[Selective coronary scintigraphy using labelled microspheres].

Selective intracoronary injection of microspheres labelled with radioactive substances which emit gamma rays with different energy levels (Indium 113 m and Technetium 99 m) allows us to explore by scintigraphic methods the areas of distribution of the two coronary arteries. Having been carefully calibrated, the particles are injected in limited numbers, and block the precapillary arterioles, where they gradually diminish in number. Scintigraphic examination is carried out in various projections (anteroposterior, left anterior oblique and right anterior oblique) immediately after coronary arteriography. Coronary scintigraphy allows us to establish the integrity of the distribution network of a coronary trunk which appears normal on coronary arteriography, to visualise the diminution of flow caused by a stenosed but patent trunk, and to visualise the extent of the collateral circulation and the quality of revascularisation achieved by an aorto-coronary bypass operation.