title: Evaluation of magnetic nanoparticle samples made from biocompatible ferucarbotran by time-correlation magnetic particle imaging reconstruction method.
abstract: BACKGROUND
  Molecular imaging using magnetic nanoparticles (MNPs)-magnetic particle imaging (MPI)-has attracted interest for the early diagnosis of cancer and cardiovascular disease. However, because a steep local magnetic field distribution is required to obtain a defined image, sophisticated hardware is required. Therefore, it is desirable to realize excellent image quality even with low-performance hardware. In this study, the spatial resolution of MPI was evaluated using an image reconstruction method based on the correlation information of the magnetization signal in a time domain and by applying MNP samples made from biocompatible ferucarbotran that have adjusted particle diameters.
  
  
  METHODS
  The magnetization characteristics and particle diameters of four types of MNP samples made from ferucarbotran were evaluated. A numerical analysis based on our proposed method that calculates the image intensity from correlation information between the magnetization signal generated from MNPs and the system function was attempted, and the obtained image quality was compared with that using the prototype in terms of image resolution and image artifacts.
  
  
  RESULTS
  MNP samples obtained by adjusting ferucarbotran showed superior properties to conventional ferucarbotran samples, and numerical analysis showed that the same image quality could be obtained using a gradient magnetic field generator with 0.6 times the performance. However, because image blurring was included theoretically by the proposed method, an algorithm will be required to improve performance.
  
  
  CONCLUSIONS
  MNP samples obtained by adjusting ferucarbotran showed magnetizing properties superior to conventional ferucarbotran samples, and by using such samples, comparable image quality (spatial resolution) could be obtained with a lower gradient magnetic field intensity.
authors.affiliation: School of Science and Technology, Meiji University, Higashimita Tama, Kawasaki, Kanagawa, Japan. y_ishr@meiji.ac.jp
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Ishihara
authors.forename: Takumi
authors.initials: T
authors.lastname: Honma
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nohara
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000465:Algorithms; D001672:Biocompatible Materials / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D003911:Dextrans / Q000737:chemistry*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides