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Proceedings Paper

Statistical properties of spin noise in MRI
Author(s): Tianhu Lei; Hee Kwon Song; Felix W. Wehrli; Timothy P. L. Roberts
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Paper Abstract

Spin noise is inherent in magnetic resonance. It is caused by incomplete cancellation of spin moments when the external static magnetic field is absent or by their small but finite fluctuations when the magnetic field is applied. Spin noise is viewed as the variation of thermal equilibrium macroscopic magnetization (TEMM), and can be described statistically. For MRI, TEMM is shown to be characterized by a Binomial distribution and is well approximated by a Gaussian. Parameters of this Gaussian distribution are determined by the spin density and the ratio of population difference over the total population of spins in a unit volume of the sample. Statistics of spin noise not only confirm Bloch's prediction of spin noise in the absence of the external magnetic field, but also give a more accurate account of its behavior under various conditions. These statistics also provide a new insight into the limits of spatial resolution in magnetic resonance microscopy (MRM) and are consistent with Glover and Mansfield' corresponding conclusions based on their experiments.

Paper Details

Date Published: 18 March 2008
PDF: 9 pages
Proc. SPIE 6913, Medical Imaging 2008: Physics of Medical Imaging, 69130H (18 March 2008); doi: 10.1117/12.772145
Show Author Affiliations
Tianhu Lei, Univ. of Pennsylvania (United States)
Children's Hospital of Philadelphia (United States)
Hee Kwon Song, Univ. of Pennsylvania (United States)
Children's Hospital of Philadelphia (United States)
Felix W. Wehrli, Univ. of Pennsylvania (United States)
Children's Hospital of Philadelphia (United States)
Timothy P. L. Roberts, Univ. of Pennsylvania (United States)
Children's Hospital of Philadelphia (United States)


Published in SPIE Proceedings Vol. 6913:
Medical Imaging 2008: Physics of Medical Imaging
Jiang Hsieh; Ehsan Samei, Editor(s)

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