Patients receive efaproxiral and carmustine on clinical trial NABTT-9806. During any one course of treatment on that study, patients undergo MRI before oxygen administration (baseline), before efaproxiral infusion, and then every 5 minutes until 1 hour after efaproxiral and carmustine treatment. Data is evaluated for extent and intensity of T2/T2* changes and oxygen concentration changes in both abnormal and normal brain.