From the Guidelines
MRA, or Magnetic Resonance Angiography, is a non-invasive medical imaging technique used in radiology to visualize the blood vessels and diagnose vascular conditions.
Key Characteristics of MRA
- It uses a strong magnetic field and radio waves to produce detailed images of the blood vessels, without the need for contrast agents containing iodine, which are commonly used in traditional angiography 1.
- MRA is commonly used to evaluate conditions such as stenosis, aneurysms, and vascular malformations in various parts of the body, including the brain, neck, and legs.
- The procedure typically involves administering a gadolinium-based contrast agent, such as gadopentetate dimeglumine, at a dose of 0.1-0.2 mmol/kg, to enhance the visibility of the blood vessels 1.
- The entire procedure usually takes around 30-60 minutes to complete.
Advantages and Limitations of MRA
- MRA has high sensitivity and specificity for detecting arterial occlusive disease, with values ranging from 90% to 100% 1.
- It is a non-invasive procedure, which reduces the risk of complications and makes it a safer alternative to traditional angiography.
- However, MRA may not be suitable for patients with claustrophobia, pacemakers, or metal implants, and may not provide accurate images in patients with severe renal failure 1.
- MRA may also overestimate stenosis in some cases, and may not be able to detect smaller arteries or arterial calcifications 1.
From the FDA Drug Label
Magnetic Resonance Angiography (MRA) of Renal and Aorto-ilio-femoral Vessels MultiHance is indicated for use in magnetic resonance angiography (MRA) to evaluate adults with known or suspected renal or aorto-ilio-femoral occlusive vascular disease.
Magnetic Resonance Angiography (MRA) is a medical imaging technique used to evaluate adults with known or suspected renal or aorto-ilio-femoral occlusive vascular disease. It is used to visualize the blood vessels and diagnose conditions such as stenosis or occlusion.
- Key points:
- MRA is used to evaluate renal and aorto-ilio-femoral vessels
- It is indicated for adults with known or suspected occlusive vascular disease
- The technique uses a contrast agent, such as gadopentetate dimeglumine, to enhance the visibility of the blood vessels 2
From the Research
Definition and Principles of Magnetic Resonance Angiography (MRA)
- Magnetic Resonance Angiography (MRA) is a non-invasive procedure for evaluating the vascular system, relying on the specific signal alteration determined by flowing blood 3.
- The basis of MRA is to obtain images of vessels from Magnetic Resonance (MR) data, using special techniques to evidence signals from flowing blood while cancelling signals from surrounding stationary tissues 3.
Clinical Applications of MRA
- MRA has various clinical applications, including:
- Evaluation of intracranial vessels, providing important adjunct information to conventional MR images 3.
- Definition of cerebrovascular disease, including the carotid artery, with good correlation with Digital Subtraction Angiography (DSA) 3.
- Evidence of abdominal vessels, with clear imaging of abdominal aortic aneurysms 3.
- Definition of renal arteries, potentially useful in the future for screening renovascular hypertension 3.
- Visualization of peripheral vessels, with potential application in evaluating peripheral run-off distal to occlusions 3.
Comparison with Other Imaging Techniques
- MRA is compared with conventional imaging techniques such as Doppler ultrasound and angiography, highlighting its role in vascular surgery 4.
- MRA can be used in conjunction with other vascular imaging techniques for investigating and managing carotid disease, aortic disease, and peripheral vascular disease 4.
Techniques and Considerations
- Various MRA sequence options are available, each with strengths and weaknesses, and understanding these techniques is essential for recognizing common imaging issues and artifacts 5.
- The physics behind MRA contributes to the general understanding and interpretation of anatomic images, and magnetic resonance techniques drive clinical decision-making by vascular physicians 6.
- MRA techniques can be divided into two main classifications: time-of-flight (TOF) and phase contrast (PC) methods, each with particular advantages and limitations 7.