Proton MRSI of Human Breast Cancer at 3 and 7 Tesla

描述(申请人提供)：乳腺癌是女性最常见的癌症。2004年，据估计，美国新诊断的乳腺癌病例约为21.7万例，其中有4万人死于乳腺癌。乳腺癌成功治疗的关键是早期诊断，而广泛使用的乳房X光检查已显著提高了乳腺癌的存活率。然而，乳房X光检查的一个主要问题是缺乏特异性；在一些研究中，在转诊为活检的乳房X光检查可疑病变中，有70%-80%最终诊断为良性。这些“不必要的”活组织检查给医疗保健系统带来了巨大的经济负担，而且对患者来说也是侵入性的，令人不快。因此，有必要开发新的非侵入性、成本效益和安全的诊断成像程序，以提高特异性和灵敏度。质子磁共振波谱成像(MRSI)是一种非侵入性代谢成像技术，有望用于人类乳腺癌的非侵袭性诊断。来自我们小组和其他人的初步数据表明，胆碱信号的升高(在质子磁共振光谱中检测到)是恶性乳腺疾病的标志。然而，质子磁共振成像的低信噪比目前将这种方法限制在相当大的病变(例如1厘米或更大)，并使检测小CHO信号变得困难。此外，以前很少有研究调查CHO在乳腺癌病变中的空间分布。因此，在这项建议中，我们建议在高场磁共振系统(3和7特斯拉)上开发磁共振成像方法，这些系统有望表现出比低场扫描仪更高的灵敏度和分辨率。将开发出在短扫描时间内在高磁场下完全覆盖乳房的方法，使用相控阵接收器线圈，以及最佳的水和脂肪抑制。还将开发定量测定病变胆碱浓度的方法。这些方法将在第一年和第二年开发，在第三年到第五年，将研究MRSI的临床价值。具体地说，胆碱水平将在预定进行乳房活检的患者的组织学类型(恶性和良性)之间进行比较。质子磁共振成像在这组患者中的敏感性和特异性将被确定，并在不同的场强之间进行比较。此外，在同一人群中，MRSI的诊断价值将与常规MRI的诊断价值进行比较。

DESCRIPTION (provided by applicant): Breast cancer is the most common form of cancer in women. In the year 2004, it was estimated that approximately 217,000 new cases of breast cancer were diagnosed in the United States, and that 40,000 deaths were attributed to the disease. The key to successful treatment of breast cancer is early diagnosis, and the use of widespread mammography screening has resulted in significant improvements in breast cancer survival rates. However, a major problem with mammography is a lack of specificity; in some studies, as many of 70-80% of suspicious lesions on mammography referred for biopsy ultimately have a benign final diagnosis. These 'unnecessary" biopsies represent a significant economic burden on health care systems, and are also invasive and unpleasant for the patient. Therefore, there is a need for the development of new non-invasive, cost-effective, and safe diagnostic imaging procedures with enhanced specificity and sensitivity. Proton MR spectroscopic imaging (MRSI) is a non-invasive metabolic imaging technique that shows promise for the non-invasive diagnosis of human breast cancer. Preliminary data from our group and others suggests that an elevated choline signal (detected in the proton MR spectrum) is a marker of malignant breast disease. However, the low signal-to-noise ratio of proton MRSI currently limits this methodology to quite large lesions (e.g. 1 cm or greater), and makes detection of small Cho signals difficult. Also, few previous studies have investigated the spatial distribution of Cho in breast cancer lesions. In this proposal, we therefore propose to develop methods for MRSI on high field MR systems (3 and 7 Tesla) that are expected to exhibit higher sensitivity and resolution than lower field scanners. Methods will be developed for full breast coverage at high magnetic fields in short scan times, using phased-array receiver coils, and optimal water and lipid suppression. Methods will also be developed for the quantitative determination of lesion choline concentrations. These methods will be developed in years 1 and 2, and, in years 3 through 5, the clinical value of MRSI will be investigated. Specifically, choline levels will be compared between histologically defined tissue types (malignant and benign), in patients who are scheduled for breast biopsy. The sensitivity and specificity of proton MRSI in this patient group will be determined, and compared between field strengths. In addition, the diagnostic value of MRSI will be compared to that of conventional MRI in the same population.