Dynamic MRI For Patients With Pelvic Organ Prolapse

Objective1. Probe to study the dynamic MRI characteristics of levator ani muscle and connective tissue of pelvic organ prolapse (POP), to establish a set of evaluation system with the use of dynamic MRI for the diagnosis of female pelvic ligaments and fascia weakness.2. Probe to study the displacement of pelvic organs under dynamic MRI, to establish a set of indexes for the diagnosis of POP with the use of dynamic MRI.3. Probe to study the different dynamic MRI characteristic pre and post-operative of POP group, and to study the imaging characteristic of mesh witch was inserted during reconstructive pelvic surgery. Probe to study whether it is a feasible way to evaluating the efficiency of reconstructive pelvic surgery.Methods and material1. Comparing the difference of levator hiatus size (LHS), iliococcygeus thickness (ICT), puborectalis thickness (PRT), iliococcygeus angle (ICA), levator plate angle (LPA) between POP group and the controls at rest and on maximal abdominal pressure.2. Comparing the displacement of pelvic organs at rest and on maximal abdominal pressure, compare the length of H-line and M-line at rest and on maximal abdominal pressure.3. Comparing the change of above imaging indexes pre and post-operative.4. Analyzing the imaging feature of implanted mesh.Results1. The POP group had larger LHS on maximal abdominal pressure (P=0.008). The thickness of ICT and right PRT of POP group were thinner both at rest and on maximal abdominal pressure, but the thickness of ICT and PRT didn't change after increasing abdominal pressure at both two groups.2. The POP group had larger ICA and LPA compared with the controls on maximal abdominal pressure. The angles of ICA and LPA changed distinctly at rest and on maximal abdominal pressure on POP group.3. The placements of bladder and uterus were lower. When on maximal abdominal pressure, bladder and uterus descent below the PCL line, and the controls changed slightly.4. The length of H-line was less than 5cm and the M-line was less than 2cm on both two groups at rest. But the length of H-line and M-line were increasing largely on maximal abdominal pressure on POP group.5. The pelvic organs returned to the normal position after surgery repair. LHS, ICA and LPA were smaller after surgery repair, but the thickness of ICT and PRT didn't change largely.6. The posterior two tapes could be recognized, but it was difficult to identify the anterior and the middle tapes.Conclusions1. It is a feasible way to study the structure and function of levator ani muscle using dynamic MRI, we can obtain the information of pelvic fascia and ligament.2. The mid-pubo line (MPL) was an imaging index for the analysis of perineum membrane and perineum body.3. Dynamic MR imaging can evaluate the degree of the prolapse pelvic organs, and the pubococcygeal line (PCL) was a feasible imaging index.4. Post-operative dynamic MRI is helpful in evaluating the efficiency of pelvic surgery repair.