An ion is an atom or group of atoms that has an electric charge. Ions with a positive charge are called cations. Ions with a negative charge are called anions.

Many normal substances exist in the body as ions. Common examples include sodium, potassium, calcium, chloride, and bicarbonate. (See: Electrolytes)

Ions can be created using radiation such as x-rays. Ionizing radiation is often used for diagnostic or therapeutic procedures, since the ions that are produced can be used to scan for or treat some diseases.

Related topics:

  • Adrenal medullary imaging
  • Bone scan
  • Gall bladder radionuclide scan
  • Gallium (GA) scan
  • Isotope study
  • Liver scan
  • Lung gallium (GA) scan
  • Nuclear ventriculography (MUGA or RNV)
  • Pulmonary ventilation/perfusion scan
  • Radiation therapy
  • Radioactive iodine uptake
  • Radionuclide cystogram
  • Renal venogram
  • RHISA scan
  • Thyroid scan
  • WBC (nuclear) scan

Alternative Names

Cations; Anions