Balancing bias, reliability, noise properties and the need for parametric maps in quantitative ligand PET:: [11C]diprenorphine test-retest data
Balancing bias, reliability, noise properties and the need for parametric maps in quantitative ligand PET:: [11C]diprenorphine test-retest data
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DOI：
10.1016/j.neuroimage.2007.06.035
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发表时间：
2007-10-15
期刊：
影响因子：
5.7
通讯作者：
Koepp, Matthias J.
中科院分区：
文献类型：
--
作者：
Hammers, Alexander;Asselin, Marie-Claude;Koepp, Matthias J.
[(11)C]双丙诺啡(DPN)是一种非亚型选择性阿片受体PET配体，动力学缓慢，无特异性结合区域。参数贴图是理想的，但必须克服体素级别的高噪波。我们获得了常规光谱分析的参数值、参数图图像质量、重测重复性和可靠性(使用组内相关系数(ICCs))和一种派生方法(秩整形)，将它们与通过对动态数据集进行感兴趣体积(VOI)采样获得的值进行比较，并测试较少量的放射性注入是否保持了可靠性。10名受试者两次注射185MBq或135MBq的[(11)C]DPN，然后进行90min的动态PET。采用逐帧配准的方法对数据进行运动校正。建立了经放射性标记代谢物校正的动脉血浆输入函数。除了一名有实质性运动的受试者，其重测差值下降了约50%外，没有运动矫正的整体效果。实际参数值在很大程度上取决于慢频的截止频率(在0.0008 S(-1)到0.00063 S(-1)之间)。当使用常规光谱分析时，在有限的基本范围内图像质量令人满意。等级整形方法允许最大化这一范围，但也有类似的偏差。基于VOI的方法在地区之间具有最大的动态范围。对于基本范围受限的参数图，平均重测百分比差异最小；类似地，这些参数图的ICC最高(最高可达0.86)，但对于低剂量注射放射(0.24/0.04)的VOI导出的VD估计，ICC低得令人无法接受。我们的数据可以为特定生物学问题的方法论选择提供信息。(C)2007 Elsevier Inc.保留所有权利。
[(11)C]diprenorphine (DPN) is a non-subtype selective opioid receptor PET ligand with slow kinetics and no region devoid of specific binding. Parametric maps are desirable but have to overcome high noise at the voxel level. We obtained parameter values, parametric map image quality, test-retest reproducibility and reliability (using intraclass correlation coefficients (ICCs)) for conventional spectral analysis and a derived method (rank shaping), compared them with values obtained through sampling of volumes of interest (VOIs) on the dynamic data sets and tested whether smaller amounts of radioactivity injected maintained reliability. Ten subjects were injected twice with either similar to 185 MBq or similar to 135 MBq of [(11)C]DPN, followed by dynamic PET for 90 min. Data were movement corrected with a frame-to-frame co-registration method. Arterial plasma input functions corrected for radiolabelled metabolites were created. There was no overall effect of movement correction except for one subject with substantial movement whose test-retest differences decreased by similar to 50%. Actual parametric values depended heavily on the cutoff for slow frequencies (between 0.0008 s(-1) and 0.00063 s(-1)). Image quality was satisfactory for restricted base ranges when using conventional spectral analysis. The rank shaping method allowed maximising of this range but had similar bias. VOI-based methods had the widest dynamic range between regions. Average percentage test-retest differences were smallest for the parametric maps with restricted base ranges; similarly ICCs were highest for these (up to 0.86) but unacceptably low for VOI-derived VD estimates at the low doses of injected radioactivity (0.24/0.04). Our data can inform the choice of methodology for a given biological problem. (c) 2007 Elsevier Inc. All rights reserved.