Motion Artifact Suppression in Breath Hold 3D Contrast Enhanced Magnetic Resonance Angiography using ECG Ordering

Vascular pulsation and cardiac motion compromise image quality in contrast enhanced magnetic resonance angiography (CE-MRA) in the thorax, resulting in blurring and ghosting artifacts. The use of ECG gating has been proposed in the past to mitigate these artifacts but previous methods suffered from increased scanner time because only a fraction of the cardiac cycle was used for image acquisition and from loss of the study when gating failed. We propose a robust ECG ordering of k-space for breath hold CE-MRA that acquires the central part of k-space in a motion-free portion of diastole and fills in from the periphery of k-space at all other times. To make maximal use of the contrast enhancement, data is acquired continuously even when the ECG signal is lost. The proposed sequence is shown to allow thoracic and pulmonary MRA with a higher resolution when compared to the conventional gated sequence