Heismann Björn, Ott Martin, Grodzki David
Siemens Healthcare, Magnetic Resonance Imaging, Erlangen, Germany; Friedrich-Alexander-University of Erlangen-Nuremberg, Pattern Recognition Lab, Erlangen, Germany.
Magn Reson Med. 2015 Mar;73(3):1104-9. doi: 10.1002/mrm.25229. Epub 2014 May 29.
Clinical MRI patients typically experience elevated acoustic noise levels of 80-110 dB(A). In this study, standard clinical turbo spin echo (TSE) and gradient echo (GRE) sequences were optimized for reduced acoustic noise at preserved diagnostic image quality.
The physical sources of acoustic noise generation in an MRI gradient coil were analyzed. A sequence conversion algorithm was derived that optimized the gradient time scheme for an arbitrary MRI sequence, preserving the governing spin physics. The algorithm was applied to generate "quiet" versions of standard clinical TSE and GRE sequences.
The first volunteer images indicated that contrast-to-noise ratio and perceived diagnostic image quality remained on the same level for the algorithmic optimization. Additional careful TSE- and GRE-specific protocol adaptions yielded total acoustic noise reductions of up to 14.4 dB(A) for the TSE and up to 16.8 dB(A) for the GRE.
A physical sound pressure reduction of 81% (TSE) and 86% (GRE) for MRI patients was achieved. The results can be used to render MRI scans more patient-friendly in clinical practice, particularly for patients who are young, scared, or elderly.
临床MRI患者通常会经历80 - 110 dB(A)的较高噪声水平。在本研究中,对标准临床快速自旋回波(TSE)和梯度回波(GRE)序列进行了优化,以在保持诊断图像质量的同时降低噪声。
分析了MRI梯度线圈中产生噪声的物理来源。推导了一种序列转换算法,该算法针对任意MRI序列优化梯度时间方案,同时保留主导的自旋物理特性。应用该算法生成标准临床TSE和GRE序列的“安静”版本。
首批志愿者图像表明,算法优化后对比度噪声比和感知诊断图像质量保持在同一水平。对TSE和GRE进行额外仔细的特定协议调整后,TSE的总噪声降低高达14.4 dB(A),GRE的总噪声降低高达16.8 dB(A)。
为MRI患者实现了81%(TSE)和86%(GRE)的物理声压降低。该结果可用于在临床实践中使MRI扫描对患者更友好,特别是对于年轻、恐惧或年长的患者。