The sonographic assessment includes a transabdominal and an endovaginal exam or endorectal in virginal patients. The endocavitary probe allows identification of tender organs and can assess the fallopian tubes, ovaries and sigmoid colon. Simple cysts are the most common ovarian masses. It is anechoic, smoothly marginated, unilocular with posterior enhancement. Usually functional and disappear within two cycles. If it does not resolve after three cycles, it is not functional. Theca lutein cysts are small, bilateral cysts associated with PCOD, mole or ovarian stimulation and resolve after treatment. Para-ovarian and para-tubal cysts are remnants of the Wolffian duct. They are mistaken for ovarian cysts. They are small, thin walled, nontender, unchanging in size and separate from the ovary. Complex ovarian masses can be benign or malignant. The primary criteria for a malignant ovarian mass usually are a diameter >4 cm, thick wall or septum >3 mm, large solid or mostly solid mass or nodularity. Ascites, large nodes or a mass fixed or nonmovable on EV exam, are signs of extension locally from the primary mass. A serous cystadenoma or cystadenocarcinoma is the most common ovarian neoplasm. Masses are thin walled, unilocular and may have thin septa or papilla. The malignant ones are thick walled, multilocular with multiple papilla and ascites. Mucinous cystadenoma or carcinoma comprises 20% of all benign and 10% of malignant ovarian masses. They are usually very large, often exceeding 15 cm. They have multiple septa with low-level internal echoes due to the mucin. Hemorrhagic cyst is echogenic and as clot forms, fibrin bands appear as fine septations giving a fishnet appearance. Retracting clot is triangular. An endometrioma may have a varied appearance on US often with a ground glass appearance and low level echoes. There may be layering of echogenic material and the mass may look solid or cystic. The mass is usually tender to palpation with the EV probe. Ectopic pregnancy may have a wide variety of presentations. Echogenic free fluid does not always mean a ruptured ectopic. Dermoid cyst is the most common germ cell tumor. About 30% are malignant if present is a preadolescent. There may be fat-fluid levels, calcification, and an echogenic mass with shadowing and/or bright linear bands that may represent hair. Abscess. There is usually fever and increased white count with a multilocular mass with thick walls that is tender to the touch. The mass is nonmobile. Treatment is antibiotics and/or drainage. Hematosalpinx and hydrosalpinx may be called a septated ovarian cyst but in the correct scan plane the tubular nature of the mass is evident. It is separate from, but adjacent to the ovary with layering of echogenic debris, pus or blood. May be previous PID or tubal ligation. Ovarian torsion. The ovary is enlarged with small peripheral cysts. A larger cyst may also be present. No vascularity seen. If a small amount of flow is present then the ovary can be salvaged if it is untwisted. There may be increased flow if there has been inflammation or it has de-torted.