Introduction
Computed tomography (CT) and Radionuclide imaging (RNI) are both a form of diagnostic imaging. Since they have been first introduced in medical imaging they both suffered a huge development over the years in terms of image acquisition and also patient radiation protection. The following essay it is going to focus on just a few important things that make CT and RNI similar and different in the same time. However this subject can be discussed in much depth, the focus is going to be on the similarities and differences of the physics imaging methods and also a small awareness of biological effects and radiation protection.
As a starting point in CT diagnostic imaging the form of radiation used to provide an image are x-rays photons , this can also be called an external radiation dose which detect a pathological condition of an organ or tissue and therefore it is more organ specific. However the physics process can be described as the radiation passes through the body it is received by a detector and then integrated by a computer to obtain a cross-sectional image (axial). In this case the ability of a CT scanner is to create only axial two dimensional images using a mathematical algorithm for image reconstruction. In contrast in RNI the main property for producing a diagnostic image involves the administration of small amounts of radiotracers or usually called radiopharmaceutical drugs to the patient by injection or oral. Radio meaning the emitted of gamma rays and pharmaceutical represents the compound to which a nuclide is bounded or attached. Unlike CT has the ability to give information about the physiological function of a body system. The radiopharmaceutical often referred to as a nuclide has the ability to emit ga...
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...s in one direction to acquire a single image slice. For another slice to be imaged the x-ray tube would again rotate another 360 degrees but on opposite direction. However this has been changed over the years and has been implemented a Slip-Ring technology which replaced the old high tension cables. In this way the new CT scanner x-ray tube had the ability to rotate continuously around the patient and in the same time the table was moving through the gantry to acquire data in a form of a Spiral or Helical. Therefore the new generation of CT scanners is called Spiral or Helical CT. The advantages of the new scanners are that the volume data can be reconstructed in any other planes (sagittal, coronal and three dimensional images), also there is a short time scan therefore radiation to the patient is minimized and also the artefact caused by patient motion is reduced.
the effective doses from diagnostic CT procedures are typically estimated to be in the range of 1 to 10 mSv. This range is not much less than the lowest doses of 5 to 20 mSv estimated to have been received by some of the Japanese survivors of the atomic bombs. These survivors, who are estimated to have experienced doses slightly larger than those encountered in CT, have demonstrated a small but increased radiation-related excess relative risk for
Spectral CT imaging has a lot of potential in the future; it is only a matter of developing the current ideas into better methods than they are now. The Dual-layer detector method is showing promise in its investigative trials. Olszewski says, “With the IQon Spectral CT, there is potential to identify the iodinated contrast within the image and allow for its selective visualization, thus allowing the elimination of the first step” (Lentz 2014), the first step being the non-contrast exam before hand. He goes on to say, “you have the ability to remove the contrast agent after the scan…”(Lentz 2014). If the claims Olszewski is making are true, it could cause large reductions in radiation doses to patients, shorter exam times for patient, and increased work efficiency for departments.
The role of the radiologist is one that has undergone numerous changes over the years and continues to evolve a rapid pace. Radiologists specialize in the diagnoses of disease through obtaining and interpreting medical images. There are a number of different devices and procedures at the disposal of a radiologist to aid him or her in these diagnoses’. Some images are obtained by using x-ray or other radioactive substances, others through the use of sound waves and the body’s natural magnetism. Another sector of radiology focuses on the treatment of certain diseases using radiation (RSNA). Due to vast clinical work and correlated studies, the radiologist may additionally sub-specialize in various areas. Some of these sub-specialties include breast imaging, cardiovascular, Computed Tomography (CT), diagnostic radiology, emergency, gastrointestinal, genitourinary, Magnetic Resonance Imaging (MRI), musculoskeletal, neuroradiology, nuclear medicine, pediatric radiology, radiobiology, and Ultrasound (Schenter). After spending a vast amount of time on research and going to internship at the hospital, I have come to realize that my passion in science has greatly intensified. Furthermore, both experiences helped to shape up my future goals more prominently than before, which is coupled with the fact that I have now established a profound interest in radiology, or rather nuclear medicine.
The description of PET scans in detail requires the understanding of the radioactive substance injected into the subject. First, a small amount of a biochemical substance is tagged with a positron-emitting radioisotope. A positron is an “anti-electron.” Positrons are given off during the decay of the nuclei of the radioisotope. When the positron emitted collides with an electron in the tissue of the subject, both the positron and the electron are annihilated. When this happens, the collision produces two gamma rays having the same energy (511 KeV), but going in opposite directions.
Johnston, J. (2012). Essentials of Radiographic Physics and Imaging. St Loius, Missouri: Elsevier Mosby Publishing.
Marshall, G. W and S. Keene. “Radiation Safety in the Modern Radiology Department: A Growing Concern.” The Internet Journal of Radiology 5.2 2007: N. pag. 24 Apr. 2011 .
Radiology technology is a science of using radiation to produce images. There are many jobs you can perform in diagnostic imaging usually a radiologic technologist will oft...
Radiation is something that the naked eye cannot see, yet has the potential to save lives one treatment at a time or even one image at a time. Since the discovery of x-rays in 1895, it has branched out into numerous modalities each independently specializing in their own ways. X rays are used to aid in the diagnosis and treatments of patients on a case by case scenario. Sometimes doctors can make a diagnosis on the same day or conclude that a patient will require radiation therapy within weeks to follow. Whatever it may be, the importance of x rays and radiation itself is a crucial part of the medical field when it comes to saving lives. Initially it all started with the discovery of x rays but then three years later radiation therapy was introduced to aid with
Radiation therapists work closely with patients to fight cancer. According to Health Care Careers, Oncologists, Dosimetrists and nurses are some of the professionals that a radiation therapist works with while caring for a cancer patient. This group of professionals will determine a specialized treatment plan. The first step usually includes a CT scan performed by a radiologist to find the exact area that needs to be targeted with x-rays. Next, the therapist uses a special machine that emits radiation called a Linear Accelerator. They use this machine during a treatment called external beam therapy. During this process, the Linear Accelerator will project x-rays at targeted cancer cells or tumors. Another therapist will be in a different room monitoring the patient’s viral signs until the procedure is over. The external therapy l...
Radiation is something that we are exposed to on a daily basis; it is in the air we breathe. Radiation is used in hospitals, research labs, and in many medical procedures. It is also commonly used as a treatment for cancer. In some cases it helps and in others it does not. Radiation is used for cancer treatment because it kills cells. The issue is that it is killing healthy cells at the same time it is killing cancerous cells. Even though medical imaging emits radiation, it makes it possible for us to detect injuries and significant diseases. Radiation is measured in a few different ways, and has numerous side effects on our body depending on the dosage. We are exposed to it in the environment unintentionally, and at times in treatment purposely. Additionally, there is current research in effort to reduce the amount of radiation in medical procedures.
CTscans stands for “Computed Tomography”. It is a way of looking inside your body using a special camera. It is an advanced scanning x-ray and computer system that makes detailed pictures of horizontal cross-sections of the body, or the part of the body that is x-rayed. A CT scan is a diagnostic test that combines the use of x-ray with computer technology. A series of x-beams from many different angles are used to get these cross-sectional images of the patient’s body. In a computer, these pictures are assembled into a 3-dimentianal picture that can display organs, tissues, bones, and any such thing. It can even show ducts, blood vessels and tumors. One of the advantages of CT is that it clearly shows soft tissue structures (such as brain), as well as dense tissue structure (such as bone). The pictures of a Ctscanner are a lot more detailed than the pictures of a regular X-ray machine. It can make pictures of areas protected or surrounded by bones, which a regular X-ray machine can not. Because of this, a CT scanner is said to be 100 times as affective and clever as an ordinary X-ray, and can therefore diagnose some diseases a lot earlier and quicker. It is recent technology that has made it possible to accurately scan objects into a computer in three dimensions, even though the machines and ideas were developed in the 1970s. In the 70s doctors started to use this new type of machine that could give detailed pictures of organs that the older type of x-ray, machine could not give.
An important change came about with the development and common use of computer technology. “Such use of a filmless radiology department was very interesting to this medical field. Digital radiography was introduced in the mid 1980’s and now competes with screen film radiography in all radiographic applications” (Bansal, 2006).
CT scans and MRIs, or are incorporated into them in a different way for a clearer picture of what is
This image portrays the first radiological advancement produced and expanded to the medical field. I say this because the radiological discovery created what is today known as imaging tests and/or diagnostic tests. X-rays are known to create a clear bone/skeletal transparency of the human body. Through time X-rays as well as other radiological techniques progress into a more useful resource for professionals. Although the discovery of the different types of ionizing radiation was historical and life changing in the life of science, the high levels of energy within that radiation process was also harmful. Many people/Medical Doctors were unaware that by having X-rays tested on them, they were exposing themselves to radiations sickness and even worse, cancer. After radiology was known to be dangerous, physicians and nuclear energy workers researched and found better ways to prevent the human body from being affected by the radiation. Since then, radiology has guided practitioners when trying to determine the location from where the disease began and how much the disease has spread since its initial state. “Use of highly conformal radiotherapy techniques has heightened the need for image-based verification of treatment delivery on a more frequent basis than just the weekly portal images” (Clinic Radiation Oncology chapter 6. Radiation Oncology Physics Pg.137). Radiation oncology has served as a form of
Images of human anatomy have been around for more than 500 years now. From the sketches created by Leonardo da Vinci, to the modern day Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan, images have played a great role in medicine. Evolution in medical imaging brought together people from various disciplines such as Biology, Physics, Chemistry and Mathematics, a collaboration which has further contributed to healthcare as a whole. Modern day imaging improves medical workflows by facilitating a non-invasive insight into human body, accurate and timely diagnostics, and persistence of an analysis.