How are kidney stones diagnosed?
Diagnosis starts with a physical exam and review of your medical history. Other tests include:
- Blood test: to measure how well your kidneys are functioning, to look for signs of infection, and to look for biochemical problems that lead to forming kidney stones.
- Urine sample test: to look for signs of an infection and to examine the levels of the stone-forming substances – calcium, oxalate, urate, cysteine, xanthine, and phosphate.
- Imaging tests: to see the size, shape, and location of the stones; determine the most suitable treatment, and sometimes to review the result of treatment. Types of imaging tests used are X-rays, CT scan, and ultrasound. Both X-ray tests and CT scans use a small amount of radiation to create their images.
Two types of X-rays are used: a standard X-ray of the urinary tract or a special type of X-ray called an intravenous pyelogram (IVP). If an IVP is ordered, you receive an injection of a dye in your vein before the X-ray is taken. The dye is used to get a sharper image of problems in the kidneys, ureters, and bladder resulting from urine being blocked.
A CT scan of the abdomen is an imaging test that creates a 3-dimensional view of the organs within the abdominal cavity. It is used with or without the injection of a dye in your vein. This test shows the stone size and location and conditions that may have caused the stone to form. In addition, the other organs within this area of the body can be evaluated.
An ultrasound of the urinary tract uses sound waves to detect kidney stones and indirect signs of kidney stones, such as changes in the kidney’s size and shape.