T1 estimation for aqueous iron oxide nanoparticle suspensions using a variable flip angle SWIFT sequence
Version of Record online: 28 JUN 2013
© 2013 Wiley Periodicals, Inc.
Magnetic Resonance in Medicine
Volume 70, Issue 2, pages 341–347, August 2013
How to Cite
Wang, L., Corum, C. A., Idiyatullin, D., Garwood, M. and Zhao, Q. (2013), T1 estimation for aqueous iron oxide nanoparticle suspensions using a variable flip angle SWIFT sequence. Magn Reson Med, 70: 341–347. doi: 10.1002/mrm.24831
- Issue online: 23 JUL 2013
- Version of Record online: 28 JUN 2013
- Manuscript Accepted: 8 MAY 2013
- Manuscript Revised: 29 APR 2013
- Manuscript Received: 2 NOV 2012
- NIH. Grant Numbers: P41RR008079, P41EB015894, R21CA139688, KL2RR033182
- National Center for Research Resources. Grant Number: S10RR023706
- T1 mapping;
- super-paramagnetic iron oxide nanoparticles;
- sweep imaging with Fourier transformation;
- positive contrast
T1 quantification of contrast agents, such as super-paramagnetic iron oxide nanoparticles, is a challenging but important task inherent to many in vivo applications in magnetic resonance imaging. In this work, a sweep imaging with Fourier transformation using variable flip angles (VFAs-SWIFT) method was proposed to measure T1 of aqueous super-paramagnetic iron oxide nanoparticle suspensions.
T1 values of various iron concentrations (from 1 to 7 mM) were measured using VFA-SWIFT and three-dimensional spoiled gradient-recalled echo with VFAs (VFA-SPGR) sequences on a 7 T MR scanner. For validation, T1 values were also measured using a spectroscopic inversion-recovery sequence on a 7 T spectrometer.
VFA-SWIFT demonstrated its advantage for quantifying T1 of highly concentrated aqueous super-paramagnetic iron oxide nanoparticle suspensions, but VFA-SPGR failed at the higher end of iron concentrations. Both VFA-SWIFT and VFA-SPGR yielded linear relationships between the relaxation rate and iron concentrations, with relaxivities of 1.006 and 1.051 s−1 mM−1 at 7 T, respectively, in excellent agreement with the spectroscopic measurement of 1.019 s−1 mM−1.
VFA-SWIFT is able to achieve accurate T1 quantification of aqueous super-paramagnetic iron oxide nanoparticle suspensions up to 7 mM. Magn Reson Med 70:341–347, 2013. © 2013 Wiley Periodicals, Inc.