Noncontrast helical CT is commonly used to evaluate for nephrolithiasis because it detects most stones, provides anatomic information, visualizes the entire urinary tract, may suggest stone composition, and potentially provides alternative diagnoses.
Ultrasonography is increasingly being used as an initial diagnostic study for nephrolithiasis due to availability, lack of radiation exposure, and low cost; it is also the preferred modality during pregnancy.
Hypercalciuria is the most common risk factor for calcium oxalate stones; management includes thiazide diuretics and a low sodium diet.
Treatment of urea-splitting Proteus or Klebsiella infections is the cornerstone of therapy for struvite stones, and surgical stone removal provides definitive therapy.
The main risk factor for uric acid stones is low urine pH; management may involve increased urine volume, urine alkalinization, and xanthine oxidase inhibitors.
For patients with kidney stones ≤10 mm in diameter, conservative management, including analgesia, hydration, and expulsive therapy, may be attempted.
Larger stones in the renal pelvis and proximal ureter can be treated with extracorporeal shock wave lithotripsy, whereas mid- and distal ureteral stones can be managed with ureteroscopy.