Jackson A, Jayson G C, Li K L, Zhu X P, Checkley D R, Tessier J J L, Waterton J C
Division of Imaging Science and Biomedical Engineering, Stopford Medical School, University of Manchester, Manchester M13 9PT, UK.
Br J Radiol. 2003 Mar;76(903):153-62. doi: 10.1259/bjr/70653746.
We have investigated the reproducibility of dynamic contrast enhanced imaging techniques in nine patients with cerebral glioma. Patients were imaged twice with a 2 day interval between scans. Maps were produced of the time taken to achieve 90% enhancement (T90), the maximal intensity change per time interval ratio (MITR), the volume transfer coefficient between plasma and the extravascular extracellular space (K(trans)) and the extravascular extracellular contrast distribution volume, v(e). Measurements of K(trans) greater than 1.2 min(-1) were used to exclude pixels where first pass perfusion effects dominated the measurement. Measures of the test-retest coefficient of variation (CoV) and intraclass correlation coefficients were used to assess reproducibility for measurements from a volume of interest containing enhancing tissue from the whole tumour. MITR showed poor reproducibility (mean CoV 17.9%, 95% confidence limits for group comparisons 20.2%). T90 showed good reproducibility (mean CoV 7.1%, 95% confidence limits for group comparisons 5.2%). Calculated values of K(trans) and v(e) also showed good reproducibility (mean CoV 7.7% and 6.2% respectively, 95% confidence limits for group comparisons 6.2% and 4.8%, respectively). We conclude that the measurements of K(trans) and v(e) derived from pharmacokinetic analysis are sufficiently reproducible to support their use as a biological markers in therapeutic trials.
我们研究了9例脑胶质瘤患者动态对比增强成像技术的可重复性。患者在两次扫描之间间隔2天进行成像。生成了达到90%增强所需时间（T90）、每个时间间隔最大强度变化率（MITR）、血浆与血管外细胞外间隙之间的体积转移系数（K(trans)）以及血管外细胞外对比剂分布容积v(e)的图谱。K(trans)测量值大于1.2 min⁻¹用于排除首次通过灌注效应主导测量的像素。采用重测变异系数（CoV）和组内相关系数来评估来自包含整个肿瘤增强组织的感兴趣体积测量的可重复性。MITR显示出较差的可重复性（平均CoV为17.9%，组间比较的95%置信限为20.2%）。T90显示出良好的可重复性（平均CoV为7.1%，组间比较的95%置信限为5.2%）。计算得到的K(trans)和v(e)值也显示出良好的可重复性（分别为平均CoV 7.7%和6.2%，组间比较的95%置信限分别为6.2%和4.8%）。我们得出结论，药代动力学分析得出的K(trans)和v(e)测量值具有足够的可重复性，以支持它们在治疗试验中作为生物学标志物的应用。
