Dr. Bogdanov discussed how multimodality registration of optical and magnetic resonance imaging (MRI) in the same voxels of live tissue could be aided by paramagnetic contrast agents that provide optical clearing (OC) effect.
His lab investigated the effects of gadobutrol (GB) and its combination with DMSO/water as potential OC agent for imaging subcutaneous red fluorescence; to use MRI as a tool for imaging of GB distribution in tissues. The OC effects after local application were investigated in vivo by segmentation of tumor fluorescence intensity (FI) images of TagRFP red fluorescent protein expression in a photon-counting setup. 3D GRE T1-weighted MRI pulse sequences at 1T (M3, Aspect Imaging) were used to image GB in vivo distribution.
The application of GB-containing OC mixtures showed a strong and statistically significant increase in tumor FI. The use of 3D T1w-GRE MRI pulse sequences applied in the same groups of animals showed that 1.0 M GB resulted in MR signal loss of the skin that coincided with OC (according to FI measurements). 0.7 M GB-containing OC compositions showed a delayed.