Huo Zimu, de Arcos José, Wiesinger Florian, Kaggie Joshua D, Graves Martin J
Department of Radiology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.
GE HealthCare, Amersham, UK.
Magn Reson Med. 2025 Mar;93(3):1149-1162. doi: 10.1002/mrm.30345. Epub 2024 Nov 4.
A new referenceless low-rank reconstruction technique has been introduced to address the issue of missing samples within the Zero Echo Time (ZTE) dead-time gap.
The proposed method reformulates the in-filling of the missing samples as an inverse problem subject to low-rank constraints. Its performance and robustness are evaluated through a comparative analysis that combines Monte Carlo computational simulations and data obtained from in vivo experiments.
The proposed method is tested for dead-time gaps ranging up to 4.5 Nyquist dwells, across signal-to-noise ratio levels of 5, 10, 15, and 20 dB. Consistently superior performance is observed across all cases compared to algebraic and parallel imaging methods. The speed for convergence decreases exponentially as the dead-time gap expands.
The proposed method enables artifact-free reconstruction up to dead-time gap of 4 Nyquist dwells and thereby supports ZTE imaging up to an imaging bandwidth of kHz (assuming transmit and receive switching less than 30 s). It demonstrates superior performance compared to algebraic and parallel imaging methods.
引入一种新的无参考低秩重建技术，以解决零回波时间（ZTE）死时间间隙内样本缺失的问题。
所提出的方法将缺失样本的填充重新表述为一个受低秩约束的反问题。通过结合蒙特卡罗计算模拟和体内实验获得的数据进行对比分析，评估其性能和鲁棒性。
所提出的方法针对高达4.5奈奎斯特驻留时间的死时间间隙进行了测试，涵盖了5、10、15和20 dB的信噪比水平。与代数和并行成像方法相比，在所有情况下均观察到一致的卓越性能。随着死时间间隙的扩大，收敛速度呈指数下降。
所提出的方法能够实现高达4奈奎斯特驻留时间的死时间间隙的无伪影重建，从而支持高达kHz成像带宽的ZTE成像（假设发射和接收切换小于30 s）。与代数和并行成像方法相比，它表现出卓越的性能。
