Integrated RF/shim body coil array for MRI with localized shimming

用于 MRI 的集成射频/匀场体线圈阵列，具有局部匀场功能

• 批准号: 9298078
• 负责人: Trong-Kha Truong
• 金额: $ 19.88万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9298078
• 关键词: Abdomen; Address; Air; Body Image; Brain; Brain imaging; Breast; Clinical; Coiled Bodies; Computer software; Development; Diagnostic; Diffusion Magnetic Resonance Imaging; Disease; Early Diagnosis; Echo-Planar Imaging; Elements; Fatty acid glycerol esters; Future; Goals; Gynecology; Head; Human; Image; Imaging Techniques; Kidney; Lesion; Liver; Magnetic Resonance Imaging; Magnetism; Malignant Neoplasms; Maps; Methods; Monitor; Morphologic artifacts; Noise; Organ; Outcome; Pancreas; Patients; Performance; Positron-Emission Tomography; Power Sources; Predisposition; Prostate; Resolution; Scanning; Signal Transduction; Staging; System; Techniques; Technology; Testing; Tissues; Translating; Vertebral column; base; clinical application; clinical practice; cost; design; diagnostic accuracy; experimental study; flexibility; healthy volunteer; improved; in vivo; innovation; magnetic field; new technology; next generation; novel; operation; public health relevance; radiofrequency; reconstruction; simulation; treatment response

Project Summary / Abstract Magnetic susceptibility differences at air/tissue interfaces induce strong localized static magnetic field (B0) inhomogeneities, which cannot be effectively shimmed with the whole-body spherical harmonic (SH) shim coils onboard clinical MRI scanners, resulting in image artifacts such as distortions, blurring, signal loss, and incomplete fat suppression. These artifacts introduce diagnostic inaccuracies in clinical applications and are particularly severe in body imaging, which suffers from more extensive B0 inhomogeneities than brain imaging, and for techniques based on fast imaging sequences such as echo-planar imaging, which is used in many clinical applications such as diffusion-weighted imaging (DWI). Thus, body DWI is one of the most challenging applications and the development of a new technology that can achieve a high B0 homogeneity in the body is critically needed to improve its spatial fidelity and accuracy and to increase its clinical utility. A novel concept, termed integrated parallel reception, excitation, and shimming (iPRES), was recently proposed, which allows a radiofrequency (RF) current and a direct current (DC) to flow in the same coil, thereby enabling RF reception and localized B0 shimming with a single integrated RF/shim coil array. This new technology can thus effectively shim localized B0 inhomogeneities without reducing the signal-to-noise ratio (SNR) or requiring additional space in the magnet bore, which was demonstrated in the human brain with a 32-channel iPRES head coil array. However, its application to body imaging is more challenging, because of the larger coil elements in body coil arrays and the more extensive B0 inhomogeneities. The goal of this proposal is to develop the next generation of iPRES coil design, termed adaptive iPRES(N), to achieve a high B0 homogeneity in the body. Specifically, each RF coil element of a 32-channel body coil array will be divided into N smaller independent DC loops and switches will be added to distribute the DC currents into the appropriate DC loops as needed, resulting in a much higher flexibility and spatial resolution for localized B0 shimming, without requiring additional power supplies. Simulations will first be performed to optimize the coil design (Aim 1). The coil array will then be implemented by using a novel switch technology and will be integrated into a 3T MRI scanner (Aim 2). Finally, it will be validated by performing bench tests, phantom experiments, and human experiments, including high-resolution abdominal DWI (Aim 3). This new technology will provide an unprecedented B0 homogeneity in the body with no SNR penalty, which will substantially improve the spatial fidelity, image quality, diagnostic accuracy, scan efficiency, and patient comfort for a wide range of clinical applications, including body DWI. It will also enable shimming on wide- bore and PET/MR scanners, which do not have SH shim coils, and will eliminate the need for such coils in future scanners, resulting in lower manufacturing costs and a wider magnet bore to fit larger patients.

项目摘要/摘要