Answers to Self-Test Questions

Chapter 1

Radiograph A

1. Low contrast is present, because there is little variation between the soft tissue and bone radiographic densities.

2. This is a chest film; the low contrast makes the soft tissues of the lungs and heart more visible.

3. Yes. The film is positioned correctly for viewing the patient in anatomic position. The shadow of the heart to the patient’s left side verifies this.

Radiograph B

4. No. The film is not being viewed as if the patient is in anatomic position. The shadow of the heart should appear to the patient’s left.

5. The small oval-shaped area of increased density is likely to be of metallic composition, as can be inferred by its solid white radiographic density.

6. No. Without a lateral projection made at right angles to this anteroposterior projection, the depth of the location of the foreign object in the body cannot be determined. The object could represent a bullet lodged in a thoracic vertebra, or it could just as well represent a harmless medallion on a necklace resting on the skin.

Radiograph C

7. A barium contrast study of the gastrointestinal tract.

8. The technician forgot to have the patient empty his pockets. Fortunately, the area of interest was not obscured by the metallic key, so a repeat study was not necessary.

Radiograph D

9. A cat.

10. The cat swallowed its owner’s pierced earring! The missing jewelry is visualized in the cat’s stomach. Note that because of the small part-thickness of this animal, technical adjustments in milliamperes and kilovolts (peak) are necessary to produce a radiograph that demonstrates bony anatomy as well as the soft tissue anatomy. The heart, liver, stomach, and intestines are easily identifiable.

Chapter 2

Radiograph A

1. Anteroposterior projection of the right femur.

2. The bone density of the distal femoral shaft is abnormally uneven. There is loss of a distinct cortical shell and no interface between the cortex and the medullary canal. The external architecture of the distal shaft is also uneven and deformed. These gross changes in mineralization are indications of a pathological state.

3. No. The upper half of the femoral shaft and the pelvis do not show the bony changes as listed in answer 2. However, the neck of the femur does exhibit osteopenia and thinned cortical margins. This could be related to disuse atrophy.

4. No. The evidence of previous surgical intervention is revealed by the regularly spaced radiolucent lines representing the removal of sideplate fixation screws.

5. No. The hip joint ...