Short Review: Pathology of the image big data era using electron microscopy

The human body is mysterious, consisting of innumerable fine and complex structures and a vast amount of information. The field of modern pathology has been systematized around the findings and observations obtained from light microscopy. However, such observations in the visible light range are limited to those at the cellular level; thus, observations of cellular ultrastructures are difficult. Therefore, only vague information can be collected. Various imaging methodologies and tissue staining techniques have been created to further understand the complexity of biological tissues. Using such approaches, it has been realized that cellular morphology data that comprehensively acquire biological tissue information can be treated as new omics information, termed the 'Totalities of body tissue morphology (morphome)'. In addition, it is also possible to revisit vague morphological information quantitatively and objectively using knowledge relating to the latest scientific information. Currently, new technologies are allowing additional frontiers to be opened. Indeed, I believe that a new revolution is about to take place regarding the 'viewing' of tissues by innovative imaging technologies such as 'wide-area electron microscopy (EM)', which can observe a wide area of several millimeters or more with nano-level resolution. Moreover, with the advent of cutting-edge information technology, I expect big data processing to be more innovative. Through the incorporation of these new methodologies, the field of pathology is expected to deepen through the identification of previously unknown structures, the quantification of infrequent rare events, the new reclassification of diseases, and the automatic diagnosis of diseases. In this review, I introduce the innovation of the EM imaging and discuss the field of pathology with regard to the big data era.