issur for fat sat-GE磁共振.pptVIP

GE Medical Systems – fat sat http://guest:guest@86/websupport/clearexp_cgi/fts1.htm Description: Solution: GE Medical Systems P r e s e n t s Discussion about fat sat Increase contrast Differentiate the pathological origin Magnet homogenity superior software design High SNR Fat sat image merits Technical basis Focal nodular hyperplasia FRFSE T2, fat sat, respiratory trigger FRFSE T2, respiratory trigger 2D Fiesta frequency 220 Hz 1.5 T water fat fat selective bandwidth 100Hz Fat sat profile If water is off center about 40Hz, fat cann’t been suppressed First doing Auto Prescan Select Manual Prescan, CFA FINE. Center the water peak Adjust “cstun”, which means turning on the fat sat pulse in Prescan, the operator can see the sat result While observing fat peak, adjust “csa”, which means adjusting the fat sat pulse amplitude While observing fat peak, adjust “csf”, which means adjusting the fat and water’s “chemical shift frequency” difference. Save these frequency Done and scan Basic method for chemical fat suppression scan If water peak is off centered too far away, do the steps as follows Put fat peak on the center vertical line press the command “dx200” Adjust “cstun” as usually we do Basic method for chemical fat suppression scan Specific method for chemical fat suppression scan For LX, Extremity coil While adjusting “csa”, the final result should add 20 Specific method for chemical fat suppression scan For T2WI scan, we can press the PSD name “fse-xlc or frfse-xlc” More uniform fat sat The image will be a little bright than without this PSD name Clinical application cases While doing fat sat scan, it says file ecccoeff.dat on /usr/g/caldir had been corrupted restore info or do Eddy Currents adjustment Fat sat doesn’t work when scaning extremity or breast Because these are off-center position, there are limitations in obtaining a homogeneous magnetic field over a large area. Reduce FOV less than 20cm For Shoulder coil, system do