Investigations and treatment of urinary stones

Investigations of Urinary stones

The investigations should include a mid-stream specimen of urine for culture and measurement of serum urea, electrolyte, creatinine and calcium levels.

Plain abdominal X-ray and excretion urography are still used widely for diagnosis, although unenhanced helical (spiral) CT is the best diagnostic test available.

Ureteric stones can be missed by ultrasound. Pure uric acid stones are radiolucent. Mixed infective stones in which organic matrix predominates are barely radiopaque. Calcium containing and cystine stones are radiopaque. Calculi overlying bone are easily missed. Staghorn calculi may be missed if the plain abdominal X-ray carried out before contrast injection during urography is not inspected. Uric acid stones may present as a filling defect after injection of contrast medium . Such stones are readily seen on CT scanning.


When excretion urography is carried out during the episode of pain; a normal urogram excludes the diagnosis of pain due to calculous disease. The urine of the patient should be passed through a sieve to trap any calculi for chemical analysis.

Treatment of urinary stones:

Adequate analgesia should be given. An NSAID, e.g. diclofenac 75 mg by i.v. infusion, compares favourably with pethidine and does not cause nausea. Stones less than 0.5 cm diameter usually pass spontaneously. Stones greater than 1 cm diameter usually require urological or radiological intervention. Extracorporeal shock wave lithotripsy (ESWL) will fragment most stones, which then pass spontaneously. Ureteroscopy with a Yag laser can be used for larger stones. Percutaneous nephrolithotomy is also used. Open surgery is rarely needed.

Causes of Urinary stone formations
Symptoms of urinary stones
Investigations and treatment of urinary stones