Hello, this is Dr. Herisa answering your question. I read very carefully your problem. As far as you may know the HSG or hysterosalpingogram is the kind of examination used in cases when Tubal Factor Infertility(any anatomic abnormality that prevents the sperm and egg from uniting) is to be detected, which means if the cause of a possible infertility is any of the fallopian tube or both of them. The fact that the fallopian tube,the left one is patent means that it is not blocked, so it is opened and no obstructions are visualized. The right side has a cornual blockage which means that the tubes are blocked at the end near the uterus. This can occur because of infection, endometriosis, dried secretions in the tube, mucus in the tube or scar. Also what I would suggest is that your sister should consult an OBGYN doctor, because there are many clinical management protocols about this problem and this specialized doctor could provide her with a useful solution especially if she wants to get pregnant. Good luck and hopefully my answer would help