Comparison of Silent and Conventional MR Imaging for the Evaluation of Myelination in Children

Abstract

Purpose:Silent magnetic resonance imaging (MRI) scans produce reduced acoustic noise and are considered more gentle for sedated children. The aim of this study was to compare the validity of T1- (T1W) and T2-weighted (T2W) silent sequences for myelination assessment in children with conventional spin-echo sequences.Materials and Methods:A total of 30 children (21 boys, 9 girls; age range: 1–83 months, mean age: 35.5 months, median age: 28.5 months) were examined using both silent and spin-echo sequences. Acoustic noise levels were analyzed and compared. The degree of myelination was qualitatively assessed via consensus, and T1W and T2W signal intensities were quantitatively measured by percent contrast.Results:Acoustic noise levels were significantly lower during silent sequences than during conventional sequences (P < 0.0001 for both T1W and T2W). Inter-method comparison indicated overall good to excellent agreement (T1W and T2W images, κ = 0.76 and 0.80, respectively); however, agreement was poor for cerebellar myelination on T1W images (κ = 0.14). The percent contrast of silent and conventional MRI sequences had a strong correlation (T1W, correlation coefficient [CC] = 0.76; T1W excluding the middle cerebellar peduncle, CC = 0.82; T2W, CC = 0.91).Conclusions:For brain MRI, silent sequences significantly reduced acoustic noise and provided diagnostic image quality for myelination evaluations; however, the two methods differed with respect to cerebellar delineation on T1W sequences.

Low intensity white noise improves performance in auditory working memory task: An fMRI study

“…As a consequence, we may miss some of the relevant BOLD response. There are increasing numbers of research in the field of silent MRI imaging [52, 53], and hopefully, the next generation of MRI scanners will totally be silent. It has been shown that the nature of the task may potentially influence the effects of white noise on cognitive performance [30].…”

Image quality assessment of silent T 2 PROPELLER sequence for brain imaging in infants

“…Therefore, a method to optimize gradient waveforms was developed and the sequence is called either the "Silent" or "Quiet" sequence. 14,16,22 The technique has been applied to T1WI, T2WI and FLAIR, 14,17 but not yet in other sequences such as DWI.…”

“…14 There was one previous study comparing images of the silent T 1 and T 2 weighted image (T1WI, T2WI) PROPELLER technique with that of T1WI spin echo and T2WI fast spin-echo sequences in children in terms of myelination degree. 17 The study compared both the sequences that were acquired by different imaging planes, slice thickness, or matrix, which made hard to match the quality of silent PROPELLER imaging. In addition, the study included patients of a wide age range.…”

Techniques for minimizing sedation in pediatric MRI

“…This loud noise often can wake a sedated child (especially neonates and infants), leading to suspended examinations and the need for additional sedatives. Some methods can reduce noise, including the use of diminished gradient slew rate and slow ramps for k ‐space readout . Insulation of the inner bore of the magnet and inserting ear plugs and covering the ears with noise attenuators can reduce the noise experienced by children .…”

“…Some methods can reduce noise, including the use of diminished gradient slew rate and slow ramps for k-space readout. 29,30 Insulation of the inner bore of the magnet and inserting ear plugs and covering the ears with noise attenuators can reduce the noise experienced by children. 30 However, the effects of those methods are limited.…”