Large Lung Volumes
Dharshan Vummidi, MD
Eric J. Stern, MD
DIFFERENTIAL DIAGNOSIS
Common
Pulmonary Emphysema
Asthma
Constrictive Bronchiolitis
Less Common
Lymphangioleiomyomatosis (LAM)
Langerhans Cell Histiocytosis
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
Radiographs: Pruning of central vascular markings vs. increased reticulation
Helpful Clues for Common Diagnoses
Pulmonary Emphysema
Centrilobular
Cigarette smokers
Upper lobe predominance
HRCT: Areas of abnormal low attenuation around centrilobular arteries, lack walls
Panlobular
α-1-antitrypsin deficiency, methylphenidate (Ritalin) crushed tablet IV injection
Diffuse emphysema with lower lung predominance
Decreased conspicuity of vessels
Asthma
Increased lung lucency and bronchial wall thickening
Mild hilar prominence due to transient pulmonary hypertension
HRCT: Bronchial wall thickening, mosaic perfusion, and air-trapping on expiratory scanning
Constrictive Bronchiolitis
Large or small lung volumes
Attenuation of pulmonary vasculature
HRCT: Mosaic perfusion and air-trapping on expiratory imaging
Bronchiectasis common
Helpful Clues for Less Common Diagnoses
Lymphangioleiomyomatosis (LAM)
Almost exclusively in women of child-bearing age
CXR: Fine reticular pattern
Fine cysts with no zonal predominance
Lung bases are involved
Chylous effusions and pneumothoraces
HRCT
