Ultrasound or MRI?

If you are in need of medical imaging, you might be wondering if an ultrasound or MRI is right for you. Read on to discover the differences between the two and why, in many cases, high resolution ultrasound has a big advantage over MRIs.

How They Work

An ultrasound works by using high-frequency sound waves. These sound waves, which cannot be heard by the human ear, are sent into the body by a transducer. The waves bounce off the body’s tissues creating echoes that are also picked up and read by the transducer, forming images of organs and soft tissues.

An MRI uses magnets and radio waves to create detailed images of the inside of the body. The magnets cause protons in the body to align the direction in which they spin. The magnetic field is turned off and the process of the protons returning to their original spin direction gives off a radio signal that can be read by the MRI.

Both MRIs and ultrasounds are painless and safe, making them a popular choice for both doctors and patients.

The Ultrasound Advantage

While both MRIs and ultrasounds generate images, the ultrasound has many advantages including:

  • Ultrasounds are much less expensive than MRIs. This is especially important for patients who have no insurance and who must pay out of pocket for medical expenses.
  • The equipment required to perform an ultrasound doesn’t take up much space so a patient can have an ultrasound right in the same exam room where they are having their doctor’s appointment. This also means a patient can have an ultrasound performed on the spot and get a diagnosis the same day, whereas with an MRI, the appointment would have to be scheduled for another day.
  • During an MRI, a patient has to keep completely still. Unfortunately, there are many conditions/injuries that cannot be readily detected by imaging equipment unless the injured part of the body is in motion. Ultrasound can be used to observe muscles and other tissues while they are in motion.

Which One to Choose?

Ultrasounds and MRIs can both be used for a wide variety of imaging needs; however, there are some things that are better viewed by each. For instance, MRIs are better for viewing the spinal column and the brain while ultrasounds are used for viewing developing fetuses and the heart. However, always speak with your doctor about choosing the imaging scan that’s right for you.