Cyclic endometrial changes: US assessment with histologic correlation.

The ultrasonographic (US) appearance of the endometrium was evaluated in 80 patients, and the US diagnosis of endometrial stage was compared with that from same-day endometrial biopsy specimens. The US signs of proliferative endometrium included triple-line sign, hypoechoic function layer, and minimal or absent posterior acoustic enhancement. The signs of secretory endometrium included absent triple-line sign, hyperechoic functional layer, and strong posterior acoustic enhancement. When all of these US signs were clearly depicted in combination, the accuracy of diagnosis was 93% (30 patients). The accuracy of diagnosis for all patients in the study was 76% (73 patients). The relative distributions of each US sign in proliferative and secretory endometrium were compared. Despite complicating extrinsic factors such as uterine leiomyomas and intrinsic factors such as the transition period between endometrial phases, US staging of the endometrium is a useful diagnostic technique that allows serial examinations of the endometrium.