Radiology 1 - adiographic errors and artifacts by Dr Walid S. Salem

Описание: Radiographic Errors and Artifacts: Causes and Prevention
1. Importance of Avoiding Errors
: We aim to avoid radiographic errors for three main reasons:
• Patient Safety: To avoid re-taking the image, which exposes the patient to an unnecessary extra dose of radiation that has harmful biological effects.
• Resource Management: Re-takes waste time, films, and processing chemicals, leading to financial loss.
• Diagnostic Accuracy: Errors can cause interference in interpretation, leading to a wrong diagnosis and making the film useless.
2. Classification of Errors
: Errors are generally categorized into three types based on when they occur:
• Technique Errors: Occur during patient preparation and film placement.
• Exposure Errors: Occur during the X-ray exposure time.
• Processing Errors: Occur during the developing and fixing stages in the darkroom.
3. Technique Errors
• Patient Preparation: Failure to remove metal objects like earrings, removable dentures, piercings, or glasses results in radio-opaque artifacts that obscure anatomy (e.g., hiding caries or bone loss)
. In panoramas, jewelry can cause "ghost shadows" that appear larger and on the opposite side
• Movement: Patient or machine movement during exposure results in a blurred image
• Pressure Artifacts: Biting too hard on the film can cut the emulsion (white line/spot) or sensitize it (black line)
. Using fingernails or heavy pressure from pens while writing on the film can also leave black or white crescent marks
• Film Placement Issues:
◦ Reversed Film: Placing the film backward shows the lead foil pattern (dots, tire tracks, or herringbone) and results in a faint image
◦ Apices Cut-off: Placing the film too far out results in missing the root tips
◦ Dropped Film Corner: Common in the premolar area, where the film isn't level
◦ Incorrect Centering: The area of interest must be in the center of the film
• Film Bending: Excessive bending to adapt the film to the mouth causes black lines or distortion, especially in the canine area
• Angulation Errors:
◦ Vertical Angulation: Incorrect angles lead to elongation (flat angle) or foreshortening (steep angle)
◦ Horizontal Angulation: Causes horizontal overlap, making it impossible to see interproximal areas
4. Exposure Errors
• Cone-cut: Occurs when the X-ray beam doesn't cover the entire film, appearing as a curved white area
• Blank Film: Results from no radiation exposure (e.g., machine not on)
• Black Film: Results from exposure to white light
• High Density (Dark Film): Caused by overexposure (high kV, mA, or time) or using fast film with slow settings
• Low Density (Light Film): Caused by underexposure or short development time
5. Processing Errors
• Reticulation: Cracked appearance of the emulsion due to extreme temperature changes between developer and water
• Chemical Contamination: Black spots from developer drops or white spots from fixer drops before processing
• Stains: Yellowish-brown discoloration occurs due to exhausted chemicals or insufficient washing under running water
• Cut-offs: Developer cut-off appears as a straight black/white line when the film isn't fully submerged
• Physical Damage: Overlapped films in the hanger, fingerprints from handling wet films, or scratches from rough handling
6. Fogging
: Fogging produces a hazy, unclear image where details are lost
. It can be caused by:
• Light/Radiation: Light leaks in the darkroom, incorrect safe lights, or storing films near the X-ray machine
• Chemical/Storage: Using exhausted developer, poor ventilation (chemical fumes), or storing films in high heat and humidity

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