METHOD OF MAKING MAP OF RF TRANSMISSION AND RECEPTION MAGNETIC FIELD OF NMR DEVICE

PURPOSE: To easily detect and evaluate the heterogeneity of the RF receiving magnetic field of an NMR device coupled to a receiving array by generating the heterogeneity as a magnetic field map shown with the intensity of data elements. CONSTITUTION: For the measurement of the heterogeneity of the RF transmission magnetic field and RF receiving magnetic field of coils 138A and 138B, scan parameters selected from CPU are set and outputted as a frequency from a frequency synthesizer 200 via a signal line 103. Then, the output frequency is modulated with a modulator 202 under the application of an RF excitation signal 203 and a PCM signal 204, thereby generating RF transmission magnetic field from the coil 138A via a transmission signal attenuation circuit 206 and an amplifier 123. Then, the RF receiving magnetic field is detected with the coil 138B, amplified with a receiver 207 and demodulated with a right angle wave detector 209, using an output frequency from the frequency synthesizer 210 and sent to the CPU via an A/D converter 215, thereby preparing a magnetic field map. According to this construction, the heterogeneity of the transmission RF excitation magnetic field and RF receiving magnetic field can be easily detected and evaluated.