Chapter 25; Diagnostic Imaging Exam Associated Terms:

Chapter 25; Diagnostic Imaging Exam Associated Terms: Chapter 25; Diagnostic Imaging Exam Associated Terms: Cassette light-proof holder in which x-ray film is exposed Contrast Medium substance ingested or injected into the body to facilitate imaging of internal structures Film raw material on which x-rays are projected through the body; prior to processing, it does not contain a visible image (similar to photographic film) Fluoroscopy special x-ray technique for examining a body part by immediate projection onto a fluorescent screen Magnetic Resonance Imaging (MRI) imaging technique that uses a strong magnetic field Nuclear Medicine a branch of medicine that uses radioactive isotopes to diagnose and treat disease Radiograph processed film that contains a visible image Radiography art and science of producing diagnostic images with x-rays Radiologist physician who specializes in radiology; performs some procedures and interprets images to provide diagnostic information Radiology branch of medicine including diagnostic and therapeutic applications of x-rays Radiolucent permitting the passage of x-rays Radionuclide radioactive material with a short life that is used in small amounts in nuclear medicine studies Radiopaque not permeable to passage of x-rays Teleradiology use of computed imaging and information systems to transmit diagnostic images to distant locations Tomography procedure in which the x-ray tube and film move in relation to each other during exposure, blurring out all structures except those in the focal plane Ultrasound imaging technique that uses sound waves to diagnose or monitor various body structures X-Rays invisible electromagnetic radiation waves used in diagnosis and treatment of various disorders Diagnostic Imaging - Principles of Radiology Routine x-ray imaging, computed tomography (CT), sonography, magnetic resonance imaging (MRI), and nuclear medicine are now commonly used diagnostic and therapeutic procedures. Advances in radiation therapy continue to be at the forefront of the treatment for cancer. Radiology continues to evolve through technologic changes that provide ever-increasing diagnostic information to physicians. As the technology advances, the need to teach patients becomes even more important. Medical assistants are often directly involved in preparing patients for outpatient radiographic procedures, performing basic radiographic procedures in the medical office, and assisting in the general education process. X-Rays and X-Ray Medicines X-rays are high-energy waves that cannot be seen, heard, felt, tasted, or smelled and that can penetrate fairly dense objects, such as the human body. Diagnostically, these penetrating waves create two-dimensional shadow-like images on film that is similar to photographic film. Unprocessed film must be protected from light and kept in a special holder called a cassette before use. Once the film inside the cassette has been exposed to x-rays, the cassette is placed in a special machine that removes the film and processes it. The process film contains a visible image that is called a radiograph. The process by which the films are produced is called radiography. Electricity of extremely high voltage in the x-ray to produces x-rays. The x-rays leave the tube in one primary direction as a beam, through a device used to control the size of the beam. The light that shines on the patient is not part of the beam but is a positioning aid that illuminates the area covered by the beam. A patient may hear noises coming from the tube area during an exposure, but these are made by the equipment, not the x-rays. Images are formed on the x-ray film as the rays either pass through or are absorbed by the tissues of the body. Radiolucent tissues, such as air in the lungs, permit the passage of x-rays, while radiopaque tissues, such as bone, do not permit the passage of x-rays. Physicians who specialize in interpreting these images on the processed film are radiologist. Outpatient X-Rays In some states, you may be permitted to take and process simple images such as bone or chest radiographs. The training for medical assistants varies, but most curricula include a formal course in the theory of radiology and a written examination offered by the state radiographic association for the general operator. In other states, only licensed radiographers may take and process radiographs. You should be familiar with your state laws and comply with any regulations. How would you describe x-rays to a patient? X-rays are invisible, high-energy waves that travel at the speed of light. These waves penetrate the body, making an impression on a piece of film placed behind or in front of the area of the body being examined. While taking an x-ray is not painful, the x-rays may be harmful to certain internal organs. A lead-lined blanket may be placed over those areas of the body to protect internal organs. Patient Positioning The x-ray exposure on film is a two-dimensional image. Because the human body is a three-dimensional structure, x-ray examinations usually require a minimum of two exposures taking at 90° to each other. Other examinations necessitate three or more exposures at different angles. These different angles of exposure are the basis for standard positioning for x-ray examination. • Anteroposterior Position (AP) From front to back. When a chest x-ray is taken with the back against the film plate and the x-ray machine in front of the patient it is called an anteroposterior (AP) view. • Posteroanterior Position (PA) From back to front. When a chest x-ray is taken with the front against the film plate and the x-ray machine in back of the patient it is called an posteroanterior (PA) view. • Right Lateral Projection (RL) • Left Lateral Projection (LL)