[Value of MRI in the pre-operative diagnosis and classification of oblique vaginal septum syndrome].

To explore the role of MRI in the pre-operative diagnosis and classification of oblique vaginal septum syndrome (OVSS) . A retrospective analysis of the clinical records and pre-operative MRI images of 19 patients with surgery proved OVSS was carried out. Two experienced radiologists reviewed the pre-operative pelvic MRI of the 19 patients in consensus blind to the surgery results. Characteristics including malformations of the uterus, cervix and vagina, the diagnosis of the disorder and classification were evaluated. Pre-operative MRI diagnosis and classification were correlated with surgical findings. Mean age of onset of symptoms for the 19 patients was 15 years (ranged 9-25 years) , and mean age of menarche was 12 years. Ten patients suffered from dysmenorrhea or lower abdominal pain, 5 patients complained of vaginal discharge, 3 patients had a history of irregular menstruation, 1 patient suffered from primary infertility. All 19 patients showed uteri didelphys. Eighteen patients showed vaginal oblique septum.One patient showed cervical atresia.MRI was completely correlated with the surgery in the pre-operative diagnosis of OVSS. MRI classification was in line with surgery in 17 patients, including 9 patients with imperforate septum (typeⅠ) , 6 patients with perforate septum (type Ⅱ) , 1 patient with imperforate septum and cervical fistula (type Ⅲ) , and another one with cervical agenesis (type Ⅳ) . One case of type Ⅱ was misdiagnosed as type Ⅰ, another one of type Ⅰ was misdiagnosed as type Ⅲ. Pre-operative MRI classification was correlated with surgery in 17 out of 19 patients. Pre-operative MRI allows excellent manifestation and accurate diagnosis of OVSS, and could also facilitate the evaluation of the classification.