OUTLINE: Patients undergo perfusion magnetic resonance imaging (MRI) scanning with contrast in conjunction with preoperative conventional MRI scanning with contrast. Patients receive gadopentetate dimeglumine IV over 5 seconds prior to perfusion MRI. Gadopentetate dimeglumine is administered at a slower rate prior to conventional MRI. Patients undergo blood draw to determine urokinase type plasminogen activator levels. After completion of perfusion and conventional MRI scanning, brain tumor tissue samples are obtained during surgical resection to determine tumor grade and type and urokinase type plasminogen activator and basic fibroblast growth factor levels. If CSF removal is required during surgery, then CSF samples are collected to determine urokinase type plasminogen activator and basic fibroblast growth factor levels.