Repeated assessment of changes in testes size in canaries by X-ray computer tomography.

Numerous studies have evaluated changes in time of testicular development in birds by exploratory laparotomy or post-mortem autopsy. The invasive nature of these approaches has obviously limited the frequency at which these measures can be collected. We demonstrate here that accurate assessment of gonadal size can be reliably and repeatedly obtained by computer-assisted X-ray tomography (CT scans). This approach provides images of the testes in the three orthogonal planes that allow measuring either the largest diameter or even the volume of the testes, providing results that match those obtained by surgical approaches.