a

b

Tubal occlusion. (a) Spot radiograph demonstrates abrupt cutoff of the left fallopian tube. (b) Spot radiograph demonstrates cutoff of contrast material in the isthmic portions of both fallopian tubes, with bulbous dilatation of the distal aspects of the opacified portions. These findings can be seen with postsurgical occlusion (eg, following tubal ligation).

http://radiographics.rsna.org/content/26/2/419.figures-only