Automatic frequency tuning for a magnetic resonance apparatus

摘要

A method (100) of automatically tuning a radio frequency transmitter (24) and receiver (38) in a magnetic resonance imaging apparatus to an optimum frequency includes generating and acquiring (104) a magnetic resonance signal. The magnetic resonance signal is transformed to the frequency domain and spectral magnitude of the signal is computed (106). A centre of gravity interpolation is performed (110) on the spectral magnitude to obtain a desired frequency sampling. A model function is generated based upon a strength of a main magnetic field which has peaks separated by the same separation as that for fat and water signals. The spectral magnitude is correlated (112) with the model function and a peak having the greatest magnitude is located therefrom. The location of a species peak along the spectral magnitude is estimated (114) from empirically derived information, the strength of the main magnetic field and the location of the correlation peak. A region of the spectral magnitude to be examined is defined (116) from empirically derived information, and a peak within this region is located (118) which is nearest the estimated location. Ultimately, the frequency of the radio frequency transmitter and receiver is set (122) to align with the peak located within the region that is nearest the estimated location. <IMAGE>