Evaluation of the relationship between bladder debris in ultrasonography and urine analysis results in children with suspected urinary system infection

Introduction: The aim of this study was to investigate the relationship between the presence of debris in the bladder and symptoms, urine analysis results and the role of predicting urine culture positivity in children presenting with suspected urinary tract infection. Our secondary aim is to evaluate the quantitative value of bladder debris by ultrasonography and to support the symptoms and urine analysis results in the diagnosis of urinary tract infection. Thus, we anticipate that unnecessary antibiotherapy, multiplication of drug resistant microorganisms and drug costs would be reduced, with the selection of patients who really need treatment without time wasting until urine culture results by the use of ultrasonography. Methods: The study included 125 children aged between 3-17 years presenting with urinary tract infection symptoms such as dysuria, urgency, subprapubic pain between March 2019 and November 2019 at Akdeniz University Hospital. A detailed patient follow-up form including symptoms, background, family history, physical and ultrasonographic findings was completed. A single physician recorded the gray-scale images of the patients by ultrasound over the filled bladder within 24 hours of admission, both as a video and an image. Pre- and post-mictional bladder volume indices, post-mictional residual volume indices, mean bladder wall thickness, subcutaneous to parietal peritoneum distance were measured. Patients with shadow in ultrasonography suspending stones were excluded from the study. Presence or absence of bladder debris was reported by the original reading radiologist on all ultrasound images/videos, including a semi-objective determination of the bladder debris severity (mild, moderate, severe, or no debris). From the recorded images, the mean echogenicity value (MEV) was calculated over the region of interest (bladder) using Adobe Photoshop Cs6 program. All images, measurements and drawings were checked by two specialist radiologists experienced in the field of ultrasonography for at least 10 years. Results: Urine culture was positive in 16% (n = 20) and bladder debris was detected in 42.4% (n = 53) of all patients. Bladder debris was observed in 85% (n = 17) of the patients with urine culture positive. Between the urine culture positive and negative groups, Postmictional Bladder Volume Index (p=0.03), Residual Volume Index (p=0.001), Postmictional Residual Urine (p<0.001), the semi-objective debris (p<0.001), Histogram Grey Scale(Gs) MEV (p=0.01) were different significantly. Median values of histogram Gs MEV coefficient, were 41.30 in urine culture negative group and 69.30 in urine culture positive group. When the presence of debris was evaluated according to the threshold value of MEV 71.00 obtained by using ROC curves, urine culture was positive in 10(55.5% ) of 18 patients. Histogram Gs MEV cut-off value was 71.00 and above, according to the likelihood ratio (LR +/-) of detecting urine culture positivity increased by 6.5 times moreover if cut-off value was below 71.00, it was found to be reduced by 0.54 times. Histogram Gs MEV value and its relationship with subjective debris scoring (none, mild, moderate, severe) was evaluated with Kruskal-Wallis test. When the semiobjective severity of debris (no debris, mild, moderate, heavy) increased, the debris MEV obtained from the histogram increased significantly (p<0.01). For the semiobjective evaluation, in the presence of moderate-severe debris, the probability of detecting urine culture positivity according to the likelihood ratio (LR +/-) increased 3.8 fold, whereas it decreased by 0.52 times in the absence of medium-heavy debris. Histogram Gs MEV was found to be effective in showing 100% urine culture positivity together with nitrite positivity. When multivariate logistic regression test was performed with classical urine analysis findings (pyuria, leukocyte esterase, nitrit) Bladder Debris Histogram Gs OED could be used as an independent diagnostic tool. Conclusions: The bladder debris is frequently reported by radiologists, and there are few studies in the literature investigating its clinical significance. Our study revealed that the presence of bladder debris by ultrasound in symptomatic patients supports the early diagnosis of pediatric urinary tract infection while awaiting the urine culture results. In addition to the use of the histogram in other internal branches of health, it was shown that the coefficients obtained from the histogram had a significant relationship with urine results, and the use of histograms in the diagnosis of pediatric urinary tract infections contributed to the literature.