Patent ID: 8686726

Claim:
A magnetic resonance system comprising: a magnetic resonance scanner including a multi-channel radio frequency (RF) transmit system; an RF shimming processor configured to compute complex amplitude values for operative channels of the multi-channel RF transmit system based on a figure-of-merit comprising a weighted combination of a B 1 uniformity measure and a total power measure; and an RF transmit sub-system configured to drive the multi-channel RF transmit system to excite magnetic resonance using the complex amplitude values computed by the RF shimming processor for the operative channels of the multi-channel RF transmit system, wherein the figure-of-merit comprising a weighted combination of the B1 uniformity measure and the total power measure is of a form of Î´ = âŒ© ( T tot â¡ ( x ) - âŒ© T tot â¡ ( x ) âŒª ) 2 âŒª + Î» âŒ© T tot â¡ ( x ) âŒª 2 â¢ âˆ‘ n = 1 N â¢ â¢ A n 2 where spatial parameter x spans the volume of interest, where operator < . . . > denotes a statistical average or expectation over the volume-of-interest T tot â¡ ( x ) = âˆ‘ n = 1 N â¢ â¢ A n â¢ T n â¡ ( x ) , T n (x), n=1, . . . , N denotes the spatial transmit sensitivity distributions of operative channels of the multi-channel RF transmit system, Î» is a weight parameter, A n , n=1, . . . , N denotes the complex amplitude values for the operative channels of the multi-channel RF transmit system, n is an index of an operative channel, and N is a total number of the operative channels.