Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705-2275, USA.
Magn Reson Med. 2011 Aug;66(2):428-36. doi: 10.1002/mrm.22814. Epub 2011 Feb 28.
For MR applications such as contrast-enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view-sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve on the clinical standard, we present an interleaved variable density (IVD) sampling method that pseudorandomly undersamples each individual frame of a 3D Cartesian ky-kz plane combined with parallel imaging acceleration. From this dataset, time-resolved images are reconstructed with a method that combines parallel imaging with a multiplicative constraint. Total acceleration factors on the order of 20 are achieved for contrast-enhanced MR angiography of the lower extremities, and improvements in temporal fidelity of the depiction of the contrast bolus passage are demonstrated relative to the clinical standard.
对于磁共振（MR）应用，如对比增强磁共振血管造影，同时实现高空间和时间分辨率是理想的。目前的临床标准使用结合并行成像的视图共享方法；然而，这种方法仍然提供有限的空间和时间分辨率。为了提高临床标准，我们提出了一种交错的可变密度（IVD）采样方法，该方法随机对 3D 笛卡尔 ky-kz 平面的每个单独帧进行欠采样，同时结合并行成像加速。从这个数据集，使用结合并行成像和乘法约束的方法重建时分辨图像。对于下肢的对比增强磁共振血管造影，可以实现约 20 的总加速因子，并相对于临床标准证明了对比度团注通过的时间逼真度的提高。
