February 9, 2024
February 8, 2024

MRA vs MRI: What’s the Difference?

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MRA vs MRI: What’s the Difference?

When it comes to diagnostic imaging, magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) are advanced techniques for visualizing blood vessels and soft tissues. While both methods utilize magnetic and radio frequency fields to create detailed images of the structures inside your body, they have important differences in their applications and capabilities. 

Here, we’ll cover the topic of MRA vs MRI, the benefits and risks, and how MRIs are used in cutting-edge proactive healthcare. 

What Are the Differences Between an MRA vs MRI?

MRA specifically focuses on imaging blood vessels, providing valuable insights into their structure, function, and potential abnormalities. Using magnetic fields and radio waves, MRAs produce high-resolution images that allow radiologists to assess blood flow, detect blockages or aneurysms, evaluate for heart disease (including blockages in the coronary arteries), and identify other vascular conditions.

On the other hand, MRI is a broader imaging technique encompassing various applications beyond visualizing blood vessels. It can provide images that show the body's organs, tissues, and joints in great detail. An MRI scan is often used to diagnose various medical conditions such as cancer tumors, neurological disorders, musculoskeletal injuries, or diseases.

5 Common Considerations and Risk Factors for MRA and MRI Scans

MRA and MRI machines share similar technology as they use the same equipment and are considered safe, non-invasive procedures. While they offer valuable diagnostic insights, there are common considerations and potential risk factors that apply to both these imaging techniques.

1. Pregnancy

The American College of Obstetricians and Gynecologists suggests that imaging pregnant patients should be done on a case-by-case basis, and the decision on the risk-benefit ratio should be made by the physicians involved. There are no known biological effects of MRI on fetuses. However, the contrast agent gadolinium should be avoided during pregnancy.

2. Patient Cooperation

MRA and MRI procedures require patients to remain still for an extended period. The ability to stay motionless ensures the production of clear and accurate images. Patients should communicate concerns to the healthcare team to enhance the overall experience. 

Both MRI and MRA scans can take 20–60 minutes. For patients receiving contrast material, it may take a bit longer since they’ll have to start an IV and get into position. Scan time can also vary depending on the study and the body area. For example, an MRA of the brain will take approximately 15 minutes.

3. Noise Levels

MRI and MRA machines can generate significant noise during the imaging process. As such, patients are usually provided with earplugs or have the option to use headphones. Understanding the noise levels beforehand can ensure a more comfortable experience.

4. Claustrophobia

MRA vs MRI: nurse preparing her patient for an MRI scan

The enclosed space of an MRI scanner may cause anxiety or claustrophobia in some people. Open MRI machines are available as an alternative for those who find traditional MRI machines too confining.

5. Metal Interactions

Both MRA and MRI use strong magnetic fields, making the presence of certain metal objects a concern. It's essential to remove all metal items before the scan. Not all metal is magnetic, but it's important to inform your radiology technologist about any of these items to assess potential risks and take appropriate precautions.

  • Metal piercings or embeds may need to be removed to avoid discomfort and movement during the procedure.
  • Medical devices, like insulin pumps, glucose monitors, and others, may contain metal components that can interfere with imaging.
  • Metallic implants, including screws or plates from surgeries, may distort the images and may cause pain or injury. Even non-ferrous metal can interact with the radiofrequency field and heat up.
  • The strong magnetic field in both MRA and MRI scans may also interfere with the function of pacemakers, posing potential risks.
  • Metal joint replacements can cause artifacts in the images, impacting the clarity of the diagnostic information.
  • Tattoos and permanent makeup may contain metal components, and during MRI, there is a risk of heating due to the magnetic field.

What Does an MRI Scan Show?

An MRI is a versatile imaging technique. Here are some of the areas an MRI is especially good at examining. 

Soft tissues: An MRI scan excels at visualizing soft tissues, including organs, muscles, ligaments, tendons, and nerves. It offers high contrast resolution, making it ideal for detecting more nuanced abnormalities, like when you’re worried about a lump under the skin.

Brain and spinal cord: An MRI helps visualize the brain and spinal cord to assist in the diagnosis of conditions such as tumors, inflammation, or degenerative disorders.

Joints: MRI scans are frequently employed to assess joints, helping identify issues like arthritis, torn ligaments, or cartilage damage.

Abdominal and pelvic organs: An MRI provides detailed images of organs in the abdomen and pelvis, aiding in the diagnosis of conditions affecting the liver, kidneys, pancreas, and reproductive organs.

Breasts: A breast MRI is a supplemental imaging tool for breast cancer detection, especially in high-risk individuals, or to further assess abnormalities found in mammography.

What Can an MRA Show That an MRI Cannot?

MRA vs MRI: illustration of the circulatory system

Magnetic resonance angiography is a special type of MRI that helps radiologists visualize blood vessels and assess blood flow. While MRA shares similarities with MRI, its unique focus on vascular structures allows it to detect certain conditions that standard imaging tests may not reveal with the same level of detail. Here are some aspects an MRA can detect that a conventional MRI might not capture as effectively.

Vascular Abnormalities and Blood Flow Dynamics

MRA is highly sensitive to abnormalities in blood vessels, including aneurysms, stenosis (narrowing), and arteriovenous malformations (AVMs).

Aneurysms: An aneurysm is a localized, abnormal blood vessel dilation that can occur in arteries or veins. An MRA is highly sensitive to detecting aneurysms, providing detailed images that allow healthcare professionals to assess the size, shape, and location. This information is crucial for determining the risk of rupture and guiding treatment decisions.

Stenosis: Stenosis is an abnormal blood vessel narrowing, which usually restricts blood flow. An MRA's high sensitivity enables the identification and precise measurement of stenotic areas. This is particularly important in conditions such as atherosclerosis and renal artery stenosis, where the narrowing of arteries leads to a reduced blood supply to vital organs.

Arteriovenous malformations (AVMs): These are abnormal tangles of blood vessels that can disrupt the regular blood flow pattern between arteries and veins. An MRA scan excels at examining AVMs as it creates detailed images that contribute to understanding the complex blood flow dynamics within these malformations.

Post-intervention evaluation: After vascular interventions, such as the placement of stents or surgical procedures, MRA's dynamic imaging helps assess the success of the intervention. It allows for visualizing blood flow changes, ensuring the vascular intervention achieves the desired outcomes.

Peripheral vascular disease: MRA enables clear visualization of blood flow in the arteries of the extremities. This helps diagnose PVD and peripheral artery disease (PAD), determine the extent of arterial narrowing, and guide treatment decisions, including interventions to improve blood circulation. MRA can also help diagnose blood clots.

Intracranial Blood Vessel Diseases

MRA's application in visualizing blood vessels within the brain is essential for understanding conditions like cerebral aneurysms and vascular malformations.

Identification of cerebral aneurysms: An MRA plays a major role in identifying and defining cerebral aneurysms within the intracranial blood vessels. This information assists neurologists and neurosurgeons in assessing the risk of rupture and determining critical treatment strategies.

Visualization of other vascular malformations: MRA's detailed imaging capabilities extend to visualizing vascular malformations within the brain. This includes arteriovenous malformations (AVMs) and providing critical treatment planning and management information.

What’s the Difference Between an MRA and a CTA?

The main distinction between magnetic resonance angiography and computed tomography angiography (CTA) is similar to the difference between an MRI vs CT scan. Except here, we are discussing two medical imaging techniques used to visualize blood vessels within the body. 

While they serve a similar purpose, there are key differences in technology, contrast agents, ionizing radiation exposure, and the information they provide. Below are some of the key differences.

Technology: CTA is a CT scan utilizing X-ray technology and computer processing to generate cross-sectional images of blood vessels. It involves ionizing radiation, which may cause cellular damage and increase the risk of cancer over time. 

Contrast agents: Iodine-based contrast dye given during a CTA or intravenous contrast material like gadolinium given during a MRI to better highlight the blood vessels.

Diagnostic use: CTA is versatile and widely used for imaging blood vessels in various parts of the body. It’s frequently employed for assessing vascular diseases, including coronary artery disease, pulmonary embolism, and peripheral artery disease.

An MRA might be preferable for those who need to avoid ionizing radiation. Otherwise, a CTA may be chosen when doctors need to image an area rapidly, and the patient has a a history of an allergic reaction to gadolinium-based contrast agents.

Choose the Power of Proactive Cancer Screening With a Full-Body MRI

So far, we’ve discussed MRA vs MRI uses in diagnostic imaging. However, there is another area where MRIs stand out as a preferred imaging test: whole-body imaging. 

As a screening method for diseases like cancer, whole-body MRI scans are cutting-edge. Ezra is a leader in this approach. The Ezra full-body screening MRI takes detailed images of multiple organs and tissues across the entire body simultaneously in less than an hour.

The Ezra Full Body MRI is designed to detect changes before symptoms even arise. Early detection enables doctors to intervene at a stage when conditions are likely more manageable, potentially preventing the progression of diseases.

Ezra offers the convenience of an annual screening, establishing a regular and consistent monitoring routine. This frequency helps ensures that changes or developments within the body are promptly identified, allowing for timely intervention.

How Do You Decide Between Imaging Methods?

MRA vs MRI: patient talking to her doctor online

Fortunately, your doctor’s expertise will guide the decision when considering an MRA vs MRI. These advanced imaging techniques provide invaluable insights into various aspects of your health, allowing for precise diagnosis and targeted treatment planning. 

Whether assessing blood vessels with MRA or obtaining detailed images of soft tissues with MRI, the choice is guided by your specific medical needs. As technology advances, the collaborative decision-making process between you and your healthcare provider ensures you receive the most effective and tailored imaging approach. 

For booking an elective MRI screening, Ezra has you covered. The Full Body Scan uses advanced 3T MRI technology to create detailed images of up to 13 organs and body parts. With insights from your scan, you and your primary care provider can make informed decisions together, guiding further testing and lifestyle adjustments. This collaborative and proactive approach empowers you to actively manage your health. 

The best part? You can kick start this journey today by booking online in less than 10 minutes.