Comparative study of ultrasound and computerized tomography for nephrolithiasis detection

Abstract

Background: There is a lack of consensus about whether the initial imaging method for patients with suspected nephrolithiasis should be computed tomography (CT) or ultrasonography. Material and Methods: A total of 130 patients' USG and CTU were compared for the presence of calculi. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of USG were calculated with CTU as the gold standard. Results: From the 150 sets of data collected, 45 calculi were detected on both USG and CTU. The sensitivity and specificity of renal calculi detection on USG were 53% and 85% respectively. The mean size of the renal calculus detected on USG was 6.8 mm ± 3.8 mm and the mean size of the renal calculus not visualized on USG but detected on CTU was 3.5 mm ± 2.7 mm. The sensitivity and specificity of ureteric calculi detection on USG were 12% and 97% respectively. The sensitivity and specificity of urinary bladder calculi detection on USG were 20% and 100% respectively. Conclusion: This study showed that the accuracy of US in detecting renal, ureteric and urinary bladder calculi were 68%, 80% And 99% Respectively.

Imaging in stone diagnosis and surgical planning

“…US can be used to directly visualize a stone or shadow, albeit at a lower accuracy than CT. In comparison to CT diagnosis, recent comparisons have reported US sensitivity (52 -75%) and specificity (85-96%) for renal calculi, as well as sensitivity (12%) and specificity (93-97%) for ureteral calculi [50,51]. This may be insufficient for patient care, particularly in patients with suspected ureterolithiasis.…”