Exploring the value of multiparametric quantitative MRI in the assessment of pancreatic ductal adenocarcinoma fibrosis grading

To analyze the performance of multiparametric magnetic resonance imaging (MRI) in quantification of pancreatic ductal adenocarcinoma (PDAC) fibrosis grading.

This prospective study enrolled 79 patients with PDAC confirmed by pathology. Multiparametric MRI including native T1 mapping, intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), diffusion kurtosis imaging diffusion-weighted imaging (DKI-DWI), and enhanced T1 mapping were performed before surgery. Masson staining was used to evaluate intratumoral fibrosis content and classified into low- and high-fibrosis groups. MRI parameters were compared between the two groups using multivariable logistic regression analysis. The correlations between fibrosis content and MRI parameters were evaluated using Pearson’s correlation.

D, f, mean diffusion (MD), and enhanced T1 mapping were lower in the high-fibrosis group than in the low-fibrosis group (p < 0.001, p < 0.001, p < 0.001, p = 0.026, respectively). Native T1 mapping and extracellular volume (ECV) were opposite (All p < 0.001). No significant differences in the rest. Multivariable logistic regression revealed that native T1 mapping, MD, and ECV were independent discriminators for PDAC fibrosis grading (p = 0.037, p = 0.031, p = 0.014, respectively); the area under the curve (AUC) of native T1 mapping, MD and ECV was 0.863, 0.798, and 0.929. Among them, ECV had an extremely strong positive correlation with intratumoral fibrosis content. Native T1 mapping and MD were correlated strongly with fibrosis content (positive and negative, respectively).

ECV had the highest assessing performance for grading fibrosis in PDAC compared to other MRI parameters, and has the potential to be an imaging biomarker for predicting the fibrosis content of PDAC.

Question The relationship between fibrosis grade of PDAC and quantitative MRI parameters based on T1 mapping and diffusion imaging has not been fully investigated.

Findings ECV performed the best in distinguishing between fibrosis grade and increased as interstitial fibrosis increased; clinical indicators offered no added value.

Clinical relevance Quantitative MRI parameters provide significant value in evaluating the fibrosis grade of PDAC, which bears significant implications for preoperative risk stratification and the selection of personalized treatment strategies for patients.