CAJ | 학술논문

目的：研究宝石 CT 能谱成像技术(GSI)和多种伪影去除序列(MARS)在消除金属植入物伪影方面的应用价值,并获得图像质量最佳单能量图像。方法选取本院21例含金属植入物的患者,行 GSI 扫描,获得140 kVp 的混合能量图像；并应用能谱分析软件,获得40~140 keV(以10 keV 为间距)共11组单能量图像,将其重建成单能量加 MARS 图像,由3名放射医师采用盲法对2种成像方式的图像质量行主观评价。选取每组图像中伪影最重层面及无伪影层面行感兴趣区(ROI)CT 值和噪声(SD)值的测量,并计算对比噪声比(CNR)和伪影指数(AI)。对能谱图像组和混合能量图像的 CNR 和 AI 进行配对 t 检验。结果2种成像方式的 CNR 在40~120 keV 均存在统计学意义(P <0.05),且单能量加 MARS 成像的图像在70 keV 时 CNR 最佳(CNR=8.75±3.28)；在130~140 keV 无统计学意义(P >0.05)。2种成像方式的 AI 在40~60 keV 无统计学意义(P >0.05),在70~140 keV存在明显统计学差异(P <0.05),且单能量加 MARS 图像的 AI 值在110 keV 最低(AI=26.95±9.64),120 keV 次之(AI=27.05±10.04)。结论能谱 CT 成像技术和 MARS 技术可以有效减少受检部位的金属伪影和硬化伪影,图像质量明显优于常规混合能量图像,且在70 keV 时 CNR 最佳,在110~120 keV 时去除伪影效果最优,对金属植入物术后患者的影像学诊断有重要意义。
목적：연구보석 CT 능보성상기술(GSI)화다충위영거제서렬(MARS)재소제금속식입물위영방면적응용개치,병획득도상질량최가단능량도상。방법선취본원21례함금속식입물적환자,행 GSI 소묘,획득140 kVp 적혼합능량도상；병응용능보분석연건,획득40~140 keV(이10 keV 위간거)공11조단능량도상,장기중건성단능량가 MARS 도상,유3명방사의사채용맹법대2충성상방식적도상질량행주관평개。선취매조도상중위영최중층면급무위영층면행감흥취구(ROI)CT 치화조성(SD)치적측량,병계산대비조성비(CNR)화위영지수(AI)。대능보도상조화혼합능량도상적 CNR 화 AI 진행배대 t 검험。결과2충성상방식적 CNR 재40~120 keV 균존재통계학의의(P <0.05),차단능량가 MARS 성상적도상재70 keV 시 CNR 최가(CNR=8.75±3.28)；재130~140 keV 무통계학의의(P >0.05)。2충성상방식적 AI 재40~60 keV 무통계학의의(P >0.05),재70~140 keV존재명현통계학차이(P <0.05),차단능량가 MARS 도상적 AI 치재110 keV 최저(AI=26.95±9.64),120 keV 차지(AI=27.05±10.04)。결론능보 CT 성상기술화 MARS 기술가이유효감소수검부위적금속위영화경화위영,도상질량명현우우상규혼합능량도상,차재70 keV 시 CNR 최가,재110~120 keV 시거제위영효과최우,대금속식입물술후환자적영상학진단유중요의의。
Objective To evaluate the value of gemstone spectral imaging (GSI)and multi artifact reduction system(MARs)in re-ducing metallic implants artifacts,and find the best monochromatic images.Methods Twenty-one patients with metal implants in our hospital receievd GSI examination ,MARS reconstruction and polychromatic images(140 kVp).Eleven groups of monochromatic and MARS images were obtained from 40 keV to 140 keV every interval of 10 keV by the special GSI viewer ,respetively.Subjective image quality of two methods were assessed by 3 radiologists in consensus.For every patient one group monochromatic images and blend enery images were selected two heaviest artifacts level and no artifacts level,the CT value and the standard deviations(SD)value of the region of interest(ROI)were meatured of artifacts.Contrast-to-noise ratio(CNR)and artifacts index(AI)were also caculated and were analyzed with paired-t test.Results There was significant statistical differences of CNR between energy spectral images and blend energy images in energy level of 40 to 120 keV(P <0.05),while there was no difference in energy level of 130 to 140 keV (P >0.05),and the optimal CNR was acquired at the energy level of 70 keV(CNR=8.75±3.28).The value of AI for two mehtods has no difference in energy level scope 40 to 60 keV(P >0.05),there was significant statistical differences of AI between energy spectral images and blend energy images in energy level of 70 to 140 keV(P <0.05),and the lowest of AI(AI=26.95±9.64)was ac-quired at 1 10 keV images.Conclusion The energy spectral CT possess superiority in decreasing the artifacts and will provide high image quality in the metal implants.Gemstone spectral CT has great significance for postoperative patients with metal implants in imaging diagnosis.