^（99m）Tc－MIBISPECT检测梗塞区存活心肌（与^（18）F－FDGPET结果比较）

DETECTION OF VIABILITY IN THE REGIONS OF MYOCARDIAL INFARCTION BY SPECT MIBI:COMPARISON WITH THE RESULTS OF PET/ FDG

评价９９ｍＴｃ-甲氧基异丁基异腈（ＭＩＢＩ）ＳＰＥＣＴ定量分析在心肌梗塞（ＭＩ）区存活心肌判断中的准确性，及视觉判断９９ｍＴｃ-ＭＩＢＩＳＰＥＣＴ结果在缺血与坏死心肌鉴别中的局限性．方法：３４例ＭＩ患者进行了９９ｍＴｃ-ＭＩＢＩＳＰＥＣＴ心肌灌注显像及１８Ｆ标记的脱氧葡萄糖（ＦＤＧ）ＰＥＴ显像．结果：当局部心肌９９ｍＴｃ-ＭＩＢＩ放射性小于左室心肌峰计数的４０％，存活心肌存在的可能性仅为２４％左右；相反，当局部９９ｍＴｃ-ＭＩＢＩ放射性大于左室心肌峰计数的４０％，则９０％以上的心肌节段均为存活心肌．故视觉判断不可逆性缺损明显低估存活心肌．约５９％的不可逆性缺损节段在ＰＥＴ显像中有明确１８Ｆ-ＦＤＧ摄取，提示为存活心肌．结论：９９ｍＴｃ-ＭＩＢＩＳＰＥＣＴ定量分析能明显提高存活心肌的定位诊断，慎重判断及定义心肌灌注显像中的不可逆性缺损区，重视定量分析的研究及应用对ＭＩ区存活与坏死心肌的鉴别诊断有重要价值．

PURPOSE We compared and evaluated the visual and quantitative analysis of single photon emission tomography (SPECT) with 99mTc-MIBI (SPECT / MIBI) for detecting viability in the regions of myocardial infarction based on the criteria of positron emission tomography with 18F-deoxy-d-glucose (PET/FDG). METHODS 34 patients with myocardial infarction underwent both SPECT/ MIBI and PET/ FDG, followed by quantitative analysis.RESULTS In the myocardial segments of left ventricle with < 40% of peak activity by SPECT / MIBI, the possibilityof viability was 24%. In contrast, the possibility of viability was more than 90% in the segments with >40% of peak 99mTc-MIBI activity. On the other hand, visual analysis of SPECT/ MIBI underestimated viable myocardium. Since 59% of irreversible defects showed FDG uptake in PET/ FDG. CONCLUSIONS Care should be taken to define the significance of irreversible defects in visual analysis of SPECT / MIBI and quantitative analysis of SPECT/ MIBI is useful for detecting viable myocardium.