Digital autoradiography imaging using direct irradiation of a CCD between 278-309 K

Using direct irradiation of a CCD for beta autoradiography is principally limited by variations in cumulative pixel dark current across the device modulated by small changes in temperature. We have used a modified fixed pattern noise correction method to address this problem at room temperature, and tested the method using ¹⁴C microscales and labeled mouse tissue samples. An evaluation is included of the minimum activity levels which can be detected between 278-309 K, determining the quantitative and qualitative imaging capabilities and improvements of such an approach for imaging distributed sources (such as the microscales) at various levels of activity. Further investigation is presented of the effects of large temperature changes between acquisition of real data and blank frames used for image correction. Empirical formulas describing the relative dark current thermal behavior have been developed and applied to low activity, distributed sources such as ¹⁴C microscales and thin tissue mouse brain sections labeled with ³⁵S. The corrected images obtained by the CCD-based imaging system were compared with digitized film images of the same samples. It was found that the proposed approach can successfully detect weak distributions from radiolabeled tissue at room temperature.