Proton MRSI of Human Breast Cancer at 3 and 7 Tesla

描述（由申请人提供）：乳腺癌是女性中最常见的癌症。2004年，据估计，美国约有21.7万例新的乳腺癌病例被诊断出来，4万人死于这种疾病。成功治疗乳腺癌的关键是早期诊断，广泛使用乳房x光检查已经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，70-80%的乳房x线摄影可疑病变转介活检最终诊断为良性。这些“不必要的”活组织检查给卫生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和不愉快的。因此，有必要开发新的无创、经济、安全的诊断成像程序，提高特异性和敏感性。质子磁共振光谱成像（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入性诊断。我们小组和其他人的初步数据表明，胆碱信号升高（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MRSI的低信噪比目前限制了这种方法用于相当大的病变（例如1厘米或更大），并且很难检测到小的Cho信号。此外，对Cho在乳腺癌病变中的空间分布研究较少。因此，在本提案中，我们建议在高场MR系统（3和7特斯拉）上开发MRSI方法，以期比低场扫描仪具有更高的灵敏度和分辨率。将开发在短扫描时间内使用相控阵接收器线圈在高磁场下完全覆盖乳房的方法，以及最佳的水和脂质抑制。还将开发用于定量测定病变胆碱浓度的方法。这些方法将在第1年和第2年发展，在第3年到第5年，将研究mri的临床价值。具体来说，胆碱水平将比较组织学上确定的组织类型（恶性和良性），在计划进行乳腺活检的患者。将确定质子MRSI在该患者组中的敏感性和特异性，并与场强进行比较。此外，MRSI的诊断价值将与常规MRI在相同人群中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.