View Chapter 2 Exposure 2.ppt from CHEM INORGANIC at Haines City Senior High School. 1 PRINCIPLES OF RADIOGRAPHIC IMAGING RADIATION CONCEPTS (CHAPTER TWO) RADIOGRAPHY IS BOTH AN ART AND A ... has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons. As you move down …
Depending on the exposure, measurement units for radiation exposure are millisieverts or rem (U.S. units). Single radiation exposure or a series of exposures over time may be employed to estimate the dose. A single exposure of 100 millisieverts (10 rem) or less would prevent cancer in 99 percent. A cancer diagnosis affects more than 40% of men ...
The second phase initiates the x-ray production process. The actual exposure is measured in milliseconds. 4. There are 2 designs for the anode. One is stationary this is basically a tungsten button embedded in a copper rod, it called stationary because it does not move. The second is a rotating anode used in general purpose tube today. 5.
The highest frequency that the human ear can detect is approximately 20 thousand cycles per second (20,000 Hz). This is where the sonic range ends, and where the ultrasonic range begins. – Ultrasound is used in electronic, navigational, industrial, and security applications. – It is also used in medicine to view internal organs of the body.
There are four major types of radiation: alpha, beta, neutrons, and electromagnetic waves such as gamma rays. They differ in mass, energy and how deeply they penetrate people and objects. The first is an alpha particle. These particles consist of two protons and two neutrons and are the heaviest type of radiation particle.
The U.S. Nuclear Regulatory Commission is an independent federal government agency responsible for regulating the commercial use of nuclear materials. This document is free of copyright and can be reproduced for educational purposes. Page Last Reviewed/Updated Thursday, March 19, 2020.
The figure (right) shows the differences. Neutrons, because they don't have any charge, don't interact with materials very well and will go a very long way. The only way to stop them is with large quantities of water or other materials made of very light atoms.
This is why they are useful in medicine—to show whether bones are broken or where there is tooth decay, or to locate a tumor.
Carbon-14, used in carbon-dating of fossils and other artifacts, also emits beta particles. Carbon-dating simply makes use of the fact that carbon-14 is radioactive. If you measure the beta particles, it tells you how much carbon-14 is left in the fossil, which allows you to calculate how long ago the organism was alive. The third is a neutron.
This can significantly alter the radiographic density. If the tube is too far away from the film, an insufficient number of x-ray photons strike the film , producing a light film (decreased radiographic density). And, if the tube is too close to the film, a greater number of x-ray photons, than are required, strike the film, producing a very dark film (increased radiographic density). This is known as the inverse square law and is expressed by the following formula:
X-rays are extremely inefficient in producing optical density (blackening) of the radiographic film. Because x-radiation is absorbed by tissue (and accumulated), any method to reduce dosage and yet provide a usable image is desirable. The intensifying screen is primarily responsible for making radiographic imaging a relatively safe medical diagnostic tool.
The goal of producing a radiographic image is to provide the greatest amount of usable information to aid in diagnosis. In medical radiography, there is no tolerance for anything other than the closest to reality that one can achieve. Consistency and faithful recording of anatomical structures with optimum detail are primary goals. Anything less is unacceptable for the interests of both the doctor and the patient.
THE IMAGE RECEPTOR. For over 100 years, radiography has used some form of film/intensifying screen combination as an image receptor. X-rays, after passing through the patient, interact with the image receptor, and a latent image (an invisible change that represents the object that was radiographed) forms in the film.
Other film characteristics to consider include contrast, speed, and light absorption. After selecting a film type, it must be matched to an appropriate intensifying screen. The choices for film contrast are high, medium, and low. High-contrast film produces more blacks and whites on the radiograph.
Cassettes are lighttight film and screen holders. They swing open on a hinge mechanism. The screens are permanently affixed inside the cassette, one on each side (if two screens are used). The film is “sandwiched” between the two screens; it must be loaded in the darkroom (unless one is using a daylight loading system). Most cassettes are rigid devices ( Figure 2-2 ); major film manufacturers may provide cassettes at little or no cost if you agree to use their film.
Radiographic quality refers to the exactness of representation of the anatomic structure on the radiograph within the useful density range. Quality is not easy to objectify and is influenced by radiographic noise and resolution.
A radioactive isotope will remain 15.625 grams after 30 years if its half-life is 6 years, and initial values are 500 grams. Similarly, the elapsed time t and the initial quantity N (0) of a radioactive isotope can also be calculated by following the same process.
The Half-Life calculator can be used to understand the radioactive decay principles. It can be used to calculate the half-life of a radioactive element, the time elapsed, initial quantity, and remaining quantity of an element. Half-life is a concept widely used in chemistry, physics, biology, and pharmacology.
The half-life of carbon-10, for example, is only 19 seconds, so it is impossible to find this isotope in nature. Uranium-233 has a half-life of about 160000 years, on the other hand. This shows the variation in the half-life of different elements.
patient is seen on January 23, 2010 by a primary care physician who is a member of University Associates. A cardiologist (also a member of University Associates) sees the patient on November 24, 2011. Would the visit on November 24th be classified as a new or established patient?
67-year-old patient with multiple medical problems is currently taking six prescriptions and several over-the-counter agents. The primary care physician has a concern about side effects; therefore, the patient is referred to a pharmacist for assessment and management of medications. The pharmacist assesses the treatment and makes recommendations during the 10-minute face-to-face visit.
The patient is a 59-year-old Gravida 3, Para 3, who was experiencing postmenopausal bleeding for the last five months and her evaluation included a normal endometrial biopsy. The patient also was found to have a right adnexal mass on CAT scan confirmed with ultrasound, as well as a small cystic mass in the left ovary. Given the patient’s age and despite a normal CA-125, the need for surgical evaluation of the complex adnexal mass was discussed. The patient also preferred a total abdominal hysterectomy to be performed because of postmenopausal bleeding and to see a definitive diagnosis and treatment of that condition. Informed consent was obtained for hysterectomy and bilateral salpingo-oophorectomy.
32-year-old female is referred to the Behavioral Health Clinic due to significant personality changes. A series of tests is administered to evaluate the patient’s emotionality, intellectual abilities, personality and psychopathology. The computerized test is completed in order to assist with establishing a diagnosis.
55-year-old patient (post LASIK surgery) visits a new ophthalmologist for extreme dry eyes. The physician performs an expanded problem-focused history and exam and prescribes eye drops as needed. What is the correct E/M code assignment for this service?