Clinical Instructions — Angiography: A Guide for Patients
What Is An Angiogram?
An angiogram is a type of x-ray image that precisely demonstrates the arteries and veins in a specific organ or body part. It is performed by a radiologist with subspecialty training in invasive techniques. Specialized x-ray equipment with computerized and rapid serial imaging capability is used to perform this study.
When Should I Get An Angiogram?
Since angiography is an invasive technique, it is recommended only in specific situations when precise information regarding blood vessels is required, and when this precision cannot be adequately provided by noninvasive imaging techniques such as magnetic resonance imaging, computed tomography, or ultrasound. Examples of specific conditions that are investigated by angiography include cerebral vascular disease (such as stroke, aneurysm, or hemorrhage into the brain), vascular malformations, highly vascular tumors (tumors with a large blood supply), bleeding from a variety of causes, hypertension (high blood pressure), and other symptoms that may be caused by inadequate blood supply. Diagnostic angiography is often combined with a therapeutic procedure that is performed through the same catheter (such as aneurysm coiling, embolization, carotid/intracranial stenting, or angioplasty).
Is It Safe? Will It Hurt?
Angiography, when performed by properly trained and experienced physicians, is a safe procedure with no significant long-term side effects. However, as with any other invasive procedure, complications can occur. These will be explained to you in detail before you give your consent for the procedure. The patient who is not under general anesthesia may experience mild discomfort during injection of the local anesthetic (numbing medication), which precedes the insertion of the catheter. The remainder of the examination is not painful, although the patient must lie very still during the procedure. After the angiogram is completed, there may be some mild discomfort (similar to a bruise) at the catheter site.
How Should I Prepare For The Procedure?
You will be given detailed written instructions regarding time and place of arrival and dietary preparation. In general, patients are asked not to eat solid food for 8 hours prior to the procedure and to stop drinking clear fluids 6 hours before the procedure. A neurointerventionalist will explain the procedure in detail and obtain your signed consent (permission) before the procedure.
What Will Happen During The Procedure?
Initially, an intravenous line is started in the hand or arm. Patients are given medication through this intravenous line to help them relax or go to sleep. The area where the catheter will be inserted (usually at the right hip) is washed with an iodine solution and the patient is covered with sterile drapes in order to prevent infection. Local anesthetic is injected into the skin, and once the area has been numbed, the neurointerventionalist passes a needle into the artery. The needle is then replaced with a catheter (small hollow tube) that the radiologist guides into the appropriate blood vessel to allow series of images to be taken. Once the examination is completed, the radiologist removes the catheter and applies some pressure to the catheter entry site in order to prevent bleeding. The patient is then transported to the Recovery Room/Short Stay Unit and is asked to lie still without bending the leg for 4 to 6 hours.
How Does This Technique Work? What Does The Radiologist See?
Angiographic images are made by special computerized x-ray equipment. The computer subtracts the x-ray image of the body from the x-ray of the injected contrast medium, creating an image of just the injected blood vessels. Each image shows the blood vessels in a different phase of circulation (from atrial through venous). The radiologist is then able to determine the nature and location of any abnormalities of the blood vessels, such as aneurysms, arteriovenous malformations (AVM), arteriovenous fistulas, or blood vessel stenosis or occlusions.
How Will I Learn The Results?
You will learn the results from your neurointerventionalist performing the procedure or referring physician. The results will be available to your physician immediately after the procedure, although in complex situations, it may require a few hours for the neurointerventionalist to complete the process and interpret the films.
What If I Have Other Questions?
To obtain additional information before or after the angiogram, contact 617 638 6595 or 617 414 4632.
BMC Physicians performing cerebral and spinal angiography
Thiex R, Norbash AM, Frerichs KU. The safety of dedicated-team catheter-based diagnostic cerebral angiography in the era of advanced noninvasive imaging. Am J Neuroradiol 2010;31:230-4.