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

MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

Introduction. Functional disorders of the pelvic floor represent have a significant impact on the quality of life. The advent of open-configuration systems allowed for the evaluation of defecation with MR imaging in sitting position. The purpose of the present study is to compare the results of static and dynamic pelvic MR performed in supine position versus sitting position, using a new MR prototype machine, in the diagnosis of pelvic floor descent. Materials and Methods. Thirty-one patients with pelvic floor disorders were enrolled, and underwent MR Defecography in supine position with 1.5 T closed magnet (MAGNETOM Symphony, Siemens, Germany) and in sitting position with a 0.25-Tesla open magnet system (G-Scan ESAOTE, Italy). Results. In rest and squeezing phases, positions of bladder, vagina, and ARJ were significantly different when the patient was imaged in supine versus sitting position. In the defecation phase, a significant difference for the bladder and vagina position was detected between the two exams whereas a significant difference for the ARJ was not found. A statistically significant difference exists when the pelvic floor descent is evaluated in sitting versus supine position. Conclusion. Our results show that MR Defecography in sitting position may represent a useful tool to correctly diagnose and grade the pelvic organ descent.

Medical and surgical management of pelvic floor disorders affecting defecation

Pelvic floor disorders that affect stool evacuation include structural (for example, rectocele) and functional disorders (for example, dyssynergic defecation (DD)). Meticulous history, digital rectal examination (DRE), and physiological tests such as anorectal manometry, colonic transit study, balloon expulsion, and imaging studies such as anal ultrasound, defecography, and static and dynamic magnetic resonance imaging (MRI) can facilitate an objective diagnosis and optimal treatment. Management consists of education and counseling regarding bowel function, diet, laxatives, most importantly behavioral and biofeedback therapies, and finally surgery. Randomized clinical trials have established that biofeedback therapy is effective in treating DD. Because DD may coexist with conditions such as solitary rectal ulcer syndrome (SRUS) and rectocele, before considering surgery, biofeedback therapy should be tried and an accurate assessment of the entire pelvis and its function should be performed. Several surgical approaches have been advocated for the treatment of pelvic floor disorders including open, laparoscopic, and transabdominal approach, stapled transanal rectal resection, and robotic colon and rectal resections. However, there is lack of well-controlled randomized studies and the efficacy of these surgical procedures remains to be established.

Pelvic floor imaging: comparison between magnetic resonance imaging and conventional defecography in studying outlet obstruction syndrome

PURPOSE

This study prospectively compared the diagnostic capabilities of magnetic resonance (MR) imaging with conventional defecography (CD) in outlet obstruction syndrome.

MATERIALS AND METHODS

Nineteen consecutive patients with clinical symptoms of outlet obstruction underwent pelvic MR examination. The MR imaging protocol included static T2-weighted fast spin-echo (FSE) images in the sagittal, axial and coronal planes; dynamic midsagittal T2-weighted single-shot (SS)-FSE and fast imaging employing steady-state acquisition (FIESTA) cine images during contraction, rest, straining and defecation. MR images (including and then excluding the evacuation phase) were compared with CD, which is considered the reference standard.

RESULTS

Comparison between CD and MR with evacuation phase (MRWEP) showed no significant differences in sphincter hypotonia, dyssynergia, rectocele or rectal prolapse and significant differences in descending perineum. Comparison between CD and MR without evacuation phase (MRWOEP) showed no significant differences in sphincter hypotonia, dyssynergia or enterocele but significant differences in rectocele, rectal prolapse and descending perineum. Comparison between MRWEP and MRWOEP showed no significant differences in sphincter hypotonia, dyssynergia, enterocele or descending perineum but significant differences in rectocele, rectal prolapse, peritoneocele, cervical cystoptosis and hysteroptosis.

CONCLUSIONS

MR imaging provides morphological and functional study of pelvic floor structures and may offer an imaging tool complementary to CD in multicompartment evaluation of the pelvis. An evacuation phase is mandatory.