<prompt> Not true about Struvite Stones is -better ka staghorn calculusthese are triple phosphate stonescommon in infected urineusually seen in acidic urine  <response>: Ans. is d ie Usually seen in acidic urine Struvite stone tends to grow in alkaline urine esp. when proteus organisms are present which split urea to ammonia. Types of Renal Calculus a Calcium oxalate calculus Most common - they have hard, small and jagged surface b Phosphate calculus - calcium phosphate but can be combined calculus ie Calcium amnomium magnesium phosphate also ka struvite stones. - smooth and diy white and soltitary. - seen in alkaline urine esp with proteus infection which split urea to ammonia. - this type of calculus may enlarge to fill all or most of the renal collecting system forming a staghorn calculus. c Uric acid and urate calculus - these are radioluscent - Form in acidic urine - Most responsive to lithotripsy d Cystein stones uncommon, seen in cystinuria - appear only in acidic urine - they are pink to yellow when first removed but they change colour to a greenish hue when exposed to air. extremely hard stones - are relatively resistant to fragmentation by ESWL e Xanthine calculi - are radioluscent - are secondary to a congenital deficiency of xanthine oxidase f Indinavir calculi Indinavir is a protease inhibitor used in AIDS patients. It results in calculi in --6 pt. who use. indinavir. Indinavir calculi are radioluscent. Rare Calculi Silicate stones - associated with the long term use of antacids containing silica Triamterene stones associated with antihypeensive medications containing trimterene are radioluscent 