2012/08/08 by Ryan Brown, Guillaume Madelin, Riccardo Lattanzi +4 · 2 citations
Chemistry · Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #Advanced NMR Techniques and Applications #Atomic and Subatomic Physics Research
paper · doi:10.1002/mrm.24432
openalex publication_date 2012/08/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
The critical design aim for a sodium/proton coil is to maximize sodium sensitivity and transmit field homogeneity while simultaneously providing adequate proton sensitivity and homogeneity. While most dual-frequency coils use lossy high-impedance trap circuits or PIN diodes to allow dual-resonance, we explored a nested-coil design for sodium/proton knee imaging at 7 T. A stand-alone eight-channel sodium receive array was implemented without standard dual-resonance circuitry to provide improved sodium signal-to-noise ratio. A detunable sodium birdcage was added for homogeneous sodium excitation and a four-channel proton transmit-receive array was added to provide anatomical reference imaging and B0 shimming capabilities. Both additional modules were implemented with minimal disturbance to the eight-channel sodium array by managing their respective resonances and geometrical arrangement. In vivo sodium signal-to-noise ratio was 1.2-1.7 times greater in the developed eight-channel array than in a mononuclear sodium birdcage coil, whereas the developed four-channel proton array provided signal-to-noise ratio similar to that of a commercial mononuclear proton birdcage coil.