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© 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in.

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Presentation on theme: "© 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in."— Presentation transcript:

1 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Creating the Image Unit III

2 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Radiographic Film Chapter 19

3 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Objectives Describe components of radiographic film Explain production of silver halide crystals State purpose of various additives to radiographic film Describe latent image formation

4 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Objectives Discuss differences between direct exposure film, screen film, and films for various special applications, such as duplication Explain the fundamentals of proper film storage and handling

5 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Objectives Identify common radiographic film artifacts Discuss automated and daylight loading film systems Explain responsibilities involved in proper radiograph identification

6 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Photosensitive Film First image receptor chosen by Röntgen No longer most common image receptor because of predominance of digital imaging in 21 st century Knowledge of film/screen technology still required of radiographers

7 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Radiographic Film Construction Base Adhesive layer Emulsion Supercoat (overcoat)

8 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Radiographic Film Base Foundation of radiographic film –Flexible, yet durable –Uniformly radiolucent –Film must retain its size and shape throughout use and processing –Thickness ranges from micrometers –Modern base is thin sheet of polyester

9 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Base History Original base: –Glass Plates coated with emulsion –Difficult maintenance Exposure factors with plates very high Origin of term flat plate of abdomen

10 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cellulose Nitrate Replaced glass plates during World War I glass shortage Highly flammable Led to several devastating hospital fires in 1920s and 1930s

11 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cellulose Triacetate Safety base introduced in 1920s –Less flammable than Cellulose Nitrate Disadvantages: –Films would warp with age –Not as resilient as todays polyester films

12 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Polyester Base of todays modern film Introduced in 1960s

13 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Specializations of Film Base Blue tint –Reduces eyestrain –Increases diagnostic accuracy Crossover –Light from one screen exposed opposite emulsion Halation

14 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cassette Loading Single emulsion film –Emulsion side toward intensifying screen Emulsion side dull Non-emulsion side shiny –LL – notch in film in lower-left corner

15 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Adhesive Layer Binds emulsion to film base –Allows for proper emulsion distribution over base throughout use and processing

16 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Emulsion Heart of film Composed of silver halide crystals suspended in gelatin –Active ingredient photosensitive Silver halide crystals Typically 5-10 micrometers in thickness

17 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Gelatin Allows even distribution –Separate suspension of silver halide crystals Radiolucent Non-reactive Processing chemistry able to penetrate Low Z#

18 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Types of Silver Halide Crystals Silver bromide Silver iodide Silver chloride

19 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Duplitized Film Double emulsion or double coated film

20 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Supercoat/Overcoat Protective layer of gelatin –Provides sturdiness to unexposed radiographic film –Antistatic –Reduces damage from scratches, pressure, or contamination during storage, handling, and processing

21 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Manufacturing Radiographic Film All must take place in total darkness: –Crystal production –Ripening –Mixing –Coating

22 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Silver Halide Crystal Formation First step: –Pure metallic silver dissolved into nitric acid Forms silver nitrate Second step: –Silver nitrate combined with potassium bromide

23 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Silver Halide Crystal Formation Combination yields silver bromide and potassium nitrate Potassium nitrate is water soluble –Dissolves in water and washes away during production of emulsion

24 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Silver Halide Crystal Structure Resultant shape can be many varying forms –However, inner structure takes on cubic form or cubic lattice

25 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Sensitivity Speck Silver-gold-sulfide creates imperfections in crystals –Gives crystals good imaging properties –Result: Sensitivity center or sensitivity speck within crystal lattice

26 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Sensitivity Speck Allows for collection of many silver atoms in one area after being exposed to x-ray or light photons

27 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ripening Length of time crystals need to grow –Size and emulsion influence film factors After ripening complete: –Emulsion cooled –Shredded and washed Removes potassium nitrate

28 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Mixing Shredded emulsion heated and melted –Specific temperature –Sensitizes crystals

29 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Mixing Several extra ingredients may be added –Dyes Adjust spectral sensitivity –Fungicide/bactericide –Antifogging agents

30 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Spectral Sensitivity Panchromatic –Sensitive to all wavelengths Orthochromatic –Not sensitive to red Controlled by dyes added during mixing

31 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Coating Requires precise and expensive equipment Generates 40 rolls of film Layers on adhesive, then emulsion, then supercoat Film cut to size

32 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Latent Image Formation Gurney-Mott Theory (1938) X-ray and light photons deposit energy into silver halide crystals

33 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Latent Image Formation Energy disrupts bonds between atoms of crystal –Electron freed –Halide migrates into gelatin –Silver ion remains

34 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Latent Image Formation Sensitivity speck traps electron Silver ion attracted to sensitivity speck to neutralize it Process repeats itself

35 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Types of Film Direct exposure (nonscreen) Intensifying screen Duplication

36 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Film Storage and Handling Prior to exposure: –Storage On end –Age Expiration dates –Rotate stock –Heat Below 68ºF (20ºC)

37 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Film Storage and Handling Prior to exposure: –Humidity 30-60% –Light –Radiation

38 © 2013 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Film Identification Each exposure must include medical record information –Date of exposure –Full name of patient –Name of institution –Name of ordering physician –Patient identification number –Type of exam


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