,CHAPTER 1: INTRODUCTION TO RADIOLOGIC SCIENCE
1. Which of the following best describes the primary purpose of diagnostic
radiography?
A. To treat diseases using ionizing radiation
B. To produce images of internal structures for diagnosis
C. To monitor patient vital signs
D. To sterilize medical equipment
Answer: B
Rationale: Diagnostic radiography’s main purpose is to produce images of internal
body structures, allowing physicians to detect and diagnose abnormalities. Options
A, C, and D are unrelated to diagnostic imaging.
2. What is the primary source of ionizing radiation in medical imaging?
A. MRI scanner
B. X-ray tube
C. Ultrasound transducer
D. PET scanner
Answer: B
Rationale: The X-ray tube generates ionizing radiation used in diagnostic
radiography. MRI and ultrasound use non-ionizing energy, while PET uses
radioactive tracers rather than producing radiation in a tube.
3. How does the ALARA principle guide radiologic practice?
A. Maximizing image quality regardless of dose
B. Minimizing radiation exposure while achieving diagnostic quality
C. Limiting patient interaction to reduce infection
D. Increasing exposure time for better penetration
Answer: B
Rationale: ALARA (“As Low As Reasonably Achievable”) ensures patient and
staff receive the minimum radiation dose necessary for diagnostic-quality images.
,4. A radiologic technologist is preparing to image a patient with a suspected
fracture. Which safety measure is most important?
A. Using the fastest imaging speed
B. Ensuring proper patient shielding and positioning
C. Increasing exposure to reduce repeat images
D. Allowing the patient to move during imaging
Answer: B
Rationale: Proper shielding and positioning minimize unnecessary exposure and
protect radiosensitive tissues. Options A, C, and D can increase radiation risk or
degrade image quality.
5. Scenario: A 45-year-old patient expresses concern about radiation exposure.
How should the technologist respond?
A. Ignore their concerns; radiation is safe
B. Explain that dose is minimized and benefits outweigh risks
C. Refuse to perform the exam
D. Increase exposure to ensure better images
Answer: B
Rationale: Patients should be informed about the low dose and the diagnostic
benefits, reducing anxiety and promoting informed consent.
6. Which professional organization establishes standards for radiologic
technologists?
A. WHO
B. ASRT
C. FDA
D. CDC
Answer: B
Rationale: The American Society of Radiologic Technologists (ASRT) sets
educational and professional standards. FDA regulates equipment, CDC focuses on
infection control, WHO on global health.
, 7. Which imaging modality does not use ionizing radiation?
A. CT scan
B. MRI
C. X-ray
D. Fluoroscopy
Answer: B
Rationale: MRI uses magnetic fields and radio waves, which are non-ionizing.
CT, X-ray, and fluoroscopy all use ionizing radiation.
8. What is the most radiosensitive tissue in the human body?
A. Muscle
B. Skin
C. Bone marrow
D. Cartilage
Answer: C
Rationale: Bone marrow contains rapidly dividing cells, making it highly sensitive
to ionizing radiation. Muscle, skin, and cartilage are less sensitive.
9. Which factor primarily affects the quality of an X-ray image?
A. Patient diet
B. Tube voltage and current
C. Room temperature
D. Technologist height
Answer: B
Rationale: Tube voltage (kVp) and current (mA) control X-ray energy and photon
quantity, directly affecting image quality.
10. How often should radiologic equipment be tested for quality assurance?
A. Daily
B. Monthly
C. Annually
D. Only when malfunction occurs
1. Which of the following best describes the primary purpose of diagnostic
radiography?
A. To treat diseases using ionizing radiation
B. To produce images of internal structures for diagnosis
C. To monitor patient vital signs
D. To sterilize medical equipment
Answer: B
Rationale: Diagnostic radiography’s main purpose is to produce images of internal
body structures, allowing physicians to detect and diagnose abnormalities. Options
A, C, and D are unrelated to diagnostic imaging.
2. What is the primary source of ionizing radiation in medical imaging?
A. MRI scanner
B. X-ray tube
C. Ultrasound transducer
D. PET scanner
Answer: B
Rationale: The X-ray tube generates ionizing radiation used in diagnostic
radiography. MRI and ultrasound use non-ionizing energy, while PET uses
radioactive tracers rather than producing radiation in a tube.
3. How does the ALARA principle guide radiologic practice?
A. Maximizing image quality regardless of dose
B. Minimizing radiation exposure while achieving diagnostic quality
C. Limiting patient interaction to reduce infection
D. Increasing exposure time for better penetration
Answer: B
Rationale: ALARA (“As Low As Reasonably Achievable”) ensures patient and
staff receive the minimum radiation dose necessary for diagnostic-quality images.
,4. A radiologic technologist is preparing to image a patient with a suspected
fracture. Which safety measure is most important?
A. Using the fastest imaging speed
B. Ensuring proper patient shielding and positioning
C. Increasing exposure to reduce repeat images
D. Allowing the patient to move during imaging
Answer: B
Rationale: Proper shielding and positioning minimize unnecessary exposure and
protect radiosensitive tissues. Options A, C, and D can increase radiation risk or
degrade image quality.
5. Scenario: A 45-year-old patient expresses concern about radiation exposure.
How should the technologist respond?
A. Ignore their concerns; radiation is safe
B. Explain that dose is minimized and benefits outweigh risks
C. Refuse to perform the exam
D. Increase exposure to ensure better images
Answer: B
Rationale: Patients should be informed about the low dose and the diagnostic
benefits, reducing anxiety and promoting informed consent.
6. Which professional organization establishes standards for radiologic
technologists?
A. WHO
B. ASRT
C. FDA
D. CDC
Answer: B
Rationale: The American Society of Radiologic Technologists (ASRT) sets
educational and professional standards. FDA regulates equipment, CDC focuses on
infection control, WHO on global health.
, 7. Which imaging modality does not use ionizing radiation?
A. CT scan
B. MRI
C. X-ray
D. Fluoroscopy
Answer: B
Rationale: MRI uses magnetic fields and radio waves, which are non-ionizing.
CT, X-ray, and fluoroscopy all use ionizing radiation.
8. What is the most radiosensitive tissue in the human body?
A. Muscle
B. Skin
C. Bone marrow
D. Cartilage
Answer: C
Rationale: Bone marrow contains rapidly dividing cells, making it highly sensitive
to ionizing radiation. Muscle, skin, and cartilage are less sensitive.
9. Which factor primarily affects the quality of an X-ray image?
A. Patient diet
B. Tube voltage and current
C. Room temperature
D. Technologist height
Answer: B
Rationale: Tube voltage (kVp) and current (mA) control X-ray energy and photon
quantity, directly affecting image quality.
10. How often should radiologic equipment be tested for quality assurance?
A. Daily
B. Monthly
C. Annually
D. Only when malfunction occurs
