1. What is the general size criterion for diagnosing lymphadenopathy in the chest on CT imaging?
A. Short-axis diameter >8 mm
B. Short-axis diameter >10 mm
C. Long-axis diameter >15 mm
D. Long-axis diameter >20 mm
Answer: B. Short-axis diameter >10 mm
Comment: A short-axis diameter >10 mm is considered the standard threshold for abnormal lymph nodes, except for the subcarinal region, where >12 mm is the criterion.
“On CT, mediastinal and hilar lymph nodes are considered abnormal if their short-axis diameter exceeds 10 mm, except in the subcarinal region, where >12 mm is the threshold.”
Reference: Fleischner Society Glossary
2. Which of the following is most commonly associated with psammommatous calcifications in thoracic lymph nodes?
A. Sarcoidosis
B. Papillary thyroid carcinoma
C. Silicosis
D. Tuberculosis
Answer: B. Papillary thyroid carcinoma
Comment: Psammommatous calcifications are strongly linked to metastases from papillary thyroid carcinoma or mucinous adenocarcinomas.
“Psammommatous calcifications, seen as lamellated round structures, are characteristic of papillary thyroid carcinoma and some mucinous adenocarcinomas.”
Reference: Radiographics: Thoracic Calcifications
3. Eggshell calcification in mediastinal lymph nodes is most commonly associated with which condition?
A. Lymphoma
B. Sarcoidosis
C. Tuberculosis
D. Metastatic disease
Answer: B. Sarcoidosis
Comment: While eggshell calcifications are seen in silicosis, sarcoidosis is a more common cause in the chest and thoracic lymph nodes.
“Eggshell calcification, characterized by thin peripheral calcification of lymph nodes, is commonly seen in sarcoidosis, though it may also occur in silicosis or post-radiation changes.”
Reference: PubMed: Eggshell Calcifications
4. Which of the following is a typical feature of necrotic lymph nodes on CT imaging?
A. Central hypodensity with rim enhancement
B. Uniformly hyperdense appearance
C. Psammommatous calcifications
D. Eggshell calcifications
Answer: A. Central hypodensity with rim enhancement
Comment: Central necrosis and rim enhancement on CT are hallmark features of necrotic lymph nodes, common in infections and aggressive malignancies.
“Necrotic lymph nodes appear hypodense centrally on CT, often with rim enhancement, indicating necrosis within the node.”
Reference: Radiopaedia: Necrotic Nodes
5. In which of the following conditions are low-density lymph nodes most commonly seen?
A. Lymphoma and tuberculosis
B. Silicosis and sarcoidosis
C. Metastatic thyroid carcinoma and amyloidosis
D. Pulmonary embolism and congestive heart failure
Answer: A. Lymphoma and tuberculosis
Comment: Low-density lymph nodes typically indicate central necrosis, often seen in tuberculosis or aggressive malignancies like lymphoma.
“Low-density lymph nodes are associated with central necrosis, frequently observed in infectious causes like tuberculosis or aggressive malignancies such as lymphoma.”
Reference: PubMed: Lymph Node Imaging
6. Which lymph node pattern is most indicative of amyloidosis on imaging?
A. Eggshell calcifications
B. Lobulated calcifications with soft tissue masses
C. Central hypodensity with peripheral enhancement
D. Diffuse uniform enlargement with irregular calcifications
Answer: D. Diffuse uniform enlargement with irregular calcifications
Comment: Amyloidosis affecting lymph nodes often presents as diffuse enlargement with irregular or lobulated calcifications, caused by amyloid protein deposition.
“Amyloidosis affecting lymph nodes often presents with diffuse enlargement and irregular calcifications, reflecting the deposition of amyloid proteins in nodal tissue.”
Reference: Radiographics: Thoracic Calcifications in Amyloidosis
7. What feature differentiates lymph nodes affected by carcinoma from those affected by lymphoma on imaging?
A. Carcinoma nodes are soft and compressible
B. Lymphoma nodes have central necrosis
C. Carcinoma nodes are hard and obstruct early
D. Lymphoma nodes are uniformly calcified
Answer: C. Carcinoma nodes are hard and obstruct early
Comment: Carcinoma nodes are firm and infiltrative, causing obstruction early, whereas lymphoma nodes are generally soft and compressible, obstructing only when significantly enlarged.
“Lymphoma nodes are generally soft and compressible, obstructing adjacent structures only when significantly enlarged, while carcinoma nodes are hard and infiltrative, causing obstruction even at smaller sizes.”
Reference: Fleischner Society Guidelines
8. Which of the following lymph node characteristics is most likely seen in metastatic mucinous adenocarcinoma?
A. Psammommatous calcifications
B. Eggshell calcifications
C. Central necrosis
D. Uniform hyperdensity
Answer: A. Psammommatous calcifications
Comment: Psammommatous calcifications, small and lamellated, are characteristic of metastatic mucinous adenocarcinomas and papillary thyroid carcinoma.
“Psammommatous calcifications are small, lamellated, rounded structures frequently associated with mucinous adenocarcinoma and papillary thyroid carcinoma.”
Reference: Radiographics: Thoracic Calcifications
9. What imaging modality is most useful for differentiating benign from malignant lymphadenopathy in the chest?
A. Chest X-ray
B. High-resolution CT
C. PET-CT
D. Ultrasound
Answer: C. PET-CT
Comment: PET-CT assesses metabolic activity, helping to distinguish benign from malignant lymphadenopathy, particularly in ambiguous cases.
“PET-CT is the modality of choice for assessing metabolic activity, providing a reliable means to distinguish benign from malignant lymphadenopathy.”
Reference: PubMed: PET-CT in Lymphadenopathy
10. What is the most common primary malignancy associated with psammommatous calcifications in thoracic lymph nodes?
A. Papillary thyroid carcinoma
B. Mucinous adenocarcinoma
C. Small cell lung cancer
D. Hodgkin’s lymphoma
Answer: A. Papillary thyroid carcinoma
Comment: Psammommatous calcifications are strongly associated with papillary thyroid carcinoma, which frequently produces these structures.
“Psammommatous calcifications in lymph nodes are strongly associated with papillary thyroid carcinoma, reflecting the tumor’s propensity for calcified deposits.”
Reference: Radiopaedia: Psammoma Bodies