Radiographic Imaging Course
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Questions and Answers

Photography is a record made by means of ______ light

visible

Radiography is a record made by ______ radiation.

X-ray

The formation of a visible image is a ______ way step process.

two

The image chain includes a ______ image that is invisible on the radiographic film until processing occurs.

<p>latent</p> Signup and view all the answers

Primary radiation is the ______ beam after it exits the X-ray tube and before it interacts with the patient's body.

<p>X-ray</p> Signup and view all the answers

Remnant radiation is the ______ of radiation after it passes through the patient's body.

<p>remainder</p> Signup and view all the answers

Materials that allow X-ray photons to pass through easily are called ______.

<p>radiolucent</p> Signup and view all the answers

Bone has a ______ absorption of X-rays (white).

<p>high</p> Signup and view all the answers

The penetrating power of radiation depends on the ______ number.

<p>atomic</p> Signup and view all the answers

Silver halide is a chemical compound formed between silver and one of the ______.

<p>halogens</p> Signup and view all the answers

Silver halides are used in ______ film and photographic paper.

<p>photographic</p> Signup and view all the answers

Silver halides, except for ______ fluoride, are extremely insoluble in water.

<p>silver</p> Signup and view all the answers

A ______ compound is formed between silver and one of the halogens.

<p>chemical</p> Signup and view all the answers

[Blank] materials use silver bromide.

<p>Negative</p> Signup and view all the answers

Silver iodide is never used ______.

<p>alone</p> Signup and view all the answers

Certain positive materials use ______ chloride.

<p>silver</p> Signup and view all the answers

The photosensitive layer containing silver halide is suspended in ______ (on an x-ray film).

<p>gelatin</p> Signup and view all the answers

Change occurs in the silver halide ______ on exposure to light

<p>grains</p> Signup and view all the answers

A photographic emulsion is a dispersion of small solid particles in a ______ medium.

<p>liquid</p> Signup and view all the answers

Photographic emulsion is made by adding a solution of ______ nitrate into a warm gelatine solution

<p>silver</p> Signup and view all the answers

Silver ______ (AgBr) is produced by mixing aqueous solutions of silver ions and halide ions

<p>bromide</p> Signup and view all the answers

Light sensitive materials are affected by ______ and temperature

<p>moisture</p> Signup and view all the answers

The characteristics of sensitive emulsion include ______ and contrast

<p>speed</p> Signup and view all the answers

The speed of the emulsion depends on the ______ of silver halide crystal

<p>size</p> Signup and view all the answers

A ______ image is an invisible image formed on a film as a result of exposure to radiation

<p>latent</p> Signup and view all the answers

Photographic emulsion consists of light and X-ray sensitive ______ and gelatin.

<p>crystal</p> Signup and view all the answers

Silver bromide (AgBr) is a ______ crystal containing millions of pairs of ions

<p>lattice</p> Signup and view all the answers

Gelatin is a ______, colorless, brittle, nearly tasteless, extracted from the collagen inside animals' skin and bones.

<p>translucent</p> Signup and view all the answers

Gelatin acts as the medium for the formation of ______ halide crystals during chemical production.

<p>silver</p> Signup and view all the answers

The contrast of the emulsion depends on the ______ of size of the grains

<p>distribution</p> Signup and view all the answers

Gelatin maintains the uniform distribution of ______ halide in the liquid emulsion.

<p>silver</p> Signup and view all the answers

The exposure latitude of the emulsion is affected by the ______ of grain sizes

<p>range</p> Signup and view all the answers

In solid state, gelatin can be ______ and then allows penetration by the chemical agents.

<p>wetted</p> Signup and view all the answers

Gelatin holds firmly in position the ______ silver particles.

<p>metallic</p> Signup and view all the answers

Gelatin provides a ______ medium, enabling viewing of the image.

<p>transparent</p> Signup and view all the answers

Gelatin is a ______ medium for the formation of silver halide crystals during chemical production.

<p>suitable</p> Signup and view all the answers

Each silver bromide grain contains on the order of ______ atoms.

<p>109</p> Signup and view all the answers

Silver bromide grains are irregularly shaped like ______ or grains of sand.

<p>sugar</p> Signup and view all the answers

When solid silver bromide is formed, the silver atoms each give up one ______ electron to a bromine atom.

<p>orbital</p> Signup and view all the answers

The silver atoms, lacking one negative charge, have an effective ______ charge and are known as silver ions.

<p>positive</p> Signup and view all the answers

The bromine atoms, on the other hand, have gained an ______ and have become bromine ions.

<p>electron</p> Signup and view all the answers

When a photon of light of energy greater than a certain minimum value is absorbed in a silver bromide crystal, it releases an ______ from a bromide ion.

<p>electron</p> Signup and view all the answers

The negatively charged trap can then attract an ______ silver ion because the silver ion is charged positively.

<p>interstitial</p> Signup and view all the answers

The whole cycle can recur several, or many, times at a single trap, each cycle involving absorption of one ______ and addition of one silver atom to the aggregate.

<p>photon</p> Signup and view all the answers

Study Notes

Radiographic Imaging

  • Radiography is a record made by means of X-ray radiation, whereas photography is a record made by means of visible light
  • Formation of a visible image is a two-way step process:
    • Exposure of the film to light produces an invisible latent image
    • Chemical process that converts the latent image into a visible image with a range of density, or shades of gray

Image Production by X-Radiation

  • The image chain:
    • Latent image: an invisible image on the radiographic film until processing occurs
    • Radiograph: an image produced by X-ray photons on a piece of radiographic film
  • Terms related to image production:
    • Primary radiation: X-ray beam after it exits the X-ray tube and before it interacts with the patient's body
    • Remnant radiation: remainder of radiation after it passes through the patient's body, producing the image on the radiographic film
    • Secondary scatter radiation: radiation that may not reach the film but does not carry any useful information
    • Attenuation: process by which primary radiation is changed or absorbed as it travels through the patient
    • Radiolucent: materials that allow X-ray photons to pass through easily (e.g., air)
    • Radiopaque: materials that do not allow X-ray photons to pass through easily (e.g., bone)

Tissue Absorption of X-Rays

  • Different tissues in the body absorb X-rays at different extents:
    • Bone: high absorption (white)
    • Tissue: middle absorption (gray)
    • Air: low absorption (black)

X-Ray Beam Interaction with Body

  • As X-ray beam passes through the body:
    • Absorbed
    • Transmitted
    • Scattered
  • Factors affecting X-ray beam interaction:
    • Penetrating power of radiation
    • Atomic number
    • Density
    • Thickness of the material

Silver Halides

  • A silver halide is a chemical compound formed between silver and one of the halogens (e.g., silver bromide, silver iodide, silver chloride, silver fluoride)
  • Applications: light sensitivity, used in photographic film and radiographic film and paper
  • Properties of silver halides:
    • Except for silver fluoride, extremely insoluble in water
    • Undergo change when exposed to visible light or X-ray radiation

Photographic Emulsions

  • A photographic emulsion consists of:
    • Light and X-ray sensitive crystals (silver halides) suspended in gelatin
    • Coated on a transparent base of the film
  • Properties of gelatin:
    • Acts as the medium for formation of silver halide crystals during chemical production
    • Maintains uniform distribution of silver halide
    • Does not react chemically with silver halides
    • Allows the film base to be coated evenly with warm liquid emulsion, which is then chilled and allowed to set and dry
    • Holds firmly in position the metallic silver particles
    • Provides a transparent medium, enabling viewing of the image

Making an X-Ray Film Emulsion

  • Chemical process by which the X-ray film material is produced: precipitation
  • Photographic emulsion is made by adding a solution of silver nitrate into a warm gelatine solution containing potassium bromide, sodium chloride, or other alkali metal halides at suitable proportions
  • Silver nitrate (AgNO3) + potassium bromide --> silver bromide (AgBr) + potassium nitrate (KNO3)

Light-Sensitive Materials

  • Affected by:
    • Moisture and temperature
    • Presence of impurities
    • Exposure to certain gases
    • Airborne dust
    • Static electricity and mechanical stress
  • Characteristics of sensitive emulsion:
    • Speed: need for more or less exposure to light and X-ray radiation in comparison to inherent property of film emulsion to respond to light and X-ray radiation
    • Contrast: the way in which the material reacts to a range of exposures by showing on development a number of different densities

Latent Image Formation

  • Structure of crystals:
    • Silver bromide is a lattice crystal containing millions of pairs of ions
    • Silver bromide grains are irregularly shaped like sugar or grains of sand
  • When solid silver bromide is formed, as in the preparation of a photographic emulsion, the silver atoms each give up one orbital electron to a bromine atom
  • The liberated electron is free to wander about the crystal, and as it does, it may encounter a latent image site and be "trapped" there, giving the latent-image site a negative electrical charge

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Description

This quiz covers the basics of radiographic imaging, including principles of photography, film materials, sensitometry, film storage, intensifying screens, X-ray film cassettes, film processing, digital radiography, and image quality.

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