Interobserver variability for interpretation of DMSA scans in the RIVUR trial

Area of Science:

• Pediatric Nephrology
• Diagnostic Imaging
• Radiology

Background:

• Technetium-99m dimercaptosuccinic acid (DMSA) renal scans are crucial for diagnosing renal scarring in children.
• The Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial utilized DMSA scans to assess renal scarring in 607 children.

Purpose of the Study:

• To quantify interobserver variability in the interpretation of DMSA renal scans within the RIVUR trial.
• To compare local radiologist interpretations with reference radiologist assessments for DMSA scans.

Main Methods:

• DMSA scan reports from local radiologists (ALRs) were compared against adjudicated reports from two reference radiologists (RRs).
• Analyses included assessments of renal scarring and acute pyelonephritis.
• Unweighted kappa statistics were used to analyze agreement between ALRs and RRs.

Main Results:

• Reference radiologists identified 4% of kidneys with scarring, versus 7% by local radiologists.
• Local radiologists' scar grading was upgraded (24%) or downgraded (55%) by reference radiologists.
• For acute pyelonephritis, reference radiologists identified 3% of kidneys, versus 5% by local radiologists, with significant grading discrepancies.

Conclusions:

• Significant interobserver variability exists in reporting DMSA renal scans, exceeding that in prior studies.
• Lack of uniform reporting practices among local radiologists was a key limitation.
• Optimizing DMSA scan clinical value necessitates standardized interpretation guidelines.