Test-retest reliability of clitoral blood flow measurements using color Doppler ultrasonography at rest and after a pelvic floor contraction task in healthy adult women

Abstract

Aims: Test-retest reliability assessment of the dorsal clitoral artery's blood flow at rest and after muscle activation has never been documented. If this outcome measure is to be used in conditions impeding vascularity, it requires a psychometric evaluation. The aim of this study was to assess the inter-session test-retest reliability of clitoral blood flow in healthy women using color Doppler ultrasonography at rest and after a pelvic floor muscle (PFM) contraction task.

Methods: Two assessment sessions were conducted using a clinical ultrasound system. Clitoral blood flow measurements were repeated at rest and after a PFM contraction task. Measurements of the peak systolic velocity (PSV), time-averaged maximum velocity (TAMX), end-diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI) were taken. The test-retest reliability was assessed using paired t-test, intraclass correlation coefficient (ICC), and Bland-Altman plots.

Results: For reliability at rest, ICC values were 0.95 for PSV, 0.87 for TAMX, and 0.67 for both PI and RI. The variability between measurements, as per Bland-Altman plots, was small for PSV, TAMX, and RI and acceptable for PI. For reliability after the PFM contractions task, ICC values were 0.85 for PSV, 0.77 for TAMX, 0.79 for PI, and 0.81 for RI. The variability between measurements was small for PSV and RI and acceptable for TAMX and PI. EDV parameter did not perform as well in both conditions.

Conclusions: Assessment of the clitoral blood flow with color Doppler ultrasound is reliable at rest and after a PFM contraction task.

Keywords: Doppler; dorsal clitoral artery; imaging; pelvic floor contractions; ultrasound.