Flexible, 31-Channel breast coil for enhanced parallel imaging performance at 3T

Purpose: To design, build, and characterize the performance of a novel 3T, 31-channel breast coil.

Methods: A flexible breast coil, accommodating all breast sizes while preserving close to unity filling factors in all configurations, was designed and built. Its performance was compared to the performance of the current state-of-the-art, 16 channel breast coil (Sentinelle coil, Hologic, Bedford, MA, USA), in phantoms and in vivo.

Results: Better axilla coverage and lower inter-coil coupling (12% versus 26%, as characterized by the average off-diagonal elements of the noise correlation matrix) was exhibited by our 31-channel coil compared with the 16-channel coil. Breast area signal-to-noise ratio increases of 68% (phantom) and 28% ± 31% (in vivo) were observed when the 31-channel coil was used. For the 31-channel/16-channel arrays, respectively, two-dimensional acceleration factors of left/right × superior/inferior = 4.3 × 2.4 resulted in average g-factors of 1.10/1.68 (in vitro) and 1.28/2.75 (in vivo); acceleration factors of left/right × anterior/posterior = 3.0 × 2.8 resulted in average g-factors of 1.06/1.54 (in vitro) and 1.05/1.12 (in vivo).

Conclusion: A high performance breast coil was built; its capabilities were demonstrated in phantom and normal volunteer imaging experiments.