TOPIC: UNDIAGNOSTIC RADIOGRAPHY
🌟IMPORTANT POINTS TO REMEMBER
🔹Lighter radiographs: Radiographs exposed for less than optimum time or with less than optimum kVp or exposed for optimum timing and kVp but underdeveloped, all will result in lighter radiographs or low-density radiographs.
🔹Prevention can be done by developing such films for a relatively longer time
🔹Darker films: Radiograph exposed for more than optimum timing or with more than optimum kVp or exposed normally but developed for more time. Prevention can be done by immersing the film into the developing solution for less than optimum time
🔹Bending of film (black line): Distortion of the film emulsion along the linear angle.
🔹Phalangioma: Hold the film’ which is incorrect. When the film is developed, the image of the phalanx appears on the radiograph and superimposes the required image.
🔹Cone-cut/partial image: Improper alignment of the tube, the object and the film results.
🔹Blurring: It occurs due to movement of the film, the patient or the X-ray tube during exposure
🔹Image shape distortion: If excessive pressure is applied over the film, the central area of the film gets bent which results in distortion of the shape and size of the images.
🔹Tyre-track appearance: It occurs due to reverse film position.
🔹Ornamental artefacts: If any metallic object in the head, neck and face region are not removed, they may come across the pathway of the X-ray beam casting their shadows/images on the radiograph.
🔹Foreign body/restorative materials in the oral cavity: Any foreign body, or remnants of restorative materials lying in the buccal sulcus or the floor of the mouth.
🔹Double images resulting because of double exposure: If the same film is used for a second exposure in the same patient or the next patient, it results in double images.
🔹Improper horizontal angulation: Any deviation in the horizontal angulation results in the superimposition of mesial and distal surfaces of the adjacent teeth over each other, which will not provide any diagnostic information about their status leading to undiagnostic radiology.
🔹Accidental exposure of the film to the daylight: The resultant film after processing appears completely black.
🔹Contamination of film with developer or fixer solution before processing: Overdeveloping occurs in that area which appears darker/more black (radiolucent), which can get confused with the radiolucent lesions or periapical lesions if these artefacts coincide/superimpose over the periapical area.
🔹Contact with fixer: The part of the film in contact with the fixer solution does not contain any exposed silver halide crystals, and hence does not undergo a reduction process, resulting in a lighter area on the film.
🔹Film dropped into developer or fixer solution: If the film gets dropped into the developer solution, the film is overdeveloped (darker/black), if the film gets dropped/immersed into the fixer before developing, making the film clear and transparent.
🔹Film incompletely immersed in developer solution: Film that was not in contact with the developer, appears clear and transparent.
🔹Dust in developer solution: It results in light areas in the film.
🔹Film incompletely immersed in the fixer solution: Do not get cleared off resulting into yellowish-white appearance to the image in that area, which is undiagnostic.
🔹Dust in fixer: It results in yellowish-white areas in the film where it was stuck.
🔹Use of expired film: So if such films are used for exposure, during processing they may not get processed properly leading to a loss of image quality.
🔹Improper washing and storage of the film: Yellow stains develop on such films as the sulphur granules react with atmospheric oxygen to form H2S (hydrogen sulphide) which is yellow in colour and stains the film yellow, making it undiagnostic.
🔹Warping of the film: If the processed films are warped due to heat during storage, the gelatin of the film may get liquefied and the radiograph becomes undiagnostic.
🔹Improper positioning of the hanger: If it superimposes over the periapical area or an important part of an image, it results in an undiagnostic image.
🔹Scratches on film: Resulting in the development of clear (white) areas on the film.
🔹Improper drying: It produces stains on the film, which may obscure the image details making the film undiagnostic.
🔹Static electricity: It refers to the development of an electrical charge due to friction, which goes on exposing the processing black zigzag, grass root or tree-like appearance on the resultant radiograph.
📌MULTIPLE CHOICE QUESTIONS (MCQs)
💡 The only variable parameter in dental X-ray machines is
- Exposure time
- mA
- kVp
- All of the above
Answer: 1
💡 If the exposure time is less than optimum, the radiograph will appear comparatively
- Darker
- Lighter
- Complete black
- Will not be affected
Answer: 2
💡Underdeveloped radiograph will appear as a radiograph with
- High-density
- Lower density
- Unaltered
- Any of the above
Answer: 2
💡 Burn-out effect may be a result of
- Underdevelopment
- Lower kVp
- Higher kVp
- None
Answer: 3
💡Static electricity artefact is more common in
- Intraoral films
- Extraoral films
- Both
- None
Answer: 2
💡 In long-term storage, yellowish staining of films is due to
- Barium sulphide
- Hydrogen sulphide
- Sulphur dioxide
- Retention of water
Answer: 2
💡Clear and transparent film is the result if the film is dropped in
- Developer
- Fixer before developing
- Water
- None
Answer: 2
💡Overlapping of proximal contact areas is due to improper
- Vertical angulation
- Film placement
- Horizontal angulation
- None
Answer: 3
💡Reverse film placement causes
- Tyre-track appearance
- Fogging of film
- Cervical burnout
- Blurring
Answer: 1
💡 Improper alignment of the tube causes
- Phalagioma
- Cone cut
- Partial image
- Both b and c
Answer: 4