Knuesel Patrick R, Nanz Daniel, Wyss Christophe, Buechi Martin, Kaufmann Philip A, von Schulthess Gustav K, Lüscher Thomas F, Schwitter Juerg
Division of Cardiology, University Hospital Zurich, Zurich, Switzerland.
Circulation. 2003 Sep 2;108(9):1095-100. doi: 10.1161/01.CIR.0000085993.93936.BA. Epub 2003 Aug 25.
Metabolic assessment of dysfunctional myocardium by PET allows prediction of functional recovery after revascularization. Contrast-enhanced MR (ce-MR) discriminates transmural distribution of viable and scar tissue with excellent spatial resolution. Both techniques were applied in ischemic chronic left ventricular dysfunction to relate metabolism and tissue composition to changes of contractile function after revascularization.
Nineteen patients with myocardial infarctions (>3 months) were studied by MR and PET, and 10 patients were followed by MR 11+/-2 months after revascularization. In 56 to 64 segments/heart, systolic wall thickening, viable mass, and thickness of viable rim tissue were determined by MR (inversion-recovery MR with 0.25 mmol/kg Gd-chelate). [18F]Fluorodeoxyglucose (FDG) uptake and resting perfusion (13N-ammonia) were determined by PET. Viable tissue per segment on ce-MR correlated with FDG uptake per segment (r=0.62 and 0.82 for segments with and without flow metabolism mismatch, P<0.0001). FDG uptake > or =50% (a predictor of functional recovery) corresponded to a viable rim thickness of 4.5 mm on ce-MR. Thick (>4.5 mm) and metabolically viable segments (> or =50% FDG uptake) showed functional recovery in 85%, whereas thin metabolically nonviable segments improved function in 13% (P<0.0005). Metabolically viable segments with a thin viable rim and thick segments with reduced FDG uptake improved function in only 36% and 23% of segments, respectively (NS versus thin metabolically nonviable). In these 2 classes of segments, scar per segment was higher than in thick viable segments (P<0.0001).
Metabolism and tissue composition discriminate various classes of dysfunctional myocardium. Most metabolically viable segments with a thick viable rim on ce-MR recover function after revascularization, whereas all other classes showed low recovery rates of contractile function.
通过正电子发射断层扫描（PET）对功能失调心肌进行代谢评估，有助于预测血运重建后功能的恢复情况。对比增强磁共振成像（ce-MR）能够以出色的空间分辨率区分存活心肌组织和瘢痕组织的透壁分布。这两种技术均应用于缺血性慢性左心室功能障碍，以关联代谢、组织构成与血运重建后收缩功能的变化。
对19例心肌梗死（>3个月）患者进行了磁共振成像和PET检查，其中10例患者在血运重建后11±2个月接受了磁共振成像随访。通过磁共振成像（使用0.25 mmol/kg钆螯合物的反转恢复磁共振成像）测定56至64个节段/心脏的收缩期室壁增厚、存活心肌质量和存活边缘组织厚度。通过PET测定[18F]氟脱氧葡萄糖（FDG）摄取和静息灌注（13N-氨）。ce-MR上每个节段的存活组织与PET上每个节段的FDG摄取相关（有和无血流代谢不匹配的节段，r分别为0.62和0.82，P<0.0001）。ce-MR上FDG摄取≥50%（功能恢复的预测指标）对应于存活边缘厚度为4.5 mm。厚（>4.5 mm）且代谢存活的节段（FDG摄取≥50%）中85%显示功能恢复，而薄的代谢无存活节段中13%功能改善（P<0.0005）。代谢存活但存活边缘薄的节段和FDG摄取降低的厚节段，分别仅有36%和23%的节段功能改善（与薄的代谢无存活节段相比无统计学差异）。在这两类节段中，每个节段的瘢痕高于厚的存活节段（P<0.0001）。
代谢和组织构成可区分不同类型的功能失调心肌。ce-MR上大多数代谢存活且存活边缘厚的节段在血运重建后功能恢复，而所有其他类型的收缩功能恢复率较低。
