Cesarean section scar diverticulum evaluation by saline contrast‐enhanced magnetic resonance imaging: The relationship between variable parameters and longer menstrual bleeding

Aim This study was conducted to determine a more accurate imaging method for the diagnosis of cesarean scar diverticulum (CSD) and to identify the parameters of CSD strongly associated with prolonged menstrual bleeding. Methods We enrolled 282 women with a history of cesarean section (CS) who presented with prolonged menstrual bleeding between January 2012 and May 2015. Transvaginal ultrasound, general magnetic resonance imaging (MRI) and contrast-enhanced MRI were used to diagnose CSD. Five parameters were compared among the imaging modalities: length, width, depth and thickness of the remaining muscular layer (TRM) of CSD and the depth/TRM ratio. Correlation between the five parameters and days of menstrual bleeding was performed. Finally, multivariate analysis was used to determine the parameters associated with menstrual bleeding longer than 14 days. Results Contrast-enhanced MRI yielded greater length or width or thinner TRM of CSD compared with MRI and transvaginal ultrasound. CSD size did not significantly differ between women who had undergone one and two CSs. Correlation analysis revealed that CSD (P = 0.038) and TRM (P = 0.003) lengths were significantly associated with days of menstrual bleeding. Longer than 14 days of bleeding was defined by cut-off values of 2.15 mm for TRM and 13.85 mm for length. TRM and number of CSs were strongly associated with menstrual bleeding longer than 14 days. Conclusions CE-MRI is a relatively accurate and efficient imaging method for the diagnosis of CSD. A cut-off value of TRM of 2.15 mm is the most important parameter associated with menstrual bleeding longer than 14 days.