To provide the early disease diagnosis, medicals need a high-resolution adaptive optical imaging technology, which will be able to capture individual biological tissue. Nevertheless, light scattering and deformed images make some limitations such as a risk of abruptly lowering resolution of targeting cells, which are deep inside. Consequently, current techniques allow medicals to observe and research cells, which are only on the tissue surface. Therefore, scientists from Korea managed to develop the high-resolution adaptive optical image that has the ability to depose biological tissue-induced image deformation.

The development was made by the scientific group, led by Professor Wonshik Choi, from the Korea University in collaboration with the Asan Medical Center, the Pohang University of Science and Technology and the Institute for Basic Science.

During the observation of the early stages of the disease, the sub-micron-scale biological reactions, which are happening inside living tissues, have been optically unapproachable, limiting the effectiveness of optical microscopy. The thick biological tissue causes not only the light scattering but the deviation of remaining signal waves. Therefore, scientists created the innovative technology that can correct light scattering and identify aberrations of waves, which are reflected from the samples separately, and eliminate them. The method that is used by the group is termed the collective accumulation of single scattering (CASS) microscopy. It can identify the aberrations of single scattering, causing the twice higher resolution compared to current CASS microscopes.

This technology records the time-gated complex-field maps of backscattered waves over various illumination channels and performs a closed-loop optimization of signal waves for both forward and phase-conjugation processes. Scientists have managed to achieve the spatial resolution of the image up to 600 nm analyzing of a 700 μm-thick tissue layer. Using the closed-loop operations, they can independently identify the aberrations for the illumination and reflection paths without the need for a guide star. This novel development providing the capability to perform ultra-high spatial resolution imaging deep within scattering media will open new opportunities for studying important biological reactions in detail and significantly improve early disease diagnosis.