Corcuera-Solano I, Doshi A, Pawha P S, Gui D, Gaddipati A, Tanenbaum L
From the Neuroradiology Section, Department of Radiology (I.C.-S., A.D., P.S.P., L.T.), Icahn School of Medicine at Mount Sinai Hospital, Radiology, New York, New York.
GE Healthcare (D.G., A.G.), Milwaukee, Wisconsin.
AJNR Am J Neuroradiol. 2015 Jun;36(6):1124-7. doi: 10.3174/ajnr.A4235. Epub 2015 Feb 12.
Switching of magnetic field gradients is the primary source of acoustic noise in MR imaging. Sound pressure levels can run as high as 120 dB, capable of producing physical discomfort and at least temporary hearing loss, mandating hearing protection. New technology has made quieter techniques feasible, which range from as low as 80 dB to nearly silent. The purpose of this study was to evaluate the image quality of new commercially available quiet T2 and quiet FLAIR fast spin-echo PROPELLER acquisitions in comparison with equivalent conventional PROPELLER techniques in current day-to-day practice in imaging of the brain.
Thirty-four consecutive patients were prospectively scanned with quiet T2 and quiet T2 FLAIR PROPELLER, in addition to spatial resolution-matched conventional T2 and T2 FLAIR PROPELLER imaging sequences on a clinical 1.5T MR imaging scanner. Measurement of sound pressure levels and qualitative evaluation of relative image quality was performed.
Quiet T2 and quiet T2 FLAIR were comparable in image quality with conventional acquisitions, with sound levels of approximately 75 dB, a reduction in average sound pressure levels of up to 28.5 dB, with no significant trade-offs aside from longer scan times.
Quiet FSE provides equivalent image quality at comfortable sound pressure levels at the cost of slightly longer scan times. The significant reduction in potentially injurious noise is particularly important in vulnerable populations such as children, the elderly, and the debilitated. Quiet techniques should be considered in these special situations for routine use in clinical practice.
磁场梯度切换是磁共振成像中声学噪声的主要来源。声压水平可高达120分贝，能够产生身体不适并至少导致暂时性听力损失，因此需要听力保护。新技术已使更安静的技术成为可能，其声压水平低至80分贝甚至几乎无声。本研究的目的是在当前大脑成像的日常实践中，将新的商用安静T2和安静液体衰减反转恢复（FLAIR）快速自旋回波螺旋桨采集的图像质量与等效的传统螺旋桨技术进行比较。
除了在临床1.5T磁共振成像扫描仪上对34例连续患者进行空间分辨率匹配的传统T2和T2 FLAIR螺旋桨成像序列扫描外，还前瞻性地对他们进行了安静T2和安静T2 FLAIR螺旋桨扫描。进行了声压水平测量和相对图像质量的定性评估。
安静T2和安静T2 FLAIR的图像质量与传统采集相当，声级约为75分贝，平均声压水平降低高达28.5分贝，除了扫描时间较长外没有显著的权衡。
安静快速自旋回波（FSE）以略长的扫描时间为代价，在舒适的声压水平下提供了等效的图像质量。在儿童、老年人和体弱患者等弱势群体中，潜在有害噪声的显著降低尤为重要。在这些特殊情况下，临床实践中应考虑常规使用安静技术。
