# Texture-Based Analysis of \({}^{\bf 18}\)F-Labeled Amyloid PET Brain Images
## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Image Feature** & **Frontal** & **Occipital** & **Parietal** & **Temporal** & **PCC** &
\begin{tabular}{c} **Anterior** \\ **Cingulate** \\ \end{tabular} \\ \hline  & **L** & **R** & **L** & **R** & **L** & **R** & **L** & **R** & **L** & **R** \\ \hline SUVR & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** \\ Energy & 0.175 & 0.236 & **<0.001** & **<0.001** & 0.440 & 0.144 & **0.006** & **0.004** & **<0.001** & **<0.001** & 0.525 & **0.005** \\ Contrast & 0.038 & **0.009** & **<0.001** & **0.001** & 0.328 & 0.363 & 0.035 & **0.009** & **0.010** & **<0.001** & 0.718 & 0.986 \\ Entropy & **0.022** & 0.052 & **<0.001** & **0.001** & 0.236 & 0.718 & 0.032 & **0.003** & **<0.001** & **<0.001** & 0.503 & 0.035 \\ Homogeneity & 0.135 & 0.110 & **<0.001** & **<0.001** & 0.295 & 0.481 & **0.002** & **0.003** & **<0.001** & **<0.001** & 0.090 & 0.035 \\ Correlation & 0.904 & 0.175 & 0.118 & 0.400 & 0.850 & 0.279 & **0.009** & 0.061 & 0.932 & 0.823 & 0.250 & **0.001** \\ Dissimilarity & 0.035 & **0.024** & **<0.001** & **<0.001** & 0.295 & 0.503 & **0.012** & **0.006** & **0.006** & **<0.001** & 0.932 & 0.503 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Differences between VOI image features of A\(\beta+\) and A\(\beta-\) of [18F]FMM cases evaluated by Mann–Whitney U-tests. Significant \(p\)-values after FDR correction are given in bold. (L, left; R, right; PCC, combined posterior cingulate/precuneus). AUC values from ROC curves of the individual VOIs for the first study group are shown in Table 7. In the first study group with all cases, the SUVR shows in all VOIs AUCs > 0.7, except the left occipital VOI (0.698). The highest AUC is obtained with energy in the left occipital VOI (0.880). Additionally, dissimilarity shows AUC values > 0.7 or <0.3 in 8 VOIs (all except parietal and anterior cingulate VOIs). On the other hand, 6 of the 7 image features result in high AUC values in the right frontal, left occipital and temporal VOIs, as well as the right PCC, more than any other region. Tables 8 and 9 show the AUC values of the image features in the study groups after separating into images acquired with [18F]FBP and [18F]FMM. While image features extracted from the global VOI show better discriminatory performance in the [18F]FBP group than [18F]FMM, this trend is generally inversed when computing ROC curves with features from regional VOIs. Grouped by radiotracer, SUVR again results in AUC values > 0.7 in nearly every VOI, indicating that higher SUVRs are related to A\(\beta\)+. An exception are the right occipital (as in the previous study group) and left parietal VOIs in the [18F]FBP group. Moreover, the overall highest AUC is obtained with the SUVR in the left temporal VOI of the [18F]FMM group (0.989). Excluding the SUVR, the largest AUC is obtained also in the [18F]FMM group with energy in the right PCC VOI. The HF with the most VOIs (9 out of 12) with AUC values < 0.3 is entropy in the [18F]FMM group. Lastly,  
Figure 1: Receiver characteristic curves (ROC) curves representing the discriminatory capacity of the global standardized uptake value ratios (SUVR) and Haralick features (HFs) in separating A\(\beta\)+ and A\(\beta\) – cases. ROC curves for the three study groups: (**a**) all patients; (**b**) amyloid positron emission tomography (PET) images acquired with [18F]FBP; (**c**) amyloid PET images acquired with [18F]FMM. all features in the right frontal VOI of the [18]FJFB images and in the left temporal VOI of the [18]FJFMM group present AUC values > 0.7 or <0.3. Moreover, 3 VOIs (left occipital and PCC) in the [18]FJFBP group and 5 VOIs (occipital, right temporal and PCC) in the [18]FJFMM group result in AUC values > 0.7 or <0.3 with 6 out of 7 image features. In all cases, only correlation shows AUC values < 0.7.