Fluoroscopic Imaging and Radiography Concepts

The removal of air from the glass envelope surrounding the x-ray tube to prevent interference with x-ray production.

A coiled wire made of tungsten, a metal that can withstand extremely high temperatures. It is heated by an electrical current.

The process of releasing electrons from the filament when it is heated to a high temperature.

The cloud of electrons that builds up around the filament after thermionic emission. The electrons repel each other creating a negative charge.

Electrons are propelled from the negatively charged cathode (filament) towards the positively charged anode (target) due to electromagnetic attraction.

The reduction in the intensity of an x-ray beam as it passes through matter.

A digital image processing technique that automatically adjusts the brightness levels of an image to optimize visualization.

The amount of light emitted by a source, measured in units of candela.

A type of digital radiography that employs a photostimulable phosphor plate to capture x-ray photons.

The difference in density between adjacent areas within an x-ray image.

The misrepresentation of an object's true size or shape in an image.

An increase in the apparent size of an object in an image.

The distance between the object being imaged and the image receptor.

The distance between the x-ray source and the image receptor.

A type of distortion where objects appear shorter than they actually are.

The amount of exposure an image receptor receives during an x-ray exam. It directly affects the darkness or lightness of the image.

The range of exposures that can be used to produce an acceptable image. A large exposure latitude means the system can tolerate a wider range of exposures, making it more forgiving of technical errors.

A process where x-rays are produced and captured to create an image of the inside of a patient's body.

The device that produces X-rays, consisting of a cathode (filament) and an anode (target).

A system that captures x-ray information directly using a digital sensor, producing an image without film or cassettes.

A measure of the difference in density between adjacent areas on an X-ray image, determining how well we can distinguish between different tissues.

The conversion of high-speed electrons into x-ray photons when they collide with the target.

The specific point within the x-ray tube where electrons hit and generate x-rays.

A bundle of x-ray photons that exit the x-ray tube.

The difference in density between adjacent areas on an x-ray image. Think of it as the visibility and separation between different structures.

The amount of attenuating material needed to reduce the x-ray beam's intensity by half. This reflects the beam's penetrating power.

The sharpness with which objects are represented on an image. This makes the details of the image clearer or more defined.

Patient movement during an x-ray can blur the image, making it difficult to see structures clearly.

A smaller focal spot size in the x-ray tube creates sharper images, allowing for a more detailed view. Larger focal spots give quicker exposures.

The inverse square law states that the intensity of radiation decreases proportionally to the square of the distance from the source. It means that as the distance doubles, the intensity decreases by a factor of four.

The exposure maintenance formula ensures that the exposure level remains constant even when the distance between the x-ray source and the image receptor is changed. It states that the mAs value should be adjusted proportionally to the square of the distance change to maintain the same level of exposure.

kVp affects the penetrability of the x-ray beam and ultimately influences the contrast of the image. High kVp (greater energy) produces a 'long scale' of contrast, where many shades of gray are visible. Low kVp produces a 'short scale' of contrast, with fewer shades of gray and more distinct black and white areas.

Bit depth refers to the number of bits used to represent each pixel in a digital image. Higher bit depth allows for a greater range of gray levels (from black to white). For example, 8-bit depth allows for 256 shades of gray, while 10-bit depth allows for 1024 shades of gray.

Materials that absorb a large amount of radiation and prevent most x-rays from passing through. They appear bright white on an x-ray image.

Materials that allow most x-rays to pass through with ease. They appear dark on an x-ray image.

A device that reduces scatter radiation, which improves image quality, but increases the patient's radiation dose.

The amount of x-ray photons produced at the tube. It controls the overall darkness (density) of the image.

Controls the penetrating power of the x-ray beam. Determines the contrast between different tissues.

The distance between the x-ray source and the image receptor. Affects the intensity and divergence of the beam.