Diagnostic value of transvaginal three-dimensional ultrasonography combined with superb microvascular imaging for endometrial polyps

AimsTo evaluate the diagnostic value of transvaginal three-dimensional ultrasonography combined with superb microvascular imaging (SMI) for the preoperative detection of endometrial polyps, and to determine whether multimodal integration improves detection yield, diagnostic confidence, or recognition of diagnostically challenging lesions compared to morphology-based imaging alone.MethodsIn this retrospective observational study, we reviewed 203 consecutive patients with suspected endometrial polyps who underwent evaluation at the Central Hospital of China Railway 17th Bureau Group Co., Ltd. between July 2025 and January 2026. All patients underwent conventional ultrasonography, transvaginal three-dimensional ultrasonography (3D-TVS), and SMI before hysteroscopic pathologic confirmation, which was used as the reference standard. Diagnostic performance was compared among different imaging strategies, including 3D-TVS alone, SMI alone, conventional ultrasonography combined with SMI, and 3D-TVS combined with SMI. The primary endpoint was preoperative detection yield of endometrial polyps.ResultsCompared to conventional ultrasonography, 3D-TVS alone did not significantly improve the overall preoperative detection rate of endometrial polyps, whereas SMI alone significantly increased detection rate (P<0.05). The addition of SMI significantly improved detection when combined with conventional ultrasonography or 3D-TVS (both P<0.001), with 3D-TVS + SMI showing the highest overall diagnostic performance. Conventional ultrasonography and 3D-TVS more readily detected larger, solitary, pedunculated lesions with well-defined margins, whereas missed lesions were more frequently characterized by small size, multiplicity, sessile morphology, lower uterine segment location, intrauterine device use/history, heterogeneous endometrium, or acoustic artifacts (all P<0.05). SMI-based recognition was strongly associated with the presence of intralesional blood flow, central feeding vessels, branching vascular patterns, continuous vascular pedicles, and higher microvascular indices (all P<0.001). Multivariable analysis identified lesion size <15 mm, sessile morphology, acoustic artifact, absence of vascular pedicles, low microvascular density, and failure of coronal plane reconstruction as independent predictors of missed diagnosis (all P<0.05).ConclusionTransvaginal 3D ultrasonography combined with SMI significantly improves the preoperative detection of endometrial polyps, particularly for diagnostically challenging lesions.