Saddlebag bladder sign (endopelvic fascial defect)

The saddlebag bladder sign refers to the appearance caused on axial pelvic MR images by posterior drooping of the posterolateral wall(s) of the urinary bladder, due to loss of integrity of the lateral level 2 endopelvic fascia. If combined with a defect of the puborectalis muscle on the ipsilateral side, there may also be a loss of the normal H or W shape of the middle third of the vagina.