[2-phase contrast for the CT imaging of fistulae]

To improve the diagnosis of fistulas in CT by using a new method. 68 CT examination of fistulas from 1990 to 1995 were evaluated retrospectively. The examinations were performed in two phases: The regions of interest were scanned as usual, in the case of abdominal fistulas after filling the bowels with contrast medium. In the second phase, the fistulas were filled with highly concentrated contrast medium and re-examined. The presentation of this examination was carried out in a wide window and a high centre. In 59 of the 68 cases the fistula and a communication with an organ or an abscess was found, in 9 cases only the fistulous tract. The fistula and its surrounding structures can be well defined each with a different and individual density. By means of the chosen method the different density readings are visualised. Therefore, the 2-phase contrast method can improve fistula diagnosis by using CT.