Biology

Clearing

Biomedical engineering

Materials science

Clearance

Computer security

Tissue engineering

Urology

Medical physics

Economics

Transparency (behavior)

Computer science

Computational biology

Business

Optical transparency

Physics

Nanotechnology

Optics

Biological tissue

Data science

Medicine

Finance

Optoelectronics

Native tissue

Optical imaging

Pathology

iScience

Three-dimensional (3D) optical imaging techniques can expand our knowledge about physiological and pathological processes that cannot be fully understood with 2D approaches. Standard diagnostic tests frequently are not sufficient to unequivocally determine the presence of a pathological condition. Whole-organ optical imaging requires tissue transparency, which can be achieved by using tissue clearing procedures enabling deeper image acquisition and therefore making possible the analysis of large-scale biological tissue samples. Here, we review currently available clearing agents, methods, and their application in imaging of physiological or pathological conditions in different animal and human organs. We also compare different optical tissue clearing methods discussing their advantages and disadvantages and review the use of different 3D imaging techniques for the visualization and image acquisition of cleared tissues. The use of optical tissue clearing resources for large-scale biological tissues 3D imaging paves the way for future applications in translational and clinical research.

Biomedical Applications of Tissue Clearing and Three-Dimensional Imaging in Health and Disease