## 3 Results and Discussion  
The effective doses (E\({}_{\text{d}}\)) were calculated from CT retrospective data examinations using tissue weighting factors and organ dose estimates from ICRP (60, 103) and CT-Expo v2.6 compared with DLP-based effective dose estimates (Table 3). The effective dose (E\({}_{\text{DLP}}\)) underestimated the E\({}_{\text{d}}\) for tube voltage (120 kVp) in CT examinations in a manner comparable to the organ-based estimation of E\({}_{60}\), and the dissimilarities in terms of percentages were \(-59\%\) (head), \(18.1\%\) (chest), and \(-20\%\) (abdomen). The calculated organ-based effective dose E\({}_{103}\) underestimates E\({}_{\text{DLP}}\) only for the head exams, and the largest difference (E\({}_{\text{DLP}}-\)E\({}_{103}\)) was \(-5.17\) mSv, \(-79\%\). The E\({}_{\text{DLP}}\) underestimated all the examinations of organ-based calculations relative to the CT-Expo Monte Carlo Simulations of E\({}_{\text{s60}}\), except for the chest exam, and the percentages differences \(\left(\frac{\text{E\_{K9D}}-\text{E\_{K90}}}{\text{E\_{K90}}}\%\right)\) were \(-54\%\) and \(-6\%\) for the head and abdomen, respectively. The chest exam was approximately the same, with an increase of \(0.1\) mSv, a comparative increase of \(2\%\). All other calculations of E\({}_{\text{DLP}}\) using the coefficient K values for ICRP\({}_{103}\) (Table 3) show the energy independently, and the largest relative differences (\(\frac{\text{E\_{DLP}}-\text{E\_{K90}}}{\text{E\_{K90}}}\%\)) for the abdomen (3.76 mSv, 49\(\%\)). Table 4 shows the results of the estimated effective dose based on the organ dose of ICRP \(60,103\) compared with Monte Carlo simulation CT-Expo-v2.6. The results in Table 4 show the differences between the maximum and minimum (range, scope E\({}^{\text{b}}\)) estimated effective doses for E\({}_{\text{s60}}\), E\({}_{\text{s103}}\), E\({}_{\text{60}}\), and E\({}_{\text{103}}\), the average was \(0.56\) mSv (head), \(-1.88\) mSv (chest), and \(-2.26\) mSv (abdomen) of the effective dose E\({}_{\text{s60}}\)  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{ \begin{tabular}{c} **Regional** \\ **Anatomy** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Tube** \\ **Voltages** \\ **(kVp)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **CTDL** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **DLP** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{\ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **E\({}_{\text{s60}}\)** \\ **(mSv)** \\ \end{tabular}  } & \multirow{2}{*}{\values. Comparing the four effective doses, E\({}_{60}\) was the largest (12.1 mSv (abdomen)) and the smallest (1.1 mSv (head)). Considering the recommended ICRP 103 rather than ICRP 60 and using tissue weighting factors to calculate the effective dose, the abdomen and chest effective doses increased by 1.4 mSv because of the increase in the tissue weighting factors. Comparing the calculated and simulated effective dose (E\({}_{\text{DLP}}-\)E\({}_{60}\)), for the CT head, the effective dose decreased by 1.5 mSv, 54%. These changes prove that the effective dose is dependent on the parameters used to calculate--whether in the simulation or the derived coefficient values. As a result, the value of the effective dose Ed varies depending on the tissue weighting factors used.