Benkert Thomas, Bartsch Andreas J, Blaimer Martin, Jakob Peter M, Breuer Felix A
Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.
Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany.
Magn Reson Med. 2015 Jun;73(6):2129-41. doi: 10.1002/mrm.25337. Epub 2014 Jun 27.
Recently, the (Resolution Enhanced-) T1 insensitive steady-state imaging (TOSSI) approach has been proposed for the fast acquisition of T2 -weighted images. This has been achieved by balanced steady-state free precession (bSSFP) imaging between unequally spaced inversion pulses. The purpose of this work is to present an extension of this technique, considerably increasing both the efficiency and possibilities of TOSSI.
A radial trajectory in combination with an appropriate view-sharing reconstruction is used. Because each projection traverses the contrast defining k-space center, several different contrasts can be extracted from a single-shot measurement. These contrasts include various T2 -weightings and T2 /T1 -weighting if an even number of inversion pulses is used, while an odd number allow the generation of several images with predefined tissue types cancelled.
The approach is validated for brain and abdominal imaging at 3.0 Tesla. Results are compared with RE-TOSSI, bSSFP, and turbo spin-echo images and are shown to provide similar contrasts in a fraction of scan time. Furthermore, the potential utility of the approach is illustrated by images obtained from a brain tumor patient.
Radial T1 sensitive and insensitive steady-state imaging is able to generate multiple contrasts out of one single-shot measurement in a short scan time.
最近,有人提出了(分辨率增强型)T1不敏感稳态成像(TOSSI)方法,用于快速采集T2加权图像。这是通过在不等间距反转脉冲之间进行平衡稳态自由进动(bSSFP)成像实现的。这项工作的目的是介绍该技术的一种扩展,显著提高TOSSI的效率和可能性。
使用径向轨迹结合适当的视图共享重建。由于每个投影都穿过对比度定义的k空间中心,因此可以从单次测量中提取几种不同的对比度。如果使用偶数个反转脉冲,这些对比度包括各种T2加权和T2/T1加权,而奇数个反转脉冲则允许生成几个消除了预定义组织类型的图像。
该方法在3.0特斯拉下对脑部和腹部成像进行了验证。将结果与分辨率增强型TOSSI、bSSFP和快速自旋回波图像进行了比较,结果表明在扫描时间的一小部分内提供了相似的对比度。此外,通过从一名脑肿瘤患者获得的图像说明了该方法的潜在效用。
径向T1敏感和不敏感稳态成像能够在短扫描时间内从单次测量中生成多种对比度。