Subdivided High-resolution Angiography with Reconstruction of Exchanged Data (SHARED)

Motivation: Infeasible breath-hold durations for high-resolution MRA necessitate navigator-gating, however, saturation artefacts, residual motion and poor navigator-efficiency impair acquisitions. Furthermore, multiple dedicated localizers increase total exam time. Goal(s): To subdivide a high-resolution MRA in multiple breath-holds and share raw-data during reconstruction. To utilize data from one breath-hold for automated view planning. Approach: We subdivided the sampling pattern of a navigator-gated sequence into concentric rings, each acquired in one breath-hold. Previously acquired rings were jointly reconstructed. Measurements were performed on 5 volunteers. Results: Image quality and sharpness were comparable to navigator-gated MRA. A localization network successfully identified cardiac view planes using data from one breath-hold. Impact: Multiple breath-held scans with predictable timings yield high-resolution angiography images. The first scan is used for automatic view planning and, unlike dedicated localizers, contributes to diagnostic images. Online reconstruction after each breath-hold enables increasing spatial resolution with every breath-hold.