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Assessment of MRI contrast agent concentration by quantitative susceptibility mapping (QSM) : application to estimation of cerebral blood volume during steady state

Author:
  • Emelie Lind
  • Linda Knutsson
  • Robin Kämpe
  • Freddy Ståhlberg
  • Ronnie Wirestam
Publishing year: 2017-06-19
Language: English
Pages: 1-12
Publication/Series: Magnetic Resonance Materials in Physics, Biology, and Medicine
Document type: Journal article
Publisher: Springer

Abstract english

Objective: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. Materials and methods: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test–retest study. By selecting a CSF reference region of interest (ROI), the values of all QSM images were shifted to show no CA-induced change in CSF. CA concentration and cerebral blood volume (CBV) were estimated using shifted QSM data. CSF reference ROI optimization was evaluated by investigation of CBV repeatability. The CBV age dependence was analysed and tissue T2* relaxivity was estimated. Results: The best repeatability of CBV, using an optimal CSF reference ROI, showed test-versus-retest correlations of r = 0.81 and r = 0.91 for white and grey matter, respectively. A slight CBV decrease with age was observed, and the estimated in vivo T2* relaxivity was 85 mM−1s−1. Conclusion: Provided that a carefully selected CSF reference ROI is used to shift QSM image values, susceptibility information can be used to estimate concentration of contrast agent and to calculate CBV.

Keywords

  • Other Clinical Medicine
  • Cerebral blood volume
  • Cerebrovascular circulation
  • Contrast agents
  • Magnetic resonance imaging
  • Magnetometry
  • QSM

Other

Inpress
  • MR Physics
  • ISSN: 0968-5243
Freddy Ståhlberg
E-mail: freddy.stahlberg [at] med.lu.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