RADT_153_Unit_6_Exam - RADT 153 Image Analysis Unit 6 Unit...

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Unformatted text preview: RADT 153 Image Analysis Unit 6 Unit Exam The Effects of Distance on Radiographic Quality 2 6.0 The Effects of Distance on Radiographic Quality Unit Exam Directions: 1. Write your name and the date on your Scantron form. Identify the subject as the course number (for example, RADT 101) along with the test number (for example, Unit 1). 2. For each of the questions below, select the best answer to the question. 3. Using a No. 2 pencil, fill in the appropriate answer on the answer sheet. 4. Erase unwanted answers completely. Questions with two or more filled in answer spaces are graded as incorrect. 5. Answer all questions. 6. You have a maximum 15 minutes to complete the following 25 questions. (Note this time factor approximates the amount of time you would be allowed to answer the same number of questions on the Registry examination in radiography) ------------------------------------------------------------------------------------------------1 Three terms that may be used when referring to the distance from focal spot to image receptor are... A. B. C. D. E. 2. TFD, TLD, SID TFD, SID, FFD SID, FFD, LPO OID, RPO, OTC DID, OID, FFD Focal film distance (FFD) is the distance between the focal spot (on anode) and the ____________. A. B. C. D. E. object patient cathode film table 3 3. As FFD increases, the intensity decreases while the area covered increases proportionally to the square of the distances from the source. A. B. 4. OFD is also commonly referred to as ____________. A. B. C. D. E. 5. x-ray tube x-ray table radiographer patient high voltage transformer To minimize magnification and also provide for optimal structural definition, OFD is usually kept to a maximum. A. B. 7. FFD FID OID OAD SID OFD is the distance from the _________ to the film or image receptor. A. B. C. D. E. 6. True False True False The inverse square law refers to the change in light (or x-ray) intensity that takes place from a change in ____________. A. B. C. D. E. mAs kVp filtration temperature distance 4 8. There is an exposure level of 14 mR at a 30 inch distance. What would be the intensity at a 40-inch distance? A. B. C. D. E. 9. When radiation quantity is changed because the intensity is altered, adjustments should be made with ____________. A. B. C. D. E. 10. True False If a situation requires 50 mAs in a 40” FFD, how much mAs should be used when the FFD is limited to 35?" A. B. C. D. E. 12. kVp OID filtration mAs seconds The mAs-distance formula (law) is also referred to as the square law. A. B. 11. 5.321 mR 10.124 mR 150 mR 7.875 2 mR 24 36.2 38.3 60 100 If SID is being reduced, mAs will have to __________ to keep film density the same on the film. A. B. C. D. E. be reduced be increased be turned off stay the same (film density cannot be the same if FFD is changed) 5 13. As FFD is increased, film density decreases. A. B. 14. ___________ and ___________ are the two types of radiation that make up the density of a radiograph. A. B. C. D. E. 15. 10:1 7:1 11:1 50:1 2:1 A 10-inch air-gap technique is as good as a ________ grid. A. B. C. D. E. 18. Compton scatter the inverse square law the square law demagnification air-gap technique A 5-inch air-gap technique is nearly as efficient as a _____ grid. A. B. C. D. E. 17. Secondary, scatter Fog, mottle Penumbra, umbra Primary, scatter Gamma, x-ray Increasing the space between the film and the patient and increasing the SID to offset magnification results in. A. B. C. D. E. 16. True False 10:1 7:1 15:1 20:1 2:1 As OID increases -- the amount of scatter radiation reaching the film decreases. A. B. True False 6 19. The relationship between OFD and radiographic contrast is: A. B. C. D. E. 20. Two factors that effect recorded detail are ________ and ____________. A. B. C. D. E. 21. Target, Object, Image Alignment Filtration Positioning Motion Distance A shorter FFD reduces magnification. A. B. 25. True False A critical factor in determining size distortion. A. B. C. D. E. 24. True False A longer OFD results in improved definition of image details. A. B. 23. SID, OID mAs, kVp film emulsion, x-ray intensity patient motion, Tube, Object, Image Allignment air-gap technique, grids A longer FFD results in improved definition of image details. A. B. 22. inverse direct air-gap decreasing increasing True False Increased OID results in increased size distortion. A. B. True False ...
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