The repeatability of measurements of male pelvic floor anatomy and function made from transperineal ultrasound images of healthy men and those before and after prostatectomy.

AIMS

To investigate the inter- and intratester repeatability of measurement of the location and displacement of five pelvic landmarks related to pelvic floor muscles with transperineal ultrasound (TPUS) imaging recorded from healthy men and men before and after prostatectomy.

METHODS

TPUS images were selected from four different participant groups: healthy men, men awaiting prostatectomy, men 2 weeks after prostatectomy, and men 12 months after prostatectomy. On two separate occasions, two assessors with different levels of experience performed analysis of location and displacement of five pelvic landmarks in images made at rest and during voluntary contraction. A two-way mixed effects, single measurement, absolute agreement intraclass correlation coefficient (ICC) was used to investigate the repeatability.

RESULTS

Intertester reliability of all locations at rest for all groups was excellent (ICCs > 0.8) except for the craniocaudal coordinate of the ventral urethrovesical junction for men 2 weeks postprostatectomy and the anorectal junction for men with a cancerous prostate. Intertester reliability of the measurement of landmark displacement was acceptable (>0.5) for the dorsoventral axis of motion but not for the craniocaudal axis of motion for all landmarks across all groups. The more experienced assessor was consistently more repeatable. More deeply placed landmarks were more often excluded from analysis and had poorer reliability.

CONCLUSIONS

Analysis of TPUS images across clinical groups is repeatable for both location and displacement of pelvic landmarks related to pelvic floor muscles when measures are made twice. Analysis experience, landmark depth and optimization of ultrasound settings appear to be important factors in reliability.