Cerebral Angiography (Cerebral Angiogram)
Norm of Cerebral Angiography (Cerebral Angiogram)
Symmetric pattern of vascular circulation to the brain with no areas of absent vessels. The vessels are smooth, and there are no areas of pooling of the contrast dye (which would indicate bleeding from the vessels or aneurysm).
Usage of Cerebral Angiography (Cerebral Angiogram)
Suspected cerebral aneurysm or other cerebral vascular disease such as carotid occlusion in Behçet's disease, Churg-Strauss syndrome, Parry-Romberg syndrome, fistulas, spasms, atherosclerosis, or arteriovenous malformations; tumors of the brain; and work-up for transient ischemic attack or other neurologic signs and symptoms. The need for angiography may be suggested by brain scan findings.
Description of Cerebral Angiography (Cerebral Angiogram)
Cerebral angiography is a procedure performed in the radiology department using a special radiographic machine with a rapid biplane cassette changer. It involves a series of radiographic views of the cerebral circulation obtained after intra-arterial injection of a contrast medium and shows the patterns of circulation, any interruptions to circulation, or changes in vessel wall appearance.
Professional Considerations of Cerebral Angiography (Cerebral Angiogram)
Consent form IS required.
Risks
Allergy to contrast medium, aphasia, embolus, hematoma, hemiplegia, hemorrhage, infection, loss of consciousness, renal toxicity, transient ischemic attack.
Contraindications
Atherosclerosis; coagulopathy, dehydration; previous allergy to iodine, shellfish, or contrast medium; renal disease; hepatic disease; thyroid disease; during breast-feeding.
Precautions
During pregnancy, risks of cumulative radiation exposure to the fetus from this and other previous or future imaging studies must be weighed against the benefits of the procedure. Risk of exposure to the uterus from cerebral angiography is <10 mrad. Radiation dosage to the fetus decreases as pregnancy progresses.
Preparation
- See Client and Family Teaching.
- Have emergency equipment readily available.
- Remove all jewelry and metal objects (such as hairpins) from the client's head area.
- Obtain sterile gauze, tape, alcohol or other skin-cleansing agent, arterial catheter, razor, contrast medium, normal saline or heparinized normal saline, syringes, and automatic contrast injector.
- For clients who are unable to cooperate and especially for children, a general anesthetic may be administered by an anesthesia professional.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
Procedure
- The client is placed supine on a special radiographic table.
- A site for intra-arterial injection is selected and prepared by cleansing of the skin with 70% alcohol or povidone-iodine solution and injection of a local anesthetic.
- a. Carotid artery: The client's neck must be hyperextended by placement of a rolled towel under the shoulders, and the client'shead must be immobilized with tape.
- b. Femoral artery: The area must be shaved before cleansing. A long catheter is threaded through the femoral artery to the aortic arch.
- c. Brachial artery: The area may require shaving before cleansing. The brachial artery is the least common injection site. A blood pressure cuff is applied distal to the injection site and inflated before the injection to prevent contrast medium flow to the lower arm.
- Needle and catheter placement appropriate to the site is performed by the physician and verified by fluoroscopy.
- Contrast medium is injected, and the client is carefully observed for signs of an allergic reaction such as hives, flushing, or stridor.
- A series of radiographs of the head, both anterior and lateral views, are taken during the 5–15 seconds after the injection. Approximately another 6 seconds after the arteries appear, capillary and venous blood flow may be studied by radiographs.
- The contrast injection may be repeated, and the views varied to complete the study, as indicated by the suspected abnormalities.
- The artery catheter is kept open with continuous or intermittent flushing or with heparinized normal saline.
Postprocedure Care
- The catheter is withdrawn and pressure is applied to the artery for at least 15 minutes.
- Apply a dry, sterile or pressure dressing to the site and observe for bleeding or hematoma formation at the catheter insertion site.
- Maintain bed rest for 12–24 hours.
- Assess neurologic status and vital signs hourly for 4 hours and then every 4 hours for 20 hours.
- For femoral or brachial approaches, immobilize the leg or arm straight for 12 hours. Check color, motion, temperature, sensation, and distal pulses of the immobilized extremity every 15 minutes for 4 hours, then every 30 minutes for 2 hours, then every 1 hour for 4 hours, and then every 4 hours for 12 hours.
- For the carotid approach, observe for respiratory distress, dysphagia, or hoarseness, which may indicate extravasation of the dye.
- If general anesthesia was used, continue the assessment of respiratory status and follow institutional protocol for post sedation monitoring. Typical monitoring includes continuous ECG monitoring and pulse oximetry, with continual assessments (every 5–15 minutes) of the airway, vital signs, and neurologic status until the client is lying quietly awake, is breathing independently, and responds appropriately to commands spoken in a normal tone.
Client and Family Teaching
- Fast from food and fluids for 4–8 hours before the procedure.
- It is important to lie still for this test. A sensation of burning may be felt because of the injection of the contrast medium, but this feeling lasts for only a few moments.
Factors That Affect Results
- Head movement during the study obscures the clarity of the radiographs.
- Radiopaque objects such as earrings obstruct the view of the internal vasculature.
Other Data
- The femoral artery approach has the advantage of providing visualization of both carotid arteries and both vertebral arteries, extending the study to the supply vessels.
