An implementation of Non‐Fourier chirp‐encoding in 3D Gradient Recalled Echo (GRE), susceptibility‐weighted imaging (SWI) and Magnetization Prepared Rapid Gradient Echo (MPRAGE) sequences is presented with compressive sensing reconstruction. 3D GRE and MPRAGE sequences were designed, in which the phase encoding (PE) direction was encoded with spatially selective chirp encoding Radio Frequency (RF) pulses, while the slice and the readout directions were Fourier encoded using gradients. During each excitation along the PE direction, a different spatially‐selective RF excitation pulse was used to encode the PE direction with a complete set of unitary chirp encoding basis. Multichannel compressive sensing reconstruction on the undersampled in vivo data demonstrated that images reconstructed from chirp encoded data were able to preserve the spatial resolution better than the Fourier encoding. The mean Structural Similarity (SSIM) across five subjects at the acceleration factor of 6, for chirp encoded MPRAGE was 0.934 compared to 0.912 for Fourier encoded MPRAGE. The implementation of prospective undersampling demonstrated the feasibility of using chirp encoding in clinical practice for accelerated imaging. The minimum intensity projection of the compressive sensing (CS) reconstructed susceptibility weighted images revealed that chirp encoding is able to delineate small vessels better than the Fourier encoding with the SSIM of 0.960 for chirp encoding compared to the SSIM of 0.949 for the Fourier encoding. Improved performance of chirp encoding for CS reconstruction and SWI, along with the feasibility of implementation makes them a practical candidate for clinical MRI scans.

中文翻译：

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使用线性调频编码的3D GRE和MPRAGE序列进行压缩感测的应用

通过压缩感测重建，提出了在3D梯度回波（GRE），磁化加权成像（SWI）和磁化快速梯度回波（MPRAGE）序列中实现非傅立叶线性调频编码的方法。设计了3D GRE和MPRAGE序列，其中使用空间选择性线性调频编码射频（RF）脉冲对相位编码（PE）方向进行编码，而使用梯度对条带和读出方向进行傅立叶编码。在沿PE方向的每次激励过程中，使用不同的空间选择性RF激励脉冲以完整的of线性编码基础集对PE方向进行编码。对欠采样的体内数据的多通道压缩感测重建表明，从chi编码数据重建的图像比傅立叶编码能够更好地保留空间分辨率。线性调频编码MPRAGE的加速因子为6时，五个对象的平均结构相似度（SSIM）为0.934，而傅立叶编码MPRAGE的平均结构相似度为0.912。前瞻性欠采样的实施证明了在临床实践中使用线性调频编码进行加速成像的可行性。压缩感测（CS）重建磁化率加权图像的最小强度投影显示，线性调频编码比线性傅立叶编码能够更好地描绘小血管，线性调频编码的SSIM为0.960，而傅立叶编码的SSIM为0.949。