White matter shifts in MRI

Rehabilitating the Lorentz sphere in magnetic resonance

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

A thorough exposition and analysis of the role of the Lorentz sphere in magnetic resonance is presented from the fundamental standpoint of macroscopic magnetostatics. The analysis will be useful to those interested in understanding susceptibility and chemical shift contributions to frequency shifts in magnetic resonance. Though the topic is mature, recent research on white matter shifts in the brain promotes the notion of replacing the Lorentz sphere with a generalized Lorentzian cylinder, and has put into question the long standing spherical approach when elongated structures are present. The cavity shape issue can be resolved by applying Helmholtz's theorem, which can be expressed in a differential and an integral formulation. The general validity of the Lorentz sphere for any situation is confirmed. Furthermore, a clear exposition of the “generalized approach” is offered, using the language of Lorentz's theory. With the rehabilitation of the Lorentz sphere settled, one must consider alternative contributions to white matter shifts and a likely candidate is the effect of molecular environment on chemical shifts.

Original languageEnglish (US)
Pages (from-to)40-46
Number of pages7
JournalJournal of Magnetic Resonance
Volume270
DOIs
StatePublished - Sep 1 2016

Fingerprint

Magnetic resonance
Magnetic resonance imaging
magnetic resonance
Magnetic Resonance Spectroscopy
shift
Chemical shift
chemical equilibrium
Language
Rehabilitation
Magnetostatics
Brain
magnetostatics
Research
Patient rehabilitation
frequency shift
brain
theorems
magnetic permeability
formulations
cavities

Keywords

  • Chemical shift
  • Lorentz sphere
  • Magnetic susceptibility
  • White matter shifts

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Biochemistry
  • Biophysics
  • Condensed Matter Physics

Cite this

White matter shifts in MRI : Rehabilitating the Lorentz sphere in magnetic resonance. / Barbara, Thomas.

In: Journal of Magnetic Resonance, Vol. 270, 01.09.2016, p. 40-46.

Research output: Contribution to journalArticle

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