الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Despite the excellent soft tissue contrast provided by MRI, the sensitivity and specificity with which this modality defines tumor type and grade is limited, Overcoming these problems requires the development of new imaging modalities that highlight functional or metabolic properties of the tumor. Advanced magnetic resonance imaging (MRI) techniques, such as MR spectroscopy, diffusion and perfusion MR imaging techniques can give important in vivo physiologic and metabolic information, complementing morphologic findings from conventional MRI in the clinical setting. Perfusion-weighted imaging (PWI) is a new tool which provides information about the hemodynamics of anatomic tissue or lesions and is mainly used in the assessment of disturbed cerebral hemodynamics. This study aimed to assess the role of MR perfusion in evaluation and differentiation of intra axial brain tumors, grading of glioma, the role of MR perfusion in helping guide tumor biopsy assessing, true lesion extent and in differentiating treatment effects, such as radiation necrosis from tumor recurrence. The study included 70 patients with different tumors and tumor like lesions at conventional MRI. All the patients underwent conventional MR study and MR perfusion (DSC) examination. 54 lesions were histopathologically proven and matching with the diagnosis, the rest 16 cases were confirmed by clinic-radiologic follow up.