# New Approaches to AI Methods for Screening Cardiomegaly on Chest Radiographs
## 3 Results
### Transverse Cardiac Diameter
However, when elevated LVEDV or LVEDV/BSA were used as a cardiomegaly definition, the measurements made from the segmentation models were not in agreement with the CMR diagnosis (Appendix A Table A6). Specificity for direct manual measurements reached 100%; however, sensitivity was much lower when compared to the TCD measurements made with our AI model (see Table 3). Using direct manual measurements, many more false negative results were observed, especially when indexed or non-indexed LVM was used in the criteria of cardiomegaly. In contrast, using calculations made from segmentation models, slightly more false positive results were noted, especially when elevated indexed or non-indexed LVEDV was used as a cardiomegaly definition (Table 3). However, these differences were observed only numerically and did not reach statistical significance, suggesting that a larger sample size may be needed to detect significant differences. The receiver operating characteristic analyses showed that both the TCD measurements based on manual and automatic segmentations, and manually read reports were good predictors for cardiomegaly diagnosed in CMR (Table 4). There were only differences between the TCD measurements based on automatic segmentation when enlarged LVM and elevated LVEDV or LVM/BSA and LVEDV/BSA were used for the diagnosis of cardiomegaly (AUC = 0.731 vs. AUC = 0.916, \(p\) = 0.03; AUC = 0.734 vs. AUC = 928, \(p\) = 0.02, respectively). \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline
**Cardiomegaly Definition** & **Method of** & **P** & **N** & **TP** & **TN** & **FP** & **FN** & **Sensitivity** & **Specificity** & **Accuracy** \\ \cline{2-11} \multirow{4}{*}{Both elevated LVEDV and enlarged LVM} & Manual reading & 38 & 12 & 19 & 12 & 0 & 19 & 50.0\% & 100.0\% & 62.00\% \\ \cline{2-11}  & Manual segmentation & 38 & 12 & 26 & 8 & 4 & 12 & 68.42\% & 66.67\% & 68.00\% \\ \cline{2-11}  & Automatic segmentation & 38 & 12 & 27 & 8 & 4 & 11 & 71.05\% & 66.67\% & 70.00\% \\ \cline{2-11}  & Manual reading & 37 & 13 & 19 & 13 & 0 & 18 & 51.35\% & 100\% & 64.00\% \\ \cline{2-11}  & Manual segmentation & 37 & 13 & 25 & 8 & 5 & 12 & 67.57\% & 61.54\% & 66.00\% \\ \cline{2-11}  & Automatic segmentation & 37 & 13 & 25 & 7 & 6 & 12 & 67.57\% & 53.85\% & 64.00\% \\ \hline \multirow{4}{*}{Elevated LVEDV} & Manual reading & 16 & 34 & 14 & 29 & 5 & 2 & 87.5\% & 85.29\% & 86.00\% \\ \cline{2-11}  & Manual segmentation & 16 & 34 & 15 & 19 & 15 & 1 & 93.75\% & 55.88\% & 68.00\% \\ \cline{2-11}  & Automatic segmentation & 16 & 34 & 15 & 18 & 16 & 1 & 93.75\% & 52.94\% & 66.00\% \\ \cline{2-11}  & Manual reading & 37 & 13 & 19 & 13 & 0 & 18 & 51.35\% & 100\% & 64.00\% \\ \cline{2-11}  & Manual segmentation & 37 & 13 & 25 & 8 & 5 & 12 & 67.57\% & 61.54\% & 66.00\% \\ \cline{2-11}  & Automatic segmentation & 37 & 13 & 26 & 8 & 5 & 11 & 70.27\% & 61.54\% & 68.00\% \\ \hline \multirow{4}{*}{Elevated LVEDV/BSA} & Manual reading & 17 & 33 & 15 & 29 & 4 & 2 & 88.24\% & 87.88\% & 88.00\% \\ \cline{2-11}  & Manual segmentation & 17 & 33 & 16 & 19 & 14 & 1 & 94.11\% & 57.56\% & 70.00\% \\ \cline{2-11}  & Automatic segmentation & 17 & 33 & 17 & 19 & 14 & 0 & 100\% & 57.56\% & 72.00\% \\ \cline{2-11}  & Manual reading & 37 & 13 & 19 & 13 & 0 & 18 & 51.35\% & 100.0\% & 64.00\% \\ \cline{2-11}  & Manual segmentation & 37 & 13 & 25 & 8 & 5 & 12 & 67.57\% & 61.54\% & 66.00\% \\ \cline{2-11}  & Automatic segmentation & 37 & 13 & 25 & 7 & 6 & 12 & 67.57\% & 53.85\% & 64.00\% \\ \hline \end{tabular} Abbreviations: BSA—body surface area; CMR—cardiac magnetic resonance; LVEDV—left ventricle end–diastolic volume; LVM—left ventricular mass; N—all negative cases (TN + FP); P—all positive cases (TP + FN); TN—true negative; TP—true positive.  
\end{table} 
Table 3: Positive and negative values, sensitivity, and specificity of different methods of transverse cardiac diameter measurements according to various definitions of cardiomegaly.