A renal angiography is a diagnostic imaging test that is performed to check for signs of blood vessel abnormalities in the kidneys. The test involves injecting a specialized type of dye into a renal artery and then taking x-rays of the abdomen. The dispersion of dye within the blood vessel shows up on the x-ray, and doctors can visualize the type and amount of damage involved. Renal angiography is commonly used to identify narrow blood vessels, ruptures, tumors, and several other types of kidney problems.
The test is performed by a specially trained radiologist, usually in an inpatient hospital setting. Operating room personnel first shave and wash a section of skin above the groin and give the patient either a localized or general anesthetic. With the aid of real-time x-ray images, a hollow needle is inserted into an artery and a thin wire is guided through the needle. The radiologist then removes the needle and slides a plastic tube called a catheter over the wire. Contrast medium, a chemical dye that shows up on x-rays, is pumped through the catheter to the artery.
Once the contrast medium is in circulation, the radiologist can turn on the main x-ray machine. Several x-ray images are taken of the kidneys before the catheter is removed. The radiologist puts pressure on the groin to stop bleeding and bandages the entry point. The entire renal angiography procedure can usually be performed in less than one hour.
After a renal angiography, the radiologist and other specialists can review x-ray findings. The contrast medium shows up well on x-rays, allowing doctors to clearly track the flow of blood through the kidneys. Based on the path of the dye, any blood clots, unusual masses, or narrow arteries can be easily identified. The results of renal angiography help doctors determine the most appropriate course of treatment.
In many cases, renal angiography indicates that surgical repair is needed. Surgeons may try to excise a tumor, repair weakened blood vessel walls, or replace a section of badly damaged tissue. A common procedure called angioplasty involves the insertion of a synthetic stent into a narrow vessel to open it up and let blood flow more freely.
Renal angiography is a valuable tool that can significantly improve doctors' confidence in a diagnosis and ensure a patient receives the best possible treatment. In addition, a radiologist can perform angiographies periodically during the recovery phase to make sure treatments are successful. Emerging technological advances in medical equipment will likely make the procedure even more accurate and less invasive in the future.