast density will include absolute and fractional parenchymal volume, and MRI-detectable water proton density. The variability of HiSS and conventional MRI measurements will be compared. Aim #3. Measure changes in parenchymal density due to selective estrogen receptor modulator (SERM) therapy: As a measure of the sensitivity of HiSS MRI to changes in breast cancer risk, we propose to image response to preventive therapy that is known to reduce risk. We will compare the sensitivity of HiSS MRI to effects of tamoxifen therapy with that of 2D X-ray mammography and conventional MRI.