title: Insights into bone metabolism of avian embryos in ovo via 3D and 4D 18F-fluoride positron emission tomography.
abstract: OBJECTIVE
  The chick embryo is a well-known economical in vivo model system and is widely applied in preclinical research, e.g., bone development studies. It is therefore surprising that no studies concerning the application of (18)F-fluoride microPET to bone metabolism have been reported so far. This may be due to motion artifacts or the lack of convenient tracer injection sites.
  
  
  METHODS
  We resolved the above problems using a combination of sample preparation, anesthesia, microPET imaging, and computational processing, and describe a convenient way of visualizing three- and four- dimensional features of bone metabolism in living chick embryos.
  
  
  RESULTS
  The application of (18)F-fluoride microPET facilitates repeat measurements, highly reproducible and motion-artifact-free skeletal imaging, and provides quantitative measurements of in ovo metabolic activities in the bones of developing chick. During microPET measurement, radio tracer was injected intravascularly using a custom-made catheter system, allowing us to additionally investigate early time points in tracer kinetics and uptake.
  
  
  CONCLUSIONS
  Our results show that bone metabolism in living chick embryos can be reproducibly studied and quantified in ovo, even for multiple tracer injections over a longer time period. The use of dynamic (18)F-fluoride microPET imaging made it possible to visualize and analyze even small bone structures with excellent quality. Moreover, as our data are comparable to data from corresponding rodent experiments, the use of embryonated chicken eggs is a convenient and economical alternative to other animal models.
authors.affiliation: Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Beutenbergstr. 11a, 07745 Jena, Germany.
authors.forename: Lydia
authors.initials: L
authors.lastname: Würbach
authors.forename: Alexander
authors.initials: A
authors.lastname: Heidrich
authors.forename: Thomas
authors.initials: T
authors.lastname: Opfermann
authors.forename: Peter
authors.initials: P
authors.lastname: Gebhardt
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Saluz
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002642:Chick Embryo; D047108:Embryonic Development; D005462:Fluorine Radioisotopes; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007267:Injections; D010063:Ovum / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D011849:Radioactive Tracers; D011875:Radionuclide Angiography; D015203:Reproducibility of Results; D013997:Time Factors; D062666:Vascular Access Devices
chemical_list: D005462:Fluorine Radioisotopes; D011849:Radioactive Tracers