Feasibility of interactive magnetic resonance imaging of moving anatomy for clinical practice

Summary: Background: Real-time magnetic resonance imaging (MRI) imaging with real-time reconstruction has been available for some time. The technique acquires and presents the MRI images to the operator the instant they are acquired. However, besides guiding purposes, like catheter tracking and placement of electrodes during neurosurgery, the diagnostic value of this method is relatively unexplored. Purpose: To test an interactive slice-positioning system with respect to real-time MRI reconstruction for imaging of moving anatomical structures on two different scanner brands by using inexpensive computer hardware. Materials and methods: The MRI data were sampled using two acquisition schemes: a Cartesian sampling scheme and a radial sampling scheme based on the golden ratio. Four anatomical targets, which exhibit non-periodic movement, were identified and imaged: movement of the gastric ventricle emptying, movement of the small bowels, the articulators of a professional singer and of a 20-week old fetus. Results: Informative anatomical images were obtained in different settings of moving targets. The implemented real-time system acquired, reconstructed and displayed MRI images in real time with a high frame rate using inexpensive computer hardware on two standard 1.5 T clinical MRI scanners. Conclusion: Our approach verified that when imaging selected moving anatomical targets, with no a priori knowledge of the movement, interactive slice positioning using real-time reconstruction may be a feasible approach for finding the optimal slice position in cases in which a standard 3D volumetric scan is impeded by movement. Future studies are needed to explore its full potential.