摘要
目的探讨6种计算对比噪声比(CNR)公式在颅脑能谱CT单能量成像中的应用价值。方法对52例患者行颅脑能谱CT,之后间隔10 keV重建40~140 keV单能量图像,测量其中脑白质、颞部肌肉、脑脊液、皮下脂肪及颅外空气的CT值及噪声值。分别采用公式A(A组)、B(B组)、C(C组)、Da(Da组)、Db(Db组)、Dc(Dc组)计算CNR值,以Optimal CNR曲线(Optimal CNR组)为参考,比较各组CNR值差异,分析各组与Optimal CNR组间CNR值的相关性及一致性。结果不同能量下,采用不同公式计算所得CNR值差异均有统计学意义(P均<0.01)。不同能量下,A、B、C、Da、Db、Dc组与Optimal CNR组间CNR值均存在正相关(r=0.97±0.02、0.94±0.01、0.94±0.01、0.67±0.01、0.39±0.01、0.59±0.01,P均<0.05),与Optimal CNR组CNR值均具有不同程度一致性(ICC=0.97±0.02、0.89±0.01、0.67±0.01、0.54±0.02、0.13±0.01、0.47±0.02,P均<0.05)。结论颅脑能谱CT单能量成像中,以公式A计算得出的CNR值与Optimal CNR软件结果的一致性及相关性最佳;实际应用中需根据具体情况及研究目的选择CNR计算公式。
Objective To analyze the application value of 6 common formulas for calculating contrast-to-noise ratio(CNR)of energy spectrum brain CT single energy imaging.Methods Brain energy spectrum CT images were obtained in 52 patients,and single-energy images of 40-140 keV(10 keV interval)were reconstructed.CT values and the corresponding noises of white matter,temporal muscles,cerebrospinal fluid,subcutaneous fat and extracranial air were respectively measured,and formulas A(group A),B(group B),C(group C),Da(group Da),Db(group Db)and Dc(group Dc)were used to calculate CNR values.CNR values were compared among groups based on Optimal CNR curve(Optimal CNR group),and the relative correlation and consistency of CNR value of each group and Optimal CNR group were observed.Results CNR values of each group at different energy levels were statistical different(all P<0.01).CNR values of group A,group B,group C,group Da,group Db,group Dc were all correlated with Optimal CNR group(r=0.97±0.02,0.94±0.01,0.94±0.01,0.67±0.01,0.39±0.01,0.59±0.01,all P<0.05)and showed various degrees of consistency with Optimal CNR group(ICC=0.97±0.02,0.89±0.01,0.67±0.01,0.54±0.02,0.13±0.01,0.47±0.02,all P<0.05).Conclusion For brain energy spectrum CT single-energy imaging,CNR value calculated by formula A had the best consistency and correlation with the results of Optimal CNR software.CNR calculation formulas should be selected according to patient condition and research purposes in clinic practice.
作者
姚金磊
陈丽
吴佰超
YAO Jinlei;CHEN Li;WU Baichao(Department of CT,Liaocheng Hospital of Traditional Chinese Medicine,Liaocheng 252000,China;Department of Radiology,Liaocheng Hospital of Traditional Chinese Medicine,Liaocheng 252000,China;Department of Emergency,Liaocheng Hospital of Traditional Chinese Medicine,Liaocheng 252000,China)
出处
《中国医学影像技术》
CSCD
北大核心
2020年第10期1537-1541,共5页
Chinese Journal of Medical Imaging Technology
作者简介
第一作者:姚金磊(1985-),男,山东聊城人,本科,主治医师。研究方向:CT诊断学;通信作者:姚金磊,聊城市中医医院CT室,252000。E-mail:942845165@qq.com。
