What is cerebral angiography?
Cerebral angiography is a medical imaging procedure that uses a special dye, known as contrast material, and x-rays to visualize the blood vessels in the brain and how blood flows through them. It is typically performed in a hospital or radiology center. During the procedure, a patient lies on an X-ray table with their head stabilized. A sedative may be given to help the patient relax, and an electrocardiogram (ECG) is used to monitor heart activity.
A catheter is inserted into an artery, usually in the groin, and guided to the arteries in the neck. Once in place, the contrast dye is injected through the catheter, and X-ray images are taken to observe the flow of the dye through the brain’s blood vessels, which can reveal any blockages or abnormalities. This procedure is often used to identify or confirm issues with the blood vessels in or around the brain, such as aneurysms, vascular malformations, or narrowing of the arteries .
Cerebral angiography is utilized for the diagnosis of a variety of conditions
Cerebral angiography is utilized for the diagnosis of a variety of conditions that involve the blood vessels of the brain. Some of the diseases and conditions commonly diagnosed with cerebral angiography include:
- Cerebral Aneurysms: A localized bulging in the blood vessel wall that can be life-threatening if it ruptures.
- Vascular Malformations: Abnormalities in the circulatory system that occur during embryonic or fetal development.
- Vascular Tumors: Tumors that involve the blood vessels, which can be benign or malignant.
- Strokes and Stroke-Related Syndromes: Conditions that result from the blockage or rupture of a blood vessel in the brain, leading to a lack of blood flow and oxygen to brain tissue.
- Atherosclerotic Stenosis: Narrowing of the arteries due to plaque buildup, which can restrict blood flow.
- Vasculopathy: A general term for diseases that affect blood vessels, including inflammation and degeneration.
- Cerebral Vasospasm: A condition where the blood vessels in the brain constrict, often after a subarachnoid hemorrhage.
- Acute Ischemic Stroke: A type of stroke caused by a blockage in an artery supplying blood to the brain.
Cerebral angiography provides detailed images of the blood vessels, allowing specialists to observe the blood flow and identify any abnormalities. It is considered a highly precise diagnostic tool for these conditions and is often used when other imaging modalities are inconclusive or when a detailed analysis of the vasculature is required.
Who should consider undergoing a cerebral angiography examination?
- Individuals suspected of having vascular issues such as cerebral infarction, subarachnoid hemorrhage, posterior circulation ischemia, and cerebral hemorrhage;
- Those who have had carotid ultrasound, CTA, or MRA examinations that reveal stenosis, occlusion, aneurysms, or vascular malformations in the head and neck vessels;
- Patients with acute cerebral infarction who require emergency mechanical thrombectomy, stent placement, or arterial thrombolysis;
- Patients who need to understand the blood supply of brain tumors and their relationship with nearby vessels;
- Patients with head and facial tumors who require surgical resection and have rich blood supply in the head and face;
- Individuals with symptoms such as headache accompanied by brain buzzing, sudden protrusion of one eye, or eyelid ptosis, suspected to be caused by cerebrovascular diseases;
- Patients who need follow-up examinations after treatment for head, face, and intracranial vascular-related diseases.
Step-by-step description of the process of Cerebral angiography
Cerebral angiography is a specialized neuroradiological procedure that provides detailed images of the blood vessels in the brain. Here is a step-by-step description of the process:
- Preparation: Before the procedure, a patient will be positioned on an X-ray table. Their head is held still using a strap, tape, or sandbags to prevent movement during the procedure. A mild sedative may be administered to help the patient relax, and an electrocardiogram (ECG) is used to monitor heart activity .
- Access: An area of the body, typically the groin, is cleaned and numbed with a local anesthetic. A thin, hollow tube called a catheter is then inserted through an artery, usually in the femoral artery .
- Catheter Advancement: The catheter is carefully advanced through the artery, guided by low-dose X-rays, towards the blood vessels in the neck and then into the cerebral arteries. This process is carefully monitored to ensure the catheter reaches the correct position .
- Contrast Injection: Once the catheter is in place, a contrast medium, or “dye,” is injected through the catheter into the blood vessels. This contrast agent helps to visualize the blood vessels more clearly on X-ray images .
- Imaging: X-ray images are taken as the contrast agent travels through the arteries and veins. These images provide a detailed view of the blood flow and can reveal any blockages or abnormalities.
- Digital Subtraction Angiography (DSA): Sometimes, a technique called DSA is used. This involves taking an initial image before the contrast injection and then subtracting it from subsequent images taken after the contrast injection. This process enhances the visibility of the blood vessels and removes the surrounding bone and tissue.
- Completion: After the X-ray images are taken, the catheter is carefully withdrawn. Pressure is applied to the insertion site to stop any bleeding, and a tight bandage is applied. The patient’s leg is usually kept straight for a few hours after the procedure to prevent complications.
- Recovery: The patient is then moved to a recovery area for monitoring. The recovery process is typically a few hours long, and the patient can usually go home after this period.
- Follow-up: After the procedure, the patient is advised to watch the insertion site for signs of bleeding or hematoma. It is also important to monitor for any allergic reactions to the contrast material or complications related to the procedure.
Cerebral angiography is a valuable diagnostic tool for a range of conditions, including aneurysms, arteriovenous malformations, stroke, and other vascular abnormalities. It is performed by highly trained specialists in a controlled medical environment to ensure patient safety and optimal results.
Post-cerebral angiography:
After the angiography is completed and you return to the ward, you can drink plenty of fluids as per the doctor’s orders. Pay attention to the following four points:
- Patients should lie flat and keep the puncture limb immobilized for no less than 8 hours (with a regular salt bag compression, the immobilization time can be greatly reduced after using a compression device); patients who have had radial artery puncture can walk back to the ward on their own.
- Regularly check the puncture site and the pulse of the artery distal to it to detect abnormalities promptly. Generally, this should be done every 15 minutes for four times; then every 30 minutes for two times; and then every hour for two times. (If any of the following situations occur, notify the doctor immediately: a. bleeding or hematoma formation at the puncture site, b. no palpable pulse distal to the puncture site.)
- Monitor vital signs: start with checks every half hour for two consecutive times, then gradually reduce the frequency. The puncture site after cerebral angiography needs to be compressed for over 8 hours to prevent bleeding. Observe whether there is any seepage of blood, hematoma around the puncture site, the condition of the pulse at the puncture site, and the skin temperature of the puncture limb. If no abnormalities are found after 8 hours, you can start to move around. (Since the angiography examination requires local anesthesia, to alleviate the back pain that most patients experience while lying flat after the operation, except for the immobilization of the puncture limb, the rest of the limbs and the head can move, as long as the puncture limb is not pulled during the activity.)
- Also, pay attention to maintaining the cleanliness and dryness of the perineal area, bladder, urethra, and anus to avoid contaminating the puncture area.
Clinical significance
Cerebral angiography is crucial for diagnosing and planning treatment for a range of cerebrovascular disorders. This imaging technique is particularly important for the following reasons:
- Diagnosis: Cerebral angiography helps in the accurate diagnosis of conditions such as aneurysms, arteriovenous malformations (AVMs), stenosis, and occlusion of cerebral arteries. It can reveal the size, shape, and location of these abnormalities, which is essential for determining the appropriate treatment approach.
- Treatment Planning: The detailed images obtained from cerebral angiography are invaluable for surgeons and interventional radiologists in planning surgical or endovascular interventions. For example, it can guide the placement of stents, coils, or other devices to treat aneurysms or occlusions.
- Monitoring: In some cases, cerebral angiography is used to monitor the effectiveness of treatments or to assess changes in vascular conditions over time.
- Research: This technique also contributes to medical research by providing insights into the pathophysiology of cerebrovascular diseases and the outcomes of various treatments.
Overall, cerebral angiography is a vital tool in the management of cerebrovascular diseases, offering precise visualization that aids in both diagnosis and treatment planning.
Equipment and suppliers
The following equipment is required for this procedure:
- Angiography Machine: This is the primary equipment used to obtain high-resolution images of the blood vessels.
- Digital Subtraction Angiography System (DSA): Used to enhance the clarity and contrast of the images.
- Catheters: Used to inject the contrast agent into the blood vessels.
- Contrast Agents: Used to enhance the visibility of the blood vessels in the images.
- Injector: Used to precisely control the injection speed and volume of the contrast agent.
- Monitoring Equipment: Such as ECG and blood pressure monitors, used to monitor the patient’s vital signs during the procedure.
- X-ray Equipment: Used to obtain the images.
- Computers and Imaging Software: Used to process and store the image data.
In the United States, there are several domestic suppliers that provide this equipment, including but not limited to:
- GE Healthcare: Provides a variety of medical imaging equipment, including cerebral angiography machines and DSA systems.
- Siemens Healthineers: Offers comprehensive imaging solutions, including equipment for cerebral angiography.
- Philips Healthcare: Provides advanced imaging equipment and technical support.
- Canon Medical Systems USA: Supplies various medical imaging equipment, including cerebral angiography systems.
These companies have extensive operations and support networks in the United States and can provide the necessary equipment and technical support.