Incidence of renal scarring on technetium-99 m dimercaptosuccinic acid renal scintigraphy after acute pyelonephritis, acute focal bacterial nephritis, and renal abscess

Complete Remission of Renal Scarring in Follow-Up DMSA Renal Scintigraphy After Urinary Tract Infection

Our study aimed to investigate the association between the characteristics of patients/images and complete remission of renal scarring shown in the first chronic phase Technetium-99m dimercaptosuccinic acid (DMSA) renal scintigraphy images in children with urinary tract infection (UTI). Fifty children, who underwent the chronic phase of DMSA scintigraphy more than twice following UTI diagnosis and had renal scarring in the first chronic phase DMSA renal scintigraphy, were enrolled. They were classified into 2 groups: with and without complete remission of renal scarring on the second chronic phase DMSA renal scintigraphy. Renal scarring was classified into 3 grades based on severity per the image findings. Seven cases had complete remission from renal scarring. There were significant differences in age and severity. Renal scarring might be completely reversed in young children without severe findings on DMSA renal scintigraphy. Additional chronic phase examination may aid in follow-up completion and patients' peace of mind.

Vesico-ureteral reflux diagnosis after initial kidney abscess: Results from a Paediatric Tertiary Hospital

AIMS

Guidelines regarding voiding cystourethrogram (VCUG) indications following a paediatric kidney abscess are lacking. This study evaluates vesicoureteral reflux (VUR) prevalence and outcome after a first kidney abscess.

METHODS

This retrospective study included all children presenting to a tertiary paediatric reference centre with de-novo kidney abscesses from 2011 to 2022, diagnosed through imaging (ultrasonography or computed tomography). VCUG's clinical utility was assessed by exploring outcomes related to interventions.

RESULTS

Among the 17 patients (median age 9 months, IQR; 6 months-6 years), VCUG identified VUR in 7 (41%; 95% CI: 18-65%), including two with grade IV-V. Median abscess size was 19 mm (IQR; 14-27). 7/8 (88%) children with DMSA scan presented scars, including 4 with hypofunctioning (20%-44%), and one with a non-functioning kidney. Scarring on the DMSA scan was similar regardless of identified VUR. Six children had subsequent pyelonephritis. Three of the remaining 11 had grade I-III and two IV-V VUR. Surgery was required in four children overall: three for recurrent pyelonephritis and one for high-grade VUR and scars.

CONCLUSION

Among initial kidney abscess cases, 41% had VUR, similar to children experiencing their first uncomplicated pyelonephritis. VCUG results guided antibiotic prophylaxis but not surgical decisions. We suggest considering VCUG following recurrent pyelonephritis/kidney abscess and/or kidney scarring.

Computer-assisted decision support for the usage of preventive antibacterial therapy in children with febrile pyelonephritis: A preliminary study

Urinary tract infection (UTI) is one of the most common infectious diseases among children, but there is controversy regarding the use of preventive antibiotics for children first diagnosed with febrile pyelonephritis. To the best of our knowledge, no studies have addressed this issue by the deep learning technology. Therefore, in the current study, we conducted a study using Tc 99 m - DMSA renal static imaging data to investigate the need for preventive antibiotics on children first diagnosed with febrile pyelonephritis under 2 years old. The self-collected dataset comprised 64 children who did not require preventive antibiotic treatments and 112 children who did. Using several classic deep learning models, we verified that it is feasible to screen whether the first diagnosed children with febrile pyelonephritis require preventive antibacterial therapy, achieving a graded diagnosis. With the AlexNet model, we obtained accuracy of 84.05%, sensitivity of 81.71% and specificity of 86.70%, respectively. The experimental results indicate that deep learning technology could provide a new avenue to implement computer-assisted decision support for the diagnosis of the febrile pyelonephritis.

Utility of MRI in diagnosis and treatment of acute focal bacterial nephritis with abscess formation in a paediatric patient

Contrast-enhanced CT is the gold standard for the diagnosis of acute focal bacterial nephritis (AFBN). However, owing to radiation exposure and the possibility of contrast agent-induced side effects, contrast-enhanced CT is not always recommended for children. A paediatric patient presenting with a 1-week history of fever was admitted to our hospital. After a urine culture detected Escherichia coli, antimicrobials were administered; however, the fever had not resolved by the third day of hospitalisation. Renal diffusion-weighted MRI was performed and showed multiple wedge-shaped areas of high signal intensity in the right kidney. Additionally, the same site showed an area of low signal intensity in the apparent diffusion coefficient, and a diagnosis of AFBN with abscess was made. A chronic-phase technetium-99m-labelled dimercaptosuccinic acid renal scintigraphy was performed, but there was no renal scarring. MRI may be a more suitable tool for diagnosing AFBN given no radiation exposure.