ANSWER KEY Diagnostic Focus in Imaging Studies - Respiratory Therapist Reviewer

Chest X-ray Interpretation
 
1. Which of the following appears as a white (radiopaque) area on a chest X-ray?
A. Fluid or consolidation
B. Air in the lungs
C. Gas in the stomach
D. Normal lung tissue
Answer: A.
Explanation: Fluid, consolidation (e.g., pneumonia), or masses appear white (radiopaque) on X-rays, while air appears black (radiolucent).
 
2. A chest X-ray showing a “bat-wing” pattern is characteristic of which condition?
A. Pneumonia
B. Pulmonary edema
C. Pneumothorax
D. Tuberculosis
Answer: B.
Explanation: The bat-wing appearance is typical of pulmonary edema, often due to congestive heart failure.
 
3. Which condition is indicated by a “blunting of the costophrenic angle” on a chest X-ray?
A. Pleural effusion
B. Pneumothorax
C. Pulmonary embolism
D. Emphysema
Answer: A.
Explanation: Pleural effusion causes fluid accumulation in the pleural space, leading to costophrenic angle blunting.
 
4. A collapsed lung (pneumothorax) on a chest X-ray appears as:
A. An area of increased radiopacity with air-fluid levels
B. A white-out of the entire lung field
C. A dark (radiolucent) area without lung markings
D. A consolidation in the lower lobes
Answer: C.
Explanation: Pneumothorax is seen as a radiolucent (dark) area with no lung markings due to air in the pleural space.
 
5. A patient with tuberculosis (TB) is most likely to show what pattern on a chest X-ray?
A. Diffuse ground-glass opacities
B. Blunting of the costophrenic angles
C. Honeycombing in the lungs
D. Cavitary lesions in the upper lobes
Answer: D.
Explanation: TB typically causes cavitary lesions (air-filled spaces) in the upper lobes of the lungs.
 
6. Which view is most commonly used in a routine chest X-ray?
A. Anteroposterior (AP)
B. Posteroanterior (PA)
C. Lateral
D. Oblique
Answer: B.
Explanation: The PA view is the standard for chest X-rays because it provides better lung detail and minimizes cardiac magnification.
 
7. A "ground-glass opacity" on a chest X-ray is commonly associated with:
A. Interstitial lung disease
B. Pneumonia
C. Pulmonary embolism
D. All of the above
Answer: D.
Explanation: Ground-glass opacity is a nonspecific finding that may be seen in pneumonia, interstitial lung disease, and pulmonary embolism.
 
CT Scan Interpretation
 
8. What is the primary imaging modality for detecting pulmonary embolism?
A. CT Pulmonary Angiography (CTPA)
B. Chest X-ray
C. MRI
D. Ultrasound
Answer: A.
Explanation: CTPA is the gold standard for detecting pulmonary embolism (PE), showing emboli in the pulmonary arteries.
 
9. Which lung condition is best diagnosed using high-resolution CT (HRCT)?
A. Pneumonia
B. Interstitial lung disease
C. Pleural effusion
D. Asthma
Answer: B.
Explanation: HRCT provides detailed images of the lung parenchyma, making it ideal for interstitial lung disease evaluation.
 
10. Which CT scan finding is characteristic of emphysema?
A. Honeycombing
B. Ground-glass opacities
C. Hyperinflated lungs with bullae
D. Pleural thickening
Answer: C.
Explanation: Emphysema appears as hyperinflated lungs with bullae (air-filled spaces) due to alveolar destruction.
 
11. A “tree-in-bud” pattern on a CT scan suggests:
A. Bronchiolitis or tuberculosis
B. Pulmonary embolism
C. Pulmonary fibrosis
D. Pneumothorax
Answer: A.
Explanation: The tree-in-bud pattern suggests bronchiolar inflammation, often seen in bronchiolitis or tuberculosis.
 
12. Which of the following is the hallmark CT finding in pulmonary fibrosis?
A. Tree-in-bud pattern
B. Honeycombing
C. Ground-glass opacities
D. Pleural effusion
Answer: B.
Explanation: Honeycombing on CT is characteristic of pulmonary fibrosis, showing cystic airspaces due to lung scarring.
 
13. Which of the following findings on a CT scan suggests bronchiectasis?
A. Dilated bronchi with thickened walls
B. Ground-glass opacities
C. Mediastinal shift
D. Bullous formations
Answer: A.
Explanation: Bronchiectasis is characterized by permanently dilated bronchi with thickened walls, often from chronic infections.
 
14. Which condition is associated with a "crazy paving" pattern on high-resolution CT (HRCT)?
A. Interstitial lung disease
B. Pulmonary embolism
C. Pulmonary alveolar proteinosis
D. Tuberculosis
Answer: C.
Explanation: Crazy paving (a mix of ground-glass opacities and septal thickening) is typical of pulmonary alveolar proteinosis (PAP).
 
MRI and Ultrasound in Pulmonary Diagnosis
 
15. Which condition is best evaluated using lung ultrasound?
A. Pleural effusion
B. Pulmonary embolism
C. Tuberculosis
D. Interstitial lung disease
Answer: A.
Explanation: Ultrasound is best for detecting pleural effusion, as it shows real-time fluid movement.
 
16. Why is MRI not commonly used for lung imaging?
A. MRI is too expensive
B. Lungs contain air, which limits MRI resolution
C. MRI uses ionizing radiation
D. MRI cannot differentiate soft tissues
Answer: B.
Explanation: MRI is not ideal for lung imaging because air does not produce strong MRI signals, making CT scans superior.
 
17. Which imaging modality is preferred for detecting mediastinal tumors?
A. Chest X-ray
B. CT scan
C. MRI
D. Ultrasound
Answer: C.
Explanation: MRI is preferred for mediastinal tumors because it provides superior soft-tissue contrast.
 
18. What is the primary advantage of ultrasound over CT for pleural effusion detection?
A. Higher sensitivity
B. Faster imaging
C. No radiation exposure
D. All of the above
Answer: D.
Explanation: Ultrasound is fast, radiation-free, and highly sensitive in detecting pleural effusions.
 
19. Which lung pathology is best evaluated using MRI rather than CT?
A. Lung nodules
B. Pulmonary embolism
C. Mediastinal tumors
D. Pneumothorax
Answer: C.
Explanation: MRI is preferred for mediastinal tumors because it provides superior soft tissue contrast compared to CT.
 
20. Why is MRI not commonly used for routine lung imaging?
A. It is too expensive
B. MRI has lower resolution for lung tissue due to air interference
C. MRI exposes the patient to radiation
D. MRI does not differentiate bone from soft tissue
Answer: B.
Explanation: MRI has poor resolution in the lungs because air interferes with signal detection, making CT scans superior for lung imaging.
 
21. Which of the following is best diagnosed using thoracic ultrasound?
A. Pulmonary embolism
B. Pleural effusion
C. Lung cancer
D. Bronchiectasis
Answer: B.
Explanation: Thoracic ultrasound is ideal for detecting pleural effusion and can be used for guided thoracentesis.
 
22. Which ultrasound sign is indicative of a pneumothorax?
A. B-lines
B. Lung sliding
C. Barcode sign (Stratosphere sign)
D. Pleural thickening
Answer: C.
Explanation: The barcode sign (stratosphere sign) occurs when there is no lung sliding, indicating a pneumothorax.
 
23. What is the advantage of ultrasound over X-ray for diagnosing pleural effusion?
A. Can detect small amounts of fluid
B. Does not use radiation
C. Can be done at the bedside
D. All of the above
Answer: D.
Explanation: Ultrasound is superior for pleural effusion because it detects small fluid amounts, is radiation-free, and portable.
 
Advanced Imaging and Clinical Cases
 
24. Which of the following best describes the "Westermark sign" on a chest X-ray?
A. Hyperinflation of one lung
B. Bilateral pleural effusions
C. Ground-glass opacities
D. A wedge-shaped area of lung oligemia
Answer: D.
Explanation: The Westermark sign suggests pulmonary embolism and appears as a wedge-shaped area of decreased lung markings (oligemia).
 
25. Which imaging modality is most sensitive for detecting lung cancer?
A. Chest X-ray
B. CT scan
C. MRI
D. Ultrasound
Answer: B.
Explanation: CT scans are more sensitive than X-rays for detecting lung cancer, identifying small nodules that may be missed on X-ray.
 
26. Which of the following is a common radiographic sign of pneumonia on a chest X-ray?
A. Hyperinflation
B. Patchy or lobar consolidation
C. Air-fluid levels
D. Pleural effusion
Answer: B.
Explanation: Pneumonia appears as patchy or lobar consolidation due to alveolar fluid accumulation.
 
27. Which condition would show a "Kerley B line" on a chest X-ray?
A. Pulmonary embolism
B. Pulmonary fibrosis
C. Pneumothorax
D. Congestive heart failure
Answer: D.
Explanation: Kerley B lines are short, horizontal lines at the lung periphery, indicating pulmonary edema from congestive heart failure.
 
28. A 65-year-old smoker presents with hemoptysis and weight loss. Which imaging modality is best for initial assessment?
A. Chest X-ray
B. Ultrasound
C. MRI
D. CT scan
Answer: D.
Explanation: CT scan is preferred for lung cancer screening, especially in high-risk patients like smokers.
 
29. Which finding suggests an acute pulmonary embolism on CT?
A. Hyperinflated lungs
B. Westermark sign
C. Blunted costophrenic angle
D. Cavitary lesion
Answer: B.
Explanation: The Westermark sign (a wedge-shaped area of hypoperfusion) is a classic pulmonary embolism indicator.
 
30. Which imaging modality is safest for pregnant patients needing lung evaluation?
A. CT scan
B. MRI
C. Ultrasound
D. X-ray
Answer: C.
Explanation: Ultrasound is the safest as it does not use radiation. MRI can be used if needed.