The role of advanced MR imaging in understanding brain tumour pathology.

Although MRI is the imaging modality of choice for brain tumours, the standard clinical sequences cannot tell us about certain features of brain tumours. Improvements in imaging technology now allow advanced sequences, once used exclusively for research, to be used clinically. Assessment of brain tumours with diffusion weighted MR (a marker of cellularity), diffusion tensor MR (shows integrity of surrounding white matter tracts), perfusion MR (marker of tumour vascularity and angiogenesis), MR spectroscopy (showing tumour metabolism) and functional MR (to identify eloquent cortex) provide information that is complementary to the structural information. These techniques can be used to improve identification of the tumour margin, tumour grading, reducing surgical risk and assessing the response to therapy. It is important for the neurosurgeon to understand what information can be obtained from these sequences, and that they ensure they are used to further develop the assessment and management of brain tumours.