|dc.description.abstract||Breast cancer is the second leading cause of cancer death among females in the United States. Magnetic resonance imaging (MRI) has emerged as a powerful tool for detecting and evaluating the disease, with notable advantages over other modalities, and the advent of ultra-high field strength scanners promises even more potential. In comparison to standard clinical MRI field strengths (1.5, 3.0 tesla), breast MRI at 7T provides increased signal-to-noise ratio (SNR) and spectral resolution. These benefits, however, are accompanied by significant challenges in hardware design, limiting the availability of commercial radiofrequency coils for 7T.
The primary objective of this work is to enable the study of breast cancer at 7T with the development of a 16-channel receive array coil. The use of array coils to receive is standard in clinical MRI, as it provides higher SNR over a field of view than a single coil. In this case, when combined with the increased sensitivity provided by the high field strength, this will enable the ability to acquire images with higher resolution than could be achieved at 3T or 1.5T in clinically standard scan times. This has the potential to improve the morphological characterization of tumors and their involvement in the surrounding tissues.
This thesis discusses the design and construction of a 16-channel receive array insert, characterization of its performance as an array, and comparison of the achievable SNR to a transmit-receive quadrature volume coil. With the 16-channel receive array insert, the results demonstrate a 6.5 times improvement in mean SNR and the ability to accelerate up to a reduction factor of 9 with a mean g-factor of 1.3. Finally, we present initial in vivo images acquired with the array, demonstrating the utility of the array coil through higher resolution imaging than the current protocols at lower field strengths.||en