thallium scan
Last reviewed 01/2018
Myocardial perfusion scintigraphy uses a potassium analogue, thallium-201, to demonstrate areas of poorly perfused myocardium.
The investigation consists of a standard exercise test with continuous ECG and blood pressure monitoring. At peak exercise the thallium-201 is injected intravenously.
Areas of myocardium which are well perfused take up high levels of thallium while ischaemic areas appear as scintigraphic defects in the immediate post-exercise exposures.
Repeat imaging with the gamma-camera at 2-4 hr post-exercise permits reassessment of the scintigraphic defects:
- if the defect has resolved then the area was relatively ischaemic but still viable
- if the defect persists then the area has infarcted