RT Journal Article SR Electronic T1 Small-Animal PET Imaging of Isolated Perfused Rat Heart JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 495 OP 499 DO 10.2967/jnumed.113.129429 VO 55 IS 3 A1 Tomohiko Yamane A1 Min-Jae Park A1 Dominik Richter A1 Stephan G. Nekolla A1 Mehrbod S. Javadi A1 Constantin Lapa A1 Samuel Samnick A1 Andreas K. Buck A1 Ken Herrmann A1 Takahiro Higuchi YR 2014 UL http://jnm.snmjournals.org/content/55/3/495.abstract AB The assessment of myocardial radiotracer kinetics, including cardiac extraction fraction and washout, requires the study of isolated perfused hearts to avoid analytic error due to tracer recirculation and systemic metabolites. Analysis of the isolated perfused rat heart by a high-resolution small-animal PET system may offer both reliable evaluation of cardiac tracer kinetics and tomographic images. Methods: An isolated perfused heart system was modified to accommodate the small PET gantry bore size. Isolated rat hearts were perfused via the Langendorff method under a constant flow of Krebs-Henseleit buffer containing 18F-FDG with a rate of 5 mL/min and placed in the field of view of the commercially available small-animal PET system. Dynamic PET imaging was then performed, with 18F-FDG uptake in the isolated perfused heart verified by γ counter measurements. Additionally, a rat heart of myocardial infarction was also studied in this system with static PET imaging. Results: Dynamic PET acquisition of the isolated heart under constant 18F-FDG infusion demonstrated continuous increase of activity in the heart. Correlation between cardiac activity (MBq) measured with the PET system and measurements made with the γ counter were excellent (R2 = 0.98, P < 0.001, n = 10). Tracer input rate (MBq/min) was also well correlated with cardiac tracer uptake rate (MBq/min) (R2 = 0.87, P < 0.001, n = 12). PET imaging of the heart with myocardial infarction showed a clear tracer uptake defect corresponding to the location of scar tissue identified by autoradiography and histology. Conclusion: Combining the Langendorff method of isolated rat heart perfusion with high-resolution small-animal PET allows for the reliable quantification of myocardial tracer kinetics. This novel assay is readily adapted to available small-animal PET systems and may be useful for understanding myocardial PET tracer kinetics.