Ferrite-enhanced MRI monitoring in hyperthermia.
In an MRI hyperthermia hybrid system, T1 changes are investigated for monitoring thermal therapy at 0.2 T. The water bolus, which is needed for power transmission and cooling of the skin, limits MR image quality by signal compression and artifacts. Superparamagnetic ferrofluid in different concentration was investigated with MR relaxometry and MRI methods. We found that using ferrofluid in a low concentration of 70-90 ppm magnetite the water signal can be suppressed without susceptibility artifacts. With our method of signal suppression, a significant improvement of spatial and temporal resolution is possible. The ferrofluid is stable and allows RF heating at 100 MHz. This method of signal extinction may also be useful for other experimental setups where suppression of water is necessary.
Reinl
Herbert M
HM
Department of Clinical Radiology, Ludwig-Maximilians-University Munich, Grosshadern, D-81377 Munich, Germany. hreinl@med.uni-muenchen.de
Peller
Michael
M
Hagmann
Mark
M
Turner
Paul
P
Issels
Rolf D
RD
Reiser
Maximilian
M
D016477:Artifacts; D003287:Contrast Media; D005290:Ferric Compounds; D006979:Hyperthermia, Induced; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009369:Neoplasms / Q000628:therapy; D019047:Phantoms, Imaging
D003287:Contrast Media; D005290:Ferric Compounds; C001215:ferrite