SVD analysis of Array transmission and reception and its use for bootstrapping calibration

Noise-optimal reconstruction of array transmitter calibrations would ideally require knowledge of the receive array sensitivities which can often only be measured once the transmitter is calibrated to provide sufficient coverage. This poses often a problem in bootstrapping transmit-receive arrays particularly at ultrahigh fields.

Said problem is resolved by formulating the local transmit-receive efficiency of the array setup as a bilinear form and deriving therefrom a noise-optimal, joint reconstruction of the calibration data resulting in the relative sensitivities of the used transmitters and receivers.

Retrieval and reconstruction of parallel transmission calibration data in phantoms and in vivo are presented using an eight-channel parallel transmit setup with up to 16 receivers using strip-line TR arrays and parallel transmission by traveling waves.

Data sets from calibration scans are reconstructed robustly and with optimal signal-to-noise ratio. The found array signal gain is furthermore a direct performance measure for array transmitter and receiver combinations. The concomitantly obtained image was shown to have maximum coverage of the subject. Magn Reson Med 76:1730-1740, 2016. © 2016 International Society for Magnetic Resonance in Medicine.