Abstract
Objective
To explore the influence of patient’s individual factors on the radiation dose in chest computed tomography (CT) scan.
Methods
Based on the clinical chest CT scan scheme and the scanning conditions were unified, Basic data of 103 patients who underwent chest CT scanning, including gender, age, height, weight and underlying diseases, were prospectively collected, and the dose length product (DLP) of each patient was recorded, Multivariate regression analysis was made on the obtained data.
Results
Under the same scanning parameters, image quality had no significant effect on chest CT radiation dose (P = 0.404 > 0.05); among the 103 cases, there were 20 kinds of basic diseases, only calcified lesion has a significant effect on chest CT radiation dose (P = 0.009 < 0.05), the other had no significant effects (P > 0.05); the major effect individual factors of radiation dose in CT scan were: gender (P = 0.000003 < 0.05), age (P = 0.016 < 0.05), height (P = 0.000021 < 0.05), weight (P = 4.30E-16 < 0.05). Age (P = 8.08E-8 < 0.05) and weight (P = 5.52E-21 < 0.05) were the only decisive factors in multiple regression analysis, while other influencing factors were not decisive (P > 0.05). The regression model was as follows: DLP=-39.45 + 2.19*age + 5.54*weight, the coefficient of multiple correlation R being 0.786, F(2,100) = 77.128, P < 0.01. Mean that gradually increase in age was related with 2.19 mGy∙cm increase in the DLP value, 1 kg increase in weight was associated with 5.54 mGy∙cm increase in the DLP value.
Conclusion
For chest CT, age and weight are the major impact individual factors of radiation dose. This model has shown obvious clinical significance and can provide solid theoretical basis for clinical application in reducing the radiation dose in chest CT.
CT radiation dose reduction: can we do harm by doing good?