Congress:
ECR25
Poster Number:
C-18055
Type:
Poster: EPOS Radiologist (educational)
DOI:
10.26044/ecr2025/C-18055
Authorblock:
M. A. Rodrigues, L. Cymbron Barros, M. Silva, C. Pinto, J. P. Vieira, A. L. Faria Pinto, M. Chaves, I. C. S. P. Basto; São Miguel - Açores/PT
Disclosures:
Maria Aguiar Rodrigues:
Nothing to disclose
Leonor Cymbron Barros:
Nothing to disclose
Marta Silva:
Nothing to disclose
Claudia Pinto:
Nothing to disclose
João Pedro Vieira:
Nothing to disclose
Ana Luisa Faria Pinto:
Nothing to disclose
Mariana Chaves:
Nothing to disclose
Isabel Cristina Silva Paiva Basto:
Nothing to disclose
Keywords:
Kidney, Fluoroscopy, Ultrasound, Cystography / Uretrography, Congenital, Infection
- Diagnostic Imaging Approaches
- Ultrasound (US): US is the first-line imaging modality due to its non-invasive nature, cost-effectiveness, and absence of ionizing radiation. It is recommended for febrile UTI cases, particularly in children under two years old or those with recurrent infections [4]. Ultrasound can detect hydronephrosis, congenital anomalies, renal abscesses, and ureteropelvic junction obstructions. However, it has limitations in detecting vesicoureteral reflux (VUR), necessitating further evaluation with other imaging modalities when clinically indicated.
Fig 1: Figure 1. A. Longitudinal ultrasound of the right kidney demonstrating loss of corticomedullary differentiation and generalized reduction in parenchymal thickness. B. Transverse section of the same kidney showing marked pelvicalyceal dilation, with the renal pelvis measuring 21 mm in anteroposterior diameter. References: Radiology Department, Hospital do Divino Espírito Santo - Ponta Delgada/PT.
Fig 2: Figure 2. A. Longitudinal ultrasound of the right kidney with preserved corticomedullary differentiation and parenchymal index. However, early ectasia of the excretory cavities is noted. B. Transverse section of the same kidney showing the renal pelvis in anteroposterior section, measuring 7 mm. References: Radiology Department, Hospital do Divino Espírito Santo - Ponta Delgada/PT. - Voiding Cystourethrography (VCUG): VCUG is considered the gold standard for diagnosing VUR. It involves catheterization of the bladder, filling it with contrast, and using fluoroscopy to observe for urinary reflux into the ureters. Despite its diagnostic value, VCUG is invasive and exposes children to radiation. As a result, the ESPU and NICE guidelines recommend limiting its use to high-risk cases, such as those with recurrent febrile UTIs or abnormal ultrasound findings [3]. Alternative approaches, such as contrast-enhanced ultrasound (CEUS), are being explored to reduce the need for VCUG.
Fig 3: Figure 3. Vesicoureteral Reflux Grade IV on Cystography – During the pre-voiding phase, contrast reflux was observed into the right excretory system, extending up to the intrarenal level, with slight tortuosity of the ureteral pathway. During the voiding phase, the reflux worsened, with straightening of the intrarenal papillary impressions, consistent with Grade IV reflux. References: Radiology Department, Hospital do Divino Espírito Santo - Ponta Delgada/PT.
Fig 4: Figure 4. Vesicoureteral Reflux Grade V on Cystography – During the filling phase, passive Grade V vesicoureteral reflux (VUR) was observed on the left side, with opacification of the ureter, renal pelvis, and calyces. This caused marked ureteral dilation and tortuosity, as well as distension and bulging of the excretory system. References: Radiology Department, Hospital do Divino Espírito Santo - Ponta Delgada/PT. - Dimercaptosuccinic Acid (DMSA) Scintigraphy: DMSA is used to evaluate renal parenchymal damage and detect scarring following febrile UTIs. It involves the injection of a radiopharmaceutical agent that accumulates in the renal cortex, allowing for detailed assessment of kidney function and structure. DMSA is particularly valuable in identifying pyelonephritis and long-term scarring but is less frequently performed in routine practice due to high costs, limited availability, and its minimal impact on changing clinical management [5]. Current recommendations suggest reserving DMSA scans for cases in which renal scarring is suspected or for research settings focusing on the long-term consequences of pediatric UTIs.
- Contrast-Enhanced Ultrasound (CEUS): CEUS uses microbubble contrast agents to visualize urinary reflux without ionizing radiation. This technique has shown comparable sensitivity to VCUG in detecting VUR. However, variability in technique and limited access to contrast agents have slowed its widespread adoption [6]. Ongoing research aims to establish standardized protocols for its use in pediatric UTI follow-up care.
- Ultrasound (US): US is the first-line imaging modality due to its non-invasive nature, cost-effectiveness, and absence of ionizing radiation. It is recommended for febrile UTI cases, particularly in children under two years old or those with recurrent infections [4]. Ultrasound can detect hydronephrosis, congenital anomalies, renal abscesses, and ureteropelvic junction obstructions. However, it has limitations in detecting vesicoureteral reflux (VUR), necessitating further evaluation with other imaging modalities when clinically indicated.
- Guidelines for Imaging in Pediatric UTIs
- AAP Recommendations suggest that routine imaging is unnecessary after a first uncomplicated febrile UTI. Ultrasound is recommended following a second febrile UTI or in infants under two years old with severe symptoms. VCUG is reserved for cases with abnormal ultrasound findings or recurrent febrile UTIs to assess VUR. The emphasis is on a targeted approach, reducing unnecessary testing while ensuring that children at risk of complications receive appropriate follow-up care [4].
- NICE Guidelines promote a risk-based approach, avoiding unnecessary invasive imaging. They recommend ultrasound for infants under six months with a febrile UTI or children with recurrent or atypical infections. VCUG should be limited to cases where ultrasound suggests severe renal abnormalities or in patients with a history of recurrent UTIs. The guidelines also highlight the need for parental education on recognizing UTI symptoms and adhering to treatment protocols to prevent recurrence [2].
- ESPU Guidelines (2021) emphasize stepwise imaging, prioritizing ultrasound as the initial modality. They advocate for limiting VCUG to select high-risk patients, reducing overall radiation exposure, and integrating non-invasive imaging techniques with clinical follow-up to guide decision-making. The focus is on balancing diagnostic accuracy with minimizing patient discomfort and healthcare costs [3].
Table 1: Table 1. Overview of current clinical guidelines.
- Sustainable Practices and Emerging Trends
- Reducing Overuse of Imaging is a key focus, as studies suggest that routine imaging does not significantly alter management or outcomes in many cases. A shift toward conservative management, including close clinical monitoring and targeted imaging, is increasingly adopted in pediatric nephrology and urology. Sustainable practices emphasize individualized care pathways, reserving imaging for high-risk groups while using clinical markers such as fever duration, inflammatory markers, and response to antibiotics to guide decision-making [5].
- The Role of Artificial Intelligence (AI) in Pediatric UTI Imaging is growing, with AI-based analysis of ultrasound and other imaging modalities showing promise in improving diagnostic accuracy. Machine learning algorithms can assist in identifying structural anomalies and predicting which patients may develop renal complications. AI-driven automation may reduce the need for invasive procedures by enhancing the precision of risk assessment models. AI-assisted ultrasound interpretation has also been explored as a method to improve standardization in detecting hydronephrosis and renal parenchymal changes [7].
- Long-Term Outcomes and Implications for Care indicate that children with low-grade VUR often resolve spontaneously without significant renal damage. The role of imaging should be to stratify patients based on risk, avoiding overdiagnosis and overtreatment. Studies highlight that a conservative approach to VUR management, including close observation and antibiotic prophylaxis when necessary, is often as effective as surgical intervention for many cases. Optimized imaging strategies should balance the need for early detection of renal abnormalities while avoiding excessive interventions [8].