Truong, Trong-KhaCuthbertson, Jonathan2018-05-312020-05-152018https://hdl.handle.net/10161/17050<p>Magnetic resonance imaging (MRI) generates anatomical images by utilizing a homogeneous static magnetic field (B0) generated by a magnet and radiofrequency (RF) signals transmitted to and received from the subject by RF coils. To enhance the acquired signal strength and improve the image signal-to-noise ratio, receive RF coils are placed close to the surface of the subject and multiple RF coil elements are typically combined to form an RF coil array. The number of RF coil elements in an array has continually increased over the years, requiring large cables, connectors, and added electronic components to be connected to the MRI scanner for imaging, which increases the integration complexity, cost, and weight of the RF coil arrays. Additionally, RF coil arrays are typically heavy and rigid, which makes them difficult and time consuming to setup and uncomfortable for the subjects. Finally, additional shim coils are required to correct for B0 inhomogeneities induced by the subject and to improve the image quality, but they currently provide suboptimal results. This work presents a highly innovative RF coil design to address all of these concerns.</p><p>First, a novel integrated RF/wireless coil design was proposed to enable simultaneous MR image acquisition and wireless communication with a single coil, thereby reducing or eliminating the wired connections for data transfer between the coil and the MRI scanner. Second, the RF/wireless coil design was combined with the integrated parallel reception, excitation, and shimming (iPRES) coil design to enable simultaneous MR image acquisition, wireless communication, and localized B0 shimming with a single coil, thereby further improving the B0 homogeneity and image quality (iPRES-W coil). Finally, the iPRES-W coil design was integrated with: 1) the revolutionary AIR coil technology to perform the same three functions, but with a flexible and ultra-lightweight coil, thereby increasing patient comfort and offering more flexible coil design opportunities and 2) a wireless bidirectional DC power supply for B0 shimming to further eliminate any cables between the MRI scanner and RF coil (iPRES-W AIR coil). </p><p>Experiments were conducted to demonstrate that the modifications made to the RF coil, to enable wireless communication and B0 shimming, did not degrade its imaging performance. Additionally, experiments were conducted to test the wireless data connection, transmission rate, and quality of the wireless link for the RF/wireless and iPRES-W coil designs. Finally, experiments were conducted to demonstrate the ability of the iPRES-W coil to simultaneously perform localized B0 shimming during wireless data transmission and image acquisition. The results presented show no degradation in image quality with the modifications made, excellent B0 shimming performance, and the ability to wirelessly transmit data within the MRI scanner bore. The iPRES-W coil design requires no modifications to the current MRI scanner and leads to a highly scalable, cost effective, wireless solution for a more efficient, comfortable, and beneficial MRI experience.</p>Medical imagingElectrical engineeringFlexible RF coilMagnetic resonance imagingRadio frequency coilShimmingWirelessMaster's thesis