| Contrast-enhanced magnetic resonance angiography (MRA) is promising as a minimally invasive technique in treatment planning and follow-up of peripheral arterial disease. However, the standard technique is sensitive to the accurate timing of imaging relative to the contrast arrival and re-distribution, and dynamic information of contrast distribution is not available. To achieve time-resolved MRA, undersampling schemes with limited-view projections are investigated. Constrained reconstruction algorithms are developed to obtain both high spatial and temporal resolution with sufficient signal-to-noise ratio and limited artifacts. The AUCTION algorithm (Assignment and Update with CorrelaTION) is designed to reconstruct orthogonal biplane projections, and the HYPR algorithm (HighlY constrained backPRojection) is explored for reconstructing an arbitrary number of limited projections. Computer simulations, phantom and in-vivo studies are performed to demonstrate the effectiveness of the techniques. With limited-view projections, sub-millimeter spatial resolution and sub-second temporal resolution can be achieved over large fields-of-view for peripheral MRA. |
