Respiratory displacement and velocity measurement using navigator MRI echo signals

摘要

Navigator signals (348) are acquired during a cardiac gated MRI scan to measure the position and velocity components of respiratory motion. Acquired cardiac image views are discarded and/or corrected based on the measurement of the positional and velocity components of respiratory motion to reduce motion artifacts. In one embodiment the navigator pulse sequence includes velocity encoding gradient (340, 356), and in a second embodiment, velocity is determined by measuring the change in diaphragm position between successive navigator pulse sequences (324, 236).