RADT_153_Unit_2_Exam

RADT_153_Unit_2_Exam - 2.0 Unit 2 Exam: The Geometric...

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Unformatted text preview: 2.0 Unit 2 Exam: The Geometric Properties of Image formation Directions: 1. Write your name and the date on your Scantron form. Identify the subject as the couse number (ex: RADT 153) along with the test number (ex: 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 your 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. This reduces the ability of the x-ray film to optimally record sharply defined detail. A. B. C. D. E. Gray-scale effect Density Penumbra effect Contrast Latitude 2. Which of the following is NOT an imaging characteristic that is observed on a radiograph as a source of unsharpness of image details. A. B. C. D. E. Geometric Screen Motion unsharpness Film size None of the above 2 3. Geometric unsharpness is the unsharpness in a radiographic image due to the relative distance between the focal spot the object being radiographed, and the film. A. B. True False 4. Which of the following is a way in which radiographers have learned to control for minimal penumbral effect of geometric unsharpness. A. B. C. D. E. Small focal spots Short focal-film distances Maximum object film distances Large focal spots None of the above 5. Which of the following contributes to screen unsharpness. A. B. C. D. E. Size of the screen Poor film-screen contact Excellent film-screen contact Grid ratio None of the above 6. Which of the following is NOT one of the speeds used to classify conventional intensifying screens. A. B. C. D. E. Slow-speed screens Par-speed screens High-speed screens Super-fast screens Non Screen Holder (CBH) 7. Rare-earth type screens have the advantage of being the fastest available. A. B. True False 8. The use of screen film in direct-exposure holders produces minimal image sharpness. A. B. True False 3 9. What contributes to sharply defined radiographic images? A. B. C. D. E. 10. The loss of recorded detail in a radiographic image as a result of movement of the x-ray tube, patient, or recording medium is called? A. B. C. D. E. 11. effect lag blurring unsharpness coefficient Using long-exposure times Using immobilization techniques Using short-exposure times Both A and B Both B and C What is the recommended exposure time to stop heart motion? A. B. C. D. E. 13. Motion Motion Motion Motion Motion How do radiographers control the effects of unsharpness due to motion? A. B. C. D. E. 12. No film-screen contact Minimal film-screen contact Close film-screen contact None of the above All of the above .01 .02 .03 .04 .05 Which type of intensifying screen allows for the shortest exposure times? A. B. C. D. E. High-speed intensifying screens Rare-earth type screens Medium-speed screens Fine / Detail Card Board Holder 4 14. A type of distortion. A. B. C. D. E. 15. Size distortion is the same as magnification. A. B. 16. True false Macroradiography is a technique used in which the structural details of the radiographic image are deliberately magnified using fractional focusing x-ray tubes at increased object film distances. A. B. 18. True False Imaging the actual size of the anatomical part requires the radiographer to increase OID. A. B. 17. Size distortion Motion distortion Shape distortion Both A and B Both A and C True False Which of the following is the equation used to calculate the magnification factor? A. Object width Image width B. Object height Image height C. Image height Object height D. Image width Object width F. Image length Object length 5 19. Which of the following is the equation used to calculate the percentage of magnification? A B. (Object width- Image width) x 100 Image width C. (Image width – Object width) x 100 Object width D. 20. (Image width – Object width) x 100 Image width (Object width – Image width) x 100 Object width Which of the following is NOT a way radiographers control size distortion of the structural details of a radiographic image. A. B. C. D. E. 21. The misrepresentation of the true image through foreshortening or elongation of the structural details of the radiographic image is called shape distortion. A. B. 22. Object Film Distance (OFD) Focus-to-Object Distance (FOD) Source-to- Image Distance (FFD) All of the above None of the above True False Calculate the percentage of magnification if Image Width is 32 inches, and Object Width is 20 inches. A. B. C. D. E. 40% 50% 60% 70% 80% 6 23. Calculate the magnification factor if Image Width is 40 inches, and Object Width is 20 inches. A. B. C. D. E. 24. 2 .5 5 .05 .2 Which of the following sets of information will result in the least amount of geometric unsharpness? A. B. 25. Focal Spot Size: 0.3 mm Object Film Distance: 2.0 in. Focus Object Distance: 38 in. Focal Spot Size: 0.6 mm Object Film Distance: 4.0 in. Focus Object Distance: 36 in. Which screen speed is designed for optimum definition of image details? A. B. C. D. E. Slow-speed screens Par-speed screens High-speed screens Super-fast screens Rare-earth screens 7 ...
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