In vivo evaluation of myocardial infarction by computed tomography: an experiment with electrocardiographic gating.

Retrospectively gated and ungated images of normal and 24 h post-infarction mini-pig hearts were obtained. The 11 imaged infarcts were transcatheter embolisation of the branches of the left anterior descending coronary artery. Using a contrast infusion technique and scanning during infusion, four infarcts were clearly detected as low-attenuation areas in the myocardium, one of these showing adjacent contrast enhancement. Two other infarcts showed as enhancing regions. Two small infarcts (0.8-1.0 cm3) were not detected and three others were in doubt. Streaking and other artefacts presented difficulties in image interpretation, which were sometimes resolved by gating. A comparison is made of these findings with those obtained from experiments with dogs, of comparable methodology. Differences are considered to result from anatomical differences between the two species, more particularly in the collateral blood supply to the myocardium.