PT - JOURNAL ARTICLE AU - Hsiao Ming Wu AU - Chun-Hu Wu AU - Ya-Yao Huang AU - Miao-Ling Tsai AU - Szu-Fu Chen AU - Kai-Yuan Tzen TI - Performing longitudinal quantitative PET studies in rats is routinely feasible DP - 2016 May 01 TA - Journal of Nuclear Medicine PG - 1899--1899 VI - 57 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/57/supplement_2/1899.short 4100 - http://jnm.snmjournals.org/content/57/supplement_2/1899.full SO - J Nucl Med2016 May 01; 57 AB - 1899Objectives In the past, performing quantitative small animal PET study with arterial input function was technically challenging. Here, we report a procedure how we prepared a rat to ease radiotracer injections and performing blood sampling procedures. We performed 12 quantitative PET studies with 2 rats. Our experience showed that performing longitudinal, quantitative FDG PET studies with arterial input functions in rats is easy and routinely feasible.Methods Two rats underwent microsurgical procedures for repeated arterial blood sampling and bolus injections. The cannula were sealed with micro-ports with self-adhesive membranes; the catheter and injection ports were then placed subcutaneously. A week after surgery, each rat had two quantitative FDG PET studies performed on two consecutive days, one study with and another study without the influence of 2% isoflurane anesthesia. Each study had 15 serial blood samples taken from the arterial cannula followed by a 20 minutes dynamic brain PET scan. Blood samples were taken with an automated microfluidic device allowing take small samples (<1 µℓ for deriving input function or 50µℓ when plasma/whole blood FDG ratios were calculated). The same study protocol was repeated in the following two weeks. A total of 6 studies were performed on each rat. DATA ANALYSIS: Tissue FDG uptakes were sampled by drawing ROIs on the parietal lobes of brain PET images. Cerebral metabolic rates of glucose (CMRG; in unit of µmol/100min/g) were calculated using a modified version of Operational Equation, where a k4 microparameter was included to account for phosphatase activities and tissue heterogeneities (Yu et al., 2009).Results With 2 rats, we performed 12 PET studies (6 morning sessions; 2 studies per session) with arterial blood samples successfully. The rats remained in good health during and after PET studies (please see graph A of the figure). The CMRG obtained from the two rats with (i.e. unconscious state) or without anesthesia (i.e. awake state) were also shown in the figure, graphs B. The CMRG were suppressed more than 50% under the isoflurane anesthesia.Conclusions For the first time, CMRG of a rat were monitored under physiological conditions overtime using indwelling catheters and FDG PET imaging. We obtained comparable CMRG values as those obtained by the DG-autoradiographic methods. Our successful experience suggests that similar PET studies can be performed routinely using radiotracers where plasma separation and metabolites correction are also required for input function derivation. $$graphic_9B6284CD-7970-448C-B3A0-60138F0E5830$$