PT - JOURNAL ARTICLE AU - Henrik Gutte AU - Adam E. Hansen AU - Majbrit M.E. Larsen AU - Sofie Rahbek AU - Sarah T. Henriksen AU - Helle H. Johannesen AU - Jan Ardenkjaer-Larsen AU - Annemarie T. Kristensen AU - Liselotte Højgaard AU - Andreas Kjær TI - Simultaneous Hyperpolarized <sup>13</sup>C-Pyruvate MRI and <sup>18</sup>F-FDG PET (HyperPET) in 10 Dogs with Cancer AID - 10.2967/jnumed.115.156364 DP - 2015 Nov 01 TA - Journal of Nuclear Medicine PG - 1786--1792 VI - 56 IP - 11 4099 - http://jnm.snmjournals.org/content/56/11/1786.short 4100 - http://jnm.snmjournals.org/content/56/11/1786.full SO - J Nucl Med2015 Nov 01; 56 AB - With the introduction of combined PET/MR spectroscopic (MRS) imaging, it is now possible to directly and indirectly image the Warburg effect with hyperpolarized 13C-pyruvate and 18F-FDG PET imaging, respectively, via a technique we have named hyperPET. The main purpose of this present study was to establish a practical workflow for performing 18F-FDG PET and hyperpolarized 13C-pyruvate MRS imaging simultaneously for tumor tissue characterization and on a larger scale test its feasibility. In addition, we evaluated the correlation between 18F-FDG uptake and 13C-lactate production. Methods: Ten dogs with biopsy-verified spontaneous malignant tumors were included for imaging. All dogs underwent a protocol of simultaneous 18F-FDG PET, anatomic MR, and hyperpolarized dynamic nuclear polarization with 13C-pyruvate imaging. The data were acquired using a combined clinical PET/MR imaging scanner. Results: We found that combined 18F-FDG PET and 13C-pyruvate MRS imaging was possible in a single session of approximately 2 h. A continuous workflow was obtained with the injection of 18F-FDG when the dogs was placed in the PET/MR scanner. 13C-MRS dynamic acquisition demonstrated in an axial slab increased 13C-lactate production in 9 of 10 dogs. For the 9 dogs, the 13C-lactate was detected after a mean of 25 s (range, 17–33 s), with a mean to peak of 13C-lactate at 49 s (range, 40–62 s). 13C-pyruvate could be detected on average after 13 s (range, 5–26 s) and peaked on average after 25 s (range, 13–42 s). We noticed concordance of 18F-FDG uptake and production of 13C-lactate in most, but not all, axial slices. Conclusion: In this study, we have shown in a series of dogs with cancer that hyperPET can easily be performed within 2 h. We showed mostly correspondence between 13C-lactate production and 18F-FDG uptake and expect the combined modalities to reveal additional metabolic information to improve prognostic value and improve response monitoring.