Iniziativa Medica 1 article published in JoVE Medicine Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse Vittorio Piloni1, Mattia Bergamasco1, Andrea Chiapperin1 1Diagnostic Imaging Centre, Iniziativa Medica Here we present a protocol to standardize the measurement of the levator ani hiatus size by magnetic resonance imaging. The purpose is to extract biomechanical inferences from image analysis by comparing resting and straining values in patients of both sexes with pelvic prolapse, using consistent anatomical bony landmarks.