Menu

Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Quantitative diffusion coefficient maps using fast spin-echo MRI

Author:
  • Sara Brockstedt
  • C Thomsen
  • Ronnie Wirestam
  • Stig Holtås
  • Freddy Ståhlberg
Publishing year: 1998
Language: English
Pages: 877-886
Publication/Series: Magnetic Resonance Imaging
Volume: 16
Issue: 8
Document type: Journal article
Publisher: Elsevier

Abstract english

In this work, we have evaluated the performance of a diffusion-sensitive fast spin-echo (FSE) pulse sequence. The proposed pulse sequence utilises velocity-compensating diffusion-encoding gradients and includes the collection of navigator echoes. Spoiler gradients were inserted in the slice-selecting direction to minimise effects from stimulated echoes. Calculations of the b values showed that cross-terms between imaging gradients and diffusion gradients only led to a marginal increase of b values. Pixel-wise calculation of apparent diffusion coefficient (ADC) maps was performed numerically, considering cross-terms between diffusion-encoding and imaging gradients. The sequences investigated used echo train lengths of 16, 8 and 4 echoes and were encoded in either the slice-, frequency- or phase-encoding direction. In order to allow for higher b values a pulse-sequence version using non-motion compensating diffusion-encoding gradients was written. Phantom measurements were performed and the diffusion coefficients of water and acetone were reasonable. Seven healthy volunteers (age 28-50 years) were examined and apparent diffusion coefficient values agreed well with expected values. Diffusion-weighted images, apparent diffusion coefficient maps and images corresponding to the trace of the diffusion tensor of good quality were retrieved in vivo.

Keywords

  • Radiology, Nuclear Medicine and Medical Imaging
  • Navigator echoes Article Outline
  • Phase correction
  • Motion-compensating gradients
  • Diffusion
  • Fast spin-echo

Other

Published
  • ISSN: 1873-5894
Freddy Ståhlberg
E-mail: freddy [dot] stahlberg [at] med [dot] lu [dot] se

Professor

Medical Radiation Physics, Lund

+46 46 17 31 19

+46 70 688 31 19

32

Professor

Diagnostic Radiology, (Lund)

+46 46 17 70 30

32

Project manager

MR Physics

32