Figure 1

Longitudinal ultrasound images demonstrate the endometrial pattern. (A) Triple-line pattern: hypoechoic endometrium with well-defined hyperechoic outer walls and a central echogenic line; (B) No-triple line pattern: isoechoic endometrium with poorly defined outer walls and central echogenic line; (C) No-triple line pattern: homogeneous hyperechoic endometrium.