All About Radiographic Faults
Projection Errors
- Fault: Apical ends of teeth are cut off
- Reason: Film is placed too close to the teeth in maxillary arch in paralleling technique
- Rectification: Place the film away from teeth
- Reason: Decreased vertical angulation
- Rectification: Increase the vertical angulation
- Reason: Improper positioning of film in oral cavity
- Rectification: Not more than 1/8th inch of the film edge should extend beyond the incisal-occlusal surface of teeth
- Fault: Overlapping of teeth
- Reason: Plane of the film not parallel to the lingual surface of teeth
- Rectification: Film should be placed parallel to the lingual surface of teeth
- Reason: Incorrect horizontal angulation of the cone
- Rectification: Central ray of the X-ray beam should be directed perpendicular to the facial surface of teeth
- Fault: Occlusal plane appears tipped or tilted
- Reason: Edge of film not placed parallel to the incisal-occlusal surface of the teeth
- Rectification: Edge of film should be parallel to the incisal-occlusal surafce
- Reason:Film not holded properly by patient if finger holding method is used
- Rectification:Instruct the patient to hold the patient correctly
- Fault: Specific region is not showing
- Reason: Faulty film placement
- Rectification: Center the film over the teeth to be radiographed
- Fault: Crown of the teeth not showing
- Reason: Insufficient film below or above crowns of teeth
- Rectification: 1/8th of the film should extend below or above crown
- Reason: Decreased vertical angulation
- Rectification: Increase the vertical angulation
- Fault: Partial image
- Cone Cut
- Reason: Position Indicating Device not covering the area of intrest, not using film holder
- Rectification: Cone should be centered over the area of intrest and the film, both vertically and horizontally
- Reason: Upper edge of the film not immersed in the developing solution
- Rectification: Maintain the level of developing solution in the processing tank and make sure film is completely immersed during processing
- Distal Surface of canine not visible on bitewing film
- Reason: Bitewing film positioned too far posterior in the mouth
- Rectification: Antrior edge of bitewing film should be positioned at the midline of mandibular canine
- Third molar region not visible on the film
- Reason: Film is placed too far anterior in the mouth
- Rectification: Anterior edge of the film should be placed at the midline of mandibular secomd premolar
- Only a portion of film is exposed in panoramic films
- Reason: Film casette incorrectly positioned in the starting position
- Rectification: Place the cassette correctly
- Cone Cut
- Fault: Shape Distortion
- Forshortening
- Reason: Increased vetical angulation in bisecting angulation technique
- Rectification: Reduce the vertical angulation
- Reason: Film not placed parallel to long axis if teeth in paralleling technique
- Rectification: Film should be placed parallel to the long axis of teeth
- Elongation
- Reason: Decreased vertical angulation in bisecting angle technique
- Rectification: Increase the vertical angulation
- Reason: film not placed parallel to long axis if teeth in paralleling technique
- Rectification: Film should be placed parallel to the long axis of teeth
- Distorted Image
- Reason: Film is bent as patient bites on the film holder
- Rectification: Use a film backing
- Reason: Negative vertical angulation ised in bitewing technique
- Rectification: Always use +10 degree vertical angulation with bitewing radiograph
- Overlapped Contacts
- Reason: Central rays not directed through the interproximal spaces
- Rectification: Central rays should be directed through interproximal spaces
- Magnification
- Reason: Increased film to object distance
- Rectification: Use recommneded film to object distance
- Reason: Pointed conical cone used which produces divergent beam
- Rectification: Use open ended lead lined cones
- Forshortening
- Fault: Herring Bone Effect or Tyre Track Appearance
- Reason: Back side of film with the lead foil placed facing towards the cone
- Rectification: Place the front side of film towards the cone
- Fault: Black dot in the film in apical area
- Reason: Identifying mark on the film towards the apical area of teeth
- Rectification: Place the raised dot on the film towards the occlusal or incisal surface of teeth
- Fault: Artifacts on Radiograph
- Writing lines on radiograph
- Reason: Writing on the film pocket with ball pen or lead pencil
- Rectification: Use a marker pen to write on film pocket
- Black lines on the radiograph
- Reason: Bending of the film to reduce patient discomfort
- Rectification: Avoid bending of film
- Random Artifacts on Film
- Reason: Contaminants (paper,dust will prevent the X-ray from reaching the film
- Rectification: Clean the screens inside the cassette
- Writing lines on radiograph
- Fault: Double Images on Radiograph
- Reason: Film exposed twiced to radiation
- Rectification: Place exposed films in separate labelled compartment
- Fault: Blurred Image on Radiograph
- Reason: Movement of the film, patient or tube during exposure
- Rectification: Use film holders
- Reason: Double exposure
- Rectification: Place exposed films in separate labelled compartment
- Fault: Radiopaque Artifacts on Radiograph
- Reason: Dental appliance or foreign bodies in or area near to the radiograph
- Rectification: Ask the patient to remove dental appliance or any foreign bodies (Eg. eye glasses, nose ring, ear ring etc.)
- Fault: Adumbration (Cervical Burn Out)
- Reason: Horizontal angle of beam is not directed through the contact area of teeth
- Rectification: Horizontal angle of beam should be redirected through contact area of teeth
Exosure and Processing Errors
- Low Density Film (Light Radiograph)
- Under Exposure
- Reason: Short exposure time
- Rectification: Set exposure time correctly
- Reason: Increased source to film distance
- Rectification: Maintain proper source to film distance
- Reason: Low kVp
- Rectification: Increase kVp by approximately 5kVp
- Reason: Reduced mA
- Rectification: Increase mA or exposure time
- Reason: Film packet placed with wrong side facing the tooth causing the image of lead superimposed on the object image
- Rectification: Place the pebbled side of film facing the tooth towards cone
- Reason: Incorrect film screen combination used
- Rectification: Always use right screen combination
- Under development
- Reason: Less developing time
- Rectification: Set darkroom time correct
- Reason: Low developer temperature
- Rectification: Raise temperature to 70 degree F
- Reason: Exhausted or contaminated or diluted developer
- Rectification: Replace or replenish the developing solution
- Reason: Excessive fixation
- Rectification: Regulate time for fixing as per time table
- Under Exposure
- Fault: High density film (Dark Radiograph)
- Exposure parameters
- Reason: Exposure time too long
- Rectification: Set timer correctly or reduce exposure time
- Reason: Increased kVp
- Rectification: Reduce the kVp
- Reason: Decreased source film distance
- Rectification: Measure the source film distance and adjust the exposure time accordingly
- Reason: Inaccurate time
- Rectification: Check the timer
- Reason: Increased mA for given exposure
- Rectification: Reduce kVp or exposure time
- Over development
- Reason: Increased developing time
- Rectification: Use time temperature method with darkroom timer
- Reason: Increased developer temperature
- Rectification: Lower temperature to 70 degree F
- Reason: Concentrated developing solution
- Rectification: Check mixing instructions
- Reason: Inadequate fixation
- Rectification: Fixation time should be standardized as per instructions
- Reason: Accidental exposure to light or improper safe light
- Rectification: All darkroom procedure should be done in safelight
- Exposure parameters
- Fault: High Contrast
- Reason: Insufficient penetration
- Rectification: Increase kilo voltage
- Reason: Over development
- Rectification: Use time temperature method
- Reason: High contrast films or intensifying screens
- Rectification: Use lower contrast film or slower speed screens
- Reason: Inaccuarte timer
- Rectification: Correct the timer
- Fault: Low Contrast
- Reason: Excessive penetration
- Rectification: Decreased kilo voltage
- Reason: Under development
- Rectification: Set dark room timer correctly. Raise temperature to 70 degree F.
- Reason: Films with insufficent contrast and cassettes with slow intensifying screens
- Rectification: Use higher contrast films or higher speed screens
- Reason: Scatterred radiation
- Rectification: Use suitable cone
- Reason: Under exposure
- Rectification: Check exposure time
- Fault: Fog
- Reason: Light streaks in darkroom or improper safe lights
- Rectification: Use recommended safe lights and check darkroom for any light leaks
- Reason: Turning on white light too early
- Rectification: Fix film for 2 minutes before turning on the white light
- Reason: Prolonged exposure to safe light
- Rectification: Reduce exposure of films to safe light
- Reason: Smoking in the dark room
- Rectification: Avoid smoking in darkroom
- Reason: Developer with high temperature, concentrated or contaminated
- Rectification: Check temperature, concentration and tanks of developer solution
- Reason: High humidity of storage area
- Rectification: Store films in a dry place with 50% relative humidity
- Reason: Out dated film
- Rectification: Use older film first
- Reason: Unused films exposed to radiation
- Rectification: Store unexposed films in lead container
- Fault: Streaks on film
- Reason: Failure to agitate during development
- Rectification: Agitate films on immersing them in the developer
- Reason: Chemical deposits on hanger clips
- Rectification: Keep hanger clips clean
- Reason: Excessive drying temperature
- Rectification: Reduce air flow over films
- Reason: Insufficient fixing
- Rectification: Fixing time should be twice the developing time
- Reason: Contaminated water used to wash films
- Rectification: Wash films under clean running water
- Fault: Blister of films
- Reason:Unbalanced processing temperature
- Rectification: Control the temperature of water bath
- Reason: Excessive acidity of of fixer
- Rectification: Replace the fixing solution
- Reason: Films not agitated when immersed in fixer
- Rectification: Agitate the film during fixing
- Fault: Reticulation (Orange peel appearance)
- Reason: Sudden extreme temperature changes in processing
- Rectification: Maintain uniform processing temperature
- Reason: Weakened fixer solution
- Rectification: Replenish or replace fixer solution
- Fault: Frilling
- Reason: Hot processing solution
- Rectification: Maintain 70 degree F processing temperature
- Fault: Air bells
- Reason: Air bubbles trapped on film surface preventing uniform reduction of the emulsion
- Rectification: Agitate film into developer
- Reason: Dust present on the film or screen
- Rectification: Keep darkroom clean and periodically clean the screens
- Reason: Emuslsion tear due to rough handling of film
- Rectification: Dont rub the film against the side of tanks or other film hangers
- Reason: Film contminated with fixer before developing
- Rectification: Keep the dark room clean and dry
- Reason: Excessive bending of film
- Rectification: Handle the films gently
- Reason: Crack in intensifying screens
- Rectification: Replace the intensifying screens
- Fault: Black spots on films
- Reason: Dust in contact with underdeveloped films
- Rectification: Prevent fine particles of developer coming in contact with the films
- Reason: Film splashed with the developer before placing in developing tank
- Rectification: Careful handling of solution and clean work area
- Reason: Films touching during developing
- Rectification: Films should not touch the processing tank
- Reason: Black wrapping paper sticking to film surface Rectification: Remove the black paper carefully woith dry hands
- Reason: Excessive bending of film due to cutvature of hard palate or excessive finger pressure applied on film Rectification: Check the film placement before exposure. Instruct the patient to hold the film gently. In case of hard palate curvature cotton rolls are used withb paralleling technique
- Reason: Finger contaminated due to developer
- Rectification: Wash hands properly
- Reason: Fingernail artifact
- Rectification: Avoid long nails during film processing
- Fault: Artifacts from processing
- Reason: Black cresent due to rough film handling
- Rectification: Handle films by edges only
- Reason: Black smudge marks due to finger prints
- Rectification: Use dry finger while handling film
- Reason: Black lines due to static electricity
- Rectification: Install electric humidifier or cool vapor vaporizers in dark room
- Reason: Film creasing or film emulsion cracks causing thin radiolucent line on radiograph
- Rectification: Dont bend the film excessively
- Fault: Stains on film
- Yellow or Brown stains
- Reason: Contaminated or oxidized developer or prolonged development
- Rectification: Use fresh developing solution and recommended developing time
- Reason: Insufficient rinsing
- Rectification: Rinse films for 15-20 seconds under clean running water
- Reason: Contaminated fixer solution
- Rectification: Use fresh fixer solution
- Dichoric radiograph (Two colors)
- Reason: Old or contaminated developer or fixer
- Rectification: Use fresh and clean developer and fixer
- Reason: Film partially fixed in weak fixer , exposed to light and washed
- Rectification: Replace fixer solution and follow recommended processing cycle
- Reason: Prolong intermediate rinse in contaminated water
- Rectification: Use fresh running water
- Yellow or Brown stains
- Fault: Deposits on film
- Reason: Exhausted / Contaminated solution and rinsing water
- Rectification: Use fresh solution and clean running water
- Reason: Solution not mixed in correct proportion
- Rectification: Follow manufactureres instruction for solution preparation
- Fault: Clear Film
- Reason: Film not exposed
- Rectification: Failure to switch on the X-ray machine or machine malfunction
- Reason: Exposed film first put into the fixing solution
- Rectification: Positions of processing tanks should be fixed and labelled
- Fault: Black Film
- Reason: Film exposed to light
- Rectification: Exposed and unexposed film should be kept in seprate labelled container
- Fault: Brittleness of finished radiograph
- Reason: Excessive drying temperature
- Rectification: Reduce dryer temperature
- Reason: Excessive drying time with high humidity
- Rectification: Reduce the drying time. Use wetting agent prior to placing the films in dryer
- Reason: Excessive fixer acidity
- Rectification: Replace fixer solution
- Fault: Faded image on finished radiograph (Radiopaque appears Radiolucent)
- Reason: Exhausted fixer or inadequate fixing or final wash
- Rectification: Follow proper fixing guidelines
- Fault: Dark flow marks
- Reason: Vigorous agitation producing solution currents
- Rectification: Agitation should be done gently
- Reason: Weak developer or high temperature of developing solution
- Rectification: Follow proper developing guidelines
- Fault: Emulsion Peel
- Reason: Abrasion of film during processing
- Rectification: Handle the film with utmost care
- Fault: Grainy appearance
- Reason: Developing solution too warm
- Rectification: Follow developing solution guidelines
- Fault: Vertical white lines on panoramic radiograph
- Reason: Push button on exposure is accidently released and pressed down for remainder of excursion resulting in a blank space on radiographas radiation to film is cut off
- Rectification: Press the exposure button till exposure cycle
Automatic Processing Errors
- Fault: Film Density Errors
- Reason: Decrease in film density due to low developer temperature, exhausted or contaminated developer or no agitation in developer tank
- Rectification: Drain and clean tank, install new developer
- Reason: Processing too fast
- Rectification: Follow processing guidelines
- Reason: Increase in film density due to high developer temperature
- Rectification: Decrease the developer temperature
- Reason: Light leak in processor cover Rectification:
- Reason: Streaking due to rollers and crossovers encrusted with chemical deposit Rectification: Clean them periodically
- Reason: Fogged films due to contaminated solution, processor or dark room light leaks, excessive developer temperature
- Rectification: Use clean solution, prevent light leaks and lower the developer temperature
- Fault: Film Drying Errors
- Reason: Depleted fixer or insufficient water flow
- Rectification: Install new fixer solution and check water flow
- Reason: Low dryer temperature or dryer thermostatic control is not working
- Rectification: Check the temperature settings
- Reason: Chemical imbalance
- Rectification: Replace with new solution
- Reason: Improper type of film for time cycle of processor
- Rectification: Check on the automatic processor manual for type of film
- Fault: Abnormal film surface marks
- Peeling of Emulsion
- Reason: Developer temperature too high
- Rectification: Reduce developer temperature
- Reason: Improper fixer strength
- Rectification: Replace fixer solution
- Reason: Heavy developer deposits on developer rack rollers above solution level
- Rectification: Keep cleaning the machine
- Reason: Improper film
- Rectification: Check the type of film used for particular machine
- Reason: Rough handling of films
- Rectification: Handle films gently
- Pressure Marks
- Reason: Foreign material or rough spot on roller
- Rectification: Clean the rollers
- Reason: Excessive pressure over films
- Rectification: Handle films gently
- Clody or smudgy film appearance
- Reason: Depleted fixer
- Rectification: Replace the fixer solution
- Reason: Improper type of film used
- Rectification: Use recommneded type of film
- Reason: White cloudy appearance on film due to no water in water tank
- Rectification: Check water level
- Scratches on film surface
- Reason: Foreign materials on rollers
- Rectification: Clean the rollers
- Reason: Improper handling of film
- Rectification: Handle films gently
- Reason: Damaged or defective films
- Rectification: Check the films before use
- Reason: Stalled or sticking roller
- Rectification: Inspect racks, gears and gear mesh
- Drying pattern on film surface
- Reason: Dryer too hot
- Rectification: Reduce dryer temperature
- Dark spots or lines on film surface
- Reason: Excessive roller pressure
- Rectification: Get the processor serviced
- Reason: Dirty rollers in the processors
- Rectification: Clean rollers carefully
- Reason: Contamination of film by dirty working area
- Rectification: Clean the working area
- Film Discolorations
- Reason: Fixer in developer and too fast processing gives brown stains
- Reason:Shiny films due to excessive hardening
- Peeling of Emulsion