Dynamic MR defecography with an open-configuration, low-field, tilting MR system in patients with pelvic floor disorders.

Purpose. This study was undertaken to explore the capabilities of an open-confi guration, low-field, tilting, magnetic resonance (MR) system for investigating pelvic floor disorders and to compare the results obtained with the patient in the semiorthostatic and supine positions. Materials and methods. Eighteen female patients with a diagnosis of pelvic fl oor disorder (physical examination and conventional defecography) underwent dynamic MR defecography (MRD) with a 0.25-T tilting MR system (G-scan, Esaote). Images were obtained after administration of contrast agent into the rectum, bladder and vagina in both the orthostatic and supine positions. Three-dimensional T2-weighted hybrid contrast-enhanced (HYCE) sequences and dynamic T1-weighted gradientecho (GRE) sequences were acquired at rest, during maximal contraction of the anal sphincter, straining and defecation. Results. Good image quality was obtained in 15/18 patients; three presented severe artefacts due to motion, and three had incontinence, which hampered the functional studies. Better anatomical detail was obtained with MRD compared with conventional defecography. Three prolapses were observed in the semiorthostatic position only, and seven were found to be more severe in the orthostatic than in the supine position. Conclusions. Dynamic MRD with an open-confi guration,low-fi eld, tilting MR system is a feasible and promising tool for studying the pelvic fl oor. Larger series are necessary to assess its real diagnostic value.