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.
Although helium is the second most abundant element in the universe, most of it in the Earth's atmosphere bleeds off into space. Helium used for industrial purposes is a byproduct of natural gas production, and the Texas Panhandle is the United States' helium capital.