Abstract
Introduction: In this study, we aimed to investigate the relationships between sonographic acoustic shadow
and density and, size of renal calculi with multidetector CT as the reference standard.
Materials and Methods: Fifty patients with suspected renal stone disease were prospectively examined.
Two staff radiologists performed real time sonography and were blinded to each other and two other
radiologists evaluated the CT images. For both imaging modality diagnosis of nephrolithiasis were made by
certain criteria. Cohen’s Kappa test was used to assess interobserver variability. Spearman’s rho analysis and
chi-square tests were used to assess the relationship between the density and size of the renal stones on noncontrast
CT and acoustic shadow on US examination.
Results: Eighty seven renal stones were identified in 36 (72%) of all patients on non-contrast CT. Of the
87 stones, the first radiologist diagnosed only 36 stones (41.3%), whereas the second radiologist diagnosed 41
(47.1) stones on US. Strong correlation was found between the density and size of the renal stones on noncontrast
CT images (p<0.001). Stones larger than 3 mm in diameter and denser than 300 HU on non-contrast
CT had acoustic shadows on US examination.
Conclusion: This study found a strong correlation between presence of acoustic shadow on US
examination and, size and density of renal stones on non-contrast CT examination.