## 4 Discussion
### Patient Dose  
In Table 5, the ESAK values obtained in this study for the standard-sized patient equivalent phantom were compared with those reported in the literature. For FP fluoroscopy, our results were slightly higher than those presented by [PERSON] et al. [2], but are lower than those presented by [PERSON] et al. [22]. It is important to note that both of these studies used a standard patient equivalent phantom thickness of 20 cm, whereas, in the present study, we used a maximum patient equivalent of 24 cm and 28 cm. In general, our results are comparable to those reported in the literature and are far lower than those reported for image intensifier-based fluoroscopy. In agreement with the current findings, [PERSON] et al. [23] reported that patient doses could be reduced by a factor of four when using FPDs with no significant difference in image quality. These results advocate the need for revised tolerance levels. The results of ESAK and the image-receptor input dose rates shown in Table 6 are well within the recommended specifications.  
Regarding image-receptor input dose rates, the manufacturer recommends that the detector dose rate should be less than 1.0 mGy s\({}^{-1}\) and should never exceed 2.0 mGy s\({}^{-1}\)[10]. Thus, the current results fell within the stated recommendations. Incident air kerma to the image receptor is essential to protect the detector surface from excessive radiation exposure that might degrade its performance.  
Table 6 shows the results of radiation protection and safety measurements. Scatter radiation-absorbed dose levels ranged from 4.0 to 4.7 uGy min\({}^{-1}\), which were well within  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Minimum SID** & **Scatter Radiation at 1 m** & \multicolumn{2}{c}{**Ambient Dose Rates**} & **Warning Signs** \\ \cline{1-1} Tolerance Ref. [10] & 45 cm & 20 uGymin\({}^{-1}\) & 88 (uGy/wk) & 18 (uGy/wk) & Availability \\ \hline \multirow{3}{*}{Frontal Lateral} & \multirow{3}{*}{58} & Unit I & \multirow{3}{*}{\(<\)10} & \multirow{3}{*}{\(<\)10} & \multirow{3}{*}{Available} \\  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \cline{1-1}  & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 6: Radiation protection and safety measurements.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Phantom** & **ESAK (mGy/min)** & **IR Input (μGy/s)** & \multicolumn{2}{c}{**Digital Acquisition**} & \multirow{2}{*}{**Detector**} \\ \hline
\begin{tabular}{c} [PERSON], et al. * \\ (This Study) \\ \end{tabular} & 5 mm Al + 5 mm Cu & 8.0–9.0 & 0.2–0.4 & 0.1 & FP \\ \multirow{3}{*}{[PERSON], et al. (2008)} & 18 cm PMMA + & 10.3–12.0 & – & – & FP \\  & 2.5 mm Al & & & & \\ \cline{1-1}  & 20 cm water & 4.6 & 0.6 & 2.6 & FP \\ \multirow{3}{*}{[PERSON], et al. (2009)} & 20 cm water & 16.6 \(\pm\) 7.9 & – & 0.20 \(\pm\) 0.10 & FP \\ \cline{1-1}  & 20 cm water & 17.8 & – & 0.20 \(\pm\) 0.10 & II \\ \hline \hline \end{tabular}  
* Note: 5 mm Al + 5 mm Cu used in this study is equivalent to 24 cm PMMA phantom.  
\end{table}
Table 5: Comparison of ESAK values obtained in this study for standard sized patient equivalent phantom with those reported in the literature.  
the recommended tolerance levels. Similarly, ambient dose levels in the controlled and supervised areas were below the recommended weekly dose rates.