Fluorescence and ultrasound imaging of orthotopic pancreatic tumor implants and measurement of tumor size. A-H. This mouse was imaged two weeks after orthotopic injection of a human pancreatic cell line (XPA-1) stably expressing red fluorescent protein (RFP). A-C. Evaluation of tumor size by whole body imaging of an anesthetized mouse. A. Bright field and color fluorescence images were overlaid to show the coronal image of the fluorescent tumor. B. Enlarged whole body fluorescence image of tumor. This image was obtained using a color (non-quantitative) fluorescence imaging camera. C. Monochrome (quantitative) fluorescence image of the tumor shown in panels A and B. This coronal image was analyzed using ImageJ software to determine the cross-sectional size of the tumor in millimeters squared (mm2). D-F. Evaluation of tumor size at necropsy. D. Overlay of bright field and color fluorescence images showing the fluorescent tumor implant at necropsy. E. Enlarged color fluorescence-only image of the tumor as shown in D. F. As for panel C above, the cross-sectional size of the tumor shown in panels D and E was determined using ImageJ software. G. This ultrasound image of the pancreatic tumor mass was obtained using a Visual Sonics Vevo 770 small animal ultrasound imaging system. With the anesthetized mouse in a lateral position, the 40 MHz ultrasound transducer was oriented to obtain coronal image slices of the tumor. H. Image showing the tumor at its maximum cross sectional size in the coronal plane. Vevo 770 imaging software was used to determine the cross sectional size (in mm2) of the tumor.