Projection Reconstruction (PR) Imaging Process. An illustration of a 1D projection is shown. In our PR Magnetic Particle Imaging (MPI) system, we acquire 2D projection images at multiple rotation angles to reconstruct 3D images.
Projection Reconstruction MPI System Photo. The system includes a permanent magnet Field Free Line (FFL) selection gradient, inductive drive and focus field electromagnets, a solenoidal receive coil, and a motor driven rotary table.
Helical Imaging Phantom. Tubing injected with Resovist is wrapped in a helical pattern around an acrylic cylinder. Phantom size: 2.8 cm x 2.8 cm x 8 cm.
Experimental PR Maximum Intensity Projection Image. We acquired multiple projection images with our PR MPI system and reconstructed the 3D volume via filtered backprojection. (click on image to see rotated view)
Konkle, J., Goodwill, P., Carrasco-Zevallos, O., & Conolly, S. (2012). Projection Reconstruction Magnetic Particle Imaging. IEEE transactions on medical imaging, 1–1. doi:10.1109/TMI.2012.2227121 link
Abstract: We acquire the first experimental 3D tomographic images with Magnetic Particle Imaging (MPI) using projection reconstruction methodology, which is similar to algorithms employed in X-ray computed tomography. The primary advantage of projection reconstruction methods is an order of magnitude increase in SNR due to averaging. We first derive the point spread function, resolution, number of projections required, and the SNR gain in projection reconstruction MPI. We then design and construct the first scanner capable of gathering the necessary data for non-aliased projection reconstruction and experimentally verify our mathematical predictions. We demonstrate that filtered backprojection in MPI is experimentally feasible and illustrate the SNR and resolution improvements with projection reconstruction. Finally, we show that MPI is capable of producing three dimensional imaging volumes in both phantoms and post-mortem mice.
J. Konkle (presentation), P. Goodwill, O. Carrasco-zevallos, and S.
Conolly, “Experimental 3D X-Space Magnetic Particle Imaging Using
Projection Reconstruction,” in Magnetic Particle Imaging: A Novel SPIO
Nanoparticle Imaging Technique, 2012, pp. 243–247. link