Development of Radiofrequency Hardware for Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is an imaging modality for diagnosing diseases and aiding treatment based on the nuclear magnetic resonance phenomenon. Radiofrequency coils are utilized for transmission and reception of signals in MRI. This work explores MRI coil and hardware designs and fabrication processes that increase image quality, improve patient comfort, and make it faster and simpler to produce.

This work reports on a 16-channel bilateral breast coil array for high-resolution MR imaging at 3 T which can be used for both prone and supine breast MRI. This closed coil design aims to improve signal-to-noise ratio (SNR) by positioning the coil array close to the breast. In contrast to open coil designs commonly found in clinical coils, increased sensitivity of the coils allows for improved accuracy of breast cancer diagnosis.

This report also proposes a modular stretchable coil using conductive thread technology through the embroidery machine manufacturing process. The coil design increases customizability of coil arrays for individual patients and each body part. The proposed array design allows for highly stretchable, flexible, modular, and conformal patient-centered coils that allow for increased imaging quality, greater comfort, and rapid production.

Furthermore, this work reports on the development of an automated and parametric design of 3D-printed floating common-mode cable traps, which increases the manufacturing speed and increases the shield current attenuation of coaxial cables, which in turn improves SNR and safety of the MRI scan. The techniques and fabrication processes from this work will be used to develop application-specific MRI hardware to improve SNR and patient comfort.

Finally, this work reports on a superheterodyne electronics solution to reduce off-resonance effects of stretched and compressed coils. The work eliminates ferromagnetic components commonly found in other solutions, allowing it to be used inside the MRI bore, and enables for the use of embedded electronics in MRI coils.