DUAL TUNED HELMHOLTZ COIL FOR BREAST CANCER IMAGING

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 临床乳腺检查对发现乳腺肿瘤的特异性和敏感性有限。即使是用于早期筛查乳腺肿瘤的X射线乳房X光检查，其敏感性也有限，无法发现大约25%的乳腺癌。动态增强磁共振成像(DCE-MRI)具有高敏感性但低特异性，即癌和良性病变均增强[2]。其他成像手段，如钠(23Na)磁共振有可能提高乳腺癌的敏感性和特异性 检测是因为~(23)Na核磁共振可以反映膜钠钾泵的紊乱与肿瘤的发生有关。此外，梯度硬件和脉冲序列的最新进展使23Na磁共振用于钠浓度的定量测量成为可能。 使用只接收H表面线圈和发射/接收23Na表面线圈的多核MRI的初步结果显示，肿瘤中23Na信号升高。尽管表面线圈提供了高信噪比图像，但 B1非均质性符合毕奥-萨伐尔定律。为了量化乳房中的23Na浓度，我们需要一个射频线圈来改善B1的均质性 而不牺牲信噪比。这项研究的目标是建立一个双调谐亥姆霍兹线圈，以研究 双调谐亥姆霍兹线圈和双调谐表面线圈的不同之处在于为多核成像提供高信噪比和高质量的B1均一性，并使用双调谐亥姆霍兹线圈执行初步乳房成像。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Clinical breast exams have limited specificity and sensitivity for detecting breast tumors. Even X-ray mammography, which is used for early screening of breast tumors, has limited sensitivity and does not detect approximately25% of breast cancers. Dynamic contrast-enhanced MRI (DCE-MRI) has high sensitivity but low specificity; i.e., both cancerous and benign lesions enhance [2]. Additional imaging modalities such as sodium (23Na) MR have the potential to increase the sensitivity and specificity of breast cancer detection because 23Na MR can reflect the disruption of the membrane Na-K pump associated with cancer. Moreover, recent advances in gradient hardware and pulse sequences have made 23Na MR feasible for quantitative measurements of sodium concentration. Preliminary results of multinuclear MRI using a receive-only H surface coil and a transmit/ receive 23Na surface coil show elevated 23Na signal in the tumor. Although the surface coil provides high SNR images, there is significant B1 inhomogeneity as modeled by Biot-Savart's law. For quantifying 23Na concentration in the breast, we need an RF coil that improves B1 homogeneity without sacrificing SNR. The goals of this study were to build a dual-tuned Helmholtz coil, to investigate the difference between a dual-tuned Helmholtz coil and a dual-tuned surface coil in providing high SNR and high quality B1 homogeneity for multinuclear imaging, and to perform preliminary breast imaging using the dual-tuned Helmholtz coil.