Introduction
The term x-ray is familiar as early as since I was at primary school. At that time, I thought of it as a transparent glass that when a person stands behind it, we can see his bones from it. Of course, this view is very much influenced by cartoons and TV shows.
When I got admitted into Matriculation Center IIUM, I need to bring along my chest x-ray film. At that time, I thought that the job as a radiographer is easy, because the radiographer only asked me to stand still in front of a white board. Later, when I completed my study in Matriculation Center, I was planning to apply for Radiography course. Aside from what I already have in mind, I actually have no idea what is a radiographer and what is his job and career.
First Exposure in Medical Imaging
In this semester, I was exposed to the real meaning of x-ray, radiography, and medical imaging – from 3 core subjects, namely Introduction to Diagnostic Imaging, Analog Image Processing, and Radiation Physics. I also was being introduced to the real working environment of a radiographer from the trips to Hospital Tengku Ampuan Afzan (HTAA) and Hospital Sultan Haji Ahmad Shah (HoSHAS).
In those hospitals, they have their own Department of Diagnostic Imaging. Diagnostic imaging is same with medical imaging, which is a specialized area of health services that deals with the production of human anatomy images, which assist in diagnosing diseases. This area of specialization was formerly known as radiographic imaging (due to the use of radiation), but since the advancement in imaging technology that includes the Magnetic Resonance Imaging (MRI) and ultrasound which doesn’t use radiation, it’s now better known as medical imaging.
Radiation and Attenuation
First thing first, we must know the principle of the medical imaging, which is the concept of radiation. The real meaning of radiation is actually the emission and transmission of energy when matter undergoes changes. It can be in the form of rays, waves or particles, and can be spontaneous or induced.
In regards of medical imaging, we make use of x-ray photon. When an x-ray photon interacts with matter, basically 2 things will happen; either no change or it will be attenuated. Attenuation is the key interaction in image production, and can be simplified in the following 4W1H question:
• What – reduction of energy / change in direction experienced by an x-ray atom
• Who – the patient
• Where – inside human body
• When – as it interacts with matter
• How – Compton and Photoelectric Process
Image Production
The image production relates closely with the concept of the patient as the beam emitter. As the x-ray enters human body, it will be attenuated and the exits towards the image receptor. Different patient / examination need different setting of kV, mAs, and source-image distance to produce a quality image. There’s no exact formula that can be used on all patients and all examinations.
Beam collimation also needs to be adjusted according to the region of interest so that the image produced includes all the anatomical part needed to be diagnosed. There are some cases in HTAA and HoSHAS where the image produced is rejected as it cuts the anatomical part that’s going to be diagnosed.
Types of Modalities
In HTAA and HoSHAS, we are exposed to various kind of imaging modalities. Those modalities can be divided into 2 major groups: either radiation based or non-radiation based
• Radiation Based Modalities
The one commonly used in these hospitals is the plain radiography. Plain radiography is divided into 3 types: the conventional radiography, the digital radiography and computerized radiography. Each of it has its own advantage and disadvantage.
Conventional radiography is mainly used in Accident and Emergency (A&E) department because it can resolve image faster. Despite that, we can’t adjust the image produced, and if there’s something wrong in the image, we have to repeat the test using new cassette.
By using computerized radiography, we can adjust the image before printing, thus saving the cassette if the image is unacceptable. There’s one case in HTAA where a patient undergo chest x-ray had to repeat the test 3 times due to improper centering of the beam, thus affecting the view of the region of interest. Imagine using the conventional radiography, there will be 2 films that are going to be wasted. Although we can adjust the image before printing, the cost of the film is approximately double the cost of conventional radiography, as the image is documented on laser films.
Digital Radiography is more advanced than computerized radiography as it doesn’t make use of imaging plate to capture the image and the image can be obtained in seconds, but the machine is expensive and the resolution of the image is less (10-12 line pairs per mm) compared to conventional film (14 line pairs per mm).
CT scan is a modality that takes multiple images of human body and later compiled them into a complete, cross sectional image of soft tissue, bone and blood vessel. It may use contrast media (CM) to facilitate the view of images. Example of CM that is commonly used is iopamidol. In HTAA, the CT scan machine can take up to 4 slices per rotation, while in HoSHAS, the machine can take up to 6 slices per rotation.
In fluoroscopy, we can obtain a real-time image of the internal organ of the patient. Usually, fluoroscopy is used to study the digestive tract by using CM (barium swallow for upper gastrointestinal tract and barium edema for lower gastrointestinal tract).
• Non-radiation based modalities
There are 2 types of modalities present in HTAA and HoSHAS: MRI and ultrasound. Of all modalities in medical imaging, MRI is the one that makes me thrilled. MRI makes use of magnetic field to obtain the image of the human anatomy. The level of detail that we can see is so extraordinary compared to other imaging modalities as we can manipulate what we want to view. For example, if we want to see fat tissue, we use T1-hyperintense. If we want to see fluids, we use T2-hyperintense.
In ultrasound, we use sound wave to view internal part of human body in real time. It is not harmful compared to fluoroscopy as it doesn’t make use of radiation (although the concept of attenuation is still applied in this modality). Despite that, the screen is small (from what I saw in HTAA) thus we must move the transducer a lot on the patient’s body. To optimize the wave transmission and facilitate the moving of transducer, we use clear gel made mainly of aqua.
Types of Examination and Patient Preparation
There are mainly 2 types of examination; plain radiological and specialized radiological examination. For plain radiological examination, generally patient must remove any radiopaque substances from the region of interest. Examples are chest x-ray and skull x-ray. For abdominal and pelvic examination, it might involve bowel preparation – the patient cannot eat high residue food, and is advised to fast before the exam. There’s additional rule governing women in child bearing age, that they must apply the 28 day rule (meaning that she has had a period within the last 28 days).
In specialized radiological examination, we usually make use of contrast media (CM). Therefore, before we administer the CM, consent form must be filled and the patient needs to be screened for possible allergies and sensitivity to CM. For example, patient who is allergic to seafood might suffer the allergy effect when iopamidol (used in CT scan) is administered. In this case, we need to use prednisolone to combat the effect of the allergies. They also need to be monitored for their vital signs like electrocardiogram (ECG) and blood pressure.
During the examination, there are rules needed to be adhered to for the image to be optimum. Generally, a patient – by hook or by crook – needs to limit movement including breathing. This is important as any movement will make the image blurred, causing test repeats. There’s a case in HTAA involving a baby, his mother must be present inside the room to calm him and limit his movement (the mother has to wear lead gown, of course). Other specific instruction is depending on the type of examination, for example, straining in Micturating Cystourethrogram (MCUG).
Conclusion
The advancement of technology nowadays enables us to provide a better healthcare thus make it possible to provide a better quality of life. Seeing how radiographers work – every image well captured and every mistake they made – gives me a clear overview of the course, makes me realize the benefit and hazard of the job towards me and patients, and has taught me how important this field of healthcare towards human benefit. I never regretted a second by my choice of this course, and I made a promise to myself to be a good radiographer – for the sake of humanity, and in the end to achieve Allah’s pleasure.
(1, 491 words)
Declaration
I, Muhammad Ridha Bin Abdul Rahman (0819771), hereby declare that this work is entirely my own.
……………………………….
The term x-ray is familiar as early as since I was at primary school. At that time, I thought of it as a transparent glass that when a person stands behind it, we can see his bones from it. Of course, this view is very much influenced by cartoons and TV shows.
When I got admitted into Matriculation Center IIUM, I need to bring along my chest x-ray film. At that time, I thought that the job as a radiographer is easy, because the radiographer only asked me to stand still in front of a white board. Later, when I completed my study in Matriculation Center, I was planning to apply for Radiography course. Aside from what I already have in mind, I actually have no idea what is a radiographer and what is his job and career.
First Exposure in Medical Imaging
In this semester, I was exposed to the real meaning of x-ray, radiography, and medical imaging – from 3 core subjects, namely Introduction to Diagnostic Imaging, Analog Image Processing, and Radiation Physics. I also was being introduced to the real working environment of a radiographer from the trips to Hospital Tengku Ampuan Afzan (HTAA) and Hospital Sultan Haji Ahmad Shah (HoSHAS).
In those hospitals, they have their own Department of Diagnostic Imaging. Diagnostic imaging is same with medical imaging, which is a specialized area of health services that deals with the production of human anatomy images, which assist in diagnosing diseases. This area of specialization was formerly known as radiographic imaging (due to the use of radiation), but since the advancement in imaging technology that includes the Magnetic Resonance Imaging (MRI) and ultrasound which doesn’t use radiation, it’s now better known as medical imaging.
Radiation and Attenuation
First thing first, we must know the principle of the medical imaging, which is the concept of radiation. The real meaning of radiation is actually the emission and transmission of energy when matter undergoes changes. It can be in the form of rays, waves or particles, and can be spontaneous or induced.
In regards of medical imaging, we make use of x-ray photon. When an x-ray photon interacts with matter, basically 2 things will happen; either no change or it will be attenuated. Attenuation is the key interaction in image production, and can be simplified in the following 4W1H question:
• What – reduction of energy / change in direction experienced by an x-ray atom
• Who – the patient
• Where – inside human body
• When – as it interacts with matter
• How – Compton and Photoelectric Process
Image Production
The image production relates closely with the concept of the patient as the beam emitter. As the x-ray enters human body, it will be attenuated and the exits towards the image receptor. Different patient / examination need different setting of kV, mAs, and source-image distance to produce a quality image. There’s no exact formula that can be used on all patients and all examinations.
Beam collimation also needs to be adjusted according to the region of interest so that the image produced includes all the anatomical part needed to be diagnosed. There are some cases in HTAA and HoSHAS where the image produced is rejected as it cuts the anatomical part that’s going to be diagnosed.
Types of Modalities
In HTAA and HoSHAS, we are exposed to various kind of imaging modalities. Those modalities can be divided into 2 major groups: either radiation based or non-radiation based
• Radiation Based Modalities
The one commonly used in these hospitals is the plain radiography. Plain radiography is divided into 3 types: the conventional radiography, the digital radiography and computerized radiography. Each of it has its own advantage and disadvantage.
Conventional radiography is mainly used in Accident and Emergency (A&E) department because it can resolve image faster. Despite that, we can’t adjust the image produced, and if there’s something wrong in the image, we have to repeat the test using new cassette.
By using computerized radiography, we can adjust the image before printing, thus saving the cassette if the image is unacceptable. There’s one case in HTAA where a patient undergo chest x-ray had to repeat the test 3 times due to improper centering of the beam, thus affecting the view of the region of interest. Imagine using the conventional radiography, there will be 2 films that are going to be wasted. Although we can adjust the image before printing, the cost of the film is approximately double the cost of conventional radiography, as the image is documented on laser films.
Digital Radiography is more advanced than computerized radiography as it doesn’t make use of imaging plate to capture the image and the image can be obtained in seconds, but the machine is expensive and the resolution of the image is less (10-12 line pairs per mm) compared to conventional film (14 line pairs per mm).
CT scan is a modality that takes multiple images of human body and later compiled them into a complete, cross sectional image of soft tissue, bone and blood vessel. It may use contrast media (CM) to facilitate the view of images. Example of CM that is commonly used is iopamidol. In HTAA, the CT scan machine can take up to 4 slices per rotation, while in HoSHAS, the machine can take up to 6 slices per rotation.
In fluoroscopy, we can obtain a real-time image of the internal organ of the patient. Usually, fluoroscopy is used to study the digestive tract by using CM (barium swallow for upper gastrointestinal tract and barium edema for lower gastrointestinal tract).
• Non-radiation based modalities
There are 2 types of modalities present in HTAA and HoSHAS: MRI and ultrasound. Of all modalities in medical imaging, MRI is the one that makes me thrilled. MRI makes use of magnetic field to obtain the image of the human anatomy. The level of detail that we can see is so extraordinary compared to other imaging modalities as we can manipulate what we want to view. For example, if we want to see fat tissue, we use T1-hyperintense. If we want to see fluids, we use T2-hyperintense.
In ultrasound, we use sound wave to view internal part of human body in real time. It is not harmful compared to fluoroscopy as it doesn’t make use of radiation (although the concept of attenuation is still applied in this modality). Despite that, the screen is small (from what I saw in HTAA) thus we must move the transducer a lot on the patient’s body. To optimize the wave transmission and facilitate the moving of transducer, we use clear gel made mainly of aqua.
Types of Examination and Patient Preparation
There are mainly 2 types of examination; plain radiological and specialized radiological examination. For plain radiological examination, generally patient must remove any radiopaque substances from the region of interest. Examples are chest x-ray and skull x-ray. For abdominal and pelvic examination, it might involve bowel preparation – the patient cannot eat high residue food, and is advised to fast before the exam. There’s additional rule governing women in child bearing age, that they must apply the 28 day rule (meaning that she has had a period within the last 28 days).
In specialized radiological examination, we usually make use of contrast media (CM). Therefore, before we administer the CM, consent form must be filled and the patient needs to be screened for possible allergies and sensitivity to CM. For example, patient who is allergic to seafood might suffer the allergy effect when iopamidol (used in CT scan) is administered. In this case, we need to use prednisolone to combat the effect of the allergies. They also need to be monitored for their vital signs like electrocardiogram (ECG) and blood pressure.
During the examination, there are rules needed to be adhered to for the image to be optimum. Generally, a patient – by hook or by crook – needs to limit movement including breathing. This is important as any movement will make the image blurred, causing test repeats. There’s a case in HTAA involving a baby, his mother must be present inside the room to calm him and limit his movement (the mother has to wear lead gown, of course). Other specific instruction is depending on the type of examination, for example, straining in Micturating Cystourethrogram (MCUG).
Conclusion
The advancement of technology nowadays enables us to provide a better healthcare thus make it possible to provide a better quality of life. Seeing how radiographers work – every image well captured and every mistake they made – gives me a clear overview of the course, makes me realize the benefit and hazard of the job towards me and patients, and has taught me how important this field of healthcare towards human benefit. I never regretted a second by my choice of this course, and I made a promise to myself to be a good radiographer – for the sake of humanity, and in the end to achieve Allah’s pleasure.
(1, 491 words)
Declaration
I, Muhammad Ridha Bin Abdul Rahman (0819771), hereby declare that this work is entirely my own.
……………………………….
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