title: Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development.
abstract: OBJECTIVE
  To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla.
  
  
  METHODS
  Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis.
  
  
  RESULTS
  The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R(2) = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation.
  
  
  CONCLUSIONS
  Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population.
  
  
  CONCLUSIONS
  • APTW signals followed a decreasing exponential curve with age. • The most significant APTW changes appeared within the first year • At maturation, larger APTW decreases and lower APTW appeared in white matter • MTR signals followed an increasing exponential curve with age.
authors.affiliation: Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China.
authors.forename: Huiying
authors.initials: H
authors.lastname: Kang
authors.affiliation: Philips Healthcare, Beijing, China.
authors.forename: Xuna
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA. jzhou@mri.jhu.edu.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China. ppengyun@yahoo.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Peng
mesh_terms: D000577:Amides; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011522:Protons; D012016:Reference Values; D066127:White Matter / Q000000981:diagnostic imaging*
chemical_list: D000577:Amides; D011522:Protons
keywords: Amide proton transfer imaging; Biomarker; Brain maturation; MRI; Myelination