Voiding Cystourethrography Examinations Research Articles

Voiding Sistoüretrogram ile Tanı Konulan Vezikoüreteral Reflü'nün Saptanmasında Dinamik Böbrek Sintigrafisinin Rolü

Aims: This study aims to evaluate the role of standardized dynamic renal scintigraphy (DRS) in recognizing vesicoureteral reflux (VUR) in patients detected with VUR by voiding cystourethrography (VCUG). Methods: The data of all pediatric patients who underwent both VCUG and DRS [technetium-99m diethylenetriamine pentaacetic acid (Tc-99m DTPA) or technetium-99m mercaptoacetyltriglycine dynamic renal scintigraphy (Tc-99m MAG-3)] in our hospital between 2013 and 2022 were retrospectively reviewed. Tc-99m MAG-3 was used in infants and Tc-99m DTPA radiopharmaceutical in children over one year old. According to VCUG findings, VUR grades were grouped as grade I-II-III low-grade VUR and IV-V high-grade VUR. The role of DRS in detecting VUR in both low and high-VUR-grade groups was evaluated. Results: A total of 56 patients (and 69 renal units), 23 girls (%41.1), and 33 boys (%68.9) were included in this study. The median value of the time elapsed between the DRS and VCUG examinations was nine days. According to VCUG, VUR was grade I in five renal units, grade II in 19 renal units, grade III in six renal units, grade IV in six renal units, and grade V in 33 renal units. DRS detected VUR in two of 30 renal units (%6.7) in the low VUR grade group. On the other hand, VUR was observed with DRS in 27 of 39 renal units (%69.2) in the high VUR grade group. Conclusions: Standardized DRS shows very low sensitivity in recognizing low-grade VUR, and its performance in detecting high-grade VUR is comparatively better. Raising awareness among clinicians that VUR can be observed with standardized DRS will benefit the patient in terms of early detection of accompanying VUR pathologies.

Evaluation of the Relationship of the Time of Vesicoureteral Reflux Between Renal Scar Development and Endoscopic Treatment Success in Early Childhood

INTRODUCTION: Vesicoureteral reflux (VUR) is an important cause of urinary tract infection and chronic renal disease. Voiding cystourethrography (VCUG) is the gold standard diagnostic test in the diagnosis of VUR. In recent years, new parameters related to VCUG have been more objectively studied to evaluate the clinical prognosis. It is aimed to evaluate the effect of reflux time in primary VUR in terms of predicting endoscopic treatment success and treatment timing in VUR management. METHOD: In our study, the records and imaging findings of children with primary VUR who underwent VCUG examination between 2012 and 2019, who were treated with endoscopic injections, were retrospectively reviewed. Forty one children (67 renal units) were included in our study. Patients with preoperative VCUG, urinary ultrasonography, dimercaptosuccinic acid (DMSA) renal scan, and post-operative control VCUG were included in this study. RESULTS: Patients with preoperative VUR grade 1-2 were divided into two groups as “low grade” and patients with stage 3-4-5 as “high grade”. In the general patient population, endoscopic success rates in terms of renal unit deficit were found to be 46.3% (31/67). When the subgroup was analyzed, the endoscopic treatment success rate was 72.2% (13/18) in the low-grade group, versus 36.7% (18/49) in the high-grade group (p = 0.010). In the multivariate logistic regression analysis performed to identify independent predictors of scarring, reflux degree and reflux time were found to be independent predictors of scarring. CONCLUSION: In our study, we found that in VCUG evaluated preoperatively, VUR time as well as VUR grade were effective on endoscopic success rate and scar development. Based on these results, it could be thought that VUR time may be effective in selecting the best candidates for surgery and in the management and timing of treatment of VUR patients.

Veziko üreteral reflü hastalığında ultrasonun rolünü nasıl belirleyebiliriz?

Objectives: We aimed to explore the role and indication for the use of ultrasonography (US) in the vesico-ureteral reflux (VUR) disease and demonstrate the non – inferiority against the gold standard voiding cystourethrography (VCUG) for the screening in a certain group of patients. Material and Methods: This is a retrospective analysis of 532 simultaneous VCUG and US examinations between April 2010 and March 2019, by a single radiologist in our hospital. Demographic characteristics, pelvic stasis, pelvi – calyxeal dilatation and hydro – uretero – nephrosis in the US, and reflux in the VCUG were recorded. ROC analysis was done for comparing the two tests. Results: Among the cases between 5 months to 18 years of age, 342 (64.3 %) were female, and 190 (35.7 %) were male. The cases were divided into two groups below and after 6 years of age (N = 246 (46.2 %), and 286 (43.8%) respectively. There was a correlation between US and VCUG findings below the age of 6 (p<0.005, OR=6,977), but not in the cases over (p=0,539). In the ROC analysis of US in detection of VUR, compared to VCUG, sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) below 6 years age is 89,76 %, 47,86 %, 65,1 %, and 81,2 % (AUC= 0,688, p= 0,0001) respectively, and those above 6 years of age are 50,49 %, 53,55 %, 38,0 %, and 65,8 % (AUC=0,520, p= 0,5720). Conclusion: US is easy, reproducible, safe and effective for diagnosis, and staging of the disease. Its high sensitivity (89.7 %), and negative predictive value (81.2 %), can make it an initial screening test in the patients below 6 years of age. VCUG as a gold standard modality can be reserved for definitive diagnosis in the suspected cases below the age of 6 and all of the cases after the age of 6.

Effect of Reader and Patient Parameters on the Performance of Last-Image-Hold for Fluoroscopic Grading of Vesicoureteric Reflux.

OBJECTIVE. The purpose of this study is to determine the effect of different reader and patient parameters on the degree of agreement and the rate of misclassification of vesicoureteric reflux grading on last-image-hold frames in relation to spot-exposed frames from voiding cystourethrography (VCUG) as well as to determine the nature of reflux misclassification on last-image-hold frames. MATERIALS AND METHODS. Blinded readers conducted a retrospective evaluation of last-image-hold and spot-exposed frames of the renal fossae from 191 sequential VCUG examinations performed during a five-year period. Kappa tests were used to determine the agreement between reflux gradings and to assess the impact of reader and patient parameters. Pearson product-moment correlations were used to evaluate the effect of patient parameters on reader level of certainty regarding reflux grading. RESULTS. We measured almost perfect overall agreement for more experienced readers and substantial overall agreement for less experienced readers. Point estimates of overall misclassification were less than 2% for more experienced readers and less than 4% for less experienced readers. The readers' level of certainty about reflux grading had a positive impact on agreement values and misclassification rates. Experienced readers' most common misclassification was assigning reflux a grade of 3 on a spot-exposed frame and a grade of 2 on an equivalent last-image-hold frame. Inexperienced readers' most common misclassification involved missing reflux altogether. CONCLUSION. Instances of grade 2 reflux on last-image-hold frames may warrant supplemental evaluation with spot-exposed frames. Otherwise, a reader's level of certainty regarding reflux grading on a last-image-hold frame may help determine whether a supplemental spot-exposed frame would be beneficial.

Subsequent cancer risk of children receiving post voiding cystourethrography: A nationwide population-based retrospective cohort study

To estimate the subsequent cancer risk of children receiving post voiding cystourethrography (VCUG), a nationwide population-based retrospective cohort study with the data from the Taiwan National Health Insurance Research Database (NHIRD) were used for the analysis. In the VCUG cohort, 31,908 participants younger than 18 years of age who underwent VCUG between 1997 and 2008 were identified from the NHIRD. A comparison cohort, the non-VCUG cohort, was randomly selected among children without VCUG examination histories during 1997-2008, frequency matched for age (every 5 years), sex, geographic region area, parents' occupation, and index year based on a 1:4 ratio. Cox's proportional hazard regression analysis was conducted to estimate the subsequent cancer risk of children receiving VCUG. The overall cancer risk of the VCUG cohort is 1.92-fold (95 % CI = 1.34-2.74) higher than that of the non-VCUG cohort with statistical significance. The genital cancer and urinary system cancer risks of the VCUG cohort are respectively 6.19-fold (95 % CI = 1.37-28.0) and 5.8-fold (95 % CI = 1.54-21.9) higher than those of the non-VCUG cohort with statistical significance. The hazard ratios are higher in genital cancer, urinary system cancer (the major radiation exposure area), and cancer of the abdomen, except for the genitourinary system (the minor radiation exposure area), in sequence. Pediatric VCUG is associated with increased subsequent cancer risk, especially in the genitourinary system.

Voiding Cystourethrography Revisited: Descriptive Statistics for the Detection of Vesicoureteral Reflux

To determine which factors might influence the detection of vesicoureteral reflux (VUR), we retrospectively reviewed factors including fluoroscopy time, number of true radiographic acquisitions, and patient characteristics from a large number of voiding cystourethrography (VCUG) examinations. Nine hundred eighty-seven VCUG examinations performed between March 2006 and March 2009 were randomly selected for review. Data recorded were presence of VUR, patient age and sex, examination indication, follow-up status, presence of a diagnostic radiology trainee, fluoroscopy time, and number of true radiographic acquisitions. For initial examinations, descriptive comparison and logistic analyses were performed. To evaluate which variables related to reflux identification, we analyzed variables by logistic regression after stratifying by patient age (≤ 1 or > 1 year) for both the full sample and cases grouped by VUR severity (grades I and II [mild] or grades III-V [moderate to severe]). Nine hundred eighty-seven VCUG examinations were evaluated for the study (65.5% female; mean age, 3 years 2 months; age range, 2 weeks-16 years), and 761 cases met the inclusion criteria. VUR was detected in 101 of 349 infants (40 mild, 61 moderate to severe) and in 107 of 412 children older than 1 year (52 mild, 55 moderate to severe). A wide range of fluoroscopy times was similar between both positive and negative cases (0.033-4.233 minutes). The number of true radiographic acquisitions differed significantly between the negative and positive cases. Descriptive statistics and logistic regression analyses for a large number of VCUG examinations in a pediatric population are summarized. Our results showed that high fluoroscopy times were not associated with a higher likelihood of VUR. There may be a small benefit to the use of true radiographic acquisitions for detecting VUR.

Physician Documentation of Fluoroscopy Time in Voiding Cystourethrography Reports Correlates With Lower Fluoroscopy Times: A Surrogate Marker of Patient Radiation Exposure

Radiation awareness has been advocated as a method of decreasing radiation exposure. For fluoroscopy, one indicator of radiation use is fluoroscopy time. We retrospectively reviewed fluoroscopy times on voiding cystourethrography (VCUG) studies performed at a major pediatric center, comparing the average fluoroscopy time of examinations with the fluoroscopy time documented in the report to the average time of those without documentation. A database search of records for the period between June 1, 2002, and March 31, 2009, identified all VCUG examinations and their recorded fluoroscopy time in the radiology information system. Those examinations in which the fluoroscopy time was documented in the radiologist's report were also identified. Average fluoroscopy times were calculated for three groups: all VCUG examinations, examinations without the fluoroscopy time documented in the dictated report, and examinations including the fluoroscopy time in the dictated report. Over the 7-year study period, 10,594 VCUG examinations were performed. The average fluoroscopy time was 47 seconds for all examinations, 50 seconds for examinations without fluoroscopy time reported (n = 8484), and 32 seconds for examinations with fluoroscopy time reported (n = 1979). There was a statistically significant difference between examinations with and without fluoroscopy time reported by the radiologist (p < 0.0001). A decreasing trend in average fluoroscopy time for all VCUG examinations was identified over time (average fluoroscopy time: 65 seconds for 2002-2003 vs 29 seconds for 2008-2009). Radiologists also increasingly reported fluoroscopy time over time (fluoroscopy time reported in 1% of reports in 2002-2003 vs 82% in 2008-2009). Radiologist reporting of fluoroscopy time correlates with a decrease in fluoroscopy time, a surrogate indicator of radiation dose. Our findings suggest that the radiologist's documentation of fluoroscopy time in the report is part of a radiation awareness strategy leading to decreased fluoroscopy times.

Characteristics of First Urinary Tract Infection With Fever in Children

Our objective is to provide the clinical characteristics, uropathogen frequencies, and antimicrobial resistance rates of first urinary tract infection (UTI) diagnosed in febrile Belgian children. The ability of noninvasive ultrasound to detect renal abnormalities and vesicoureteral reflux (VUR) in these patients was also assessed. We prospectively followed (median, 20 months) 209 children treated for first febrile UTI. Renal ultrasound (US) and voiding cystourethrography examinations were performed in all patients. Among these children, 63% were females and 37% were males, and 75% of them had their first UTI before the age of 2 years. The most common causative agent was Escherichia coli (91% of cases) with high rate resistance to ampicillin (58%) and trimethoprim/sulfamethoxazole (38%). Of these children, 25% had evidence of VUR (15 boys and 38 girls). VUR was of low grade in 85% of cases. The overall performance of renal US as a diagnostic test to detect significant uropathies excluding low-grade VUR was excellent; the sensitivity attained 97% and the specificity 94%. Girls represent 63% of cases with first UTI. For 91% of UTIs, Escherichia coli is held responsible with a high rate of resistance to ampicillin and trimethoprim/sulfamethoxazole. US is an excellent screening tool that allows avoidance of unjustified voiding cystourethrography studies.

Febrile Urinary Tract Infections in 0- to 3-Month-Old Infants: A Prospective Follow-Up Study

To track the clinical evolution of febrile urinary tract infection (UTI) diagnosed in 0- to 3-month-old infants and characterize uropathogen frequencies, antimicrobial resistance rates, renal abnormalities, and differences in the sexes in this age group. We observed prospectively 46 infants identified in a cohort of 209 children with first UTI diagnosed between July 2006 and July 2008 at the age of 0 to 3 months. Renal ultrasound scanning and voiding cystourethrography examinations were performed in all infants. Infants < 3 months old represented 21% of all children with first UTI. Of these children, 26% were female and 74% were male. Escherichia coli was isolated in 88% of cases and had a high rate of resistance to ampicillin (71%) and to trimethoprim/sulfamethoxazole (47%); 21% of children had vesicoureteral reflux, which was of low-grade in 67% of cases, with spontaneous resolution before 2 years in all cases. In infants with normal ultrasound scanning results, a low-grade vesicoureteral reflux was subsequently found in 10% of cases. Infants aged 0 to 3 months represent 21% of children treated for febrile UTI. Boys represent 74% of these cases. E coli is responsible for 88% of UTIs, with a high rate of resistance to antibiotics. When ultrasound scanning examination results are normal, the risk of missing a significant renal abnormality is expected to be extremely low.

Urine sensor device for fluoroscopy time reduction in pediatric voiding cystourethrography

Purpose We evaluated the feasibility of a using urine sensor for voiding cystourethrography (VCUG) and its implications for fluoroscopy time reduction. Materials and methods Institutional Review Board approved the study protocol. Study population included children less than 5 years old referred to our institution for VCUG. Patients with known vesicoureteral reflux or any pacing device were excluded from the study. The urine sensor consists of an electrode that senses the fluid, an electrical circuit and an indicator to provide visual signal. The urine sensor electrode was placed on the medial thigh in the proximity of the catheter close to the urethral opening, but without direct contact to it. A standard VCUG examination was performed with retrograde filling of the urinary bladder. Once the bladder was full, fluoroscopy of the voiding stage was initiated when the indicator blinked. Peak kV and fluoroscopy time were recorded. Results Seven patients underwent VCUG with urine sensor and 22 patients without urine sensor. The urine sensor provided a reliable indication of voiding onset. The fluoroscopy time was significantly shorter with urine sensor use (1.99 min) than without urine sensor use (4.33 min) ( p = 0.001). In patients with normal VCUG, fluoroscopy time was also significantly shorter with urine sensor use (2.13 min) than without urine sensor use (4.39 min) ( p < 0.001). Conclusion VCUG studies with the help of the urine sensor are feasible and its use may result in significant reduction in fluoroscopy time.

Effective dose estimation for pediatric voiding cystourethrography using an anthropomorphic phantom set and metal oxide semiconductor field-effect transistor (MOSFET) technology

The risks associated with radiation exposure are higher in children than in adults. Therefore the use of fluoroscopy in common pediatric examinations such as voiding cystourethrography (VCUG) requires accurate determination of the associated effective dose. To estimate effective dose for VCUG examinations performed in children younger than 10 years using anthropomorphic phantoms and metal oxide semiconductor field-effect transistor (MOSFET) dosimeters. MOSFETs were placed within four phantoms representing children </=10 years old, at locations corresponding to radiosensitive organs, and exposed to a mock VCUG (5 min of fluoroscopy, 50 spot exposures) to minimize measurement error. Effective dose was measured and scaled to a standardized clinical VCUG (1 min fluoroscopy, 5 spot exposures) determined from patient logs. Monte Carlo simulations were performed to assess the accuracy of the measured effective dose. The dose area product (DAP) from each VCUG was compared to the effective dose. Effective doses ranged from 0.10 to 0.55 mSv, increased with age, and were higher in girls. Fluoroscopy accounted for 88-90% of the total effective dose, and spot exposures 10-12%. MOSFET-measured and simulation-derived effective doses were comparable (T > 0.12). DAP was strongly correlated with effective dose for both genders (r (2)>0.97, P < 0.0001). Effective doses for VCUG examinations performed in children <or=10 years of age are low but not negligible.

Conscious Sedation Reduces Distress in Children Undergoing Voiding Cystourethrography and Does Not Interfere with the Diagnosis of Vesicoureteric Reflux: A Randomized Controlled Study

Voiding cystourethrography (VCU) is a distressing procedure for children. Conscious sedation using oral midazolam may reduce this distress, but its use may also alter the ability of the VCU to show vesicoureteric reflux (VUR). The objectives of our study were to assess the effectiveness of conscious sedation using oral midazolam when administered routinely in children undergoing VCU and to ensure that conscious sedation using oral midazolam does not alter the ability of VCU to show VUR. Our study was a randomized double-blind controlled trial performed at a university teaching hospital; our study group consisted of children over the age of 1 year who been referred for their first VCU examination from July 2001 to July 2003. Participants were randomized to receive a placebo or midazolam syrup (0.5 mg/kg) before the examination. The primary outcome measures were the Groningen Distress Rating Scale (GDRS) and grading of VUR, as defined by the international grading system established by the International Reflux Study Group. There were no serious adverse events. One hundred thirty-nine children were randomized in the study, and 117 underwent complete assessment. Eight who underwent VCU after the study day were included in a "complete case" intention-to-treat analysis. In the placebo group, 34 children (61%) experienced serious distress or severe distress (GDRS score, 3 or 4). In the midazolam group, 16 children (26%) experienced the same degree of distress. There was a significant difference between the GDRS scores (nonlinear mixed-model analysis, p < 0.001) of the two study groups. The number needed to treat to reduce serious or severe distress in one child was 2.9 (95% CI, 1.9-5.5). VUR was identified in 16% of all children. There was no difference in VUR grading between the groups (nonlinear mixed-model analysis, p = 0.31). Routine use of oral midazolam (0.5 mg/kg) for conscious sedation of children undergoing VCU reduces distress and does not alter the ability of VCU to show VUR well enough to allow diagnosis.

Cyclic voiding cystouretrography without the use of fluoroscopic monitoring

Purpose To determine whether cyclic voiding cystourethrography (VCUG) examinations can be performed without using real-time fluoroscopic monitoring. Materials and methods VCUG examinations were performed in 209 children (133 girls and 76 boys). In each child, it was performed in a cyclic manner (three consecutive cycles) without using fluoroscopic monitoring and one radiograph was taken in each cycle of the examination. All patients were sedated by midazolam prior to examination. The degree of vesicoureteric reflux (VUR) was graded for each of the kidney ureter units (KUU) (total 418 KUU) separately. Statistical analysis included the comparison of the presence and absence of VUR and three ordinal-matched comparisons of each cycle. Results VCUG was detected in 37.3% of the children (78/209) and 28.7% (120/418) of the KUU. The absence of or same degree of VUR in three consecutive cycles were obtained in 345 KUU and the agreement was calculated as 82.5%. The same degree and presence of reflux were found in 85 and 89 refluxing KUU, the same negative findings (absence of VUR) in 306 and 298 KUU, and discordant findings in 27 and 31 KUU (between the first and second and between first and third cycles), respectively. Therefore, the agreement was 93.5 and 92.5% between the first and second cycles ( p = 0.70) and between the first and the third cycles ( p = 0.15), respectively. Conclusion Both the cyclic nature of this study and the results indicated that VCUG without real-time fluoroscopic monitoring could be used where adequate fluoroscopic examination is not possible for children in whom VUR detection is necessary and impacts treatment. However, the responsibility of pediatric radiologist always must also include the task to provide proper equipment for imaging children with suspected VUR.

Vesicoureteral Reflux Imaging in Children: Comparative Cost Analysis

Rationale and Objectives The purpose of this study was to compare the costs of voiding cystourethrography (VCUG) versus radionuclide cystography (RNC) for evaluation of vesicoureteral reflux in children. Materials and Methods The variable direct costs of performing 25 VCUG and 25 RNC examinations in age- and general health–matched patients suspected of having vesicoureteral reflux was determined by using time and motion analyses. All personnel directly involved in the cases were tracked, and the involvement times were recorded to the nearest minute. All material items used during the procedures were recorded. The cost of labor was determined from personnel reimbursement data, and the cost of materials, from vendor pricing. The fixed direct costs were assessed from hospital accounting records. Mean, standard deviation, and 95% confidence interval (CI) were determined for all direct (fixed and variable) costs. The total costs were determined for each procedure and compared by using the Student t test. Results There was a significant difference ( P < .0001) between the mean total direct cost of VCUG ($112.17 ± 10.33) and that of RNC ($64.58 ± 1.91). VCUG examination for vesicoureteral reflux in children cost 1.74 times more than RNC examination (95% CI: 1.28, 2.36). Conclusion When the technique is clinically appropriate, institutions may obtain substantial cost savings by using RNC in place of VCUG for examining children suspected of having vesicoureteral reflux.

Patterns of Integration and Clinical Value of Voiding Cystourethrography in the Work-Up of Urinary Tract Infection in Children

To evaluate the patterns of integration and the clinical value of voiding cystourethrography (VCUG) in the imaging work-up of children with urinary tract infection (UTI). We reviewed the medical records of a consecutive sample of 80 children that underwent VCUG as part of routine investigation for UTI. We assessed the following: the appropriateness of integration of VCUG in the patient work-up as determined by the presence or absence of a valid indication for VCUG in the specific clinical situation encountered, the correct timing of the examination and interpretation of its result; the change in clinical management initiated by the result of the test, and the reassurance conferred to the clinician. Sixty-nine percent of the VCUG examinations were judged appropriately integrated, 14% of the examinations inappropriately integrated, while for the rest of the patients (17%) the appropriateness of integration of the test was rated as unclear. The change in patient management attributable to the VCUG result could be categorized as: no change (15%); decision to end the imaging investigation of the patient (39%); decision to end all investigations, and prophylactic or therapeutic interventions (17%); decision to discontinue chemoprophylaxis (1%); decision to end the imaging investigation and introduce chemoprophylaxis and follow-up for bacteriuria (5%); decision to continue the imaging investigation and introduce chemoprophylaxis and follow-up for bacteriuria (15%), and decision to operate or help in planning the surgical treatment required (8%). The findings show the need for an increased effort to minimize overuse of VCUG in pediatric UTI. Future interventions should focus on issues of clinical efficacy of the method that may have not been emphasized sufficiently.

Enhanced detection of vesicoureteral reflux in infants and children with use of cyclic voiding cystourethrography.

Cyclic voiding cystourethrography (VCUG) was prospectively evaluated to determine its ability to demonstrate vesicoureteral reflux (VUR) in children whose VCUG results were initially negative. The authors also assessed the effect of change in the patient's position on the detection of VUR. Seventy-seven children younger than 3 years of age, with negative results from a VCUG study performed while they were supine, underwent a second cycle of bladder filling after they were placed prone (group 1). Sixty-five children who were also younger than 3 years of age and had negative results from an initial VCUG examination performed in the usual supine position underwent a second cycle of bladder filling, which was also performed with the patient supine (group 2). VUR occurred in three children (4%) in group 1 and in eight (12%) in group 2. Most children (68.8%) in the two groups combined had grade II reflux. Cyclic VCUG increased detection of VUR, which led to a change in clinical treatment. Prone positioning did not enhance detection of VUR to the same degree as did multiple studies performed with the patient supine.