Nephrolithiasis, or kidney stone disease, refers to the formation and passage of stones within the urinary tract. Stones form when certain substances in the urine become concentrated and crystallize, with calcium oxalate being the most common composition. On ultrasound, nephrolithiasis is suggested by the presence of echogenic foci with posterior acoustic shadowing within the renal collecting system or ureter, accompanied by the indirect sign of hydronephrosis. While non-contrast CT is the gold standard for diagnosis of nephrolithiasis, ultrasound is commonly used for initial evaluation, particularly in pregnant women and children to avoid radiation. Renal Doppler assessment of ureteral jets can provide additional information about the degree of ureteral obstruction.
Sonography Term