Multiscale three-dimensional imaging of the placenta

Placental function involves multiple different processes which operate at different scales from centimetres to nanometres. Everything that the placenta does from mediating blood flow to gene expression, occurs within a three-dimensional anatomical framework. This review outlines how multiscale three-dimensional imaging approaches can provide insight into placental structure and function. Three-dimensional imaging approaches include microCT, confocal, super resolution, light-sheet, and serial block-face scanning electron microscopy. Used together, these approaches allow three-dimensional imaging of the placenta across the scales at which different processes occur. Three-dimensional imaging illustrates the spatial relationships between structures and visualises structures that are not clearly apparent in two-dimensions. Understanding the three-dimensional structure of the placenta enables exploration of the relationship between structure and function, including through the development of computational models based on realistic geometries. Three-dimensional imaging approaches will enhance our understanding of placental function in health and disease.