Edelman R R, Atkinson D J, Silver M S, Loaiza F L, Warren W S
Department of Radiology, Grossmont Hospital, La Mesa, CA 92041.
Radiology. 1988 Jan;166(1 Pt 1):231-6. doi: 10.1148/radiology.166.1.3336685.
Magnetic resonance images of the spine, chest, abdomen, and pelvis are commonly degraded by ghost artifacts. The authors have developed a new technique named FRODO (Flow and Respiratory artifact Obliteration with Directed Orthogonal pulses) to suppress these artifacts. Signal from tissues responsible for the artifacts is eliminated by use of radio frequency pulses specifically optimized for high selectivity to saturate proton magnetization over one or more independently defined slabs (large rectangular volumes) of tissue. Ghost artifacts from pulsatile flow in the heart and blood vessels, as well as from respiratory motion and swallowing, are suppressed. Additional applications of this technique include elimination of intraluminal signal in blood vessels and suppression of wraparound artifact along the phase-encoding axis. Preliminary clinical experience suggests that the FRODO technique, in conjunction with other flow compensation methods, may provide a definitive solution to the problem of motion in spine imaging. FRODO pulse sequences may also prove useful for imaging of blood vessels, heart, abdomen, and other areas where motion, flow, or wraparound artifacts limit image quality.
脊柱、胸部、腹部和骨盆的磁共振图像通常会受到鬼影伪影的影响而质量下降。作者开发了一种名为FRODO（利用定向正交脉冲消除血流和呼吸伪影）的新技术来抑制这些伪影。通过使用专门优化的具有高选择性的射频脉冲，使质子磁化在一个或多个独立定义的组织层块（大的矩形体积）上饱和，从而消除产生伪影的组织信号。心脏和血管中搏动血流以及呼吸运动和吞咽产生的鬼影伪影都得到了抑制。该技术的其他应用包括消除血管腔内信号以及抑制沿相位编码轴的卷褶伪影。初步临床经验表明，FRODO技术与其他血流补偿方法相结合，可能为脊柱成像中的运动问题提供一个明确的解决方案。FRODO脉冲序列对于血管、心脏、腹部以及其他因运动、血流或卷褶伪影而限制图像质量的区域的成像也可能很有用。
