Airways

Question 1

Causes of tracheal thickening, SPARING posterior membrane

Answer 1

Relapsing polychondritis - smooth thickening, middle aged (women>men), affects other cartilaginous structures in the body (ears, nasal septum - saddle nose, larynx, large joints), look for air-trapping on expiratory imaging

TPO (tracheobronchopathia osteochondroplastica) - nodular calcified thickening, older patients

Question 2

Causes of circumferential tracheal thickening, NO SPARING of posterior membrane

Answer 2

TB - smooth concentric thickening, long segment
Amyloidosis - IRREGULAR narrowing of airways (rare) +/- calcifications
Wageners - 20% of patients, SUBGLOTTIC**
Sarcoid - smooth –> nodular
Iatrogenic - intubation/trach, more focal

Question 3

Causes of bronchiectasis

CAPTAIn Kangaroo

Answer 3

• CF
• ABPA
• Post infection
• TB/atypical mycobacterium (MAC)
• Agammaglobulinemia
• Immunodeficiency
• Kartagener i.e. primary ciliary dyskinesia
• Mounier-Kuhn - tracheobronchiomegaly + williams syndrome

Question 4

Most common primary central airway tumours in adults

Answer 4

• SCC - more common, smokers
• Adenoid cystic carcinoma - usually younger patients (40s, not associated with smoking) - remember that there are minor salivary glands lining the airways, and this is common malignant tumour of minor salivary glands

Question 5

Imaging appearance of SCC

Answer 5

Polypoid mass in the airway lumen (can be smooth, nodular, ulcerated)

Question 6

Imaging appearance of adenoid cystic Ca

Answer 6

Submucosal mass infiltrating tracheal wall and adjacent fat; or circumferential tracheal/ bronchial wall thickening causing stenosis

Question 7

Most common bronchial tumour in children

Answer 7

Carcinoid - homogeneous arterial enhancement, occurs distal to carina

DDx: hemangioma, glomus tumour, mucoepidermoid ca,(all show avid enhancement)

Question 8

4 most common airway mets

Answer 8

Breast, renal, thyroid, lung (BReTh lung)

Question 9

Benign endobronchial lesions

Answer 9

• Papillomas (multiple - HPV, can cause cavitating nodules in the lungs)
• Chondroma (calcs)
• Hemangioma (peds), hamartoma
• Lipoma, leiomyoma

Question 10

Causes of obliterative bronchiolitis (i.e. constrictive bronchiolitis) and imaging findings

Answer 10

"CRITTS"
- Cryptogenic/idiopathic
- RA; + other CTDs
- Infection (viral, atypical)
- Transplant (heart, lung, stem cell)**
- Toxins - drugs (Penicillamine, gold) inhalation
- Sawyer James**
also, DIPNECH

Hyperinflation, mosaic perfusion, air trapping, bronchial wall thickening and bronchiectasis

Question 11

Features of Kartagener’s

Answer 11

• Bronchiectasis
• Situs inversus/ambiguous
• Chronic sinusitis, polyposis
• Infertility

Question 12

Causes of tracheomalacia

Answer 12

Kids:
Congential - prematurity
Acquired - protracted intubation, vascular rings**

Adults:
Intubation, trauma, surgery (i.e. tracheostomy), vascular rings, mediastinal tumours (i.e. goiter), inflammation (i.e. relapsing polychondritis)

*need expiratory imaging to make this diagnosis; decreased AP diameter by 50%

Question 13

Most common site of tracheal laceration

Answer 13

at junction of cartilaginous and membranous wall posterolaterally

• penetrating injuries more common in the upper trachea
• blunt tracheal injuries more common in lower airway within 2 cm of the carina (fixed position)

Question 14

What is the “ring sling” complex?

Answer 14

Association between congenital tracheal stenosis and pulmonary sling (25% of cases have pulmonary sling)

Also high association with cardiac abnormalities