Radiography Exam Radiology Tech 5 — Questions and Answers
Question 1: Which anatomical landmark is used to position for a posteroanterior (PA) chest radiograph?
- Iliac crest
- Jugular notch
- Vertebra prominens (C7) (Correct answer)
- Acromion process
Correct answer: Vertebra prominens (C7)
The vertebra prominens (C7) is palpated to confirm proper centering for PA chest projections, with the IR centered at T7.
Question 2: What is 'beam restriction' and why is it important in radiographic practice?
- Reducing kVp to limit photon energy; prevents overexposure
- Limiting the X-ray field size; reduces patient dose and scatter (Correct answer)
- Filtering low-energy photons; increases image contrast only
- Adjusting mAs; controls image density only
Correct answer: Limiting the X-ray field size; reduces patient dose and scatter
Beam restriction (collimation) limits the field of radiation to the area being imaged, reducing patient dose and scatter radiation that degrades image quality.
Question 3: Which X-ray interaction results in the complete absorption of the photon by an inner-shell electron?
- Compton scatter
- Coherent scatter
- Photoelectric effect (Correct answer)
- Pair production
Correct answer: Photoelectric effect
In the photoelectric effect, an X-ray photon is completely absorbed by an inner-shell electron, which is then ejected from the atom.
Question 4: What is the recommended source-to-image distance (SID) for routine chest radiography?
- 40 inches (102 cm)
- 48 inches (122 cm)
- 72 inches (183 cm) (Correct answer)
- 36 inches (91 cm)
Correct answer: 72 inches (183 cm)
A 72-inch (183 cm) SID is standard for PA chest radiography to minimize magnification of the heart and improve image sharpness.
Question 5: Which of the following describes 'radiographic density' (optical density) on a conventional film?
- The degree of sharpness at the edge of structures
- The overall blackness or darkness of the radiographic image (Correct answer)
- The difference in blackness between adjacent structures
- The size distortion of anatomical structures
Correct answer: The overall blackness or darkness of the radiographic image
Radiographic density (optical density) refers to the degree of overall blackening of the film, primarily controlled by mAs.
Question 6: What does 'spatial resolution' measure in a radiographic image?
- The ability to distinguish between tissues of similar density
- The ability to image small, high-contrast details and edges (Correct answer)
- The overall brightness of the image
- The degree of magnification present
Correct answer: The ability to image small, high-contrast details and edges
Spatial resolution refers to the system's ability to resolve fine structural detail and sharp edges, measured in line pairs per millimeter (lp/mm).
Question 7: Which radiation protection device should always be worn at collar level outside the lead apron during fluoroscopy?
- Ring dosimeter
- Collar (thyroid) dosimeter (Correct answer)
- Extremity badge
- Whole-body dosimeter at waist
Correct answer: Collar (thyroid) dosimeter
A collar-level dosimeter worn outside the lead apron during fluoroscopy monitors the highest dose area (head and neck) and is used to estimate effective dose.
Radiography Exam Radiology Tech 5
Which anatomical landmark is used to position for a posteroanterior (PA) chest radiograph?