INTRODUCTION: Uterine fibroid (UF) stiffness may contribute to tumor growth, symptom severity, and treatment response. Shear wave elastography (SWE) is a noninvasive, quantitative ultrasound method for measuring tissue stiffness, but it lacks standardization in gynecologic applications. This pilot study aimed to 1) develop a standardized transvaginal SWE protocol to assess myometrial and UF stiffness; 2) evaluate interrater and test–retest reliability; and 3) determine whether stiffness varies by menstrual phase. METHODS: In this prospective pilot study (January to September 2024), 27 women (17 with UFs, 10 without) were enrolled. Each underwent transvaginal SWE imaging during both the follicular and luteal phases of their menstrual cycle. Shear wave elastography values were independently calculated by two raters, with one rater repeating measurements after a 3-month interval to assess reliability. RESULTS: Fifty-one myometrial and 38 UF measurements demonstrated excellent interrater reliability (r=0.97, P <.001). Test–retest reliability was similarly high for 50 myometrial and 42 UF measurements (r=0.95 and r=0.98, respectively; P <.001). Uterine fibroids were significantly stiffer than the surrounding myometrium (median 52.4 versus 32.9 kPa, P <.001). Myometrial stiffness did not differ significantly between women with and without UFs ( P =.6), and menstrual phase had no effect on stiffness values. CONCLUSIONS/IMPLICATIONS: This pilot study establishes a reliable, reproducible protocol for transvaginal SWE in measuring uterine myometrial and UF tissue stiffness. These findings support its feasibility and potential value in personalized assessment and monitoring of UFs in clinical practice.
Ryles et al. (2026) studied this question.