chapter 11 Technical Artifacts and Errors: Case Studies
Artifact: Anything that decreases the quality of the radiograph resulting in difficult evaluation and interpretation.
INTRODUCTION
Radiographic artifacts are a menace to any radiographer. A radiograph is often marred by artifacts resulting from a number of causes. An artifact not only decreases the quality of the radiograph but may also lead to a misdiagnosis. The radiographer is responsible for recognizing the error and correcting it. This chapter introduces the reader to many possible artifacts and challenges the reader’s ability to identify common film faults. Table 11-1 lists common artifacts and their causes. The radiographer should become familiar with this list and understand how to prevent these artifacts from occurring.
TABLE 11-1 COMMON ARTIFACTS AND THEIR CAUSES
| ARTIFACT | CAUSE |
|---|---|
| Film too dark | |
| Film too light |
Underdevelopment due to decreased temperature or time of development, developer exhausted or diluted
|
| Film gray/lack of contrast | |
| Lack of detail | |
| Heavy lines on radiograph (generalized) | |
| Inconsistent film density | |
| Black marks (not generalized) | |
| Clear areas on film (white marks;not generalized) | |
| Yellow radiograph |
If an artifact consistently appears on radiographs, the cassette should be isolated and the screens cleaned and examined for damage. If the fault is persistent, the cassette should be labeled “faulty screens.” However, if the damage could lead to a misdiagnosis, the screens should be discarded and replaced.
After examining the list of artifacts in Table 11-1, read through the following case studies and try to determine the cause and correction of the artifacts before looking at the answers.
EXAMINE THE RADIOGRAPH IN FIGURE 11-1
To minimize patient motion, a number of preventive measures can be taken. For example, motion can be limited by physical or chemical restraint. Sedation may be necessary for uncooperative patients or for views thatare difficult to position without patient compliance. In instances in which the patient is panting, holding the muzzle closed or giving a short, quick blow on the nose while simultaneously making the exposure can effectively stop rapid respiration temporarily. Another method to use is a short exposure time. This can be achieved by using the highest milliamperage possible setting on the x-ray machine and fast intensifying screens.
Another cause of a blurred radiographic image is x-ray tube or cassette motion. This problem occurs primarily in equine radiography, in which a standard x-ray table is not applicable. The cassette must be manually held next to the anatomic area of interest and the x-ray tube positioned on a portable stand. A sturdy tube stand and cassette holder (discussed in Part 2 of this text) can minimize this type of motion.
EXAMINE THE RADIOGRAPH IN FIGURE 11-2
If the processing solutions are expired or are too cold, or if the film is developed for an insufficient length of time, a radiograph such as the one in Figure 11-2 can result. Strict adherence to the standard processing procedure designated for the radiographic film being used and changing the solutions on a regular basis will prevent poor-quality radiographs.
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