One of the biggest areas of scientific visualization (ViSC) application is Medicine: with the evolution of image acquisition techniques the capacity and fidelity of image diagnosis were extended. Due to the large number of medical exams that output images, several visualization systems have been developed dealing with specific problems in this area in the last few years. The growing of World Wide Web-based applications and the modern trend of cooperative work in scientific research gave rise to a new class of systems, the so-called collaborative visualization systems. This survey presents an overview of ViSC in Medicine emphasizing the different approaches for collaborative visualization, and discussing difficulties still found for its real utilization.