Blood-oxygen-level-dependent(BOLD) functional MR imaging of brain tumors

There are significant differences between the volumes of activation of BOLD MR signal on the side with the tumor and the contra lateral side. A number of reasons will be considered as the possible. These include: the loss of autoregulation, contribution of the venous component, effect of edema, and the size of the tumor.Several studies show that there is an increase in BOLD signal in the gray matter during hypercapnia. Therefore, BOLD MRI may provide a measure of tumor oxygen tension & tumor hypoxia.BOLD FMRI has many applications in brain tumors imaging . This includes : Identify the anatomy, guide for biopsy, measuring the distance between the brain function and lesion, diffrentiation between gliomas and nonglial space-occupying lesions, monitoring tumor response to radiation , photodynamic therapy and anti angiogenic and antivascular therapy.