Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, China.
Department of Radiology, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, China.
Abdom Radiol (NY). 2022 Apr;47(4):1276-1290. doi: 10.1007/s00261-021-03397-x. Epub 2022 Feb 15.
The overexpression of aquaporin-1 (AQP1) is associated with poor prognosis in rectal cancer. This study aimed to explore the value of multi-parameter diffusion and perfusion MRI and radiomics models in predicting AQP1 high expression.
This prospective study was performed from July 2019 to February 2021, which included rectal cancer participants after preoperative rectal MRI, with diffusion-weighted imaging, intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI), and dynamic contrast-enhanced (DCE) sequences. Radiomic features were extracted from MR images, and immunohistochemical tests assessed AQP1 expression. Selected quantitative MRI and radiomic features were analyzed. Receiver operating characteristic (ROC) curves evaluated the predictive performance. The nomogram performance was evaluated by its calibration, discrimen, and clinical utility. The intraclass correlation coefficient evaluated the interobserver agreement for the MRI features.
110 participants with the age of 60.7 ± 12.5 years been enrolled in this study. The apparent diffusion coefficient (ADC), IVIM_D, DKI_diffusivity, and DCE_Ktrans were significantly higher in participants with high AQP1 expression than in those with low expression (P < 0.05). ADC (b = 1000, 2000, and 3000 s/mm), IVIM_D, DKI_diffusivity, and DCE_Ktrans were positively correlated (r = 0.205, 0.275, 0.37, 0.235, 0.229, and 0.227, respectively; P < 0.05), whereas DKI_Kurtosis was negatively correlated (r = - 0.22, P = 0.021) with AQP1 expression. ADC (b = 3000 s/mm), IVIM_D, DKI_ diffusivity, DKI_Kurtosis, and DCE_Ktrans had moderate diagnostic efficiencies for high AQP1 expression (AUC = 0.715, 0.636, 0.627, 0.633, and 0.632, respectively; P < 0.05). The radiomic features had excellent predictive efficiency for high AQP1 expression (AUC = 0.967 and 0.917 for training and validation). The model-based nomogram had C-indexes of 0.932 and 0.851 for the training and validation cohorts, which indicated good fitting to the calibration curves (p > 0.05).
Diffusion and perfusion MRI can indicate the aquaporin-1 expression in rectal cancer, and radiomic features can enhance the predictive efficiency for high AQP1 expression. A nomogram for high aquaporin-1 expression will improve clinical decision-making.
水通道蛋白-1（AQP1）的过表达与直肠癌预后不良有关。本研究旨在探讨多参数扩散和灌注 MRI 及放射组学模型在预测 AQP1 高表达中的价值。
本前瞻性研究于 2019 年 7 月至 2021 年 2 月进行，纳入了直肠 MRI 术前的直肠癌患者，包括扩散加权成像、体素内不相干运动（IVIM）、扩散峰度成像（DKI）和动态对比增强（DCE）序列。从 MR 图像中提取放射组学特征，并通过免疫组织化学检测评估 AQP1 表达。选择定量 MRI 和放射组学特征进行分析。受试者工作特征（ROC）曲线评估预测性能。通过校准、判别和临床实用性评估列线图的性能。组内相关系数评估 MRI 特征的观察者间一致性。
本研究共纳入了 110 名年龄为 60.7±12.5 岁的参与者。在 AQP1 高表达组中，表观扩散系数（ADC）、IVIM_D、DKI_diffusivity 和 DCE_Ktrans 明显高于低表达组（P<0.05）。ADC（b=1000、2000 和 3000 s/mm）、IVIM_D、DKI_diffusivity 和 DCE_Ktrans 呈正相关（r=0.205、0.275、0.37、0.235、0.229 和 0.227，均 P<0.05），而 DKI_Kurtosis 与 AQP1 表达呈负相关（r=-0.22，P=0.021）。ADC（b=3000 s/mm）、IVIM_D、DKI_diffusivity、DKI_Kurtosis 和 DCE_Ktrans 对 AQP1 高表达具有中等诊断效能（AUC=0.715、0.636、0.627、0.633 和 0.632，均 P<0.05）。放射组学特征对 AQP1 高表达具有优异的预测效能（训练和验证集的 AUC 分别为 0.967 和 0.917）。基于模型的列线图在训练和验证队列中的 C 指数分别为 0.932 和 0.851，表明与校准曲线拟合良好（p>0.05）。
扩散和灌注 MRI 可反映直肠癌中 AQP1 的表达，放射组学特征可提高对 AQP1 高表达的预测效能。AQP1 高表达的列线图将改善临床决策。
