Li Ke, Li Jing, Liu Xiaoling, Chen Jiafei, Chen Wei
Department of Radiology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
Department of Medical Imaging, Sichuan Corps Hospital of Chinese People's Armed Police Force, Leshan, Sichuan Province, China.
Abdom Radiol (NY). 2025 Aug 29. doi: 10.1007/s00261-025-05164-8.
To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) parameters combined with clinical information for predicting Ki-67 expression in pancreatic ductal adenocarcinoma (PDAC).
This prospective cohort study enrolled 65 patients with histopathologically confirmed PDAC between January 2024 and May 2025. All patients underwent 3.0T MRI including conventional sequences and advanced diffusion-weighted imaging sequences. Clinical data and laboratory parameters were collected within one week before surgery or biopsy. Ki-67 expression was assessed using immunohistochemical staining with 50% as the cutoff value. Two radiologists independently performed quantitative measurements with excellent inter-observer reliability (ICC > 0.85). Univariate and multivariate logistic regression analyses identified independent predictors. ROC curve analysis and DeLong test evaluated diagnostic performance.
Based on Ki-67 expression threshold of 50%, 48 patients (73.8%) were classified as low expression and 17 patients (26.2%) as high expression. Compared to the low Ki-67 group, the high expression group demonstrated significantly lower monocyte count (0.35 ± 0.09 vs. 0.49 ± 0.16 × 10⁹/L, P = 0.001), higher IVIM f-value (14.08 ± 3.41% vs. 10.90 ± 3.83%, P = 0.004), and lower DKI-MD (1.26 ± 0.17 vs. 1.65 ± 0.17 × 10⁻³ mm²/s, P < 0.001). Individual prediction models achieved AUCs of 0.763 (monocyte count), 0.732 (IVIM f-value), and 0.800 (DKI-MD). The combined prediction model integrating these three parameters demonstrated excellent diagnostic performance with AUC of 0.913 (95% CI: 0.841-0.985), sensitivity of 82.4%, and specificity of 83.3%, significantly outperforming all individual models (P < 0.001).
This multi-parametric combined prediction model achieves excellent diagnostic performance for preoperative non-invasive assessment of Ki-67 expression status in PDAC, providing a reliable tool for precision medicine practice and personalized treatment strategies.
评估体素内不相干运动（IVIM）和扩散峰度成像（DKI）参数联合临床信息对预测胰腺导管腺癌（PDAC）中Ki-67表达的诊断价值。
这项前瞻性队列研究纳入了2024年1月至2025年5月间65例经组织病理学确诊的PDAC患者。所有患者均接受3.0T MRI检查，包括常规序列和高级扩散加权成像序列。在手术或活检前一周内收集临床数据和实验室参数。采用免疫组织化学染色评估Ki-67表达，以50%作为临界值。两名放射科医生独立进行定量测量，观察者间可靠性良好（ICC＞0.85）。单因素和多因素逻辑回归分析确定独立预测因素。ROC曲线分析和DeLong检验评估诊断性能。
基于Ki-67表达阈值50%，48例患者（73.8%）被分类为低表达，17例患者（26.2%）为高表达。与低Ki-67组相比，高表达组的单核细胞计数显著更低（0.3±0.09对0.49±0.16×10⁹/L，P = 0.001），IVIM f值更高（14.08±3.41%对10.90±3.83%，P = 0.004），DKI-MD更低（1.26±0.17对1.65±0.17×10⁻³mm²/s，P＜0.001）。个体预测模型的AUC分别为0.763（单核细胞计数）、0.732（IVIM f值）和0.800（DKI-MD）。整合这三个参数的联合预测模型显示出优异的诊断性能，AUC为0.913（95%CI：0.841-0.985），灵敏度为82.4%，特异性为83.3%，显著优于所有个体模型（P＜0.001）。
这种多参数联合预测模型在术前对PDAC中Ki-67表达状态进行无创评估时具有优异的诊断性能，为精准医学实践和个性化治疗策略提供了可靠工具。
