Abstract: A method for producing an MRI image, including acquiring multiple intermediate images of a subject under analysis using alternating preparation phases; synchronizing the acquisitions with a physiological variable of the subject; forming a first and a second set of intermediate images resulting from distinct preparation phases; assigning to each intermediate image a timestamp based on the time elapsed between the acquisition time of the current intermediate image and the previous intermediate image; matching intermediate images of the first set with respective intermediate images of the second set based on their timestamps being equal within a tolerance margin; producing a first candidate output image based on a function of the matched intermediate images; increasing the tolerance margin by an increment; reiterating the matching step to produce a further candidate output image; and selecting as an output image a candidate image based on the signal-to-noise ratio of the candidate image.

Abstract: The invention relates to a process for the production of magnetic resonance images of a body for which an image is required, characterized in that it comprises the following steps: place at least the body for which an image is required in a stationary magnetic field, inject a blood tracer containing at least one hyperpolarized rare gas into the blood circulatory system for at least the body for which an image is required, apply radio frequency pulses and magnetic field gradients to the body for which an image is required to excite nuclear magnetization of the hyperpolarized rare gas, acquire nuclear magnetic resonance signals in the k space in the form of N acquisitions each passing through the centre of the k space, and, starting from nuclear magnetic resonance signals, reconstruct images, replacing at least one acquisition of a k space for each image by an acquisition of the next k space.