Diagnosis Of Kidney Stones
Medical history and physical examination
A healthcare practitioner will collect information regarding a person’s history of health conditions, family history of kidney stones, and the diet that is likely to aid in developing kidney stones. The physical examination includes:
1. General examination: In classical descriptions, a patient with renal colic (pain felt when kidney stones block the urinary tract) is continuously moving and twisting, unable to find a comfortable position. This is a common finding but not universal.
2. Vital signs: Kidney stones can induce a fast heart rate and elevate blood pressure. They generally do not cause fevers unless associated with a urinary tract infection.
3. Abdominal and flank examination: The doctor will physically examine the abdominal area.
Lab tests
Urologists often recommend several diagnostic tests to confirm the presence of kidney stones. These tests include:
1. Urinalysis: Urine tests can show whether the urine contains high levels of minerals that form kidney stones or not. It also shows white blood cells and bacteria in the urine that may indicate a urinary tract infection.
2. Blood tests: These tests are done to check the functioning of kidneys and the levels of substances that could cause progressions of kidney stones, such as
calcium,
phosphorus,
uric acid, and
serum electrolytes.
Blood urea nitrogen (BUN) and creatinine test help in identifying any abnormal functioning in kidneys by determining the amount of nitrogen in the blood that comes from the waste product urea.
Imaging tests
These tests may help to diagnose any issues that caused a kidney stone to form, such as a blockage in the urinary tract or any birth defects. These tests include:
1. Abdominal X-ray: An abdominal x-ray uses low levels of radiation to create a picture of the abdomen. These x-rays can show the location of kidney stones in the urinary tract but not all stones are visible in an abdominal x-ray.
2. Intravenous pyelogram (IVP): IVP is a gold standard for kidney stone detection. This test uses an X-ray and dye to visualize the images of kidneys, bladder, and ureters.
3. Abdominal Computed Tomography (CT) scan: If the stone is blocking the urinary tract, the CT scan can be used to assess the exact size and location of a kidney stone.
4. Abdominal ultrasound: An abdominal ultrasound scan offers moderate sensitivity specificity to diagnose kidney stones, although it is lower than a CT scan.
5. Abdominal magnetic resonance imaging (MRI): This test allows doctors to examine soft tissues without bones obstructing the view. This test is a safer alternative to a CT scan.
6. Nuclear functional renal scan: A renal scan involves the use of nuclear radioactive material to examine kidneys and assess their function.
7. Noncontrast computed tomography: This type of CT scan offers high sensitivity and specificity for the detection of kidney stones.
Stone analysis
If a person passes a stone or a stone is removed by surgery, testing the stone will determine its type. This information helps the healthcare provider to decide the best way to treat or prevent future stones.
