Relaxation in x-space Magnetic Particle Imaging

  • Laura R. CroftEmail author
  • Patrick Goodwill
  • Matt Ferguson
  • Kannan Krishnan
  • Steven Conolly
Part of the Springer Proceedings in Physics book series (SPPHY, volume 140)


Magnetic particle imaging (MPI) is an emerging medical imaging modality capable of high-sensitivity images with unprecedented contrast and without ionizing radiation [1]. Our laboratory previously developed the x-space theory for MPI, which describes MPI as a scanning process in the spatial domain [2,3]. X-space MPI is particularly critical as it permits real-time image reconstruction, orders of magnitude faster than the traditional harmonic space system matrix reconstruction methods. The x-space theory was derived assuming adiabatic and instantaneous alignment of ultra-small superparamagnetic iron oxide nanoparticles (USPIOs) with the applied magnetic field. However, in reality the magnetization lags behind the applied field due to relaxation. Here, we include relaxation in the x-space MPI theory and show that real-time reconstruction is still feasible even with relaxation effects.


Chronic Kidney Disease Point Spread Function Relaxation Effect Scanning Direction Relaxation Time Constant 
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Copyright information

© Springer-Verlag GmbH Berlin Heidelberg 2012

Authors and Affiliations

  • Laura R. Croft
    • 1
    Email author
  • Patrick Goodwill
    • 1
  • Matt Ferguson
    • 3
  • Kannan Krishnan
    • 3
  • Steven Conolly
    • 1
    • 2
  1. 1.Departments of BioengineeringUniversity of California, BerkeleyBerkeleyUSA
  2. 2.EECSUniversity of California, BerkeleyBerkeleyUSA
  3. 3.Department of Materials Science & EngineeringUniversity of WashingtonSeattleUSA

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