“Bridging Vascular Sign” in the MR Diagnosis of Exophytic Uterine Leiomyoma

Purpose: The purpose of this study was to evaluate the usefulness of the “bridging vascular sign” in the diagnosis of an exophytic uterine leiomyoma and differentiation of a uterine leiomyoma from some other mass arising in the adnexa on pelvic MRI. Method: Of 52 women with a pelvic mass in whom pelvic MRI was performed to determine its origin, 26 women with surgicopathologically proven leiomyomas were included in this study. The other 26 women were proved to have indeterminate adnexal masses such as tuboovarian abscess, endometrioma, fibroma, etc. To obtain axial/sagittal T2-weighted and pre-/postcontrast T1-weighted images, a 1.5 T unit was used. Positive bridging vascular sign was defined as the presence of curvilinear tortuous signal void vascular structures crossing and/or between the uterus and the pelvic mass. For the presence or absence of this sign, the percentages of patients in each group were calculated and compared. Results: Bridging vascular sign was present in 20 (76.9%) of 26 cases of leiomyomas but in no cases of other adnexal masses. Only exophytic uterine leiomyomas had this sign. Conclusion: Bridging vascular sign on MRI may be a useful radiologic sign in the diagnosis and differentiation of an exophytic uterine leiomyoma from some other mass arising in the adnexa.