—— “Vegan doesn’t automatically mean natural.” Dr. Andreas Daxenberger, Food Auditor at TÜV SÜD, explains the testing of the International Food Standard.
MRI is an acronym for magnetic resonance imaging, a medical imaging technique that makes it possible to create layer-by-layer images of the human body. MRI is used for examinations of what are known as soft tissues, which can include the brain, breasts or kidneys. Doctors can also look at joints or spinal disks, for instance in cases when they suspect the patient might have a herniated disk. Unlike other imaging methods, such as X rays, MRI doesn’t use radiation to create images.
An adult’s body consists of about 60 percent water. These water molecules contain hydrogen protons that rotate around their own axes, meaning they have a measurable “spin.” As long as they aren’t subject to some external magnetic source, these numerous subatomic particles move around in a completely random manner, pointing in completely different directions as they continue spinning.
The MRI scanner generates a strong external magnetic field. As a result, all the protons align themselves along this magnetic field, either in the same direction, or in the exact opposite direction. To put it simply, imagining the protons as passengers on a train: they are all facing either in the direction the train is going or they are facing backwards, but they aren’t facing up, down, or to either side.
In the second step, a high-frequency pulse of energy is sent through the person’s body, what is known as a radio frequency impulse. This is generated by magnetic coils inside the MRI scanner. This pulse causes some of the protons to absorb the energy and tip to one side, in a manner of speaking.
As the energy pulse is turned off, the protons then realign themselves with the initial magnetic field. This realignment causes the protons to emit a small amount of energy in the form of high-frequency signals, which are then crucial for the final step.
An antenna captures these signals, which are then compiled by a computer to form an image for the attending doctor. In this way, a layer-by-layer image of the person is created, according to the part of the body and its composition.