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MRI for pelvic floor dysfunction: can the strain phase be eliminated?
Sasha N Bhan1, Gevork N Mnatzakanian1, Rosane Nisenbaum2
1Department of Medical Imaging, St. Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, ON, M5B 1W8, Canada.
Purpose:
The purpose of the study was to determine if the strain phase of an MR defecography (MRD) protocol is redundant and can be eliminated without a loss of diagnostic information.
Materials And Methods:
Institutional review board approval was obtained and the requirement for informed consent was waived. A retrospective single-center review of 80 MRD examinations (68 female, 12 male, mean age 55 years old) was conducted. Two radiologists blinded to patient information evaluated in consensus the strain and evacuation phases separately and in a random order. Each phase was assessed for the presence and degree of posterior compartment descent, cystocele, urethral hypermobility, uterovaginal prolapse, rectocele, rectal intussusception, and enterocele. The degree of pelvic floor descent was compared using a paired t test and McNemar's test was used to compare the proportion of abnormal findings.
Results:
The evacuation phase identified all abnormalities identified on the strain phase and also identified both additional and more pronounced abnormalities, including an additional 34 cystoceles, 20 cases of urethral hypermobility, 13 uterovaginal prolapses, 36 rectoceles, 5 rectal intussusceptions, and 6 enteroceles (all p < 0.02). The mean posterior compartment descent was 24.1 mm greater on the evacuation phase than the strain phase (p < 0.0001).
Conclusion:
The strain phase is redundant and we propose that it can be eliminated from a routine MRD protocol. This will help streamline the examination, simplify patient instructions, and reduce both imaging and reporting time.
Insights
The strain phase of MR defecography (MRD) is redundant. Eliminating this phase streamlines the examination without losing diagnostic information, simplifying patient instructions and reducing reporting time.
Area of Science:
- Radiology
- Pelvic Floor Imaging
Background:
- MR defecography (MRD) is a key imaging modality for evaluating pelvic floor dysfunction.
- The standard MRD protocol includes both strain and evacuation phases.
Purpose of the Study:
- To determine if the strain phase of MRD is redundant.
- To assess if the strain phase can be eliminated without compromising diagnostic yield.
Main Methods:
- Retrospective review of 80 MRD examinations.
- Two blinded radiologists evaluated strain and evacuation phases for pelvic floor abnormalities.
- Statistical analysis using paired t test and McNemar's test.
Main Results:
- The evacuation phase identified all abnormalities seen in the strain phase.
- The evacuation phase revealed significantly more and pronounced abnormalities (e.g., cystocele, rectocele, enterocele).
- Mean posterior compartment descent was significantly greater during the evacuation phase (p < 0.0001).
Conclusions:
- The strain phase of MRD is diagnostically redundant.
- Eliminating the strain phase can streamline MRD protocols.
- This optimization reduces imaging and reporting time while simplifying patient instructions.
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