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Imaging studies for first urinary tract infection in infants less than 6 months old: can they be more selective?
Niko Kei-chiu Tse1, Sandy Lai-kei Yuen, Man-chun Chiu
1Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Lai King Hill Road, Kwai Chung, Kowloon, Hong Kong SAR, China. tsekcniko@hotmail.com
Insights
The selective imaging approach for infants under 6 months with a first urinary tract infection (UTI) may miss significant cases of vesico-ureteral reflux (VUR) and kidney scarring, suggesting it
Area of Science:
- Pediatric Nephrology
- Diagnostic Imaging
- Infectious Diseases
Background:
- Urinary tract infections (UTIs) in infants under 6 months require careful diagnostic evaluation.
- National Institute for Health and Clinical Excellence (NICE) guidelines suggest a selective imaging approach for infants with UTI.
- The applicability of this selective approach in identifying significant renal pathology needs further assessment.
Purpose of the Study:
- To evaluate the effectiveness of the NICE 2007 selective imaging guidelines for infants under 6 months with their first UTI.
- To determine if the selective approach adequately identifies infants with vesico-ureteral reflux (VUR) and renal scarring.
- To compare outcomes between infants with typical and atypical UTI presentations based on risk features.
Main Methods:
- Retrospective study of 134 infants under 6 months with their first UTI.
- Infants underwent ultrasound (US), micturating cystourethrogram (MCUG), and dimercaptosuccinic acid (DMSA) scan.
- Patients were classified as typical or atypical based on predefined risk features from NICE guidelines.
Main Results:
- Atypical UTI cases showed a higher proportion of girls and significantly more abnormal MCUGs and VUR (grade III or higher).
- No significant differences in US or DMSA scan findings were observed between typical and atypical groups.
- Following the NICE selective imaging approach in the typical group would have missed 25 refluxing ureters and 22 scarred kidneys.
Conclusions:
- The NICE selective imaging approach for infants under 6 months with a first UTI may lead to underdiagnosis of significant VUR and renal scarring.
- This selective strategy may not be optimal for this age group.
- Further clarification on the best diagnostic imaging approach for infants with first UTI is warranted.
Abstract:
This retrospective study aimed to evaluate the applicability of the selective approach of imaging infants < 6 months old with urinary tract infection (UTI) according to the UTI guidelines of the National Institute for Health and Clinical Excellence (NICE) 2007. Infants < 6 months old with their first UTI from January 2001 to December 2006 having undergone an ultrasound examination of the urinary tract, a micturating cystourethrogram, and a late di-mercaptosuccinic acid (DMSA) scan, were included. Their condition was evaluated against a set of risk features according to the UTI guidelines. Those having any one of these were classified as atypical and those having none as typical. There were 134 infants reviewed, with a typical (98 infants) to atypical (36 infants) ratio of 2.7 to 1. Girls were found to be relatively more represented in the atypical group [male (M):female (F) = 1.3:1] than in the typical group (M:F = 4.4:1) (P < 0.004). There were significantly more infants with abnormal micturating voiding cystourethrograms (MCUGs) (P = 0.007), more refluxing ureters (P < 0.001) and more significant vesico-ureteral reflux (VUR) (>/= grade III) (P = 0.013) in the atypical group than in the typical group; while there was no significant difference in ultrasound (US) and DMSA scan findings between the two groups. In the atypical group there was no difference in imaging studies (and, thus, the results) between the conventional practice and the NICE UTI recommendation. In the typical group, if the recommendations of the guidelines had been followed (i.e. only those with abnormal US would have been further investigated), 25 refluxing ureters and 22 scarred kidneys would have been left undiagnosed. In conclusion, application of the suggested selective imaging approach would leave a significant number of VUR and renal scars undiagnosed, and it may not be an optimal practice for infants less than 6 months old with their first UTI. The best approach remains to be clarified.
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