Flow imaging using balanced phase contrast steady

专利名称：Flow imaging using balanced phase contrast

steady state free precession magneticresonance imaging

发明人：Michael Markl,Norbert J. Pelc,Marcus Alley申请号：US10317463申请日：20021211

公开号：US20040113613A1公开日：20040617

专利附图：

摘要：A novel technique for velocity measurements (PC-SSFP) is disclosed thatcombines CINE Phase Contrast (PC) MRI and balanced Steady State Free Precession

(SSFP) imaging. Flow encoding is performed without the introduction of additionalvelocity encoding gradients in order to permit data acquisition with short TR comparableto repetition times of typical SSFP imaging sequences. Sensitivity to through planevelocities is instead established by inverting (i.e. negating) all gradients along the sliceselect direction. Velocity sensitivity (venc) can be adjusted by altering the first momentsof the slice select gradients. Disturbances of the SSFP steady state are avoided byacquiring different flow echoes in consecutively (i.e. sequentially) executed scans, eachover several cardiac cycles, using separate steady state preparation periods. Comparisonof phantom measurements with those from established 2D-CINE-PC MRI excellentcorrelation between both modalities. Results of volunteer examinations exhibitadvantages of PC-SSFP, which include the intrinsic high signal to noise ratio (SNR) ofbalanced SSFP and consequently low phase noise in measured velocities. An additionalbenefit of PC-SSFP is its lower reliance on in-flow dependent signal enhancement,therefore yielding more uniform SNR and better depiction of vessel geometrythroughout the whole cardiac cycle in structures with slow and/or pulsatile flow.

申请人：THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY

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