Ovarian cancer is a prototypic disease for this type of clinical imaging system called intra-operative imaging. Except in Stage IV, the tumors are confined to the pelvis or abdomen and typically involve extensions or implants onto pelvic or abdominal organs or membranes. Tumor debulking surgery is common early in the disease process as many of the tumors can be identified by appearance or feel in the skilled surgeon's hands. The major problems are that tumors can be diffuse and numerous, of various sizes, and often not readily visible in the surgical field.