Spin-lattice relaxation and magnetization transfer in intracranial tumors in vivo: effects of Gd-DTPA on relaxation parameters.
Spin-lattice relaxation time T1 and relaxation parameters in magnetization transfer (MT) imaging were measured in 11 intracranial tumors before and after injection of Gd-DTPA at 0.1 T by using the inversion recovery method and the saturation transfer technique, respectively. Preinjection T1 relaxation times of the tumors were longer than those of white matter, but after Gd-enhancement the relaxation times of most tumors were in the same range as those of white matter. Gd-DTPA shortened the apparent relaxation time in the presence of off-resonance saturation pulse (T1a) due to marked shortening of the relaxation time of mobile water (T1w). Gd-DTPA decreased the magnetization transfer contrast (MTC) but did not influence on the magnetization transfer rate (Rwm). The parameters MTC and Rwm differed clearly between Gd-enhanced tumors and normal brain, whereas the relaxation time T1a was in many Gd-enhanced tumors in the same range as in normal brain.
Kurki
T
T
Department of Diagnostic Radiology, Turku University Hospital, Finland.
Komu
M
M
D001932:Brain Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D019786:Gadolinium DTPA; D005909:Glioblastoma / Q000175:diagnosis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008579:Meningioma / Q000175:diagnosis; D009464:Neuroma, Acoustic / Q000175:diagnosis; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives*
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D019786:Gadolinium DTPA