Very fast calibration of the Transmit B1+ field

Measuring the transmit sensitivities (B1+) of individual coil elements is often necessary in 7T body imaging to compensate for inhomogeneities in image contrast and signal. However, this calibration measurement remains a challenge at 7T in human body MRI scans. Especially, when the number of transmit channels is high, the calibration can take several minutes, which poses a problem for in-vivo applications.

In a joint DFG-funded project between the German Cancer Research Center (DKFZ) in Heidelberg and the Physikalisch-Technische Bundesanstalt (PTB) in Berlin, novel deep learning-based approaches are currently being explored. These methods aim to estimate the transmit sensitivities in just a few seconds from localizer scans, which are routinely acquired at the beginning of every examination.

The approach has already been applied successfully in both the head and body. It is expected to be highly beneficial for future clinical 7T applications in the human body, and preliminary data suggest that it will also be relevant for use at field strengths beyond 7 Tesla.