Perturbation method for magnetic field calculations of nonconductive objects

Mark Jenkinson, James L. Wilson, Peter Jezzard

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)


Inhomogeneous magnetic fields produce artifacts in MR images including signal dropout and spatial distortion. A novel perturbative method for calculating the magnetic field to first order (error is second order) within and around nonconducting objects is presented. The perturbation parameter is the susceptibility difference between the object and its surroundings (for example, ∼10 ppm in the case of brain tissue and air). This method is advantageous as it is sufficiently accurate for most purposes, can be implemented as a simple convolution with a voxel-based object model, and is linear. Furthermore, the method is simple to use and can quickly calculate the field for any orientation of an object using a set of precalculated basis images.

Original languageEnglish
Pages (from-to)471-477
Number of pages7
JournalMagnetic Resonance in Medicine
Issue number3
Publication statusPublished or Issued - Sep 2004
Externally publishedYes


  • Distortion
  • Field calculation
  • Simulation
  • Susceptibility

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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