The Role of MRI tractography in the Preoperative Assessment of Brain Tumors

Abstract

Before proper planning of brain surgery, it is very important to avoid injury of the key functional regions of the brain .Neurosurgery is a trade-off between maximum surgical resection on one hand and maximum sparing of functions on the other hand. Extensive tumor resection can reduce the risk of relapse and allow subsequent radiotherapy or chemotherapy to be more effective. On the other hand, sparing “functionally relevant” zones significantly improves the quality of life of these patients . We have a fair amount of knowledge about functional maps of the cortex, but we do not have equivalent maps of the white matter. The location and functions of the cortex can be deduced from the folding patterns of the cortex but the white matter appears as just a homogenous structure during surgery. Even if we avoid injury to an important cortical area, the patient could lose function if the white matter tract responsible for the function is cut. Therefore, the identification of motor, language, auditory, and visual pathways is very important for brain surgery. For realizing these goals, many imaging modalities were used to assess brain tumors, which include conventional MRI and MR spectroscopy, Positron Emission Tomography and functional MRI. Magnetic resonance (MR) imaging plays an important role in the detection and evaluation of brain tumors. a number of advanced MR imaging techniques have been developed that provide new methods for the assessment of brain tumors. One of these techniques is diffusion tensor imaging (DTI)