This tutorial will cover the basic technical background in the field of image guided procedures and computer aided surgery. The tutorial will begin with an overview of the clinical issues with a focus on minimally invasive techniques in interventional radiology. The basic technology components such as image acquisition devices, localizers, registration techniques, and display methods will be discussed. A historical overview including some of the early work in the field will be presented. Case studies will also be discussed with a focus on the use of electromagnetic tracking for image-guided abdominal interventions. A summary of research issues and directions for future research will also be given.