The renal arteries provide blood flow to the kidneys. Renal artery disease can cause a reduction in the flow of blood to the kidney and cause hypertension or high blood pressure. Renal artery stenosis is the most common correctable cause of hypertension. Left untreated over a period of time, renal artery disease can be a factor of kidney failure.
The renal artery ultrasound is a non-invasive, accurate scan used to check the arteries that supply blood to the kidneys. Unlike angiography or CT scanning, no injection of X-ray contrast material is used, so there is no risk of kidney damage connected with the use of the contrast material.
A patient may require a renal artery scan if they have experienced high blood pressure that has not responded well to medication, a deterioration in kidney function, an abnormal blood test, has been diagnosed with narrowing or blockage in one or both renal arteries, or has had previous renal artery surgery or endovascular treatment.
Blood-flow rates and patterns in the aorta and renal arteries are gauged using the Doppler ultrasound. The images provided by the ultrasound provides important information regarding any kidney damage resulting from poor blood-flow. Flow patterns (resistance indices) in the small vessels in the kidneys provides further details about kidney damage and the chances for kidney function recovery with therapy.
The scan checks the arteries deep in the stomach. The doctor will suggest an overnight fast to reduce any gas in the intestinal tract, and no tobacco or caffeine prior to the test. The doctor or technician performing the scan will ask the patient to lay on their side or back, or possible all three, and will move the ultrasound across the abdomen.
A complete study takes an hour or two.