The hystersalpingogram is usually carried out by a radiologist or an infertility specialist in a radiology suite under image intensification fluoroscopy (to minimize radiation exposure).  It should be performed after vaginal bleeding has ceased and prior to ovulation (to avoid flushing a fertilized egg back into the tube).  If the woman is allergic to iodine containing dye she should be pretreated with steroids.  Gentile administration of water soluble dye allows one to see the uterine cavity, and the Fallopian tubes.  Functional tubes are confirmed by the presence of dye spilling for the ends of the tubes.