Artefacts could result from patients themselves, ranging from misinformation when they were scheduled for the examination, as in wearing deodorant or talc powder and lotion which should be avoided, movement during the examination, articles on their body overlying the breast during the examination , such as hair, jewelleries, hand, clothing, chin, and even the other breast Fig 1,2,3,4.

Figure 1

Figure 1: A cephalocaudal view showing a patient related artefacts caused by overlap of an object (fingers) in the lower medial quadrant of the breast.

Figure 2

Figure 2: A cephalocaudal view of the right breast showing a clothe artefact with roller artefact overlapping the upper inner quadrant of the breast

Figure 3

Figure 3: A mediolateral view showing the raised arms as an artefact in the upper medial quadrant and a scratch artefact

Figure 4

Figure 4: A mediolateral view showing the patient's chin as an overlying artefact in the upper medial quadrant and an artefact over the anterior margin of the breast.

Most artefacts caused by superimposed objects are readily identified and are easily corrected by repeating the exposure after first making sure that the overlapping object is safely out of the path of the x-ray beam ₂ .

Some of the artefacts were attributed to use of nail polish and hand lotions by the technician and faulty techniques by radiographers, such as choosing poor exposure factors or loading the film upside down.

Dark room artefacts encountered were due to darkroom faults, such as dirty intensifying screens, faulty or careless loading of films into cassettes, worn out cassette locks, bad dark room habits and cleanliness, poor chemical quality or mixing, use of cell phones and light leaks in the dark room.

The processing techniques are also an important factor in eliminating artefacts.

Initially, manual processing was the only mode of processing available in the department and the artefacts peculiar to this mode of processing is shown in Fig.5.

Figure 5

Figure 5: Mediolateral view of the left breast showing artefact due to manual processing and poor chemical admixture. The punctate opacity above and behind the nipple is grain or dust artefact

Improper developer fixation causes incomplete film fixing which leads to fading and brownish discoloration of the film, Fig 6.

Figure 6

Figure 6: A mediolateral view of the breast with artefacts due to improper developer fixation. Note the fading and brownish discoloration of the film.

This problem may be caused by loss of circulation in the fixer tank, under replenished or improperly mixed fixer, or low fixer temperature ₂ . Dust or grain artefacts (Fig 7), were the commonest seen artefacts on mammograms in our study as was found by other authors ₂,₅ .

Figure 7

Figure 7: Mediolateral view of the breast showing dust artefacts giving minus density particles on the film

These simulate calcifications. They are due to dust particles on the intensifying screen which prevent light from the intensifying screen from reaching the film. It is avoided by daily and weekly cleaning of the intensifying screen. Grain artefacts could also be as a result of sand particles in the water used in processing the films. The predominance of this type of artefact in our study is probably due to our source of water supply which is from the bore hole and is quite sandy.

Technologists should also not wear nail polish or hand lotion ₂,₅ , as these produce dust particles.

Figure 8

Figure 8: shows a bizarre artefact which usually occurs if film is loaded into a cassette before it dries. It is therefore recommended that the cassette should be air dried for at least 30 minutes before loading and wiped with a screen cleaning material and lint-free material to avoid minus density or pick-off artifacts , .

Figure 10

Figure 9: Mediolateral view showing fingernail prints. Fingerprints left after exposure show as a plus density (black) while those left before exposure will give a minus density (white).

Clumping of silver halide granules can also occur if the dryer is too hot and water droplets form during the drying process. It is recommended that the dryer temperature be set as low as possible while still producing films that are sufficiently dry when they exit the processor ₂ .

Washing the hands to rid them of grease and lotion prior to film handling and not allowing food and beverages in the darkroom help prevent fingerprint artefacts. Pressure artefacts can be caused by touching the film with the fingernails or fingertips or by improperly storing film boxes lying flat rather than standing on end. Fingernail marks are seen as plus-density or dark curvilinear artefacts, Fig 9.

Figure 11

Figure 10: A cephalocaudal view showing under penetration due to improper loading of film.

Fingertip pressure artefacts appear as minus-density oval artefacts that may be mistaken for a nodular lesion if seen on only one view. If repeated, neither artefacts should be present on the image ₂,₅ .

Loading films upside down or loading double film will cause underexposure ₂,₅ (Fig 10)

Figure 12

Figure 11a & b: Cephalocaudal views of the breast showing processor related plus density dark linear roller mark artefacts.

Mobile phones should not be used in the dark room as the light they show may cause film fog.

Some artefacts were due to faulty equipments such as poor compression, faults due to bad processor (mainly as a result of defects in the rollers). These types of artefacts were rarely seen in our study, most likely because these equipments were new. The processor related artefacts is usually due to worn out, uneven or erratic rotating rollers ₂ , excessive build up of developer on rollers or excessive roller pressure, as seen in Fig 11a and b.

Figure 13

Figure 14

Figure 12: Mediolateral view showing an artefact due to running films too close together through the processor.

Adequate processor cleaning, chemical replenishing and proper processor adjustment helps prevent this. Artefacts may also be due to running films very closely through the processor, (Fig 12) causing them to overlap and stick together, potentially ruining both film ₂,₅ .

Figure 15

Figure 13: Metallic artefacts due to compression equipment on a spot compression view

The compression component of the equipment is seen as a metallic artefact, Fig 13.

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