Noninvasive molecular imaging is increasingly being used in animal models of human disease for diagnostic and therapeutic strategies.The quantified results of molecular imaging can effectively provide real time biological process information in biomedical research and translational study.On the basis of currently reporter gene imaging systems are seldom in characterizing the relationships between tumor growth, reporter gene activity, glucose metabolism and morphological change, the goal of this study was to investigate the correlation among various modalities in offering tumor volume information, growth characteristics and reporter gone activity in progressive tumors.Methods: Dual-reporter genes expressing of murine colorectal adenocarcinoma (CT-26/tk-luc)-bearing BALB/c mice were used as subjects.Imaging modalities including bioluminescence imaging (BLI), 18F-FEAU and 18F-FDG microPET were applied to characterize the behaviors and metabolism of tumors.Micro-ultrasound (microUS) and histopathology were carried out to validate the anatomical change in tumor progression.Results: The in vitro and in vivo doubling time of tumor growth were lsimilar between genes transduced and parental cells.The quantified results of BLI and lgF-FEAU microPET showed the similar trend in an increasing pattern of tumor growth kinetic when size up to about 1000 mm3, then gradually decline afterward since over this region.The similar results of increasing patterns were demonstrated by 18F-FDG metabolic imaging (SUV 0.42±0.04 to 1.62±0.07), caliper measurement (103.2±6.8 to 2311.5±103.1 mm3) and microUS (112.8±18.7 to 2773.8±147.5 mm3).The increase of metabolic activity, tumor volume, anatomical change and tumor necroses were characterized by these three modalities with histopathology in decreasing patterns of the photon signals from the optical and nuclear reporter imaging studies.Conclusion: The concurrent optical and nuclear reporter imaging systems associated with microUS and tumor pathology have shown a closely descriptions in tumor representation, characterization and quantification in CT-26/tk-luc tumor-bearing mice.Although the reporter gene imaging is appropriate for accurately monitoring the tumor biophysics in living subjects, but is also limited in characteristics and categories of the tumor.The results suggest that the application of reporter gene imaging should be considered in the large or highly necrotic tumors in preclinical studies.