Division of Applied Mechanics, Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, Maryland, USA.
Division of Biomedical Physics, Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, Maryland, USA.
J Magn Reson Imaging. 2021 Oct;54(4):1119-1125. doi: 10.1002/jmri.27656. Epub 2021 May 4.
Auditory and non-auditory safety concerns associated with the appreciable sound levels inherent to magnetic resonance imaging (MRI) procedures exist for neonates. However, current gaps in knowledge preclude making an adequate risk assessment.
To measure acoustic exposure (duration, intensity, and frequency) during neonatal brain MRI and compare these values to existing hearing safety limits and data.
Phantom.
Cylindrical doped water phantom.
FIELD STRENGTH/SEQUENCE: Neonatal brain protocols acquired at 1-3 T. Scans in the model protocol included a diffusion tensor imaging scan, a gradient echo, a three-dimensional (3D) fast spin echo, 3D fast spin-echo single-shots, a spin echo, a turbo spin echo, a 3D arterial spin labeling scan, and a susceptibility-weighted fast spin-echo scan.
The sound pressure levels (SPLs), frequency profile, and durations of five neonatal brain protocols on five MR scanners (scanner A [3 T, whole-body], scanner B [1.5 T, whole-body], scanner C [1 T, dedicated neonatal], scanner D [1.5 T, whole-body], and scanner E [3 T, whole-body]) located at three different sites were recorded. The SPLs were then compared to the International Electrotechnical Commission (IEC) hearing safety limit and existing data of infant non-auditory responses to loud sounds to assess risk.
Mann-Whitney U test to assess whether the dedicated neonatal scanner was quieter than the other machines.
The average level A-weighted equivalent value (LAEQ) across all five MR scanners and scans was 92.88 dBA and the range of LAEQs across all five MR scanners and scans was 80.8-105.31 dBA. The duration of the recorded neonatal protocols maintained by neonatal scanning facilities (from scanners A, B, and C) ranged from 27:33 to 37:06 minutes.
Neonatal protocol sound levels straddled existing notions of risk, exceeding sound levels known to cause non-auditory responses in neonates but not exceeding the IEC MRI SPL safety limit.
5 TECHNICAL EFFICACY: Stage 5.
由于磁共振成像（MRI）程序固有的可观声级，与新生儿相关的听觉和非听觉安全问题仍然存在。然而，目前知识上的差距使得对风险进行充分评估变得困难。
测量新生儿脑 MRI 期间的声暴露（持续时间、强度和频率），并将这些值与现有的听力安全限值和数据进行比较。
体模。
圆柱形掺杂水模体。
场强/序列：在 1-3 T 处采集新生儿脑协议。模型协议中的扫描包括弥散张量成像扫描、梯度回波、三维（3D）快速自旋回波、3D 快速自旋回波单次拍摄、自旋回波、涡轮自旋回波、3D 动脉自旋标记扫描和磁化率加权快速自旋回波扫描。
记录了位于三个不同地点的五台 MRI 扫描仪（扫描仪 A [3 T，全身]、扫描仪 B [1.5 T，全身]、扫描仪 C [1 T，专用新生儿]、扫描仪 D [1.5 T，全身]和扫描仪 E [3 T，全身]）上的五个新生儿脑协议的声压级（SPL）、频率分布和持续时间。然后将 SPL 与国际电工委员会（IEC）听力安全限值和现有婴儿对大声响的非听觉反应数据进行比较，以评估风险。
使用曼-惠特尼 U 检验评估专用新生儿扫描仪是否比其他机器更安静。
所有五台 MRI 扫描仪和扫描的平均 A 加权等效值（LAEQ）为 92.88 dBA，所有五台 MRI 扫描仪和扫描的 LAEQ 范围为 80.8-105.31 dBA。新生儿扫描设施（来自扫描仪 A、B 和 C）记录的新生儿协议持续时间范围为 27:33 至 37:06 分钟。
新生儿协议的声级跨越了现有的风险概念，超过了已知会引起新生儿非听觉反应的声级，但未超过 IEC MRI SPL 安全限值。
5 级技术功效：5 级。
