Spoiler Alert: You May Never Look at the World the Same Way Again
I am going to let you in on a huge secret that you may not have heard before. Are you ready? Now, take a really close look at the corner of the computer monitor on which you are reading this article… can you see it vibrating? And if you are reading a printed copy of this article, that paper too… it’s vibrating. And so is the ink in every letter on that paper. In fact, every cell in your hand is vibrating right now. Right and left hands both, all the way from the hair on the surface down to the DNA inside every muscle cell.
Look around you… Every single plant, piece of furniture, and piece of architecture that you see around you is made up of physical atoms that are constantly spinning and vibrating on a submicroscopic level, each with their own unique energy signature. The concept that every structure we take to be "solid" is actually made of energy and vibrations is the basis of an entire field of research called quantum physics.
And while quantum physics is fascinating, it also falls outside of the scope we have reserved for this very brief article, designed to be read over a single cup of coffee.
Alan Alper Sag, MD, is an American Board Certified Diagnostic Radiologist with Certificate of Additional Qualification in Interventional Radiology by the American Board of Radiology. He specializes in Interventional Oncology (minimally-invasive targeted cancer therapies) and trained at Memorial Sloan Kettering Cancer Center and Weill Cornell New York Presbyterian Hospital in Manhattan, New York. His clinical and research interests include minimally-invasive tumor embolization, tumor ablation, and medical education. He lives in Istanbul and is a faculty member at Koc University School of Medicine.
So instead, I would like to pose this question to you: What if I told you I had a machine that could nearly pause these vibrations in the human body? And instead of pausing all the physical atoms, perhaps we could focus on Hydrogen, which constitutes 10% of the elemental abundance in the human body (after Oxygen at 65% and Carbon at 18%) and occurs in every type of body tissue. Then, what if we used this machine to align all the hydrogen spins, and pause them? Would it hurt? Would it tickle? Would it affect the DNA? Would it be reversible? What would happen then if we let the spins loose? Would they always know to go back to their original spinning speed and direction?
Actually, this device is called an MRI (magnetic resonance imaging machine). We use these every day to look into the human body and make life-saving diagnoses. But how can we use a machine that deals with atom vibrations to look into the human body you ask? Since most of us or our loved ones will probably have an MRI at some point, I would like to take explain how MRI works in four quick points (which will be a vast simplification on a topic which populates volumes of textbooks):
- Point #1: The human body contains 4.7 x 1027 (that’s a lot of zeroes) hydrogen atoms, each living in their own comfortable little environment, such as bone, fat (all of us have some), muscle (some of us wish we had more), or fluid (such as blood which is moving in a hurry, or cerebrospinal fluid which is moving very slowly).
Point #2: Remember how everything always vibrates? At “rest”, every hydrogen atom is vibrating in a spin and direction called the “Larmor frequency". If you bend a hydrogen atom away, it will do everything it can to get back to its resting state.
Point #3: An MRI machine bathes the patient in a magnetic field that is 30,000-60,000 times stronger than the earth's gravitational pull (comparing a 1.5 Tesla – 3.0 Tesla magnet to the Earth's 0.5 gauss magnetic field). This magnet is so strong that it tricks the hydrogens into orienting their rest positions toward a single unified direction. Then, just as the hydrogens are getting comfortable in their new resting positions, the MRI machine “bullies” the hydrogens by giving them a “push” via an extra magnetic “pulse” to bend the hydrogens away from rest. (This last part is what creates the noise you hear during an MRI scan, by the way).
Point #4: Remember how all hydrogens just want to get back to their resting state? When that extra magnetic “pulse” turns off, the hydrogens begin relaxing back to their resting state. But here is the trick: they relax at different speeds based on the tissue in which they reside. And in the process, they give off energy that we can measure, to create a map of the different tissues, and therefore a medical image inside the human body.
This representative image shows the relation of a deep tumor (purple structure next to the arrow) to the major neuron tracts (shown in yellow). This information is valuable for safe treatment planning. Image obtained from UCLA webpage at http://neurosurgery.ucla.edu/body.cfm?id=409, last accessed August 10, 2015.
MRI has proved its worth throughout the body, but one place that it shines is in the diagnosis of brain diseases. MRI can not only detect and help diagnose brain tumors, but it can create maps of nerve pathways that the tumor is pushing or invading, detect the blood supply to the tumor and map the regional blood vessels, and even help follow-up after surgery or radiation treatment to make sure there is no tumor recurrence. All of this with no radiation dose to the patient. The future for MRI is bright in medicine and even outside of medicine. For example, some researchers are attempting to use MRI as a lie detector machine, scanning the brain as patients answer questions. Whether these applications will become useful in the future remains open to discussion. But what is known is that MRI has made sweeping and permanent changes to the way that medicine is practiced in this century.