Temperature measurement method of permanent-magnet MRI system

Abstract

The invention relates to a temperature measurement method of a permanent-magnet MRI (Magnetic Resonance Imaging) system. The method comprises the steps that a flip angle value is calibrated; a coefficient between the spin lattice relaxation time and the temperature is calibrated; two groups of temperature measurement results by a proton resonance frequency method are obtained after data acquisition, data reconstruction and phase calibration; a group of temperature measurement results are obtained by a spin lattice relaxation time method; the temperature measurement results by the proton resonance frequency method and the temperature measurement results by the spin lattice relaxation time method are mixed and averaged; and a final temperature measurement result is obtained. The method is applied to a temperature measurement process of the permanent-magnet MRI system, and can effectively improve the temperature measurement accuracy and the temperature measurement stability.

Description

technical field [0001] The invention relates to a temperature measuring method of a permanent magnet MRI system. Background technique [0002] Magnetic resonance imager (hereinafter referred to as MRI) is one of the most widely used non-contact imaging medical equipment at present. It uses magnetic resonance phenomenon to obtain electromagnetic signals from the human body, and reconstructs human body information, which is mainly used in clinical human internal imaging diagnosis. [0003] MRI temperature measurement technology is a non-invasive temperature measurement technology, which is more and more widely used in the hyperthermia of tumors. The main methods include proton resonance frequency (hereinafter referred to as PRF), spin-lattice relaxation time (hereinafter referred to as T 1 , water molecule diffusion coefficient, MR spectrum, etc. The PRF method uses the relationship between temperature and image phase to measure the temperature of tissues, and is currently th...

AI Technical Summary

Problems solved by technology

while T 1 The temperature measurement method mainly relies on the amplitude information of the image for T 1 parameter estimates, but at T 1 The process of value measurement is affected by many factors, such as B 1 Field inhomogeneity and T 1 The dependence of values ​​on the properties of the tissue such that for T 1 The measurement of the value brings errors, which eventually leads to errors in temperature measurement

Although the superconducting system has the advantages of high imaging quality and fast speed, it has problems such as high production and maintenance costs and limited opening, while the permanent magnet MRI imaging system has good openness, which is convenient for doctors to perform interventional operations, and the production and maintenance costs Low, but the main magnetic field drift in the permanent magnet MRI system is serious, which makes the temperature measurement error of the PRF method larger

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