There is a strong link between medical imaging and physics, because most imaging techniques require advanced scientific knowledge. Ultrasound machines, for example, could not have been invented without a detailed understanding of the properties of high-frequency sound. Nuclear imaging and magnetic resonance imaging (MRI) scans also require a deep knowledge of how different materials react in various situations, such as under the influence of a strong magnetic field.
Many medical imaging techniques could only have been developed once a particular technology was well understood, which is why medical imaging and physics are so closely linked. Scientific research has resulted in greater knowledge of high-energy electromagnetic waves, strong magnetic fields and ultrasound. This basic research has allowed medical physicists to research and develop medical applications for these natural phenomena. It also is essential for safety reasons that a lot is known about a particular type of technology, such as strong magnetic fields for MRI scans, before they are used in medical situations.
Ultrasound is one example of how medical imaging and physics are strongly linked. To perform an ultrasound scan, a machine is used to create high-frequency sound. This sound is too high for a human to hear but, thanks to scientific research, a lot is known about how it reacts to different materials. The benefit of ultrasound is that it can penetrate and reflect off material, which allows an internal image of the body to be created. There are many other medical applications for ultrasound machines, including breaking up kidney stones and treating sports injuries.
Nuclear medicine is one of the best examples of the link between medical imaging and physics. Over the past century, a huge amount of research has been performed on radioactive substances. This means scientists have a large amount of knowledge about how various radioactive substances react in different situations. Nuclear medicine scans use the well-established decay rate of radioactive materials, which can be predicted very accurately as long as the substance is found in reasonable quantities, to form a detailed image of the body. Scientific knowledge of how radioactive materials decay also sets limits on the amount that’s safe for human exposure.
MRI scans also demonstrate the link between medical imaging and physics. An MRI scanner uses magnetic fields that are up to 30,000 times the strength of the Earth’s magnetic field to affect the atomic spin of atoms in the body. This type of scan combines scientific knowledge of magnetic fields, electromagnetic waves and quantum mechanics to create a highly detailed image. Scans such as this would not be possible without a huge amount of research into many areas of physics.