During a mass casualty incident in a remote area, the NOMAD PRO 2 is
deployed. Which of the following best describes the primary radiation
protection principle that must be applied when operating this device near other
responders?
A. Time, distance, and shielding, with distance being the most effective
due to the inverse square law.
B. Time, distance, and shielding, with time being the most effective
because exposure is cumulative.
C. Use of lead aprons alone is sufficient as the device is self-shielded.
D. Increasing distance is ineffective because the NOMAD PRO 2 emits a
focused beam with minimal scatter.
Correct Answer: A - Time, distance, and shielding, with distance
being the most effective due to the inverse square law.
RATIONALE
The inverse square law states that radiation intensity is inversely
proportional to the square of the distance from the source. Doubling
distance reduces exposure to one-quarter, making distance the most
effective single protective measure. Time and shielding are also
important but less impactful than distance for a portable device.
Question 2
A patient with a suspected cervical spine injury is being evaluated in the field
using the NOMAD PRO 2. The provider obtains a lateral cervical spine image.
Which radiographic finding would most strongly indicate the need for
immediate immobilization and transport to a trauma center?
A. Loss of cervical lordosis
B. Prevertebral soft tissue swelling exceeding 5 mm at C3
C. Mild degenerative changes at C5-C6
D. Osteophyte formation at C4
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,Correct Answer: B - Prevertebral soft tissue swelling exceeding 5
mm at C3
RATIONALE
Prevertebral soft tissue swelling >5 mm at C3 is a sensitive indicator
of underlying cervical spine injury and hemorrhage. Loss of lordosis
can be positional, while degenerative changes and osteophytes are
chronic and not acute injury markers.
Question 3
Which of the following technical parameters most directly affects the contrast
resolution of images obtained with the NOMAD PRO 2, and how should it be
adjusted for a patient with a large body habitus?
A. mAs; increase to improve contrast
B. kVp; increase to penetrate thicker tissue and reduce scatter
C. kVp; decrease to increase contrast
D. Focal spot size; decrease to improve detail
Correct Answer: B - kVp; increase to penetrate thicker tissue and
reduce scatter
RATIONALE
kVp controls the penetrating power of the X-ray beam and affects
contrast. For a large patient, increasing kVp is necessary to penetrate
tissue, but it reduces contrast; however, it is the primary adjustment.
mAs affects density, not contrast primarily. Decreasing kVp would
underpenetrate.
Question 4
A patient presents with a suspected pneumothorax after blunt chest trauma.
The NOMAD PRO 2 is used to obtain an upright PA chest image. Which
radiographic sign is most specific for a tension pneumothorax that requires
immediate needle decompression?
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, A. Deep sulcus sign
B. Mediastinal shift to the contralateral side
C. Visceral pleural line
D. Subcutaneous emphysema
Correct Answer: B - Mediastinal shift to the contralateral side
RATIONALE
Mediastinal shift away from the affected side indicates tension
physiology and is a specific sign of tension pneumothorax. The
visceral pleural line and deep sulcus sign indicate simple
pneumothorax. Subcutaneous emphysema is non-specific.
Question 5
During operation of the NOMAD PRO 2, the device displays a 'Tube Overheat'
error. Which of the following actions is most appropriate to safely resume
imaging?
A. Immediately power cycle the device and continue imaging.
B. Allow the device to cool for the recommended time, then resume.
C. Increase the kVp to reduce exposure time and heat load.
D. Bypass the error by switching to manual mode.
Correct Answer: B - Allow the device to cool for the
recommended time, then resume.
RATIONALE
Tube overheat indicates excessive heat accumulation in the X-ray
tube. The device must cool to prevent damage. Power cycling or
bypassing may cause permanent damage. Increasing kVp would
increase heat production.
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