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.
In other areas of manufacturing, the goal may be simply to limit the use of helium. Lyttle pointed out the use of a CO2 laser for welding applications as an example. Traditionally, helium is used as a shielding gas in CO2 laser welding, but it is supplied in a less-than-efficient manner to the area.