This document discusses the use of transvaginal ultrasound (TVS) to diagnose Polycystic Ovarian Syndrome (PCOS). It states that TVS can identify PCOS in approximately 75% of clinically diagnosed cases. Key ultrasound criteria for diagnosing PCOS include an antral follicle count (AFC) of more than 12 follicles sized 2-9mm in one or both ovaries, or an ovarian volume greater than 10cm3 with no follicles over 10mm. Recent guidelines consider an AFC over 25 as meeting the ultrasound criteria for a PCOS diagnosis. The document provides references and information for patients on infertility and contacting a doctor for related queries.