How to distinguish between an ovarian and paraovarian cyst

(Panel A) Transabdominal image shows a normal right ovary (O) beneath the bladder (B) and to the side of the uterus (U). A 1.9 cm dominant follicle/cyst (C) is seen arising from the ovary as documented by the "claw sign" (arrowheads) of ovarian tissue extending around the periphery of the cyst covering about 50% of its diameter. The cyst is round and predominately anechoic.
(Panel B) In a different patient, a transabdominal split image shows the transverse and sagittal appearance of a 2.4 cm paraovarian cyst (calipers). It is behind the bladder (B) and clearly separate from the ovary (O). The cyst is thin walled and anechoic.