MRI AORTIC ANGIOGRAPHY

Introduction 

MRI Aortic Angiography is known by the shorthand MRA of the Aorta, and it is an imaging technique that is non-invasive and can visualize the aorta and the principal arterial branches employing magnetic resonance imaging. It is performed with contrast (Gadolinium based agents) for better detailing of the blood vessels. The technique can also be helpful in diagnosing the presence of an aneurysm, dissection, stenosis, or any abnormal congenital change.  

What is MRI aortic angiography? 

An MRA test is a type of vascular investigation (also known as a vascular study) a patient has that generates 3D pictures of the aorta (substantially the blood vessel that channels blood from the heart) and its branches in astonishing detail utilizing powerful magnets and radio waves. Depending on the diagnosis and suitability of the patient, a contrast medium may or may not be used. 

• Overall aortic dimensions: ascending, arch, descending, and abdominal regions 
• Presence of any aneurysm or its constriction 
• Presence and extent of any dissection flap 
• Patency of the branch vessels: renal, iliac, subclavian, and carotid (ensuring there is no stenosis or occlusion) 
• Wall thickness including mural thrombus 

• Monitoring and early detection of suggestive life-threatening aortic pathology.  
• Monitoring known aneurysms for progressive growth. 
• Examining changes after endovascular repair (EVAR) has been done.  
• Evaluating chest pain when a dissection is on the list of possibilities.  
• Scheduling vascular/angioplasty surgery.  

When and Who Needs This Scan? 

Indications: 

• Thoracic or abdominal aortic aneurysm 
• Aortic dissection 
• Suspected coarctation (narrowing) of the aorta 
• Connective tissue disorders (e.g., Marfan syndrome, Ehlers-Danlos) 
• Trauma involving major vessels 
• Follow up on known aortic pathology or post-surgical repair 
• Screening with family history of aortic disease 

Patient Demographics: 

• Hypertensive adults and elderly or those with vascular risk factors 
• Patients with genetic disorders of the vascular connective tissue 
• Post-operative patients after aortic graft/stent placement 

Benefits of Taking the Test

• Absence of ionizing radiation.  
• Detailed cross-sectional and three-dimensional vascular images.  
• Numerous vascular segments can be imaged in a single scan.  
• High accuracy for dissection and aneurysms.  
• Use can be repeated safely.  

Conditions Diagnosed

• Thoracic and abdominal aortic aneurysms.  
• Aortic dissection (Stanford type A or B).  
• Aorto-iliac occlusive disease.  
• Congenital abnormalities, for example coarctation.  
• Mural thrombus or inflammation of the aorta (aortitis).  
• Surgical graft integrity.  

• No food intake for 4-6 hours (only water and clear beverages are allowed).  
• eGFR creatinine test (if contrast is to be used).  
• Dress in comfortable clothing with no metal zippers and accessories.  
• Notify the radiologist if pregnant/breastfeeding.  

Pre-requisites 

• Clinical history and indication.  
• Any earlier vascular imaging available (CT/US).  
• Renal function report if using contrast enhanced.  
• Cleared MRI safety checklist on file.  

Best time for the test 

• In the case of suspected aortic dissection, perform without delay.  
• Periodically during surveillance for aneurysms.  
• Before placing aortic or conducting vascular surgery stents.  
• In younger patients requiring radiation-free imaging.  

Eligibility 

• Candidates include individuals with an aortic disease diagnosis or with suspected aortic disease. 
• Not appropriate for patients with non-MRI compatible pacemakers, aneurysm clips or any other metal implants. 
• Severe renal impairment is a contraindication unless necessary. 

Procedure 

• Patient is placed in a supine position on MRI table. 
• Contrast agent is injected via a peripheral IV cannula (if needed). 
• Patients may be instructed to hold their breath during certain sequences. 
• Total imaging time is around 30 to 45 minutes on average. 
• If contrast has been administered, then the patient’s condition will be monitored. 

Cautions 

• Make sure the technician knows about any implants, stents or metallic fragments. 
• Patients suffering from claustrophobia may require sedatives. 
• Consuming water prior and after the scan aids in excreting the contrast agent.