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Proceedings Paper

Motion Artifact In 2DFT MR Imaging
Author(s): A. D. Nelson; R. J. Alfidi; A. Lent; M. Clampitt; M. Kritzer; F. Miraldi; C. Schultz; S. Kopiwoda
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Paper Abstract

Respiratory motion has been observed to produce artifacts in MR images of the abdomen and thorax. In order to experimentally characterize this artifact, a phantom was moved cyclically in the imaging field in order to investigate the effects of 1. amplitude of motion, 2. speed of motion, and 3. direction of motion. All images were obtained with a 0.30 Tesla magnet using a spin-echo sequence and two-dimensional Fourier transform, 2DFT, reconstruction. In 2DFT imaging a steady frequency encoding gradient is applied during MR signal acquisition which is preceded by a sequence of varying phase encoding gradients which are perpendicular to the frequency encoding direction. The artifact due to periodic motion consists of repeated copies of the edge of the object which are displaced from the original object in the phase-encoded direction. The distance between the actual object and the first echo is inversely proportional to the number of MR signal acquisitions per motion cycle. The clarity of both the artifact and the object is reduced as the amplitude of motion is increased. Simulations of motion patterns confirm experimental results. Respiratory gating has been applied in both abdominal and cardiac studies. These studies resulted in improved image clarity and elimination of repeated copies of organ edges in the reconstructed image.

Paper Details

Date Published: 28 August 1984
PDF: 7 pages
Proc. SPIE 0486, Medical Imaging and Instrumentation '84, (28 August 1984); doi: 10.1117/12.943218
Show Author Affiliations
A. D. Nelson, University Hospitals (United States)
R. J. Alfidi, University Hospitals (United States)
A. Lent, Technicare Corporation (United States)
M. Clampitt, University Hospitals (United States)
M. Kritzer, Technicare Corporation (United States)
F. Miraldi, University Hospitals (United States)
C. Schultz, University Hospitals (United States)
S. Kopiwoda, University Hospitals (United States)


Published in SPIE Proceedings Vol. 0486:
Medical Imaging and Instrumentation '84
James A. Mulvaney, Editor(s)

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