A carotid angiogram is a specialized diagnostic imaging procedure that generates detailed pictures of the carotid arteries in the neck. These large arteries supply oxygen-rich blood directly to the brain. The angiogram is an invasive test that uses X-ray technology and a contrast agent to visualize the interior of these vessels. This provides physicians with a precise map of the arterial structure, allowing for the identification of problems affecting blood flow.
Medical Purpose and Indications
Physicians often order a carotid angiogram when non-invasive tests, such as ultrasound, suggest a problem but lack the necessary detail for diagnosis or treatment planning. The procedure identifies structural abnormalities within the carotid arteries that may impede blood circulation to the brain. This includes detecting stenosis, which is the narrowing of the artery typically caused by plaque buildup.
The test also diagnoses an aneurysm—a balloon-like bulge in the vessel wall—or identifies other vascular malformations. By outlining the extent of damage, the angiogram helps assess a patient’s risk of experiencing a stroke or a transient ischemic attack (TIA). The images help determine if a patient requires a surgical intervention, like an endarterectomy, or a minimally invasive procedure, like stenting, to restore proper blood flow.
Preparing for the Angiogram
Preparation ensures the safety and accuracy of the angiogram. Patients are instructed not to eat or drink anything for six to eight hours before the procedure. This fasting minimizes the risk of aspiration, especially if sedation is administered.
Patients must discuss current medications with the medical team, particularly blood thinners, which may need to be temporarily stopped several days prior to the test to mitigate bleeding risk. Patients with diabetes taking insulin or oral medications will receive specific instructions on adjusting their dosage. Blood tests, often checking kidney function, are performed beforehand because the kidneys clear the contrast dye used during the test. Since a mild sedative is often given, patients must arrange for a responsible adult to drive them home and stay with them for the first 24 hours.
How the Procedure is Performed
The carotid angiogram is performed in a specialized suite. The patient lies on an X-ray table and is connected to monitoring equipment that tracks heart rate and blood pressure. An intravenous line is placed in the arm to administer fluids and a mild sedative. The most common access site is the femoral artery in the groin, though sometimes a wrist artery is used.
After the access site is sterilized, a local anesthetic is injected to numb the area. This may cause a brief stinging sensation. The physician makes a tiny puncture and inserts a thin, flexible tube called a catheter into the artery. Using live X-ray guidance, known as fluoroscopy, the physician navigates the catheter up to the origin of the carotid arteries in the neck.
Once the catheter is positioned, a contrast dye is rapidly injected through the tube. This iodine-based liquid travels into the carotid vessels, making them temporarily visible on the X-ray screen. This allows the physician to view blood flow and identify abnormalities. Patients frequently report a temporary sensation of warmth or flushing in the head and neck as the dye flows.
The physician captures a series of images as the dye moves through the vessels, creating a dynamic “road map” of the circulation. When the images are obtained, the catheter is removed. Firm pressure is immediately applied to the access site to prevent bleeding.
Recovery and Post-Procedure Care
Following the procedure, the patient is moved to a recovery area for observation. The medical team monitors vital signs and checks the puncture site for bleeding or swelling. Patients must remain lying flat in bed for several hours (typically two to six hours), depending on the artery closure method used. Keeping the limb still and straight during this time helps the puncture seal properly and minimizes the risk of a hematoma.
Once discharged, patients should avoid strenuous activities like heavy lifting or intense exercise for several days. If the groin was the access site, avoid bending sharply at the hip or straining for the first 24 to 48 hours. Patients are encouraged to drink extra fluids to help flush the contrast dye from their system. Clear instructions are provided on caring for the puncture site, including when it is safe to shower and signs that warrant immediate medical attention, such as persistent bleeding, numbness, or significant swelling.