Magnetic resonance imaging has been used for evaluating of a brain edema in experimental animals to assess cytotoxic and vasogenic edema by the apparent diffusion coefficient (ADC) and T2 imaging. This paper brings information about the effectiveness of methylprednisolone (MP) on experimental brain edema. A total of 24 rats were divided into three groups of 8 animals each. Rats with cytotoxic/intracellular brain edema induced by water intoxication were assigned to the group WI. These rats also served as the additional control group CG when measured before the induction of edema. A third group (WIMP) was intraperitoneally administered with methylprednisolone 100 mg/kg during water intoxication treatment. The group WI+MP was injected with methylprednisolone 50 mg/kg into the carotid artery within two hours after the water intoxication treatment. We evaluated the results in four groups. Two control groups (CG, WI) and two experimental groups (WIMP, WI+MP). Rats were subjected to MR scanning 24 h after edema induction. We observed significantly increased ADC values in group WI in both evaluated areas - cortex and hippocampus, which proved the occurrence of experimental vasogenic edema, while ADC values in groups WIMP and WI+MP were not increased, indicating that the experimental edema was not developed and thus confirming the protective effect of MP.

• MeSH
• Anti-Inflammatory Agents pharmacology   MeSH
• Brain Edema diagnostic imaging   drug therapy   pathology   MeSH
• Hippocampus diagnostic imaging   drug effects   MeSH
• Rats MeSH
• Magnetic Resonance Imaging methods   MeSH
• Methylprednisolone pharmacology   MeSH
• Disease Models, Animal MeSH
• Brain diagnostic imaging   drug effects   MeSH
• Cerebral Cortex diagnostic imaging   drug effects   MeSH
• Rats, Wistar MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Inflammatory Agents MeSH
• Methylprednisolone MeSH

OBJECTIVE: To prospectively determine institutional cut-off values of apparent diffusion coefficients (ADCs) and concentration of tissue metabolites measured by MR spectroscopy (MRS) for early differentiation between glioblastoma (GBM) relapse and treatment-related changes after standard treatment. MATERIALS AND METHODS: Twenty-four GBM patients who received gross total resection and standard adjuvant therapy underwent MRI examination focusing on the enhancing region suspected of tumor recurrence. ADC maps, concentrations of N-acetylaspartate, choline, creatine, lipids, and lactate, and metabolite ratios were determined. Final diagnosis as determined by biopsy or follow-up imaging was correlated to the results of advanced MRI findings. RESULTS: Eighteen (75%) and 6 (25%) patients developed tumor recurrence and pseudoprogression, respectively. Mean time to radiographic progression from the end of chemoradiotherapy was 5.8 ± 5.6 months. Significant differences in ADC and MRS data were observed between those with progression and pseudoprogression. Recurrence was characterized by N-acetylaspartate ≤ 1.5 mM, choline/N-acetylaspartate ≥ 1.4 (sensitivity 100%, specificity 91.7%), N-acetylaspartate/creatine ≤ 0.7, and ADC ≤ 1300 × 10(-6) mm(2)/s (sensitivity 100%, specificity 100%). CONCLUSION: Institutional validation of cut-off values obtained from advanced MRI methods is warranted not only for diagnosis of GBM recurrence, but also as enrollment criteria in salvage clinical trials and for reporting of outcomes of initial treatment.

• MeSH
• Chemoradiotherapy methods   MeSH
• Dacarbazine analogs & derivatives   therapeutic use   MeSH
• Glioblastoma diagnosis   metabolism   therapy   MeSH
• Outcome Assessment, Health Care methods   MeSH
• Middle Aged MeSH
• Humans MeSH
• Neoplasm Recurrence, Local diagnosis   metabolism   prevention & control   MeSH
• Molecular Imaging methods   MeSH
• Biomarkers, Tumor metabolism   MeSH
• Brain Neoplasms diagnosis   metabolism   therapy   MeSH
• Follow-Up Studies MeSH
• Prognosis MeSH
• Proton Magnetic Resonance Spectroscopy methods   MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Temozolomide MeSH
• Treatment Outcome MeSH
• Diffusion Tensor Imaging MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Dacarbazine MeSH
• Biomarkers, Tumor MeSH
• Temozolomide MeSH