Fluoroscopy Exam Questions Complete Solutions Current Update

Fluoroscopy Exam Questions Complete Solutions Current Update -What does Dynamic means: - Answers - -Always active or changing. -Having or showing a lot of energy. -Of or relating to energy, motion, or physical force. Fluoroscopy allows for? - Answers - -Imaging of the movement of internal structures. Can visualize function and motion in real time. -Commonly used for GI, vascular, and urinary studies, ect. -This often requires the use of contrast media. When and by whom was fluoroscopy invented? - Answers - -Thomas Edison. -1896 What is the typical X-ray tube current in fluoroscopy? - Answers - -5 mA -Can range from .5 to 5 mA -Compare this to a radiograph which can range from 50-1200 mA. A, Fluoroscopic system used for dynamic imaging of internal structures. B, Major components of an image intensifier. - Answers - They used to use (blank) screens - Answers - "Fluoroscopic" screens Used to require (blank) minutes of dark adaptation. - Answers - "15" minutes of dark adaptation (blank) used for night or dim vision have reduced visual acuity - Answers - Rods (blank) are used for day vision - Answers - Cones The (Blank) receives the x-ray beam during fluoroscopy - Answers - Image Intensifier (ii). X-rays that exit the patient are (blank) on the ii - Answers - Incident The ii converts the x-rays into (blank) - Answers - High intensity visible light image. The ii exists within a (blank) to protect and support it. - Answers - Tube-glass or metal-housed within a metal structure. X-rays are (blank) through the glass envelope - Answers - Transmitted They (x-rays) interact with the (blank) - Answers - Input phosphor (cesium iodide) The energy is converted to (blank) - Answers - Visible light The light intensity emitted by the input phosphor (cesium iodide) is equal to the intensity of the (blank) - Answers - Exit radiation This light then interacts with the (blank) - Answers - Photocathode The photocathode is composed of (blank) - Answers - Cesium and Antimony These compounds emit (blank) - Answers - Electrons The process is called (blank) - Answers - Photoemission Many (blank) photons are needed to emit (blank) electron. - Answers - -Light photons -One electron Electrons are (blank) from photocathode to an anode. - Answers - Accelerated The potential difference is of (blank) - Answers - 25kV The electrons pass through a (blank) in the middle of the anode. - Answers - Hole AKA focal point They then interact with an (blank) - Answers - Output Phosphor The output phosphor is composed of (blank) - Answers - Zinc cadmium sulfide What does ESD stand for? - Answers - Entrance skin dose Standard ii - Answers - Electrons move from (blank) to anode - Answers - Photocathode Electrons pass through a hole in the anode to reach the (blank) - Answers - Output phosphor (composed of zinc cadmium sulfide) Electrons interact with output phosphor producing (blank) - Answers - light Large pattern of electrons must be reduced. (Blank) reduces electron stream. - Answers - Electrostatic lenses Each photo-electron produces (blank) times more light than was necessary to create it. - Answers - 50-75 times more Path of energy in the ii - Answers - Flux gain - Answers - Minification gain - Answers - -Is the reduction in size of the output phosphor image compared to the input phosphor image. -Is the square of the diameter of the input phosphor compared to the output phosphor. -Output phosphor sizes usually between 2.5cm or 5cm. -Input phosphor sizes vary from 10cm to 40cm. How do we calculate Brightness gain? - Answers - Brightness gain = minification gain X flux gain Conversion factor - Answers - -Is Luminance of the output phosphor divided by input exposure rate. -Amounts to approximately 1% of brightness gain. How do we measure luminance? - Answers - Candela per square meter How do we measure exposure to an object? - Answers - Milli-Gray per sec Image intensifiers have CF's of 50 to 300 - Answers - Which corresponds to brightness gains of 5,000 to 30,000.