13-06-2013 дата публикации
Номер: US20130147478A1
Принадлежит:
A GRASE-type PROPELLER sequence called Steer-PROP is disclosed. This sequence exploits a serious of steer blips together with rewinding gradient pulse to traverse k-space. Steer-PROP improves the scan time by a factor of 3 or higher compared to FSE-PROPELLER, provides improved robustness to off-resonance effects compared to EPI-PROPELLER, and addresses a long-standing phase correction problem inherent to GRASE based sequences. Steer-PROP also enables intra-blade, inter-blade, and inter-shot phase errors to be separately determined and independently corrected. 1. In a magnetic resonance imaging (MRI) system , a computer-implemented method comprising:applying to an object in the MRI system a first radio frequency (RF) pulse and, after a first fast spin echo (FSE) inter-echo time interval, applying to the object a second RF pulse;{'sub': x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x, 'applying to the object during the first FSE inter-echo time interval between the first and second RF pulses a first magnetic field gradient (G) pulse train along a first direction, the first Gpulse train comprising an integer number M adjacent Gpulses, each consecutive pair of Gpulses of the first Gpulse train being separated by a Gsteering pulse, and the last Gpulse of the first Gpulse train being followed by a first Grewinding pulse;'}{'sub': x', 'y', 'y', 'y', 'y', 'y', 'x', 'y', 'x', 'x', 'y', 'y', 'y', 'x', 'y', 'x', 'x', 'y', 'y', 'y', 'x', 'y', 'x', 'x, 'applying to the object simultaneously with the first Gpulse train a first magnetic field gradient (G) pulse train along a second direction, the first Gpulse train comprising M adjacent Gpulses, each Gpulse of the first Gpulse train forming a respective first-train G-Gpulse pair with a simultaneous corresponding Gpulse of the first Gpulse train, each consecutive pair of Gpulses of the first Gpulse train being separated by a Gsteering pulse that forms a respective first-train G-Gsteering-pulse pair with a simultaneous corresponding ...
Подробнее
