# Texture-Based Analysis of \({}^{\bf 18}\)F-Labeled Amyloid PET Brain Images
## 3 Results  
Results from the Mann-Whitney U-test using global features are shown in Table 2. When comparing image features between A\(\beta\)+ and A\(\beta-\) patients independently of the used radiotracer and in the [18F]FBP group, all features show statistically significant differences except one. Correlation does not show significant differences between A\(\beta\)+ and A\(\beta-\) in any of the study groups (\(p\) = 0.037, \(p\) = 0.022 and \(p\) = 0.295, respectively). Additionally, energy and contrast are not significant features when analyzing the images acquired with [18F]FMM (\(p\) = 0.057 and \(p\) = 0.029, respectively). The results for the analyses of the individual VOIs for the three study groups are shown in Tables 3-5, respectively. Across all VOIs, the SUVR shows significant differences between A\(\beta\)+ and A\(\beta-\) for all three study groups, except in the occipital and left parietal VOIs in [18F]FBP images. Regarding HFs, energy and homogeneity show significant differences in 9 VOIs (all except the parietal and left anterior cingulate VOIs) for all patients, more than any other HF in that study group. In the case of [18F]FBP PET images, homogeneity is significantly different in 7 VOIs (left and right frontal and occipital VOIs, as well as the left PCC and right temporal and anterior cingulate VOIs). When analyzing only [18F]FMM PET images energy also shows significant differences in 7 VOIs (occipital, temporal and PCC, as well as right anterior cingulate VOIs). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Image Feature** & **All Patients** & **[18F]FBP** & **[18F]FMM** \\ \hline SUVR & **<0.001** & **0.011** & **<0.001** \\ Energy & **<0.001** & **0.001** & 0.057 \\ Contrast & **<0.001** & **0.001** & 0.029 \\ Entropy & **<0.001** & **0.001** & **0.019** \\ Homogeneity & **<0.001** & **0.001** & **0.019** \\ Correlation & 0.037 & 0.022 & 0.295 \\ Dissimilarity & **<0.001** & **0.001** & **0.027** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Differences between global image features of A\(\beta\)+ and A\(\beta-\) cases evaluated by Mann-Whitney U-tests. Significant False Discovery Rate (FDR)-adjusted \(p\)-values are given in bold. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Image Feature** & **Frontal** & **Occipital** & **Parietal** & **Temporal** & **PCC** & \multicolumn{3}{c}{**Anterior**} \\  & & & & & & & & & **Cingulate** & \\ \hline  & L & R & L & R & L & R & L & R & L & R \\ \hline SUVR & **<0.001** & **<0.001** & **0.005** & **0.007** & **0.003** & **0.001** & **0.001** & **<0.001** & **<0.001** & **<0.001** & **<0.001** & **0.003** \\ Energy & **0.020** & **0.002** & **<0.001** & **<0.001** & 0.253 & 0.776 & **0.003** & **0.001** & **0.032** & **<0.001** & 0.574 & **<0.001** \\ Contrast & **0.001** & **<0.001** & **<0.001** & 0.130 & 0.092 & **0.005** & **0.013** & **<0.001** & **<0.001** & 0.556 & 0.890 \\ Entropy & **<0.001** & **<0.001** & **<0.001** & 0.130 & 0.548 & **0.023** & **0.007** & 0.117 & **<0.001** & 0.592 & **0.001** \\ Homogeneity & **0.008** & **<0.001** & **<0.001** & **<0.001** & 0.188 & 0.786 & **0.001** & **<0.001** & **<0.001** & **<0.001** & 0.054 & **<0.001** \\ Correlation & 0.232 & **0.012** & 0.087 & 0.416 & 0.539 & 0.226 & **<0.001** & **0.020** & 0.092 & 0.697 & 0.488 & **0.001** \\ Dissimilarity & **0.001** & **<0.001** & **<0.001** & **<0.001** & 0.130 & 0.207 & **0.002** & **0.005** & **<0.001** & **<0.001** & 0.817 & 0.163 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Differences between volumes of interest (VOI) image features of A\(\beta\)+ and A\(\beta-\) of all 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). On the other hand, all image features are significantly different between A\(\beta+\) and A\(\beta-\) in the right frontal and temporal VOIs when grouping all patients.