Objective

To investigate the effect of inter-operator variability in arterial input function (AIF) definition on kinetic parameter estimates (KPEs) from dynamic contrast-enhanced (DCE) MRI in patients with high-grade gliomas.

Methods

The study included 118 DCE series from 23 patients. AIFs were measured by three domain experts (DEs), and a population AIF (pop-AIF) was constructed from the measured AIFs. The DE-AIFs, pop-AIF and AUC-normalized DE-AIFs were used for pharmacokinetic analysis with the extended Tofts model. AIF-dependence of KPEs was assessed by intraclass correlation coefficient (ICC) analysis, and the impact on relative longitudinal change in K^trans was assessed by Fleiss’ kappa (κ).

Results

There was a moderate to substantial agreement (ICC 0.51–0.76) between KPEs when using DE-AIFs, while AUC-normalized AIFs yielded ICC 0.77–0.95 for K^trans, k_ep and v_e and ICC 0.70 for v_p. Inclusion of the pop-AIF did not reduce agreement. Agreement in relative longitudinal change in K^trans was moderate (κ = 0.591) using DE-AIFs, while AUC-normalized AIFs gave substantial (κ = 0.809) agreement.

Discussion

AUC-normalized AIFs can reduce the variation in kinetic parameter results originating from operator input. The pop-AIF presented in this work may be applied in absence of a satisfactory measurement.

中文翻译：

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动态对比增强 MRI 中动脉输入函数的算子依赖性

客观的

研究动脉输入功能 (AIF) 定义的操作者间变异性对高级别胶质瘤患者动态对比增强 (DCE) MRI 的动力学参数估计 (KPE) 的影响。

方法

该研究包括来自 23 名患者的 118 个 DCE 系列。AIF 由三位领域专家 (DE) 测量，并从测量的 AIF 构建总体 AIF (pop-AIF)。DE-AIF、pop-AIF 和 AUC 归一化的 DE-AIF 用于扩展 Tofts 模型的药代动力学分析。通过组内相关系数 (ICC) 分析评估 KPE 的 AIF 依赖性，并通过 Fleiss' kappa ( κ ) 评估对K^反式相对纵向变化的影响。

结果

使用 DE-AIF 时，KPE 之间存在中等至显着的一致性（ICC 0.51-0.76），而 AUC 归一化的 AIF 对于K ^trans、k _ep和v _{e的 ICC 为 0.77-0.95，对于}v _p的 ICC 为 0.70 。包含 pop-AIF 并没有降低协议。使用 DE-AIF 时， K ^trans相对纵向变化的一致性适中（κ  = 0.591），而 AUC 标准化 AIF 给出了实质性（κ  = 0.809）一致性。

讨论

AUC 标准化 AIF 可以减少源自操作员输入的动力学参数结果的变化。这项工作中提出的 pop-AIF 可以在没有令人满意的测量的情况下应用。