Size-specific dose estimation for chest CT examination in pediatric patients with mycoplasma pneumoniae pneumonia
10.3969/j.issn.1002-1671.2024.10.007
- VernacularTitle:体型特异性剂量估算在儿童肺炎支原体肺炎胸部CT中的应用
- Author:
Hengxin FAN
1
;
Chunhai LUO
;
Qi PAN
;
Jiayi DU
;
Haijing QIU
Author Information
1. 西安医学院第二附属医院影像科,陕西 西安 710038
- Keywords:
size-specific dose estimation;
mycoplasma pneumoniae pneumonia;
computed tomography;
radiation dose
- From:
Journal of Practical Radiology
2024;40(10):1606-1610
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the radiation dose in low-dose chest CT examination of pediatric patients with mycoplasma pneumoniae pneumonia(MPP)by using size-specific dose estimation(SSDE).Methods A total of 95 patients who were scanned with low-dose chest CT were prospectively selected,65 patients with weight ≤50 kg,using 80 kV and DoseRight Z-DOM(30-50 mAs);30 patients with weight＞50 kg,using 100 kV and DoseRight Z-DOM(50-100 mAs).A total of 65 patients who were scanned with conventional chest CT were retrospectively collected,40 patients with weight ≤50 kg,25 patients with weight＞50 kg,using 120 kV,DoseRight Z-DOM(50-100 mAs)and fixed mAs.Image noise,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were used to objectively evaluate image quality.The subjective evaluation of image quality was performed by two radiologists using a 5-score system and a double-blind method.The volume CT dose index(CTDIvol)and dose length product(DLP)were collected,the SSDE and effective dose(ED)were measured,respectively.Results Compared with conventional scan,CTDIvol,DLP,SSDE,and ED values of 80 kV scan was decreased by 81.3％,80.3％,81.5％,and 82.4％,respectively,with a statistical difference(Z=-8.433,-8.137,-8.146,-8.142,P＜0.05).There were statistically significant differences in image noise,SNR,and CNR between 80 kV scan and conventional scan in patients with weight ≤50 kg(Z=-6.762,-5.075,-3.430,P＜0.05).In 100 kV scan,CTDIvol,DLP,SSDE,and ED values was decreased by 75.7％,76.3％,75.3％,and 75.3％,respectively,with a statistical difference(Z=-6.301,-6.173,-6.347,-6.308,P＜0.05).There were statistically significant differences in image noise and SNR between 100 kV scan and conventional scan in patients with weight＞50 kg(Z=-5.367,-4.650,P＜0.05).The subjective evaluation scores of the two groups images were all greater than 3 points,all images could be used for clinical diagnosis.SSDE was 45.3％and 29.9％higher than CTDIvol for 80 kV and 100 kV scans,respectively,SSDE was 45.7％and 28.8％higher than CTDIvol for conventional scans with weight ≤50 kg and weight＞50 kg,respectively.Conclusion Low kV combined with DoseRight Z-DOM effectively reduces radiation dose to pediatric patients with MPP;SSDE more accurately assesses radiation dose than CTDIvol in children.
