Prediction of vesicoureteral reflux in children with febrile urinary tract infection using relative uptake and cortical defect in DMSA scan

Improved grading method of 99m Tc-dimercaptosuccinic acid static renal imaging helps predict the prognosis of urinary tract infection in children

OBJECTIVE

This study aimed to refine the 99m Tc-dimercaptosuccinic acid (Tc-99m DMSA) renal static imaging (DMSA) rating method and evaluate its prognostic value in children with urinary tract infections (UTIs) associated with vesicoureteral reflux (VUR).

METHODS

Retrospective analysis was conducted on DMSA data (DMSA1 at the initial visit and DMSA2 at follow-up; imaging interval ≥ 6 months) and clinical data from 117 children. Each kidney was divided into three regions: upper, middle, and lower. Lesions were graded in a blinded manner based on the distribution of the imaging agent and whether the defect area exceeded 50% of the region. Lesion grades were classified as 0 (normal) to 5 (complete defect). DMSA2 ratings were categorized as complete recovery, improvement, similar, or deterioration, and clinical factors influencing each group were analyzed.

RESULTS

A total of 160 diseased kidneys were identified in 117 children. The DMSA1 and DMSA2 image ratings were highly consistent (kappa coefficients: 0.806, 0.839, 0.813, 0.820 for left and right kidneys, respectively). A statistically significant difference in image ratings was observed between DMSA1 and DMSA2 when DMSA1 rating was ≥3b. Changes in DMSA2 ratings were associated only with the initial DMSA1 rating and the presence of breakthrough urinary sensation at follow-up.

CONCLUSION

Image changes were related solely to breakthrough urinary sensation. When the initial DMSA lesion grade exceeds 3b, improvement in the lesion is unlikely, regardless of subsequent breakthrough urinary sensation. The modified DMSA rating method is effective and can predict prognosis in children with UTIs.

How the 99mTc-DMSA scintigraphy findings are reflected in the adopted treatment of primary vesicoureteral reflux: One centre experience

BACKGROUND

Renal changes may have long-term sequalae and prevention is a main goal of management of primary vesicoureteral reflux (VUR).

AIM

This study aims to reveal how much ^99mTc-DMSA scintigraphy findings are reflected in the adopted surgical or non-surgical treatment in children with diagnosed primary VUR and to give the clinicians information regarding their final therapeutic decision.

PATIENTS AND METHODS

A total 207 children with primary VUR who underwent non-acute ^99mTc-DMSA scan were retrospectively evaluated. The presence of renal changes, their grading, differential function asymmetry (<45%) and grade of VUR were compared with subsequent choice of therapy.

RESULTS

Altogether 92 (44%) children had asymmetric differential function, 122 (59%) showed presence of renal changes, 79 (38%) had high-grade VUR (IV-V). Patients with renal changes had lower differential function (41%vs.48%) and higher grade of VUR. The incidence of high-grade changes (G3+G4B) afflicting more than one third of the kidney was significantly different between grade I-II, III and IV-V VUR (9%, 27%, 48%, respectively). Renal changes were detected in 76% of surgically and 48% of non-surgically treated patients, high-grade ^99mTc-DMSA changes in 69% and 31%, respectively. In children with no scars/dysplasia (G0+G4A), non-surgical treatment prevailed in 77%. The independent predictors for surgical intervention were presence of renal changes and higher grade of VUR, but not functional asymmetry.

DISCUSSION

Over the last 20 years, there has been a shift toward more non-surgical management of VUR. The long-term outcome of this approach should be thoroughly studied. This is the first study analysing renal status in VUR patients using ^99mTc-DMSA scan and its grading regarding the adopted treatment. Renal changes in almost half of non-surgically treated children with VUR should be an indicator for earlier diagnosis and effective treatment of acute pyelonephritis and VUR. We recommend distinguishing grade III VUR, as a moderate-grade VUR, because it is linked to higher incidence of high-grade ^99mTc-DMSA changes (G3+G4B); our findings of 65% of grade III VURs treated non-surgically should be cautionary. Grade III VUR does not mean a low-risk condition and should alert the clinician to evaluate the extent of renal changes and unmask high-risk cases.

CONCLUSIONS

Our data strengthens the need to investigate the extent of renal changes in VUR patients regarding treatment decision. Performing ^99mTc-DMSA scan individualizes the treatment of VUR patients; its grading can distinguish grade III-VUR as a separate risk entity because it differs significantly in terms of incidence of high-grade renal changes and chosen therapy.

A nomogram for predicting upper urinary tract damage risk in children with neurogenic bladder

PURPOSE

To establish a predictive model for upper urinary tract damage (UUTD) in children with neurogenic bladder (NB) and verify its efficacy.

METHODS

A retrospective study was conducted that consisted of a training cohort with 167 NB patients and a validation cohort with 100 NB children. The clinical data of the two groups were compared first, and then univariate and multivariate logistic regression analyses were performed on the training cohort to identify predictors and develop the nomogram. The accuracy and clinical usefulness of the nomogram were verified by receiver operating characteristic (ROC) curve, calibration curve and decision curve analyses.

RESULTS

There were no significant differences in other parameters between the training and validation cohorts except for age (all P > 0.05). Recurrent urinary tract infection, bladder compliance, detrusor leak point pressure, overactive bladder and clean intermittent catheterization were identified as predictors and assembled into the nomogram. The nomogram showed good discrimination with the area under the ROC curve (AUC) in the training cohort (0.806, 95% CI: 0.737-0.874) and validation cohort (0.831, 95% CI: 0.753-0.0.909). The calibration curve showed that the nomograms were well calibrated, with no significant difference between the predicted and observed probabilities. Decision curve analysis indicated that the nomogram has good clinical applicability.

CONCLUSION

This study presents an effective nomogram incorporating five clinical characteristics that can be conveniently applied to assess NB children' risk of progressing to UUTD.

Urinary neutrophil gelatinase-associated lipocalin: a marker of urinary tract infection among febrile children

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a valuable biomarker of urinary tract infection (UTI) in children.

PURPOSE

This study aimed to compare the diagnostic accuracy of urinary NGAL (uNGAL) with those of serum C-reactive protein (CRP) and white blood cell (WBC) count for predicting UTI and acute pyelonephritis (APN) in febrile children.

METHODS

The medical charts of children undergoing uNGAL measurements between November 2017 and August 2019 were retrospectively reviewed. Patients with a suspected or diagnosed UTIs were included. The diagnostic accuracies of uNGAL, serum CRP, and WBC count for detecting UTI and APN were investigated. Independent predictors of UTI and APN were investigated using multivariable logistic regression analyses.

RESULTS

A total of 321 children were enrolled in this study. The uNGAL levels were higher in the UTI group (n=157) than in the non-UTI group (n=164) (P<0.05). Among children with a UTI, uNGAL levels were higher in the APN group (n=70) than, the non-APN group (n=87) (P<0.05). In the multivariate analysis, uNGAL was independently associated with UTI and APN (both P<0.05). Serum CRP and WBC count were not correlated with the presence of UTI and APN. Receiver operating curve analyses showed that the uNGAL level had the highest area under the curve (AUC) for predicting UTI and APN, respectively (AUC, uNGAL vs. CRP vs. WBC count, 0.860 vs. 0.608 vs. 0.669 for UTI; 0.780 vs. 0.680 vs. 0.639 for APN, all P<0.05, respectively). The predictive values and likelihood ratios of uNGAL were superior to those of serum CRP and WBC count for detecting UTI and APN at each cutoff level.

CONCLUSION

UNGAL may be more useful than serum CRP and WBC count for identifying and assessing UTI in febrile children.

Comparison of Tc-99m DMSA Renal Planar Scan and SPECT for Detection of Cortical Defects in Infants with Suspected Acute Pyelonephritis

OBJECTIVE

To compare the detection rate of Tc-99m dimercaptosuccinic acid (DMSA) renal single photon emission computerized tomography (SPECT) with that of planar scan for renal cortical defects in infants under one year of age with suspected acute pyelonephritis.

METHODS

Sixty infants under one year of age who exhibited fever and pyuria were prospectively included in this study. All infants underwent concurrent Tc-99m DMSA renal planar scan and SPECT. Detection rates for cortical defects and the numbers of cortical defects in both kidneys were compared between Tc-99m DMSA planar scan and SPECT. The cortical defects were classified as large and small; the rate of discordant results was compared between subgroups.

RESULTS

Negative findings by planar scan in 11 infants (11.3%) were modified to positive findings by SPECT. The detection rate of SPECT was significantly higher than that of planar scan (53.3% vs. 35.0%, p < 0.001). The numbers of cortical defects on SPECT were significantly higher than those on planar scan (0.85 ± 0.97 vs. 0.53 ± 0.83, p < 0.001). A significantly higher rate of discordant results between the planar scan and SPECT was observed for the small cortical defects compared to the large cortical defects (48.6% vs. 14.3%, p = 0.029).

CONCLUSIONS

Tc-99m DMSA renal SPECT showed a higher detection rate, compared with planar scan, for renal cortical defects in infants with suspected acute pyelonephritis. The study results suggest that, compared with planar scan, Tc-99m DMSA SPECT can detect small cortical defects with greater sensitivity.