A pulmonary nodule is a discrete opacity in the lung which may be caused by: 1  Neoplasm: benign or malignant. 2  Granuloma: tuberculosis. 3  Infection: roundish pneumonia. 4  Vascular: infarct, varix, granulomatosis with polyangiitis, rheumatoid arthritis.
1 Helium is also commonly used to pressurize and purge systems of unwanted gases. 2  It is also used in controlled atmospheres when the levels of different gases have to be kept constant. 3  It is used as a protective gas when growing silicon and germanium crystals and when producing titanium and zirconium.
Helium plasma technology has also found an application in abdominal and laparoscopic surgery. Helium plasma is being used in the thermal coagulation of tissues that clears the bleeding from the surgical field and enhances visualization of bleeding sites . The future of helium research Since the discovery of helium, the applications of helium have evolved greatly.