METHOD AND APPARATUS FOR PERFORMING GUIDED AND FLEXIBLE SELF-NAVIGATED STRUCTURAL MRI FOR MOTION COMPENSATION

摘要

A method and a magnetic resonance imaging apparatus provide subject/object motion detection and correction during a MRI scan. The method includes generating via a magnetic resonance scanner a magnetic field gradient and a radio-frequency signal for the MRI scan. The radio-frequency signal contains a successive repetition of pulse sequences, each pulse sequence starting with a radio-frequency excitation pulse. A time between two successive radio-frequency excitation pulses are defined as a repetition time. Detecting, from a readout signal emitted in response to the pulse sequence, time-points in which motion has occurred. Interleaves are automatically created. A sampling of the k-space is performed by arranging k-space MRI readout signals acquired over each repetition time of the pulse sequence into several groups of interleaves of uniform k-space sampling reconstructing separately each subset of interleaves for obtaining low resolution MR images.

主权项

1. A computer-implemented method for subject/object motion detection and correction during a magnetic resonance imaging (MRI) scan, which comprises the steps of:
generating, via a magnetic resonance scanner, a magnetic field gradient and a radio-frequency signal for the MRI scan, the radio-frequency signal having a successive repetition of at least one pulse sequence, the pulse sequence starting with a radio-frequency excitation pulse, a time between two successive radio-frequency excitation pulses being defined as a repetition time; detecting, from a readout signal emitted in response to the pulse sequence, time-points in which motion has occurred, the detecting being realized via a motion detection technique configured for detecting occurrences of subject/object motion in dependence on a time during the MRI scan; automatically creating motion-free interleaves, a sampling of k-space is performed by disposing k-space readout signals acquired over the repetition time of the pulse sequence into several groups of interleaves characterized by a uniform sampling of the k-space; reconstructing separately each subset of interleaves for obtaining low resolution MR images; using the low resolution images for determining motion parameters via a computational technique and by registration to a reference image; and using the motion parameters to improve a quality of images obtained during the MRI scan.