Magnetic Resonance Imaging for the Determination of Magnetic Susceptibility of Materials

✍ Scribed by O. Beuf; A. Briguet; M. Lissac; R. Davis

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 319 KB
• Volume: 112
• Category: Article
• ISSN: 1064-1866
• DOI: 10.1006/jmrb.1996.0120

✦ Synopsis

A magnetic resonance imaging method for volume magnetic known susceptibility, one may describe easily the shape dissusceptibility estimate of materials immersed in a liquid containing tortions and the intensity aberrations that occur in the surresonant nuclei is proposed. The method uses either the standard rounding liquid (4, 5) if this liquid contains resonant nuclei. spin-echo Fourier imaging technique or the projection-reconstruc-The aim of the present study is to correlate the size of the tion technique. Image distortions of cylindrical macroscopic sustypical distortion caused by a cylinder with the value of the ceptibility inhomomogeneities are analyzed and a correlation is magnetic susceptibility of the cylinder material using spinestablished between the susceptibility value and the size of image echo imaging based on Fourier reconstruction and projecdeformation along the read gradient. For measurements, the sustion-reconstruction techniques.

ceptibility of the liquid surrounding the sample (here deionized

We begin by recalling the first susceptibility measurewater) serves as a reference, and characteristic distances between ments based on NMR spectroscopic techniques and perparticular points, usually highlights in the distorted image, are related to the susceptibility difference between the two media. formed on liquids (6). The approach works also for powder Different samples, mainly prosthetic materials with a large suscepcharacterization (7). In the liquid state, the greatest care tibility range from 5 to 200 ppm in absolute value, have been must be taken in the interpretation of susceptibility effects investigated, and the accuracy of susceptibility determination is on chemical shifts. In addition, the selective observation of discussed.