Fig. 3.

21-year-old male with perianal complex fistulas.

CT fistulography images clearly show complex perianal fistula tracts in subcutaneous shallow area, in rear of coccyx. Three anomalous fistula tracts with external opening were successfully identified. Extent of disease and complicated spatial information are better seen on volume rendering image. Minute fistula was not clearly seen (white dovetail arrow in D) on MR image. CT fistulography (A-C) and MRI (contrast-enhanced liver acquisition with volume acceleration [LAVA] in D, F; T2-weighted with fat suppression in E): thick fistula (white arrow), minute fistula (white dovetail arrow), and long fistula (black dovetail arrow) are identified.