[Assessing myocardial viability in chronic myocardial infarct with 18F-fluoro-D-glucose positron emission tomography and 99mTc-MIBI SPECT].

The determination of residual viability in regions of myocardial infarcts is of considerable clinical interest. In order to assess residual viability in regions with chronic myocardial infarction, 18 patients with anterior myocardial infarcts and 14 patients with inferior myocardial infarcts as confirmed by ECG and cine ventriculography underwent 99mTc-methoxyisobutyl-isonitrile single photon emission computed tomography (MIBI-SPECT) and 18F-fluoro-D-glucose positron emission tomography (FDG-PET). Tracer uptake was quantified in 13 segments for each patient (a total of 416 segments). MIBI uptake was normalized to the maximal uptake in the heart, FDG uptake was normalized to the maximal uptake of left ventricular segments with normal contraction by cine ventriculography and without significant stenosis of the coronary artery supplying this region. MIBI-SPECT scar and FDG-PET scar were defined as tracer uptake of less than 2.5 SD below mean values of a healthy control group. Both methods scored 258 segments concordantly viable and 74 segments concordantly scar; 61 segments were scored scar by MIBI-SPECT and viable by FDG-PET, 23 segments were scored viable by MIBI-SPECT and scar by FDG-PET (p < 0.0001). In patients with anterior myocardial infarction, 136 segments were scored viable and 53 segments were scored scar by both methods, 29 segments were scored scar by MIBI-SPECT and viable by FDG-PET, 16 were scored discordantly viable by MIBI-SPECT and scar by FDG-PET (p < 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)