Abstract
Objective: To determine the diagnostic accuracy of ultrasonography for detection of renal and ureteric calculi keeping computed tomography (CT) KUB as investigation of choice.
Methodology: This cross-sectional, validation study was performed at the department of radiology, CMH Gujranwala from June 2024 to January 2025. A total of 165 patients aged 18-70 year, underwent ultrasound (USG) and final reports were analyzed. All patients underwent CT KUB without contrast and the findings were also recorded keeping it as gold standard. A final report was recorded along with findings and analyzed. Demographic and clinicopathological data were entered in data collection proforma. Data Analysis was done by using SPSS v26.0. Diagnostic accuracy was calculated for USG and CT KUB in diagnosing renal or ureteric stones in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) with post stratification analysis keeping per operative findings as gold standard.
Results: In a total of 165 patients, the mean age was 37.56±9.21 years. USG demonstrated a sensitivity of 79%, specificity of 78%, and overall diagnostic accuracy of 79%, indicating moderate reliability. The area under the curve was 0.60. The PPV, and NPV were 92%, 55%, respectively.
Conclusion: Ultrasonography can be cost effective and safer investigation in initial evaluation of nephrolithiasis with CT KUB reserved for selected patients.

Key words: Computed tomography, nephrolithiasis, radiologist, ultrasonography, ureteric calculi.