Cascaded container and method for pre-polarizing magnetic resonance contrast agent

Abstract

The invention discloses a cascaded container for pre-polarizing a magnetic resonance contrast agent. The cascaded container comprises a heat preserving box, a first container and a second container, wherein the first container and the second container are arranged in the heat preserving box; porous pipelines are respectively arranged outside the first container and the second container; a channel and an alkali metal filling pipeline are respectively arranged on the first container and the second container; platinum resistors are respectively arranged in the first container and the second container; a first light window and a second light window are arranged on the heat preserving box; three groups of Helmholtz coils are arranged outside the heat preserving box. The invention also discloses a method for pre-polarizing the magnetic resonance contrast agent through the cascaded container. Laser pre-polarization is realized by performing multiple kinds of pretreatment on the magnetic resonance contrast agent through the cascaded container. The cascaded container is compact and simple in structure, easy to replace and convenient to use; meanwhile, the power and the contour of a laser can be fully utilized, so that the laser pumping efficiency of pre-polarization of the magnetic resonance contrast agent is effectively improved.

Description

technical field [0001] The present invention relates to the field of polarization of atoms and nuclei, and more specifically to a prepolarization method based on the premixing of flowing working gas and alkali metal atom vapor, increasing the interaction between laser and alkali metal atoms and the spin exchange collision transfer region, and provides a Cascaded containers for prepolarization, particularly suitable for laser prepolarization of magnetic resonance contrast agents. Background technique [0002] Prepolarize MR contrast agents using optically pumped spin-exchange techniques (e.g. 3 He, 129 Xe) is a very effective method, which can improve the detection sensitivity of contrast agents by ∼100,000 times, and they may become a new tool for visualizing lung and brain functions or clinical early disease diagnosis. [0003] In laser prepolarization, the establishment of the nuclear spin polarization of the lung and brain MRI contrast agents depends on the working envi...

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Problems solved by technology

[0004] 1) The working gas at room temperature (for example: Xe+He+N2 mixed gas) flows into the optical pumping container, which reduces the temperature of the optical pumping container, which leads to a drop in the temperature of the alkali metal and affects the working density of the alkali metal atom vapor;

[0005] 2) After the working gas at high pressure (for example: 5atm) flows into the optical pumping container, eddy currents will be generated, which makes the distribution of the working gas in the optical pumping container not so uniform;

[0008] 5) If the working gas is not pre-treated, it will contain a small amount of impurities such as water and oxygen. There is a potential danger of contamination of the alkali metal in the optical pumping container, such as oxidation, and usually the oxide will block the optical pumping The inlet or outlet of the container, resulting in reduced efficiency of laser prepolarized magnetic resonance contrast agents or reduced working life of optically pumped containers, making it necessary to frequently fill new alkali metals or replace new containers

However, for specific implementation and popularization and application, periodic maintenance of nearly 1000 mm long spiral prepolarization device components - cleaning the inner wall of the spiral tube, loading alkali metal Rb, etc. are extremely troublesome things

[0016] Obviously, these methods and techniques still have some shortcomings

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