Imaging

What’s that knocking?

MRI technology is one of the great achievements of medical technology - discover 12 things that are barely known. 

6 min
Philipp Grätzel von Grätz
Published on 26. November 2020

Magnetic resonance imaging (MRI) has been part of routine medical practice for years. The big tubes produce fascinating images. No wonder that MRI is seen as the crowning glory of diagnostics. But how exactly does it work? What’s so special about it? We answer twelve questions to give a better idea.


MRI imaging brain
Major fields of application of MRI include visualizing the brain, inflammation, cancer, muscles and joints, blood vessels and the heart.
When you place a person in the extremely strong magnetic field of an MRI machine, hydrogen nuclei with their mini magnetic fields align with the MRI´s magnetic fields and spin in step.
An MRI is structured like a Russian doll: the superconducting magnetic coil is placed on the very outside of the MRI machine. Then come the gradient coils. And on the inside are the body coils.
A 3-tesla MRI machine produces a magnetic field around sixty thousand times stronger than the earth’s.
With the magnetic coils, the cooling system, and all the equipment required to stabilize the machine, a scanner ends up weighing between six and seven tons.
MRI scanners certainly make plenty of noise. Depending on the machine and the sequence used, the noise can easily reach aircraft volume levels.

By Philipp Grätzel von Grätz

Philipp Grätzel von Grätz lives and works as a freelance medical journalist in Berlin. His specialties are digitalization, technology, and cardiovascular therapy.