Quantitation of tumor foci in an experimental murine tumor model using computer-assisted video imaging

A method is described in which both number and diameter of lung tumor foci obtained from an experimental murine tumor model of pulmonary metastasis are quantified using a digital imaging device. Lungs obtained from mice previously inoculated with tumorigenic cells are stained with India ink and Fekete's solution. Using appropriate exposure settings and top-lighting, a charged-coupled device digital camera is used to obtain the image of the organ. The image is then analyzed by the associated video imaging analysis software. Diameter of tumor foci on the image is expressed in image pixels and foci are quantitated. Density and size threshold parameters are set, thereby eliminating the variability resulting from the subjective nature of manual enumeration of tumor foci. The method is objective and reproducible and should be useful for studies where quantifying tumor foci diameter and number directly from the organ is required.