Radiographic errors

RADIOGRAPHIC ERRORS AND ARTIFACTS

Quality Evaluation Criteria
1. All radiographs must have acceptable image (details, definition, density & contrast). 2. All crowns and roots including apices are fully depicted together with interproximal alveolar crests, tooth contact areas, and surrounding apical bone regions. 3. Image of all teeth and other structures are shown in proper relative size and contour with minimal distortion and without overlapping images, where anatomically possible. 4. The radiograph is free from film handling and processing errors.

Bitewing Radiography Evaluating Criteria:

1. The interproximal contacts should not be overlapped from the distal surface of the canine to the mesial surface of the third molar, to the extent that interpretation is impossible. 2. The crown of the maxillary and mandibular teeth should be centered in the image from top to the button. 3. The crest of alveolar bone should be visible with no superimposition of the crowns of adjacent teeth. 4. The occlusal plane should be as horizontal as possible. 5. The buccal and lingual cusps should not be excessively separated.

Films with errors should be avoided due to the following reasons:

Retake will lead to: Expose the patient to unnecessary radiation. Waste film & time (money). Interfere with accurate interpretation and diagnosis.

Types of Artifacts

Technique Artifacts. Exposure Artifacts. Processing Artifacts.



Techniques Artifacts

A. Patient Preparation Errors: 1.Radiopaque artifact

Appearance: as radiopaque artifact superimposed over the dental image. Cause : Dental appliances left in the mouth during exposure, jewelry & eye glasses. Correction : all this items should be removed before placing of the film.
Techniques Artifacts

Removable Partial Denture

Complete Denture

Appearance: Blurred image appears on the film. Cause: 1.The patient move during exposure of the film. 2.Movement of the tube. 3. Movement of the film. Correction : stabilize the patients head, tube, and film, before exposing the radiograph.
2.Blurred Images
Techniques Artifacts

B. Film Placement Error.

Apices Cut-off. Insufficient vertical angulation. The film is not positioned apically enough.
Techniques Artifacts

1.Apices Cut-off Appearance: Absence of apical structures & no apices appear on the film. Cause: the film is not positioned in the patients mouth to cover the apical regions of the teeth. Correction: make sure that no more than 1:8 inch of the film edge extend beyond the incisal -occlusal surfaces of the teeth such film placement ensure adequate coverage of the tooth apices.
Techniques Artifacts

2. The crowns of teeth not shown

Techniques Artifacts


3. Reversed film
Techniques Artifacts

3.Reversed Film Appearance: light image with a herringbone pattern or tire-track, appearance of the film. Cause: The film is exposed from non-exposed side. The x-ray beam is attenuated by the lead foil backing in the film packet . Correction: always place the white side of the film adjacent to the teeth.
Techniques Artifacts

4. Dot Artifact.

Techniques Artifacts

5. Double Image

DOUBLE EXPOSURE Appearance: a double image appear on the film. Cause: the film is exposed twice. Correction: separate exposed and unexposed films.
Techniques Artifacts

6. Tongue or Finger Artifact.

Techniques Artifacts

7.Dropped film corner

The film edge is not placed parallel to the occlusal surface of the teeth.
Techniques Artifacts

8.Area of interest not shown

This is the result of not placing the film to cover all the teeth in the area of interest and not centralizing the film over the area of interest.
Techniques Artifacts


9.Black line
Due to excessive bending of the film prior to its placement inside the patient’s mouth (pressure causes ionization of silver halide upon processing will be darker). Techniques Artifacts

C. Overlapping Errors

Techniques Artifacts

1.Incorrect horizontal angulation

Appearance: overlapped contacts appear on the film. Cause: the central ray is not directed through the interproximal spaces. As a result the proximal surfaces of adjacent teeth appear overlapped in the periapical film and this prevent the examination of interproximal areas this error occurs with both the paralleling and bisecting techniques. Correction: direct the x-ray beam through the inter proximal regions.
Techniques Artifacts

D. Shape Distortion Errors

1. Shortening
Appearance: short teeth with blunted roots appear on the film. Cause: The vertical angulation is excessive. This error occurs with the bisecting techniques Correction: prevent excessive vertical angulation with the bisecting technique.
Techniques Artifacts

2. Elongation

Appearance: long distorted teeth appear on the film. Cause: the vertical angulation is insufficient (decrease) therefore the image appears longer than the actual teeth. This error occurs with the bisecting technique Correction: use adequate vertical angulation with the bisecting technique.
Techniques Artifacts

3. Film Distortion

FILM BENDING Appearance: images appear stretched and distorted. Cause: the film is bended excessively owing to the curvature of the hard palate or heavy finger pressure on the film. Correction: check the film placement before exposure, instruct the patient to stabilize the film gently, in case of curvature of hard palate cotton rolls can be used also film holding device is helpful in preventing film bending .
Techniques Artifacts


E. Cone-Cut.
Appearance: as a clear area with curved outline . Cause: If the PID (Positioning-Indicating Device )is misaligned and the x-ray is not centered over the film, a partial image is seen on the resultant radiograph, this partial image is called cone-cut. .
Techniques Artifacts

Exposure Artifacts

A. Film exposure Errors
1.Blank Image: a film that has receive no radiation will have no image & will appear clear film, due to: The x-ray machine is not turned on. The operator had completely failed to align the x-ray PID with the film. The operator may not press the timer button properly to activate the exposure. The film not exposed at all, while another is used twice & produce double image.
Exposure Artifacts

2.Film Exposed to Light Appearance: the film appears black. Cause: the film accidentally exposed to white light. Correction: -Do not unwrap the film in a room with white light . -Check the dark room for possible light leaks . -Use safe light only during processing.
Exposure Artifacts

B.Time and Exposure Factor Problems

1.Over exposed film Appearance: the film appears dark. Cause: excessive exposure time ,KvP ,mA ,or a combination of these factors Correction: check the exposure time ,KvP, mA ,settings on the x-ray machine before exposing the film.
Exposure Artifacts

2.Under exposed film Appearance: the film appears light. Cause: inadequate exposure time ,KvP, mA ,or a combination of these factors. Correction: check the exposure time, KvP, mA, settings on the x-ray machine before exposing the film.
Exposure Artifacts

Processing Artifacts

Processing Artifacts
Time and temperature errors. Chemical contamination errors. Film handling errors. Lighting errors.

A.TIME AND TEMPERATURE

1.Under developed film Appearance: the film appears light (faint). Cause: Inadequate developing time. Inaccurate timer. Low developer temperature. Inaccurate thermometer. Depleted or contaminated developer solution.
Processing Artifacts


2.Over developed film Appearance: the film appears dark. Cause: Excess developing time. Inaccurate timer. High developer temperature. Inaccurate thermometer. Concentrated developer solution.
Processing Artifacts


3.Reticulation of emulsion Appearance: the film appears cracked. Cause: the film is subjected to a sudden temperature change between the developer and water bath. Correction: check the temperature of the processing solutions and water .bath Avoid drastic temperature differences between the developer and water bath.
Processing Artifacts

B.CHEMICAL CONTAMINATION

1.Developer spots Appearance: dark spots appear on the film. Cause: developer solution comes in contact with the film before processing. Correction: use clean work area in the dark room. To ensure clean working surface ,place a paper towel on the work area before unwrapping films.
Processing Artifacts



Appearance: the film appear yellowish-brown. Cause: 1.exhausted developer or fixer. 2.Insufficient fixation time. 3.Insufficient rinsing. Correction: replace depleted developer and fixer solutions with fresh one. Make sure that the film have adequate fixation and rinsing time. Rinse processed film for 20 m in circulating cold water.
2.Yellow-brown stains
Processing Artifacts


3.Deposits on the film: chemical precipitants that adhere to the film due to contamination, improperly prepared, or exhausted solutions, unclean film hanger clips.
Processing Artifacts


4.Fixer spots Appearance: white spots appear on the film. Cause: fixer solution come in contact with the film before processing. Correction: use clean work area in the dark room. Place a paper towel on the work area before unwrapping films.
Processing Artifacts

Film Handling Artifacts

A. Pressure Marks.
1. Finger print impression
Film Handling Artifacts



1.Fingerprint artifact Appearance: black fingerprint appears on the film. Cause: the film is touched by fingers contaminated with developer. Correction: wash and dry hands before processing films. Work in a clean area. Handle the film by the edges only.
Film Handling Artifacts

2.Finger nail marks

Film Handling Artifacts


2.Fingernail artifact Appearance: black crescent-shaped marks appear on the film. Cause:the film emulsion is damaged by the operators finger nail during rough handling of the film. Correction: gently handle the film by the edges only.
Film Handling Artifacts

3.Bend Marks. (black line marks)

Film creasing Appearance: a thin radiolucent line appears on the film. Cause: the film is creased and the film emulsion cracked . Correction: do not bend or crease the film excessively instead gently soften the corners of the film before placing in the patients mouth.
Film Handling Artifacts


4.Static electricity Appearance: thin, black branching lines appear on the film. Cause: opening a film packet quickly. Opening a film packet before touching another object such as the film processor. It occurs most frequently during period of low humidity. Correction: open film packets slowly. Touch a conductive object before unwrapping films.
Film Handling Artifacts

Film Handling Artifacts

5. Film Fog: Appears as a dull-gray low contrast image due to: Use of out dated film. Improper film storage. Radiation before & after exposure. Improper safelight condition. Higher developing solution temperature. White light leaks in the dark room.

Correction: check the filter and bulb wattage of the safe light. Check the dark room for light leaks.
Film Handling Artifacts

Film Handling Artifacts

6.Black Streaks: Fixer contaminated hanger clips. Insufficient fixing solution or improper rinsing. Dirty rollers in automatic processors.
Film Handling Artifacts


7.Overlapped films Appearance: white or dark areas appear on films where overlap has occurred. Cause: when two films come into contact with each other during manual or automatic processing techniques. Films that overlap in developer are white, while that overlap in fixer are black . Correction: make sure that the films was not come into contact with each other during processing.
Film Handling Artifacts



8.Air bubbles Appearance: white spots appear on the film. Cause: air is trapped on the film surface after the film is placed in the processing solution. Air bubbles prevent the chemicals from affecting the emulsion in the area. Correction: gently agitate and stir film racks after placing them in the processing solution.
Film Handling Artifacts


9.Scratched film Appearance: white lines appear on the film. Cause: the soft film emulsion is removed from the film base by a sharp object such as film clip or film hangers. Correction: use care when placing a film rack in the processing solutions. Avoid contact with other film hangers.
Film Handling Artifacts

10.Developer cut off

Appearance: a straight white border appears on the film Cause: low level of developer solution that represents an under developed portion of the film. Correction: check the developer level before processing films. Make sure that all the film parts are completely immersed in the developer solution. .
Film Handling Artifacts


Appearance: a straight black border appears on the film. Cause: low level of fixer solution that represents an unfixed portion of the film. Correction: check the fixer level before processing films . Make sure that all the film parts are completely immersed in the fixer solution.

11.Fixer cut off

Film Handling Artifacts

LIGHTING ERRORS

Light leak Appearance: the exposed area appears black. Cause: accidental exposure of the film to white light. Torn film packets that expose a portion of the film to light. Correction: examine film packets for minute tears or defects before use. Never unwrap films in the presence of white light.


Film too dark Possible causes• Overexposure owing to:— Faulty X-ray equipment, e.g. timer— Incorrect exposure time setting by theoperator• Overdevelopment owing to:— Excessive time in the developer solution— Developer solution too hot— Developer solution too concentrated• Fogging owing to:— Poor storage conditions:* Allowing exposure to stray radiationToo warm— Old film stock i.e. films used after expirydate— Faulty cassettes allowing ingress of straylight— Faulty darkroom processing unit:* Allowing leakage of stray light* Faulty safe-lightThin patient tissues.

Film too palePossible causes• Underexposure owing to:— Faulty X-ray equipment, e.g. timer— Incorrect exposure time setting by theoperator— Failure to keep timer switch depressedthroughout the exposure• Underdevelopment owing to:— Inadequate time in the developer solution— Developer solution too cold— Developer solution too dilute— Developer solution exhausted— Developer contaminated by fixer• Excessive thickness of patient's tissues• Film packet back to front (film also marked

Film with inadequate or low contrastPossible causes• Processing error owing to:— Underdevelopment (film also pale)— Overdevelopment (film also dark)— Developer contaminated by fixer— Inadequate fixation time— Fixer solution exhausted• Fogging owing to:— Poor storage conditions:* Allowing exposure to stray radiation* Too warm— Poor stock control and film used afterexpiry date— Faulty cassettes allowing the ingress of stray light— Faulty darkroom processing unit.

Image unsharp and blurred :Possible causes• Movement of the patient during the exposure• Excessive bending of the film packet during the exposure film• Poor film:screen contact within a cassette• Film type — image definition is poorer with indirect-action film than with direct-action.Speed of intensifying screens — fast screens result in loss of detailOverexposure — causing burn-out of the edgesof a thin objectPoor positioning in panoramic radiography

Film markedPossible causes• Film packet bent by the operator• Careless handling of the film in the darkroomresulting in marks caused by:— Finger prints— Finger nails— Bending— Static discharge• Processing errors owing to:— Chemical spots— Under fixation — residual silver halideemulsion remaining— Roller marks— Protective black paper becoming stuck tothe film— Insufficient chemicals to immerse films fully• Patient biting too hard on the film packet• Dirty intensifying screens in cassettes.

Operator positioning errorsTypical positioning faultsIntraoral radiographic positioning faults include:• Incorrect placement of the X-ray tube headproducing:— Elongation— Foreshortening— Superimposition:overlapping — Coning off or cone cutting • Incorrect placement of the film packet:— Back to front, image of the lead foil evident(film also too pale)— Inadvertently used twice, double exposure(film also too dark)— Not covering the area of interest