title: T1ρ relaxation time in brain regions increases with ageing: an experimental MRI observation in rats.
abstract: OBJECTIVE
  T1ρ variation is associated with neurodegenerative diseases. This study aims to observe T1ρ relaxation time changes in rat brains associated with normal ageing in Sprague-Dawley (SD) rats, Wistar Kyoto (WKY) rats and spontaneously hypertension rats (SHRs).
  
  
  METHODS
  18 male SD rats, 11 male WKY rats and 11 male SHRs were used. T1ρ measurement was performed at 3-T MR with a spin-lock frequency of 500 Hz. SD rats were scanned at the ages of 5, 8, 10 and 15 months. SHRs and WKY rats were scanned at the ages of 6, 9 and 12 months.
  
  
  RESULTS
  For SD rats, T1ρ at the thalamus, hippocampus and frontal cortices increased significantly from 5 to 15 months (p < 0.05). For the WKY rats and SHRs, the T1ρ values in the thalamus, hippocampus and frontal cortices also increased significantly from 6 to 12 months (p < 0.05). Furthermore, T1ρ in the thalamus, hippocampus and frontal cortices of SHRs were consistently higher than those of WKY rats at the ages of 6, 9 and 12 months (p < 0.05). The percentage regional T1ρ differences between WKY rats and SHRs did not change during ageing.
  
  
  CONCLUSIONS
  An increase in T1ρ was associated with age-related changes of the rat brain.
  
  
  CONCLUSIONS
  An age-related and hypertension-related T1ρ increase in rat brain regions was observed in the thalamus, hippocampus and frontal cortical regions of the rat brain.
authors.affiliation: 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.affiliation: 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.|2 Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.affiliation: 3 Division of Neurosurgery, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: Gang
authors.initials: G
authors.lastname: Lu
authors.affiliation: 4 School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Li H
authors.initials: LH
authors.lastname: Zhang
authors.affiliation: 5 Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Zhi Y
authors.initials: ZY
authors.lastname: Chen
authors.affiliation: 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: Yì-Xiáng J
authors.initials: YX
authors.lastname: Wáng
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley