Patent ID: 7215124
Filing Date: 2007-05-08
Classification: G01R

Abstract:
1. A method for producing an image of an object located in the field of view of an MR imaging system, which image depicts the object at a selected one or more of a plurality of different spatial positions during cyclical movement of the object, the steps comprising: (a) applying a position sensing device to the object, said device providing signals to said MR imaging system at the instant when the object passes through said different spatial positions during its cyclical movement; (b) repeatedly moving the object over a given cycle of movement, and recording with reference to a system clock the specific time that the object was at each of the different spatial positions during successive cycles of its movement; (c) simultaneously with the repeated movement of the object, repeatedly executing elements of an MR pulse sequence so that the MR imaging system will acquire for each element of the MR pulse sequence a subset of MR data, said execution being asynchronous with respect to said object movement, and said MR pulse sequence including at least one position encoding gradient pulse which is caused to have all values required in order to acquire at least the minimum amount of MR data sets needed to reconstruct an image; (d) retrospectively selecting the subset of MR data acquired during the execution of each MR pulse sequence element which occurred at the same time or nearly the same time that the object passed through a given one of the plurality of different spatial positions in successive cycles of said object movement, said time being indicated by the signal provided by the position sensing device; and (e) reconstructing an image of the object at the given one of the different spatial positions using the MR data retrospectively selected in step (d).