What is the difference between Ultrasound and MRI?

Ultrasound and Magnetic Resonance Imaging (MRI) are two different devices in medicine for detecting the right diagnosis for patients. MRI works in such a way that it aligns molecules inside the human body with the help of magnetic fields, then it scans the orientation of change in molecules per time. An ultrasound creates visual representation after a bounce back from the sound waves produced by it. Comparing the two devices together, MRI is big and bulky because it is made of a large amount of magnet. It is more costly and rare in hospitals.

This is not so for ultrasound, as ultrasound is a very portable and simple device. It is quite cheap to acquire and more common than the latter. MRI produces a three-dimensional view of the scanned image, while ultrasound gives the view the way it is. Ultrasound is mostly known for being used to view a fetus, to view the baby inside a pregnant woman.