TY - JOUR
T1 - T1 estimation for aqueous iron oxide nanoparticle suspensions using a variable flip angle SWIFT sequence
AU - Wang, Luning
AU - Corum, Curtis A.
AU - Idiyatullin, Djaudat
AU - Garwood, Michael
AU - Zhao, Qun
PY - 2013/8
Y1 - 2013/8
N2 - Purpose 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. Methods 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. Results 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. Conclusion VFA-SWIFT is able to achieve accurate T1 quantification of aqueous super-paramagnetic iron oxide nanoparticle suspensions up to 7 mM.
AB - Purpose 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. Methods 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. Results 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. Conclusion VFA-SWIFT is able to achieve accurate T1 quantification of aqueous super-paramagnetic iron oxide nanoparticle suspensions up to 7 mM.
KW - positive contrast
KW - super-paramagnetic iron oxide nanoparticles
KW - sweep imaging with Fourier transformation
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U2 - 10.1002/mrm.24831
DO - 10.1002/mrm.24831
M3 - Article
C2 - 23813886
AN - SCOPUS:84881180990
SN - 0740-3194
VL - 70
SP - 341
EP - 347
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
IS - 2
ER -