CAJ | 학술논문

目的探讨能谱CT单能量图像对提高肝静脉成像质量的应用价值.方法 30例患者行上腹部能谱CT增强扫描,获得门静脉期1.25 mm层厚的质量控制(QC)图像和肝静脉最佳对比噪声比(CNR)单能图像,并行肝静脉VR和MIP重组.测量2组图像中肝静脉和肝实质的CT值及其差值、噪声及CNR,并由2名分别具有15年和10年腹部放射诊断经验的医师在盲法下对2组重建图像进行主观图像质量评分,2组间比较采用配对t检验.2名医师对重建图像质量一致性评估采用Kappa检验.结果门静脉期肝静脉最佳CNR单能图像能量水平集中在50 keV左右.在最佳CNR单能图像和QC图像上,肝静脉和肝实质的CT值及其差值、噪声及对比噪声比(CNR)分别为(329±47) HU、(178±33) HU、(151±33) HU、17.33±4.18、9.13 ±2.65和(149±18)HU、(107±14) HU、(43±11)HU、12.55±3.02、3.53+1.03;图像质量评分分别为(4.2±0.6)分和(3.1±0.8)分；差异均有统计学意义(t值分别为24.79、13.95、18.85、9.07、13.25、12.04,P值均＜0.01).2名医师对最佳CNR单能重建图像质量评价的一致性(Kappa值为0.81)高于QC重建图像(Kappa值为0.69).结论能谱CT单能量图像能显著提高肝静脉成像的图像质量.
목적 탐토능보CT단능량도상대제고간정맥성상질량적응용개치.방법 30례환자행상복부능보CT증강소묘,획득문정맥기1.25 mm층후적질량공제(QC)도상화간정맥최가대비조성비(CNR)단능도상,병행간정맥VR화MIP중조.측량2조도상중간정맥화간실질적CT치급기차치、조성급CNR,병유2명분별구유15년화10년복부방사진단경험적의사재맹법하대2조중건도상진행주관도상질량평분,2조간비교채용배대t검험.2명의사대중건도상질량일치성평고채용Kappa검험.결과 문정맥기간정맥최가CNR단능도상능량수평집중재50 keV좌우.재최가CNR단능도상화QC도상상,간정맥화간실질적CT치급기차치、조성급대비조성비(CNR)분별위(329±47) HU、(178±33) HU、(151±33) HU、17.33±4.18、9.13 ±2.65화(149±18)HU、(107±14) HU、(43±11)HU、12.55±3.02、3.53+1.03;도상질량평분분별위(4.2±0.6)분화(3.1±0.8)분；차이균유통계학의의(t치분별위24.79、13.95、18.85、9.07、13.25、12.04,P치균＜0.01).2명의사대최가CNR단능중건도상질량평개적일치성(Kappa치위0.81)고우QC중건도상(Kappa치위0.69).결론 능보CT단능량도상능현저제고간정맥성상적도상질량.
Objective To investigate the effect of spectral CT monochromatic images for improving imaging quality in hepatic venography.Methods Thirty patients underwent spectral CT examination on a GE Discovery CT 750 HD scanner.During portal phase,1.25 mm slice thickness polychromatic images and optimal monochromatic images were obtained,and volume rendering and maximum intensity projection were created to show the hepatic veins respectively.The overall imaging quality was evaluated on a five-point scale by two radiologists.Inter-observer agreement in subjective image quality grading was assessed by Kappa statistics.Paired-sample t test were used to compare hepatic vein attenuation,hepatic parenchyma attenuation,CT value difference between the hepatic vein and the liver parenchyma,image noise,vein-to-liver contrast-to-noise ratio (CNR),the image quality score of hepatic venography between the two image data sets.Results The monochromatic images at 50 keV were found to demonstrate the best CNR for hepatic vein.The hepatic vein attenuation[(329 ± 47) HU],hepatic parenchyma attenuation [(178 ± 33) HU],CT value difference between the hepatic vein and the liver parenchyma [(151 ± 33) HU],image noise (17.33 ±4.18),CNR(9.13 ±2.65),the image quality score(4.2 ±0.6) of optimal monochromatic images were significantly higher than those of polychromatic images[(149 ± 18) HU],[(107 ± 14) HU],[(43 ±11) HU],12.55 ± 3.02,3.53 ± 1.03,3.1 ± 0.8 (t values were 24.79,13.95,18.85,9.07,13.25 and 12.04,respectively,P ＜ 0.01).In the comparison of image quality,Kappa value was 0.81 with optimal monochromatic images and 0.69 with polychromatic images.Conclusion Monochromatic images of spectral CT could improve CNR for displaying hepatic vein and improve the image quality compared to the conventional polychromatic images.