When the Small Animal Imaging Program (SAIP) opened at the NCI-Frederick campus in October 2006, "it was a huge thing for Frederick researchers," says Dr. Peter Choyke of the Center for Cancer Research (CCR) and NCI project officer overseeing the facility. Now the most comprehensive animal-imaging program at NCI, the SAIP offers state-of-the-art facilities including CT, ultrasound, fluorescence optical imaging, PET-SPECT CT, and a human 3 Tesla MRI machine specially configured to scan up to 6 mice at once, allowing high-throughput analysis for large experiments.
Unusual among small-animal imaging facilities, animals entering the SAIP from the main animal holding facility at Frederick can be returned afterwards for further study or follow-up. Most animal imaging facilities, which scan animals brought in from outside laboratories, harbor pathogens that could present a risk if introduced back into the laboratory environment; therefore, the animals must be euthanized after the imaging procedures. However, the SAIP maintains the same pathogen-free environment as the adjacent animal facilities.
"An animal in an adjacent facility could come through our pass-through door and be in the same environment that they would have been in their own holding area. So this allows us to do repeated scans on that animal," says Dr. Choyke. This is especially important for studies monitoring the spontaneous development of cancer in transgenic animal models, he explains. "Much like [carcinogenesis] in humans, we don't know when a tumor is going to occur or where it's going to occur, so we need to take serial images."
Many NCI researchers based in Bethesda also make use of the SAIP though collaborative relationships with scientists at NCI-Frederick, or by establishing their own animal colonies at the main animal facility in Frederick, which is part of the Laboratory Animal Sciences Program.
Although extramural investigators do not have direct access to the SAIP, the laboratory provides inclusive educational opportunities including training programs, visiting fellowships, workshops, and shared imaging protocols. Members of the SAIP are also working with small-animal imaging facilities across the country to develop a common informatics system to store and access imaging data.