Midterm Lesson 2 Flashcards
any appearance/opacity on a radiograph which doesn’t represents an actual anatomic structure within the patient being radiographed.
Undesirable optical densities or blemishes on a radiograph or any other medical image.
Artifacts
Impacts of an Artifact on a Film
Degrades the quality of radiograph and effect interpretation.
Cause visual distractions for the radiologist leading to misinterpretations of an actual anatomic structure.
Can mimic pathology
Types of Radiographic Artifacts
~ Pre-Exposure
a. Exposure Artifacts
b. Processing Artifacts
~ Positioning
c. Handling & Storage Artifacts
~ Post-Exposure
Type of artifact that is usually easy to detect and correct.
Exposure Artifacts
Types of Exposure Artifacts
Foreign Object Artifacts
Double Exposure
Motion
Poor Screen-Film Contact
Positioning Errors
Radiopaque materials superimposed the patient anatomy
Foreign Object Artifact
- Two separate images in one radiograph
- Reuse of cassette that is already exposed
Double Exposure
- Blurred image or poor quality radiograph
- E.g breathing, involuntary movements
Motion
How to prevent motion artifacts from?
- Restrain – pediatrics
- Sedation
- Proper and clear instruction
Poor quality (blurring of image) and obscures the detail of the image
Due to warped cassette
Poor Screen-Film Contact
Three types of Positioning Errors
> Improper Patient Rotation
> Distortion
> Upside-down Cassette
misinterpretation of either size or shape of the anatomic part
Distortion
Types of Distortion
Elongation
Foreshortening
refers to the image of the object that appears longer than the true object
Elongation
refers to the image of objects that appear shorter than the true object
Foreshortening
Image appears underexposed
Upside-down Cassette
Types of Processing Artifacts
a) Guide shoe marks
b) Pi lines
c) Dichroic Stain or “Curtain Effect”
d) Wet Pressure sensitization
e) Emulsion Pick off
occur when the guide shoes in the turnaround assembly of the processor are sprung or improperly positioned
Guide shoe marks
occur at 3.1416-inch (π) intervals because of dirt or a chemical stain on a roller, which sensitizes the emulsion.
Because the rollers are 1 inch in diameter, 3.1416 inches represents one revolution of a roller.
Pi lines
caused by improper squeezing of processing chemicals from film
appears as a curtain effect on the radiograph
Dichroic Stain or “Curtain Effect”
a term that is generally applied to all chemical stains (chemical fog)
Dichroic Stain
means two color
Dichroic
common artifact that is produced in the developer tank.
Irregular or dirty rollers cause pressure during development and produce small circular patterns of increased OD.
Wet Pressure sensitization
Dirty or warped rollers which result in sludge deposits on the film.
artifact caused by little pieces of emulsion that stick to the rollers and is picked off by a passing film.
Emulsion Pick off
Types of Handling and Storage Artifacts
a) Light Leak
b) Radiation fog
c) Storage fog
d) Pressure or Kink Marks
e) Scratches
f) Static Artifacts
g) Hypo retention Stain
h) Finger marks
- a form of fog
- Cassette is not closed properly.
- Film bin/box left open.
- Safelight cracks.
Light Leak
The film bin is inadequately shielded from radiation.
- The film has been left in the x-ray room during other exposures.
Radiation fog
- Outdated film
- Darkroom/storage room is too high.
Storage fog
Prevention of storage fog
FIFO – First in, first out
- The film is improperly or roughly handled.
- The film is stacked too high in storage (the weight causes marks).
Pressure or Kink Marks
It is caused by the kinking or abrupt bending of film. Both events usually appear as increased OD.
Kink Mark
(Small) White lines appear on the film due to careless handling of film.
Looks like nail clippings
Scratches
It is caused by the buildup of electrons in the emulsion and is most noticeable during the winter and during periods of extremely low humidity.
Static Artifacts
Three Distinct Patterns of Static Artifact
a. Crown
b. Tree
c.Smudge
The yellow-brown stain that slowly appears on a radiograph after a long storage time indicates a problem with hyporetention from the fixer.
Hypo retention Stain
How to prevent fingermarks on the film?
Keep fingers dry and clean. Touch only film edges
