What is Radiation ?
The science of Radiation is one of the important branches of physics. A radioactive material can emit radiation by losing energy in order to attain a more stable state. Such energy waves are called radiation and they are capable of passing through various mediums depending upon their type.
The science of applying various types of radiation in industrial and medical fields is known as Radiation Technology. More usage of radiation is prevalent in the medical industry than any other field. Radiation is used for both diagnostic and therapeutic purposes.
For example, using X ray to analyse a fractured bone is a diagnostic application of radiation technology. Usage of CT and MRI scans also fall under this category. Using radioactive materials to treat thyroid disorders and cancer forms the therapeutic part of radiation technology.
Uses of Radiation in medical diagnostics
The discovery and innovations in the field of radiation technology have travelled a long trajectory to serve the field of medicine. Diagnostic applications of radiation technology focus mainly on imaging. With advancements in the field of digital image processing more accurate images can be obtained by applying radiation technology.
X ray – earliest medical imaging technology
Discovery of X rays is one of the most important milestones in the progress of imaging technology. Introduced in 1895, X ray machines probably formed the first novel medical imaging device mainly applied for diagnostic purposes.
X rays are named so because their existence and properties were unknown at that time. They have high frequency and energy, with the ability to penetrate objects according to their physical properties and density.
Heated tungsten filament inside the X ray tube emits electrons which strike against a rotating anode disc. This causes the emission of X rays which are focussed in one direction with the help of a collimator. Emitted X rays pass through the human body and fall on a photographic plate. Parts of the exposed body where X rays penetrated appear darker(black) whereas other parts appear lighter(white).
For example, bones and other solid particles appear more clearly visible than other regions. X rays are primarily used to detect bone fractures. Any foreign particle lodged inside the human body can also be detected with the help of X rays.
CT scan – medical imaging processed with computers
Over the next few decades after the invention of X ray machine, theories forming the basis for CT scan were formulated. In the 1970’s, CT scan, also known as Computed Tomography was introduced as an advancement in radiation technology following the X ray scan.
CT scan also employs the usage of X rays but the images are relatively more clear. Details of soft tissues with varying thickness can also be read with CT scan. X ray generators revolve around the subject with X ray detectors moving on the other side. This produces slices of data concerning the scanned body part.
Portions of scanned organs with varying thickness and properties absorb X rays in varying scale. The resultant image is regenerated using computers. This stage of image processing is known as tomography. With the advent of CT scan, medical diagnosis took another step forward with clear images of the scanned body parts.
MRI scan – non-ionising and non-invasive medical imaging technique
MRI (Magnetic Resonance Imaging) technology is considerably one of the modern imaging techniques which replaces ionising radiation with magnetic field. Developed in the 1980s, MRI technology can be used to view soft tissues clearly. Most important application is the scanning of the brain which is a delicate organ.
The patient is placed on a bed which enters a narrow tube like structure. Strong magnetic field is applied inside which causes the protons in cell structure to get aligned. As the human body is mostly composed of water molecules, hydrogen atoms with one proton plays a vital role in imaging.
The aligned protons are forced to misalign by the application of radio waves for a short duration. Later the protons realign themselves and release some radio signals in the process. Such signals are received by MRI scanner and converted into images.
As every cell and tissue differ according to thickness and other properties, the time taken by their protons to release radio signals may differ. The receiver can use this data to translate the obtained data into images. Though MRI does not involve real radiation passing through the body to capture images, it is still considered as one of the amazing inventions in the field of radiation technology.
Therapeutic applications of Radiation technology
Apart from the photographic uses of radiation, they can also be used to treat certain illnesses and medical disorders. As longer exposure to radiation has the ability to affect and alter cell functions, they can be successfully employed to treat tumours.
Application of Radiation Technology in cancer treatment
One of the main applications of radiation technology is the treatment of cancer. As radiation has harmful effects on the body’s cells and tissues, this property can be effectively employed to kill cancer cells. Usage of radiation to kill tumours and cancer cells is under continuous research and many types of radiation exposure for cancer treatment has been formulated.
The type of radiation exposure depends upon the type of cancer and affected area. When high intensity radiation is exposed over the affected area, it has the potential to kill cancerous cells over the course of time. Repeated exposure may be required to completely kill cancer cells or prevent their growth.
In order to protect healthy cells from getting affected by radiation, more specific types of radiation treatment need to be formulated. Radiation emitting substances can be ingested in the form of capsules, which emit radiation over the affected area. Such radioactive materials can also be made to travel through the bloodstream thereby emitting radiation at the target organs.
Treatment of thyroid disorders with radioactive iodine
Thyroid gland secretes growth regulating hormones which are essential for a healthy balanced growth. Dysfunction of thyroid may cause hyperthyroidism and hypothyroidism. In the case of hyperthyroidism, whole or a part of the thyroid gland may need to be removed.
Radioactive Iodine can be taken orally which is absorbed by the thyroid gland. This could damage thyroid cells and acts as an effective treatment for hyperthyroidism. As a replacement for thyroid gland, medications are prescribed to balance deficient hormone levels. Radioactive Iodine, in this case, acts as the best option to treat thyroid disorders and thyroid cancer.