L1 (Basic)
L1 Question 1:
What is the primary imaging feature of random micronodules?
a) Centrilobular distribution
b) Uniform size and random distribution
c) Subpleural consolidation
d) Air bronchograms
Answer:
b) Uniform size and random distribution
Comment:
Random micronodules are small, round opacities (<3 mm) that are evenly distributed throughout the lungs without a preference for specific structures, unlike centrilobular nodules.
“Random micronodules appear as uniformly distributed small nodules without an anatomical preference, often due to hematogenous spread.” Radiopaedia
Incorrect Answers:
a) “Centrilobular nodules are confined to the center of secondary pulmonary lobules, often linked to airway diseases rather than random hematogenous processes.” Radiopaedia
c) “Subpleural consolidations are not characteristic of random micronodules but rather organizing pneumonia or fibrosis.” Radiographics
d) “Air bronchograms are a sign of alveolar consolidation, not random micronodules.” Radiopaedia
L1 Question 2:
Which of the following conditions commonly presents with random micronodules?
a) Miliary tuberculosis
b) Sarcoidosis
c) Silicosis
d) Centrilobular emphysema
Answer:
a) Miliary tuberculosis
Comment:
Miliary tuberculosis is a classic example of random micronodules due to hematogenous dissemination of Mycobacterium tuberculosis.
“Miliary TB is a prime example of random micronodular lung disease, reflecting widespread hematogenous spread.” Radiopaedia
Incorrect Answers:
b) “Sarcoidosis typically presents with perilymphatic nodules rather than a random distribution.” Radiopaedia
c) “Silicosis features upper lobe predominant nodules, not random hematogenous spread.” Radiographics
d) “Centrilobular emphysema does not manifest as micronodules but as areas of low attenuation.” Radiopaedia
L1 Question 3:
Which is the primary modality for detecting random micronodules?
a) Chest X-ray
b) Chest CT
c) MRI
d) PET-CT
Answer:
b) Chest CT
Comment:
High-resolution chest CT is the most sensitive modality for detecting micronodules due to its superior spatial resolution.
“HRCT is the imaging modality of choice for the assessment of small pulmonary nodules, including random micronodules.” Radiographics
Incorrect Answers:
a) “Chest X-ray lacks sensitivity for detecting micronodules.” Radiopaedia
c) “MRI is not standard for evaluating lung parenchymal nodules.” Radiopaedia
d) “PET-CT assesses metabolic activity but lacks the spatial detail to detect small micronodules.” Radiopaedia
L1 Question 4:
Which of the following diseases is least likely to present with random micronodules?
a) Miliary TB
b) Metastatic thyroid cancer
c) Pneumocystis jiroveci pneumonia
d) Disseminated histoplasmosis
Answer:
c) Pneumocystis jiroveci pneumonia
Comment:
Pneumocystis jiroveci pneumonia typically presents with ground-glass opacities rather than random micronodules.
“PJP commonly presents as diffuse ground-glass opacities rather than micronodules.” Radiopaedia
L1 Question 5:
What is the typical size of a random micronodule?
a) <3 mm
b) 3-5 mm
c) 5-10 mm
d) >10 mm
Answer:
a) <3 mm
Comment:
Micronodules are defined as nodules smaller than 3 mm.
“Micronodules measure less than 3 mm and are typically identified on HRCT.” Fleischner Society Guidelines
L2 (Advanced)
L2 Question 6:
A patient presents with multiple random micronodules, night sweats, and weight loss. Which test is most appropriate for further evaluation?
a) Tuberculin skin test (TST)
b) D-dimer
c) Echocardiogram
d) V/Q scan
Answer:
a) Tuberculin skin test (TST)
Comment:
The presentation suggests miliary tuberculosis, and a TST is an appropriate initial screening tool.
“Miliary TB often presents with systemic symptoms and random micronodules, warranting further investigation with a TST or IGRA.” Radiopaedia
L2 Question 7:
Which statement is true regarding random micronodules on imaging?
a) They are often associated with hematogenous spread.
b) They spare the pleural surfaces.
c) They are commonly caused by inhalational exposure.
d) They are larger than 3 mm.
Answer:
a) They are often associated with hematogenous spread.
L2 Question 8:
Which histologic feature correlates with random micronodules in miliary TB?
a) Caseating granulomas
b) Fibrotic changes
c) Perilymphatic granulomas
d) Alveolar consolidation
Answer:
a) Caseating granulomas
L2 Question 9:
A patient with metastatic melanoma presents with random micronodules. What is the primary mechanism?
a) Airway dissemination
b) Lymphatic spread
c) Hematogenous spread
d) Direct pleural invasion
Answer:
c) Hematogenous spread
L2 Question 10: A 50-year-old patient with a history of treated metastatic melanoma presents with persistent, randomly distributed micronodules identified on a follow-up chest CT. What is the most appropriate next step?
a) PET-CT scan to assess metabolic activity
b) High-resolution CT (HRCT) for better characterization
c) Empiric anti-tuberculous treatment
d) Start antifungal therapy for presumed histoplasmosis
e) Surgical biopsy for definitive histological diagnosis
Answer:
a) PET-CT scan to assess metabolic activity
Comment:
In a patient with a history of metastatic disease and persistent random micronodules, a PET-CT scan is an appropriate next step to assess metabolic activity and determine if the nodules are metabolically active, which would raise concern for metastatic recurrence.
“PET-CT is useful for evaluating metabolic activity and can help differentiate benign from malignant nodules, especially in a patient with a known history of malignancy.” Radiopaedia
Incorrect Answers:
b) “HRCT is valuable for initial characterization but may not provide functional information on metabolic activity, which PET-CT can assess.” Radiographics
c) “Empiric anti-tuberculous therapy without confirmatory evidence is not standard practice.” Radiopaedia
d) “Fungal infections like histoplasmosis should be confirmed with serologic testing or histopathology before treatment initiation.” Radiographics
e) “Surgical biopsy is invasive and typically reserved for cases where imaging and non-invasive tests are inconclusive.” Radiopaedia