Abstract
Magnetic resonance navigation (MRN) is an emerging research technique in recent years. The micro/nano robots existing in vessels can be driven by magnetic gradients given by MR scanner. As a non-invasive vascular imaging technique, Magnetic resonance angiography (MRA) is able to provide a vascular network of an anatomy without injection of contrast agent. In order to automatically guide and drive micro/nano robots to target in vascular network, a navigation strategy is desired. In this paper, a novel path planning algorithm based on A* search is proposed. The MRA image is preliminarily processed to extract major vessels. Then, pixel-based A* search algorithm identifies the shortest path between start point and target without human supervision. Experimental results on both of simulation image and MRA image demonstrate that the proposed method is able to accomplish path planning automatically in MRA image. That path can guide the injected micro/nano robots to navigate in the blood vessels.