VIII. Image Evaluation Flashcards
Evidence of Appropriate Exposure Level
Exposure indicator
Ensures the patient receives the correct amount of radiation for optimal image quality.
Overexposure leads to loss of contrast, while underexposure causes noise.
Evidence of Appropriate Exposure Level
Exposure indicator
Noise due to underexposure:
Noise is due to insufficient exposure and appears as graininess.
*Recorded Detail *
Image blur
Caused by motion or improper focus.
*Recorded Detail *
Spatial resolution
High resolution ensures clear visualization of small structures.
*Recorded Detail *
Distortion
Avoided by proper alignment of the source, patient, and detector.
*Recorded Detail *
Mottle
Grainy appearance due to underexposure or noise in the image.
Artifacts
Unwanted elements that reduce image quality.
Artifacts
Motion
Blurring due to patient movement.
Artifacts
Metal “star” artifacts
Caused by metallic objects.
Artifacts
Beam hardening
Dark streaks caused by dense structures like bone.
Artifacts
Partial volume
Occur when structures of different densities are averaged together.
Artifacts
Causes
Equipment errors, patient movement, or improper technique.
Artifacts
Effects
Artifacts
Preventative measures
Use immobilization devices, ensure proper technique, and remove metal objects.
*Display Contrast *
Brightness
Controlled by window level adjustments.
*Display Contrast *
Ambient lighting
Bright surroundings reduce the visibility of image contrast.
*Display Contrast *
Window width and level
Window width adjusts contrast, and window level adjusts brightness.
