UW Emergency Radiology
US of the Normal Endometrium
Classification |
Thickness (mm) |
Notes |
Menstrual phase: |
||
| Menstrual (days 1 – 4) | 4 – 7 | Mildly echogenic |
| Proliferative (days 5 – 13) | 4.5 – 8 | Mildly echogenic |
| Ovulatory (days 13 – 16) | hypoechoic inner layer, hyperechoic periphery | |
| Secretory (days 16 – 28) | 6 – 12 | More uniform, gradually decreasing echotexture |
Postmenopausal |
1 – 2 | |
| Postmenopausal with bleeding | <5 | Consider biopsy if greater than 4 -5 mm |
| Postmenopausal without bleeding | <8 | Consider biopsy if >8 mm |
Hormone replacement |
||
| Sequential estrogen/progesterone | Cyclical changes | Similar to premenopausal appearance (above) |
| Continuous estrogen/progesterone | <5 | |
| Tamoxifen | >8mm in half patients | ~1% risk endometrial carcinoma |
References:
Langer, J. E., et al. (2012). “Imaging of the female pelvis through the life cycle.” Radiographics 32(6): 1575-1597.
Fleischer, A. C. (1998). “Transvaginal sonography of endometrial disorders: an overview.” Radiographics 18(4): 923-930.