Comparison of Perfusion, Diffusion, and MR Spectroscopy between Low-Grade Enhancing Pilocytic Astrocytomas and High-Grade Astrocytomas

摘要: BACKGROUND AND PURPOSE: The differentiation of pilocytic astrocytomas and high-grade is sometimes difficult. There are limited comparisons in the literature advanced MR imaging findings versus astrocytomas. purpose this study was to assess imaging, PWI, DWI, spectroscopy characteristics compared with MATERIALS METHODS: Sixteen patients 22 (8–66 years age; mean, 36 ± 17 years) were evaluated by using a 1.5T unit. used determine differences between sensitivity, specificity, area under receiver operating characteristic curve all analyzed parameters at respective cutoff values determined. RESULTS: relative cerebral blood volume significantly lower (1.4 0.9 3.3 1.4; P = .0008). ADC higher (1.5 × 10−3 0.4 1.2 0.3; .01). lipid-lactate tumor/creatine tumor ratios (8.3 11.2 43.3 59.2; .03). threshold ≥1.33 for provide positive predictive values, negative 100%, 67%, 87%, respectively, differentiating from optimal ≤1.60 ADC, ≥7.06 tumor, ≥2.11 tumor/lipid-lactate normal contralateral tissue. CONCLUSIONS: Lower favor diagnosis astrocytoma, while plus necrosis