Objective To explore the MSCT and MRI characteristics of hydrosalpinx.Methods The CT and MRI findings of 28 patients with hydrosalpinx confirmed by surgery and pathology were retrospectively studied.Before operation,the plain and contrast enhanced CT in 25 patients and the plain and contrast enhanced MRI in 3 had been carried out.Results 1 9 patients with unilateral hydrosalpinx (12 on the left and 7 on the right side)and 9 patients with bilateral hydrosalpinx were found.Both CT and MRI images showed the cystic mass with different forms in annex area,including botuliform changes in 1 6 patients,beaded form in 9,polycystic changes in 8 and retort-like changes in 4.The low density as water on plain CT,and the low signal on T1 WI and high signal on T2 WI were showed.The cystic walls were significantly enhanced without nodules.If there is septum,mild enhancement was also found.14 patients with chronic salpingitis,2 with fascial thickening,3 with uterine fibroid and 1 7 with pelvic fluid.Conclusion CT and MRI findings of hydrosalpinx are characteristic.