What is the difference between tubal water and salpingography?

Fallopian tube water is the doctor in the use of saline and gentamicin and other drugs injected into the fallopian tube, feel the injection process has no resistance and other circumstances to judge, easy to appear false positive. Salpingography is to inject iodophor into the fallopian tube, and then after a period of time to take X-ray film, to judge the fallopian tube situation.