Plicae Palmatae on MR in Uterus Didelphys: the Incidence and Morphological Characteristics

Objective: To investigate the incidence of plicae palmatae in uterus didelphys and its morphological characteristics on MR imaging. Methods: We retrospectively collected 37 consecutive female pelvic MR images diagnosed with uterus didelphys between August 2012 and November 2020. Patients with the following conditions were excluded: (a) repeated examination; (b) poor image quality; (c) cervical disease. Axial and coronal T2-weight images and axial three-dimensional (3D) volumetric isotropic T2-weighted acquisition (VISTA) were used to evaluate the ridge of plicae palmatae (RPP). A multiplanar reformation of the cervical axis from 3D-VISTA sequence was performed to measure the height and width of RPP. Non-normal variables based on the Kruskal-Wallis H test was used for statistical analysis. A two-tailed test where P < 0.05 was considered statistically significant. Results: Twenty-six cases were finally included in the statistics. The average age was 25.7±9.0 years (range, 10-45 years). RPP was observed on both cervices in 16 patients (61.5%), only on the left cervix in 3 patients (11.5%), and only on the right cervix in 4 patients (15.4%). There were 3 cases with no RPP observed in any of their cervix (11.5%).All RPP appear symmetrically on the anterior and posterior walls of the cervix. There was no statistically significant difference in height, width, and height/width of the RPP in the left and right cervix (p＞0.05). Conclusions: RPP is encountered in 88.5% patients with duplicated uterine cervices in our cohort. This incidence is similar to that reported in women with normal uterus of reproductive age.