Strain phase of MRI for pelvic floor dysfunction can be eliminated
Pelvic floor disorders –incontinence, pelvic pain, dysfunctional defecation, and pelvic organ prolapse – affect nearly one fourth of all women living in the United States, and up to half of all women aged 80 and older. Diagnostic imaging is able to confirm and characterize clinically suspected abnormalities as well as identifying unsuspected concomitant pelvic floor defects.
MR defecography, which provides structural and functional assessment of the pelvic floor, has been shown to provide information that leads to changes in patient management. The examination typically includes three to four dynamic phases that are performed by the patient. Canadian researchers at St. Michael’s Hospital of the University of Toronto in Ontario suggest that one of these segments – the strain phase – is redundant. In an article published in the February issue of Abdominal Radiology, they explain why the strain phase is redundant and could be eliminated from a MR defecography exam for most patients.
Radiologists at the hospital conducted a retrospective study of 80 patients who had a MR defecography exam performed between May 2011 and August 2014 to determine if the strain phase of the protocol could be eliminated without the loss of diagnostic information. The patient cohort ranged in age from 22 to 86 years, and included 12 men. The majority of clinical indications included constipation/incomplete evacuation (49%), fecal incontinence (26%), and prolapse (15%).
Two radiologists working in concensus evaluated the exams, making an assessment of the rest, strain and evacuation phases. Images were assessed for the presence and degree of pelvic floor descent, cystocele, urethal hypermobility, uterovaginal prolapse, rectocele, and intussuception. The radiologists determined that all abnormalities detected on the strain phase were also detected on the evacuation phase, with the exception of fecal incontinence. The evacuation phase identified additional abnormalities as well as more pronounced ones.
Co-author Errol Colak, M.D., assistant professor of radiology, and colleagues suggest that eliminating the strain phase of a MR defecography protocol would reduce imaging time and simplify patient instructions. Although acknowledging that the strain phase of MR defecography does allow for the assessment of urinary and fecal incontinence, they conclude that “it is redundant, and can be eliminated without the loss of diagnostic information, which will help streamline the examination, simplify patient instructions, and reduce both imaging and reporting time.”
REFERENCE
- Bhan SN, Mnatzakanian GN, Nisenbaum R, et al. MRI for pelvic floor dysfunction: can the strain phase be eliminated? Abdom Radiol. 2016;41(2):215-220.