DYNAMIC STUDIES OF GADOLINIUM UPTAKE IN BRAIN-TUMORS USING INVERSION-RECOVERY ECHO-PLANAR IMAGING

Echo‐planar imaging has been used to observe the dynamics of Gd‐DTPA uptake in brain tumors. It has been possible to examine both vascular uptake and diffusion across the blood‐brain barrier in a single experiment, by using the IR‐MBEST echo‐planar sequence which combines a high temporal resolution (approximately 3 s) with strong T1 weighting. To model the uptake it is necessary to know the arterial concentration of Gd‐DTPA; in this study the signal in the sagittal sinus was measured to avoid the need to take repeated blood samples. The time constant for transfer across the blood‐brain barrier was measured to be between 20 and 1050 s for different tumors. The results of the modeling correlated with the results of other assessments of tumor vascularity. Copyright © 1992 Wiley‐Liss, Inc., A Wiley Company