放射学实践
放射學實踐
방사학실천
RADIOLOGIC PRACTICE
2015年
4期
360-363
,共4页
张龙敏%刘爱连%刘义军%佟梓滨%浦仁旺%刘晓峰
張龍敏%劉愛連%劉義軍%佟梓濱%浦仁旺%劉曉峰
장룡민%류애련%류의군%동재빈%포인왕%류효봉
门静脉%体层摄影术,X线计算机%能谱成像%单能量图像%图像质量
門靜脈%體層攝影術,X線計算機%能譜成像%單能量圖像%圖像質量
문정맥%체층섭영술,X선계산궤%능보성상%단능량도상%도상질량
Portal vein%Tomography,X-ray computed%Spectral imaging%Monochromatic images%Image quality
目的：探讨宝石CT能谱成像最佳对比噪声比（CNR）单能量图像对提高低浓度对比剂门静脉成像质量的应用价值。方法：将符合纳入标准的136例患者随机分为2组，A 组采用高浓度对比剂（350mg I／100mL）和常规 CT 扫描（1．25mm层厚）、B组采用低浓度对比剂（270mg I／100mL）和宝石CT能谱成像（GSI）。由两位放射科医师采用双盲法分别测量两组图像上门静脉左支、右支和肝实质的CT值及图像噪声，对两位观察者的测量结果采用组内一致性系数（ICC ）进行分析；采用较高年资观察者的测量结果，计算门静脉的对比噪声比（CNR），并对两组的测量结果及CNR 值分别行t检验；经图像后处理，分别获得两组图像的VR和 MIP重组图像并进行图像质量的主观评分，对2位医师的图像质量评分采用Kappa检验，并采用较高年资观察者的评分结果和秩和检验法对2组间的图像质量进行比较。结果：B组中门静脉最佳CNR单能量图像的能量水平集中在50KeV左右。两位观察者测量数据的一致性较好（ICC＞0．75）。A组中门静脉左支、门静脉右支和肝实质的CT值及背景噪声（SD值）分别为（178．38±27．25）、（174．78±24．66）、（116．13±17．01）和（32．78±4．72）HU，B组分别为（334．01±58．74）、（328．51±55．78）、（187．89±32．23）和（39．12±10．05）HU，这4个测量指标在两组间的差异均有统计学意义（P＜0．05）。B 组中门静脉左、右支与肝实质的 CNR（分别为4．08±1．90和3．93±1．80）均高于A组（分别为1．92±0．68和1．80±0．59），两组间差异有统计学意义（P均＜0．01）。两位医师对重组图像的主观评价结果一致性较好（A 组Kappa 值为0．900，B组Kappa 值为0．902）；两组的图像质量评分分别为3．26±0．50和3．23±0．43，差异无统计学意义（P＝0．896）。结论：能谱CT能提供多组单能量图像，且在降低对比剂浓度的前提下，GSI最佳CNR单能量图像能显著提高门静脉与肝实质的对比噪声比，很好地显示门静脉及其分支。
目的：探討寶石CT能譜成像最佳對比譟聲比（CNR）單能量圖像對提高低濃度對比劑門靜脈成像質量的應用價值。方法：將符閤納入標準的136例患者隨機分為2組，A 組採用高濃度對比劑（350mg I／100mL）和常規 CT 掃描（1．25mm層厚）、B組採用低濃度對比劑（270mg I／100mL）和寶石CT能譜成像（GSI）。由兩位放射科醫師採用雙盲法分彆測量兩組圖像上門靜脈左支、右支和肝實質的CT值及圖像譟聲，對兩位觀察者的測量結果採用組內一緻性繫數（ICC ）進行分析；採用較高年資觀察者的測量結果，計算門靜脈的對比譟聲比（CNR），併對兩組的測量結果及CNR 值分彆行t檢驗；經圖像後處理，分彆穫得兩組圖像的VR和 MIP重組圖像併進行圖像質量的主觀評分，對2位醫師的圖像質量評分採用Kappa檢驗，併採用較高年資觀察者的評分結果和秩和檢驗法對2組間的圖像質量進行比較。結果：B組中門靜脈最佳CNR單能量圖像的能量水平集中在50KeV左右。兩位觀察者測量數據的一緻性較好（ICC＞0．75）。A組中門靜脈左支、門靜脈右支和肝實質的CT值及揹景譟聲（SD值）分彆為（178．38±27．25）、（174．78±24．66）、（116．13±17．01）和（32．78±4．72）HU，B組分彆為（334．01±58．74）、（328．51±55．78）、（187．89±32．23）和（39．12±10．05）HU，這4箇測量指標在兩組間的差異均有統計學意義（P＜0．05）。B 組中門靜脈左、右支與肝實質的 CNR（分彆為4．08±1．90和3．93±1．80）均高于A組（分彆為1．92±0．68和1．80±0．59），兩組間差異有統計學意義（P均＜0．01）。兩位醫師對重組圖像的主觀評價結果一緻性較好（A 組Kappa 值為0．900，B組Kappa 值為0．902）；兩組的圖像質量評分分彆為3．26±0．50和3．23±0．43，差異無統計學意義（P＝0．896）。結論：能譜CT能提供多組單能量圖像，且在降低對比劑濃度的前提下，GSI最佳CNR單能量圖像能顯著提高門靜脈與肝實質的對比譟聲比，很好地顯示門靜脈及其分支。
목적：탐토보석CT능보성상최가대비조성비（CNR）단능량도상대제고저농도대비제문정맥성상질량적응용개치。방법：장부합납입표준적136례환자수궤분위2조，A 조채용고농도대비제（350mg I／100mL）화상규 CT 소묘（1．25mm층후）、B조채용저농도대비제（270mg I／100mL）화보석CT능보성상（GSI）。유량위방사과의사채용쌍맹법분별측량량조도상상문정맥좌지、우지화간실질적CT치급도상조성，대량위관찰자적측량결과채용조내일치성계수（ICC ）진행분석；채용교고년자관찰자적측량결과，계산문정맥적대비조성비（CNR），병대량조적측량결과급CNR 치분별행t검험；경도상후처리，분별획득량조도상적VR화 MIP중조도상병진행도상질량적주관평분，대2위의사적도상질량평분채용Kappa검험，병채용교고년자관찰자적평분결과화질화검험법대2조간적도상질량진행비교。결과：B조중문정맥최가CNR단능량도상적능량수평집중재50KeV좌우。량위관찰자측량수거적일치성교호（ICC＞0．75）。A조중문정맥좌지、문정맥우지화간실질적CT치급배경조성（SD치）분별위（178．38±27．25）、（174．78±24．66）、（116．13±17．01）화（32．78±4．72）HU，B조분별위（334．01±58．74）、（328．51±55．78）、（187．89±32．23）화（39．12±10．05）HU，저4개측량지표재량조간적차이균유통계학의의（P＜0．05）。B 조중문정맥좌、우지여간실질적 CNR（분별위4．08±1．90화3．93±1．80）균고우A조（분별위1．92±0．68화1．80±0．59），량조간차이유통계학의의（P균＜0．01）。량위의사대중조도상적주관평개결과일치성교호（A 조Kappa 치위0．900，B조Kappa 치위0．902）；량조적도상질량평분분별위3．26±0．50화3．23±0．43，차이무통계학의의（P＝0．896）。결론：능보CT능제공다조단능량도상，차재강저대비제농도적전제하，GSI최가CNR단능량도상능현저제고문정맥여간실질적대비조성비，흔호지현시문정맥급기분지。
Objective:To investigate the effect of spectral CT monochromatic images with the best contrast-to-noise ratio (CNR)for improving the imaging quality of portography using low-concentration contrast medium.Methods:Accord-ing to the inclusion criteria,136 patients were selected and randomly divided into two groups for portography:in group A, contrast medium with high concentration (350mg I/100mL)and conventional CT were used;and in group B,low-concentra-tion contrast medium (270mg I/100mL)and gemstone spectral imaging (GSI)were used.CT value of liver parenchyma, left- and right-portal vein,and image noise on portography images were measured independently and blinded by two radiolo-gists ,and the results of two observers were analyzed with intra-class correlation coefficient (ICC).The CNR of the left- and right-portal vein was calculated using the data from the senior doctor,and independent t-test were used to compare the differences of the indexes mentioned above between the two groups.Then the data were post-processed using volume ren-dering (VR)and maximum intensity projection (MIP)methods.Image quality of portography in two groups was evaluated on a five-point scale by two radiologists.The inter-observer agreement of image quality grade was analyzed by Kapppa test. Then image quality of the two groups was compared by the Wilcoxon test using the data from the senior doctor.Results:In group B,the monochromatic images at 50KeV were found to have the best CNR.The agreements of the value of the three indexes measured by the two observers were good all (ICC>0.75).The CT value of left portal vein、right portal vein and liver parenchyma,and image noise of group A were (178.38±27.25),(174.78±24.66),(116.13±17.01)and (32.78± 4.72)HU,and those of group B were (334.01±58.74),(328.51±55.78),(187.89±32.23)and (39.12±10.05)HU, there were significant differences between the two groups (P<0.05).The CNRs of left- and right portal vein to liver pa-renchyma of group A (1.92±0.68 and 1.80±0.59,respectively)were lower than those of group B (4.08±1.90 and 3.93±1.80)with statistic difference between the two groups (P<0.01).The agreement of the image quality grading be-tween the two observers was good (In group A,Kappa value= 0.900;in group B,Kappa value= 0.902).The image quality scores of group A and B were 3.26±0.50 and 3.23±0.43 respectively,there was no significant difference between the two groups (P= 0.896).Conclusion:Compared with conventional MSCT,spectral CT imaging can provide multiple sets of sin-gle-energy images and improve CNR and image quality of portography using low concentration of contrast medium.
