The fallopian tubes cannot be seen under negative ultrasound, but it can be seen that the fallopian tubes are diseased, such as fluid in the fallopian tubes and pus in the fallopian tubes, because the fallopian tubes are filled with fluid, either water or pus, which can lead to tubular or even salami-like echogenicity, some of which are echogenic, some of which are cloudy echogenicity, etc. In this way, the fallopian tubes can be seen. The normal fallopian tubes without fluid and tumors are invisible and indistinguishable under the negative ultrasound, but the uterus and ovaries can be clearly seen under the negative ultrasound, such as the endometrial echogenicity, the more subtle structural changes of the endometrium, as well as endometrial polyps and submucosal fibroids, which can be seen very clearly.