Computed Tomography Findings in Nephrolithiasis

CT scan sensitivity of 94-97% and a specificity of %, helical CT is the most sensitive radiologic examination for the detection, localization, and characterization of urinary calcifications faster and no contrast agent is needed in most patients easily differentiates between non-opaque stones and blood clots or tumors (compared with IVU, which may depict only a filling defect)

CT scan is better than US or IVU in detecting other causes of abdominal pain Rarely, pure matrix stones may demonstrate soft-tissue opacity on CT scans, and indinavir stones appear lucent all other stones appear opaque on CT scans

CT may depict the following: Stones in the ureter Enlarged kidneys Hydronephrosis (83% sensitive, 94% specific) Perinephric fluid (82% sensitive, 93% specific) Ureteral dilatation (90% sensitive, 93% specific) Soft-tissue rim sign (good positive predictive value with a positive odds ratio of 31:

Computed Tomography Computed tomography without contrast is considered the gold-standard diagnostic test for the detection of kidney stones. Findings include renal morphology and ureteral stone localization

Axial Non-enhancded CT Sonogram image shows a hyperdense calculus in the right proximal ureter.

Coronal Non- enhanced CT Sonogram image shows a hyperdense calculus at the right proximal ureter. This would indicate a stone lodged at the ureteropelvic junction.