Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor Stern Kai 7, 60590, Frankfurt, Germany.
Magnetic Resonance, Siemens AG, Erlangen, Germany.
Radiol Med. 2017 Mar;122(3):194-203. doi: 10.1007/s11547-016-0710-x. Epub 2016 Nov 28.
Purpose of our study was to demonstrate the feasibility and limitations of acoustic noise reduction in a standard clinical MRI protocol for abdominal imaging.
Acoustic noise and image quality were assessed in 17 patients for a standard liver imaging protocol including TSE and GRE sequences and compared to quiet optimizations as described by Heismann et al. Two blinded readers scored artifacts, the delineation of the abdominal organs and level of diagnostic confidence. Means of the sound level measurements, the ratings and the measurement of SNR and CNR were compared.
Significant reduction of acoustic noise was measured for T2 TSE (-30.7%), T2 HASTE (-22.6%) and less difference for T1 DIXON (-4.7%) and T1 FLASH (-2.7%). SNR and CNR were lower for quiet T2 TSE (-18.0%, -23.1%) and T2 HASTE (-46.2%, -37.7%) and higher for T1 DIXON (+32.0%, +24.4%). Inter-rater correlation was k = 0.987 with p < 0.001.
Although sequence-based noise optimizations faces problems in T1 FLASH and DIXON sequences, there is an important acoustic benefit in T2 TSE and T2 HASTE sequences, which goes along with a maintained image quality and diagnostic confidence.
本研究旨在展示在腹部成像的标准临床 MRI 方案中降低噪声的可行性和局限性。
对 17 名患者进行了声学噪声和图像质量评估，该方案包括 TSE 和 GRE 序列，并与 Heismann 等人描述的安静优化进行了比较。两名盲读者对伪影、腹部器官的描绘和诊断信心水平进行了评分。比较了声级测量、评分以及 SNR 和 CNR 的测量结果。
T2 TSE（-30.7%）、T2 HASTE（-22.6%）的噪声显著降低，而 T1 DIXON（-4.7%）和 T1 FLASH（-2.7%）的差异较小。安静 T2 TSE（-18.0%，-23.1%）和 T2 HASTE（-46.2%，-37.7%）的 SNR 和 CNR 较低，而 T1 DIXON（+32.0%，+24.4%）的 SNR 和 CNR 较高。两位评估者之间的相关性为 k=0.987，p<0.001。
尽管基于序列的噪声优化在 T1 FLASH 和 DIXON 序列中存在问题，但 T2 TSE 和 T2 HASTE 序列具有重要的声学优势，同时保持了图像质量和诊断信心。
