The influence of spectral CT monochromatic imaging technique on image quality and liver volume measurement in CT portal venography
10.3969/j.issn.1002-1671.2024.09.032
- VernacularTitle:能谱CT单能量成像技术对CT门静脉成像图像质量和肝脏体积测量的影响
- Author:
Yong FAN
1
;
Yijun LIU
;
Beibei LI
;
Shigeng WANG
;
Wei WEI
;
Xiaoyu TONG
;
Zhiming MA
;
Anliang CHEN
;
Yujing ZHOU
Author Information
1. 大连医科大学附属第一医院放射科,辽宁 大连 116011
- Keywords:
portal vein;
computed tomography;
spectral imaging;
monochromatic imaging;
image quality;
liver
- From:
Journal of Practical Radiology
2024;40(9):1536-1540
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the influence of spectral CT monochromatic imaging technique on image quality and liver vol-ume measurement in computed tomography portal venography(CTPV).Methods A total of 120 patients who underwent contrast-enhanced abdominal CT examination were prospectively selected and randomly divided into group A and group B.The group A(n=60)was scanned with conventional parameters such as 120 kVp,Smart mA mode,and image reconstruction of 60％adaptive statistical iterative reconstruction-Veo(ASIR-V);while the group B(n=60)was with instantaneous switching 80/140 kVp,gemstone spectral imaging(GSI)Assist mode,and image reconstruction of 60％ASIR-V.In group B,six subgroups of images from 75 to 50 keV(with 5 keV interval)were recorded as subgroups B1 to B6.On the axial images,the CT values and standard deviation(SD)values of por-tal vein,liver and erector spinae were measured,and then the contrast-to-noise ratio(CNR)of portal vein and liver were calculated.The Liver Segmentation software was used to segment the liver in groups A and B,the liver volumes by automatic segmentation and manual segmentation(golden standard)were recorded,and then the volume difference rate was calculated.The overall image quality and automatic liver segmentation results were evaluated by two radiologists using a 5-point scale.Results In terms of overall image quality,subgroup B6 achieved the highest score and was superior to group A(P＜0.001).In terms of liver segmentation,subgroup B3 had the highest score and was superior to group A(P＜0.001).With the decrease of keV,the CT values,SD values and CNR of portal vein and liver in group B were gradually increased(P＜0.05),in which subgroup B6 was higher than that in group A(P＜0.001).The volume difference rate initially decreased and then increased with the decrease of keV.Except for subgroups B2 and B3,the differences were statistically significant between other subgroups and group A(P＜O.001),and the subgroup B3 had the lowest volume difference rate.Conclusion Spectral CT monochromatic ima-ging technique has an influence on CTPV image quality and liver volume measurement.The 50 keV images are the best for displaying portal vein,and the automatic liver segmentation volume of 65 keV images is closest to the real liver volume.
