In vivo uptake and localization of ^99mTc-pertechnetate in pigs using single-photon emission computed tomography

Radionuclide scintigraphy in animals provides valuable information about pathologic and physiologic processes. Technetium-99m (^99mTc) has played an important role in diagnostic imaging over the last several decades. It can be used in the form of either ^99mTc-pertechnetate or ^99mTc-labeled radiopharmaceuticals. The in vivo uptake and localization of ^99mTc-pertechnetate in pigs were studied using single-photon emission computed tomography (SPECT). The ^99mTc-pertechnetate was administered to pigs by intravenous and intragastric injections to compare their uptake and localization. The effect of anesthesia in pigs on ^99mTc biodistribution was observed through imaging. The results showed that unconsciousness in the pig induced by isoflurane resulted in the irregular uptake of ^99mTc-pertechnetate when it was directly administered intragastrically. This behavior might have been due to isoflurane reducing the pig's gastrointestinal motility. Data on the nuclear medicine tomographic imaging technique using gamma rays in live animals are limited. Therefore, this observation provided useful information for basic biological research on animal models using SPECT. It is also benefit to the development of new ^99mTc-labeled radiopharmaceuticals in diagnostic nuclear medicine.