International Journal on Magnetic Particle Imaging
Vol 6 No 1 (2020): Int J Mag Part Imag

Accepted Manuscripts for Future Issue

Non-ideal Selection Field Induced Artifacts in X-Space MPI

Main Article Content

Ecrin Yagiz (Bilkent University), Ahmet R. Cagil (Bilkent University), Emine Ulku Saritas (Bilkent University)


In magnetic particle imaging (MPI), the selection field deviates from its ideal linearity in regions away from the center of the scanner. This work demonstrates that unaccounted non-linearity of the selection field causes warping in the image reconstructed with a basic x-space approach. We also show that unwarping algorithms can be applied to effectively address this issue, once the displacement map acting on the reconstructed image is determined. The unwarped image accurately represents the locations of nanoparticles, albeit with a resolution loss in regions away from the center of the scanner due to the degradation in selection field gradients.
Int. J. Mag. Part. Imag., 2020, Article ID: 2006001, DOI: 10.18416/IJMPI.2020.2006001

Article Details


[1] B. Gleich and J. Weizenecker. Tomographic imaging using the nonlinear response of magnetic particles. Nature, 435(7046):1214–1217, 2005, doi:10.1038/nature03808.

[2] P. W. Goodwill and S. M. Conolly. The X-Space Formulation of the Magnetic Particle Imaging Process: 1-D Signal, Resolution, Bandwidth, SNR, SAR, and Magnetostimulation. IEEE Transactions on Medical Imaging, 29(11):1851–1859, 2010, doi:10.1109/TMI.2010.2052284.

[3] P.W. Goodwill and S. M. Conolly. Multidimensional X-Space Magnetic Particle Imaging. IEEE Transactions on Medical Imaging, 30(9):1581–1590, 2011, doi:10.1109/TMI.2011.2125982.

[4] P. Vogel, M. A. Rückert, P. Klauer, W. H. Kullmann, P. M. Jakob, and V. C. Behr. Traveling Wave Magnetic Particle Imaging. IEEE Transactions on Medical Imaging, 33(2):400–407, 2014, doi:10.1109/TMI.2013.2285472.

[5] J. Rahmer, J.Weizenecker, B. Gleich, and J. Borgert. Signal encoding in magnetic particle imaging: properties of the system function. BMC Medical Imaging, 9:4, 2009, doi:10.1186/1471-2342-9-4.

[6] F. Roméo and D. I. Hoult. Magnet field profiling: Analysis and correcting coil design. Magnetic Resonance in Medicine, 1(1):44–65, 1984, doi:10.1002/mrm.1910010107.

[7] A. Weber, F.Werner, J.Weizenecker, T. M. Buzug, and T. Knopp. Artifact free reconstruction with the system matrix approach by overscanning the field-free-point trajectory in magnetic particle imaging. Physics in Medicine and Biology, 61(2):475–487, 2016, doi:10.1088/0031-9155/61/2/475.

[8] J. Kybic, P. Thevenaz, A. Nirkko, and M. Unser. Unwarping of unidirectionally distorted EPI images. IEEE Transactions on Medical Imaging, 19(2):80–93, 2000, doi:10.1109/42.836368.

[9] S. J. Doran, L. Charles-Edwards, S. A. Reinsberg, and M. O. Leach. A complete distortion correction for MR images: I. Gradient warp correction. Physics in Medicine and Biology, 50(7):1343–1361, 2005, doi:10.1088/0031-9155/50/7/001.

[10] H. Medimagh, P. Weissert, G. Bringout, K. Bente, M. Weber, K. Gräfe, A. Cordes, and M. Buzug Thorsten. Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields. Current Directions in Biomedical Engineering, 1(1):245–248, 2015, doi:10.1515/cdbme-2015-0061.

[11] M. Utkur, Y.Muslu, and E. U. Saritas, A 4.8 T/m Magnetic Particle Imaging Scanner Design and Construction, in 2017 21st National Biomedical Engineering Meeting (BIYOMUT), i–iv, IEEE, 2017. doi:10.1109/BIYOMUT.2017.8479214.

[12] Y.Muslu, M. Utkur, O. B. Demirel, and E. U. Saritas. Calibration-Free Relaxation-Based Multi-Color Magnetic Particle Imaging. IEEE Transactions on Medical Imaging, 37(8):1920–1931, 2018, doi:10.1109/TMI.2018.2818261.

[13] K. Lu, P. W. Goodwill, E. U. Saritas, B. Zheng, and S. M. Conolly. Linearity and Shift Invariance for Quantitative Magnetic Particle Imaging. IEEE Transactions on Medical Imaging, 32(9):1565–1575, 2013, doi:10.1109/TMI.2013.2257177.

[14] E. Bozkurt and E. U. Saritas. Signal-to-noise ratio optimized image reconstruction technique for magnetic particle imaging. Journal of the Faculty of Engineering and Architecture of Gazi University, 32(3):999–1013, 2017, doi:10.17341/gazimmfd.337864.

[15] R. M. Ferguson, A. P. Khandhar, S. J. Kemp, H. Arami, E. U. Saritas, L. R. Croft, J. Konkle, P. W. Goodwill, A. Halkola, J. Rahmer, J. Borgert, S. M. Conolly, and K. M. Krishnan. Magnetic Particle ImagingWith Tailored Iron Oxide Nanoparticle Tracers. IEEE Transactions on Medical Imaging, 34(5):1077–1084, 2015, doi:10.1109/TMI.2014.2375065.

[16] T. Knopp and T. M. Buzug, Magnetic Particle Imaging: An Introduction to Imaging Principles and Scanner Instrumentation. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012, doi:10.1007/978-3-642-04199-0.

[17] S. I. Babic and C. Akyel. Improvement in the analytical calculation of the magnetic field produced by permanent magnet rings. Progress In Electromagnetics Research C, 5:71–82, 2008.

[18] P. W. Goodwill, J. J. Konkle, B. Zheng, E. U. Saritas, and S. T. Conolly. Projection X-Space Magnetic Particle Imaging. IEEE Transactions on Medical Imaging, 31(5):1076–1085, 2012, doi:10.1109/TMI.2012.2185247.

[19] A. A. Ozaslan, A. Alacaoglu, O. B. Demirel, T. Çukur, and E. U. Saritas. Fully automated gridding reconstruction for non-Cartesian x-space magnetic particle imaging. Physics in Medicine & Biology, 64(16):165018, 2019, doi:10.1088/1361-6560/ab3525.

[20] P. Szwargulski, N. Gdaniec, M. Graeser, M.Möddel, F. Griese, K. M. Krishnan, T. M. Buzug, and T. Knopp. Moving table magnetic particle imaging: a stepwise approach preserving high spatiotemporal resolution. Journal of Medical Imaging, 5(4):1, 2018, doi:10.1117/1.JMI.5.4.046002.

[21] P. Vogel, T. Kampf, M. A. Rückert, and V. C. Behr. Flexible and Dynamic Patch Reconstruction for Traveling Wave Magnetic Particle Imaging. International Journal onMagnetic Particle Imaging, 2(2), 2016, doi:10.18416/IJMPI.2016.1611001.

[22] K.Murase, N. Banura, A.Mimura, and K. Nishimoto. Simple and practical method for correcting the inhomogeneous sensitivity of a receiving coil in magnetic particle imaging. Japanese Journal of Applied Physics, 54(3):038001, 2015, doi:10.7567/JJAP.54.038001.