探讨瘤周非强化区MRI征象对大脑半球高级别胶质瘤的诊断及鉴别意义OA

Objective:To investigate the diagnostic value of MRI signs in the non-enhancing peritumoral area(NEPA)for differentiating hemispheric high-grade gliomas(HGGs)from solitary brain metastasis.Methods:A retrospective study was conducted on 68 patients with pathologically confirmed hemispheric HGG and 58 patients with solitary brain metastasis who underwent preoperative conventional MRI,DWI and DSC perfusion MRI between January 2021 and December 2024.An external validation set of 44 patients(n=44;24 HGGs and 20 metastases)was additionally created for model validation.A subset also underwent advanced diffusion imaging,APT imaging and ¹H-MRS.Two neuroradiologists blindly evaluated the morphological features of NEPA and measured ADC and rCBV in the inner peritumoral region(IPR)and distal peritumoral region(DPR).Logistic regression and ROC analyses were performed,and optimal cut-off values were determined by the Youden index.Results:Compared with metastases,HGGs more frequently showed heterogeneous FLAIR hyperintensity(82.4％vs.37.9％),a blurred transition zone(73.5％vs.31.0％)and cortical/gray-white junction involvement(50.0％vs.17.2％)in NEPA(all P<0.001).The IPR-ADC was lower in HGGs than in metastases((1.05±0.18)×10-³ mm²/s vs.(1.28±0.20)×10-³ mm²/s),whereas the IPR-rCBV was higher(2.10±0.55 vs.1.25±0.40)(both P<0.001).The combined qualitative-quantitative model achieved an AUC of 0.95(95％CI:0.90～0.98),with a sensitivity of 0.90,specificity of 0.88 and accuracy of 0.89.In the external validation set,the combined model yielded an AUC of 0.92(95％CI:0.83～0.98),with a sensitivity of 0.88,specific-ity of 0.85 and accuracy of 0.86.Conclusion:The morphological features of NEPA combined with diffusion and perfusion quantitative indicators can improve the differential diagnostic efficiency between cerebral hemisphere HGG and single brain metastases.The relatively low ADC and high rCBV in the IPR area may indicate the presence of invasive tumor components outside the enhanced edge.