Partial-volume correction (PVC) using the Geometric Transfer Matrix (GTM) method is used in positron emission tomography (PET) to compensate for the effects of spatial resolution on quantitation. We evaluate the effect of misspecification of scanner point-spread function (PSF) on GTM results in amyloid imaging, including the effect on amyloid status classification (positive or negative). Twenty-nine subjects with Pittsburgh Compound B ([11C]PiB) PET and structural T1 MR imaging were analyzed. FreeSurfer 5.3 (FS) was used to parcellate MR images into regions-of-interest (ROIs) that were used to extract radioactivity concentration values from the PET images. GTM PVC was performed using our “standard” PSF parameterization [3D Gaussian, full-width at half-maximum (w) of approximately 5 mm]. Additional GTM PVC was performed with “incorrect” parameterizations, taken around the correct value. The result is a set of regional activity values for each of the GTM applications. For each case, activity values from various ROIs were combined and normalized to produce standardized uptake value ratios (SUVRs) for nine standard [11C]PiB quantitation ROIs and a global region. GTM operating-point characteristics were determined from the slope of apparent SUVR versus w curves. Errors in specification of w on the order of 1 mm (3D) mainly produce only modest errors of up to a few percent. An exception was the anterior ventral striatum in which fractional errors of up to 0.29 per millimeter (3D) of error in w were observed. While this study does not address all the issues regarding the quantitative strengths and weakness of GTM PVC, we find that with reasonable caution, the unavoidable inaccuracies associated with PSF specification do not preclude its use in amyloid quantitation.

中文翻译：

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[11C]PiB淀粉样蛋白成像中几何传递矩阵部分体积校正的点扩展函数规范误差的表征

使用几何传递矩阵 (GTM) 方法的部分体积校正 (PVC) 用于正电子发射断层扫描 (PET) 以补偿空间分辨率对定量的影响。我们评估了扫描仪点扩散函数 (PSF) 错误指定对淀粉样蛋白成像中 GTM 结果的影响，包括对淀粉样蛋白状态分类（阳性或阴性）的影响。分析了匹兹堡化合物 B ([11C]PiB) PET 和结构性 T1 MR 成像的 29 名受试者。FreeSurfer 5.3 (FS) 用于将 MR 图像分割为用于从 PET 图像中提取放射性浓度值的感兴趣区域 (ROI)。GTM PVC 使用我们的“标准”PSF 参数化 [3D 高斯，半高全宽 (w) 约 5 毫米] 进行。额外的 GTM PVC 使用“不正确”的参数化执行，取正确值。结果是每个 GTM 应用程序的一组区域活动值。对于每种情况，将来自不同 ROI 的活动值组合并标准化，以生成九个标准 [11C] PiB 定量 ROI 和全球区域的标准化摄取值比率 (SUVR)。GTM 工作点特性由表观 SUVR 与 w 曲线的斜率确定。w 规格中 1 毫米 (3D) 量级的误差主要只产生高达百分之几的适度误差。一个例外是前腹侧纹状体，其中观察到 w 误差高达每毫米 (3D) 0.29 的分数误差。虽然这项研究没有解决关于 GTM PVC 的定量优势和劣势的所有问题，