Fluorescence Spectroscopy of Turbid Media

Abstract

The diagnosis of disease is becoming more and more a technologic task. The clinician’s goal is to assess the structural and functional changes in diseased tissue, infer the identity and stage of the disease, and predict the ultimate consequences to the organism as a whole, intervening with the proper treatment whenever possible.¹ The diagnostic ordnance varies, both for the suspected disease and with the specialty of the clinician. Radiologists, for example, assess gross structural abnormalities utilizing variations in tissue or contrast agent absorption of X-rays. This structural information, although useful diagnostically, provides limited insight into the molecular etiology and pathogenesis of the disease, factors now appreciated to be important prognostically and in selecting appropriate therapy.¹ Pathology provides the most widely used clinical method of elucidating chemical information from diseased tissues.^1.2 Traditional techniques of histology probe the microscopic structural alterations of diseased tissue. Using histochemical stains, many of the corresponding chemical alterations can be mapped out on a microscopic scale. The chief disadvantage of histologic techniques is that they can only be applied in vitro, necessitating the removal of tissue.² The requirement of biopsy limits the utility of this approach; it implies that only small areas of tissue, accessible to either biopsy forceps or needles, can be sampled.