Atsushi Mark Takahashi - Menlo Park CA, US Richard Scott Hinks - Waukesha WI, US
Assignee:
General Electric Company - Schenectady NY
International Classification:
G01V 3/00
US Classification:
324309, 324307
Abstract:
A pulse sequence is defined to acquire calibration MR data used to characterize on-axis and cross-axis eddy currents resulting from gradient pulses used to spatially encode MR data. The amplitudes and time constants of those eddy currents can then be measured and used to guide calibration of an MRI system to reduce image artifacts.
Reduction Of Slice Select Artifacts In Half Pulse Excitations Used In Ultrashort Te (Ute) Imaging
The present embodiments are directed towards artifact reduction in slice select pulse sequences utilized in ultra short echo time imaging sequences. In one embodiment, a method includes determining a desired slice select thickness, determining a radiofrequency pulse shape and duration based upon the desired slice select thickness while maintaining a desired relationship between excitation k space and radiofrequency amplitude, and determining radiofrequency scaling based on the determined radiofrequency pulse shape and duration.
The ships refused to leave, saying the area was Chinese territory, according to Atsushi Takahashi, a spokesman for the Coast Guard's headquarters in Okinawa, which has jurisdiction over the islands. He said it was the first time Chinese ships had entered the territorial waters since Oct. 3.