Introduction to RADIOGRAPHY/What is medical imagine technique?
Radiography is called the “Eye of Medicine” because without this medical imaging field, no one would be able to diagnose or cure diseases within the body which could not be able to see by the naked eye. The history of the eye of medicine started on 8th November 1895, with the discovery of invisible rays by Wilhelm Conrad Roentgen. Due to the unknown nature of these invisible rays, he named them X-rays. He found that these invisible rays can pass through certain substances and produce shadows on photographic plates. Therefore he chose the glass photographic plate as the image recording medium for the radiographic imaging of the internal body structures. Starting from 1896 February up to today this invisible rays and photographic plate outbreak the field of medicine.
What is Medical Radiography?
Radiography in the medical field uses both ionizing and non-ionizing radiation for diagnosis as well as for treatments. Ionizing radiation can ionize the particles as they pass through the body, therefore they cause more burden to human beings. However, they can be used to produce images of internal body structures. Imaging with non-ionizing radiation does not cause such harm to the body and therefore they are safer than imaging with ionizing radiation. MRI and Ultrasound are the best examples of modalities which use non-ionizing radiation in the medical imaging field. Even though the modality uses ionizing or non-ionizing radiation, it is necessary to assess the risks and benefits of the radiographer before planning an examination for the diagnosis or treatment of a disease.
Medical imaging with ionizing or non-ionizing radiation is done with various equipment. Some of them are Computed Tomography (CT), Positron Emission Tomography (PET), Single Photon Emission Tomography (SPECT), Magnetic Resonance Imaging (MRI), Fluoroscopy, Dental X-ray, Plain Radiography, Dual Energy X-ray Absorptiometry (DEXA), Mammography, Ultrasonography, C- arms used in theatres etc. Some of these produce dynamic images and some of these produce static images. Some of them are using ionizing radiation and some use nonionizing radiation. According to the region of interest or the type of tissue being to be imaged the model of imaging and the equipment that can be used may vary. One of the most relevant examples is breast imaging with mammography equipment. The breast is composed of soft tissues and therefore it is necessary to be cautious when selecting the type of radiation. It should not be too high or too low energy because too high energy X rays can pass through the breast without any interaction and hit on the detector and too low energy X rays may absorb by the breast tissues without reaching the detector. Therefore the equipment should use an optimum energy range with suitable filters and detectors to obtain an optimum quality diagnostic image. In this way, each and every piece of equipment used for imaging purpose have many specifications according to its use.
Whatever the equipment or type of radiation used, the common feature for all of this equipment are the radiation source and the detector or the field of detectors which are capable of capturing the radiation beam transmitted through the internal organs or the body. Starting from X-ray, the source of energy is changed to sound waves, gamma rays, and high energy particles such as alpha, and beta rays. The detector was changed from a photographic plate to gas-filled detectors, scintillation detectors, and solid-state detectors due to the continuous advancement of technology day by day.
Radiography in the medical field is not only used for diagnosis purposes, but also for delivering treatments. This is another sub-branch of the medical imaging field which is known as Radiotherapy. It mainly focuses on cancer treatments by using high-energy radiation. This field also has various kinds of equipment and namely some of them are a linear accelerator, Cobalt-60 units, low dose; high dose; conventional brachytherapy units and low to orthovoltage X-ray units.
Radiography cannot be confined to only the field of medicine. It has another branch called industrial radiography. In this field, ionizing radiations mainly X-rays and gamma rays are used to detect cracks and flaws in materials. The most important advantage of using radiography in the industrial field is the ability to inspect the materials without any damage or movement of the material itself before launching the product to the market for selling. Mainly this checking is done for gas and oil pipelines, boilers, metal welding, and vehicle and aircraft parts. The basis for this checking depends on the detection of transmitted X-rays or gamma rays that passed through the object which is captured by the radiation detector. Based on the amount of attenuated beam on the detector, it can be determined whether the materials have any inner flows or cracks with thinner material which course more radiation to be passed through the object and hit on the detector.
Radiation Protection in Radiography
Although the radiation worker in the field of medicine or in the field of industry, it is necessary to consider about radiation protection. Every radiation worker has an annual radiation limit of 20 mSv/yr (mili Sievert per year). Radiation workers must wear radiation monitoring badges and radiation protective equipment where necessary. There are many types of radiation monitoring devices and some are showing the instant reading in digital format while some are showing the stored cumulative dose. For radiation protection, the mainly used material is lead. There are many types of lead protective devices are created for radiation workers to protect from harmful ionizing radiation. Lead thyroid collars, gonad shields, lead aprons, lead goggles, head caps, lead gloves and boots are some examples of radiation protection devices. Not only that, but also it is necessary to consider the location or the construction of a building which uses ionizing radiation inside it. All the walls and doors of that building should be constructed according to international standards which reduce the attenuated radiation to the radiation workers as well as to the general public.
Radiography in Future…
With the development of technology, the radiography field is entering new pathways day by day. The first revolution was the capturing of images by a computer in digital format. Then step by step it has come to the stage of three-dimensional (3D) imaging. Now the use of artificial intelligence (AI) is the latest passion in this field. Each and every modality in this noble field minimizes human intervention by using this AI technology. Automatic detection of the pathology or disease with high precession and curing the disease accurately by minimizing human errors are trending objectives of artificial intelligence nowadays. Medical imaging will be the overturned domain of the medical field because without RADIOGRAPHY your doctor will be blind…