Cross-camera comparison of SPECT measurements of a 3-D anthropomorphic basal ganglia phantom
Cross-camera comparison of SPECT measurements of a 3-D anthropomorphic basal ganglia phantom
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DOI：
10.1007/s00259-005-0036-8
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发表时间：
2006-04-01
影响因子：
9.1
通讯作者：
Tatsch, K
中科院分区：
文献类型：
--
作者：
Koch, W;Radau, P;Tatsch, K
目的：脑内神经递质系统的SPECT检查必须在不同中心之间具有可比性，以产生一个全面的数据池，例如用于多中心研究。然而，具体设备对定量评价的影响以及相应的补偿方法还没有得到充分的研究。以前的研究表明，量化结果可能会因所使用的成像设备而显著不同，从而影响数据的临床解释。这项研究的目的是基于对拟人3D基底节体模的标准化测量来确定常见相机/准直器组合的校正系数，以补偿不同SPECT相机/准直器设备的影响。后者可作为人类研究多巴胺能系统的模型。方法：在商业模体(RSD Alderson)的纹状体和背景室内填充不同浓度的I-123，其特定的纹状体/背景比从0.6到16.1。这一设置是通过以下四种相机/准直器组合进行成像的：西门子Multispect3配备莱尔和I-123平行孔准直器，西门子ECAM配备莱尔平行孔准直器，飞利浦棱镜3000配备莱尔扇光束准直器，使用标准化的采集和重建协议。所有扫描都自动与体模的SPECT模板共同配准，并使用基于体模的CT扫描的3D感兴趣体积(VOI)图进行量化。将SPECT计算的所有纹状体/背景比值与井计数器中测量的真实比值进行比较。结果：采用二次多项式回归模型时，每个相机/准直器组合的真实比值和测量比值之间的关系可以用线性回归来充分描述，而没有相应的改进。回收率和标准误差分别为2.04+/-0.04、2.67+/-0.03、2.15+/-0.03和2.81+/-0.03。回收率从36%到49%。结论：用不同的成像设备测量3D基底节体模，测量的纹状体/背景比与实际的纹状体/背景比之间存在线性相关性。根据这些发现，如果采购、重建和评估充分标准化，在不同设备之间调整量化结果似乎是可能的。在体模和患者研究中使用相同的评估方法(可比较的VOI的形状、大小和位置)可能允许将计算的校正因子从体模转移到患者的多巴胺能系统的研究。
Purpose: SPECT examinations of neurotransmitter systems in the brain have to be comparable between centres to generate a comprehensive data pool, e.g. for multicentre studies. Equipment-specific effects on quantitative evaluations and corresponding methods for compensation, however, have been insufficiently examined. Previous studies have shown that quantitative results may vary significantly according to the imaging equipment used, thereby affecting clinical interpretation of the data. The aim of this study was to determine correction factors for common camera/collimator combinations based on standardised measurements of an anthropomorphic 3D basal ganglia phantom to compensate for the effects of different SPECT camera/collimator equipment. The latter may serve as a model for human studies of the dopaminergic system.Methods: The striatum and background chambers of a commercially available phantom (RSD Alderson) were filled with various I-123 concentrations encompassing specific striatum/background ratios from 0.6 to 16.1. This setup was imaged with the following four camera/collimator combinations: Siemens Multispect 3 fitted with LEHR and I-123 parallel-hole collimators, Siemens ECAM with LEHR parallel-hole collimators and Philips Prism 3000 fitted with LEHR fanbeam collimators, using standardised protocols for acquisition and reconstruction. All scans were automatically co-registered to a SPECT template of the phantom and quantified using a 3D volume of interest (VOI) map based on a CT scan of the phantom. All striatal/background ratios calculated by SPECT were compared with the true ratios calculated from the measurements in a well counter. Regression analyses were performed and recovery correction factors between measured and true ratios determined.REsults: The relation between true and measured ratios could be sufficiently described by a linear regression for each camera/collimator combination without relevant improvement when using second-order polynomial regression models. The recovery correction factors and standard errors were 2.04 +/- 0.04 for the Philips Prism 3000, 2.67 +/- 0.03 for the Siemens Multispect 3/LEHR parallel-hole collimators, 2.15 +/- 0.03 for the Siemens Multispect 3/I-123 collimators and 2.81 +/- 0.03 for the Siemens ECAM. Percentage recovery ranged from 36% to 49%.Conclusion: Measurements of a 3D basal ganglia phantom with various imaging devices revealed linear correlations between measured and true striatal/background ratios. Based on these findings, adjustment of quantitative results between different equipment seems possible, provided that acquisition, reconstruction and evaluation are adequately standardised. The use of identical evaluation methods in phantom and patient studies (comparable shape, size and location of the VOIs) might allow transfer of the calculated correction factors from phantom to studies of the dopaminergic system in patients.