What Is Magnetic Resonance Angiography?
Magnetic resonance angiography (MRA) is a non-invasive diagnostic treatment that visualizes blood arteries using a blend of magnetic resonance technology (MRI) and intravenous (IV) contrast dye. On a magnetic resonance imaging (MRI) scan, contrast dye makes blood vessels seem opaque, allowing the physician to see the blood vessels that are to be assessed. Magnetic resonance angiography is commonly used to monitor blood flow and check the heart and other soft tissues.
Why Is Magnetic Resonance Angiography Performed?
Magnetic resonance angiography may be recommended if the healthcare professional suspects that a constriction or blockage of blood arteries somewhere in the body is present. Doctors also use magnetic resonance angiography (MRA) to look for the following conditions:
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Arteriovenous malformation in the brain or elsewhere in the body.
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Plaque or atherosclerotic disease in the carotid artery present in the neck can reduce blood flow to the brain and result in a stroke.
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Irregularities in the aorta, such as aneurysms, both in the abdomen and chest or in other arteries.
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Plaque disease in the leg arteries and aid in preparation for angioplasty or stent implantation or surgery.
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Trauma to one or more arteries in the chest, abdomen, neck, or pelvis following any accident.
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Aortic dissection or splitting in the chest or belly, as well as its primary branches.
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Amount and severity of coronary artery disease, as well as its consequences, while arranging for a procedure such a coronary bypass or stenting.
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Pulmonary embolism or pulmonary arteriovenous malformations.
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Congenital anomalies in blood vessels of children.
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Stenosis and vascular blockages.
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Coarctation of the aorta.
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High blood pressure and renal failure can occur as a consequence of renal artery stenosis.
How to Prepare for the Procedure?
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Eat, drink, and take medications normally.
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One must change entirely into a patient gown and secure all personal items. They will be given a robe and a locker. All piercings should be removed, and valuables should be left behind at home.
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The imaging procedure takes place inside a huge tube-like structure that is open on both of its ends. For high-quality photos, one must lie totally still. Earplugs are essential and will be provided because the machine is extremely loud.
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A contrast agent is a particular liquid that is injected into a vein through an intravenous (IV) line, which is a tiny tube. Discomfort, warmth or tingling in the lips, tingling in the arm, metallic aftertaste in the mouth, nausea, or headache may be experienced by certain people. These signs and symptoms fade swiftly.
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If one has an allergic response to contrast that necessitates medical care, contact the ordering physician for the suggested prescription to take orally 24 hours, 12 hours, and two hours before the exam.
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If one needs an anti-anxiety medicine due to claustrophobia, get a prescription from the ordering physician. Please note that the patient will require transportation home.
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The test may be delayed, rescheduled, or canceled upon arrival if the patient has metal in their body that was not revealed prior to the appointment.
Depending on the situation, the doctor may recommend further preparation.
What Happens During Magnetic Resonance Angiography?
Magnetic resonance imaging (MRI) does not employ radiation, unlike X-rays and computed tomography (CT) scans. Radio waves, on the other hand, realign hydrogen atoms that already exist in the body. There are no chemical alterations in the tissues as a result of this.
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Depending on the type of tissue, the hydrogen atoms produce varying amounts of energy as they return to their normal alignment. This energy is captured by the scanner, which uses it to build a picture.
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The magnetic field is created in most MRI machines by sending an electric current through wire coils. Other coils are present within the machine and, in some situations, around the bodily component being scanned. These coils receive and send radio waves, resulting in signals that the machine detects.
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The patient does not make contact with the electric current. The signals are processed by a computer, which generates a succession of images, each of which depicts a tiny slice of the body.
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The radiologist can examine these photos from several perspectives. Contrast material is used to make the blood vessels under examination stand out by turning them bright white.
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This test is normally done as an outpatient procedure. Individuals will be placed on the mobile exam table by the technologist. Straps and bolsters may be used to keep patients still and maintain their position.
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Devices with coils competent for transmission and reception of radio waves can be put around or near the area of the body that the technologist is examining. Magnetic resonance imaging or MRI examination often contains multiple runs, some of which span for several minutes. Each run will feature its own set of audio.
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If the exam requires contrast material, a doctor, nurse, or technologist will insert an intravenous (IV) catheter into a vein of the arm or hand. This intravenous line will be used to administer the contrast material. The patient will be inserted into the magnetic resonance imaging (MRI) unit.
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The test will be performed while the technologist is working on a computer outside the room. An intercom will allow the patient to communicate with the technologist. After an initial set of scans, the technologist will inject the contrast material into the intravenous (IV) line. More photos will be taken during or after the contrast material injection.
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After finishing the exam, the technologist might ask the patients to wait while the radiologist reviews the images to evaluate whether any more ones are needed. After the exam, the technologist will remove the Intravenous line and apply a tiny dressing to the insertion site. The entire test normally takes about 60 minutes to complete.
What Happens After Magnetic Resonance Angiography?
The images obtained from the magnetic resonance angiography (MRA) will be examined by the healthcare provider. A normal test result comes when no obstructions or anomalies are discovered. An abnormal result indicates that the healthcare professional noticed a problem with one or more of the body's blood vessels. This could indicate that the patient has atherosclerosis, artery hardening, or another circulation condition. Based on the precise problem that is detected, the healthcare professional may most likely recommend more testing or treatments.
What Are the Benefits of Magnetic Resonance Angiography?
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MRI is a non‐invasive technology that does not require radiation exposure.
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Without needing to put an Intravenous catheter into the blood vessels, detailed pictures of many blood vessels and blood flow can be obtained. When necessary, a tiny Intravenous catheter is placed into a small vein in the arm so that no major blood vessels are harmed.
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Magnetic resonance imaging (MRI) gadolinium contrast material is less likely to generate an allergic reaction than X-ray and CT scanning iodine-based contrast materials.
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MRA can generate valuable, high-quality pictures of many blood arteries even without the use of contrast material. This makes it especially beneficial for those patients who are allergic to certain foods or have impaired renal or hepatic function.
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Catheter angiography is more expensive than magnetic resonance angiography.
What Are the Risks Involved With Magnetic Resonance Angiography?
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When proper safety criteria are followed, the MRI exam provides essentially no risk to the ordinary patient.
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There is a risk of utilizing too much sedative. The vital signs, however, will be watched to reduce this danger.
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Patients will not be harmed by the strong magnetic field. It may cause implanted medical devices to become dysfunctional or create picture distortion.
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Nephrogenic systemic fibrosis is a popular side effect of gadolinium contrast injection. With the introduction of newer gadolinium contrast agents, it is quite rare. It is most common in persons with advanced renal disease. Before considering a contrast injection, the doctor will thoroughly analyze the kidney function.
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Despite the fact that there are no major health risks, data suggest that extremely minute levels of gadolinium can persist in the body, particularly the brain, after many MRI tests. This is most common in patients who have repeated MRI tests throughout the course of their lives to monitor chronic or high-risk health issues. The kidneys are the primary route of elimination for the contrast agent. If you fall into this category, talk to your doctor about gadolinium retention, as this impact varies from patient to patient.
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If the exam includes contrast material, there is a small chance of an allergic reaction. The majority of these reactions are moderate and may be managed with medication. If a patient experiences an allergic response, the doctor will be on hand to help the patient right away.
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Breastfeeding should be avoided for 24 to 48 hours after receiving IV contrast material, according to manufacturers. However, studies demonstrate that the quantity of contrast absorbed by the newborn during breastfeeding is exceedingly minimal.
Conclusion:
Many arteries throughout the body, including the cerebral, aorta and its major branches in the thorax and abdomen, renal arteries, and the arteries in the lower limbs, have been successfully studied using magnetic resonance angiography (MRA). The procedure, however, has had less success in the coronary arteries than computed tomography (CT) angiography or invasive catheter angiography. Atherosclerosis is the most common underlying disease; however, other medical disorders such as aneurysms or aberrant vascular anatomy can also be detected. The examination is non-invasive, which is an advantage of magnetic resonance angiography (MRA) over invasive catheter angiography.
