A new short-lived isotope — "milked" from a "cow" of tin —is being used experimentally and clinically for lung, liver, and blood pool scanning.
A "cow," in the jargon of nuclear medicine, is a device generating ( milking) a new nuclide from the decay products of a more stable one. Latest of the herd is an isotope of indium (113mIn), derived from radioactive tin (113Sn).
Two speakers at a symposium on scanning touched on apparent advantages of113mIn, developed and first used at Johns Hopkins and being investigated at Syracuse, Chicago, and Northwestern Universities, among others.
About 90% of the administered dose concentrates in the lung when the isotope is given in an iron hydroxide solution, intravenously. For liver scans,113mIn is given as a colloid; it is bound to the patient's own beta globulin for placental and cardiac scanning.
Half-life of the isotope is only 1.7