L1 Question 1:
What size is used to define a micronodule on chest CT?
a) <1 mm
b) <3 mm
c) <5 mm
d) 3-10 mm
e) >10 mm
Answer:
b) <3 mm
Comment:
Micronodules are defined as small, round opacities measuring less than 3 mm.
“Micronodules are round pulmonary opacities measuring <3 mm, often related to granulomatous, infectious, or neoplastic processes.” Radiopaedia
Incorrect Answers:
- a) “Nodules smaller than 1 mm are generally undetectable on standard chest CT.” Radiopaedia
- c) “Nodules measuring 3-5 mm are categorized as small nodules, not micronodules.” Fleischner Society Guidelines
- d) “Nodules 3-10 mm are not considered micronodules but rather small pulmonary nodules.” Radiopaedia
L1 Question 2:
Which disease most commonly presents with centrilobular micronodules?
a) Sarcoidosis
b) Hypersensitivity Pneumonitis
c) Tuberculosis
d) Lymphangitic Carcinomatosis
e) Metastatic Disease
Answer:
b) Hypersensitivity Pneumonitis
Comment:
Hypersensitivity pneumonitis often presents with centrilobular micronodules, sparing the pleural surfaces.
“Centrilobular micronodules sparing the pleura are typical in hypersensitivity pneumonitis and reflect small airway inflammation.” Radiopaedia
Incorrect Answers:
- a) “Sarcoidosis presents with perilymphatic nodules, not centrilobular.” Radiopaedia
- c) “Tuberculosis often presents with random or perilymphatic micronodules.” Radiopaedia
L1 Question 3:
Which distribution is most commonly associated with sarcoidosis?
a) Random
b) Centrilobular
c) Perilymphatic
d) Ground-glass
e) Tree-in-bud
Answer:
c) Perilymphatic
Comment:
Perilymphatic nodules along the bronchovascular bundles and fissures are highly characteristic of sarcoidosis.
“Perilymphatic nodules involving the bronchovascular bundles and fissures are a hallmark of sarcoidosis.” Radiopaedia
Incorrect Answers:
- a) “Random distribution is more consistent with hematogenous spread, such as miliary TB.” Radiographics
L1 Question 4:
Which of the following infections is most likely to present with random micronodules?
a) Tuberculosis
b) Viral Pneumonia
c) Miliary Tuberculosis
d) Sarcoidosis
e) Pulmonary Edema
Answer:
c) Miliary Tuberculosis
Comment:
Miliary TB results in random micronodules due to hematogenous spread of infection.
“Miliary tuberculosis typically presents with randomly distributed micronodules due to hematogenous spread.” Radiopaedia
L1 Question 5:
Which imaging modality is most sensitive for detecting micronodules?
a) Chest X-ray
b) High-Resolution CT (HRCT)
c) PET-CT
d) MRI
e) Ultrasound
Answer:
b) High-Resolution CT (HRCT)
Comment:
HRCT is the preferred imaging modality for micronodules due to its superior spatial resolution compared to standard chest X-rays.
“HRCT provides high spatial resolution, making it the gold standard for detecting micronodules.” Fleischner Society Guidelines
L2 (Advanced Clinical Integration)
L2 Question 6:
A 55-year-old male presents with micronodules and mediastinal lymphadenopathy. The nodules are distributed along the fissures and bronchovascular bundles. Which disease is most likely?
a) Sarcoidosis
b) Hypersensitivity Pneumonitis
c) Metastatic Disease
d) Lymphangitic Carcinomatosis
e) Tuberculosis
Answer:
a) Sarcoidosis
Comment:
Perilymphatic micronodules with mediastinal lymphadenopathy are characteristic of sarcoidosis.
“Sarcoidosis frequently presents with perilymphatic nodules and mediastinal lymphadenopathy.” Radiopaedia
L2 Question 7:
A 65-year-old smoker presents with random micronodules and a positive PET-CT scan. Which condition is most likely?
a) Sarcoidosis
b) Lymphangitic Carcinomatosis
c) Metastatic Disease
d) Hypersensitivity Pneumonitis
e) Silicosis
Answer:
c) Metastatic Disease
Comment:
Random micronodules with PET avidity often suggest metastatic disease.
“Random nodules with metabolic activity raise concern for hematogenous metastases.” Radiopaedia
L2 Question 8:
A 40-year-old female presents with centrilobular micronodules sparing the pleura and ground-glass opacities. What is the most likely diagnosis?
a) Hypersensitivity Pneumonitis
b) Sarcoidosis
c) Lymphangitic Carcinomatosis
d) Pulmonary Edema
e) Tuberculosis
Answer:
a) Hypersensitivity Pneumonitis
Comment:
Centrilobular micronodules with ground-glass opacities favor hypersensitivity pneumonitis.
“Centrilobular nodules with ground-glass opacities are a hallmark of hypersensitivity pneumonitis.” Radiopaedia
L2 Question 9:
A patient with a history of treated TB presents with perilymphatic micronodules and calcified hilar lymph nodes. What does this pattern most likely represent?
a) Active tuberculosis
b) Healed granulomatous disease
c) Sarcoidosis
d) Miliary tuberculosis
e) Metastatic disease
Answer:
b) Healed granulomatous disease
Comment:
Calcified hilar lymph nodes and stable perilymphatic nodules suggest prior granulomatous infection rather than active disease.
“Calcified lymph nodes with stable nodules suggest healed granulomatous disease.” Radiopaedia
L2 Question 10:
A 45-year-old patient with a history of lymphangitic carcinomatosis presents with micronodules along the fissures and interlobular septal thickening. Which imaging pattern best correlates with this diagnosis?
a) Centrilobular distribution
b) Perilymphatic distribution
c) Tree-in-bud pattern
d) Random distribution
e) Subpleural nodules
Answer:
b) Perilymphatic distribution
Comment:
Lymphangitic carcinomatosis typically presents with perilymphatic nodules along the fissures and bronchovascular bundles, accompanied by interlobular septal thickening, indicating lymphatic involvement.
“Lymphangitic carcinomatosis commonly involves the perilymphatic distribution of nodules along the bronchovascular bundles and interlobular septa.” Radiopaedia
Incorrect Answers:
- a) “Centrilobular nodules are more commonly seen in small airway diseases such as hypersensitivity pneumonitis.” Radiopaedia
- c) “Tree-in-bud opacities suggest small airway disease with endobronchial infection.” Radiographics
- d) “Random nodules suggest hematogenous spread, such as in miliary tuberculosis.” Radiopaedia
- e) “Subpleural nodules are more commonly associated with fibrotic lung diseases like UIP.” Radiopaedia