Sonourethrography in evaluation of anterior urethral abnormalities and comparison with retrograde urethrogram

Abstract

Background: Sonourethrography (SUG) offers important technical advantages over conventional retrograde urethrography (RGU) by estimating the length of strictures, degree of spongiofibrosis which could be more informative in making decisions about management. The present study is intended to evaluate the role of SUG in investigating anterior urethral abnormalities and comparison of SUG with RGU and per-operative (PER-OP) findings. Methods: All 31 patients had undergone RGU first and then followed by SUG. The findings of both examinations were tabulated and compared with per-operative findings. Results: Total number of pathologies detected in RGU, SUG and PER-OP are 45, 53 and 53, respectively. In detecting strictures, the overall sensitivity is 97% and 100%, specificity 50% and 66%, positive predictive value 94% and 97%, negative predictive value 66.6% and 100%, accuracy is 92% and 97% and Cohen's Kappa is 0.53 and 0.78 for RGU and SUG, respectively. The mean length of stricture calculated on SUG was closer to that of surgery when compared with RGU. The percentage sensitivity and accuracy of SUG in detecting spongiofibrosis is 94.7%. The accuracy of RGU and SUG in detecting urethritis is 47% and 94%. Conclusions: SUG gives more accurate information about stricture length and periurethral fibrosis, thus is more useful to determine the suitable operative procedure.