MRI and CT scans are now almost part of the popular language. We speak a bit quickly of “radio” … While they are in fact two very different techniques which are part of what is called today “medical imaging”.
Since 2012, radiologists have been celebrating International Radiology Day on November 8… With the idea of better highlighting the role of imaging in modern medicine. The choice of this date owes nothing to chance since it was on November 8, 1895 that Wilhelm Conrad Röntgen discovered the existence of X-rays.
Staggering progress
Imagine that science could revive Röntgen for a few minutes in front of the screen of a nuclear magnetic resonance device or a scanner and ask him what year it is. I am convinced that he will believe himself centuries ahead; just like a doctor of the fifties who could not believe that the scene takes place a few decades from the time when he was practicing with the help of a stethoscope, x-rays and above all by his common sense.
CT scans and Magnetic Resonance Imaging are now familiar – even required – examinations by the patient. Often confused, however, it is a question of extremely different techniques, and especially of the future, diametrically opposed. One is heir to the past and to X-rays. The scanner is, in fact, the great-grandchild of Pierre and Marie Curie, the final step, undoubtedly the most successful of the X-ray. It is now possible to make very fine, millimeter sections to see very small tumors and it is also possible to make 3D reconstructions.
On the other hand, Magnetic Resonance Imaging is the first practical translation of a new technique that uses the resonance of the hydrogen atoms in our cells, hence its name! Its principle is simple. A gigantic magnet makes our hydrogen atoms vibrate and this vibration is recorded, analyzed by computer and the machine draws up a cartography – in color and in relief – of the density of these hydrogen atoms.
MRI does not use x-rays
As hydrogen is everywhere, we can therefore see everywhere, even where the scanner gives blurry images, that is to say in everything that is soft in our body: muscles, liver, brain, but also the heart and kidneys. The fields of use are therefore more and more numerous. Especially since the exam, which lasts on average half an hour, does not require any special preparation.
After getting rid of all the metal accessories (watch or belt that we would quickly find stuck in the magnet), the patient, lying on a rolling table, is introduced into a sort of airlock where he must remain motionless during the ‘exam. The only downside at this point is for the claustrophobic who should be warned about the somewhat “sarcophagus” aspect of the whole.
When it comes to children who cannot stay still, rapid anesthesia may be used. Apart from that, MRI is completely painless and can even be used in pregnant women because, another advantage compared to the scanner, it does not expose the patient to radiation. Obviously, it is formally contraindicated to all those who have metal prostheses in their body: pacemaker, total hip prosthesis or insulin pump.
Seeing inside the body with incredibly sharp images, science fiction has been joined by science itself. And, I was telling you a moment ago, we’re just getting started. There are 2 drawbacks to MRI. First of all, its price. MRI remains expensive and should therefore only be used wisely for now. Second, the insufficient number of MRIs in France, with sometimes too long access times in certain regions.
http://www.journee-mondiale.com/388/journee-internationale-de-la-radiologie.htm
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