Performing longitudinal measurements in rodents using small animal PET imaging

Although tremendous effort and finances were spent in developing small animal PET scanners, this technology remains under utilized as a research tool to study disease states. To advance this goal, we previously developed a microfluidic blood sampling device to overcome the problem of blood sampling and fluid volume loss when performing quantitative PET studies. The device was previously shown to be reliable for deriving input function without changing the physiological stability of a mouse. In this study, we improved methodologies and optimized the animal surgical preparation necessary for prolonging the patency of chronic indwelling catheters. We have also added several features to improve functionality and ease of use for a new prototype of a microfluidic blood sampler and tested this device for accuracy in determining FDG blood curves in rats with a chronic indwelling catheter. We modified the hardware and software of the previous blood sampling device to reduce the cost and provide a more user-friendly interface. We successfully prepared the animal for deriving input functions for multiple microPET studies. Our results suggest that longitudinal microPET imaging in the same animal is possible. These new developments should increase the use of PET imaging in drug development and translational research using small animals.