Which ultrasound appearance is characteristic of ovaries in a patient with PCOS?

The characteristic ultrasound appearance of ovaries in a patient with polycystic ovary syndrome (PCOS) is often described as a "string of pearls" or "oyster ovaries." This appearance is due to the presence of multiple small follicles around the periphery of the ovaries, which can give them a distinctive pattern reminiscent of a string of pearls. These follicles are typically less than 10 mm in size and can be seen on transvaginal ultrasound, contributing to the diagnosis of PCOS.

The string of pearls appearance signifies the presence of many small, immature follicles, which is one of the key features in the follicular dysfunction associated with PCOS. This characteristic can help differentiate PCOS from other ovarian conditions during imaging.

Other ultrasound findings may include enlarged and cystic ovaries or solid masses, but these findings are not definitive for PCOS. Normal appearing ovaries would not suggest the presence of the syndrome, as the hallmark of PCOS is the presence of the atypical follicular arrangement. Thus, the string of pearls or oyster ovary appearance is the most important and telltale sign on ultrasound when assessing for PCOS.