Under imaging guidance, a needle-like applicator called a cryoprobe can be guided along a blood vessel or introduced directly through the skin to a target organ. Liquid nitrogen or argon gas is delivered through it to create intense cold to freeze and destroy diseased tissue, including cancer cells. It may be used to treat a variety of skin conditions as well as tumours within the liver, kidneys, bones, lungs and breasts or to destroy abnormally functioning electrical conducting tissue in the heart.