MRI geometric distortion: A simple approach to correcting the effects of non‐linear gradient fields

We present a method to correct intensity variations and voxel shifts caused by non‐linear gradient fields in magnetic resonance images. The principal sources of distortion are briefly discussed, as well as the methods of correction currently in use. The implication of the gradient field non‐linearities on the signal equations are described in a detailed way for the case of two‐ and three‐dimensional Fourier imaging. A model of these non‐linearities, derived from the geometry of the gradient coils, is proposed and then applied in post‐processing to correct any images regardless of the acquisition sequence. Initial position errors, as large as 4 mm (i.e., four voxels of 1 × 1 × 1.4 mm3 ) before correction, are reduced to less than the voxel sizes after correction. J. Magn. Reson. Imaging 1999;9:821–831. © 1999 Wiley‐Liss, Inc.

[1]  W. Eric L. Grimson,et al.  Adaptive Segmentation of MRI Data , 1995, CVRMed.

[2]  D. Kondziolka,et al.  Patient outcomes after stereotactic radiosurgery for "operable" arteriovenous malformations. , 1994, Neurosurgery.

[3]  B. Dawant,et al.  Effect of geometrical distortion correction in MR on image registration accuracy. , 1996, Journal of computer assisted tomography.

[4]  A. Lent,et al.  An introduction to NMR imaging: From the Bloch equation to the imaging equation , 1983, Proceedings of the IEEE.

[5]  L Walton,et al.  A phantom study to assess the accuracy of stereotactic localization, using T1-weighted magnetic resonance imaging with the Leksell stereotactic system. , 1996, Neurosurgery.

[6]  J. Schenck.  The role of magnetic susceptibility in magnetic resonance imaging: MRI magnetic compatibility of the first and second kinds. , 1996, Medical physics.

[7]  P. Macdonald,et al.  Empirical compensation function for eddy current effects in pulsed field gradient nuclear magnetic resonance experiments. , 1995, Solid state nuclear magnetic resonance.

[8]  P Schmalbrock,et al.  Water and fat MR imaging with chemical shift selective 3D steady state methods , 1994, Magnetic resonance in medicine.

[9]  F. A. Seiler,et al.  Numerical Recipes in C: The Art of Scientific Computing , 1989 .

[10]  V Sturm,et al.  Correction of spatial distortion in MR imaging: a prerequisite for accurate stereotaxy. , 1987, Journal of computer assisted tomography.

[11]  M A Moerland,et al.  Analysis and correction of geometric distortions in 1.5 T magnetic resonance images for use in radiotherapy treatment planning. , 1995, Physics in medicine and biology.

[12]  E M Haacke,et al.  Fast MR imaging: techniques and clinical applications. , 1990, AJR. American journal of roentgenology.

[13]  Peter A. Bandettini,et al.  Effects of biophysical and physiologic parameters on brain activation‐induced R2* and R2 changes: Simulations using a deterministic diffusion model , 1995, Int. J. Imaging Syst. Technol..

[14]  G. Glover,et al.  Characterization of spatial distortion in magnetic resonance imaging and its implications for stereotactic surgery. , 1994, Neurosurgery.

[15]  G. Marchal,et al.  On the problem of geometric distortion in magnetic resonance images for stereotactic neurosurgery. , 1994, Magnetic resonance imaging.

[16]  S Napel,et al.  Quantifying MRI geometric distortion in tissue , 1994, Magnetic resonance in medicine.

[17]  W. Eric L. Grimson,et al.  Adaptive Segmentation of MRI Data , 1995, CVRMed.

[18]  D. G. Hughes,et al.  Intensity artifacts in MRI caused by gradient switching in an animal‐size NMR magnet , 1992, Magnetic resonance in medicine.

[19]  S. Posse,et al.  Direct imaging of magnetic field gradients by group spin‐echoselection , 1992, Magnetic resonance in medicine.