Abstract: Objective: To investigate the manifestation and value of magnetic resonance imaging(MRI) in clinical diag-nosis of ectopic pregnancy(EP). Methods: Ultrasonic and clinical data in 58 cases of ectopic pregnancy confirmed by clini-cal or pathology in our hospital from July 2013 to April 2017 were collected and features of MR imaging were retrospectively analyzed. The diagnostic accuracy of ultrasound and MRI were calculated and compared. Results: Of all the 58 patients, the accuracy rate of MRI in diagnosis of ectopic pregnancy was 91.38%(53 cases), and was higher than that of ultrasound (77.59%, 45 cases)（P<0.05）. MRI could show complete gestational sac and cystic, solid-cystic or heterogeneous mass imaging in 56 cases. The mass of pregnancy sac was round or oval and the boundary with surrounding tissue was clear on MR imaging. The high signal in T1W imaging was related to the hemorrhage of gestational sac. Two cases of ruptured pregnancy sac showed imaging with irregular mass, heterogeneous SI in T1WI and T2WI, and signal of scattered or patchy bleeding was found in the mass, with high SI in T1WI and slightly higher SI in T2WI; imaging of hemorrhage in gestational sac and pelvic hemorrhage were the characteristic features. Conclusions: MRI can clearly reveal the anatomic relationship between embryo sac and its surrounding structures, identifying the location and showing the implantation of gestational sac clearly. For cases of ectopic pregnancy which are difficult to diagnose by ultrasound, MRI examination could be performed, which is of important reference value for evaluation of the disease and selection of treatment options.

Key words: Magnetic resonance imaging, Ectopic pregnancy, Hemorrhage, Embryo sac