ESTUDYR
PHA 570 - Exam 1 XR
1. Radiographs account for approximately what percentage of all diagnostic imaging
examinations?
A. 10–20%
B. 30–40%
C. 70–80%
D. 90–95%
Rationale: Conventional radiographs remain the most frequently used imaging modality due to
availability, speed, and cost-effectiveness, accounting for roughly 70–80% of all imaging
studies.
2. Which clinical situation is the MOST appropriate indication for obtaining a radiograph?
A. Mild muscle soreness after exercise
B. Suspected fracture with inability to bear weight
C. Routine screening of asymptomatic joints
D. Chronic fatigue without focal symptoms
Rationale: Radiographs are indicated when structural pathology is suspected, such as fractures,
deformity, unexplained pain, or inability to use an extremity.
3. How does doubling the distance from a radiation source affect radiation exposure?
A. Exposure doubles
B. Exposure is unchanged
C. Exposure is halved
D. Exposure is reduced to one-quarter
Rationale: This reflects the inverse square law: doubling the distance from a radiation source
reduces exposure to one-quarter.
, ESTUDYR
4. As X-ray beams diverge from the source, what effect occurs on anatomical structures
closer to the source?
A. Decreased magnification
B. Distortion is eliminated
C. Magnification is increased
D. Density appears reduced
Rationale: Structures closer to the beam source are magnified more than those closer to the
detector.
5. A near beam source results in which imaging effect?
A. Reduced distortion
B. Improved spatial resolution
C. Exaggerated size of structures
D. Increased image noise
Rationale: Shorter source-to-image distance increases magnification and distortion.
6. Why does an AP chest radiograph exaggerate heart size?
A. Increased lung density
B. Heart is closer to the X-ray source
C. Detector sensitivity is reduced
D. Scattered radiation increases
Rationale: In AP views, the heart lies closer to the source, causing magnification.
7. What is the primary advantage of a PA chest projection?
A. Reduced radiation dose
B. Improved lung inflation
C. More accurate heart size representation
D. Faster image acquisition
Rationale: The PA view places the heart closer to the detector, minimizing magnification.
PHA 570 - Exam 1 XR
1. Radiographs account for approximately what percentage of all diagnostic imaging
examinations?
A. 10–20%
B. 30–40%
C. 70–80%
D. 90–95%
Rationale: Conventional radiographs remain the most frequently used imaging modality due to
availability, speed, and cost-effectiveness, accounting for roughly 70–80% of all imaging
studies.
2. Which clinical situation is the MOST appropriate indication for obtaining a radiograph?
A. Mild muscle soreness after exercise
B. Suspected fracture with inability to bear weight
C. Routine screening of asymptomatic joints
D. Chronic fatigue without focal symptoms
Rationale: Radiographs are indicated when structural pathology is suspected, such as fractures,
deformity, unexplained pain, or inability to use an extremity.
3. How does doubling the distance from a radiation source affect radiation exposure?
A. Exposure doubles
B. Exposure is unchanged
C. Exposure is halved
D. Exposure is reduced to one-quarter
Rationale: This reflects the inverse square law: doubling the distance from a radiation source
reduces exposure to one-quarter.
, ESTUDYR
4. As X-ray beams diverge from the source, what effect occurs on anatomical structures
closer to the source?
A. Decreased magnification
B. Distortion is eliminated
C. Magnification is increased
D. Density appears reduced
Rationale: Structures closer to the beam source are magnified more than those closer to the
detector.
5. A near beam source results in which imaging effect?
A. Reduced distortion
B. Improved spatial resolution
C. Exaggerated size of structures
D. Increased image noise
Rationale: Shorter source-to-image distance increases magnification and distortion.
6. Why does an AP chest radiograph exaggerate heart size?
A. Increased lung density
B. Heart is closer to the X-ray source
C. Detector sensitivity is reduced
D. Scattered radiation increases
Rationale: In AP views, the heart lies closer to the source, causing magnification.
7. What is the primary advantage of a PA chest projection?
A. Reduced radiation dose
B. Improved lung inflation
C. More accurate heart size representation
D. Faster image acquisition
Rationale: The PA view places the heart closer to the detector, minimizing magnification.
