Patent ID: 8334695
Filing Date: 2012-12-18
Classification: G01R

Abstract:
1. A method for producing an image of an object located in the field of view of a magnetic resonance (MR) imaging system, said image being sensitive to molecular diffusional motion in one or more spatial directions, and said image being substantially insensitive to mechanical vibration of the MR imaging, comprising the steps of: (a) making a list of all the desired combinations of diffusion-encoding direction, diffusion-encoding amplitudes, and slice positions, said list including the desired unencoded reference acquisitions; (b) transferring one element of list (a) associated with the first desired slice position to the first position of a primary reordered list, and then transferring another element of list (a) associated with the second desired slice position to second position of the reordered list, and continuing until one element is transferred for each of the spatially distinct desired slice positions of the slice block, these elements chosen to randomize or avoid repetitious patterns of the diffusion-encoding directions and amplitudes; (c) transferring additional elements of list (a) to the reordered list, repeating the same slice order as in (b), and again seeking to avoid repetition patterns of the diffusion encoding, this process continuing until all of the elements of list (a) have been transferred to the reordered list; (d) repeating steps (a) through (c) to create one or more distinct secondary reordered lists; (e) beginning with the first element of the primary reordered list, acquiring single-shot images using the slice position, the diffusion-encoding direction and the diffusion-encoding amplitude contained in said element, and continuing, in order, through the elements of said list, acquiring one image for each element; (f) reconstructing and displaying the images as in existing pulse sequences; and (g) reacquiring the scan, if needed, with one of the alternate pulse lists from step (d) if analysis of the resulting data shows unacceptable levels of patient table vibration or patient motion or vibration-induced image artifact.