Use of Three-dimensional US for Troubleshooting in Gynecologic Imaging.

Three-dimensional (3D) US is an invaluable, rapidly evolving tool in gynecologic imaging. This examination, comparable to CT and MRI, enables volumetric data to be obtained, reconstructed, and displayed in multiple planes. It also enables the sonologist to better understand the spatial and anatomic relationships of uterine and adnexal abnormalities, thereby improving diagnostic accuracy. Three-dimensional US can be performed routinely following a two-dimensional (2D) transabdominal and/or transvaginal US examination or as an adjunctive troubleshooting technique, since no additional patient preparation is necessary. Performing additional 3D imaging adds only a few minutes to the original examination time while yielding information that is useful for reaching a diagnosis. Multiplanar reconstruction of volumetric data in the midcoronal plane is the cornerstone for diagnosing congenital uterine anomalies, as it allows visualization of the external uterine contour and shape of the endometrial cavity. It also enables early detection of endomyometrial junction abnormalities such as adenomyosis and focal adenomyomas. Combined with 3D power Doppler imaging, 3D US may help differentiate endometrial polyps, submucosal fibroids, endometrial hyperplasia, and endometrial carcinoma, aiding in clinical decision making. This examination also facilitates accurate localization of fibroids relative to the endometrial cavity and serosal surface of the uterus. The authors review the technique for acquisition of 3D volume datasets, image reconstruction, and new software techniques for data postprocessing that are applicable to gynecologic imaging. In addition, scenarios in which the addition of 3D US provides an advantage over routine 2D US, including imaging of congenital uterine anomalies, fibroid localization, and differentiation of endometrial diseases, are highlighted. ©RSNA, 2025 Supplemental material is available for this article.