title: In ovo serial skeletal muscle diffusion tractography of the developing chick embryo using DTI: feasibility and correlation with histology.
abstract: BACKGROUND
  Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length.
  
  
  RESULTS
  From 84 normally developing chick embryos, 5 were randomly chosen each day from incubation days 5 to 18 and scanned using 3.0 Tesla magnetic resonance imaging. A dual-cooling technique is used before and during imaging. Eggs were cracked for making histological specimen after imaging. 3 eggs were serially imaged from days 5 to 18. We show that skeletal muscle fibers can be tracked in hind limb in DTI beginning with incubation day 8. Our data shows a good positive correlation between quantitative DTI and histologic parameters (FA vs FiberArea%: r= 0.943, p<0.0001; Fiber_length vs Limb_length: r=0.974, p<0.0001). The result of tracked fibers in DTI during incubation corresponds to the development of chick embryonic skeletal muscle as reported in the literature.
  
  
  CONCLUSIONS
  Diffusion tensor imaging can provide a noninvasive means of evaluating skeletal muscle development in ovo.
authors.affiliation: Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. xujianr@hotmail.com
authors.forename: Zien
authors.initials: Z
authors.lastname: Zhou
authors.forename: Zachary
authors.initials: Z
authors.lastname: Delproposto
authors.forename: Lianming
authors.initials: L
authors.lastname: Wu
authors.forename: Jianrong
authors.initials: J
authors.lastname: Xu
authors.forename: Jia
authors.initials: J
authors.lastname: Hua
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Ye
authors.forename: Zishu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jiani
authors.initials: J
authors.lastname: Hu
authors.forename: E Mark
authors.initials: EM
authors.lastname: Haacke
mesh_terms: D000818:Animals; D002642:Chick Embryo / Q000196:embryology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006614:Hindlimb / Q000196:embryology; D024510:Muscle Development; D018485:Muscle Fibers, Skeletal / Q000166:cytology; D018482:Muscle, Skeletal / Q000196:embryology*