为了确定定性和定量MRI特征在胰腺导管腺癌（PDAC）患者标准淋巴清扫过程中诊断病理性区域淋巴结的准确性。此单中心回顾性队列研究纳入2011至2021年内进行胰十二指肠切除术前3个月进行胰腺MRI的所有成年患者。两个受过专业培训的腹部放射科医生独立地检查标准淋巴清扫下的区域淋巴结的以下定性特征：异质性T2信号、圆形、不明显的边缘、围绕结节的脂肪绕索和受限的扩散大于脾脏。评估了包括原发肿瘤大小、最大淋巴结短轴和长轴长度、区域淋巴结数量、绝对表观扩散系数（ADC）值和ADC结节与脾信号指数在内的定量特征。分析是以患者为单位进行的，手术病理作为参考标准。在75名患者中，85％（64/75）在组织病理学上呈现区域性淋巴结疾病。 MRI评估的定性变量中没有一项与病理性结节相关。相对于无病理性结节的患者，中央肿瘤最大直径的中位数略大（18 mm（10-42 mm）vs 16 mm（9-22 mm），p = 0.027）。其他定量特征中没有一项与病理性结节相关。放射科医生的意见与病理性结节无关（p=0.520）。观察者间一致性为一般水平（kappa=0.257）。淋巴结形态特征和放射科医生对MRI的看法在诊断PDAC区域性淋巴结疾病方面的价值有限。鉴于这些患者中病理性淋巴结的预后影响，需要改进诊断技术。• 在体内其他恶性肿瘤中通常评估的多个淋巴结形态特征可能不适用于评估胰腺导管腺癌淋巴结疾病。• 在MRI上存在或不存在胰腺导管腺癌淋巴结形态特征的观察者间一致性为一般水平（kappa=0.257）。• 在PDAC标准淋巴清扫过程中切除的淋巴结数量比MRI检测到的数量多得多，中位数分别为25和5（p<0.001），这表明需要改进诊断技术以识别PDAC淋巴结疾病。©2023. 作者（们）独家授权欧洲放射学会。

To determine the accuracy of qualitative and quantitative MRI features for the diagnosis of pathologic regional lymph nodes at standard lymphadenectomy in patients with pancreatic ductal adenocarcinoma (PDAC).All adult patients with pancreatic MRI performed from 2011 to 2021 within 3 months of a pancreaticoduodenectomy were eligible for inclusion in this single-center retrospective cohort study. Regional nodes at standard lymphadenectomy were independently reviewed by two fellowship-trained abdominal radiologists for the following qualitative features: heterogeneous T2 signal, round shape, indistinct margin, peri-nodal fat stranding, and restricted diffusion greater than the spleen. Quantitative characteristics including primary tumor size, largest node short- and long-axes length, number of regional nodes, absolute apparent diffusion coefficient (ADC) values, and ADC node-to-spleen signal index were assessed. Analysis was at the patient-level with surgical pathology as the reference standard.Of 75 patients, 85% (64/75) were positive for regional nodal disease on histopathology. None of the qualitative variables evaluated on MRI was associated with pathologic nodes. Median primary tumor maximum diameter was slightly larger for patients with pathologic nodes compared to those without (18 mm (10-42 mm) vs 16 mm (9-22 mm), p = 0.027). None of the other quantitative features was associated with pathologic nodes. Radiologist opinion was not associated with pathologic nodes (p = 0.520). Interobserver agreement was fair (kappa = 0.257).Lymph node morphologic features and radiologist opinion using MRI are of limited value for diagnosing PDAC regional nodal disease. Improved diagnostic techniques are needed given the prognostic implications of pathologic lymph nodes in these patients.• Multiple lymph node morphologic features routinely assessed on MRI for malignancies elsewhere in the body are likely not applicable when assessing for pancreatic ductal adenocarcinoma nodal disease. • Interobserver agreement for the presence or absence of pancreatic ductal adenocarcinoma lymph node morphologic features on MRI is fair (kappa = 0.257). • Many more lymph nodes are resected at PDAC standard lymphadenectomy than are detectable on MRI, median 25 vs 5 (p < 0.001), suggesting improved diagnostic techniques are needed to identify PDAC nodal disease.© 2023. The Author(s), under exclusive licence to European Society of Radiology.