Purpose: We have developed a method of quantitation for correcting tissue absorption in in vivo bioluminescence imaging (BLI).
Procedures: Variations of luciferin emission spectrum were determined and were related to photon absorption to determine a correction curve. This was validated by combining BLI with tomoscintigraphy and tomodensitometry, which were applied to a lymphoma model.
Results: Tissue absorption affects luciferin emission spectrum, mainly for wavelengths less than 620 nm. So, we have selected two filters bordering 620 nm to quantify spectral modifications. A significant correlation was obtained between the spectral analysis and the percentage of transmitted light through tissues (R(2) = 0.97). On a disseminated tumour model, we have shown that such a methodology is of great interest to compare bioluminescent signals and to get more accurate quantitative data about tumour proliferation.
Conclusions: Spectral analysis allows improved quantitation of BLI and could be of value to perform pharmacological studies and to follow tumour progression in models with tumours evolving in different locations.