Lee et al (12) reported a PET reporter gene detection of approximately 1.0 108 cells but did not perform a quantitative study. were performed after intravenous injection of the radiotracer fluorine 18Cradiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine (18F-FHBG). Linear (Glp1)-Apelin-13 regression analysis of both MR imaging and PET data and nonlinear regression analysis of PET data were performed, accounting for multiple injections per animal. Results MR imaging showed a positive correlation between MSC-TF-NP cell number and dephasing (dark) transmission (= .0001) and a lower detection limit of at least approximately 1.5 107 cells. PET reporter gene imaging shown a significant positive correlation between MSC-TF and target-to-background percentage with the linear model (= .0001, root mean square (Glp1)-Apelin-13 error = 0.523) and the nonlinear model (= .0001, root mean square error = 0.273) and a lower detection limit of 2.5 108 cells. Summary The authors quantitatively identified the limit of detection of MSC after CCT in swine by using clinical PET reporter gene imaging and medical MR imaging with cell prelabeling. ? RSNA, 2016 = 8) were performed with MSC marrow stromal cells without TF triple fusion (= 4) and with Matrigel (mock injection) (= 4). Seven swine were injected with 23 intracardiac cell injections consisting of eight control cell injections and 15 mixtures of MSC marrow stromal cells-TF triple fusion-NP nanoparticles and MSC marrow stromal cells-TF triple fusion; almost all animals in the beginning underwent MR imaging. Two swine were used to adjust prelabeling, workflow, and MR imaging (Glp1)-Apelin-13 sequences; therefore, five swine with 13 cell injections and nine NP nanoparticles intracardiac injections were analyzed after medical MR imaging. One of the seven swine died after MR imaging but before PET. Clinical MR imaging was followed by 18F-FHBG fluorine 18Cradiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine injection and PET/CT imaging for approximately 5 hours, cells harvesting, and ex lover vivo MR imaging (Fig 1b). Therefore, six swine with 13 cell injections and eight control injections underwent PET/CT. Details of injections and analysis are demonstrated in Number 1, and details of each injection in each animal, together with imaging modality used, are detailed in Table E1 (on-line). Open in a separate window Number 1a: General study design and workflow. Schematics for (a) preparation of intracardiac swine injection and (b) study design. MSC marrow stromal cells expressing TF triple fusion reporter gene (MSC marrow stromal cells-TF triple fusion) were expanded for approximately 2C3 weeks before swine study. MSC marrow stromal cells combination comprising MSC marrow stromal cells-TF triple fusion (Glp1)-Apelin-13 and MSC marrow stromal cells-TF triple fusion bearing SPIO superparamagnetic iron oxide NP nanoparticles was harvested and counted during a 2C4-hour period, and preinjection cell combination containing approximately 80% MSC marrow stromal cells-TF triple fusion, approximately 20% MSC marrow stromal cells-TF triple fusion NP nanoparticles, was prepared. MSC marrow stromal cells cell combination was loaded into 5-mL syringes with 50% Matrigel, at 200 106 cells/mL, and stored on snow. Next, cells were injected intramyocardially, 1 hour after thoracotomy, in the beating swine heart. Clinical MR imaging was performed in five swine. Next, the animal was transferred to clinical PET/CT scanner and injected with 18F-FHBG fluorine 18Cradiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine. Four hours later on, a series of four 15-minute static PET scans was acquired in six swine. Finally, the heart was harvested after scanning, Rabbit Polyclonal to DP-1 and ex lover vivo MR imaging was performed at the end of the study, 2 hours after harvest of heart. Open in a separate window Number 1b: General study design and workflow. Schematics.