Hunold P, Brandt-Mainz K, Freudenberg L, Vogt F M, Neumann T, Knipp S, Barkhausen J
Institut für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Essen.
Rofo. 2002 Jul;174(7):867-73. doi: 10.1055/s-2002-32697.
To compare contrast-enhanced magnetic resonance imaging (MRI) and positron emission tomography (PET) in the evaluation of myocardial viability.
[ (18)F]-FDG-PET, [ (201)Tl]-TlCl-SPECT and contrast-enhanced MRI were performed in 29 patients with proven coronary artery disease and impaired left ventricular function to assess myocardial viability. MRI scans were done on a 1.5 T scanner (Magnetom Sonata, Siemens, Germany). After the steady-state free precession cine study, 0.2 mmol/kg BW of Gd-DPTA (Magnevist(R), Schering, Germany) were administered i. v. For the detection of "late enhancement" (LE) indicating scar, left ventricular long axes and contiguous short axis slices of 8 mm thickness were scanned using an inversion recovery turbo gradient echo sequence (TR 8.0 ms; TE 4.0 ms; TI 180 - 240 ms; FA 20 degrees ). The evaluation of LE and FDG uptake in PET with perfusion defect in SPECT was done using an 8 (basal, mid) and 4 (apical) segment model in all short axes to cover the entire ventricle. The transmural extent of LE was assessed using a 4-point score system. Comparison between the two modalities was performed on a segmental basis.
A total of 1753 segments were assessed. In MRI, 40 % of the segments showed myocardial scar, whereas PET revealed impaired uptake in 25 %. MRI obtained a very low interobserver variability in detecting myocardial scar (kappa 0.92). Using PET as the standard of reference in the segmental comparison, contrast-enhanced MRI yielded a sensitivity of 84 % and a specificity of 76 % for the detection of scar. 18 % of all segments showed LE but normal FDG uptake, 83 % of them referred to subendocardial scars.
There is close agreement between contrast-enhanced MRI and PET in detecting transmural myocardial scars. Superior spatial resolution enables MRI to detect and quantify even subendocardial scar. Therefore, larger studies using functional recovery after revascularisation as an endpoint have to prove whether MRI might replace PET as the standard of reference in the assessment of myocardial viability.
比较对比增强磁共振成像（MRI）和正电子发射断层扫描（PET）在评估心肌存活性方面的作用。
对29例已证实患有冠状动脉疾病且左心室功能受损的患者进行[（18）F]-FDG-PET、[（201）Tl]-TlCl-SPECT和对比增强MRI检查，以评估心肌存活性。MRI扫描在1.5T扫描仪（德国西门子公司的Magnetom Sonata）上进行。在稳态自由进动电影研究后，静脉注射0.2mmol/kg体重的钆喷酸葡胺（德国先灵公司的Magnevist®）。为检测提示瘢痕的“延迟强化”（LE），使用反转恢复快速梯度回波序列（TR 8.0ms；TE 4.0ms；TI 180 - 240ms；FA 20°）扫描左心室长轴和8mm厚的连续短轴切片。在所有短轴上使用8段（基底、中间）和4段（心尖）模型评估PET中LE和FDG摄取与SPECT灌注缺损情况，以覆盖整个心室。使用4分评分系统评估LE的透壁范围。两种检查方法在节段基础上进行比较。
共评估了1753个节段。在MRI中，40%的节段显示心肌瘢痕，而PET显示摄取受损的节段占25%。MRI在检测心肌瘢痕方面观察者间变异性非常低（kappa 0.92）。在节段比较中以PET作为参考标准，对比增强MRI检测瘢痕的敏感性为84%，特异性为76%。所有节段中有18%显示LE但FDG摄取正常，其中83%为心内膜下瘢痕。
对比增强MRI和PET在检测透壁心肌瘢痕方面具有高度一致性。卓越的空间分辨率使MRI能够检测甚至量化心内膜下瘢痕。因此，以血运重建后功能恢复作为终点的更大规模研究必须证明MRI是否可替代PET作为评估心肌存活性的参考标准。
