Functional magnetic resonance imaging of the pelvic floor: Dynamic pressure and morphological changes in the levator ani muscle on straining demonstrated by MR-assisted biomechanical modelling - Tan, E; Lee, S-L; Gedroyc, W; Cornish, JA; Darzi, A; Yang, G-Z; Khullar, V; Tekkis, PP (GASTROENTEROLOGY, 2008)