Abstract
A study was conducted to determine whether ultrasonographic detection of urinary retention is associated with clinically suspected lower urinary tract infection (UTI). During a 6-month period (January-June 2007), women aged >16 years who presented to the emergency department of Queen Elizabeth Hospital with clinical symptoms of lower UTI were enrolled. Totally 187 patients participated and completed the study. The mean age was 50.8 ± 21.5 years. Sixty-eight (36.4%) had positive urine culture while 119 (63.6%) were negative. Defining a significant residual urine volume of greater than 50 ml had low sensitivity (17.7%) and high specificity (100%) for the detection of UTI. However, when taking into account those of smaller residual urine volume (less than 50 ml), overall 37.6% of the patients with UTI had detectable residual urine in the bladder and no significant residual urine was detected in all culture-negative patients.