Melki P S, Mulkern R V, Panych L P, Jolesz F A
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115.
J Magn Reson Imaging. 1991 May-Jun;1(3):319-26. doi: 10.1002/jmri.1880010310.
The FAISE (fast-acquisition interleaved spin-echo) technique consists of a hybrid rapid-acquisition relaxation-enhanced (RARE) sequence combined with a specific phase-encode reordering method. Implemented on a 1.5-T unit, this multisection, high-resolution technique permits convenient contrast manipulation similar to that of spin-echo imaging, with selection of a pseudo-echo-time parameter and a TR interval. With a TR of 2 seconds, eight 256 x 256 images are obtained in 34 seconds with either T2 or proton-density weighting. A direct comparison between FAISE and spin echo for obtaining T2-weighted head images in healthy subjects indicates that FAISE and spin-echo images are qualitatively and quantitatively similar. Image artifacts are more pronounced on "proton-density" FAISE images than on the T2-weighted FAISE images. T1 contrast can be obtained with inversion recovery and short TR FAISE images. Preliminary temperature measurements in saline phantoms do not indicate excessive temperature increases with extended FAISE acquisitions. However, extensive studies of radio-frequency power deposition effects should be performed if the FAISE technique is to be fully exploited.
FAISE（快速采集交错自旋回波）技术由一种混合的快速采集弛豫增强（RARE）序列与特定的相位编码重排序方法组成。在1.5-T设备上实施时，这种多层面、高分辨率技术允许进行类似于自旋回波成像的便捷对比操作，可选择伪回波时间参数和TR间期。当TR为2秒时，采用T2加权或质子密度加权，在34秒内可获得8幅256×256图像。对健康受试者获取T2加权头部图像时FAISE与自旋回波的直接比较表明，FAISE图像和自旋回波图像在质量和数量上相似。图像伪影在“质子密度”FAISE图像上比在T2加权FAISE图像上更明显。通过反转恢复和短TR FAISE图像可获得T1对比。在盐水体模中的初步温度测量未显示长时间FAISE采集会导致温度过度升高。然而，如果要充分利用FAISE技术，应进行关于射频功率沉积效应的广泛研究。
