***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Purpose : The aim of this study is to compare the results of direct radionuclide cystography ( DRNC ) and voiding cystourethrography ( VCUG ) in a group of children with a high suspicion of vesicoureteral reflux ( VUR ) . Methods : For this purpose , 25 children were studied with both VCUG and DRNC .  Among 50 ureter units able to be compared 39 ureter units did not show any VUR on either study . Eleven ureter units ( 10 children ) had VUR either on one study or on both ( VCUG and DRNC ) . In the children who had VUR on either study , a dimercaptosuccinic acid scintigraphy ( DMSA ) was performed to determine their cortical function . Results : We identified the following four patterns : 1 ) Five ureter units ( five children ) read positive on  DRNC  who were negative on VCUG and four of these children had positive findings on DMSA ; 2 ) Four ureter units ( four children ) read positive on VCUG who were negative on DRNC , and two of them had positive findings on DMSA ; 3 ) Two ureters ( one child ) read positive in both studies and also had abnormal DMSA findings ; 4 ) Thirtynine ureter units read as negative on both studies . Conclusion : Although the results of these two methods did not show a significant difference , DRNC offers a high sensitivity in the younger age group whereas VCUG seems to be more sensitive in the older age group . DRNC also offers continuous recording during the study , ease of assessment and lower radiation dose to the gonads , which makes it a preferable method for the initial diagnosis and follow-up of VUR PURPOSE When the st and ard cystogram does not show vesicoureteral reflux in children who have experienced febrile urinary tract infections ( UTIs ) , clinical management is controversial . We postulated that vesicoureteral reflux accounts for such UTIs but is " occult . " We tested this hypothesis by using a novel method , PIC cystography ( Positioning the Instillation of Contrast at the ureteral orifice ) at the time of cystoscopy . MATERIAL S AND METHODS We performed PIC cystography with instillation of contrast medium at the ureteral orifice consecutively and prospect ively in 57 children who underwent cystoscopy between November 1999 and February 2002 to evaluate febrile UTIs in 40 patients , dysfunctional voiding in 14 and hydronephrosis in 3 . The control group ( 27 patients , 54 renal units ) was used to assess the accuracy of PIC by comparing the results against those with the st and ard cystogram in children who did not have febrile infection and did not demonstrate vesicoureteral reflux ( 15 patients , 30 renal units ) , and in those who had febrile infection and vesicoureteral reflux ( 12 patients , 24 renal units ) . The study group ( 30 patients , 60 renal units ) served to assess the incidence of " occult " vesicoureteral reflux in children who experienced febrile UTIs yet did not have vesicoureteral reflux on st and ard cystography . RESULTS CONTROL GROUP In children without febrile UTIs all 30 ureteral orifices had a normal endoscopic appearance and no vesicoureteral reflux by PIC cystography . In children with febrile UTIs 15 ureteral orifices with known vesicoureteral reflux were lateral and /or patulous and demonstrated vesicoureteral reflux by PIC , 4 appeared normal and did not exhibit vesicoureteral reflux on st and ard cystography or by PIC , and 5 were lateral and /or patulous in appearance and did not display vesicoureteral reflux on st and ard cystography , but did show vesicoureteral reflux by PIC . These findings reveal that PIC cystography is 100 % sensitive at demonstrating reflux already known by st and ard cystogram , is 87 % specific as it showed reflux in 5 of 39 renal units not revealed by a st and ard cystogram and has an overall accuracy of 91 % . STUDY GROUP At cystoscopy all 30 children demonstrated an abnormal appearance of one or both ureteral orifices .  PIC cystography showed vesicoureteral reflux in all 30 children ( 48 renal units , 12 unilateral and 18 bilateral ) . The remaining ureteral orifices ( 12 ) , which appeared normal , did not permit vesicoureteral reflux . Children with vesicoureteral reflux by PIC were treated with antimicrobial prophylaxis ( 26 ) or ureteral reimplantation ( 4 , 2 unilateral and 2 bilateral reimplantation ) Postoperatively , these children did not experience a febrile UTI during followup ( average 8 months ) . CONCLUSIONS PIC cystography is simple to perform using routinely available operating room equipment and does not artifactually induce vesicoureteral reflux . The incidence of " occult " vesicoureteral reflux in children who experience febrile UTIs without vesicoureteral reflux on st and ard cystography is 100 % by PIC cystography . PIC cystography should be done when vesicoureteral reflux is suspected in children who experience febrile UTIs but do not exhibit reflux on st and ard cystography BACKGROUND Fluoroscopic voiding cystourethrography ( VCUG ) is a widely used imaging test for the diagnosis of vesicoureteral reflux ( VUR ) . However , high gonadal radiation and intermittent imaging are the main disadvantages of VCUG . Direct radionuclide cystography ( DRC ) has been advocated for the detection of VUR with increased sensitivity and low radiation doses , however , having the disadvantage of providing less anatomical details for urethral evaluation . In this study , DRC has been compared with st and ard fluoroscopic VCUG for detection of VUR . METHODS A total of 41 children ( 82 kidney ureter units , KUU ) aged 1 month-126 months ( median , 15 months ) were studied sequentially using DRC and VCUG . The indications of VUR studied were urinary tract infection in 29 children , VUR follow up in eight children and antenatal dilatation history in four children . RESULTS A total of 18 refluxing ureters were detected by DRC , 22 refluxing ureters by VCUG and 14 refluxing ureters by both methods . The two methods were concordant for the detection and exclusion of VUR in 85 % of KUU . VUR was missed by VCUG in four KUU ( three severe , one mild ) whereas VUR was missed by DRC in eight KUU ( four grade I , four grade III ) . CONCLUSIONS There was a good correlation between DRC and VCUG in the evaluation of VUR .  DRC provides continuous monitoring and low gonadal radiation exposure . DRC can be used in the diagnosis of VUR as an alternative to VCUG in selected cases PURPOSE Evaluation in children after febrile urinary tract infection involves voiding cystourethrogram , which emphasizes urinary reflux rather than renal risk . We believe that early dimercapto-succinic acid renal scan after febrile urinary tract infection predicts clinical ly significant reflux and which children should undergo voiding cystourethrogram . The criticism of this approach is that some reflux and preventable renal damage would be missed . This study vali date s the use of initial dimercapto-succinic scan and presents 5-year renal outcomes . MATERIAL S AND METHODS We prospect ively studied children with febrile urinary tract infection using initial dimercapto-succinic acid renal scan , voiding cystourethrogram and renal/bladder ultrasound . Children with anatomical or neurological genitourinary abnormality and protocol failures were excluded from analysis .  Dimercapto-succinic acid scan was repeated at 6 months if initially abnormal . Followup was done every 6 months in all children for at least 5 years . RESULTS A total of 121 children fit study inclusion criteria and completed the 5-year study . Overall 88 initial dimercapto-succinic acid scans ( 73 % ) were abnormal and 78 children ( 64 % ) had urinary reflux . The OR of having clinical ly significant reflux predicted by abnormal initial scan was 35.4 . Abnormal followup scan did not predict clinical ly significant reflux . Overall subsequent urinary tract infection developed in 32 patients ( 26.5 % ) and 27 ( 85 % ) had an abnormal initial scan . No child with a normal initial scan had clinical ly significant reflux . CONCLUSIONS Dimercapto-succinic acid scan can predict clinical ly significant reflux and children at greatest renal risk . Initial dimercapto-succinic acid scan should be done in all children after febrile urinary tract infection while voiding cystourethrogram should be reserved for those with an abnormal initial dimercapto-succinic acid scan Background Vesicoureteric reflux ( VUR ) and its complications are common problems encountered in paediatric practice . Voiding cystourethrography ( VCU ) is the primary investigation of choice . Direct radionuclide cystography ( DRC ) is utilized in the follow-up evaluation of children diagnosed with VUR . However , VCU and DRC both require catheterization , which children do not tolerate well . Objective In this prospect i ve study we evaluated radionuclide cystography by direct supra-pubic puncture ( SDRC ) and instillation of the radiotracer into the bladder , avoiding catheterization . The results of this procedure were then compared with those of VCU . Patients and methods A total of 43 children ( eight females and 35 males ; mean age , 5.73±3.28 years ; range , 1.5–12 years ) were studied . Results Out of the total 86 renal units , SDRC showed VUR in 22 , whereas VCU showed VUR in 29 . The SDRC and VCU results were concordant in 77 ( 90 % ) out of 86 renal units in the detection of VUR . The sensitivity , specificity , positive predictive value , and negative predictive value of SDRC when compared to VCU were 75.86 % , 100 % , 100 % and 89 % , respectively . The overall accuracy of SDRC was 91.86 % . Conclusions The supra-pubic direct radionuclide cystography is a simple technique for detecting as well as grading VUR . The technique avoids catheterization , is well tolerated by children and is without significant side effects BACKGROUND This study was design ed to examine the capability of renal ultrasonography ( US ) for predicting vesicoureteral reflux ( VUR ) and renal scarring ( RS ) , and to assess , using initial US , the significant urologic abnormalities that impact on management of children hospitalized with a first febrile urinary tract infection ( UTI ) . METHODS Hospitalized children aged ≤ 2 years with a first febrile UTI were prospect ively evaluated using imaging studies , including (99m)Tc dimercaptosuccinic acid ( DMSA ) scan , US , and voiding cystourethrography . RESULTS Of the 310 children analyzed ( 195 boys and 115 girls ) , 105 ( 33.9 % ) had abnormal US . Acute DMSA scans were abnormal in 194 children ( 62.6 % ) , including 89 ( 45.9 % ) with concomitant abnormal US . There was VUR in 107 children ( 34.5 % ) , including 79 ( 25.5 % ) with Grade s III-V VUR . The sensitivity and negative predictive values of US were 52.3 % and 75.1 % , respectively , for Grade s I-V VUR and 68.4 % and 87.8 % , respectively , for Grade s III-V VUR . Eighty-five children ( 27.4 % ) had RS , including 55 ( 64.7 % ) with abnormal US . Of the 105 children with abnormal US , 33 ( 31.4 % ) needed subsequent management ( surgical intervention , parental counseling , or follow up of renal function ) . Nephromegaly on initial US and Grade s III-V VUR were risk factors of RS . CONCLUSION Abnormal US may carry a higher probability of Grade s III-V VUR and RS , and can affect subsequent management in a significant number of children . Nephromegaly on initial US and Grade s III-V VUR are strongly associated with an increased risk for RS . Thus , US should be performed on children after a first febrile UTI and children with normal US may not require voiding cystourethrography PURPOSE We investigated the prevalence and types of lower urinary tract dysfunction in children with vesicoureteral reflux grade s III and IV , and related improved dilating reflux , renal damage and recurrent urinary tract infection to dysfunction . MATERIAL S AND METHODS A total of 203 children between ages 1 to less than 2 years with reflux grade s III and IV were recruited into this open , r and omized , controlled , multicenter study . Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done at study entry and 2-year followup . Lower urinary tract function was investigated by noninvasive methods , at study entry with 4-hour voiding observation in 148 patients and at 2 years by 
    Output:
    
EVIDENCE SYNTHESIS Conventional US can not replace voiding cystourethrography in the detection of VUR .
Contrast enhanced voiding sonography and direct radionuclide cystography suggest acceptable detection rates of VUR with sensitivity of 71 - 100 % and specificity of 67 - 100 % .
Renal US and diuretic radioisotope renography with choice of technetium99 m mercaptocetyltriglycine are invaluable imaging modalities for the detection of UPJO .
Despite the concerns about the invasiveness and radiation exposure of conventional voiding cystourethrography , it is still the gold st and ard technique in the detection of VUR and is superior to the other options in depiction of anatomical details .
US and mercaptocetyltriglycine scintigraphy are also the gold st and ards and will continue to be so in the diagnosis of UPJO .
PATIENT SUMMARY New imaging modalities such as contrast enhanced voiding sonography and direct radionuclide cystography are promising in the detection of vesicoureteral reflux .