Document Detail


Single-sided mobile NMR apparatus using the transverse flux of a single permanent magnet.
MedLine Citation:
PMID:  19577401     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study presents a simple design for a mobile, single-sided nuclear magnetic resonance (NMR) apparatus which uses the magnetic flux parallel to the magnetization direction of a single, disc-shaped permanent magnet polarized in radial direction. The stray magnetic field above the magnet is approximately parallel to the magnetization direction of the magnet and is utilized as the B(0) magnetic field of the apparatus. The apparatus weighs 1.8 kg, has a compact structure and can be held in one's palm. The apparatus generates a B(0) field strength of about 0.279 T at the center of apparatus surface and can acquire a clear Hahn echo signal of a pencil eraser block lying on the RF coil in one shot. Moreover, a strong static magnetic field gradient exists in the direction perpendicular to the apparatus surface. The strength of the static magnetic field gradient near the center of the apparatus surface is about 10.2 T/m; one-dimensional imaging of thin objects and liquid self-diffusion coefficient measurements can be performed therein. The available spatial resolution of the one-dimensional imaging experiments using a 5 x 5 mm horizontal sample area is about 200 mum. Several nondestructive inspection applications of the apparatus, including distinguishing between polyethylene grains of different densities, characterizing epoxy putties of distinct set times and evaluating the fat content percentages of milk powders, are also demonstrated. Compared with many previously published designs, the proposed design bears a simple structure and generates a B(0) magnetic field parallel to the apparatus surface, simplifying apparatus construction and simultaneously rendering the selection of the radiofrequency coil relatively flexible.
Authors:
Wei-Hao Chang; Jyh-Horng Chen; Lian-Pin Hwang
Publication Detail:
Type:  Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-07-03
Journal Detail:
Title:  Magnetic resonance imaging     Volume:  28     ISSN:  1873-5894     ISO Abbreviation:  Magn Reson Imaging     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2009-12-07     Completed Date:  2010-02-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8214883     Medline TA:  Magn Reson Imaging     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  129-38     Citation Subset:  IM    
Affiliation:
Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Equipment Design
Equipment Failure Analysis
Magnetic Resonance Spectroscopy / instrumentation*
Magnetics / instrumentation*
Miniaturization
Transducers*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Evaluation of intracranial stenoses and aneurysms with accelerated 4D flow.
Next Document:  Blood oxygen level-dependent and perfusion magnetic resonance imaging: detecting differences in oxyg...