Optimal pulse power measurement method and system for multinuclear simultaneous integrated magnetic resonance imaging

An optimal pulse power measurement method for multinuclear simultaneous integrated magnetic resonance imaging, comprising the following steps:

• (1) selectively simultaneously exciting, by combining shaped radiofrequency (RF) pulses and a slice selection gradient, multiple nuclides within a slice in a same pulse sequence repetition time (TR) of magnetic resonance imaging (MRI);
• and applying, in a slice encoding gradient channel, a frequency encoding gradient in a direction opposite to the slice selection gradient, and acquiring free induction decay (FID) signals of all the nuclides;
• alternatively, selectively exciting, by combining a shaped RF pulse and a slice selection gradient, one or more nuclides within a slice in advance;
• applying, in a slice encoding gradient channel, a frequency encoding gradient in a direction opposite to the slice selection gradient, and acquiring an FID signal of the nuclide excited in advance;
• selectively simultaneously exciting, by combining shaped RF pulses and the slice selection gradient, multiple other nuclides within the same slice;
• and applying, in the slice encoding gradient channel, the frequency encoding gradient in the direction opposite to the slice selection gradient, and acquiring FID signals of the multiple other nuclides;
• (2) simultaneously changing shaped RF pulse power values of all the nuclides for multiple times, and repeating the step (1) to acquire multiple FID signals corresponding to the shaped RF pulse power values of each nuclide;
• and
• (3) performing Fourier transform on the multiple FID signals of each nuclide in the step (2) to acquire a spectrum of the nuclide within the slice and extract an absolute spectrum of the spectrum;
• integrating the absolute spectrum of each nuclide, and marking an integral value as a signal intensity of the nuclide within the slice;
• and taking a shaped RF pulse power value corresponding to a maximum signal intensity of each nuclide as an optimal shaped RF pulse power corresponding to a current pulse sequence TR.