Editing Single-photon emission computed tomography (section)

===Myocardial perfusion imaging===
{{More citations needed section|date=January 2014}}
{{main|Myocardial perfusion imaging}}
Myocardial perfusion imaging (MPI) is a form of functional cardiac imaging, used for the diagnosis of [[ischemic heart disease]]. The underlying principle is that under conditions of stress, diseased [[myocardium]] receives less blood flow than normal myocardium. MPI is one of several types of [[cardiac stress test]].

A cardiac specific radiopharmaceutical is administered, e.g., <sup>99m</sup>Tc-[[tetrofosmin]] (Myoview, GE healthcare), <sup>99m</sup>[[Technetium (99mTc) sestamibi|Tc-sestamibi]] (Cardiolite, Bristol-Myers Squibb) or [[Thallium-201]] chloride. Following this, the heart rate is raised to induce myocardial stress, either by exercise on a [[Treadmill#Exercise treadmills|treadmill]] or pharmacologically with [[adenosine]], [[dobutamine]], or [[dipyridamole]] ([[aminophylline]] can be used to reverse the effects of dipyridamole).

SPECT imaging performed after stress reveals the distribution of the radiopharmaceutical, and therefore the relative blood flow to the different regions of the myocardium. Diagnosis is made by comparing stress images to a further set of images obtained at rest which are normally acquired prior to the stress images.

MPI has been demonstrated to have an overall accuracy of about 83% ([[Sensitivity (tests)|sensitivity]]: 85%; [[Specificity (tests)|specificity]]: 72%) (in a review, not exclusively of SPECT MPI),<ref>{{cite journal|pmid=12468513|year=2002|last1=Elhendy|first1=A|last2=Bax|first2=JJ|last3=Poldermans|first3=D|title=Dobutamine stress myocardial perfusion imaging in coronary artery disease.|volume=43|issue=12|pages=1634–46|journal=Journal of Nuclear Medicine|url=http://jnm.snmjournals.org/content/43/12/1634.full}}</ref> and is comparable with (or better than) other non-invasive tests for ischemic heart disease.