Complex sentence: Xenon 133 (brand name Xeneisol) is a radionuclide that is inhaled to assess pulmonary function, and to image the lungs.
Split into simpler sentences: Xenon 133 (brand name Xeneisol) is an isotope of Xenon. It is a radionuclide that is inhaled to assess pulmonary function, and to image the lungs.