1. Kenneth L. Bontrager John P. Lampignano Image Quality, Digital Technology, and Radiation Protection Copyright © 2010 by Mosby, Inc., an affiliate of Elsevier Inc.

2. Image Quality Factors — Film-Screen Systems 1. Density 2. Contrast 3. Resolution 4. Distortion

9. Compensating Filters Wedge filter Boomerang filter

10. Benefits of Compensating Filter

13. Off-Center Grid Cutoff

14. Off-Level Grid Cutoff

15. Off-Focus Grid Cutoff

16. Upside-Down Grid Cutoff

18. Motion Voluntary motion (breathing) Involuntary motion (peristalsis)

19. Image Quality Summary Chart 1. Small focal spot — Use small focal spot whenever possible to improve detail. 2. Shorter exposure time — Use shortest exposure time possible to control voluntary and involuntary motion. 3. Film-screen speed — Use faster film-screen speed to control voluntary and involuntary motion. 4. SID — Use longer SID to improve detail. 5. OID — Use shorter OID to improve detail.

20. Focal Spot Size

25. Digits parallel — joint open Digits not parallel — joints not open

34. Image Quality in Digital Radiography

36. Processing digital image Exposure controls — kV, mAs, and time

38. Brightness AP shoulder — high brightness AP shoulder — less brightness Intensity of light representing individual pixels in image

39. Contrast Differences in brightness between light and dark areas of image AP shoulder — higher contrast AP shoulder — lower contrast

43. Exposure Index Dependent on the intensity of the radiation striking the detector, which is the effect of – mAs – kV – Total detector area irradiated – Objects exposed (air, metal implants, patient anatomy)

44. Low exposure index (high “S” number) — Underexposed Acceptable exposure index

45. High exposure index (low “S” number) Acceptable exposure index

47. Acceptable SNR (good image quality) Low SNR (poor image quality)

50. Chest without any post-processing Chest with image reversal

51. Nonsubtracted AP shoulder Subtracted and magnified shoulder angiogram

57. Computed Radiography (CR)

58. Image Plate Reader/Processor and Workstation

59. Why is it important to collimate and use lead blockers with CR?

60. Direct Digital Radiography (DR)

61. DR Chest Imaging System

62. DR Mammography Unit

63. Steps of Image Production Comparison Film-screen Computed radiography (CR) Direct digital radiography (DR)

64. PACS Network

74. Fluoroscopy exposure patterns (without tower drape shields in place)

75. Worker Protection During Fluoroscopy Fluoroscopy exposure patterns (with tower drape shields in place)

77. Thyroid shield with protective apron

83. Vinyl-covered lead shield

90. Image Quality, Digital Technology, and Radiation Protection - The End - Chapter 2