A fistulagram uses a form of real-time x-ray called fluoroscopy and a barium-based contrast material to produce images of an abnormal passage within the body called a fistula. A sinogram is a similar procedure done to assess a sinus, an abnormal passage or cavity that originates or ends in one opening, often on the skin. Contrast material is used to help identify the start of the fistula/sinus, its pathway and what organs are involved. The Cephus Catheter creates a seal at the opening of the fistula, which allow contrast material to be injected under pressure to identify the entire tract.