Improving image quality in portal venography with dual-layer detector spectral CT imaging
WANG Shi-wei1, LI Jin-feng2, ZOU Ying1, LI Tao2, LUO Chun-cai2, HUANG Zi-li2, LI Xue-ping2
1. Department of Radiology, PLA General Hospital, Hainan Hospital, Sanya Hainan 572013, China;
2. Department of Radiology, First Medical Center, PLA General Hospital, Beijing 100853, China
Abstract：Objective: To investigate the effect of optimal monochromatic energy image on the image quality of portal venography with dual-layer detector spectral CT. Methods: Thirty-nine patients suspected of abdominal disease underwent contrast-enhanced CT examination using a single-source, dual-detector spectral CT. The portal vein phase scan was performed 60 seconds after 60 mL iopamidol(320 mg/mL) injection at the speed of 3 mL/s. The raw images were reconstructed to obtain polychromatic 120 kVp images and spectral based images. The 40, 50, 60, 70 keV monochromatic images were gotten. Image noise, signal-to-noise ratio(SNR) of portal vein and contrast-to-noise ratio(CNR) of portal vein relative to the erector spine muscle from polychromatic 120 kVp images and 40, 50, 60, 70 keV monochromatic images were measured. Anova test was used to compare the noise, SNR and CNR among 5 groups. An optimal monochromatic image set was chosen for obtaining the best SNR and CNR for portal vein. Image quality was also evaluated on a five-point scale by two radiologists. Results: The difference of noise, SNR, CNR of portal vein among five groups were statistically significant(P<0.05). The noise at 40 keV group was significantly lower than that of polychromatic 120 kVp group. The SNR and CNR of 40 keV group was significantly higher than that of other groups(P<0.05), much higher than that of polychromatic 120 kVp group. The image quality score of 40 keV optimal monochromatic image was superior to that of polychromatic images. The agreement of image quality grading between two doctors was good. Conclusion: 40 keV is the optimal monochromatic image for displaying portal vein using dual-layer detector spectral CT.
王世伟1，李金锋2，邹 颖1，李 涛2，罗春材2，黄自立2，李雪萍2. 双层探测器能谱CT单能级成像对门静脉成像质量的影响[J]. 中国临床医学影像杂志, 2020, 31(6): 425-428.
WANG Shi-wei1, LI Jin-feng2, ZOU Ying1, LI Tao2, LUO Chun-cai2, HUANG Zi-li2, LI Xue-ping2. Improving image quality in portal venography with dual-layer detector spectral CT imaging. JOURNAL OF CHINA MEDICAL IMAGING, 2020, 31(6): 425-428.
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