A Flexible Nested Sodium and Proton Coil Array with Wideband Matching for Knee Cartilage MRI at 3T

作者：Brown Ryan^*; Lakshmanan Karthik; Madelin Guillaume; Alon Leeor; Chang Gregory; Sodickson Daniel K; Regatte Ravinder R; Wiggins Graham C

来源：Magnetic Resonance in Medicine, 2016, 76(4): 1325-1334.

DOI：10.1002/mrm.26017

• dual-tuned
• phased-array
• FLORET
• preamplifier noise
• coupling

Purpose: We describe a 2 x 6 channel sodium/proton array for knee MRI at 3T. Multielement coil arrays are desirable because of well-known signal-to-noise ratio advantages over volume and single-element coils. However, low tissue-coil coupling that is characteristic of coils operating at low frequency can make the potential gains from a phased array difficult to realize.
Methods: The issue of low tissue-coil coupling in the developed six-channel sodium receive array was addressed by implementing 1) a mechanically flexible former to minimize the coil-to-tissue distance and reduce the overall diameter of the array and 2) a wideband matching scheme that counteracts preamplifier noise degradation caused by coil coupling and a high-quality factor. The sodium array was complemented with a nested proton array to enable standard MRI.
Results: The wideband matching scheme and tight-fitting mechanical design contributed to >30% central signal-to-noise ratio gain on the sodium module over a mononuclear sodium birdcage coil, and the performance of the proton module was sufficient for clinical imaging.
Conclusion: We expect the strategies presented in this study to be generally relevant in high-density receive arrays, particularly in x-nuclei or small animal applications.

• 出版日期2016-10