Pubococcygeal Line Versus H-line as MR Defecography Reference for Bladder Descent

Area of Science:

• Pelvic floor imaging
• Radiological assessment of pelvic organ prolapse (POP)
• Diagnostic accuracy of imaging biomarkers

Background:

• Magnetic resonance defecography (MRD) is crucial for evaluating pelvic floor function and diagnosing POP.
• Current diagnostic methods rely on landmarks like the pubococcygeal line (PCL) to assess bladder descent.
• There is a need for accurate and reliable imaging markers to quantify bladder descent.

Purpose of the Study:

• To evaluate the diagnostic accuracy of the H-line compared to the PCL in detecting bladder descent via MR defecography.
• To determine if the H-line can serve as a reliable landmark for diagnosing clinically significant bladder descent.

Main Methods:

• Retrospective cohort study of patients undergoing MR defecography with moderate to severe cystocele.
• Measurements included bladder base distance to genital hiatus (GH), PCL, and H-line (minimal levator hiatus line).
• Bladder descent was defined as the bladder base reaching within 1 cm of the GH.

Main Results:

• Seventy subjects were analyzed; 30 had clinically significant bladder descent.
• Bladder descent correlated with older age, increased parity, and lower H-line measurements at rest and evacuation.
• Receiver operating characteristic analysis showed the H-line (AUC 0.82) and PCL (AUC 0.86) were both effective, with specific thresholds identified.

Conclusions:

• The H-line, representing the minimal levator hiatus plane, is a reliable landmark for diagnosing bladder descent in MR defecography.
• The H-line provides valuable data for assessing pelvic floor support and diagnosing POP.
• MR defecography utilizing the H-line offers a robust method for POP evaluation.