正电子发射断层扫描心肌代谢显像定量评价陈旧性心肌梗死患者左心室心肌重构程度的研究

Quantitative Evaluation of Left Ventricular Remodeling Using ^(18)F-FDG Photon Emission Tomography Imaging in Patients With Old Myocardial Infarction

目的:采用自主开发的新软件和门控18F-脱氧葡萄糖正电子发射断层扫描(18F-FDG PET)心肌代谢显像对陈旧性心肌梗死患者的左心室心肌整体重构程度和局部重构程度进行无创性定量化评价。方法:纳入33例在本院行99Tcm-甲氧基异丁基异腈单光子发射断层扫描(99Tcm-MIBI SPECT)心肌灌注显像和门控18F-FDG PET心肌代谢显像评价心肌存活性,并在两周内行磁共振成像(MRI)检查的陈旧性心肌梗死患者(包括21例左心室室壁瘤患者)进行回顾性分析。采用基于矩阵实验室编程语言开发一套新软件,获得评价左心室整体重构程度的球形指数(SI),并首次提出评价左心室局部重构程度的新指标:水平长轴"倒八字"程度指数(DPI)、短轴横径比和短轴纵径比。左心室重构整体重构程度以磁共振成像测定的左心室舒张末期容积(LVEDV),左心室收缩末期容积(LVESV)为"金标准"。有经验的专家对PET心肌代谢显像水平长轴和垂直长轴显示"倒八字"程度采用4分打分法。分别将SI值与磁共振成像获取的LVEDV、LVESV和左心室射血分数(LVEF)进行相关性分析;对DPI值、短轴横径比和短轴纵径比与专家对"倒八字"程度的打分结果进行相关性分析。结果:SI值与磁共振成像获取的LVEDV和LVESV呈显著正相关(r分别为0.598和0.615,P均<0.01),与LVEF呈显著负相关(r=-0.587,P<0.01)。水平长轴左心室近前壁和中间段测定的DPI以及短轴测定的横径比与专家打分的结果呈显著正相关(r分别为0.763、0.709和0.722,P均<0.01)。结论:采用我们自主开发的新软件,通过对门控PET心肌代谢显像重建图像,可以较为客观地评价左心室整体的重构程度和局部的重构程度。

Objective： To quantitatively and non-invasively evaluate both global and local left ventricular remodeling （LVRM） in patients with old myocardial infarction by18F-FDG photon emission tomography （PET） imaging with self developed soft ware. Methods： A total of 33 patients received ^99Tc^m-MIBI SPECT and gated ^18F-FDG PET/CT imaging and MRI within 2 weeks in our hospital were retrospectively studied. There were 21 patients with LV aneurysm and 12 with old myocardial infarction. A new developed software based on Matrix laboratory language was used to quantitatively evaluate the degree of global LVRM by spherical index （SI）, and first used an index for quantitatively evaluate the degree of local LVRM including the divergent pattern index （DPI） on the horizontal long-axis （HLA） and horizontal diameter ratio （HDR） on the short axis. MRI measured left ventricular end-diastolic volume （LVEDV） and LVESV was defined as ＂golden standard＂ for evaluating the degree of global RM. The degree of ＂divergent pattern＂ was visually analyzed by 2 experienced experts with a 4 points scoring system （1-4 score） based on the long horizontal axis and the long vertical axis of PET imaging. The relationships between SI and MRI measured LVEDV, LVESV and LVEF were analyzed; meanwhile, the relationships between the experts visual scoring and DPI, HLA and HDR were studied. Results： For global RM study, SI was positively related to LVEDV and LVESV （r=0.598, P〈0.01 and r=0.615, P〈0.01）, negatively related to LVEF （t=-0.587, P〈0.01）; for local RM study, the experts visual scoring was positively related to DPI of anterior-HLA （r- 0.763, P〈0.01）, middle-HLA （r=0.709, P〈0.01） and HDR on short axis （r=0.722, P〈0.01）. Conclusion： Self developed new index of SI, DPI and HDR for PET myocardial metabolic imaging could evaluate both global and local degrees of LVRM in patients with old myocardial infarction.