Which of the following are radiolucent renal stones?

Ans. a (Uric acid stones). (Ref. B & L, Surgery, 25th/l 296)Renal calculi Urinary calculiaccount for what % of urinary calculi1.Calcium oxalate, calcium phosphate, or a mixture of the two75%2.Phosphate stones .15%3.Uric acid stones5-10%-It has been estimated that most (85-90%) of all renal stones are radioopaque. Calcium phosphate stones have the greatest density, followed by calcium oxalate and magnesium ammonium phosphate. Cystine calculi are only mildly radiodense. Uric acid calculi are radiolucent.0-Helical CT has been shown to be more accurate than KUB X-ray, IVU, and US for diagnosis of ureteral calculi. Because of its safety, speed, cost-effectiveness, accuracy, and ability to assess other potential causes of flank pain, nonenhanced helical CT should replace IVU. as the most effective studv used for the diagnosis of ureteral calculus disease. Furthermore, essentially all stones, including uric acid stones, appear dense on CT.e