Time-dependent changes in image contrast in brain tumors after XXXX .

@entity1 @entity39 @entity5 @entity4 @entity7241
Time-dependent changes in the contrast enhancement of @entity5 tissue, @entity5 @entity39 , perifocal @entity4 , and normal brain tissue after IV injection of 0.1 mmol @entity7241 /kg body weight were studied with spin-echo technique (SE 800/35) in 15 @entity1 with @entity5 . Using a region of interest technique, we determined the signal-intensity values of these tissues before and at fixed times up to 68.5 min after administration of the contrast agent. In @entity5 tissue, the 8.5 min postinjection (p.i.) scan showed a significant increase in signal intensity. The signal intensity of the @entity5 tissue remained significantly higher than precontrast levels throughout the entire period of observation, decreasing only slightly toward the end of the examination (48.5 and 68.5 min p.i.). Central @entity5 @entity39 exhibited a delayed uptake of the contrast agent, with a maximum signal intensity between 48.5 and 68.5 min p.i. In perifocal @entity4 and normal brain tissue, slight increases in signal intensity after injection of @entity7241 were measured (statistically significant in the case of @entity4 ). This effect, however, was not visually detectable. The present study shows that after one injection, scans with excellent @entity5 visualization can be obtained between 8.5 and 38.5 min p.i. and with diagnostically valid enhancement at least up to 68.5 min p.i.
