Willinek Winfried A, Hadizadeh Dariusch R, von Falkenhausen Marcus, Urbach Horst, Hoogeveen R, Schild Hans H, Gieseke Jürgen
Department of Radiology, University of Bonn, Bonn, Germany.
J Magn Reson Imaging. 2008 Jun;27(6):1455-60. doi: 10.1002/jmri.21354.
To present a new 4D method that is designed to provide high spatial resolution MR angiograms at subsecond temporal resolution by combining different techniques of view sharing with parallel imaging at 3.0T.
In the keyhole-based method, a central elliptical cylinder in k-space is repeated n times (keyhole) with a random acquisition (CENTRA), and followed by the readout of the periphery of k-space. 4D-MR angiography with CENTRA keyhole (4D-TRAK) was combined with parallel imaging (SENSE) and partial Fourier imaging. In total, a speed-up factor of 66.5 (6.25 [CENTRA keyhole] x 8 [SENSE] x 1.33 [partial Fourier imaging]) was achieved yielding a temporal resolution of 608 ms and a spatial resolution of (1.1 x 1.4 x 1.1) mm(3) with whole-brain coverage 4D-TRAK was applied to five patients and compared with digital subtraction angiography (DSA).
4D-TRAK was successfully completed with an acceleration factor of 66.5 in all five patients. Sharp images were acquired without any artifacts possibly created by the transition of the central cylinder and the reference dataset. MRA findings were concordant with DSA.
4D time-resolved MRA with keyhole (4D-TRAK) is feasible using a combination of CENTRA, keyhole, and SENSE at 3.0T and allows for more than 60 times accelerated MRA with high spatial resolution.
介绍一种新的4D方法，该方法旨在通过在3.0T条件下将不同的视图共享技术与并行成像相结合，以亚秒级的时间分辨率提供高空间分辨率的磁共振血管造影。
在基于钥匙孔的方法中，k空间中的中心椭圆圆柱体（钥匙孔）以随机采集（CENTRA）的方式重复n次，然后读取k空间的周边。将带有CENTRA钥匙孔的4D磁共振血管造影（4D-TRAK）与并行成像（SENSE）和部分傅里叶成像相结合。总共实现了66.5的加速因子（6.25 [CENTRA钥匙孔]×8 [SENSE]×1.33 [部分傅里叶成像]），时间分辨率为608毫秒，空间分辨率为(1.1×1.4×1.1)立方毫米，实现全脑覆盖。4D-TRAK应用于5名患者，并与数字减影血管造影（DSA）进行比较。
所有5名患者均成功完成了加速因子为66.5的4D-TRAK。采集到的图像清晰，没有因中心圆柱体和参考数据集的转换而可能产生的任何伪影。磁共振血管造影结果与DSA一致。
在3.0T条件下，结合CENTRA、钥匙孔和SENSE的基于钥匙孔的4D时间分辨磁共振血管造影（4D-TRAK）是可行的，并且可以实现超过60倍加速的高空间分辨率磁共振血管造影。
