Journal ArticleDOI
Reconstructing NMR images under magnetic fields with large inhomogeneities
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TLDR
In this article, a novel technique for reconstructing accurate NMR images from projections under inhomogeneous main magnetic field was presented for two-and three-dimensional imagings, and the mathematical basis and the point-spread functions of such a curvilinear reconstruction for 2D and 3D imagings were fully described.Abstract:
A novel technique is presented for reconstructing accurate NMR images from projections under inhomogeneous main magnetic field. The mathematical basis and the point-spread functions of such a curvilinear reconstruction for two- and three-dimensional imagings are fully described. The proper use and the effectiveness of this technique are demonstrated by computer simulations. The promising results presented could strongly influence practices in the design, manufacture and use of the main magnet for NMR imaging by the projections method.read more
Citations
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Journal ArticleDOI
A technique for accurate magnetic resonance imaging in the presence of field inhomogeneities
Hing-Chiu Chang,J.M. Fitzpatrick +1 more
TL;DR: The improved accuracy in geometry and intensity may improve reliability of stereotactic surgery, may enhance the feasibility of both clinical and industrial imaging via external fields, and may increase the resolution of microscopic imaging.
Journal ArticleDOI
A homogeneity correction method for magnetic resonance imaging with time-varying gradients
TL;DR: A reconstruction and homogeneity correction method to correct for the zeroth order effects of inhomogeneous using prior knowledge of the inhomogeneity is introduced.
Journal ArticleDOI
MR susceptibility misregistration correction
TL;DR: A new in vivo method to correct the nonlinear, object-shape-dependent and material-dependent spatial distortion in magnetic resonance (MR) images caused by magnetic susceptibility variations is presented.
Journal ArticleDOI
Spatial Precision in Magnetic Resonance Imaging-Guided Radiation Therapy: The Role of Geometric Distortion
Joseph Weygand,Joseph Weygand,Clifton D. Fuller,Geoffrey Ibbott,Geoffrey Ibbott,Abdallah S.R. Mohamed,Yao Ding,Jinzhong Yang,Jinzhong Yang,Ken Pin Hwang,Jihong Wang,Jihong Wang +11 more
TL;DR: The evidence indicates that geometric distortion reduces the spatial integrity of MRI-based radiation treatment planning and likely diminishes the efficacy of MRIgRT, and better phantom measurement techniques and more effective distortion correction algorithms are needed to achieve the desired spatial precision.
Patent
Method for correcting image distortion due to gradient nonuniformity
Gary H. Glover,Norbert J. Pelc +1 more
TL;DR: In this paper, a method for correcting image distortion arising from magnetic field gradient nonuniformity is proposed, in accordance with which the gradient non-uniformness is modeled, the expected distortion in the image calculated, and a geometric correction applied to the distorted image.
References
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Journal ArticleDOI
Image formation by nuclear magnetic resonance: The sensitive‐point method
TL;DR: In this paper, an image formation method, using nuclear magnetic resonance techniques, has been developed which provides direct and detailed information on the interior details of heterogeneous samples, by directly plotting the phase-detected resonance signal on a xy plotter as the limited region of spectrometer sensitivity is scanned through the sample.
Journal ArticleDOI
NMR imaging: image recovery under magnetic fields with large non-uniformities.
TL;DR: In the field of NMR imaging using selective excitation techniques, a procedure is described whereby image information can be recovered with acceptable fidelity in the presence of large magnetic field non-uniformities.
Journal ArticleDOI
A gradient control device for complete three-dimensional nuclear magnetic resonance zeugmatographic imaging
Ching-Ming Lai,P C Lauterbur +1 more
TL;DR: In this article, a microprocessor-based device for controlling magnetic field gradients in 3D dimensions is described, including the design logic, the interface to a minicomputer and a nuclear magnetic resonance spectrometer.
Journal ArticleDOI
True three-dimensional nuclear magnetic resonance imaging by Fourier reconstruction zeugmatography
TL;DR: In this paper, Fourier reconstruction zeugmatography (FRZM) was introduced for obtaining three-dimensional nuclear magnetic resonance images from transient NMR signals using a Fourier transform technique.
Journal ArticleDOI
Automatic correction of nuclear magnetic resonance zeugmatographic projections
Ching-Ming Lai,P C Lauterbur +1 more
TL;DR: In this paper, the Fourier transforms of free induction decays are used for image reconstruction, and software methods for making automatic correction of these errors are proposed, and simple procedures for performing such corrections are described and illustrated.