Preliminary Clinical Investigation On The Alterations Of ⁹⁹Tc^m-MIBI Washout Rates In Ischemia Myocardium

ObjectiveThe aim of this study was to investigate the changes in early and late washout rates of 99Tcm-methoxyisobutylisonitrile (MIBI) of ischemia heart disease (IHD), and its clinical application value in evaluating dysfuction of ischemia myocardial cell.MethodsThe patients who were clinically diagnosed as IHD with three-vessel stenosis (>50%) according to angiography(CAG) results among whom myocardial infarction patients excluded, underwent 99Tcm-MIBI static planar and gated single-photon emission computed tomography (SPECT) imaging. The early (90 minutes after the intravenous injection) and late (4 hours after the intravenous injection) washout rates of 99Tcm-MIBI and left ventricular ejection fraction(LVEF) between IHD group and normal control group were compared. Linear correlation analysis was made between the early and late washout rates and LVEF measured by gated SPECT.ResultsStatistically lower early washout rate of 99Tcm-MIBI was observed in IHD group than control group [(13.44±2.87)% vs (17.32±4.92)%, t=2.384, p<0.05], but statistically higher late washout rate of 99Tcm-MIBI was observed in IHD group than control group [(19.24±4.71)% vs (15.23±3.81)%, t=-2.246, p<0.05]. moreover, LVEF in IHD group was significantly lower than control group[(55.71±7.97)% vs (67.75±5.43)%, t=-4.418, p<0.01]; There is no correlations between the early and late washout rates and LVEF(r=-0.212, p>0.05; r=0.352, p>0.05, respectively). Conclutions99Tcm-sestamibi washout rates may reflect myocardial cell impairment due to ischemia in ischemia heart disease patients.