Online spatiotemporally constrained reconstruction for real-time interactive MRI

Motivation: Real-time interactive MRI is extremely useful during localization of moving structures and guidance of interventional procedures. View-sharing is currently used but presents an unfavorable tradeoff between aliasing artifacts and temporal resolution. Goal(s): To develop a low latency reconstruction that provides the spatial and temporal fidelity comparable to offline compressed sensing reconstruction. Approach: We implement online spatiotemporally constrained reconstruction (STCR) using a computationally efficient Augmented Lagrangian solution that terminates before the acquisition of the next frame. Results: Online STCR removes aliasing artifacts and has superior temporal definition compared to view-sharing and comparable to offline STCR. Impact: We demonstrate low-latency reconstruction for 2D real-time MRI with spatial resolution 1.5/2.25mm2, temporal resolution 25.2/31.8ms, and FOV 240×240/320×320mm, improving visual recognition of rapidly moving boundaries.