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MRI Vs. MRA: The Subtle Differences You May Not Know

MRA and MRI are diagnosing techniques and are directed towards the detection of different problems. Let us take a deeper look into the difference, similarities and most importantly, the purpose of these two imaging techniques.
Shah Newaz Alam
Last Updated: Mar 12, 2018
Of the many scientific breakthroughs in the last century, one of the most fascinating discoveries is the ability to view the internal structure of an object, without penetrating it physically. Imaging allows intimate details of a body to be displayed, without actually disturbing the structure in any way. In the arena of medicine, its use is very beneficial, as internal diseases and ailments of the body can be depicted in images. This form of imaging in the field of medicine, is called radiology. There are various imaging techniques used in radiology. One of the oldest and most well-known is radiography or using x-rays to form an image. Other techniques using x-rays, are fluoroscopy and computed axial tomography (CT scanning). But there are two imaging techniques used today, that do not involve x-ray radiation at all. They are MRI and MRA.
Differences and Similarities Between MRI and MRA

Full Form
Magnetic Resonance Imaging Magnetic Resonance Angiography
Type of Technique
Radiology Radiology
Scientific Property
Nuclear magnetic resonance Nuclear magnetic resonance
Scientific Elements
Magnetism and radio waves Magnetism and radio waves
Images Formed
2D and 3D images Mainly 3D but 2D images can be generated
Basic Working
A magnetic field is created around the body. Due to this, the hydrogen atoms in the body align themselves. Then the machine emits radio waves, which agitate the atoms in the body. The protons in these atoms, spin and emit energy, creating a different radio signal. This signal is picked up by the MRI's receiver, which passes it to a scanner, that generates an image. Same as MRI. A nearly identical machine is used. Sometimes a particular liquid or substance like gadolinium, is injected into the patient, to enhance the quality of the generated image. Such substances are called contrast agents.
Is It Non-Invasive?
Yes Yes
Medical Areas of Use
Can be used to define soft tissue areas of the body like the brain, heart, muscles, blood vessels and joints. It can also detect tumors, aneurysms and nerve injury. It is used to provided detailed and intricate imaging of blood vessels and their functioning in different parts of the body. It can also assess blood flow and circulation.
Duration of Scan
20 minutes to 2 hours 15-90 minutes
Is Radiation Used?
No No
How is it Similar to an X-ray?
It is non-invasive and painless Same as MRI
How is it Different from an X-ray?
No side effects are caused and no ionizing radiation is used. Same as MRI
How is the Generated Image Different from an X-ray?
X-rays can only highlight a bone's form, they cannot define it or provided a view of the flesh within. Same as MRI
Cost of Procedure
Depending on the body area being scanned and the scanning center, price range is between $300-$5000 approx. $600-$1000 approx
Side Effects
No known side effects or risks No known side effects or risks
Who Should Not Undergo This Procedure?
Those with metal implants like inner ear implants, dental fillings or pacemakers; Those with shrapnel or bullet fragments; pregnant women; those with metal joints, prosthetic limbs or metallic plates in their bodies; patients with artificial heart valves or insulin pumps.
Those with medical and cosmetic metallic implants like braces, pins or plates; heart patients or patients with blood disorders, who may have stents, pacemakers, valves or infusion pumps; pregnant women; women who have IUDs (intrauterine device)

In summation, both MRI and MRA are actually very similar in principle and technique. The actual difference between them, is in the generated image. Hopefully the above tabular comparison is useful in highlighting the key points and features in these radiology techniques.