In ovo imaging using ostrich eggs – physiological embryonal development on serial CT scans

Ziel/Aim In-ovo imaging using ostrich eggs has been described as a potential alternative to common animal testing using rats or mice. The main advantage of this approach is its independence from small animal imaging devices as ostrich eggs provide good image quality on regular CT, MRI or PET used in clinical routine in examinations of humans. However, many questions regarding physiological development and systematic evaluation of image quality using ostrich eggs are open. This study aims at describing physiological development of ostrich embyros on serial CT scans.

Methodik/Methods 100 eggs were included in this study, comprising 63 fertilized and 37 non-fertilized eggs. Artificial incubation was performed for 37 days. On developmental days (DD) 0, 10, 19, 22, 25, 28, 31, 34 and 37 CT scans were performed using a standard Siemens Biograph mCT40. Full-dose scan parameters were kept constant. Density of yolk, albumen and shell as well as volumes of air cell, embryo, yolk and egg shell were determined. In fertilized eggs, the size of different osseous structures was investigated.

Ergebnisse/Results Detection of embryonal development was technically successful and feasible in 100%. Reliable distinguishment of fertilized and non-fertilized eggs is achieved as early as DD 22. After that, continuous embryonal development is depicted on CT scans and osseous structures become visible on DD 25, starting with femur bones. Volume changes of egg compartments were found to be similar as compared to data from derived from embryonal sections.

Schlussfolgerungen/Conclusions During artificial incubation of ostrich eggs, embryonal development can reliably be depicted using standard CT scans used in clinical routine for humans. In research facilities without access to small animal imaging devices, ostrich eggs might open the door for preclinical imaging studies (e.g. development of new radiotracers in nuclear medicine). This study contributes to the implementation of ostrich eggs as an alternative to common animal testing.

Publication History

Article published online:
08 April 2021