What tests should be done for kidney stone reexamination

Patients with kidney stones must cooperate with the doctor's treatment in order to fully recover from the kidney stones and restore their kidneys to normal levels. In the treatment of kidney stones, stone-removing drugs and lithotripsy are generally used. After drug control and surgical treatment, patients should also choose the right time for a follow-up examination to see if there are any kidney stones inside the body. What are the main examination items that need to be done during the follow-up examination for kidney stones?

Examination items: B-ultrasound, ureterography

Laboratory tests:

Urine tests can be divided into general tests and special tests

General examination: Mainly urine routine: it includes pH, relative density (specific gravity), red blood cells, pus cells, protein, sugar, crystals, etc. Hematuria, crystalluria and pus cells can be found in the urine of patients with urolithiasis. The level of urine pH often indicates a certain type of stone: the urine pH of patients with calcium phosphate and carbonate apatite stones is often higher than 7.0; while the urine pH of patients with uric acid, cystine and calcium oxalate stones is often less than 5.5. Microscopic or gross hematuria may be seen. However, 15% of patients did not have hematuria. In non-infectious stones, there may be mild pyuria.

What are the examination items for kidney stones? How big a kidney stone is required for surgery?

Special tests include:

Urine crystal examination: Fresh urine should be collected. If benzene-like cystine crystals are seen, it may indicate cystine stones; if uric acid crystals are found in the urine, it often indicates the possibility of uric acid stones; if envelope-like crystals are found, it may be calcium oxalate dihydrate stones; coffin-lid-like crystals are ammonium magnesium phosphate crystals; sulfonamide crystals will be found in the urine of patients suspected of having sulfonamide stones.

Urine bacterial culture: colony count >105/ml is positive. Susceptibility testing can help identify the most effective antibiotics. If urine culture shows urea-producing bacteria, there is a possibility of infected stones.

24-hour urine test: 24-hour urine must be collected correctly and the urine measurement must be accurate. The test contents include: 24h urine calcium, phosphorus, magnesium, citrate, uric acid, oxalic acid, cystine, etc.

Blood biochemistry test

The normal serum calcium level in adults is 2.13-2.6 mmol/L (8.5-10.4 mg/dl), and the inorganic phosphorus level is 0.87-1.45 mmol/L (2.7-4.5 mg/dl). The serum calcium of patients with primary hyperparathyroidism is higher than normal, often above 2.75mmol/L (11mg/dl), and is accompanied by a decrease in serum inorganic phosphorus.

What are the examination items for kidney stones? How big a kidney stone is required for surgery?

Normal serum uric acid levels in male adults do not exceed 16.36mmol/L (7mg/dl), while for females, it does not exceed 386.62mmoL/L (6.5mg/dl). When this value is exceeded, it is hyperuricemia. Patients with gout have elevated blood uric acid levels.

When kidney stones are accompanied by renal dysfunction, acidosis is often present. At this time, serum electrolytes change, serum sodium and carbon dioxide binding capacity decreases, and blood potassium increases to varying degrees. Hypokalemic and hyperchloremic acidosis may occur in renal tubular acidosis.

The determination of urea nitrogen and creatinine can help understand the patient's renal function. When renal function is damaged, urea nitrogen and creatinine in the blood may increase to varying degrees. %20 In short, blood and urine tests of patients with urinary stones can help to understand the renal function of patients with urinary stones, whether the stones have concurrent infections, the possible types of stones and the causes of stones, and play a role in guiding the treatment and prevention of stones.

Other auxiliary examinations:

X-ray examination

X-ray examination is the most important method for diagnosing urinary stones. Including abdominal plain film, excretory urography, retrograde pyelography, or percutaneous renal puncture angiography.

Urinary tract X-ray: Urinary tract X-ray is the most basic method for diagnosing urinary tract stones. Based on the X-ray opaque shadows in the kidney, ureter, bladder, and urethra, a preliminary diagnosis of the presence or absence of stones can be made. The calcium content in the stones varies, and the degree of X-ray transparency is also different. About 40% of the stones can be judged by the composition based on the dense shadows shown on X-ray films. Calcium oxalate stones are the least X-ray transparent, followed by ammonium magnesium phosphate; uric acid stones are the most common X-ray transparent stones. Cystine stones are slightly opaque to X-rays because they contain sulfur. However, indinavir stones and some matrix stones can be visualized on plain scan CT films. Renal calcification is common in medullary sponge kidney (deposits close to dilated collecting ducts). It can also be compared with the density of the lumbar transverse process to make a diagnosis. Another 10% of stones that do not contain calcium are not easily detected by X-rays.