title: Evaluation of the Genisys4, a bench-top preclinical PET scanner.
abstract: The Genisys4 is a small bench-top preclinical PET scanner designed to enable imaging in biology, biochemistry, and pharmacology laboratories and imaging centers. Here, we compare its performance with that of a well-established preclinical PET scanner.
  
  
  METHODS
  Subcutaneous and lung tumor xenografts were used to compare lesion detectability and treatment responses to chemotherapy (gemcitabine) using (18)F-FDG PET. The size of subcutaneous xenografts (L1210 and L1210-10K leukemia cells) and lung metastases (B-16 melanoma cells) was measured on small-animal CT images. Tumor (18)F-FDG uptake was expressed as percentage injected dose per gram. Using list-mode data, serial images of the left ventricular blood pool were used to generate time-activity curves.
  
  
  RESULTS
  Subcutaneous xenografts (range, 4-12 mm; mean ± SD, 6.1 ± 1.7 mm) and lung metastases (range, 1-5 mm; mean, 2.1 ± 1.2 mm) were detected equally well with both scanners. Tumor (18)F-FDG uptake measured with both scanners was highly correlated for subcutaneous xenografts (r(2) = 0.93) and lung metastases (r(2) = 0.83). The new Genisys4 scanner and the established scanner provided comparable treatment response information (r(2) = 0.93). Dynamic imaging sequences permitted the generation of left ventricular blood-pool time-activity curves with both scanners.
  
  
  CONCLUSIONS
  Using subcutaneous and lung xenografts, a novel and an established preclinical PET scanner provided equivalent information with regard to lesion detection, tumor (18)F-FDG uptake, tumor response to treatment, and generation of time-activity curves. Thus, the Genisys4 provides a small, efficient bench-top preclinical PET alternative for quantitatively studying murine tumor models in biology, biochemistry, and pharmacology laboratories and preclinical imaging centers.
authors.affiliation: Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California 90095-1782, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Herrmann
authors.forename: Magnus
authors.initials: M
authors.lastname: Dahlbom
authors.forename: David
authors.initials: D
authors.lastname: Nathanson
authors.forename: Liu
authors.initials: L
authors.lastname: Wei
authors.forename: Caius
authors.initials: C
authors.lastname: Radu
authors.forename: Arion
authors.initials: A
authors.lastname: Chatziioannou
authors.forename: Johannes
authors.initials: J
authors.lastname: Czernin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D016513:Mice, SCID; D008904:Miniaturization; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000295:instrumentation* / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: 18F-FDG; preclinical PET; scanner performance; tumor models