Do you ever wonder how physics could possibly be used in the world of biology? After all, the two studies of science vastly differ from each other, don’t they? Physics deals with the strange phenomena and forces that dictate how matter behaves in the universe. Biology, on the other hand, deals with understanding everything to do with life. However, despite their differences, there is a study of science where the knowledge and understanding of physics can be incorporated into biology.
Written by Brian Li
Medical physics is a branch of applied science in which physicists contribute their work in the medical field. Some of the work you usually hear medical physicists conduct involves working with X-rays, magnetic resonance imaging (MRI), ultrasound, and many more (“What is Medical Physics?”). This means that most medical physicists are usually tasked with providing information to help doctors with their diagnoses, treating diseases such as cancer, providing safety measures against ionizing radiation, or conducting research to advance the medical field (“Medical Physics”).
But how does medical physics combine both physics and biology? If we look at two different applications of work listed above (X-rays and MRI), we can see a glimpse at how a medical physicist applies both subjects of science.
1) X-rays
X-rays apply the knowledge of electromagnetic waves and density of physics to the human body to create X-ray scans. X-rays are a type of electromagnetic radiation that are not visible to the human eye and can easily pass through tissues found in the human body (“X-rays”). When working with X-ray scans, the different parts of the body like muscle and bones absorb different amounts of X-rays due to their radiological density (“X-rays”). The higher the density, the greater the amount of X-rays that will be absorbed by the substance. Medical physicists utilizes their understanding of physics with electromagnetic waves to generate an image. To distinguish the different body parts shown in the x-ray images, the physicists would also need to understand the anatomy of the human body, showing their knowledge in biology.
2) Magnetic Resonance Imaging (MRI)
MRI uses the knowledge of magnetic forces in physics and applies it to the human body to generate images. An MRI utilizes protons, magnetic forces, and radiofrequency currents to generate clear images of body parts. A magnetic field is created by magnets to force protons in the body to spin in alignment with the magnetic field (“Magnetic Resonance Imaging (MRI)”). A radiofrequency current is then used to force the protons to spin in the direction opposite to the magnetic field. When the radiofrequency current is turned off, the protons will realign with the magnetic field and emit energy (“Magnetic Resonance Imaging (MRI)”). This energy is then detected by a sensor which generates an image. Different substances will emit different amounts of energy and the time it takes for the protons to realign with the magnetic field varies (“Magnetic Resonance Imaging (MRI)”). This allows for an image to be created and physicians can analyze the different types of tissue in the image based on the magnetic properties explained.
Works Cited
“Magnetic Resonance Imaging (MRI).” National Institute of Biomedical Imaging and Bioengineering, U.S. Department of Health and Human Services, www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri.
“Medical Physics.” International Organization for Medical Physics, www.iomp.org/medical-physics/.
“What Is Medical Physics?” COMP / OCPM, comp-ocpm.ca/english/about-comp/what-is-medical-physics/what-is-medical-physics.html.
“X-Rays.” National Institute of Biomedical Imaging and Bioengineering, U.S. Department of Health and Human Services, www.nibib.nih.gov/science-education/science-topics/x-rays.