Ultrasound and MRI (Magnetic Resonance Imaging) are two devices in medicine that are used to provide patients with a valid diagnosis. MRI uses magnetic fields to align molecules inside our bodies and scans the rates at which these molecules changes its orientation. And from that, it can create an image that represents how it looks inside. An ultrasound sends sound waves into the body and listens for the sound waves that are bounced back. It can then create a visual representation from that. If you look at it closely, it operates just like a sonar does.
When it comes to the equipment, there is quite a big difference between the two. An MRI is rather big and bulky due to the very large magnet that is needed. It’s cost is also quite high and this is the reason why it is not available in some hospitals. An ultrasound is a very simple and small device. It is small enough to fit on a small table while some units are packaged into portable units to be carried around.
MRI creates static cross-sectional images of the body which can combined to create a three dimensional view. Unlike MRI, an ultrasound creates a real-time moving image of what you are looking at. The most common use of the ultrasound is for looking at a fetus inside a pregnant woman where both the mother and the doctor can look and inspect how the baby is doing.
Using ultrasound to scan areas that has air or bone becomes very problematic. That’s why it can’t examine the lung closely as the air inside interferes with the sound waves. This is not a problem with MRI.
Ultrasound is the most used of the two as the cost and complexity of MRIs makes it quite difficult for most people to take advantage of. Even veterinarians use ultrasound on animals who are pregnant.
Summary:
1.MRI uses magnetic fields to look inside the body while Ultrasound uses the reflected sound
2.The MRI machine is huge and very expensive while an ultrasound machine is small and cheap
3.With MRI, you get a static picture while ultrasound presents you with a real-time moving view
4.An ultrasound cannot view through bone or air while that is no problem with MRI