Virtual Biopsy [Point of View]

Biopsy is a medical procedure involving the surgical removal of tissue for close examination. As a rule, a biopsy is performed on suspected cancerous tissue in order to determine the appearance of cancer cells and the cancer stage. Obtaining accurate evaluation of the suspected tissue requires high-resolution optical imaging that allows a clear view of the cell structure. This requires chemical treatment in some cases, freezing, dying, thinly slicing, and examining the tissue under a high-magnification microscope. The downside of the biopsy is that it is an invasive surgical procedure, there could be serious surgical complications such as bleeding and/or infection, and it can take several days to weeks before the final pathological report is ready to be presented to the patient. These limitations have motivated researchers to develop ways to achieve a high-resolution internal cellular imaging of the cancerous tissue noninvasively and in real time. From the advent of noninvasive three-dimensional (3D) imaging techniques such as ultrasound and magnetic resonance imaging (MRI) for more than 50 and 30 years, respectively, there have been extensive efforts by many researchers to attain "virtual biopsy." Some techniques have been shown and proven to be highly effective diagnostic tools for different cancer types. However, none is being effectively developed as a screening tool that can replace traditional biopsy. Consequently, many people in the field are asking and wondering if virtual biopsy is a realistic screening tool for the future. A proper screening of the cancerous tissue requires highly magnified images of an internal cellular structure. In order to perform subsurface imaging, 3D imaging modalities such as computed tomography (CT) scan, MRI, ultrasound, optical coherence tomography (OCT), and confocal microscope could be used and could be candidates for "virtual biopsy." This paper will discuss some of the proposed techniques for virtual biopsy.