Physics has played a critical role in the development and advancement of medical imaging technologies. Prior to the 1800s, a lot of the information about the internal body organs was learned by actually viewing the inside of the body. The information obtained was used to create drawings and illustrations that were later used by physicians. During the late 1800s, the understanding of physics led to the development of radiation that helped see inside the body. It is during this time that Magnetic Resonance Imaging (MRI) scanners were developed. The machines, which use X-rays have been used over the years to not only diagnose various diseases but also to take images of broken bones. Today, MRI scanners produce images that are much more detailed and that are of higher quality. In this paper, I will describe how physics is used in the radiology profession.
The human body is made up of billions of atoms. Once a patient slides into the MRI machine, they take with them these atoms. It is also important to note that a significant part of the human body is made up of water. Also, water contains hydrogen atoms. For the purposes of an MRI scan, the hydrogen atoms are of great significance. The atoms in the body are always spinning and moving randomly in all directions. However, when they are subjected to an MRI machine, they align in one direction, the direction of the magnetic field.
The hydrogen atoms produce a strong magnetic moment, which is the orientation and position of the atoms. The MRI’s magnetic field runs down the center of the scanner. As such, the hydrogen atoms line up in such a way that they point to either the patient’s head or feet. This lining up is sufficient to create extremely detailed images of the inside of human bodies. Another thing that goes on during the scan is the application of a radio frequency (RF) pulse, which is specific to the hydrogen atoms. The MRI system then directs the pulse towards the area that the radiologist wants to examine.
The MRI system is able to pick any point inside the patient’s body for examination. The system goes through the body point by point while creating a map of all the tissues. The computer system in the MRI machine then integrates all the information to create either 2-D or 3-D images. The images are so detailed that the radiologists are able to visualize various body tissue abnormalities just by looking at the pictures. Normally, a letter ‘A’ is given for normal tissues and a ‘B’ is given for tissues that depict abnormalities.
In conclusion, radiologists use MRI machines to see the inside of human bodies and construct an image for use by other physicians. While the physics concepts used in the machines are complex, they are part of a branch of physics called quantum physics, which deals with much smaller things such as atoms and electrons. Since MRI machines deal with hydrogen nuclei, they follow the rules of quantum physics. The machines were specially designed to take advantage of specific principles of physics, such as water molecules, hydrogen atoms, protons, and how they react once subjected to a strong magnetic field. Radio-frequency coils inside the scanner then pick up this information and transmit it to a computer where an image is generated. The machines provide a non-invasive way for radiologists to diagnose medical conditions, from tumors to torn ligaments. In the recent past, MRIs have been essential in examination of the spinal cord and the brain.