DUAL TUNED HELMHOLTZ COIL FOR BREAST CANCER IMAGING

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 中心，不一定是研究者的机构。 临床乳腺检查检测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线摄影术，灵敏度也有限，无法检测到约25%的乳腺癌。动态对比增强MRI（DCE-MRI）具有高灵敏度但低特异性;即，癌性和良性病变均增强[2]。其他成像方式，如钠（23 Na）MR，有可能提高乳腺癌的灵敏度和特异性 因为23 Na MR可以反映与癌症相关的膜Na-K泵的破坏。此外，梯度硬件和脉冲序列的最新进展使23 Na MR定量测量钠浓度成为可能。 使用仅接收H表面线圈和发射/接收23 Na表面线圈的多核MRI的初步结果显示肿瘤中的23 Na信号升高。虽然表面线圈提供高SNR图像，但存在显著的 B1不均匀性，由Biot-Savart定律建模。为了定量乳腺中的23 Na浓度，我们需要一个提高B1均匀性的RF线圈 而不牺牲SNR。本研究的目的是建立一个双调谐亥姆霍兹线圈， 双调谐亥姆霍兹线圈和双调谐表面线圈在为多核成像提供高SNR和高质量B1均匀性方面的差异，以及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.