Cerenkov luminescence imaging (CLI) is an emerging cost effective modality that uses conventional small animal
optical imaging systems and clinically available radionuclide probes for light emission. CLI has shown good correlation
with PET for organs of high uptake such as kidney, spleen, thymus and subcutaneous tumors in mouse models. However,
CLI has limitations for deep tissue quantitative imaging since the blue-weighted spectral characteristics of Cerenkov
radiation attenuates highly by mammalian tissue. Large organs such as the liver have also shown higher signal due to the
contribution of emission of light from a greater thickness of tissue. In this study, we developed a simple model that
estimates the effective tissue attenuation coefficient in order to correct the CLI signal intensity with a priori estimated
depth and thickness of specific organs. We used several thin slices of ham to build a phantom with realistic attenuation.
We placed radionuclide sources inside the phantom at different tissue depths and imaged it using an IVIS Spectrum
(Perkin-Elmer, Waltham, MA, USA) and Inveon microPET (Preclinical Solutions Siemens, Knoxville, TN). We also
performed CLI and PET of mouse models and applied the proposed attenuation model to correct CLI measurements.
Using calibration factors obtained from phantom study that converts the corrected CLI measurements to %ID/g, we
obtained an average difference of less that 10% for spleen and less than 35% for liver compared to conventional PET
measurements. Hence, the proposed model has a capability of correcting the CLI signal to provide comparable
measurements with PET data.