Design of field-cycled magnetic resonance systems for small animal imaging

Phys Med Biol. 2006 Jun 7;51(11):2825-41. doi: 10.1088/0031-9155/51/11/010. Epub 2006 May 17.

Abstract

This paper presents a design study for a field-cycled magnetic resonance imaging (MRI) system directed at small animal imaging applications. A field-cycled MRI system is different from a conventional MRI system in that it uses two separate and dynamically controllable magnetic fields. A strong magnetic field is used to polarize the object, and a relatively weak magnetic field is used during signal acquisition. The potential benefits of field-cycled MRI are described. The theoretical dependences of field-cycled MRI performance on system design are introduced and investigated. Electromagnetic, mechanical and thermal performances of the system were considered in this design study. A system design for imaging 10 cm diameter objects is presented as an example, capable of producing high-duty-cycle polarizing magnetic fields of 0.5 T and readout magnetic fields corresponding to a proton Larmor frequency of 5 MHz. The specifications of the final design are presented along with its expected electromagnetic and thermal performance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Animals
  • Electromagnetic Fields*
  • Equipment Design
  • Image Enhancement*
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging*
  • Models, Animal
  • Phantoms, Imaging*
  • Sensitivity and Specificity
  • Stress, Mechanical
  • Temperature
  • Time Factors