# New Approaches to AI Methods for Screening Cardiomegaly on Chest Radiographs
## 3 Results
### Cardiothoracic Ratio
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline
**Cardiomegaly Definition Based on CMR** & **Method of Measurements** & **P** & **N** & **TP** & **TN** & **FP** & **FN** & **Sensitivity** & **Specificity** & **Accuracy** \\ \hline \multirow{4}{*}{Both elevated LVEDV and enlarged LVM} & Manual reading & 38 & 12 & 14 & 12 & 0 & 24 & 36.84\% & 100.00\% & 52.00\% \\ \cline{2-10}  & Manual segmentation & 38 & 12 & 21 & 10 & 2 & 17 & 55.26\% & 83.33\% & 62.00\% \\ \cline{2-10}  & Automatic segmentation & 38 & 12 & 23 & 9 & 3 & 15 & 60.53\% & 75\% & 64.00\% \\ \cline{2-10}  & Manual reading & 37 & 13 & 14 & 13 & 0 & 23 & 37.85\% & 100\% & 54.00\% \\ \cline{2-10}  & Manual segmentation & 37 & 13 & 21 & 11 & 2 & 16 & 56.76\% & 84.62\% & 64.00\% \\ \cline{2-10}  & Automatic segmentation & 37 & 13 & 23 & 10 & 3 & 14 & 62.16\% & 76.92\% & 66.00\% \\ \hline \multirow{4}{*}{Elevated LVEDV} & Manual reading & 16 & 34 & 12 & 32 & 2 & 4 & 75.0\% & 94.12\% & 88.00\% \\ \cline{2-10}  & Manual segmentation & 16 & 34 & 14 & 25 & 9 & 2 & 87.5\% & 73.53\% & 78.00\% \\ \cline{2-10}  & Automatic segmentation & 16 & 34 & 13 & 21 & 13 & 3 & 81.25\% & 61.76\% & 68.00\% \\ \cline{2-10}  & Manual reading & 37 & 13 & 14 & 13 & 0 & 23 & 37.84\% & 100\% & 54.00\% \\ \cline{2-10}  & Manual segmentation & 37 & 13 & 20 & 10 & 3 & 17 & 54.05\% & 76.92\% & 60.00\% \\ \cline{2-10}  & Automatic segmentation & 37 & 13 & 22 & 9 & 4 & 15 & 59.46\% & 69.23\% & 62.00\% \\ \hline \multirow{4}{*}{Elevated LVEDV/BSA} & Manual reading & 17 & 33 & 12 & 31 & 2 & 5 & 70.59\% & 93.94\% & 86.00\% \\ \cline{2-10}  & Manual segmentation & 17 & 33 & 14 & 24 & 9 & 3 & 82.35\% & 72.73\% & 76.00\% \\ \cline{2-10}  & Automatic segmentation & 17 & 33 & 15 & 22 & 11 & 2 & 88.24\% & 66.67\% & 74.00\% \\ \hline \multirow{4}{*}{Enlarged LVM/BSA} & Manual reading & 37 & 13 & 14 & 13 & 0 & 23 & 37.84\% & 100.0\% & 54.00\% \\ \cline{2-10}  & Manual segmentation & 37 & 13 & 21 & 11 & 2 & 16 & 56.76\% & 84.62\% & 64.00\% \\ \cline{1-1} \cline{2-10}  & Automatic segmentation & 37 & 13 & 23 & 10 & 3 & 14 & 62.16\% & 76.92\% & 66.00\% \\ \hline \end{tabular}
\end{table} 
Table 1: Positive values, negative values, sensitivity, and specificity of different methods of cardiothoracic ratio measurements according to various definitions of cardiomegaly. Figure 2: Bland–[PERSON] plots of deep learning models based on manual (**A**) and automatic (**B**) segmentation compared to manual reading measurements. Using manual reading measurements, a tendency for more false negative results was observed, especially when indexed or non-indexed LVM were used as criteria for cardiovascular (Table 1). On the other hand, with calculations based on segmentations, slightly more false positive results were noted when elevated indexed or non-indexed LVEDV were used as a cardiomegaly definition (Table 1). However, statistical significance was only noted when elevated non-indexed LVEDV was used as the cardiomegaly definition (13 vs. 2, \(\chi^{2}(1)\) = 4.317, \(p\) = 0.04, difference: 11% [95%CI: 0.17-23.12%]), while for other criteria differences, they were not statistically significant. The receiver operating characteristic analyses showed that both the CTR measurements based on manual and automatic segmentations, and manual reading reports were good predictors for cardiomegaly diagnosed in CMR (Table 2). There was only a difference between the CTR measurements based on automatic segmentation when enlarged LVM and elevated LVEDV were used for the diagnosis of cardiomegaly (AUC = 0.659 vs. 0.864, \(p\) = 0.04, respectively).