Chest radiograph - Abnormalities. 1  A pulmonary nodule is a discrete opacity in the lung which may be caused by... 2  Neoplasm: benign or malignant. 3  Granuloma: tuberculosis. 4  Infection: roundish pneumonia. 5  Vascular: infarct, varix, granulomatosis with polyangiitis, rheumatoid arthritis.
Helium is used for purposes that require some of its unique properties: its low density, low solubility, and high thermal conductivity. 7,000 tons, or 22%, of the total helium used involves the cooling of superconducting magnets in medical magnetic resonance imaging (MRI) scanners.
Blimps, dirigibles, zeppelins, anti-aircraft balloons, weather balloons and other lighter-than-air craft have all used helium as a lifting gas. It is much safer than hydrogen because it is not flammable. This was the most important category of helium use until the end of World War II. Much lower amounts of helium are now used as a lifting gas.