Towards robot-assisted magnetic particle imaging for mobile point-of-care (neuro)vascular applications.

Rapid diagnosis, timely treatment, and continuous monitoring are essential for improving outcomes in neurovascular diseases (time=brain). Such point-of-care applications, however, require imaging to be conducted in dynamic and often confined spaces. While magnetic particle imaging (MPI) shows preclinical promise for fast (neuro)vascular imaging, it relies on complex and restricted imaging gantries. Here, we present a unique gantry-free robot-assisted MPI strategy (Robotic MPI) that is 'portable'. Using permanent magnets, Hall sensors and correction coils, we developed a single-sided detector with a detection threshold of ~ 5 µg iron-containing contrast agent at the detector surface. Robot-assisted positioning and pose tracking, combined with a dedicated maximum likelihood expectation-maximization-based reconstruction algorithm, translates detector signals into tomographic images with a spatial resolvability of 7 mm (visually evaluated at an imaging depth of ~ 5 mm). Surface imaging (SI) provided anatomical reference, delivering hybrid MPI/SI scans. Robotic-MPI's ability to visualize 3D (neuro)vasculature in a phantom model, highlights the system's potential for next-generation, portable vascular imaging solutions.