Historically, the role of visual media in diagnostic narratives seems clear and unambiguous. In the age of image-guided therapy, visual control over the human body has attained a completely new level, significantly shaping scientific and public debates on illness, imaging, and medical procedures. Practical functions of medical imaging continue to expand, restrained only by the pace of technological progress. This adds another link in the narrative chain of a patient's medical course, as technology itself enters the picture, underscoring the self-evident narrative closure of medical diagnosis. Despite the educational use of public, visual narratives such as TV shows, autobiographic stories, movies, and novels, in medical schools to guide future doctors' expectations of clinical practice, their influence on patient behavior and communication has not received much attention. By drawing on examples from social and popular media, the paper argues that visual medical insights contribute to the analytical dimension of popular visual narratives. Yet, there seems to be no comprehensive, theoretical approach within the field of visual narratology that takes into account the constitutive, if not indispensable, presence of image material for an unfolding medico-scientific and/or medical lay discourse. The paper discusses narrative strategies of medical diagnosis together with corresponding theoretical approaches, concluding with an analysis of the potential applicability of sociologist Karin Knorr Cetina's concept of "viscourse" to medical diagnostic reasoning and popular visual narratives.