The purpose of this study was to identify the optimal tracer kinetic model from T1 -weighted dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data and evaluate whether parameters estimated from the optimal model predict tumor aggressiveness determined from histopathology in patients with papillary thyroid carcinoma (PTC) prior to surgery. In this prospective study, 18 PTC patients underwent pretreatment DCE-MRI on a 3 T MR scanner prior to thyroidectomy. This study was approved by the institutional review board and informed consent was obtained from all patients. The two-compartment exchange model, compartmental tissue uptake model, extended Tofts model (ETM) and standard Tofts model were compared on a voxel-wise basis to determine the optimal model using the corrected Akaike information criterion (AICc) for PTC. The optimal model is the one with the lowest AICc. Statistical analysis included paired and unpaired t-tests and a one-way analysis of variance. Bonferroni correction was applied for multiple comparisons. Receiver operating characteristic (ROC) curves were generated from the optimal model parameters to differentiate PTC with and without aggressive features, and AUCs were compared. ETM performed best with the lowest AICc and the highest Akaike weight (0.44) among the four models. ETM was preferred in 44% of all 3419 voxels. The ETM estimates of Ktrans in PTCs with the aggressive feature extrathyroidal extension (ETE) were significantly higher than those without ETE (0.78 ± 0.29 vs. 0.34 ± 0.18 min-1 , P = 0.005). From ROC analysis, cut-off values of Ktrans , ve and vp , which discriminated between PTCs with and without ETE, were determined at 0.45 min-1 , 0.28 and 0.014 respectively. The sensitivities and specificities were 86 and 82% (Ktrans ), 71 and 82% (ve ), and 86 and 55% (vp ), respectively. Their respective AUCs were 0.90, 0.71 and 0.71. We conclude that ETM Ktrans has shown potential to classify tumors with and without aggressive ETE in patients with PTC.

中文翻译：

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动态对比增强MRI模型选择，可预测甲状腺乳头状癌的肿瘤侵袭性。

这项研究的目的是从T1加权动态对比增强磁共振成像（DCE-MRI）数据中确定最佳示踪剂动力学模型，并评估根据最佳模型估算的参数是否可预测根据甲状腺乳头状癌组织病理学确定的肿瘤侵袭性手术前的癌（PTC）。在这项前瞻性研究中，在进行甲状腺切除术之前，对18例PTC患者进行了3T MR扫描仪的DCE-MRI预处理。该研究得到机构审查委员会的批准，并获得所有患者的知情同意。比较两室交换模型，隔室组织吸收模型，扩展Tofts模型（ETM）和标准Tofts模型，以修正的PTC Akaike信息准则（AICc）为基础确定最佳模型。最佳模型是具有最低AICc的模型。统计分析包括成对和不成对的t检验以及方差的单向分析。Bonferroni校正用于多个比较。根据最佳模型参数生成接收器工作特性（ROC）曲线，以区分具有和不具有侵略性特征的PTC，并比较了AUC。在这四个模型中，ETM的AICc最低，Akaike重量最高（0.44），表现最佳。在所有3419个体素中，有44％喜欢使用ETM。具侵袭性甲状腺功能外扩展（ETE）的PTC中，Ktrans的ETM估计值显着高于无ETE的PTC（0.78±0.29 vs. 0.34±0.18 min-1，P = 0.005）。根据ROC分析，将在有无ETE和无ETE的PTC之间进行区分的Ktrans，ve和vp的临界值确定为0。45分钟-1、0.28和0.014。敏感性和特异性分别为86％和82％（Ktrans），71％和82％（ve），86％和55％（vp）。它们各自的AUC分别为0.90、0.71和0.71。我们得出的结论是，ETM Ktrans在PTC患者中显示出有或没有侵袭性ETE的肿瘤分类潜力。