Biomedical Imaging Machines
The different prominent medical diagnostic machines classified by the consortium of boards and organizations of the USA under the banner of Mathematics and Physics of Emerging Biomedical Imaging are listed below. We will remain confined more to Physics instead of Mathematics as the objective is to make one understand how Physics plays its role in these machines.
3. X-ray Computed Tomography (CT)
4. Magnetic Resonance Imaging (MRI)
5. Positron emission tomography (PET)
6. Electrical source imaging (ESI)
7. Electrical Impedance tomography (EIT)
8. Magnetic source imaging (MSI)
9. Medical optical imaging (MOI)
10. Single photon emission computed tomography (SPECT)
Except for the first which is based on Sound waves, all of the remaining machines use the Electro-Magnetic signals and waves (EMW) intercepted from the patients’ body then convert them into images. In my subsequent blog on wave motion, the difference will be dealt with and explained between the two types of waves used by these two classes of diagnostic machines.
All above forms of respective procedures, in the end, give out a series of images. The reports are then prepared by comparing the images obtained of the patient under investigation by the experts based on the criteria and values set up/built on standard images obtained from normal human beings of the same age, sex, and having the same BSA (body surface area) as of the patient. That analysis determines what is the state of health of the patient and what course of treatment needs to be followed for patients’ recovery by the dealing physicians.
There is one more machine that is based on EMW used in diagnosis by carrying out echocardiography (ECG) of the patients. Unlike other machines, the results obtained through this machine are not in the form of images but graphs using different electric probes placed on the body parts of the patient under investigation. These probes measure the electric signals captured from the patient’s body to prepare the graphs.
At the roots of all living organisms’ functioning (not limited to human bodies alone), lies the molecular and atomic structure of matter. That matter is composed of the elementary particles Electrons, Protons, and Neutrons, etc., and their interaction results in the creation of images that are captured by these machines. Remember, Electron is negatively charged and Proton is a positively charged particle. While Neutrons do not carry any charge on them.
Further, at the molecular level too, the existence of positive and negative ions move through the blood and are coming out of the structure of nutrients, proteins, enzymes, etc. It is this movement within the patient’s body structure that is captured to create images. The reason, according to the EM Theory, a moving charge creates an electric current and also a magnetic field.
All this will be dealt with by taking each machine at a time and understanding its functioning alone in a step-by-step manner.
April 01, 2021