title: Imaging and quantification of iron-oxide nanoparticles (IONP) using MP-RAGE and UTE based sequences.
abstract: 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).
  
  
  
  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.
  
  
  
  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 R1and IONP concentration up to ∼30 mM.
  
  
  
  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.
authors: Department of Radiology, University of California, San Diego, California, USA.|Department of Radiology, China-Japan Friendship Hospital, Beijing, China.
authors: Wen
authors: W
authors: Hong
authors: Department of Radiology, University of California, San Diego, California, USA.|Ningbo Jansen NMR Technology Co., Ltd, Cixi, Zhejiang Province, China.
authors: Qun
authors: Q
authors: He
authors: Department of Radiology, University of California, San Diego, California, USA.
authors: Shujuan
authors: S
authors: Fan
authors: Applied Science Lab, GE Healthcare, San Diego, California, USA.
authors: Michael
authors: M
authors: Carl
authors: Department of Radiology, University of California, San Diego, California, USA.
authors: Hongda
authors: H
authors: Shao
authors: Department of Radiology, University of California, San Diego, California, USA.
authors: Jun
authors: J
authors: Chen
authors: Department of Radiology, University of California, San Diego, California, USA.|Radiology Service, VA San Diego Healthcare System, San Diego, California, USA.
authors: Eric Y
authors: EY
authors: Chang
authors: Department of Radiology, University of California, San Diego, California, USA.
authors: Jiang
authors: J
authors: Du
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003911:Dextrans / Q000493:pharmacokinetics*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D058185:Magnetite Nanoparticles; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10
keywords: Cones; IONP; MP-RAGE; MRI; UTE; iron oxide nanoparticles