Vascular habitat analysis using dynamic susceptibility contrast-enhanced perfusion MRI for differentiating glioblastoma from solitary brain metastases

Objective To investigate tumor vascular habitat parameters based on dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) for differentiating glioblastoma (GBM) from solitary brain metastasis (SBM). Methods In this single-center retrospective study, imaging data from 141 patients with pathologically or clinically confirmed malignant brain tumors (74 GBM, 67 SBM) were analyzed. The hemodynamic tissue signature (HTS) method was used to segment the lesions and construct four tumor vascular habitats: high angiogenic tumor (HAT), low angiogenic tumor (LAT), potentially infiltrated peripheral edema (IPE), and vasogenic peripheral edema (VPE). Pearson correlation analysis was used to quantify the correlations among habitat hemodynamic parameters. Habitat characteristic parameters were calculated, and ROC were plotted to evaluate the diagnostic performance. A nomogram model was constructed using logistic regression. Results GBM exhibited significantly higher median relative cerebral blood volume (rCBV median ) and median relative cerebral blood flow (rCBF median ) than SBM across all four habitat regions (all p < 0.001). In terms of volumetric parameters, the ratio of IPE volume to peritumoral volume ( V (IPE) / V (P) ) was significantly higher in the GBM group ( p < 0.001). Among individual habitat parameters, LAT rCBF median showed the best diagnostic performance with an AUC of 0.786 (95% CI: 0.709-0.850). In the GBM group, the perfusion parameters of the IPE and VPE were significantly positively correlated with those of the HAT, whereas no such correlation was found in the SBM group. A nomogram incorporating lesion location, enhancement pattern, and LAT-rCBF median yielded an AUC of 0.857 (95% CI: 0.79-0.92) for distinguishing GBM from SBM, with good calibration. Conclusion Tumor vascular habitat parameters based on DSC-PWI demonstrate significant differences between newly diagnosed GBM and SBM, and the nomogram shows certain value in differentiating between the two tumor types.