Innovative CT fistulography method for chronic osteomyelitis: identifying fistulous passages and sequestration

Background Computed tomography with fistulography (CTF) using contrast material (CM) injected into a fistula is commonly used to visualize fistulous tracts (FT) in chronic osteomyelitis or chronic wounds. Typically, a CT scan is done twice: first without CM to identify sequestrum, followed by using CM to visualize the FT. Purpose To develop a streamlined and effective CTF method that reduces patient radiation exposure and lowers examination costs. Material and Methods The method employs hydrogen peroxide (H 2 O 2 ) as a contrast agent. When H 2 O 2 enters the FT, it breaks down into water and oxygen, spreading under low pressure. Since gas has a significantly lower radiopacity than iodinated contrast agents, gas-filled fistulas appear black on the CT monitor, while CM, foreign bodies, and bones appear white. This technique has been used in over 200 patients for the lower and uppser extremities, pelvis, spine, and chest. Results The images enabled a simultaneous investigation of the spatial relationship between the FT and sequestrum, irrespective of the body segment examined. Only a single scan was necessary. No complications or discomfort were reported by the patients. Conclusion This method enhanced the topographic diagnosis of FT and the spatial positioning of sequestrum or foreign bodies, halving patient radiation exposure. It eliminates the need for expensive iodinated contrast agents and their associated complications, significantly reducing examination costs and time.