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 chemistry, compressed helium is used as a carrier gas for an instrument called a Gas Chromatograph. Its role is propel other molecules through a long tube where they gradually separate and then are detected at the end. It is used because it is so inert and won't interfere with the molecules you're trying to detect. Compressed helium is also used to produce an extremely cold environment. Scientists can almost reach absolute zero with compressed helium. davenpoc Â· 7 years ago.