PURPOSE To compare the tumor size measurements assessed by computed tomography (CT) and magnetic resonance imaging (MRI) versus measurements of resected pathologic specimens from patients with pancreatic ductal adenocarcinoma (PDAC). METHODS This study included 114 patients with histologically confirmed PDAC who underwent contrast-enhanced CT and MRI before surgery. The tumor sizes from CT, MRI, and pathologic specimens were compared by using Bland-Altman analyses and intraclass correlation coefficients (ICCs). The discrepancies in PDAC size between CT/MRI and pathologic specimens were calculated and contributing factors for the discrepancies, including tumor locations (pancreatic head/neck, body, or tail), T stages (T1, T2, or T3), and N stages (N0, N1, or N2), were analyzed with Pearson's correlation coefficients and multivariable linear regression analyses. RESULTS There was significant difference among the mean tumor sizes of three measurements (P < 0.001). The difference in mean tumor size between the pathologic sizes for PDAC was 4.3 mm (ICC 0.67) on CT and 5.8 mm (ICC 0.65) on MRI. Both CT and MRI showed wide ranges of limits of agreement (LOAs) between the pathologic specimens for tumor size measurements (LOAs, - 28.9 to 21.4 and - 29.4 to 17.8, respectively). The tumor size on CT or MRI was estimated to be smaller than that on pathology when the tumor was > 30 mm. The discrepancies in the tumor size estimated between CT/MRI and pathologic specimens were significantly different for tumors of different T stages (P < 0.001). CONCLUSIONS Both contrast-enhanced CT and MRI underestimate the mean tumor size by 4.3 mm and 5.8 mm, respectively, compared to the size of pathologic specimens. A larger tumor size indicates a greater discrepancy in the PDAC size measurements between CT/MRI and pathologic specimens.

中文翻译：

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胰腺腺癌：计算机断层扫描，磁共振成像和病理标本中肿瘤大小的测量差异。

目的比较通过计算机断层扫描（CT）和磁共振成像（MRI）评估的肿瘤大小测量结果与胰腺导管腺癌（PDAC）患者切除的病理标本的测量结果。方法该研究纳入了114例经组织学证实的PDAC的患者，这些患者在手术前接受了对比增强的CT和MRI检查。使用Bland-Altman分析和组内相关系数（ICC）比较了CT，MRI和病理标本的肿瘤大小。计算出CT / MRI与病理标本之间PDAC大小的差异，并为差异提供影响因素，包括肿瘤位置（胰腺头/颈，身体或尾巴），T期（T1，T2或T3）和N期（N0，N1或N2），通过Pearson' 的相关系数和多元线性回归分析。结果三种测量结果的平均肿瘤大小之间存在显着差异（P <0.001）。PDAC的病理尺寸之间的平均肿瘤尺寸差异在CT上为4.3 mm（ICC 0.67），在MRI上为5.8 mm（ICC 0.65）。CT和MRI均显示了用于肿瘤大小测量的病理标本之间的一致性范围（LOAs）（LOAs分别为-28.9至21.4和-29.4至17.8）。当肿瘤> 30 mm时，估计CT或MRI上的肿瘤大小要小于病理上的大小。对于不同T期的肿瘤，CT / MRI与病理标本之间估计的肿瘤大小差异显着不同（P <0.001）。结论增强CT和MRI均低估了平均肿瘤大小4倍。与病理标本的大小相比，分别为3毫米和5.8毫米。较大的肿瘤大小表明CT / MRI与病理标本之间的PDAC大小测量差异更大。