MRA Benefits v Risks

  • MRA is a non-invasive imaging technique that does not involve exposure to ionizing radiation.
  • Detailed images of many blood vessels and blood flow can be obtained without having to insert an IV catheter into the blood vessels. However imaging of certain regions of the body such as the aorta and limbs require intravenous dye. 
  • MRA procedure time may be shorter than a traditional catheter angiography and requires no recovery period. You may return to your normal daily activities immediately following the MRA examination.
  • MRA is less costly than catheter angiography.
  • MRA can provide useful high-quality images of many blood vessels, even without using a contrast material.  This makes it very valuable for patients prone to allergic reactions or with reduced kidney or liver function.
  • The contrast material used in MRI exams is less likely to produce an allergic reaction than the iodine-based contrast materials used for conventional x-rays and CT scanning.
  • The MRI examination poses almost no risk to the average patient when appropriate safety guidelines are followed.
  • If sedation is used, there are risks of excessive sedation. However, the Technologist or Nurse monitors your vital signs to minimize this risk.
  • Although the strong magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems during an MRI examination.
  • Nephrogenic Systemic Fibrosis is currently a recognized, but rare, complication of MRI believed to be caused by the injection of high doses of gadolinium-based contrast material in patients with very poor kidney function. Careful assessment of kidney function before considering a contrast injection minimizes the risk of this very rare complication.
  • There is a very slight risk of an allergic reaction if contrast material is injected. Such reactions usually are mild and easily controlled by medication. If you do experience symptoms of an allergic reaction, a Radiologist or other Physician will be available for immediate assistance.    
  • Unlike CT angiography, MRA is not able to see and capture images of calcium deposits within the blood vessels.
  • The clarity of MRA images of some arteries does not match those obtained with conventional catheter-based angiography. MRA evaluation of small vessels, in particular, may be difficult. Sometimes it may be difficult to create separate images of arteries and veins with MRA.
  • Individuals who have difficulty remaining still or lying on their back may have MRA images that are of poor quality. Some tests involve monitoring the heart beat or require patients to hold their breath for 15 to 25 seconds at a time in order to get high quality MRA pictures. Any type of motion, such as patient movement, breathing motion, or other involuntary movements can significantly decrease the image quality and potentially limit diagnosis.
  • High-quality images are assured only if you are able to remain perfectly still and follow breath-holding instructions while the images are being recorded. If you are anxious, confused or in severe pain, you may find it difficult to lie still during imaging.
  • A person who is very large may not fit into the opening of certain types of MRI machines.
  • The presence of an implant or other metallic object sometimes makes it difficult to obtain clear images. Patient movement can have the same effect.
  • A very irregular heartbeat may affect the quality of images obtained using techniques that time the imaging based on the electrical activity of the heart, such as electrocardiography (ECG).