Reappraisal of the effectiveness of ^99mTc‐dimercaptosuccinic acid scans for selective voiding cystourethrography in children with a first febrile urinary tract infection

Abstract

Recent studies have yielded conflicting results regarding the ability of technetium-99m dimercaptosuccinic acid ((99m)Tc-DMSA) renal scans for identifying high-grade vesicoureteral reflux (VUR) in children with a first febrile urinary tract infection (UTI). This study aimed to reevaluate the effectiveness of (99m)Tc-DMSA renal scans for selective voiding cystourethrography (VCUG) in children with a first febrile UTI. The medical records of children aged ≤ 5 years who were admitted with a first febrile UTI were retrospectively reviewed. Ultrasonography (US) and DMSA renal scans were performed within 3-5 days after admission, and VCUG was performed 7-10 days after antibiotics treatment. A total of 653 children were enrolled for analysis, including 579 patients aged < 2 years (Group A) and 74 patients aged 2-5 years (Group B). In Group A, DMSA scans were abnormal for 346 patients (59.8%), and normal for 233 patients (40.2%). High-grade VUR was present in 99 of 346 patients (28.9%) with abnormal DMSA scans, but present in only 16 of 233 patients (6.9%) with normal DMSA scans (p < 0.001). Regarding the prediction of high-grade VUR, the sensitivity and negative predictive value (NPV) for the DMSA scans were 86.1% and 93.1%, respectively. In Group B, DMSA scans were abnormal for 36 patients (48.6%), and normal for 38 patients (51.4%). High-grade VUR was present in 12 of 36 patients (33.3%) with abnormal DMSA scans, whereas none of the 38 patients with normal DMSA scans had high-grade VUR (p < 0.001). The sensitivity and NPV of the DMSA scans were both 100%. Using the selective VCUG strategy, approximately 40% of Group A patients and 50% of Group B patients could be spared an unnecessary VCUG, respectively. Our study results suggest that (99m)Tc-DMSA renal scans are effective in identifying children with a first febrile UTI for selective VCUG.

Ureter Visualization on Tc-99m DMSA Scintigraphy in Pediatric Patients

“…However, in that study and other previous studies the decision was based on presence of scar in renal parenchyma. Several other studies have pointed out the same finding and have concluded that cystourethrography is indicated in only patients with DMSA abnormalities [2]. This methodology has high sensitivity and negative predictive value in the detection of high grade VUR (86% and 93% respectively) [2,3].…”

“…Several other studies have pointed out the same finding and have concluded that cystourethrography is indicated in only patients with DMSA abnormalities [2]. This methodology has high sensitivity and negative predictive value in the detection of high grade VUR (86% and 93% respectively) [2,3]. The Visualization of the dilated collecting system in DMSA scintigraphy has never been analyzed previously.…”

“…Recent studies have indicated another potential benefit of DMSA scan to pick patients who need further imaging by voiding for diagnosis of VUR [2,3]. None of the patients with normal DMSA scintigraphy had high grade VUR according to these reports.…”