不同采集条件对PET/CT中CT线性影响的研究  

Research on influences of different acquisition conditions on CT linearity in PET/CT

作　　者：张连宇[1,2] 梁子威 耿建华[1,3] 王弈斌[1] 吴宁[1,2] 郑容[3] 周纯武[2] 

机构地区：[1]中国医学科学院肿瘤医院PET-CT中心,北京100021 [2]中国医学科学院肿瘤医院影像诊断科,北京100021 [3]中国医学科学院肿瘤医院核医学科,北京100021

出　　处：《中国医学装备》2015年第6期54-57,共4页China Medical Equipment

基　　金：国际科技合作项目(2009DFA32960)"PET/CT脑分子影像研究与应用平台及针灸中枢机理探索";中国癌症基金会北京希望马拉松专项基金(LC2013A13)"PET/CT的辐射剂量和图像质量的模型研究"

摘　　要：目的：探索不同采集条件下PET／CT中CT的CT值线性表现，为保障图像质鼍提供实验依据。方法：采用GE Discovery ST－16型号的PET／CT系统，对Catpilan 500型号CT质量模体进行34次扫描，固定管电胜（120kV），在螺距为0．938、1．375、1．75时，管电流从30～210mA，以20mA为间隔，分别进行30组扫描；固定管电流及螺距，管电流150mA，螺距为1．75，管电惟分别为80kV、100kV、120kV及140kV，分别进行4组扫描。测量CT质量模体中CTP401模块内4种物质的CT值，计算对比度标度。结果：固定管电压，4种物质的CT值及对比度标度基本不随管电流及螺距变化，固定管电流及螺距，4种物质的CT值及对比度标度随管电压改变，管电压升高对比度标度降低。结论：CT值线性随管电压政变而变化，不随管电流及螺距改变而变化。Objective： To explore the linearity manifestation of CT in PET/CT under various scan-conditions to provide the experimental data to guarantee the image quality. Methods： PET/ CT system of GE Discovery ST-16 was used to scan the phantom of Catphan 500. Thirty groups of scanning were performed at Pitch 0.938, 1.375, 1.75, from 30 to 210 mA, at an interval of 20 mA, respectively, when tube voltage was fixed at 120 kV In addition, four groups of scanning were perfomed at the tube voltage （kV） were 80, 100, 120 and 140 kV, respectively when the tube current was fixed at 150 mA and Pitch was fixed at 1.75. Measuring the CT number of four materials in the module CTP401. the contrast scales were calculated. Results： The CT number of the four materials and contrast scale didn＇t change with the tube current and Pitch when the tube voltage was fixed. However, when the tube current and Pitch were fixed, the CT number and contrast scale changed with the tube voltage. The contrast scale was decreased with the increasing tube voltage. Conclusion： CT number linearity changed with the tube voltage and was independent of the tube current and Pitch.

关 键 词：正电子发射断层摄影术 体层摄影术 X射线计算机 CT值线性 管电压 管电流 螺距 

分 类 号：R814.42[医药卫生—影像医学与核医学]