Cavitary lung lesions are frequent findings on imaging, mainly caused by malignancies and infections. CT scan provides more accurate diagnosis than conventional radiography. Cavities contain gas surrounded by variable thickness walls
Screening detects unrecognized conditions or risk markers in asymptomatic individuals. Aims to identify conditions that could become diseases earlier. Not all screening tests benefit individuals, leading to potential adverse effects
First synthesized in 1912, invented by A. Kachugin in 1949. First tested at Many Farms, Navajo community in Arizona. Initially used as antidepressant, discontinued in 1961 due to hepatotoxicity
Created by Ehrlich, modified by Ziehl and Neelsen in late 19th century. Initially used for tuberculosis diagnosis, later adapted for other mycobacteria
Alveoli are tiny balloon-shaped air sacs at lung bronchioles. One cubic millimeter contains around 170 alveoli. Surfactant fluid lines alveoli to maintain shape and facilitate gas exchange
Epidemic describes disease outbreak spreading rapidly in limited region. Pandemic refers to global epidemic affecting multiple countries or continents. Endemic describes constant presence of disease in geographic population