Combining quantitative susceptibility mapping, arterial spin labeling and diffusion weighted imaging for distinguishing true progression from pseudoprogression in high-grade gliomas.

Purpose: This study aimed to evaluate and compare the diagnostic performance of quantitative susceptibility mapping (QSM), 3D pseudo-continuous arterial spin labeling (3D-pCASL), and diffusion-weighted imaging (DWI) in differentiating true progression (TP) from pseudoprogression (PsP) in postoperative high-grade glioma (HGG) patients.

Methods: Forty-nine postoperative HGG patients with newly enhanced lesions were enrolled. All participants underwent conventional MRI, QSM, 3D-pCASL, and DWI. Final diagnoses were confirmed by 6-month longitudinal MRI follow-up or histopathology from reoperation. Quantitative parameters-including the hemorrhagic foci area proportion (proQSM), magnetic susceptibility (SUS), relative maximum cerebral blood flow (rCBF_max), and relative minimum apparent diffusion coefficient (rADC_min)-were compared between TP and PsP groups using independent samples t-tests. Diagnostic efficacy was assessed via receiver operating characteristic (ROC) curve analysis, and interparametric correlations were evaluated.

Results: TP lesions exhibited significantly lower proQSM (p < 0.001) and higher rCBF_max (p < 0.001) than PsP, with area under the curve (AUC) values of 0.891 and 0.881, respectively. While rADC_min was marginally reduced in TP (p < 0.05), SUS showed no intergroup difference (p = 0.164). Combining proQSM with rCBF_max significantly improved diagnostic accuracy (AUC = 0.948). Furthermore, proQSM, rADC_min showed a negative correlation with rCBF_max, respectively. (p < 0.0001).

Conclusion: proQSM and rCBF_max serve as complementary biomarkers for TP and PsP differentiation. The integration of QSM and ASL imaging significantly improves diagnostic accuracy compared to conventional parameters, providing a noninvasive strategy for postoperative HGG surveillance.