摘要
目的:比较CT和核医学(NM)阈值两种方法勾画高鍀酸盐(99Tcm-O4-)单光子发射型电子计算机断层扫描/CT(^(99)Tc^(m)-O_(4)^(-)SPECT/CT)放射性靶区,确定99Tcm-O4-SPECT/CT高摄取病灶的最佳NM阈值。方法:采用美国电气制造商协会与国际电工委员会(NEMA/IEC)图像质量模型,对直径分别为37 mm、28 mm、22 mm、17 mm、13 mm和10 mm的6个热球以及本底分别灌注126.54 kBq/ml和7.03 kBq/ml的99Tcm-O4-(球/本底比为18∶1),通过SPECT/CT进行断层图像采集和重建。于CT图像上采用球形工具勾画热球靶区感兴趣体积(VOI);并于SPECT图像上采用NM阈值方法勾画热球靶区VOI,阈值范围为10%~90%,间隔5%。以热球实际体积为“金标准”,确定最佳NM阈值。采用曲线拟合分析最佳NM阈值与热球大小之间的关系。结果:热球靶区VOI勾画的准确性和定量准确性受勾画方法和热球大小的影响。最佳NM阈值(热球直径由小到大)分别为80%、70%、60%、50%、45%和40%。与CT勾画方法比较,最佳NM阈值方法勾画热球VOI与实际体积更接近,误差为-5.9%~-16.7%。曲线拟合分析结果显示,最佳NM阈值与热球直径之间呈非线性相关,函数关系为幂函数形式,预估曲线模型为:y=2.8065x^(-0.546),R^(2)=0.99(P<0.001)。最佳NM阈值方法勾画的定量准确性更高,其平均恢复系数(RC_(mean))分别为0.29、0.55、0.72、0.82、0.89和0.93(热球直径由小到大)。结论:对于^(99)Tc^(m)-O_(4)^(-)SPECT/CT显像,与CT勾画方法比较,最佳NM阈值方法在靶区VOI测定和SPECT/CT定量方面是一种更为精确的测量方法,最佳NM阈值与病灶大小之间的函数关系为临床准确勾画病灶靶区VOI提供了可靠依据。
Objective:To compare the radioactive target volume of computed tomography(CT)and nuclear medicine(NM)threshold value in delineating radioactive target volume of 99Tcm-O4-single photon emission computed tomography/computed tomography(SPECT/CT),and determine the optimal NM threshold value of 99Tcm-O4-SPECT/CT high-uptake lesions.Methods:The model of image quality of National Electrical Manufactures Association/International Electrotechnical Commission(NEMA/IEC)was adopted.And the six hot spheres with different diameters of 37,28,22,17,13,10mm and the background were perfused 126.54 kBq/ml and 7.03 kBq/ml of ^(99)Tc^(m)-O_(4)^(-)(Sphere to background ratio was 18:1).SPECT/CT was adopted to implement cross-sectional image collection and reconstruction.The spherical tool was adopted to delineate volume of interesting(VOIs)of target volume of hot spheres on CT image.And the NM threshold value method was adopted to delineate target volume VOI of hot sphere on SPECT image,and the range of threshold value was 10-90%,and the interval was 5%.The actual volume of hot sphere was used as“golden standard”to determine the optimal NM threshold value.And the curve-fitting was adopted to analyze the relationship between the optimal NM threshold value and the size of hot sphere.Results:The accuracy and quantitative accuracy of the delineation of hot sphere target volume VOIs were influenced by the delineation method and the size of hot sphere size.The optimal NM threshold values were 80%,70%,60%,50%,45%and 40%(the diameter of hot sphere grew from small to big),respectively.Compared with CT delineation method,the hot sphere VOI that was delineated by the optimal NM threshold value method was closer to actual volume,and the error was-5.9%--16.7%.The result of curve fitting analysis indicated that the optimal NM threshold value appeared non-linear correlation with the diameter of hot sphere.And the function relationship was power function,and the estimated curve model was y=2.8065x^(-0.546),R^(2)=0.99(P<0.001).The quantitative accu
作者
邓惠兴
吉婷
王岐
杨爱民
DENG Hui-xing;JI Ting;WANG Qi(Department of Nuclear Medicine,The First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061,China.)
出处
《中国医学装备》
2021年第9期38-42,共5页
China Medical Equipment
