Imaging and quantification of iron‐oxide nanoparticles (IONP) using MP‐RAGE and UTE based sequences

• Published in: Magnetic resonance in medicine Vol. 78; no. 1; pp. 226 - 232
• Main Authors: Hong, Wen, He, Qun, Fan, Shujuan, Carl, Michael, Shao, Hongda, Chen, Jun, Chang, Eric Y, Du, Jiang
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.07.2017
• Subjects: Adiabatic; Adiabatic flow; Brain - diagnostic imaging; Brain - metabolism; Cones; Dextrans - pharmacokinetics; Humans; Image contrast; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Imaging; Imaging, Three-Dimensional - methods; IONP; Iron; iron oxide nanoparticles; Magnetic resonance; Magnetic Resonance Imaging - instrumentation; Magnetic Resonance Imaging - methods; Magnetite Nanoparticles; Molecular Imaging - instrumentation; Molecular Imaging - methods; MP‐RAGE; MRI; Nanoparticles; Phantoms, Imaging; Reproducibility of Results; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Trajectory analysis; Tubes; UTE; IONP; Cones; MP-RAGE; MRI; iron oxide nanoparticles; UTE
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.26371

Purpose To investigate two‐dimensional (2D) and three‐dimensional (3D) ultrashort echo time (UTE) and 3D magnetization‐prepared rapid gradient‐echo (MP‐RAGE) sequences for the imaging of iron‐oxide nanoparticles (IONP). Methods The phantoms were composed of tubes filled with different IONP concentrations ranging from 2 to 45 mM. The tubes were fixed in an agarose gel phantom (0.9% by weight). Morphological imaging was performed with 3D MP‐RAGE, 2D UTE, 2D adiabatic inversion recovery–prepared UTE (2D IR‐UTE), 3D UTE with Cones trajectory (3D Cones), and 3D IR‐Cones sequences. Quantitative assessment of IONP concentration was performed using R2*(1/T2*) and R1 (1/T1) measurements using a 3 Tesla (T) scanner. Results The 3D MP‐RAGE sequence provides high‐contrast images of IONP with concentration up to 7.5 mM. Higher IONP concentration up to 37.5 mM can be detected with the UTE sequences, with the highest IONP contrast provided by the 3D IR‐Cones sequence. A linear relationship was observed between R2* and IONP concentration up to ∼45 mM, and between R1 and IONP concentration up to ∼30 mM. Conclusion The clinical 3D MP‐RAGE sequence can be used to assess lower IONP concentration up to 7.5 mM. The UTE sequences can be used to assess higher IONP concentration up to 45 mM. Magn Reson Med 78:226–232, 2017. © 2016 International Society for Magnetic Resonance in Medicine