Radiographic Errors and Artifacts PDF

12/11/2020 RADIOGRAPHIC ERRORS AND ARTIFACTS Dr. Walid Samir Salem BDS, MS, MHPE, PhD Assistant Prof., Oral Surgery Department Films with errors should be av...

12/11/2020 RADIOGRAPHIC ERRORS AND ARTIFACTS Dr. Walid Samir Salem BDS, MS, MHPE, PhD Assistant Prof., Oral Surgery Department 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. 1 12/11/2020 Causes of faulty radiograph The majority of the errors produced can be categorized into three groups: I. Technique & Projection errors. II. Exposure errors. III.Processing errors. I. Technique & Projection errors: a. Patient preparation error: Radiopaque artifact Blurred image Pressure mark b. Film placment artifact: Double image Reversed film Dot artifact Apices cut off Crown not shown Dropped film corner Area of interest not shown Black line Distortion 2 12/11/2020 c. Projection errors: Incorrect vertical angulation. Incorrect horizontal angulation PID alignment artifact Technique & Projection errors a. Patient preparation error Radiopaque artifact Dental appliances, body piercings, jewelry & eye glasses left in the mouth during exposure will appear as radiopaque artifact superimposed over the dental image. Correction: all this items should be removed before placing of the film. 3 12/11/2020 Periapical radiograph showing metallic artifact over the maxillary anterior bridge supported on maxillary canine. 4 12/11/2020 Technique & Projection errors a. Patient preparation error Blurred image Movement of the film, patient or X-ray tube head during exposure will result in a blurred image. Correction: the operator should explain for the patient & remind him to remain motionless during exposure. 5 12/11/2020 Technique & Projection errors a. Patient preparation error: Pressure mark Pressure from the incisal edge & cusps of the teeth (mostly in the pediatric occlusal radiograph). May appear black or white. Correction: ask the patient to bite gently. 6 12/11/2020 Technique & Projection errors b. Film placment artifact Double image When an exposed film is re-exposed the resulting film will have 2 superimposed images Correction: separate exposed from unexposed films Technique & Projection errors b. Film placment artifact Reversed film Low density with herring bone, tire-track or dotted pattern, as a result of directing the X-ray through the lead foil side of the film back. 7 12/11/2020 Technique & Projection errors b. Film placment artifact Dot artifact The identification (embossed) dot produce a circular radiolucent artifact on the final radiograph. This may interfere with interpretation of the apical areas of the teeth. Technique & Projection errors b. Film placment artifact Apices cut off Occur when the film is not positioned apically enough to record the entire tooth. Correction: leave only 2-3 mm beyond the occlusal plane 8 12/11/2020 Technique & Projection errors b. Film placment artifact Crown not shown There is no enough film extending occlusally. Correction: leave 2-3 mm beyond the occlusal plane. Technique & Projection errors b. Film placment artifact Dropped film corner The film edge is not placed parallel to the occlusal surface of the teeth. 9 12/11/2020 Technique & Projection errors b. Film placment artifact 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. Technique & Projection errors b. Film placment artifact 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). Correction: soften the corners of the film gently. 10 12/11/2020 Technique & Projection errors b. Film placment artifact Distortion Due to bending of the film to eliminate the patient’s discomfort specially in lower premolar area and upper central incisors. normal distortion Technique & Projection errors c. Projection errors Incorrect vertical angulation It will lead to: Elongated image due to insufficient v. angulation ( too flat), or Shortened image due to excessive v. angulation ( too steep) 11 12/11/2020 Technique & Projection errors c. Projection errors Technique & Projection errors c. Projection errors 12 12/11/2020 Technique & Projection errors c. Projection errors Incorrect horizontal angulation (Horizontal overlab) Is the appearance of the interproximal surfaces of the adjacent teeth over each other. This is due to improper H.A. due to improper alignment of the C.R. through the contact points i.e. not // to interproximal surfaces. Technique & Projection errors c. Projection errors 13 12/11/2020 Technique & Projection errors c. Projection errors PID alignment artifact If the PID 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. It appear as a clear area with curved outline. PID Film 14 12/11/2020 Aswan – Egy. II. Exposure errors. Blank image. Film exposed to light. High density image. Low density image. Image with high and low contrast. 15 12/11/2020 Exposure errors Blank image A film that didn’t receive radiation will have no image and will appear clear. The cassette of extra oral film is exposed backward Make sure the machine is turned on and listen for the exposure signal Film exposed to light Appearance: Film is black Do not unwrap the film outside the dark room 16 12/11/2020 Exposure errors High density image Causes:  exp. time  kv.  mA Decreased Target-Film distance Low density object High film speed Note that dark image may be due to over exposure or over developing 17 12/11/2020 Exposure errors Low density (faint) image Causes:  exp. time  kv.  mA Increased FFD High density object Low film speed To avoid these errors, check exposure time, kV, and mA before exposing the film 18 12/11/2020 III. Processing errors Film Handling errors: Chemical errors: Writing lines Light image. Developer cut off Dark image. Fixer cut off Blank image. Overlapped film Reticulation. Finger nail artifact Black spot or patch. Smudge. Black line. Scratched film White spot or patch. Saliva (moisture) Yellowish brown discoloration. contamination Static electricity 19 12/11/2020 Processing errors Chemical errors Reticulation When the film subjected to a sudden temperature change between the developer & water. Appear as cracked film. Processing errors Chemical errors Black spot or patch Developer contamination before immersion into the developer solution. 20 12/11/2020 Processing errors Chemical errors Black line Developer contamination processing hanger clips Dirty roller in automatic processor Processing errors Chemical errors White spot or patch Contamination with fixer before processing 21 12/11/2020 Processing errors Chemical errors Yellowish brown discoloration Exhausted solution or insufficient rinsing To avoid chemical contamination errors: Use a clean work area Place a clean paper towel on the working table before unwrapping the films Replace exhausted solutions with fresh ones Use adequate fixation time Wash for minimum 20 min 22 12/11/2020 Processing errors Film Handling errors Writing lines Appear on the radiograph due to writing on the film packet with ballpoint pen or lead pencil. It may appear black or white. Finger nail artifact Black or white crescent shape mark due to rough handling of the film. 23 12/11/2020 Processing errors Film Handling errors Developer cut off A straight blank white border due to underdeveloped portion. The film may not be completely immersed in the developer solution. Processing errors Film Handling errors Fixer cut off A straight black border. The film may not be completely immersed in the fixer solution. 24 12/11/2020 Processing errors Film Handling errors Overlapped film Film that overlap in developer are white, while that overlap in fixer are black Processing errors Film Handling errors Smudge (finger print) When the film touched by fingers contaminated with developer or fixer 25 12/11/2020 Processing errors Film Handling errors Scratched film White lines appear on the film due to careless handling of the film. Periapical radiograph showing White scratches due to -Removal of the emulsion by fingernails or metallic hangers due to careless handling -When the film is wet, the emulsion is swollen and weak. 26 12/11/2020 Saliva (moisture) contamination Saliva leak through the cardboard outer wrapping and cause sticking of the black paper on the film Correction: dry film packet from saliva before processing Processing errors Film Handling errors Static electricity Thin black branching lines Occurs when two surfaces are rubbed together against each other vigorously, this creates an electric charges with visible light emitted which is capable of exposing the x-ray film, thus leading to ionization of AgBr crystals at this area. Occur most frequently during periods of low humidity 27 12/11/2020 Lighting errors: light leakage Accidental exposure of the film to white light Appearance: Exposed area appear black Correction: examine film packets for defects before using Never unwrap films outside dark room 28 12/11/2020 Fogging Uneven cloudy appearance on the final image. Causes of fogging: * Light * Radiation.* Chemicals.* Storage. Light fogging: Due to 1. Leakage of light to the dark room. 2. Incorrect safe light  Wattage (15 watt)  No. (2)  Exposure (5 min) In adequate distance (6 feet) Improper filter (yellow, orange, red) 3. Use of neon light as normal light in the dark room. 29 12/11/2020 Radiation fogging: – Absence of lead foil backing lead to exposure of the film to secondary radiations. – Radiation leakage to stored films. Chemical fogging: – Exhausted developer. – Contaminated developer. – Exposure of film to chemical fumes. – Increased temperature and concentration of processing solutions. Fogging due to improper storage: – Expired films –  temperature of storage area. –  humidity 30