Podcast
Questions and Answers
What is the primary purpose of the base in radiographic film?
What is the primary purpose of the base in radiographic film?
- To contribute to image distortion
- To act as a medium for color development
- To provide a rigid structure for interaction with x-rays or light photons (correct)
- To enhance the sensitivity of light reception
What is the thickness of the emulsion layer on radiographic film?
What is the thickness of the emulsion layer on radiographic film?
- 1 to 2 µm
- 3 to 5 µm (correct)
- 5 to 7 µm
- 10 to 15 µm
What is the main function of gelatin in photographic emulsion?
What is the main function of gelatin in photographic emulsion?
- To vary the color sensitivity of the film
- To increase the speed of x-ray penetration
- To act as a developer for silver halide crystals
- To provide mechanical support by holding silver halide crystals in place (correct)
What is the active ingredient of the radiographic emulsion?
What is the active ingredient of the radiographic emulsion?
What effect does crossover have in radiographic film?
What effect does crossover have in radiographic film?
Darkroom should be adjacent to the_______ room
Darkroom should be adjacent to the_______ room
4 Layers of Intensifying Screen
4 Layers of Intensifying Screen
What condition is essential for the performance of an automatic processor?
What condition is essential for the performance of an automatic processor?
Where should the darkroom be located?
Where should the darkroom be located?
What percentage should the humidity in the darkroom should be?
What percentage should the humidity in the darkroom should be?
What is the primary characteristic of fluorescence in phosphors?
What is the primary characteristic of fluorescence in phosphors?
Which statement is true about the thickness of phosphor layers?
Which statement is true about the thickness of phosphor layers?
What is true regarding the crystal size in radiographic screens?
What is true regarding the crystal size in radiographic screens?
What does Detective Quantum Efficiency (DQE) measure?
What does Detective Quantum Efficiency (DQE) measure?
What does Conversion Efficiency (CE) refer to?
What does Conversion Efficiency (CE) refer to?
Which component is NOT a principal part of radiographic film?
Which component is NOT a principal part of radiographic film?
safe light handling time
safe light handling time
4 Types of entrances sa darkroom ( Kapoy english megs )
4 Types of entrances sa darkroom ( Kapoy english megs )
What is the role of the protective coating in an intensifying screen?
What is the role of the protective coating in an intensifying screen?
What is the primary substance used as a phosphor in the intensifying screen?
What is the primary substance used as a phosphor in the intensifying screen?
Which of the following is NOT a rare earth element used in modern screens?
Which of the following is NOT a rare earth element used in modern screens?
What function does the reflective layer serve in an intensifying screen?
What function does the reflective layer serve in an intensifying screen?
Which layer is farthest from the film in an intensifying screen?
Which layer is farthest from the film in an intensifying screen?
What is luminescence?
What is luminescence?
Which statement about the phosphor in an intensifying screen is correct?
Which statement about the phosphor in an intensifying screen is correct?
What is the primary material used to construct the base of an intensifying screen?
What is the primary material used to construct the base of an intensifying screen?
What is the main role of a darkroom in the film processing environment?
What is the main role of a darkroom in the film processing environment?
What are the components of the silver halide emulsion mentioned?
What are the components of the silver halide emulsion mentioned?
Which image type is referred to as the visible image after processing?
Which image type is referred to as the visible image after processing?
What is the atomic number of bromine (Br)?
What is the atomic number of bromine (Br)?
What is the primary problem caused by the crossover effect?
What is the primary problem caused by the crossover effect?
which is true about direct safelighting?
which is true about direct safelighting?
What does a latent image refer to in the image formation process?
What does a latent image refer to in the image formation process?
Which feature is essential for a darkroom to effectively process films?
Which feature is essential for a darkroom to effectively process films?
Study Notes
Protective Coating
- Transparent to light, protects phosphors from abrasion and handling damage.
- Ensures a surface is available for cleaning while preserving phosphor integrity.
Phosphor
- Acts as the active layer in intensifying screens, emitting light when exposed to X-rays.
- Commonly used phosphor: Calcium Tungstate.
- Modern screens utilize rare earth elements like Gadolinium, Lanthanum, and Yttrium for improved performance.
Reflective Layer
- Essential for redirecting isotropically emitted light from phosphors to the film.
- Without it, only half of the emitted light would interact with the film, decreasing image quality.
Base
- The layer farthest from the film, typically made of polyester.
- Provides stability and maintains size during use and processing.
Luminescence
- Luminescent materials emit light in response to stimuli.
- Two types:
- Fluorescence: Emits visible light during stimulation.
- Phosphorescence: Continues emissions post-exposure.
Properties of Screens
- Phosphor composition: Rare earth screens enhance X-ray to light conversion.
- Phosphor thickness influences light production; thicker layers yield higher light output, suitable for high-speed screens.
- Crystal Size: Larger crystals produce more light; detail screens utilize smaller crystals.
- Crystal concentration correlates with speed; higher concentrations result in faster screens.
Rare-Earth Screen Materials
- Detective Quantum Efficiency (DQE): Measures the ability to absorb photons; higher atomic number indicates better performance (57-71).
- Conversion Efficiency (CE): Quantifies light emitted per X-ray exposure.
Radiographic Film
- Comprises two main components:
- Base: Provides structural support without distorting images, maintaining size during processing.
- Emulsion: Contains gelatin and silver halide crystals; crucial for interacting with X-rays and light photons.
Gelatin and Silver Halide Crystals
- Gelatin supports and evenly distributes silver halide crystals.
- Silver halide crystals (98% silver bromide and 2% silver iodide) are the active element for radiation exposure, with bromine, silver, and iodine having atomic numbers 35, 47, and 53, respectively.
Crossover Effect
- Results from emulsion exposure caused by light from opposite intensifying screens.
- Leads to image blurring, known as crossover effect, compromising image clarity.
Image Formation
- X-rays convert to light photons, creating a latent image, which is invisible until processed.
- Chemical processing reveals the manifest image, making it visible.
Processing Room Requirements
- Centrally located dark room designed for safe film handling and processing without light exposure.
- Accessible amenities like power and water supply are essential.
- Efficient automatic processors should be in place, and the X-ray apparatus must be appropriately positioned to avoid damage to the darkroom.
- Air ventilation and heating are crucial for maintaining satisfactory working conditions in the processing room.
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Description
This quiz explores key concepts related to radiological imaging, including protective coatings, phosphors, reflective layers, and luminescence. Understand the vital roles of these components in enhancing image quality and stability. Dive into the science of how light is emitted and redirected in the context of modern imaging systems.
