Are radio waves in the longitudinal direction

Open vs. classic MRI machine

Special "open" MRT machines have been developed for patients with claustrophobia. The oppressive feeling should not be felt here. But why is it like that and how do the open and classic MRI machines still differ from each other?

Basic principle of the MRT machines

Magnetic resonance tomography makes use of the following basic principle: All atomic nuclei in the organism rotate around their own axis. This angular momentum is called "nuclear spin". The rotation of the nuclei creates a minimal magnetic field.

The hydrogen nuclei are important here. Under natural circumstances, the magnetic alignment of the hydrogen nuclei is purely coincidental. If, however, a magnetic field is applied from the outside, they all line up in the longitudinal direction of the body.

The MRT machine thus contains a magnetic field. In addition, coils are applied to the patient's body to increase the magnetic field. The MRT machine also emits high frequency radio waves (HF impulses) to the patient. This changes the alignment of the hydrogen nuclei in the body.

After each pulse, the hydrogen nuclei return to their original position before the position changes again. The atomic nuclei send out special signals. The computer measures these rays and then composes them into images.

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