Editing Technetium (section)

===Nuclear medicine and biology===
{{Main|Technetium-99m}}
[[File:Basedow-vor-nach-RIT.jpg|thumb|upright|Technetium [[Nuclear medicine|scintigraphy]] of a neck of [[Graves' disease]] patient|alt=Upper image: two drop-like features merged at their bottoms; they have a yellow centre and a red rim on a black background. Caption: Graves' Disease Tc-Uptake 16%. Lower image: red dots on black background. Caption: 250 Gy (30mCi) + Prednison.]]

[[Technetium-99m]] ("m" indicates that this is a [[Nuclear isomer#Metastable isomers|metastable]] nuclear isomer) is used in radioactive isotope [[nuclear medicine|medical tests]]. For example, technetium-99m is a [[radioactive tracer]] that medical imaging equipment tracks in the human body.<ref name="blocks" /><ref name="bbc-20150530" /> It is well suited to the role because it emits readily detectable 140&nbsp;[[Electronvolt|keV]] [[gamma ray]]s, and its half-life is 6.01&nbsp;hours (meaning that about 94% of it decays to technetium-99 in 24&nbsp;hours).<ref name="enc" /> The chemistry of technetium allows it to be bound to a variety of biochemical compounds, each of which determines how it is metabolized and deposited in the body, and this single isotope can be used for a multitude of diagnostic tests. More than 50 common [[radiopharmaceuticals]] are based on technetium-99m for imaging and functional studies of the [[Human brain|brain]], heart muscle, [[thyroid]], [[Human lung|lungs]], [[liver]], [[gall bladder]], [[kidney]]s, [[Human skeleton|skeleton]], [[blood]], and [[tumor]]s.{{sfn|Schwochau|2000|p=414}}

The longer-lived isotope, technetium-95m with a half-life of 61&nbsp;days, is used as a [[radioactive tracer]] to study the movement of technetium in the environment and in plant and animal systems.{{sfn|Schwochau|2000|pp=12–27}}