الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Brain tumor surgery involves an equilibrium between maximum surgical resection and maximum sparing of functions. On one hand, gross total tumoral resection decreases the risk of relapse and allows for subsequent radiotherapy or chemotherapy to be more effective. On the other hand, sparing functionally relevant areas and, therefore, preservation of motor, language, or visual functions significantly improves the quality of life of patients. The location and functions of cortex can be deduced from the folding patterns of the cortex or by various modalities described earlier but the WM appears as just a homogenous structure during surgery. Even if injury to an important cortical area is avoided, the patient could lose function if the WM tracts responsible for the function are injured. Therefore, the identification of WM tracts is important. In DTI, WM tracts may be pathologically altered by tumors in several ways. They may be displaced, infiltrated, or destroyed by tumors. Our study is unique in describing the role of preoperative and postoperative DTI in brain tumors. We studied 20 patients, 14 males (70%) and 6 females (30%), ages ranging from 20 to 55 years with different types of brain tumors (ranging from low grade to high grade). The altered states of WM in the vicinity of cerebral neoplasm influence the measurement of diffusion tensor anisotropy and orientation in various ways, resulting in several patterns on directional DTI color maps. In our study, as in previous studies, we classified the WM tract involvement as displaced, infiltrated, and disrupted based on orientation of fibers and their FA values. We compared the preoperative and post-operative WMT in each pattern. The most common pattern of affection detected in our study is the displacement pattern being detected in both low and high grade group. In our study destruction pattern was totally confined to the high grade lesions. Edema pattern and partial disruption pattern are more prevalent in the high grade lesions. After surgical resection, most low grades lesions showed normalization of the tracts while normalization of position and partial FA improvement occurred at both high and to less extent low grades lesions while no fiber tract position or FA improvement was confined to high grade lesions.