Diagnostic accuracy of doppler twinkling artifact in diagnosing smaller than 5 mm urolithiasis

Abstract

Background: The Doppler twinkling effect has also become a promising adjunctive method to improve the ultrasound image of small urinary stones. The aim of the current research was to determine the diagnostic accuracy of the Doppler twinkling artifact in detecting urolithiasis with a diameter less than 5mm using non-contrast computed tomography of the kidneys, ureters, and bladder (CT-KUB) as the reference standard. Methods: This cross-sectional validation study carried out at the Department of Radiology, Indus hospital and health network, Karachi, between the months of August 2025 and March 2026. The sample comprised 134 patients aged between 20 and 80 years old and whose chief complaint was acute flank pain, which was followed by sequential grayscale and color Doppler ultrasonography, then non-contrast CT-KUB. The twinkling artifact in the Doppler imaging was noted and its diagnostic capability evaluated. All the essential diagnostic accuracy parameters were evaluated and stratified analysis was done on the basis of age, gender and duration of onset of symptoms. Results: Study was male dominant with 62.7% of male population and mean age of the total study population was 50.4±18.46 years. Urolithiasis was positive in 38.1% of enrolled subjects on non-contrast CT. Doppler twinkling artifact demonstrated a sensitivity of 86.3%, specificity of 92.8%, PPV of 88.0%, NPV of 91.7%, and overall diagnostic accuracy of 90.3%. The accuracy of the diagnosis had been found to be consistent across gender, age groups, and symptom duration with the overall accuracy ranging between 87.5% and 93.0%. Conclusion: The Doppler twinkling artifact is a noninvasive, radiation-free, reliable imaging adjunct, which has high diagnostic accuracy in detecting urolithiasis less than 5mm. Its systemic integration with ultrasound assessments would make it less reliant on computed tomography particularly in resource-limited contexts.