Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 2: Scarring

Guidelines for Complicated Urinary Tract Infections in Children: A Review by the European Society for Pediatric Infectious Diseases

BACKGROUND

Complicated urinary tract infections (cUTI) present a challenge to the clinician because of the variety in clinical syndromes included and consequent difficulties in synthesizing evidence. A harmonized definition of cUTI does not exist. In national guidelines, management recommendations for cUTI are often neglected. We aimed to define the four most important controversies and formulate management recommendations for cUTI in children and adolescents.

METHODS

The European Society of Pediatric Infectious Diseases Guideline Committee convened a working group of experts from microbiology, pediatric nephrology and infectious diseases with expertise in managing children with UTI. A comprehensive literature review was done using PubMed, Embase and the Cochrane library to find studies in children under 18 years published until December 2024. Four controversies were defined from experience and available evidence. Children with cUTI were categorized into 5 subgroups: anatomical/functional urological abnormalities, multiple UTI recurrences, severe clinical presentation, nonurological underlying conditions and neonates. Respective management guidelines were formulated through the evidence and by consensus of working group members. Recommendations were made using GRADE criteria.

RESULTS

The term cUTI is generally used to define children with UTI with an increased likelihood of failing conventional management. The included 5 subgroups are the most likely to need additional investigations at diagnosis and during the course of infection, initial intravenous antibiotics, longer treatment duration, antibiotic prophylaxis, follow-up imaging and surgical referral. These are detailed for each subgroup.

CONCLUSIONS

These comprehensive guidelines offer evidence-graded recommendations specifically for pediatric cUTI, addressing gaps that exist in current guidelines.

'Targeted top down' approach for the investigation of UTI: A 10-year follow-up study in a cohort of 1000 children

INTRODUCTION

Investigations following urinary tract infection (UTI) aim to identify children who are prone to renal scarring, which may be preventable. In 2002, in an attempt to reduce unnecessary intervention, the present institution standardised the investigation of children with a confirmed UTI.

OBJECTIVE

This study aimed to identify the significance of urological abnormalities on investigations following a UTI in children, prior to the introduction of the National Institute for Health and Care Excellence (NICE) guidelines.

METHODS

Clinical information on the first 1000 patients was retrieved from a prospective UTI hospital database. The follow-up period was 10 years.

RESULTS

There were 180 males and 820 females (M:F = 1:4.5). The median age of presentation was 5 years (range 11 days-16 years). A renal ultrasound (US) was performed on all patients, and was normal in 93% of cases (n = 889) (see Figure). Of the 7% who had an abnormal US (n = 71), 54 were female and 17 male (M:F = 1:3). A total of 372 DMSA scans were requested and 350 attended their appointment. Of these, 278 cases (79%) were reported as normal, while 72 had an abnormality documented. Of these 72 patients with abnormalities on DMSA scan, 49 had a repeat DMSA scan: 30 demonstrated permanent scarring, while the DMSA scan became normal in 19. Sixteen of the 278 patients whose DMSA scan was initially normal had a repeat DMSA scan due to symptoms, and all scans were normal. Twelve (1.2%) patients required surgical intervention: three underwent circumcision for recurrent UTIs; three underwent endoscopic treatment of VUR; one had a PUV resection; one underwent a cystoscopy; three had a pyeloplasty for pelvi-ureteric junction obstruction; and one had a ureteric reimplantation for vesico-ureteric junction obstruction. After initial investigations and management, 936 patients were discharged from the UTI clinic: 47 of them re-presented - 40 with recurrent UTIs and seven with dysuria. Thirty-five of the 47 children who re-presented with urological symptoms underwent a DMSA scan, which showed scarring in three (6%).

DISCUSSION

Only 12% of children have a significant radiological abnormality picked up on investigation following a UTI. The present investigation approach differed from the NICE guidelines, where imaging is based on patient age and characteristics of the UTI. All children had a renal US, while DMSA scans were reserved for those children <1 year of age or those with upper tract symptoms. The present protocol recommended a renal US in all children presenting with a UTI. This promptly identified those with pelvi-ureteric junction obstruction and those with PUV, who all presented >6 months of age with a single UTI and, therefore, based on the NICE guidelines would not have undergone a renal US. Of the children who re-presented with further UTIs, a significant number were found to have dysfunctional voiding. As this link is well reported, it may be appropriate to screen for this in older children at initial presentation. Only three patients, who had a US at presentation, were subsequently found to have scarring on DMSA. After 10 years of follow-up, this could represent a false negative rate of 0.3% for the screening programme. None of the girls were found to have VUR or needed any surgical intervention, which suggested that early identification of the scarring might not have altered management. Few patients required surgical intervention, all of whom were identified early. No patient who re-presented required intervention. This would suggest that the present protocol is effective at picking up abnormalities that require surgical management.

CONCLUSION

This study suggested that after a childhood UTI, the liberal use of renal ultrasound and a focused 'top down' approach to investigation is likely to identify the vast majority of children who require intervention.

Urinary tract infection in children: recurrent infections

INTRODUCTION

Up to 11% of girls and 7% of boys will have had a urinary tract infection (UTI) by the age of 16 years, and recurrence of infection is common. Vesicoureteric reflux (VUR) is identified in up to 40% of children being investigated for a first UTI, and is a risk factor for, but weak predictor of, renal parenchymal defects.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of prophylactic antibiotics to prevent recurrent urinary tract infection in children? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review).

RESULTS

We found three studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following intervention: prophylactic antibiotics.

Comparison of magnetic resonance urography to dimercaptosuccinic acid scan for the identification of renal parenchyma defects in children with vesicoureteral reflux

OBJECTIVE

The objective of this study was to compare the accuracy of dimercaptosuccinic acid (DMSA) renal scan to magnetic resonance urography (MRU) in the identification of renal parenchyma defects (RPD).

MATERIALS AND METHODS

Twenty-five children with history of acute pyelonephritis and vesicoureteral reflux underwent DMSA scan and MRU to determine the presence of RPD. DMSA scans and MRUs were each evaluated by two radiologists and agreement achieved by consensus. Discordant DMSA-MRU findings were re-evaluated in a side-by-side comparison and an ultimate consensus reached.

RESULTS

The ultimate consensus diagnosis was 18 kidneys with RPDs in 15 patients, of which five were classified as mild RPDs, six as moderate RPDs, and seven as severe RPDs. Although DMSA scan and MRU were similar in their ability to diagnose RPDs, MRU was considered to represent the true diagnosis in 11 of the 12 discordant cases in consensus review by four pediatric radiologists. MRU showed a much higher inter-observer agreement with a weighted kappa of 0.96 for both kidneys compared to 0.71 for the right kidney and 0.86 for the left kidney by DMSA scan.

CONCLUSIONS

Our results suggest that MRU is superior to DMSA scan in the identification of renal parenchyma defects.

[Primary vesicoureteral reflux]

The never ending discussion about the diagnostics and treatment of vesicoureteral reflux (VUR) now includes arguments for diagnostic nihilism as well as invasive diagnostics and therapy, which is reminiscent of the debate on prostate cancer in adulthood. The common goal of all currently competing diagnostic strategies and approaches is the prevention of renal scars by the most effective and least burdensome approach. There is a difference between acquired pyelonephritic scars with VUR (acquired reflux nephropathy) and congenital reflux nephropathy (primary dysplasia) which cannot be influenced by any therapy.The VUR can be verified by conventional radiological voiding cystourethrography (VCUG), by urosonography, radionuclide cystography or even by magnetic resonance imaging (MRI). The guidelines of the European Association of Urology/European Society for Paediatric Urology (EAU/ESPU) recommend radiological screening for VUR after the first febrile urinary tract infection. Significant risk factors in patients with VUR are recurrent urinary tract infections (UTI) and parenchymal scarring and the patients should undergo patient and risk-adapted therapy. Infants with dilating reflux have a higher risk of renal scarring than those without dilatation of the renal pelvis. Bladder dysfunction or dysfunctional elimination syndrome represents a well-known but previously neglected risk factor in combination with VUR and should be treated prior to any surgical intervention as far as is possible.Certainly not every patient with VUR needs therapy. The current treatment strategies take into account age and gender, the presence of dysplastic or pyelonephritic renal scars, the clinical symptoms, bladder dysfunction and frequency and severity of recurrent UTI as criteria for the therapy decision. The use of an antibacterial prophylaxis as well as the duration is controversially discussed. Endoscopic therapy can be a good alternative to antibacterial prophylaxis or a surveillance strategy in patients with low grade VUR. In patients with dilating VUR and given indications for surgery, endoscopic treatment can be offered. However, parents should be completely informed about the significantly lower success rate of endoscopic therapy compared to open surgical procedures. The open surgical techniques guarantee the highest success rates and should be used in patients with a dilating VUR and high risk of renal damage.

Diagnostic accuracy of magnetic resonance voiding cystourethrography for detecting vesico-ureteral reflux in children and adolescents

BACKGROUND

The purpose of the present study is to determine the accuracy of magnetic resonance voiding cystourethrography (MRVCUG) for diagnosis of vesicoureteral reflux (VUR) in children and adolescents with recurrent urinary tract infection (UTI).

MATERIALS AND METHODS

During the cross-sectional study from May 2009 to June 2011, 30 patients' (60 kidney-ureter units) MRVCUG findings by 1.5 T magnetic resonance imaging (MRI) were compared with voiding cystourethrography (VCUG) findings in patients with urinary tract infection. The sensitivity, specificity, positive and negative predictive values for MRVCUG were calculated.

FINDINGS

The sensitivity, specificity, positive and negative predictive values and accuracy for MRVCUG for detecting VUR were respectively 92.68% (95% CI: 80.57-97.48%), 68.42% (95% CI: 46.01-84.64%), 86.36% (95% CI: 71.95-94.33%), 81.25% (95% CI: 53.69-95.02%), and 85% (95% CI: 80.40-89.60%. The level of agreement between MRVCUG and VCUG findings for diagnosis VUR was very good (P < 0.001, according to Cohen's kappa value = 0.638). Studying correlation of low grade VUR (grade I and II) and high grade VUR (grade III-V) showed a very good agreement between MRVCUG and VCUG findings (P < 0.001, Cohen's kappa value = 0.754).

CONCLUSION

MRVCUG could accurately reveal the presence and severity of VUR, especially in cases with high-grade (grade III-V) VUR in both children and adolescents.

The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood

OBJECTIVE

The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI.

METHODS

A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97 ± 1.57 years (0.02-7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI.

RESULTS

Of 67 children, 17 (25.4%), 23 (34.3%) and 20 (29.9%) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and < 0.001 in patients and at p values 0.024 and < 0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I-III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV-V) had significant correlations with abnormal DMSA renal scintigraphy at p values < 0.001 and < 0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2%) developed persistent renal scarring.

CONCLUSION

Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first episode of UTI should be carried out in those patients. Abnormal DMSA renal scintigraphy at 1 month after UTI has a tendency to persist.

Childhood recurrent urinary tract infection in southern Thailand

INTRODUCTION

Recurrent urinary tract infection (UTI) is one of the major health problems in children because of its high rate of occurrence.

OBJECTIVE

Our aim of the study was to evaluate the prevalence and determine risk factors of recurrent UTI in Thai children.

PATIENTS AND METHODS

The medical records of children aged less than 15 years diagnosed with UTI at the Department of Pediatrics, Songklanagarind Hospital were reviewed.

RESULTS

A total of 307 children (144 boys, 163 girls) were followed up for at least 1 year. Fifty-six children, 31 (19.0%) boys and 25 (17.4%) girls, developed at least one recurrence totaling 153 recurrent UTI episodes. The recurrence rate was not statistically different between the sexes (p = 0.8). On multivariate analysis, genitourinary system (GU) anomalies, particularly vesicoureteral reflux (VUR), were the most significant risk factors. Children aged greater than 5 years had a slightly higher risk of recurrence, irrespective of gender. Comparison of organisms associated with recurrent UTI with those associated with first UTI showed that the prevalence of Escherichia coli decreased from 76.9% to 56.2% but was still the major causative agent. In contrast, the prevalence of Klebsiella pneumoniae and unusual or mixed organisms significantly increased from 7.8% to 15.0% and 6.2% to 16.3%, respectively.

CONCLUSION

One-fifth of children who had UTI developed recurrence and the rates were similar for males and females. Independent risk factors for recurrent UTI were found to be at age of >5 years and underlying disease of either GU anomaly or VUR.

Abnormal dimercaptosuccinic Acid scan may be related to persistence of vesicoureteral reflux in children with febrile urinary tract infection

PURPOSE

This study assessed whether (99m)technetium dimercaptosuccinic acid (DMSA) scintigraphy used for the assessment of renal sequelae after febrile urinary tract infection (UTI) has any prognostic value for outcome measurement of vesicoureteral reflux (VUR) by retrospectively evaluating the correlation between abnormal DMSA scintigraphy results and persistence of VUR in children with febrile UTI.

MATERIALS AND METHODS

The medical records of 142 children (57 boys, 85 girls) admitted with febrile UTI from January 2004 to December 2006 and who were followed up for more than 1 year were retrospectively reviewed. At the initial and follow-up visits, renal ultrasound and DMSA scans were performed within 7 days from the diagnosis and voiding cystourethrography (VCUG) was performed within 1 month in all case and follow-up evaluations.

RESULTS

The children's mean age was 4.8±3.6 years (range, 0.3 to 14 years). The mean follow-up was 28.2±4.8 months. At the initial examination, VUR was more often associated with an abnormal DMSA scan result (83.3%) than with a normal DMSA scan result (16.7%, p=0.02). The frequency of VUR with an abnormal DMSA scan during acute UTI was significantly higher than the frequency of VUR with a normal DMSA scan (38.8% vs, 25.8%, respectively, p=0.004). Also, high-grade VUR was associated with an abnormal DMSA scan result (32.5%) more often than with a normal DMSA scan result (0%, p=0.01). Children with an abnormal DMSA scan had a lower resolution rate of VUR (17.5%) than did children with a normal DMSA scan (75.0%) at the follow-up VCUG (p=0.02).

CONCLUSIONS

An abnormal result on a DMSA scan during febrile UTI is associated with high-grade and persistent VUR. DMSA scans performed during febrile UTI are useful in reflux resolution in childhood.

[Therapeutic options for primary vesicoureteral reflux: endoscopic vs open surgical approach]

Therapy of vesicoureteral reflux (VUR) has steadily changed during the last decade. Open surgical procedures, e.g. extravesical reflux repair with the Lich-Gregoir technique or ureterocystoneostomy with the psoas hitch technique, reference standards with excellent success rates, are less frequently used. Since its approval by the US Food and Drug Administration (FDA) endoscopic reflux therapy with Deflux® has gained more and more popularity. However, the usage of so-called bulking agents, e.g. Deflux®, still remains controversial in dilating reflux, while its application for low-grade VUR is increasingly being accepted. Despite higher recurrence rates in all grades of VUR, the use of the "minimally invasive injection" is increasing. The question has to be answered which therapy - if necessary - benefits the patient most. Which role has the subureteral injection gained and are open surgical procedures for VUR therapy "out"?

Demographic features and antibiotic resistance among children hospitalized for urinary tract infection in northwest Iran

Introduction:

Urinary tract infection (UTI) is the most common serious bacterial infection during infancy. The aim of the present study was to evaluate demographic characteristics, clinical presentations and findings, and antimicrobial resistance among infants and children hospitalized in Tabriz Children’s Hospital, Tabriz, Iran.

Methods:

In this descriptive observational study, 100 children who had been admitted with UTI diagnosis to Tabriz Children’s Hospital from March 2003 to March 2008 were studied. Demographic characteristics, chief complaints, clinical presentations and findings, urine analysis and cultures, antimicrobial resistance, and sonographic and voiding cystourethrographic reports were evaluated.

Results:

The mean age of patients was 35.77 ± 39.86 months. The male to female ratio was 0.26. The mean white blood cell count was 12,900 ± 5226/mm³. Sixty-two percent of patients had leukocytosis. The most common isolated pathogen was Escherichia coli spp (77%) followed by Klebsiella spp (10%), Enterobacter spp (9%), and Enterococcus spp (4%). Isolated pathogens were highly resistant to ampicillin, cotrimoxazole, and cephalexin (71%–96%), intermediate sensitivity to third-generation cephalosporins, and highly sensitive to ciprofloxacin (84.4%), amikacin (83.8%), and nitrofurantoin (82.8%).

Conclusion:

The most common pathogen of UTI in the hospitalized children was E. coli spp. The isolated pathogens were extremely resistant to ampicillin, and highly sensitive to ciprofloxacin and amikacin.

Urinary tract infection in children

INTRODUCTION

Up to 11.3% of girls and 3.6% of boys will have had a urinary tract infection (UTI) by the age of 16 years, and recurrence of infection is common. Vesicoureteric reflux is identified in up to 40% of children being investigated for a first UTI, and is a risk factor for, but weak predictor of, renal parenchymal defects.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatment of acute urinary tract infection in children? What are the effects of interventions to prevent recurrence? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 25 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics (short initial intravenous antibiotics, long initial intravenous antibiotics, initial oral antibiotics, single-dose or single-day courses of oral antibiotics, short courses of oral antibiotics, long courses of oral antibiotics, immediate empirical antibiotics, delayed antibiotics, prolonged delay of antibiotics, prophylactic antibiotics); immunotherapy; surgical correction of minor functional abnormalities; and surgical correction of moderate to severe vesicoureteric reflux.

Sensitivity of ultrasonography in detecting renal parenchymal defects: 6 years' follow-up

While (99m)Tc-dimercaptosuccinic acid (DMSA) scanning is still considered the most accurate method for the assessment of renal parenchymal defects (RPDs), our study 6 years previously suggested that ultrasonography (US) could be a safe and efficient substitute for this purpose, provided that it is reliably performed and that renal function parameters are followed. By comparison of the original and follow-up study data from 67 children, the accuracy of our recommendations was re-evaluated. US was performed and renal function parameters investigated and correlated to the DMSA scans from the original study. US identified all six patients with clinically significant RPD and 52/61 with clinically insignificant RPDs, seen on the DMSA scans. Twenty two out of 22 severe RPDs, 21/23 moderate RPDs and 20/40 mild RPDs seen on the DMSA scans were detected by US. In ten cases normal US findings from the original study were rendered abnormal, correlating well with the DMSA scans with respect to RPD localization and kidney size. These results further support our previous suggestion that US is a safe and harmless alternative to DMSA scanning in the detection and follow-up of RPDs. While it cannot be excluded that small RPDs missed on the initial US might 'develop' clinical significance in later life, children with normal findings on initial US should have another sonogram done, at the shortest a year later, together with an investigation of renal function parameters.

Pyelonephritis, renal scarring, and reflux nephropathy: a pediatric urologist's perspective

Imaging of children with a clinical diagnosis of pyelonephritis is performed to characterize the extent of the infection, to identify associated renal injury and to uncover risk factors for future infections and renal damage. Although there is general agreement regarding the need for parenchymal imaging and the need to exclude processes that are either functionally or anatomically obstructive, there is controversy regarding the need for routine cystography, especially when parenchymal involvement has not been documented. A protocol that limits the use of cystography for evaluation of urinary tract infections must assume that the diagnosis of reflux is at least of variable clinical significance. It is now clear that vesicoureteral reflux and reflux nephropathy represent a diverse population that includes both congenital and acquired processes. MR imaging will improve our understanding of vesicoureteral reflux, pyelonephritis and renal scarring and might help us to identify and manage those patients most at risk for recurrent infections and renal injury. To recognize the potential contributions of this newer imaging technique it is helpful to look at our understanding of the pathophysiology of pyelonephritis, reflux and reflux nephropathy.

Magnetic resonance voiding cystourethrography for vesicoureteral reflux

PURPOSE

To assess the feasibility of magnetic resonance voiding cystourethrography (MRVCUG) using MR fluoroscopy for evaluation of vesicoureteral reflux (VUR), and its use as a noninvasive alternative to standard VCUG.

MATERIALS AND METHODS

A total of 22 MR studies of 16 patients (five months to 41 years old) with primary VUR diagnosed by standard VCUG were evaluated. Six patients underwent MR studies and standard VCUG pre- and postoperatively. MR fluoroscopy was executed with a non-enhanced heavily T2-weighted single-shot fast spin-echo (FSE) sequence. The MR findings were correlated with those obtained by the gold standard, standard VCUG.

RESULTS

Of the 44 kidney-ureter units, 20 were refluxing on MRVCUG and 21 were refluxing on standard VCUG. There were one false-positive and two false-negative units. MRVCUG was 90% sensitive with a specificity of 96% for detecting VURs that were calculated based on kidney-ureter units. Two false-negative units were found in mild cases (grade I and II). For the units of grade III, IV, and V (high-grade reflux), MRVCUG detected all of the refluxing renal collecting systems.

CONCLUSION

MRVCUG can demonstrate high-grade reflux without ionizing radiation or catheterization.

The Efficacy of Tc99m Dimercaptosuccinic Acid (Tc-DMSA) Scintigraphy and Ultrasonography in Detecting Renal Scars in Children with Primary Vesicoureteral Reflux (VUR)

INTRODUCTION

Pyelonephritis-induced renal scarring in children is a major predisposing factor for proteinuria, hypertension, and ultimate renal failure. The aim of this study was to investigate and compare the efficacy of Tc99m dimercaptosuccinic acid (Tc-DMSA) renal scintigraphy and renal ultrasonography (USG) in detecting renal scars in children with primary vesicoureteral reflux (VUR).

MATERIALS AND METHODS

Tc-DMSA scan and USG studies were done in 62 children who were admitted to our clinic between 1997 and 2003 because of documented urinary tract infection (UTI) and diagnosed with primary VUR. Renal scarring detection rates of Tc-DMSA scan and USG were compared according to reflux grades.

RESULTS

In the whole group, renal scars were detected by Tc-DMSA scan and USG in 55% and 38% of refluxing units, respectively. Detection rates of Tc-DMSA and USG according to reflux grades were as follows: 47% and 29 % in low-grade VUR (grades 1 and 2), 46 % and 25% in mid-grade VUR (grade 3), 76% and 65% in high-grade VUR (grades 4 and 5), respectively.

CONCLUSION

USG was found to be an inappropriate study in the detection of renal parenchymal scars, irrespective of the reflux grade. In this study, Tc-DMSA scan detected scars in 35% of kidneys reported to be normal on USG.

May we go on with antibacterial prophylaxis for urinary tract infections?

Recurrent urinary tract infections (UTIs), with or without vesicoureteric reflux (VUR), are by far the most frequent reason for long-term antibacterial prophylaxis in infants and children today. However, the strategies of antibacterial prophylaxis for the prevention of recurrent urinary tract infection are no longer universally accepted. In infants and children at risk, the benefits of antibacterial prophylaxis definitively are not yet proven by evident data. To put antibacterial prophylaxis in its place, risk groups for recurrent symptomatic infections, ascending UTI and permanent renal damage have to be defined and the efficacy of prophylaxis in these groups has to be proved by prospective randomised studies. Nevertheless, until the results of these studies are available, antibacterial prophylaxis will remain one of the most frequently practised methods to protect risk patients from pyelonephritic damage and UTI recurrences.

Recent trends of genitourinary endoscopy in children

Downsizing and refinement of the pediatric endoscope in video-monitoring systems have facilitated genitourinary endoscopy even in small children without any traumatic instrumentation. Indications for endoscopy in children with hematuria or tractable urinary tract infection have been tailored for the rareness of genitourinary malignancy or secondary vesicoureteral reflux (VUR) as a result of infravesical obstruction. Most mechanical outlet obstructions can be relieved endoscopically irrespective of sex and age. Endoscopic decompression by puncture or incision of both intravesical and ectopic ureteroceles can be an initial treatment similar to open surgery for an affected upper moiety. Endoscopy is necessary following urodynamic study to exclude minor infravesical obstruction only in children with unexplained dysfunctional voiding. Genitourinary endoscopy is helpful for structural abnormalities before and at the time of repairing congenital urogenital anomalies. Endoscopic injection therapy of VUR has been established as a less invasive surgical treatment. Pediatric endoscopy will play a greater role in the armamentarium for most pediatric urological diseases through the analysis of visual data and discussion on the indications for endoscopy throughout the world.

Fluctuating fetal or neonatal renal pelvis: marker of high-grade vesicoureteral reflux

Fetal renal pelvic dilatation is a predictor of vesicoureteral reflux (VUR), but has low specificity. The aim of this study was to determine the clinical significance of fluctuating size of the renal pelvis on sonography, particularly in relationship to VUR. We prospectively recorded fetal renal pelvic diameter >/=4 mm in 1,092 fetuses (692 boys), from May 1989 to December 1995, with a minimum follow-up of 7 years. Fluctuation, defined as size of renal pelvis changing by more than 4 mm during the course of obstetric (23), postnatal (128), and both pre- and postnatal (7) renal sonograms, was recorded prospectively in 159 (117 boys). Of the 1,092, 849 (593 boys) had a voiding cystourethrogram at a mean age of 7 weeks (range 3-20 weeks). Of the 31 (16 girls) with high-grade VUR, fluctuation was observed in 20 (9 girls). Fluctuation was strongly associated with high-grade VUR (odds ratio 11.1, P=0.0000003) and with renal damage (sensitivity 61%, positive predictive value 31%). Primary high-grade VUR was persistent, seen equally in boys and girls, and required surgery in the majority. Fluctuation was associated with renal duplication anomalies ( P=0.00009) and megaureter ( P<0.00000001). Fluctuation of the renal pelvis on sonography is a marker for persistent high-grade VUR and renal damage in girls and boys.

Persistent renal cortical scintigram defects in children 2 years after urinary tract infection

BACKGROUND

Renal cortical scintigraphic studies challenge the role of vesicoureteric reflux in renal scar development, emphasizing instead the part played by acute pyelonephritis.

OBJECTIVE

To determine the prevalence of renal cortical defects in a child cohort 2 years after the child's first diagnosed urinary tract infection and to analyze the relationship of these defects with acute illness variables, primary vesicoureteric reflux and recurrent infections.

MATERIALS AND METHODS

In a prospective cohort study, 193 children younger than 5 years with their first proven urinary tract infection underwent renal sonography, voiding cystourethrogram, and renal cortical scintigraphy within 15 days of diagnosis. Two years later, 150 of the 193 children, or 77.7%, had a further renal cortical scintigram, including 75, or 86.2%, of the 87 children who had acute scintigraphic defects. The relationship of cortical defects to age, gender, pre-treatment symptom duration, hospitalization, presence and grade of vesicoureteric reflux, and recurrent urinary tract infections was evaluated.

RESULTS

Overall, 20 of the 150 (13.3%; 95% confidence interval (CI) 8.3, 19.8) children had persistent defects 2 years after infection. This included 20 of 75 (26.7%; 95% CI 17.1, 38.1) with initially abnormal scintigrams. No new defects were detected. Although acute defects were more common in the young, those with persistent defects were older (median ages 16.4 vs. 6.8 months, P=0.004) than those with transient abnormalities. After adjustment for age, persistent defects were no longer associated with gender and were not predicted by acute illness variables, primary vesicoureteric reflux or recurrent infections.

CONCLUSIONS

Renal cortical scintigraphic defects persisted in approximately one-quarter of young children after their first proven urinary tract infection. The associated clinical features, however, failed to predict scar formation. It is possible that some of the scintigraphic defects preceded the infection by arising from either previously undiagnosed acute pyelonephritis or from underlying congenital dysplasia. The etiology of scars may be best addressed by determining whether prevention of urinary tract infections from birth avoids post-natal scar acquisition or extension.

Utility of follow-up renal sonography in children with vesicoureteral reflux and normal initial sonogram

OBJECTIVE

The purpose of this study was to determine the value of follow-up renal sonography in children who presented with urinary tract infection and were found to have a voiding cystogram diagnosis of vesicoureteral reflux while having a normal initial renal sonogram.

METHODS

We retrospectively reviewed the medical records of 64 consecutive children who presented for follow-up renal sonography with a voiding cystogram diagnosis of vesicoureteral reflux and a normal initial sonogram conducted as part of the routine evaluation after urinary tract infection. Data recorded included gender, age, initial grade of reflux, time to follow-up sonogram, and abnormalities on follow-up sonogram. Children with conditions that may predispose to vesicoureteral reflux were excluded.

RESULTS

Children who were studied (7 boys, 57 girls) ranged in age from 1 month to 10 years, 10 months (mean: 35.6 months; median: 24 months). Ninety-four (73.4%) of 128 renal units demonstrated vesicoureteral reflux on voiding cystogram; 89 (94.7%) of 94 of them were grade 1 to 3. The mean time to follow-up was 22 months (range: 4 months to 5 years, 2 months; median: 18 months). All 128 (95% confidence interval: 0%-2.8%) renal units were normal on follow-up sonography.

CONCLUSION

Routine performance of repeat sonography seems unnecessary among children, particularly girls, with low- to medium-grade vesicoureteral reflux, who have had a previous normal sonogram and no conditions that predispose to vesicoureteral reflux.

DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.

Ultrasonography in the evaluation of renal scarring using DMSA scan as the gold standard

Dimercaptosuccinic acid (DMSA) renal scan is presently the technique of choice for assessing renal scars. Recent advances suggest that ultrasonography could replace DMSA scan for this purpose. This paper describes the experience of a tertiary pediatric referral hospital performing ultrasonography and DMSA scans in the assessment of renal scarring. Investigations were conducted 3-6 months after patients presented with urinary tract infection (UTI). Results were extracted from the radiology information system and recorded for analysis. All children with a UTI who had undergone DMSA and ultrasound examination on the same day between January 1995 and December 1999 were included; 930 kidneys were compared. DMSA scan was utilized as the reference method. When used to detect focal renal scarring, ultrasonography had a sensitivity of 5.2%, specificity of 98.3%, a positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 75.8%. When used to detect diffuse renal scarring, ultrasonography had a sensitivity of 47.2%, specificity of 91.8%, PPV of 60.8% and NPV of 86.6%. Our results demonstrate that although ultrasonography has a good specificity for the detection of renal scarring compared with DMSA, it has low sensitivity, PPV and NPV. Ultrasonography cannot be substituted for DMSA scan in the evaluation of focal renal scarring.

Nuclear medicine studies in the dialysis patient

Nuclear medicine (scintigraphy) studies that are performed in patients being prepared for regular dialysis treatment include the measurement of renal clearance and dynamic studies of renal perfusion and function. Static scintigraphy with 99mTc-DMSA may be used in the evaluation of children at risk of renal damage and further functional deterioration. In patients on peritoneal dialysis, nuclear medicine procedures enable the diagnosis of structural complications such as intra-abdominal herniations and leaks. Diagnosis of infections of the vascular access sites in patients on hemodialysis and of the catheter tunnel in patients on peritoneal dialysis can be made with high diagnostic accuracy using radiolabeled, autologous leukocytes. Scintigraphy is valuable in delineating the extent of deposits of amyloid and parenchymal microcalcifications, and may be helpful in the functional evaluation of organs and tissues involved in the pathophysiology of renal impairment and dialysis. If radioiodine therapy with 131I is performed in patients on hemodialysis with benign or malignant thyroid disease, then pretherapeutic dosimetry is necessary to avoid over- and undertreatment. Radioiodine therapy in the dialysis patient leads to only insignificant contamination of dialysis equipment and marginal exposure to the medical staff.

Follow-up of acute pyelonephritis in children by Tc-99m DMSA scintigraphy: quantitative and qualitative assessment

PURPOSE

The author's goal was to create a system to identify children at risk for development of progressive renal damage.

METHODS

Thirty-four children were examined with Tc-99m DMSA scintigraphy in the acute stage of an initial episode of pyelonephritis, after 6 months, and again after 1 year. The scintigraphic findings were correlated with clinical and laboratory data.

RESULTS

All children had parenchymal defects in the acute stage: 93% of the kidneys and 85% bilaterally. After 6 months, the defects had diminished or disappeared in 66% of the kidneys. New defects appeared in 22%. At 1 year, no further improvement was seen in the kidneys, with an improved or unchanged pattern at 6 months. New defects appeared in 34%. Mean kidney activity uptake expressed as the percentage of administered dose (KU/AD), was low in the acute stage, increased at 6 months, with no further significant increase at 1 year. Eighty-three percent of children with urine cultures growing > or = 104 bacteria/ml at follow-up had decreased KU/AD values, whereas all children with urine cultures growing < 104 bacteria/ml had increased KU/AD values.

CONCLUSIONS

Quantitative assessment increases the sensitivity of Tc-99m DMSA scintigraphy. Follow-up with this method makes it possible to identify the children with decreasing renal tubular function who may be at risk for progressive renal damage. Moderate bacteruria of 104 bacteria/ml urine is associated with deterioration of renal tubular function.

UTI: diagnosis and evaluation in symptomatic pediatric patients

We retrospectively reviewed data on 260 hospitalized pediatric patients with symptomatic urinary tract infection (UTI). To ascertain the colony-forming units (CFU)/mL compatible with the diagnosis of UTI, a culture from a catheterized urine specimen containing >1,000 CFU/mL was considered diagnostic of UTI and resulted in imaging by renal ultrasound, voiding cystourethrography, and renal nuclear scan with Tc99m dimercaptosuccinic acid (DMSA). A positive DMSA renal scan is indicative of pyelonephritis. We used logistic regression analysis to determine which patient characteristics were predictive of pyelonephritis. We determined that, in hospitalized pediatric patients, the colony count of the positive urine culture, the type of organism grown in culture, and the voiding cystourethrography (VCUG) result (positive or negative for vesicoureteral reflux) did not predict which patients had pyelonephritis. In females, advancing age of the patient and positive renal ultrasound results were predictive of which patients had pyelonephritis when we controlled for other factors. We feel this emphasizes the importance of a thorough evaluation of hospitalized symptomatic patients, including patients with colony counts of 1,000 to 50,000 CFU/mL, to locate the level of infection and plan appropriate therapy.

Risk assessment of renal cortical scarring with urinary tract infection by clinical features and ultrasonography

AIMS

To address some of the issues in the ongoing debate over the optimal diagnostic imaging following childhood urinary tract infection (UTI), by determining the risk of missing renal cortical scarring which would be detected on a technetium-99m dimercaptosuccinic acid (DMSA) gold standard if ultrasound alone were used, factoring for clinical features (upper or lower tract), UTI recurrence, and age group (infants, preschool, or school age).

METHODS

Details of UTI clinical features and recurrence were recorded for 990 children with a proven UTI, and their DMSA and ultrasound results were compared for each kidney.

RESULTS

The risks of missing DMSA scarring varied between 0.4% (school age children with solitary lower tract UTI) and 11.1% (infants with recurrent upper tract UTI).

CONCLUSIONS

UTI clinical features are important in assessing the need for DMSA imaging. Current UK imaging guidelines are endorsed, although preschool children with solitary lower tract UTI remain a controversial group and more attention needs to focused on children with recurrent UTI.

Voiding cystourethrograms and urinary tract infections: how long to wait?

OBJECTIVES

Many authorities recommend an interval of at least 3 to 6 weeks after a urinary tract infection (UTI) before performing a voiding cystourethrogram (VCUG). However, such an interval may reduce the likelihood of completing the procedure. This study was performed to investigate whether the length of the interval between a UTI and the performance of the VCUG influences the presence or severity of reflux, and whether it influences the likelihood of actually having the study performed.

DESIGN

We reviewed 352 admissions of children under 10 years old whose discharge diagnoses indicated UTIs. These admissions occurred over a 27-month period between October 1994 and December 1996 at the Children's Hospital of Austin, Texas. We identified 213 patients with confirmed UTIs and no other previously defined urinary tract pathology. These patients were divided into 2 groups according to whether they had a VCUG scheduled to be performed either within 1 week after the diagnosis of a UTI (the early group), or later than 1 week after the diagnosis (the late group). We compared the presence and severity of reflux in the 2 groups as well as the proportion of scheduled VCUGs that were actually performed.

RESULTS

Reflux was present in 19% of the patients studied within 1 week after UTI (95% confidence interval [CI]: 12.9-26.4) and in 18% of those studied after 1 week (95% CI: 6. 7-34.5). This difference was not statistically significant (chi(2) =. 034; DF = 1). However there was a substantial difference between the 2 groups with regard to the number of scheduled VCUGs actually performed. Whereas 100% of the scheduled VCUGs in the early group were performed, only 48% (95% CI: 35.9-60.1) of those scheduled in the late group were performed. This difference is statistically significant (chi(2) = 89.6; DF = 1).

CONCLUSIONS

In the hospitalized children who underwent VCUGs within a week after diagnosis of UTI, the presence of reflux is not significantly different from those studied later. Furthermore, late scheduling of VCUGs resulted in failure to perform the procedure in more than half of the patients. Some of the patients who were not evaluated would be expected to have vesicoureteral reflux and thus be at risk for chronic renal disease. Therefore, the traditional recommendation to perform the VCUG at 3 to 6 weeks after the diagnosis of UTI should be reconsidered, especially for hospitalized children.

Tc-99m DMSA renal scan in first-time versus recurrent urinary tract infection-yield and patterns of abnormalities

PURPOSE

To determine the yield and patterns of abnormalities noted by Tc-99m DMSA renal imaging in cases of first-time versus recurrent urinary tract infections (UTIs) in children.

MATERIALS AND METHODS

We reviewed 101 Tc-99m DMSA studies performed for 52 first-time and 49 recurrent UTIs in 99 children during a period of 1 year. The average age of the patients was 4.4 years, and the female:male ratio was 7:1. Static images of the kidneys were acquired 2 hours after injection of Tc-99m DMSA in anterior, posterior, and right and left posterior oblique views. SPECT was performed in 9% of the cases. The studies were scored as normal or abnormal.

RESULTS

The yield of abnormal scans in first-time UTIs was 22 (42%) and in recurrent UTI 27 (55%). Three categories of abnormalities were noted: 1) renal cortical defects (55% of the abnormal scans in first-time UTIs and 59% of the abnormal scans in recurrent UTIs; P = 0.40); 2) dilated pelvicalyceal system (27% of the abnormal studies in first-time UTIs and 63% of the abnormal studies in recurrent UTIs; P < 0.01); and 3) renal swelling showing disproportionate function with size (41% of the abnormal scans in first-time UTIs and 22% of the abnormal scans in recurrent UTIs; P = 0.21).

CONCLUSIONS

The high yield of renal abnormalities by Tc-99m DMSA scanning emphasizes the importance of testing all cases of UTI, including patients with a first-time infection. Documentation of the pattern of abnormalities may help in planning for subsequent management of UTIs in these patients.

Serum immunoglobulin response and protection from homologous challenge by Proteus mirabilis in a mouse model of ascending urinary tract infection

We tested the hypothesis that experimental Proteus mirabilis urinary tract infection in mice would protect against homologous bladder rechallenge. Despite production of serum immunoglobulin G (IgG) and IgM (median titers of 1:320 and 1:80, respectively), vaccinated (infected and antibiotic-cured) mice did not show a decrease in mortality upon rechallenge; the survivors experienced only modest protection from infection (mean log(10) number of CFU of P. mirabilis Nal(r) HI4320 per milliliter or gram in vaccinated mice versus sham-vaccinated mice: urine, 100-fold less [3.5 versus 5.5; P = 0.13]; bladder, 100-fold less [3.1 versus 5.1; P = 0.066]; kidneys, 40-fold less [2.7 versus 4.3; P = 0.016]). Western blots using protein from the wild-type strain and isogenic mutants demonstrated antibody responses to MR/P and PMF fimbriae and flagella. There was no correlation between serum IgG or IgM levels and protection from mortality or infection. There was a trend toward elevated serum IgA titers and protection from subsequent challenge (P >/= 0.09), although only a few mice developed significant serum IgA levels. We conclude that prior infection with P. mirabilis does not protect significantly against homologous challenge.

Vesico-ureteric reflux and other risk factors for renal damage: identification of high- and low-risk children

This article reviews the literature with respect to various risk factors for permanent renal damage in children with urinary tract infection. Vesico-ureteric reflux is an important risk factor, but renal damage can occur in the absence of reflux. Renal damage does not always occur in the presence of gross reflux. Renal scars always develop at the same site as a previous infection in the kidney. Recurrent pyelonephritis and delay in therapy increase the likelihood of renal damage, although it is not known how long a delay is dangerous to the human kidney. Recent studies using 99mtechnetium-dimercaptosuccinic acid (DMSA) scintigraphy have not confirmed the findings of previous studies showing that children below 1 y of age are more vulnerable to renal damage. It is more likely that all children run the risk of renal scarring in cases of acute pyelonephritis. The role of bladder pressure is still not entirely understood. Therefore more studies are needed in order to determine the relationship between high voiding pressures in some, otherwise healthy, children with urinary tract infection and renal scarring. The importance of bacterial virulence in the development of renal scarring is unclear. DMSA scintigraphy and voiding cystourethrography are the most reliable tools for identifying children at risk of renal scarring. As a single method DMSA scintigraphy appears to be better than voiding cystourethrography.

The use of urinary dipstix in children with high-risk renal tracts

Urinary tract infection (UTI) is one of the most common acute illnesses found in infants and children and up to 5% of girls and 1% of boys will experience one or more episodes. Bables and children with abnormal renal tracts are at risk of developing scarred kidneys as a result of recurrent UTI, leading to an increased risk of hypertension and end-stage renal failure in later life. It seems logical, therefore, to place high priority on the early detection, prompt treatment and adequate follow up of children with high-risk renal tracts. This article describes the use of home urine testing for the early detection of UTI in children with high-risk renal tracts.

Consensus on renal cortical scintigraphy in children with urinary tract infection. Scientific Committee of Radionuclides in Nephrourology

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.

Acute childhood pyelonephritis: predictive value of positive sonographic findings in regard to later parenchymal scarring

RATIONALE AND OBJECTIVES

The authors evaluated the importance of positive sonographic findings in acute childhood pyelonephritis.

MATERIALS AND METHODS

A total of 290 children (91 boys, 199 girls, aged 4 days to 15 years [median, 394 days]) with clinically suspected acute pyelonephritis underwent initial renal gray-scale ultrasound (US) and dimercaptosuccinate scintigraphic examination within 3 days of onset. A total of 173 patients underwent color or energy US examination. One hundred fifteen children with normal scintigraphic or pathologic findings (other than acute pyelonephritis) were excluded from further study; 170 patients with abnormal scintigraphic findings underwent follow-up scintigraphic scanning 60-90 days later.

RESULTS

When pathologic structures other than acute pyelonephritis were not considered, the diagnostic value of gray-scale US was poor, with a sensitivity of 45.5%, a specificity of 86.6%, a positive predictive value of 88.8%, and a negative predictive value of only 40.6%. In regard to future renal scarring, gray-scale US had a positive predictive value of 67.7%, a negative predictive value of 40%, and a likelihood ratio of 1.16. Abnormal Doppler findings helped predict future scarring with a positive predictive value of 85.7%, a negative predictive value of 37.2%, a very low sensitivity of 26.9%, a high specificity of 90.6%, and a likelihood ratio of 2.87.

CONCLUSION

Positive US Doppler findings in children with clinically suspected acute pyelonephritis indicate the need for immediate treatment. A positive initial gray-scale US examination does not predict future renal scarring, but a positive Doppler examination indicates a high probability of scarring. Negative gray-scale or Doppler US does not exclude a diagnosis of acute pyelonephritis and it cannot predict an absence of future scarring.

Kidney swelling. Findings on DMSA scintigraphy

OBJECTIVE

To develop criteria identifying swollen kidneys on dimercaptosuccinic acid (DMSA) renal scintigraphy in acute pyelonephritis with regard to the DMSA distribution pattern, kidney functional size, and radioactive uptake.

SUBJECTS AND METHODS

Thirty-eight children aged 15 days to 7 years with known pyelonephritis were examined with DMSA renal scintigraphy. All children were observed 2 or 3 times. In total, 94 scintigrams were evaluated. Qualitative and quantitative criteria for swelling were defined.

RESULTS

Thirty-one observed kidneys satisfied the criteria of swelling. Quantitatively, kidney length and width/length were greater in swollen kidneys. Kidney uptake in percent of injected dose and kidney uptake/background were lower in swollen kidneys. Qualitatively, focal radioactive uptake defects known from a previous examination were sometimes obscured by swelling, and reappeared at follow-up. In 5 children with signs of swelling on repeat imaging, scintigraphy reinfection at the time of swelling was verified.

CONCLUSIONS

Swollen kidneys may be the only sign of acute pyelonephritis on DMSA scintigraphy and swelling may obscure focal radioactive uptake defects. Measurement of kidney size and radioactive uptake can help identify swollen kidneys at DMSA scintigraphy and disclose acute pyelonephritis in the absence of overt clinical symptoms.

Distress and radiological investigations of the urinary tract in children

The distress associated with radiological investigations may be related to the information and style of parental explanation given to the child and the parents own coping style. In a questionnaire survey we assessed distress in relation to investigations of the urinary tract using the Groningen Distress Rating Scale and the Utrecht Coping List. We found the micturating cystourethrogram (MCUG) to be significantly more distressing than radionuclide investigations. MCUG distress was adversely correlated with passive and palliative parental coping styles. Results suggested that cognitive coping styles modelled by the parents ameliorated distress on dimercaptosuccinic acid scintigraphy.

CONCLUSION

The high level of MCUG associated distress and presence of traumatised children in the MCUG sample, along with the potential for parental contribution to distress reduction, suggests that both children and parents would benefit from more active preparation programmes prior to MCUG testing.

Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 1: Reflux

In 3646 children with at least one confirmed urinary tract infection the prevalence of vesicoureteric reflux at presentation was correlated with progressive renal damage during follow up of not less than two and up to 16 years. Reflux was not demonstrated either at presentation or at any subsequent time in almost one half of the children who suffered progressive renal damage and was not a risk factor for progressive renal damage in boys under 1 year. It was an important risk factor in boys over 1 year and in girls of any age. The risk of progressive renal damage in children in whom micturating cystourethrography (MCU) did not reveal vesicoureteric reflux was substantially greater than in those who indirect isotope voiding study (IVS) did not show reflux. The risk of deterioration for those in whom reflux was demonstrated was similar for both techniques. This discrepancy indicates an appreciably higher false negative rate for the MCU than the IVS. Dilatation of the renal pelvis detected by ultrasound was associated with a significantly increased risk of progressive damage only when associated with reflux, but most children with progressive damage did not have a dilated collecting system at presentation.