The main purpose of this study was to explore the potential of optical active molecules as biomolecular photonic contrast agents in increasing the image contrast of biological structures in conjunction with optical polarimetric techniques using a preclinical phantom. The outcome of this study may contribute to enhanced detection of early diseases and pathologies in tissue.
In this study, a preclinical phantom was designed and experiments were performed using a backscattered polarimetric imaging system. By using the principles of a rotating retarder polarimeter and data reduction algorithm based on polarimetric measurement matrix, Stokes parameters were calculated and finally the Degree of Linear Polarization (DOLP) images were calculated. The obtained S0 and DOLP images were fused to obtain an enhanced image which offers a high contrast resolution. This step was repeated for each concentration of optically active molecular contrast agents added to the preclinical phantom. The signal-to-noise ratio (SNR), signal-to-background ratio (SBR) and the number of pixels detected as edges were calculated to determine the image quality.
The outcome of this study indicates clearly an increase in image quality parameters with increase in concentration of contrast agents like isopropyl alcohol, sugar solution and salt solution, to the preclinical phantom. It also indicates the DOLP and fused images provide unsurpassable image quality with respect to S0 images highlighting the fact that the polarized light measurements yield a better output than the total intensity measurements. Overall, this optical polarimetric system in conjunction with the contrast agents can contribute to an effective imaging system for enhanced imaging characteristics and early tumor or tissue pathologies detection.