Objective: To correlate intravesical prostate protrusion (IPP) measured on transrectal ultrasonography (TRUS) with clinical data and to compare with the measurement on transabdominal ultranography (TAUS).
Methods: In 86 patients, TAUS was performed first without additional bladder filling, and bladder volume (BV, cc) and IPP (IA, mm) were measured. Then prostate volume (PV, cc), transitional volume (TV, cc), and IPP (IR, mm) were measured on TRUS. Examinations were randomly allocated to three examiners who had different degree of experience in TRUS. International Prostate Symptom Score (IPSS) was available in 58 of them and uroflowmetry were performed in 60. Pearson correlation coefficient (r), regression analysis, and Kruskal-Wallis test were used for statistics.
Results: IPSS showed significant correlation with IPP (p <.01) and TV (p <.05), and IR was better correlated than TV (r=0.395 vs 0.274): in regression analysis, R2=0.140 and 0.059, respectively. Of uroflowmetry data, residual volume showed significant correlation with IPP, PV, and TV (p <.01), and IR was better correlated than PV or TV (r=0.654, 0.529 and 0.517, respectively). Difference between IA and IR was 1.57±1.65 in mean (r=0.853) and showed weak positive correlation with bladder volume (r=0.25). However, it was not significantly affected by examiners’ experience in TRUS (p >.05).
Conclusions: IPP is correlated better with clinical data than PV or TV. There is no significant interexaminer variability or prominent effect of bladder volume in the difference between IPP by TRUS and by TAUS. IPP is recommended to be measured on routine TRUS examination.