Pulmonary Infection Flashcards
community acquired pneumonia
S. pneumonia, also atypical pneumonias (Mycoplasma, viral, chlamydia), legionella, klebsiella and gram negatives
legionella pneumonia
elderly, severe infections
peripheral consolidations»_space; lobar/multifocal pneumonia
klebsiella and gram negative pneumonias
alcoholics/aspirators
voluminous inflammatory exudates; bulging fissure sign
hospital acquired pneumonia
aspiration of colonized secretions
typically MRSA and resistant gram negatives like pseudomonas
health care associated pneumonia
pneumonia >2 day hospitalization over past 90 days or nursin home
ventilator associated pneumonia
polymicrobial infection
pseudomonas and acinetobacter
pneumonia in immunocompromised patient
opportunistic infections: pneumocystis, Aspergillus, Nocardia, CMV
lobar pneumonia
consolidation in single lobe; air bronchograms
usually bacterial, CAP
lobular pneumonia/bronchopneumonia
patchy consolidation with poorly defined airspace opacities
s aureus
interstitial pneumonia
inflammatory cells in interstitial tissue»_space; diffuse/patchy ground glass opacification
mycoplasma, chlamydia, pneumocystis
round pneumonia
S. pneumonia, seen in children
infection confined to incomplete formation of pores of kahn
pneumonia complications
abscess, pulmonary gangrene, empyema, pneumatocele, bronchopleural fistula , emphyema necessitans
emphyema stages
free flowing exudative effusion > fibrous strands >solid/jelly-like fluid
split pleura sign; enhancement of visceral and parietal pleural layers
initial exposure to TB ?
contained disease (calcified granulomas/calcified hilar LN) vs primary TB (children/immunocompromised)
primary TB imaging manifestations
ill defined consolidation, pleural effusion, LN, miliary disease
typically lower or RML
Ghon focus
initial focus of infection, upper part of lower lobe, lower part of upper lob
Ranke complex
Ghon focus + LN
post primary/reactivation TB
adolescents/adults and caused by reactivation of dormant infection
chronic cough, low grade fever, hemoptysis, night sweats
upper lobe apical and posterior segments
imaging hallmarks of reactivation TB
upper lobe predominant disease, cavitation, lack of adenopathy; tree-in-bud suggests endobronchial spread
tuberculoma
well defined rounded opacity in upper lobes
healed TB
apical scarring, upper lobe volume loss, hilar retraction
calcified granulomas may be present as wel; containment of initial infection by delayed hypersensitivity response
miliary TB
random distribution of tiny nodules in hematogenously disseminated TB
primary or reactivation TB
atypical mycobacterial infection
elderly woman with cough, low grade fever, weight loss
Lady Windermere syndrome; usually Mycobacterium avium intracellulare or M kansaii
bronchiectasis and tree-in bud nodules in the RML/lingula
hot tub lung
hypersensitivity pneumonitis in response to atypical mycobacteria typically found in hoot tubs
centrilobular nodules
endemic fungi
histoplasma, coccidiodes, blastomyces
histoplasma
OH/MS river valleys, soil contaminated with bird/bat guano
calcified granuloma/histoplasmoma
may mimic reactivation TB
may cause fibrosing mediastinitis
coccidiodes immitis
SW US
multifocal consolidation, multiple pulmonary nodules, miliary nodules
blastomyces dermatitidis
central/SE US
flu-like illness that can progress to multifocal consolidation, ARDS, miliary disease
