title: Compromised perfusion in femoral head in normal rats: distinctive perfusion MRI evidence of contrast washout delay.
abstract: OBJECTIVE
  The femoral head is prone to osteonecrosis. This study investigated dynamic contrast-enhanced (DCE) MRI contrast washout features of the femoral head and compared the data with data from other bony compartments in normal rats.
  
  
  METHODS
  7-month-old Wistar rats were used. DCE MRI of the right hip (n=18), right knee (n=12) and lumbar spine (n=10) was performed after an intravenous bolus injection of Gd-DOTA (0.3 mmol kg(-1)). Temporal resolution was 0.6 s for hip and spine, and 0.3 s for knee. The total scan duration was 8 min for hip and spine, and 4.5 min for knee. The regions of interest for enhancement measurement included femoral head, proximal femoral diaphysis, distal femoral diaphysis and epiphysis, proximal tibial epiphysis and diaphysis, and lumbar vertebrae L1-5.
  
  
  RESULTS
  Femoral head showed no enhancement signal decay during the DCE MRI period, while all other bony compartments showed a contrast washin phase followed by a contrast washout phase. In the knee joint, the contrast washout of the proximal tibia diaphysis was slower that of other bony compartments of the knee.
  
  
  CONCLUSIONS
  Based on the evidence of delayed contrast washout, this study showed that blood perfusion in the femoral head could be compromised in normal rats.
authors.affiliation: Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China.
authors.forename: Y-X J
authors.initials: YX
authors.lastname: Wang
authors.forename: J F
authors.initials: JF
authors.lastname: Griffith
authors.forename: M
authors.initials: M
authors.lastname: Deng
authors.forename: H
authors.initials: H
authors.lastname: T Ma
authors.forename: Y-F
authors.initials: YF
authors.lastname: Zhang
authors.forename: S-X
authors.initials: SX
authors.lastname: Yan
authors.forename: A T
authors.initials: AT
authors.lastname: Ahuja
mesh_terms: D000818:Animals; D003287:Contrast Media; D005270:Femur Head / Q000098:blood supply*; D005271:Femur Head Necrosis / Q000503:physiopathology; D006571:Heterocyclic Compounds; D018810:Magnetic Resonance Angiography / Q000379:methods; D009942:Organometallic Compounds; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate