ABSTRACT
While the discovery of x-ray is commonly considered as a pivotal event, ushering in modern medical imaging, there have been various optical-based in vitro and in vivo modalities routinely used for centuries. Owing to the exponential technological innovations of the late nineteenth and twentieth centuries, imaging had an explosive growth, primarily in the emergence of new modalities and associated tools. During this period, a number of emerging technologies played key roles in advances in biomedical engineering and clinical practice. e contribution of these technologies can be summarized into (1) enabling objective and quantitative measurement of in vivo phenomena, (2) enhancing our understanding of disease process and interaction with therapeutic agents, and (3) new discoveries in the pathophysiology of disease and new diagnosis. Medical imaging is among the technologies that have strongly inuenced all these three aspects and beyond. e discovery of x-ray, as a landmark event, enabled us to see the “invisible,” opening a new era in medical diagnostics. More important, it opened up the thinking around the interaction of electromagnetic signal with human tissue and the utility of its selective absorption, scattering, diusion, and reection as a tool for understanding the physiology, evolution of disease, and therapy.
