RESUMO
Objective: To explore the diagnostic dosage of enhanced computed tomography (CT) of chest and its influence factor through analyzed the data of radiation dosage of enhanced CT of chest. Methods: The scanning data of 297 patients who were implemented scan on 4 different CT devices were compared by using retrospective analysis. And they were divided into A, B, C and D group as different device. The differences of scan sequence among different devices were compared, and volume computed tomography dose index(CTDIvol), dose length product(DLP) and effective dose(ED) were recorded and analyzed. Results: The CTDIvols of 4 groups were (12.18±4.13), (8.86±3.18), (10.70±5.18) and 13.59mGy, respectively, and the differences among them were significant (F=38.58, P<0.05). And the DLPs of the 4 groups were (433.54±145.18), (311.62±112.75), (368.04±181.22) and (475.75±34.25)mGy·cm, and the differences among these groups were significant (F=36.33, P<0.05). Besides, the EDs of the 4 groups were (6.07±2.03), (4.36±1.58), (5.15±2.54) and (6.66±0.48) mSv, and the differences among these groups also were significant (F=36.32, P<0.05). And the comparison between any two means of radiation dosage were significant. Conclusion: The exposure dose of patients who received enhanced CT of chest was correlative with the type of CT device and acquisition parameters. And the effective dosage of patients under automatic tube current module was lower than that of fixed tube current module. And the modulation technique of current of ray tube as angle can efficiently reduce the effective dose. In clinical practice, patients' radiation dosage can be reduced by optimizing the scanning parameters.