Cystoscopic and DMSA findings in relation to types of reflux demonstrated on percutaneous direct radionuclide cystography in children

Background The new technique of percutaneous direct radionuclide cystography (PDRC) allows the accurate demonstration of vesicorenal reflux under physiological conditions during resting and micturition phases. Five types of reflux have been described, the clinical relevance of which is uncertain.Objective To determine whether a relationship exists between the type of reflux identified on PDRC and the appearance of the ureteric orifice at cystoscopy or the prevalence of renal abnormalities.Materials and methods The reports of 281 PDRC examinations were reviewed and 76 children with reflux formed the population of this study. Studies of these children were reviewed to classify the reflux as types 1–5, and patient records were searched for cystoscopy and DMSA scan reports.Results Regardless of the type of reflux, the ureteric orifices were found to be open at cystoscopy in 60–66% of refluxing units. DMSA scan abnormalities were present in 68% of units with reflux at rest, 61% of units with reflux on micturition and 86% of units with reflux on both resting and micturition phases. In comparison with contralateral units that did not reflux, the presence of reflux had a significant association with openness of the ureteric orifice (p<0.00001) and DMSA abnormality (p<0.005).Conclusions Reflux of any type is strongly associated with an open ureteric orifice. Units that reflux during both resting and micturition phases had a higher incidence of DMSA abnormality than those refluxing during one phase only, but this was not statistically significant.     

“Stasis” — A test for vesico-ureteric orifice competence in children with reflux

Intravenous radionuclide cystography (IVRNC) with one injection of 99m-Tc-DTPA measures renal function and detects vesico-renal reflux [1, 2,3]. This paper describes a possible means of detecting incompetent ureteric orifices during IVRNC examinations. In some patients a hold-up of material in the renal areas (stasis) was observed which suddenly cleared at micturition. A prospective study of 58 patients who had IVRNC and cystoscopy within 28 days of each other revealed that 76.3% had anatomically abnormal ureteric orifices on the same side as the stasis. This contrasted with only 12.8% of abnormal ureteric orfices found in patients not showing stasis (p<0.005). As incompetent ureteric orifices are recognised as the major aetiological factor in vesico-renal reflux [4, 5, 6] this additional information gained at IVRNC could be of clinical use and perhaps avoid some cystoscopies.     

The importance of follow-up of children with vesicoureteral reflux grade 1

AIM: The objectives of this study were, first, to determine the probability of detecting vesicoureteral reflux (VUR) into the renal collecting system (VUR grade 2 or higher) by follow-up cyclic radionuclide cystography (CRC) in children with VUR 1 on initial examination, and in children without VUR and with the same clinical history; and secondly, to find out whether dividing VUR 1 into three subclasses, including possible reflux into the ureter, reflux into the lower ureter, and reflux into the whole length of the ureter, enhances detection of higher grade reflux in these children. METHODS: 275 children with VUR 1 found on initial CRC, and 31 children without reflux and with the same clinical history were studied. In total, 414 renal units with VUR 1 of different subclasses and 198 renal units without reflux were evaluated. RESULTS: Follow-up CRC disclosed reflux into the renal collecting system in 20% of children with VUR 1 on initial investigation, and in 23% of children with no reflux at the time of initial investigation. The probability that follow-up examination would disclose VUR 2 in 3 in renal units with different subclasses of grade 1 reflux was 8-16%, and did not differ significantly from the probability for detecting reflux in kidneys with no reflux on initial examination. CONCLUSION: In the absence of recurrent urinary tract infection, the management of children with VUR 1 identified by CRC can be the same as in children without reflux. Yet, in children with no reflux or with VUR 1 detected after urinary tract infection, the probability that reflux reaching the pylon was missed should not be underestimated. Dividing VUR 1 into subclasses does not seem to be of diagnostic value.     

A prospective study of children with first acute symptomatic E. coli urinary tract infection. Early 99mtechnetium dimercaptosuccinic acid scan appearances

Between 1985 and 1987 102 children, age 0-14 years, presented with a first acute symptomatic E. coli urinary tract infection. Investigations included early 99mtechnetium dimercaptosuccinic acid (DMSA) scan (which was performed at a median of 27 days), ultrasonography, micturating cysto-urethrography and indirect voiding radionuclide cystography using 99mTc DTPA. Follow-up DMSA scan was carried out after 6 months. Twenty-one of 102 of initial DMSA studies showed diminished uptake of radionuclide and 12 showed cortical scarring. Twenty-nine patients had significant vesicoureteral reflux (VUR). The finding of diminished uptake on the initial scan was significantly associated with fever, systemic upset, length of symptoms and a peripheral blood leucocytosis, (p less than 0.05). In addition the finding was associated with fever and loin pain in the older child. Both diminished uptake and scarring were more common in refluxing kidney units. We propose that, in children with UTI, diminished uptake on early DMSA scan localises infection in the renal parenchyma.     

A Prospective Study of Children with First Acute Symptomatic E. coliUrinary Tract Infection Early 99mTechnetium Dimercaptosuccinic Acid Scan Appearances

ABSTRACT. Between 1985 and 1987102 children, age 0–14 years, presented with a first acute symptomatic E. coli urinary tract infection. Investigations included early ^99mtechnetium dimercaptosuccinic acid (DMSA) scan (which was performed at a median of 27 days), ultrasonography, micturating cysto-urethrography and indirect voiding radionuclide cystography using ^99mTc DTPA. Follow-up DMSA scan was carried out after 6 months. Twenty-one of 102 of initial DMSA studies showed diminished uptake of radionuclide and 12 showed cortical scarring. Twenty-nine patients had significant vesicoureteral reflux (VUR). The finding of diminished uptake on the initial scan was significantly associated with fever, systemic upset, length of symptoms and a peripheral blood leucocytosis, (p<0.05). In addition the finding was associated with fever and loin pain in the older child. Both diminished uptake and scarring were more common in refluxing kidney units. We propose that, in children with UTI, diminished uptake on early DMSA scan localises infection in the renal parenchyma.     

Cystosonography with echocontrast: a new imaging modality to detect vesicoureteric reflux in children

Background. Conventionally, vesicoureteric reflux (VUR) is assessed by fluoroscopic micturating cystourethrography (MCU) or direct or indirect radionuclide cystography (RNC). There is preliminary experience with contrast-enhanced sonography for the detection of VUR. Objective. To evaluate the usefulness of contrast-enhanced ultrasonography using galactose suspension as an echogenic contrast medium. Materials and methods. In this study a galactose suspension was instilled into the bladder in 58 neonates, infants and children along with normal saline to detect the presence and the severity of VUR through the enhanced US signal. The results were compared with those of MCU and RNC. One ml/kg of echocontrast in the neonatal age group, and 0.5 ml/kg thereafter, were slowly instilled through a 4-F catheter after preliminary supine and prone urinary tract US. Indications for the investigation were antenatally diagnosed pyelectasis (21 cases) and pyelonephritis (37 cases). In 38 patients echocontrast cystosonography (ECS) was performed before, and in 20 patients after, MCU or RNC. Results. ECS detected 76 refluxing units in 50 patients. In eight patients, no VUR was shown, and none of these developed a urinary tract infection in 18 months of follow-up. In 43 patients, MCU or RNC detected 62 refluxing units, while in 15 no VUR was shown. Taking MCU as the gold standard and using the same grading scale, the sensitivity of ECS was 100 %. No side effects were observed. Several urinary tract abnormalities were detected by ECS. The male urethra was studied by ECS, both by retrograde infusion and during micturition. Conclusions. ECS is a promising imaging technique for detecting and grading VUR without exposing patients to ionising radiation. Received: 29 September 1997 Accepted: 14 November 1997     

Vesicoureteral reflux in asymptomatic siblings of patients with known reflux: radionuclide cystography

The familial nature of vesicoureteral reflux among siblings of patients with vesicoureteral reflux has been reported to be from 8% to 32%. These included both symptomatic and asymptomatic siblings. The incidence of vesicoureteral reflux in asymptomatic siblings, however, has not been studied extensively. Sixty asymptomatic siblings of patients known to have vesicoureteral reflux were studied with radionuclide voiding cystography. Their ages ranged from 2 months to 15 years (mean, 4.2 years). Vesicoureteral reflux was detected in 27 of 60 (45%) of the siblings. Vesicoureteral reflux was unilateral in 15 and bilateral in 12 of the siblings. Radionuclide cystography is more sensitive than radiographic cystography and results in a very low radiation dose to the patient. The gonadal dose with radionuclide cystography is only 1.0 to 2.0 mrads. Because of these features, radionuclide cystography is a nearly ideal technique for the diagnosis of vesicoureteral reflux in siblings of patients with known vesicoureteral reflux. All siblings (symptomatic or asymptomatic) of patients with known vesicoureteral reflux should have a screening radionuclide cystography.     

The presence of vesicoureteric reflux does not identify a population at risk for renal scarring following a first urinary tract infection

Background: Childhood urinary tract infection (UTI) with or without vesicoureteric reflux (VUR) may predispose to renal scarring. There is no clear consensus in the literature regarding imaging following UTI in infancy. Aims: To define the role of cystography following a first UTI in children aged under 1 year, when urinary tract ultrasonography (US) is normal. Methods: Retrospective data collection of 108 children (216 renal units) aged under 1 year at the time of a bacteriologically proven UTI. All had a normal US and underwent both catheter cystogram and DMSA test. Sensitivity, specificity, likelihood ratios positive and negative, and diagnostic odds ratio were calculated for VUR on cystography versus scarring on DMSA. Results: VUR was shown in 25 (11.6%) renal units. Scarring on DMSA was seen in 8 (3.7 %) kidneys. Only 16% of kidneys with VUR had associated scarring; 50% of scarred kidneys were not associated with VUR. The likelihood ratio positive was 4.95 (95% CI 2.22 to 11.05) and the likelihood ratio negative was 0.56 (95% CI 0.28 to 1.11). The diagnostic odds ratio was 8.9, suggesting that cystography provided little additional information. Conclusion: Since only 16% of children with VUR had an abnormal kidney, the presence of VUR does not identify a susceptible population with an abnormal kidney on DMSA. In the context of a normal ultrasound examination, cystography contributes little to the management of children under the age of 1 year with a UTI. In this context, a normal DMSA study reinforces the redundancy of cystography.     

The presence of vesicoureteric reflux does not identify a population at risk for renal scarring following a first urinary tract infection.

BACKGROUND: Childhood urinary tract infection (UTI) with or without vesicoureteric reflux (VUR) may predispose to renal scarring. There is no clear consensus in the literature regarding imaging following UTI in infancy. AIMS: To define the role of cystography following a first UTI in children aged under 1 year, when urinary tract ultrasonography (US) is normal. METHODS: Retrospective data collection of 108 children (216 renal units) aged under 1 year at the time of a bacteriologically proven UTI. All had a normal US and underwent both catheter cystogram and DMSA test. Sensitivity, specificity, likelihood ratios positive and negative, and diagnostic odds ratio were calculated for VUR on cystography versus scarring on DMSA. RESULTS: VUR was shown in 25 (11.6%) renal units. Scarring on DMSA was seen in 8 (3.7 %) kidneys. Only 16% of kidneys with VUR had associated scarring; 50% of scarred kidneys were not associated with VUR. The likelihood ratio positive was 4.95 (95% CI 2.22 to 11.05) and the likelihood ratio negative was 0.56 (95% CI 0.28 to 1.11). The diagnostic odds ratio was 8.9, suggesting that cystography provided little additional information. CONCLUSION: Since only 16% of children with VUR had an abnormal kidney, the presence of VUR does not identify a susceptible population with an abnormal kidney on DMSA. In the context of a normal ultrasound examination, cystography contributes little to the management of children under the age of 1 year with a UTI. In this context, a normal DMSA study reinforces the redundancy of cystography.     

Intraoperative cystography pre- and post-endoscopic treatment for vesicoureteral reflux: Guaranteed success?

ObjectiveThis study was designed to investigate whether post-endoscopic treatment (ET) intraoperative cystography is predictive of treatment outcome.Patients and methodsPatients diagnosed with vesicoureteral reflux (VUR) and treated endoscopically with polyacrylate/polyalcohol copolymer or dextranomer hyaluronic acid were studied prospectively between August 2009 and April 2011. Slow infusion pre-ET cystography was performed under anesthesia. Post-ET cystography was performed only if the intraoperative pre-ET results demonstrated VUR.ResultsOver a period of 20 months, 23 patients were studied (18 girls, five boys), with an average age of 41.9 months (range 13 months–11 years). Thirty-two renal units with reflux were treated: nine bilateral cases, seven right, and seven left. The distribution of reflux grades was as follows: two grade I, 10 grade II, 11 grade III, nine grade IV. All injected ureters demonstrated grade 0 hydrodistention after the procedure. Twelve of 23 of the pre-ET cystography results were negative for VUR, indicating that the sensitivity of this test is 47% compared with the preoperative voiding cystourethrography (VCUG) or nuclear cystogram. There were no procedure complications.ConclusionOf all patients (n = 23), nearly 60% did not demonstrate pre-ET VUR on intraoperative cystography. If a postoperative VCUG had been performed on all patients, more than half would have received unnecessary radiation. Therefore, this study demonstrates that post-ET cystography does not predict the success of ET of VUR intraoperative. Pre-ET cystography under general anesthesia before ureteral injection, has very low sensitivity, creating false-negatives that may complicate the interpretation of post-ET cystography. We suggest that intraoperative cystography before and after ET fails to show clinical utility and should not be used to predict the outcome of endoscopic VUR treatment.     

Urinary bladder volume and pressure at reflux as prognostic factors of vesicoureteral reflux outcome

Background: Controversy exists as to whether the outcome of vesicoureteral reflux (VUR) can be prognosticated by direct radionuclide cystography (DRC).Objective:To correlate the quantitative data obtained by DRC with disease outcome in infants with VUR and positive DRC 1 year after diagnosis. Materials and methods: The medical records of 109 children with known primary VUR diagnosed during the first year of life were studied retrospectively. One year after diagnosis all patients underwent DRC. Children with a positive first DRC were followed up for the next 36 months. Fishers exact test was used to calculate the statistical significance of differences in the number of ureters with resolved reflux, as related to quantitative data obtained during the first DRC. Results:The first DRC, performed 1 year after the initial diagnosis, was positive in 49 children (26 with bilateral reflux). Quantitative data derived from this first examination could not establish any prognostic value for a refluxing volume of <2% of the total vesical volume or a reflux at a bladder volume of more than 60% of total bladder capacity. When this limit was lowered to 45%, a statistically significant difference was found (P=0.046). Moreover, when a bladder pressure at the time of reflux of more than 20 cm H₂O was set as a criterion, an extremely significant probability value was calculated (P=0.0009). Conclusions: VUR occurring at a bladder pressure of less than 20 cm H₂O and a filling volume of less than 45% of the total bladder volume indicate a low probability for VUR resolution within the subsequent 36 months, in infants with known reflux.     

Cyclic direct radionuclide voiding cystography: Increasing reliability in detecting vesicoureteral reflux in children

The purpose of this study was to establish the sensitivity of cyclic direct radionuclide cystography (RVC) in detecting vesicoureteral reflux (VUR) in infants and small children, and to compare it to the conventional (one cycle only) RVC. 428 patients (856 renal units) were admitted to the study from January 1991 through March 1992 and all had a cyclic RVC. The age of the patients ranged from 4 months to 7 years. The overall agreement of both cycles in detecting VUR in this study was 45%, the lowest being in detecting VUR I (36%), and the highest in detecting VUR III (86%). If we had used a conventional RVC (the first cycle only), 17 (29%) VUR I, 50 (36%) VUR II and 3 (9%) VUR III, which were detected in the second cycle only, would have been missed. We conclude that cyclic RVC detected 43% more VURs than the conventional (first cycle only) RVC, and would therefore recommend its use as a standard procedure instead of the conventional RVC.     

Urinary tract infection in childhood. Review of guidelines and recommendations

Children with urinary tract infection continue to be an important part of the pediatric practice. New uroradiologic imaging techniques like cortical radionuclide scanning and prenatal ultrasonography improved our understanding of the etiology, effect of treatment and outcome of these patients. Evidently, most kidneys at risk are those which already sustained intrauterine damage by obstruction or vesicoureteral reflux. It is the pediatrician's role to minimize ex-utero damage caused by bacterial infection by early diagnosis and appropriate intervention. The introduction of new potent oral antimicrobials limits the need for hospitalization only to the very young infant and the very seriously ill child. Whereas the roles of routine renal ultrasound and cortical radionuclide scan are debatable, all young children and select older children have to be investigated by cystography for possible vesicoureteral reflux. In children with vesicoureteral reflux, long-term antibiotic prophylaxis is required in most children but in a few surgical correction might be indicated. Young siblings of the propositus with vesicoureteral reflux have to be investigated as well for possible reflux. This review covers these and other guidelines and recommendations of diagnosis and treatment of UTI in children at the beginning of the third millennium.     

Primary vesicoureteral reflux in infants with a dilated fetal urinary tract

Vesicoureteral reflux (VUR) was recognized neonatally by voiding cystography in 25 of 117 infants with a dilated fetal urinary tract. There was a male preponderance (76%) and a high percentage (40%) of associated urinary malformations. Thirtynine refluxing units were studied. All grades of VUR were detected but gross dilating VUR dominated (59%). Spontaneous resolution was excellent in lower grades of VUR but was poor in gross VUR. Surgery was successfully performed in 13 renal units of nine patients with gross reflux [8], additional ipsilateral malformations [4], or pyelonephritis during antibiotic prophylaxis [1]. Segmental renal scars developed in four kidneys after urinary infections, and a diffuse parenchymal lesion was noted in nine kidneys even at birth. One boy with duplication had a non-functioning refluxing system. Our results in a small number of infants show differences to children with VUR detected after urinary infections and seem to support the existence of a congenital reflux nephropathy.     

Urinary bladder rupture during voiding cystourethrography

Voiding cystourethrography (VCUG) is a commonly performed diagnostic procedure for the evaluation of vesicoureteral reflux with urinary tract infection or congenital renal diseases in children. The procedure is relatively simple and cost-effective, and complications are very rare. The iatrogenic complication of VCUG range from discomfort, urinary tract infection to bacteremia, as well as bladder rupture. Bladder rupture is a rare complication of VCUG, and only a few cases were reported. Bladder rupture among healthy children during VCUG is an especially uncommon event. Bladder rupture associated with VCUG is usually more common in chronically unused bladders like chronic renal failure. Presented is a case of bladder rupture that occurred during a VCUG in a healthy 9-month-old infant, due to instilled action of dye by high pressure. This injury completely healed after 7 days of operation, and it was confirmed with a postoperative cystography. The patient's bladder volume, underlying disease, velocity of the contrast media instilled, catheter size, and styles of instillation are important factors to prevent bladder rupture during VCUG. Management of bladder rupture should be individualized, but the majority of infants are treated with the operation. In conclusion, bladder rupture is a rare complication, however, delicate attention is needed in order to prevent more dire situations.     

Radionuclide imaging for vesico-renal reflux using intravenous 99mTc-D. T. P. A.

This study shows that Radionuclide imaging provides a simple method for detecting vesico-renal reflux in children, when an intravenous dose of 99^mTc-D. T. P. A. is used as radioactive tracer. Forty-eight patients have been studied, of these twenty-eight also had intravenous pyelography with post-micturition films, micturating cystography, and cystoscopy. In this group of 28 patients the radionuclide imaging technique detected 25 refluxing ureters and 9 cases of bilateral vesico-renal reflux. Micturating cystography detected 12 refluxing ureters and only 3 cases were bilateral. Cystoscopy revealed 20 abnormal ureteric orifices and 6 patients had bilaterally abnormal orifices. Radionuclide imaging agreed with both the micturating cystograms and cystoscopic findings that reflux was occuring in 6 ureters. Radionuclide imaging agreed with the impression at cystoscopy that reflux was present in 18 ureters. Only 6 of the ureters diagnosed by micturating cystography as having reflux had abnormal ureteric openings at cystoscopy. The intravenous radionuclide imaging technique avoids the unpleasantness of catheterisation and its attendant risk of introducing infection. A lower dose of radiation is received than during radiological techniques. A renogram is obtained as part of the test. We believe this intravenous radionuclide imaging technique is a more physiologically correct test for vesico-renal reflux than any of the methods using catheterisation. Its limitations are that it is not so easy to use in hyperactive toddlers, nor does it give the anatomical definition that radiological techniques provide although improvements are expected with the latest gamma cameras and their associated equipment.     

The asphyxiated bladder demonstrated by99mTc-D.T.P.A. renal scan

Radionuclide renal scanning is a useful aid in the assessment of the anuric or oliguric neonate. Whilst delayed micturition may be a normal physiological variation, it may be associated with a number of pathological states affecting any part of the urinary system. Four cases of the asphyxiated bladder phenomenon have been examined by^99mTc-D.T.P.A scan, showing slow renal excretion and gross bladder distension. This recently described condition should be borne in mind during the radionuclide examination of the newborn for urinary tract anomaly.     

Ultrasonography for the detection of ureteric reflux in infants with urinary infection

Several less harmful methods than voiding cysto-urethrography for detecting significant ureteric reflux have been proposed. The present prospective study investigated whether ultrasonography was effective in identifying ureteric reflux in infants with their first febrile urinary infection. The subjects were 27 infants (24 boys and 3 girls) aged from 0 to 8 months. The urinary tract was scanned when the bladder was full, and before and during induced voiding. Infants with abnormal ultrasound findings underwent voiding cysto-urethrography. The other infants were followed and those who had a recurrence of urinary infection underwent voiding cystography. Ten children underwent cysto-urethrography, with eight refluxing ureters identified in six boys. Ultrasound revealed transient dilatation of the renal pelvis on voiding in five kidneys, transient dilatation of distal ureters in 12 and hydro-ureteronephrosis in two. Each of the five kidneys with pelvic dilatation on voiding was associated with ureteric reflux grades III or IV. Of the 17 children who did not undergo cysto-urethrography, only one had recurrence of urinary infection and was diagnosed with ureteric reflux. This girl was one of the three babies who were not scanned during voiding. More than half of the infants with febrile urinary infection were excluded from invasive examination without having recurrence of urinary infection. Thus, ultrasound scanning during voiding was effective for screening infants with their first urinary infection to detect significant ureteric reflux.     

Is the mode of occurrence of vesicoureteral reflux correlated to bladder function and spontaneous resolution?

PurposeTo investigate whether mode of occurrence of vesicoureteral reflux (VUR), during micturition (M), during filling without increase in pressure (passive, P) or in response to an overactive contraction (OA), can be explained by differences in bladder function. Also, to study if the mode of occurrence of VUR can predict spontaneous resolution.Materials and methodsThere were 93 infants (68 boys and 25 girls) with VUR (grade III–V) included. Videocystometry was performed at median ages 5, 22 and 32 months registering grade and mode of reflux and bladder function characteristics.ResultsMode of occurrence of reflux changed with age. During infancy P, OA and M reflux comprised almost equal parts. At follow up, P reflux had increased and both OA and M reflux had decreased. This was partly due to a significantly higher probability of spontaneous resolution for M than P reflux, at 40 months (42 vs 18%). P and M reflux were significantly correlated to bladder function characteristics. P reflux was seen in children with high bladder capacity and occurred early in filling. Other predictors were higher age within the respective group and female sex. M reflux was correlated to lack of residual urine, low bladder capacity and absence of overactivity. Other indicators were male sex and low-grade reflux.ConclusionsP and M reflux correlate to different bladder patterns: P with high bladder capacity and M with low bladder capacity and without signs of bladder dysfunction. M seems to be benign with a higher resolution rate.     

Detection of low-grade vesicoureteral reflux in children by color Doppler imaging mode

Vesicoureteral reflux (VUR) is common in children with urinary tract infections (UTI) and may result in renal scarring or reflux nephropathy. To date, the primary diagnostic tool has been voiding cystourethrography (VCUG). A new technique for evaluation of grade 1 and 2 VUR is described using color Doppler imaging-mode cystography (CDIMC): 77 children, aged 7 months to 14 years, were examined for VUR by CDIMC and standard VCUG. According to the established reflux sonography (US) using a real-time mode, all patients selected for this study had a normal urinary tract on conventional gray-scale US. We studied 154 ureters, and a total of 31 were found to be refluxing on CDIMC and 30 on VCUG. A positive sonogram was defined as visualization of Doppler signals from the bladder to the ureter during the course of bladder filling. Taking VCUG as the gold standard, we had ten false-positive findings. The false-positive rate of 18.5% may have been due to the shorter observation time of fluoroscopy. Comparison of the two methods shows CDIMC to be 70% sensitive with a specificity of 92% in the detection of VUR grade 1 and 2. To evaluate the incidence of asymptomatic low-grade VUR in a non-infected population, a second series of 38 children (19 males, 19 females) aged 3 to 15 years (mean 8.8 years) with normal urologic status and urine cultures were studied by color Doppler imaging mode (CDIM) for detection of asymptomatic low-grade VUR. Four children were found to have a unilateral refluxing ureter. The incidence of VUR in children with a normal urinary tract and no prior UTI was 10.5%. In conclusion, CDIMC can be used as a possible alternative to standard VCUG for the screening and follow-up of low-grade VUR. In addition, our study indicates that asymptomatic grade 1 and 2 reflux might be a physiological condition.