Attenuation is the reduction in the total number of photons remaining in the beam after passing the thickness of the object. This is results of interaction of photons with the object and being absorbed or scattered. As the x-ray beam pass through the patient , the beam will attenuated , and also it depend on part thickness , If the thickness is increased the density of the image will reduced ( ↑ thickness ↑ attenuation ↓ density ). The attenuation is affected by the type of absorber which high atomic number material will have high attenuation (↑ atomic number ↑ attenuation), this is due to the electrons of material interact with the photons (bone high interact with the photons because it composed of calcium). The composition …show more content…
• Chronic osteomyelitis – bone infection. • Hydrocephalus – dilation of the fluid filled the cerebral ventricle. • Osteoblastic metastases – spread of the cancer. • Osteochondroma – tumor. • Paget's disease – increase the bone cell activity. • Sclerosis – increase in hardening. The pathology that decreased the attenuation (destructive): These diseases absorbed less radiations and requires from the radiographer to decrease the exposure factors to compensate for the changes in the body tissues. The mAs should decrease 50%. The decrease of mAs 25-50% will compensate most of destructive diseases. Conditions affecting multiple sites: • Anorexia nervosa – psychological eating disorder. • Atrophy – wasting away of the body tissue. • Emaciation – generalized wasting away of body tissue. Conditions of the chest: • Emphysema – over distention of the lung tissue by air. • Pneumothorax – free air in pleural cavity. Conditions of the abdomen: • Aerophagia – psychological disorder. • Bowel obstruction – obstruction in the bowel. Conditions of the extremities and skull: • Active osteomyelitis – loss of bone tissue. • Aseptic necrosis – death of bone tissue. • Carcinoma – malignancies in
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
This chapter provides some insight into pulse wave analysis and its relation to arterial diseases. The shape of the arterial pulse wave is an augmentation of the forward traveling wave with the reflected wave. The amount of wave reflection is dependent on the arterial wall properties such as arterial stiffness and is expressed in terms of Augmentation Index. This approach has been studied extensively using various measuring techniques, all of which have respective advantages and disadvantages. The purpose of PWA can be seen in the section describing the medical conditions that affect the wave shape. The discussion is included to assist the reader in understanding the purpose of pulse wave analysis.
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.
Since the beginning of the propitious world, the core aspect that keeps it thriving is the propensity for people to discover innovations; however, progress of the past is, systematically, detrimental to the future. Not long after the revolutionary invention of the X-ray in the late 19th Century, an unprecedented number of medical examiners noticed (unknown to the time) radiation burns all over their body; decades later, an extraordinary surge in cancer cases had arisen. Perhaps, during the course of these years, scientists and researchers desired to further progress the x-ray (into the immense subsidiaries that are here today), and disregarded any flaws in the apparatus. This systematic inclination continues into the present time as Gary Marshall and Shane Keene notes in their 2007 article, “New technologies allow for patients to be overexposed routinely, and also allow for repeats to be taken quickly, making it easier for a technologist to multiply the patients dose without considering the implications” (5). The gaffes of radiology are present not only in the diagnostic setting, but also in the surgical and therapeutic areas. Working with radiation, it is imperative that the staff is aware of mistakes that are potentially fatal not only for patients, but themselves. It is especially important for medical radiologists to be cognizant of pediatric patients. The standard practice of pediatric radiology in the United States is to follow the step-by step formula from which adult patients are treated and diagnosed. There are copious consequences for following this technique since a child naturally has less body mass and a weaker immune and lymphatic system to manage radiation and its adverse effects. Medical radiology, being a...
Driver, (2013), described the DEXA scanner as a machine that produces two x-ray beams of high and low energy levels. Much like fluoroscopy, the x-ray from the DEXA scanner comes from underneath the patient, and the scanner has a very low x-ray dose. Earlier versions of the DEXA scanner emitted radiation which required up to five minutes to scan an area of interest, but the more advanced machines can take as ...
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...
...b done but can bring more side effects to the patient. Radiation is a connection to physics, which was a very important important discovery in science because it has cured many patients who have been affected by cancer when before they were left to die. Radiation therapy, like any other way exposed to radiation, can be a risk. The importance of undergoing this treatment is to see the positive side of it, not just think of the bad things that can come out of the radiation therapy. There is a risk of second cancers but isn’t it worth it? This treatment gives patients the chance to live a longer and normal life, this wasn’t an option before, so it’s important to be thankful for being born in this time period. Radiation might not be seen as a good thing in many occasions but it is now used for the good of the people affected by cancer, it’s a second chance for life.
The various decision making models on the decision to drop the bomb are, a rational actor model, organizational model, and a model of bureaucratic politics. President Truman used the rational actor model to make his decision to drop the bombs on Hiroshima and Nagasaki. “Rational actor theory treats the actions of governments and large organization as the acts of individuals”(Davidson and Lytle, 2010). Government leaders usually select the best option that will achieve the best result and at the lowest cost. Governments need to examine a set of goals, the evaluate the, then picks the goal with the highest payoff. “The appeal of this model lies in its predictive powers. Often enough, governments do not make clear why they act. On other occasions, they announce their goals but keep their strategies for achieving them secret”(Davidson and Lytle, 2010). Using standards of rational behavior help analysts put together leaps for the government’s unclear goals or actions. The model explains the progression of events that brought about the bomb’s development. First, several physicists saw that there was a possibility of nuclear fusion, Second, Roosevelt ordered speedup for the recovery period, Then, there were scientific breakthroughs that led to a higher certainty of success and lastly, the race with Germany and Japanese resistance in far east encouraged several scientists to push for success. “Although this outline of key decisions proceeds logically enough, there are troubling features to it, suggesting limits to the rational actor model”(Davidson and Lytle, 2010). Roosevelt is a rational actor model but there have been several committees and subgroups that were involved in the process. “Historians have offered contradictory answers ...
How does the X-ray work? Well first off let me tell you the difference of light rays and X-rays. The light rays are visible light waves and x-rays is a light that is smaller than atoms in your body. You can’t see them with the naked eye like sun rays. X-rays will only pick up items and body parts that are hard and also made of calcium. That light will then project your muscle that would look like a light gray and your bone structure that will be white onto a black piece of radio graphic film.
Apart of becoming a new patient at a dental office is taking an x-ray and some may have question along with taking an x-ray, like “will I be affected by the x-ray?” or “will I get cancer?”, “how long will it take” “are x-ray’s safe?”, the list goes on and on. So in this paper we will talk about different types of radiation affects such as affects on children and pregnant women as well as some things that may help reduce some of the radiation that may harm the human body.
indicates towards a fraud. On eof the most important qualities or benefits of this model is that it understands the pattern in the data and generates the result. Once the result is generated the model checks as to how close was the result from the actual results. Based on this analysis the model adjusts its weights to give an accurate result the next time. Once this model has been trained to give accurate results, it can be used to analyze other data as well. Even when Neural Networks are widely accepted, they are not really used that much in the marketing industry merely by the fact that data preparation for this model is very complex time consuming as compared to the Regression Analysis. The marketers are much comfortable using the Regression Analysis over Neural Networks because of the ease of interpreting the results in the Regression Analysis.
Although no adverse health effects have been directly linked to low-dose radiation exposure, the medical community is playing it safe with regards to radiation. Most physicians are very careful about ordering radiologic tests. They should not order a study unless it will improve patient care. If you have a question about the importance or the necessity of a radiologic test that has been ordered for you, be sure to ask your physician.
The Repressive hypothesis states how we currently live in a sexual repressed society. The repressive hypothesis also states that sexuality needs to be liberated, or that it does not have to be repressed. Identifying with ones sexuality is the key to unlocking ones identity and one’s happiness. The repressive hypothesis initially implies three edicts; that derive from our repressed society. According to the repressive hypothesis, specifically in the repressive culture we live in, the first edict explains how all sexuality must be silenced in all occasions, for the mention of sexuality is taboo. In modern times, specifically within the 17th century, it was also important to keep sexuality “hush-hush”, only those who belong to the lower class
The halo effect phenomenon is researched by Nisbett & Wilson (1977) and published in their experimental paper titled The Halo Effect: Evidence for Unconscious Alteration of Judgments and will be the main topic of this paper. The halo effect, also known as the physical attractiveness stereotype is a form of cognitive bias in which we assume that people who are physically attractive are also blessed with other appealing attributes such as kindness and intelligence. Limited information about the halo effect is known, and experiments conducted on the topic are even scarcer. This stereotype is portrayed to us at a young age through most Disney movies where we learn that if something is beautiful it is also good. A prime example is Cinderella and
As x-rays exit the patient, they interact with a cesium iodide input phosphor which converts the x-ray energy into visible light. Cesium iodide crystals are a tightly packed layer of linear needles which help improve spatial resolution by allowing little light dispersion. Attached to the input phosphor is the photocathode. Bushong describes the photocathode as, “a thin metal layer usually composed of cesium and antinomy compounds that respond to stimulation of input phosphor light by the emission of electrons.”