The effect of the out-of-plane shield on the tube current and radiation dose of CT examination
10.3969/j.issn.1002-1671.2025.04.029
- VernacularTitle:面外防护对CT检查管电流及辐射剂量的影响
- Author:
Juan ZHOU
1
;
Yuxin HAN
;
Peng QU
;
Rong LÜ
Author Information
1. 天津市第三中心医院医务处,天津 300170
- Publication Type:Journal Article
- Keywords:
computed tomography;
radiation dose;
radiation protection
- From:
Journal of Practical Radiology
2025;41(4):669-672
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the effect of different ways of out-of-plane shield on the tube current and cumulative radiation dose of CT scan.Methods The CT water membrane was scanned using Philips 128 row iCT scanner in different scanning methods:the 1-3 times,without the out-of-plane shield,the total length of localizer was 150 mm,270 mm,and 390 mm,respectively;the fourth time,the out-of-plane shield was used but was not present in the localizer;from the 5th to 7th pass,with out-of-plane shield and develop it in the localizer,with out-of-plane shield development lengths of 60 mm,180 mm,and 300 mm,respectively,and the out-of-plane shield was not within the formal scanning range.The tube current and cumulative radiation dose of various scanning methods were compared and a line graph of the tube current for scanning each layer was figured.Results(1)There was no statistically significant difference in tube current when there was no out-of-plane shield but the length of the localizer was different(P＞0.05).(2)When the pitch was 0.8,1.0,and 1.15 respectively,with out-of-plane shield but no shield object in the localizer,the scanning tube current was lower than that without shield scanning(P＜0.05).(3)When scanning with three different lengths of out-of-plane shield(60 mm,180 mm,300 mm)in the localizer,regardless of the pitch,the tube current was greater than that of unshield scanning(P＜0.05).(4)When there was a shield in the localizer,the closer to the shield,the higher the tube current in the formal scan.(5)The cumulative dose of scans with out-of-plane shield but without the presence of shield in the localizer was smaller than that of unshield scanning.However,with shield and the presence of shield scanning in the localizer,the cumulative radiation dose was greater than that of unshield scanning.Conclusion The presence of out-of-plane shield in the localizer may increase the tube current and radiation dose for formal scanning,and the closer to the shield,the more significant the increase in tube current.
