Ultrasound in Polycystic Ovarian Syndrome: What? When? How? Why? Who?

Abstract

Assessment of the ovarian morphology is one of the most commonly performed ultrasound examinations. Polycystic ovarian syndrome (PCOS) is a multifactorial, multifaceted, polygenic disorder with varying phenotypes. It defines a labyrinthine symptomatology including menstrual cycle irregularities, hormonal imbalance, and metabolic disturbance. Historically, this syndrome has been diagnosed clinically with supportive lab parameters. However, the role of ultrasound has mutated from identifying, to mis-defining and finally to re-classifying PCOS. At present it seems that the ultrasound identification of the ‘string of pearls’ has cemented this disease with a misleading name. A supposed increase in the detection of polycystic ovarian morphology on ultrasound has been accredited to advances in technology allowing better visualisation of the ovaries/stroma/follicles by higher frequency probes with the possibility of endovaginal imaging. Nevertheless, there is a disparity in what the ultrasound shows, how the clinician interprets the report, and what the patient understands about her diagnosis. Identification of the multifollicular ovary is still quite frequently ascribed to PCOS, while ovarian ultrasound remains ambiguous to the different phenotype of PCOS. Whether morphological disparities represent a normal variation in ovarian anatomy or true precursors of PCOS remains debatable. The absence of definition of a ‘normal’ ovary with respect to volume and follicular number, makes the diagnosis of PCOS more challenging.