FIGURE 6.7 Comparisons highlighting different fluorescent biomarkers. (a) White light reflectance only used in (a-c); (b) Cy5 fluorescence (pseudocolored cyan, overlaid on reflectance) image highlighting deeply buried nerve (long-stemmed arrow); (c) yellow fluorescent compound (YFP) fluorescence (pseudocolored yellow, overlaid on reflectance) image highlights additional branches (large arrowhead); (d) white light reflectance only used in (d-f); (e) FAM fluorescence (pseudocolored cyan, overlaid on reflectance) image highlighting a stained buried nerve branch (large arrowhead); (f) Cy5 fluorescence (pseudocolored green, overlaid on reflectance) image highlighting a tumor (small arrowheads). SOURCE: Reprinted with permission from Whitney, M.A., J.L. Crisp, L.T. Nguyen, B. Friedman, L.A. Gross, P. Steinbach, R.Y. Tsien, and Q.T. Nguyen. 2011. Fluorescent peptides highlight peripheral nerves during surgery in mice. Nature Biotechnology 29:352-356.
and lymph nodes that may need to be carefully avoided or excised as part of the operational procedure.25
The primary causes of death in the United States today are heart disease, cancer, and pulmonary disease, such as emphysema.26 In all of these modern ailments, early detection is the key to effective intervention. Since, in their early stages, these diseases often develop with minor or no symptoms, appropriate routine screening of at-risk populations must be implemented to detect disease in apparently healthy individuals. These screens must be low-cost, minimally invasive, and have low false-positive results in order to prevent unnecessary follow-on procedures. Imaging methods can provide a very effective approach to meeting these criteria.
Recent large-scale clinical trials have demonstrated the ability of low-dose x ray CT scanning as a very effective method to screen for lung cancer tumors,