Impact of dose modulation intensity on CT radiation dose and image noise in adults
10.13929/j.issn.1003-3289.2020.08.026
- VernacularTitle: 剂量调制强度对成人CT辐射剂量及图像噪声的影响
- Author:
Ning LI
1
Author Information
1. Department of Radiology, Hubei Cancer Hospital
- Publication Type:Journal Article
- Keywords:
Adult;
Quality control;
Tomography, X-ray computed
- From:
Chinese Journal of Medical Imaging Technology
2020;36(8):1230-1233
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the impact of dose modulation intensity on CT radiation dose and image noise in adults. Methods: The head, chest and abdomen of phantom were scanned with fixed mAs and 5 modulation intensities (Very Weak, Weak, Average, Strong and Very Strong) based on CARE Dose4D technology. The corresponding volume CT dose indexes (CTDIvol) were recorded, and variations were calculated. The standard deviation value (SD) of images in each layer of each position were measured and taken as the noise level. CTDIvol and changes in images of fixed mAs group and 5 modulation intensity groups were analyzed, and image noise of 6 groups were compared. Results: With the increase of modulation intensity, CTDIvol of head and abdomen decreased gradually, and the corresponding change amount of CTDIvol increased. CTDIvol of chest gradually increased, but the corresponding change amount of CTDIvol decreased. There were statistical differences of SD values of head or abdomen images under different modulation intensities (F=9.73, 45.78, both P<0.01), while SD values of chest images were not statistically different (H=4.60, P=0.47). Conclusion: With the increase of modulation intensity, the radiation dose of head and abdomen of phantom decreased gradually, and image noise decreased, while the radiation dose of chest increased, but image noise had no significant change.
