Method for acquiring time-resolved MR images using continuous table motion
AssigneeMayo Foundation for Medical Education and Research
InventorsStephen J. Riederer, David G. Kruger, Ananth J. Madhuranthakam
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Abstract
MRA data is acquired from an extended field of view by translating the patient through the bore of the MRI system as three-dimensional MRA data sets are acquired and time-resolved images reconstructed. The leading edge of a contrast bolus can be tracked in these images and parameters such as bolus velocity and bolus arrival time can be calculated to provide functional information in addition to anatomical information. Temporal resolution is improved by undersampling peripheral k-space and sampling the center of k-space at a higher temporal rate.
Claims21
In a magnetic resonance imaging (MRI) system having a defined field of view (FOV), a method for producing a series of time-resolved images of a subject over an extended field of view (FOVtot) which is larger than the FOV, the steps comprising:
- a) moving the subject through the MRI system such that the extended field of view (FOVtot) passes through the defined field of view (FOV);
- b) acquiring three-dimensional image data while step a) is performed by repeatedly performing a three-dimensional pulse sequence with the MRI system to repeatedly sample three-dimensional k-space in accordance with a prescribed sampling pattern by stepping a phase encoding gradient through a prescribed series of values in a succession of phase encoding cycles, and in which the prescribed sampling pattern fully samples a central region of k-space and undersamples a peripheral region of k-space for each phase encoding cycle;
- c) adjusting the three-dimensional image data acquired in step b) to offset table motion during its acquisition;
- and
- d) reconstructing a series of time resolved, three-dimensional images from the adjusted three-dimensional image data acquired at successive times.
In a magnetic resonance imaging (MRI) system having a defined field of view (FOV), a method for producing an image of a subject over an extended field of view (FOVtot) which is larger than the FOV, the steps comprising:
- a) injecting a contrast agent into the subject;
- b) moving the subject through the MRI system such that the extended field of view (FOVtot) passes through the defined field of view (FOV);
- c) acquiring three-dimensional image data while step b) is performed by repeatedly performing a three-dimensional pulse sequence with the MRI system to repeatedly sample three-dimensional k-space in accordance with a prescribed sampling pattern, in which the prescribed sampling pattern fully samples a central region of k-space and undersamples a peripheral region of k-space;
- d) adjusting the three-dimensional image data acquired in step c) to offset table motion during its acquisition;
- e) reconstructing a series of time resolved, three-dimensional images from the adjusted three-dimensional image data acquired at successive times;
- f) examining the magnitude of pixels in the reconstructed series of time resolved, three-dimensional images to determine when contrast agent arrived therein;
- and
- g) reconstructing an image from adjusted three-dimensional image data that depicts the contrast enhanced vasculature of the subject throughout the extended field of view (FOVtot).
Dependencies are inferred from the claim text.