# New Approaches to AI Methods for Screening Cardiomegaly on Chest Radiographs
## 5 Conclusions  
The use of AI for the segmentation of the lungs and heart may optimize the screening process for cardiomegaly on chest radiographs with CTR and TCD measurements. The proper segmentation of the lungs and heart may be difficult to perform in some cases, especially in patients with various cardiovascular and pulmonological diseases. Therefore, in the cases of an obscured heart border or suspicion of LVH, supervision by a radiologist is recommended. Since previous research has primarily compared automatic segmentation with radiologist interpretations of CXRs, future studies should focus on improving the accuracy of AI algorithms (which ranged from 62.0 to 74.0% in our study for CTR, and from 64.0 to 72.0% for TCD) by evaluating them against the gold standard for the assessment of cardiac size, which is based on CMR imaging. Additionally, further investigation is needed to compare the utility of AI-derived CTR and TCD measurements in screening for cardiomegaly on chest radiographs. Study conception and design: P.S.M., Z.T. and T.J.P. Acquisition of data: P.S.M. Analysis and interpretation of data: P.S.M., Z.T., I.K. and J.D.J. Drafting the first version of the manuscript: P.S.M. Critical revision and editing of the manuscript: all authors. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of Jagiellonian University for studies involving humans (Date 13 May 2024/No 118.0043.1.175.2024). Not applicable. The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author. The authors declare no conflicts of interest. Appendix AFigure 16: Example of chest radiograph showing a weak correlation of thautomatic measurements with the references. (**A**)—original chest radiograph; (**B**)—CTR estimation from the manual segmentation; (**C**)—CTR estimation from the automatic segmentation. Abbreviations: CTR—cardiothoracic ratio. Figure 14: Correlations of transverse cardiac diameter between the direct manual measurements made by radiologists, measurements from the manual segmentation, and from the automatic segmentation. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Case Number—Testing Set** & **Manual Reading** & **Manual Segmentations** & **Automatic Segmentations** \\ \hline
1 & 0.42 & 0.43 & 0.42 \\ \hline
2 & 0.44 & 0.41 & 0.41 \\ \hline
3 & 0.42 & 0.42 & 0.54 \\ \hline
4 & 0.51 & 0.58 & 0.57 \\ \hline
5 & 0.44 & 0.50 & 0.52 \\ \hline
6 & 0.55 & 0.58 & 0.54 \\ \hline
7 & 0.57 & 0.52 & 0.52 \\ \hline
8 & 0.46 & 0.49 & 0.50 \\ \hline
9 & 0.54 & 0.57 & 0.55 \\ \hline
10 & 0.41 & 0.39 & 0.41 \\ \hline
11 & 0.48 & 0.48 & 0.48 \\ \hline
12 & 0.39 & 0.40 & 0.39 \\ \hline
13 & 0.43 & 0.52 & 0.47 \\ \hline
14 & 0.46 & 0.47 & 0.47 \\ \hline
15 & 0.46 & 0.45 & 0.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cardiothoracic ratio measurement results for manual reading, manual segmentations, and automatic segmentations. **Table A1. **_Cont._