***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE : To evaluate the yield , economic , and radiation costs of 5 diagnostic algorithms compared with a protocol where all tests are performed ( ultrasonography scan , cystography , and late technetium99dimercaptosuccinic acid scan ) in children after the first febrile urinary tract infections . METHODS : A total of 304 children , 2 to 36 months of age , who completed the diagnostic follow-up ( ultrasonography , cystourethrography , and acute and late technetium99dimercaptosuccinic acid scans ) of a r and omized controlled trial ( Italian Renal Infection Study 1 ) were eligible . The guidelines applied to this cohort in a retrospective simulation were : Melbourne Royal Children ’s Hospital , National Institute of Clinical Excellence ( NICE ) , top down approach , American Academy of Pediatrics ( AAP ) , and Italian Society of Pediatric Nephrology . Primary outcomes were the yield of abnormal tests for each diagnostic protocol ; secondary outcomes were the economic and radiation costs . RESULTS : Vesicoureteral reflux ( VUR ) was identified in 66 ( 22 % ) children and a parenchymal scarring was identified in 45 ( 15 % ) . For detection of VUR ( 47/66 ) and scarring ( 45/45 ) , the top down approach showed the highest sensitivity ( 76 % and 100 % , respectively ) but also the highest economic and radiation costs ( € 52 268 . 624 mSv ) . NICE ( 19/66 ) and AAP ( 18/66 ) had the highest specificities for VUR ( 90 % ) and the Italian Society of Pediatric Nephrology had the highest specificity ( 20/45 ) for scars ( 86 % ) . NICE would have been the least costly ( € 26 838 ) and AAP would have result ed in the least radiation exposure ( 42 mSv ) . CONCLUSIONS : There is no ideal diagnostic protocol following a first febrile urinary tract infection . An aggressive protocol has a high sensitivity for detecting VUR and scarring but carries high financial and radiation costs with question able benefit Abstract . We attempted to verify in a group of 101 children with first urinary tract infection whether it was possible to identify groups of patients with different risks of developing renal scarring by taking into account both the extent of kidney involvement documented in the acute phase of infection using a dimercaptosuccinic acid ( DMSA ) scan , and the presence or absence of vesicoureteral reflux ( VUR ) . The frequency of persistent lesions in kidneys with mild-moderate lesions ( less than 50 % of kidney involvement ) in the presence of VUR or in non-refluxing kidneys was similar ( P=0.1447 ) , while the frequency of persistent lesions in kidneys with severe lesions in the presence of VUR was significantly higher than the frequency of persistent lesions in non-refluxing kidneys ( P=0.0089 ) . The extent of kidney involvement and the presence of VUR make possible the identification of different categories of risk of scarring : in the ” low risk group ” ( normal kidney with/without VUR ) the risk of scarring is 0 % ; in the ” intermediate risk group ” ( mild lesions with/without VUR ; extensive lesions without VUR ) the risk of scarring is between 14 % and 38 % , while in the ” high risk group ” ( extensive lesions with VUR ) the risk of scarring is 88 % . Quantifying the risk of scarring could help in planning the treatment or in modifying the later strategy BACKGROUND Guidelines from the American Academy of Pediatrics recommend obtaining a voiding cystourethrogram and a renal ultrasonogram for young children after a first urinary tract infection ;  renal scanning with technetium-99m-labeled dimercaptosuccinic acid has also been endorsed by other authorities . We investigated whether imaging studies altered management or improved outcomes in young children with a first febrile urinary tract infection . METHODS In a prospect i ve trial involving 309 children ( 1 to 24 months old ) , an ultrasonogram and an initial renal scan were obtained within 72 hours after diagnosis , contrast voiding cystourethrography was performed one month later , and renal scanning was repeated six months later . RESULTS The ultrasonographic results were normal in 88 percent of the children ( 272 of 309 ) ; the identified abnormalities did not modify management . Acute pyelonephritis was diagnosed in 61 percent of the children ( 190 of 309 ) . Thirty-nine percent of the children who underwent cystourethrography ( 117 of 302 ) had vesicoureteral reflux ; 96 percent of these children ( 112 of 117 ) had grade I , II , or III vesicoureteral reflux . Repeated scans were obtained for 89 percent of the children ( 275 of 309 ) ; renal scarring was noted in 9.5 percent of these children ( 26 of 275 ) . CONCLUSIONS An ultrasonogram performed at the time of acute illness is of limited value . A voiding cystourethrogram for the identification of reflux is useful only if antimicrobial prophylaxis is effective in reducing reinfections and renal scarring .  Renal scans obtained at presentation identify children with acute pyelonephritis , and scans obtained six months later identify those with renal scarring . The routine performance of urinalysis , urine culture , or both during subsequent febrile illnesses in all children with a previous febrile urinary tract infection will probably obviate the need to obtain either early or late scans BACKGROUND Antibiotics are widely administered to children with the intention of preventing urinary tract infection , but adequately powered , placebo-controlled trials regarding efficacy are lacking . This study from four Australian centers examined whether low-dose , continuous oral antibiotic therapy prevents urinary tract infection in predisposed children . METHODS We r and omly assigned children under the age of 18 years who had had one or more microbiologically proven urinary tract infections to receive either daily trimethoprim-sulfamethoxazole suspension ( as 2 mg of trimethoprim plus 10 mg of sulfamethoxazole per kilogram of body weight ) or placebo for 12 months . The primary outcome was microbiologically confirmed symptomatic urinary tract infection . Intention-to-treat analyses were performed with the use of time-to-event data . RESULTS From December 1998 to March 2007 , a total of 576 children ( of 780 planned ) underwent r and omization . The median age at entry was 14 months ; 64 % of the patients were girls , 42 % had known vesicoureteral reflux ( at least grade III in 53 % of these patients ) , and 71 % were enrolled after the first diagnosis of urinary tract infection . During the study , urinary tract infection developed in 36 of 288 patients ( 13 % ) in the group receiving trimethoprim-sulfamethoxazole ( antibiotic group ) and in 55 of 288 patients ( 19 % ) in the placebo group ( hazard ratio in the antibiotic group , 0.61 ; 95 % confidence interval , 0.40 to 0.93 ; P = 0.02 by the log-rank test ) . In the antibiotic group , the reduction in the absolute risk of urinary tract infection ( 6 percentage points ) appeared to be consistent across all subgroups of patients ( P > or = 0.20 for all interactions ) . CONCLUSIONS Long-term , low-dose trimethoprim-sulfamethoxazole was associated with a decreased number of urinary tract infections in predisposed children . The treatment effect appeared to be consistent but modest across subgroups . ( Australian New Zeal and Clinical Trials Registry number , ACTRN12608000470392 . A prospect i ve blind study comparing the findings of ultrasonography , intravenous pyelography , and voiding cystourethrography was conducted on 81 patients to examine the place of ultrasonography in the initial radiologic evaluation of children with urinary tract infection . The patients ' mean age was 4.8 years ; 15 were male . Forty-eight were in patients ( mean age , 3.2 years ) and 33 were out patients ( mean age 7.2 years ) . In 29 patients ( 35.8 % ) abnormality of the urinary system was detected by one or more of the three imaging procedures ; 21 were in patients and eight were out patients . The most frequent finding was vesicoureteral reflux , occurring in 62.1 % of the pathologic cases . The findings at ultrasonography correlated well with those of intravenous pyelography in 73 of the 81 studies ( 90.1 % ) , but they failed to demonstrate double collecting systems and several of the minor changes . However , ultrasonography in combination with cystourethrography identified all patients who had abnormal urinary systems , except for two children with negligible findings . Moreover , ultrasonography and cystourethrography together identified all 11 patients , nine of them in patients , in whom surgical treatment was indicated . It is concluded that ultrasonography can successfully replace intravenous pyelography as a screening imaging procedure for the urinary system , but because of the superiority of intravenous pyelography in the detection of some types of lesions , intravenous pyelography will be required whenever ultrasonography or cystourethrography results are abnormal . ( ABSTRACT TRUNCATED AT 250 WORDS OBJECTIVE 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 . STUDY DESIGN We observed prospect ively 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 . RESULTS 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 . CONCLUSION 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 This prospect i ve study was done to assess the frequency of acute pyelonephritis ( APN ) in febrile children with positive urine culture as documented by Tc99 m DMSA scintigraphy ( DMSA )  and the frequency of vesicoureteric reflux ( VUR ) in these children . Secondly , to determine the frequency of APN , in febrile children with supportive evidence for UTI but with negative urine culture , as documented by DMSA and frequency of VUR in them . Thirdly to stress the utility of DMSA to diagnose APN in urine culture negative febrile children and to suggest DMSA as a clinical tool in evaluation of fever of unknown origin ( FUO ) . This study included 42 children with positive urine culture and 26 children with negative urine culture who had supportive evidence of UTI as determined by the predetermined criteria and diagnosed to have APN by DMSA . All of them had ultrasonogram ( USG ) , DMSA and voiding cystourethrogram ( VCU ) . They were followed up for a minimum period of 6 months . Out of the 42 children with positive urine culture 92.9 % had features of APN in the DMSA of whom 82.1 % had vesicoureteric relux ( VUR ) . The DMSA was abnormal in 26 children with negative urine culture , of whom 65.4 % had VUR . Ultrasound suggestive of parenchymal change was observed in 47.6 % in the culture positive group and 65.4 % in the culture negative group . In conclusion , it is suggested , that DMSA is a useful investigation for the diagnosis of APN in febrile UTI . DMSA is indicated in febrile children with negative urine culture but with supportive evidence of UTI and in FUO . An abnormal DMSA is a strong indication for work up for VUR We assessed the role of therapeutic delay time ( TDT ) in acute renal cortical scintigraphic lesion ( ASL ) and ultimate scar formation ( USF ) in children with first febrile UTI and whether it is affected by the presence of vesico-ureteral reflux ( VUR ) . 230 children , 90 girls and 140 boys with first febrile UTI were included . Radiologic ( USG , DMSA , and VCUG ) , clinical ( age , gender , peak fever , therapeutic delay time ) and laboratory ( CBC with differential count , ANC ( absolute neutroph 
    Output:
    
Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR ( of all grade s ) .
Although a child with a negative DMSA test has an < 1 % probability of having high- grade VUR , performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high- grade VUR .