Capturing Central uiSNR at Ultrahigh Field: Number and Size of the Receive Elements Matter

Motivation: In addition to peripheral SNR gain, the promise of a quadratic increase of SNR at the center of a human head with field strength draws significant attention to many ultrahigh field head MRI applications. Goal(s): Assess the performance of state-of-the-art RF receive array coils in capturing the theoretical upper limit of central head SNR across different field strengths. Approach: We experimentally investigated the impact of combining transceiver elements with highly-dense conventional loop arrays to capture the ultimate intrinsic SNR in head applications. Results: We demonstrated that achieving central SNR gains at UHF requires an increased number of receive elements and larger transceiver elements. Impact: Capability of conventional loop technology to capture the SNR's upper-limit in human head is investigated across different field strengths, which can pave the way for the RF technology developments focused on capturing the SNR gain in ultrahigh field head applications.