[Relationship between sonographic endometrial images and endometrial histology during the secretory phase]

Transvaginal sonographic endometrial images and endometrial biopsies were obtained during the luteal phase (L5-L10) from 31 patients with normal menstrual cycles. The Hyperechoic Endometrial Area (HEA) ratio was used as the index of sonographic endometrial dating, and 12 glandular and/or stromal parameters were used as the index of histological endometrial dating. The day of ovulation was determined with sequential transvaginal sonography. In 20 patients with a typical sonographic image, 80% of the HEA ratio was equal to L6 based on the histological endometrial dating, and 90% was equal to L9. These results suggested the efficacy of the sonographic endometrial dating. The remaining 11 patients with an atypical sonographic endometrial image were classified into 3 groups (hyperechoic, spotted and hypoechoic type). Two characteristic features, delayed glandular element and increased stromal cell density, were observed in the hyperechoic group. On the other hand, dissociation between glandular and stromal dating was observed in the spotted group. Hypoplastic glands and insufficient secretion were characteristic of the hypoechoic group. These results show that sonographic endometrial dating has clinical efficacy. This dating has enough coincidence with endometrial histology. Moreover, two advantages were recognized in the sonographic dating over the histological dating. One is the non-invasive examination, and the other is the real-time evaluation of the endometrium.