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Double-tuned 31P/1H human head array with high performance at both frequencies for spectroscopic imaging at 9.4T
{PURPOSE: To develop a robust design of a human head double-tuned 31 P/1 H array, which provides good performance at both 31 P and 1 H frequencies for MR spectroscopic imaging at 9.4T. METHODS: Increasing the number of surface loops in a human head array improves the peripheral signal-to-noise ratio (SNR), while the central SNR doesn\textquotesinglet substantially change. High peripheral SNR can contaminate MR spectroscopic imaging data at both 1 H and 31 P frequency. To minimize this effect, we limited the number of elements in the 31 P array to 10, i.e., 8 transceiver surface loops circumscribing the head and 2 receive "vertical" loops placed at the superior location. The 1 H-portion of the array also consists of 10 elements, i.e., 8 transceiver surface loops circumscribing the head and 2 transceiver "vertical" loops at the superior location of the head. Both the 31 P array and 1 H array are placed in a single layer at the same distance to the head, which provides high loading and, thus, a good performance for both arrays. RESULTS: Transmit efficiency of the 1 H-portion of the double-tuned array was very similar to that of the single-tuned arrays of similar size. Also, addition of the cross-loops substantially improved the brain coverage. CONCLUSION: We developed a novel 31 P/1 H double-tuned array for MR spectroscopic imaging of a human brain at 9.4T. Placing both 31 P and 1 H loops in a single layer provides for high transmit efficiency at both frequencies without compromising SNR near the brain center at the 31 P-frequency. Addition of the cross-loops at the superior location improves the brain coverage.}
@article{item_3190551, title = {{Double-tuned 31P/1H human head array with high performance at both frequencies for spectroscopic imaging at 9.4T}}, journal = {{Magnetic Resonance in Medicine}}, abstract = {{PURPOSE: To develop a robust design of a human head double-tuned 31 P/1 H array, which provides good performance at both 31 P and 1 H frequencies for MR spectroscopic imaging at 9.4T. METHODS: Increasing the number of surface loops in a human head array improves the peripheral signal-to-noise ratio (SNR), while the central SNR doesn\textquotesinglet substantially change. High peripheral SNR can contaminate MR spectroscopic imaging data at both 1 H and 31 P frequency. To minimize this effect, we limited the number of elements in the 31 P array to 10, i.e., 8 transceiver surface loops circumscribing the head and 2 receive "vertical" loops placed at the superior location. The 1 H-portion of the array also consists of 10 elements, i.e., 8 transceiver surface loops circumscribing the head and 2 transceiver "vertical" loops at the superior location of the head. Both the 31 P array and 1 H array are placed in a single layer at the same distance to the head, which provides high loading and, thus, a good performance for both arrays. RESULTS: Transmit efficiency of the 1 H-portion of the double-tuned array was very similar to that of the single-tuned arrays of similar size. Also, addition of the cross-loops substantially improved the brain coverage. CONCLUSION: We developed a novel 31 P/1 H double-tuned array for MR spectroscopic imaging of a human brain at 9.4T. Placing both 31 P and 1 H loops in a single layer provides for high transmit efficiency at both frequencies without compromising SNR near the brain center at the 31 P-frequency. Addition of the cross-loops at the superior location improves the brain coverage.}}, volume = {84}, number = {2}, pages = {1076--1089}, publisher = {Wiley-Liss}, address = {New York}, year = {2020}, slug = {item_3190551}, author = {Avdievich, NI and Ruhm, L and Dorst, J and Scheffler, K and Korzowski, A and Henning, A} }