Apostolova Ivayla, Schiebler Tassilo, Lange Catharina, Mathies Franziska Lara, Lehnert Wencke, Klutmann Susanne, Buchert Ralph
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
EJNMMI Phys. 2023 Mar 29;10(1):25. doi: 10.1186/s40658-023-00544-9.
The specific binding ratio (SBR) of I-FP-CIT in the putamen is widely used to support the interpretation of dopamine transporter (DAT) SPECT. Automatic methods for computation of the putamen SBR often include stereotactical normalization of the individual DAT-SPECT image to an anatomical standard space. This study compared using a single I-FP-CIT template image as target for stereotactical normalization versus multiple templates representative of normal and different levels of Parkinson-typical reduction of striatal I-FP-CIT uptake.
1702 clinical I-FP-CIT SPECT images were stereotactically normalized (affine) to the anatomical space of the Montreal Neurological Institute (MNI) with SPM12 either using a single custom-made I-FP-CIT template representative of normal striatal uptake or using eight different templates representative of normal and different levels of Parkinson-typical reduction of striatal FP-CIT uptake with and without attenuation and scatter correction. In the latter case, SPM finds the linear combination of the multiple templates that best matches the patient's image. The putamen SBR was obtained using hottest voxels analysis in large unilateral regions-of-interest predefined in MNI space. The histogram of the putamen SBR in the whole sample was fitted by the sum of two Gaussians. The power to differentiate between reduced and normal SBR was estimated by the effect size of the distance between the two Gaussians computed as the differences between their mean values scaled to their pooled standard deviation.
The effect size of the distance between the two Gaussians was 3.83 with the single template versus 3.96 with multiple templates for stereotactical normalization.
Multiple templates representative of normal and different levels of Parkinson-typical reduction for stereotactical normalization of DAT-SPECT might provide improved separation between normal and reduced putamen SBR that could result in slightly improved power for the detection of nigrostriatal degeneration.
壳核中I-FP-CIT的特异性结合率（SBR）被广泛用于辅助解释多巴胺转运体（DAT）单光子发射计算机断层扫描（SPECT）结果。壳核SBR的自动计算方法通常包括将个体DAT-SPECT图像立体定向归一化到解剖学标准空间。本研究比较了使用单个I-FP-CIT模板图像作为立体定向归一化的目标与使用多个代表正常以及不同程度帕金森病典型纹状体I-FP-CIT摄取减少的模板。
使用统计参数映射（SPM）12将1702例临床I-FP-CIT SPECT图像立体定向（仿射）归一化到蒙特利尔神经病学研究所（MNI）的解剖学空间，分别采用代表正常纹状体摄取的单个定制I-FP-CIT模板，或采用代表正常以及不同程度帕金森病典型纹状体FP-CIT摄取减少的八个不同模板，并进行有无衰减和散射校正。在后一种情况下，SPM找到与患者图像最佳匹配的多个模板的线性组合。壳核SBR通过在MNI空间中预定义的大的单侧感兴趣区域内使用最热体素分析获得。整个样本中壳核SBR的直方图用两个高斯分布的和进行拟合。通过计算两个高斯分布均值之差除以合并标准差得到的效应量来估计区分降低的和正常的SBR的效能。
对于立体定向归一化，使用单个模板时两个高斯分布之间的效应量为3.83，使用多个模板时为3.96。
用于DAT-SPECT立体定向归一化的代表正常以及不同程度帕金森病典型减少的多个模板可能会改善正常和降低的壳核SBR之间的区分度，这可能会略微提高检测黑质纹状体变性的效能。
