中华放射学杂志
中華放射學雜誌
중화방사학잡지
Chinese Journal of Radiology
2011年
3期
264-269
,共6页
胡敏霞%赵心明%宋俊峰%周纯武%赵红枫
鬍敏霞%趙心明%宋俊峰%週純武%趙紅楓
호민하%조심명%송준봉%주순무%조홍풍
腹部%辐射剂量%体层摄影术,X线计算机
腹部%輻射劑量%體層攝影術,X線計算機
복부%복사제량%체층섭영술,X선계산궤
Abdomen%Radiation dosage%Tomography,X-ray computed
目的 利用测量模型探讨64层螺旋CT腹部扫描合理的管电流值.方法 (1)模型研究:设置管电压为120 kVp,管电流分别为450、400、380、360、340、320、300、280 mA,扫描测量模型中的CTP515低对比分辨率模块,3名阅片者独立评价图像质量,获得最优管电流条件及导致图像质量发生质变的管电流区间值后应用于临床研究.(2)临床研究:选取3个月内行2次腹部CT平扫检查患者45例.首次检查均采用管电流450 mA,第2次检查采用完全随机化分组方法把受检者分为3组,每组各15例,管电流设置组l使用最优管电流,组2使用最优管电流+区间值,组3使用最优管电流-区间值,3名阅片者对肝门、胰腺、肾上极3个层面进行诊断接受率评价,对腹主动脉、门静脉、肝脏、脾脏、胆囊、胰腺、肾皮质、肾髓质进行图像主观噪声评价.图像质量比较采用秩和检验,各组间受检者个体化因素比较采用方差分析.结果 (1)腹部CT扫描最优扫描管电流为340 mA,导致图像质量发生质变的区间值为40 mA.(2)对腹主动脉、门静脉主干、肝脏、脾脏、胰腺、胆囊、肾皮质、肾髓质及肝门、胰腺、肾上极3个层面的图像质量评分,组1内(340 mA和450 mA)和组2内(380 mA和450 mA)比较差异均无统计学意义(P值均＞0.05);组3内300 mA的评分为(2.92±0.62)、(2.92±0.62)、(2.64 ±0.84)、(2.72±0.82)、(2.63±0.71)、(2.51±0.84)、(3.04±0.72)、(3.04±0.72)、(2.63±0.71)、(2.52±0.73)、(2.93±0.81)分,450 mA的评分为(3.93±0.72)、(3.94±0.72)、(3.41±0.64)、(3.43±0.61)、(3.62±0.93)、(3.63 ±0.71)、(3.93±0.81)、(3.93±0.81)、(3.43±0.61)、(3.52±0.92)、(3.84±0.82)分,二者比较差异均有统计学意义(Z=-2.449～-2.236,P值均＜0.05).结论 降低管电流以降低腹部CT扫描辐射剂量的方案是可行和有效的,腹部CT扫描合理的管电流条件为340 mA.
目的 利用測量模型探討64層螺鏇CT腹部掃描閤理的管電流值.方法 (1)模型研究:設置管電壓為120 kVp,管電流分彆為450、400、380、360、340、320、300、280 mA,掃描測量模型中的CTP515低對比分辨率模塊,3名閱片者獨立評價圖像質量,穫得最優管電流條件及導緻圖像質量髮生質變的管電流區間值後應用于臨床研究.(2)臨床研究:選取3箇月內行2次腹部CT平掃檢查患者45例.首次檢查均採用管電流450 mA,第2次檢查採用完全隨機化分組方法把受檢者分為3組,每組各15例,管電流設置組l使用最優管電流,組2使用最優管電流+區間值,組3使用最優管電流-區間值,3名閱片者對肝門、胰腺、腎上極3箇層麵進行診斷接受率評價,對腹主動脈、門靜脈、肝髒、脾髒、膽囊、胰腺、腎皮質、腎髓質進行圖像主觀譟聲評價.圖像質量比較採用秩和檢驗,各組間受檢者箇體化因素比較採用方差分析.結果 (1)腹部CT掃描最優掃描管電流為340 mA,導緻圖像質量髮生質變的區間值為40 mA.(2)對腹主動脈、門靜脈主榦、肝髒、脾髒、胰腺、膽囊、腎皮質、腎髓質及肝門、胰腺、腎上極3箇層麵的圖像質量評分,組1內(340 mA和450 mA)和組2內(380 mA和450 mA)比較差異均無統計學意義(P值均＞0.05);組3內300 mA的評分為(2.92±0.62)、(2.92±0.62)、(2.64 ±0.84)、(2.72±0.82)、(2.63±0.71)、(2.51±0.84)、(3.04±0.72)、(3.04±0.72)、(2.63±0.71)、(2.52±0.73)、(2.93±0.81)分,450 mA的評分為(3.93±0.72)、(3.94±0.72)、(3.41±0.64)、(3.43±0.61)、(3.62±0.93)、(3.63 ±0.71)、(3.93±0.81)、(3.93±0.81)、(3.43±0.61)、(3.52±0.92)、(3.84±0.82)分,二者比較差異均有統計學意義(Z=-2.449～-2.236,P值均＜0.05).結論 降低管電流以降低腹部CT掃描輻射劑量的方案是可行和有效的,腹部CT掃描閤理的管電流條件為340 mA.
목적 이용측량모형탐토64층라선CT복부소묘합리적관전류치.방법 (1)모형연구:설치관전압위120 kVp,관전류분별위450、400、380、360、340、320、300、280 mA,소묘측량모형중적CTP515저대비분변솔모괴,3명열편자독립평개도상질량,획득최우관전류조건급도치도상질량발생질변적관전류구간치후응용우림상연구.(2)림상연구:선취3개월내행2차복부CT평소검사환자45례.수차검사균채용관전류450 mA,제2차검사채용완전수궤화분조방법파수검자분위3조,매조각15례,관전류설치조l사용최우관전류,조2사용최우관전류+구간치,조3사용최우관전류-구간치,3명열편자대간문、이선、신상겁3개층면진행진단접수솔평개,대복주동맥、문정맥、간장、비장、담낭、이선、신피질、신수질진행도상주관조성평개.도상질량비교채용질화검험,각조간수검자개체화인소비교채용방차분석.결과 (1)복부CT소묘최우소묘관전류위340 mA,도치도상질량발생질변적구간치위40 mA.(2)대복주동맥、문정맥주간、간장、비장、이선、담낭、신피질、신수질급간문、이선、신상겁3개층면적도상질량평분,조1내(340 mA화450 mA)화조2내(380 mA화450 mA)비교차이균무통계학의의(P치균＞0.05);조3내300 mA적평분위(2.92±0.62)、(2.92±0.62)、(2.64 ±0.84)、(2.72±0.82)、(2.63±0.71)、(2.51±0.84)、(3.04±0.72)、(3.04±0.72)、(2.63±0.71)、(2.52±0.73)、(2.93±0.81)분,450 mA적평분위(3.93±0.72)、(3.94±0.72)、(3.41±0.64)、(3.43±0.61)、(3.62±0.93)、(3.63 ±0.71)、(3.93±0.81)、(3.93±0.81)、(3.43±0.61)、(3.52±0.92)、(3.84±0.82)분,이자비교차이균유통계학의의(Z=-2.449～-2.236,P치균＜0.05).결론 강저관전류이강저복부CT소묘복사제량적방안시가행화유효적,복부CT소묘합리적관전류조건위340 mA.
Objective To investigate the appropriate low tube current of abdominal CT on a 64-slice spiral CT. Methods (1) Phantom study:The phantom Catphan500R was scanned with a fixed 120 kVp,and 450,400,380,360,340,320,300,280 mA, respectively. 15, 9, 8, 7, 6 mm diameter low-contrast objects with 1% contrast were scanned for evaluating image quality. CT images were graded in terms of lowcontrast conspicuity by using a five-point scale. Statistical analyses were performed to determine the appropriate tube current and the interval leading to the qualitative change. (2) Clinical study: 3 groups of 45 patients who had 2 examinations of non-enhanced abdominal CT within 3 months were enrolled. All patients were scanned with 450 mA at first scanning. For the second scanning, group-1 was scanned with optimal tube current, group-2 was scanned with optimal tube current plus interval, group-3 was scanned with optimal tube current sinus interval. CT images were graded in terms of the diagnostic acceptability at three anatomic levels including porta hepatis, pancreas and the upper pole kidney, and the image noises of eight organs including abdominal aorta, portal vein, liver, spleen, gallbladder, pancreas, renal cortex, renal medulla were graded by using a five-point scale. The image quality was compared with non-parametric rank sum test,and the individual factors of the patients were compared with the A VONA. Results (1) The optimal tube current and interval leading to the qualitative change were 340 mA and 40 mA respectively. (2) There were no significant differences in image quality between 340 mA and 450 mA in group-1, between 380 mA and 450 mA in group-2 (P ＞ 0. 05). There was significant difference in image quality between 300 mA and 450 mA in group-3 (the mean scores for 300 mA were 2. 92 ± 0. 62,2.92 ± 0. 62,2.64 ± 0. 84,2. 72 ±0.82,2.63 ±0.71,2.51 ±0.84,3.04 ±0.72,3.04 ±0.72,2.63 ±0.71,2.52 ±0.73,2.93 ±0.81respectively; for 450 mA were 3.93 ± 0. 72,3.94 ± 0. 72,3.41 ± 0. 64,3.43 ± 0. 61,3.62 ± 0. 93,3.63 ±0.71,3.93 ±0.81,3.93 ±0.81,3.43 ±0.61,3.52 ±0.92,3.84 ±0.82 respectively) (Z = -2.449 to - 2. 236, P ＜ 0. 05). Conclusion Radiation dose can be effectively reduced by using an appropriate and lower current of 340 mA.
