Background: Alterations in the vascular microenvironment of cancer have gradually gained widespread attention in oncology research, and early qualitative diagnosis using noninvasive examination techniques is crucial in clinical practice. This study aimed to explore the value of quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of vascular architecture of solid solitary pulmonary nodules (SSPNs).

Methods: DCE-MRI scan images of a total of 79 patients with SSPNs from November 2021 to December 2023 were prospectively analyzed. Quantitative permeability parameters K^trans, K_ep, and V_e values of the lesions were measured, labeled immunohistochemically with CD31 microvessel density (CD31-MVD), smooth muscle actin microvessel density (SMA-MVD), and vascular endothelial growth factor (VEGF), and quantitative values of vascular architectural parameters were obtained using the image analysis software Image-J. The diagnostic efficacy of quantitative permeability parameters for the diagnosis of malignant SSPNs was analyzed by receiver operating characteristic (ROC) curves using surgical pathology findings as the gold standard for the diagnosis of malignant SSPNs. Spearman’s correlation analysis was used to evaluate the relationship between quantitative permeability parameters and vascular construct parameters.

Results: The study included 51 female patients (64.6%) with a mean age of 50.5±11.5 years. Only 21 patients (26.6%) had a smoking history, and 30 patients (38.0%) had a normal weight. Statistically significant differences were found between benign and malignant SSPNs subgroups in K^trans and V_e values in quantitative permeability parameters, and in SMA-MVD and microvascular perfusion index (MPI) in vascular conformation parameters (P<0.05). K^trans and V_e values showed high diagnostic value for malignant SSPNs [area under the curve (AUC), 0.813 and 0.759]. K^trans, K_ep, and V_e were significantly positively correlated with CD31-MVD, with r-values of 0.857, 0.830, and 0.798 (P<0.05); they were also significantly positively correlated with VEGF, with r-values of 0.851, 0.859, and 0.764 (P<0.05); and K_trans and K_ep were significantly negatively correlated with MPI, with r-values were −0.779 and −0.864 (P<0.05).

Conclusions: The quantitative permeability parameters of DCE-MRI correlate with some of the vascular architectural parameters, and magnetic resonance image-based quantification of pulmonary nodal vascular architecture provides a noninvasive method for the differential diagnosis of SSPNs.

Keywords: Solid solitary pulmonary nodules (SSPNs); dynamic contrast enhanced magnetic resonance imaging (DCE-MRI); vascular architecture; quantitative permeability parameters; immunohistochemistry