Imaging Brain Tumor: The Implication of Functional Information from MR
Taipei Veterans General Hospital and National Yang-Ming University
Taipei, Taiwan, R.O.C.
Brain tumors, with a variety of histopathlogical origins, behave differently both in clinical course and therapeutic response. The improvement of imaging techniques, mainly advances in tissue characterisation, provides us opportunities to further understand the dilemma in the management of brain tumors. Nowadays, we have a variety imaging accesses to probe brain tumors. To mention some of them: perfusion MR imaging (pMRI), diffusion MR imaging (dMRI), functional MRI (fMRI, BOLD imaging), MR spectroscopic imaging (MRSI), positron emission tomography (PET), magnetic encephalography (MEG), conventional steady state contrast enhanced MR imaging (Gd-MRI) and the integration of them. The advanced imagings provide not only good morphological but also functional, physiological and metabolic information. It plays an important role in multidisciplinary management of brain tumors. Thanks to the continuous integrated endeavors among clinicians, computer scientists and medical engineering, nowadays, integration of the information for clinical application is feasible and possible. Imaging fusion, either using an imager with same geometry or by after-processing, and the implementation of intraoperative MR bring the concept to real. Intraoperative MR system offers unique advantages: 1) continuous access to high resolution, multiplanar MR imaging, 2) an interactive neuronavigational aid, 3) a vitural 3-D visualization tool. For therapy, fast evolving of surgical and non-surgical strategies are encountered. The only one goal of treatment strategy seems to achieve a more effective regimen while keep the therapeutic-relevant invasiveness to a minimum. The role of neuroimaging in the teamwork of brain tumor management remains to define the tumor margins although, for a quite number of them, they are indistinct.