Perfusion-weighted imaging in the assessment of brain gliomas

Because brain gliomas are histologically heterogeneous neoplasms, biopsy targeting must be based on adequate identifi cation of malignant areas on imaging. Considering the reported differences in relative cerebral blood volume (rCBV) among tumor grades, we evaluated whether preoperative perfusion-weighted imaging (PWI) could improve the detection of areas bearing a higher yield for malignancy. We studied a series of 55 consecutive patients with newly diagnosed brain glioma. All patients underwent preoperative MR imaging and PWI. Surgery consisted of stereotactic biopsy in 29 cases and open craniotomy in 24 cases. Patients were followed up to 5 years after the diagnosis to evaluate their fi nal survival. In our experience, PWI added to standard MR imaging improved the choice of targets for biopsy and the diagnostic accuracy, as confi rmed by the clinical follow-up. Despite a less precise demarcation of the tumor borders, it allowed a better localization of its most malignant parts. Among the PWI parameters, we found that only maximal rCBV ratios were clinically useful. PWI was a valuable
implement in the imaging assessment of brain gliomas, discriminating highfrom low-grade tumors. PWI correlated signifi cantly with the tumor grade and the fi nal outcome (P