1. A magnetic resonance method comprising: shimming a multi-channel transmit coil or coil system to determine optimized operating parameters for radio frequency transmit channels of the multi-channel transmit coil or coil system; acquiring a coil sensitivity map for a magnetic resonance receive element using the multi-channel transmit coil or coil system; acquiring magnetic resonance imaging data using the magnetic resonance receive element and the multi-channel transmit coil or coil system operated with the optimized operating parameters determined by the shimming; and reconstructing a magnetic resonance image from the acquired magnetic resonance imaging data, the reconstructing including performing a constant level correction using the coil sensitivity map acquired using the multi-channel transmit coil or coil system operating with the optimized operating parameters determined by the shimming.