Radiologic Findings Flashcards
What is “tree in bud” sign on CT? What does it suggest?
Tree-in-bud sign or pattern describes the CT appearance of multiple areas of centrilobular nodules with a linear branching pattern. Although initially described in patients with endobronchial tuberculosis, it is now recognized in a large number of conditions.
Causes include:
infective bronchiolitis
bacterial pneumonia, e.g. Staphylococcus aureus, Haemophilus influenzae, Mycobacterium tuberculosis, Mycobacterium avium (MAIC)
viral pneumonia
fungal pneumonia, e.g. aspergillus
allergic bronchopulmonary aspergillosis (ABPA)
pneumocystis pneumonia
congenital
cystic fibrosis
immotile cilia syndrome, e.g. Kartagener syndrome
yellow nail syndrome
connective tissue disorders
rheumatoid arthritis (RA)
Sjögren syndrome
bronchial
obliterative (constrictive) bronchiolitis
diffuse panbronchiolitis
follicular bronchiolitis
neoplastic (i.e. carcinomatous endarteritis 3,6,7 or bronchovascular interstitial infiltration 4,5)
bronchioloalveolar cell carcinoma
distant metastatic disease (e.g. breast, liver, ovary, prostate, kidney)
primary pulmonary lymphoma 5
chronic lymphocytic leukemia 4
What is the differential of a cavitary lung lesion?
Infections:
Pulmonary Abscess
Septic Emboli
Mycobacterium Tuberculosis Infection
Non-tuberculous Mycobacterial (NTMB) Infection (M. avium-intracelluare and M. kansaii.)
Aspergillosis (other fungal infections less commonly)
Systemic Diseases:
Granulomatosis with Polyangiitis (previously Wegner’s)
Rheumatic Nodules
Sarcoidosis
Malignancies (Wall thickness greater than 24 mm as well as perilesional consolidation may indicate malignancy, of all bronchial carcinoma’s 5-10% are cavitary)
Pulmonary metastasis from squamous cell carcinomas, mainly from the gastrointestinal tract and breast, sarcomas, and adenocarcinomas frequently cavitate
Entities That Overlap with Cystic Diseases:
Langerhans cell histiocytosis (LCH),
lymphangioleiomyomatosis (LAM),
lymphocytic interstitial pneumonia (LIP),
and findings of pneumocystis jirovecii infection are all cystic lung diseases
What is the name of the sign for epiglottis?
The thumbprint sign is a finding on a lateral cervical spine radiograph that suggests the diagnosis of epiglottitis. The sign is caused by a thickened free edge of the epiglottis, which causes it to appear more radiopaque than normal, resembling the distal thumb.
