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

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 T(1)- (T(1)W) and T(2)-weighted (T(2)W) 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 T(1)W and T(2)W 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 T(1)W and T(2)W). Inter-method comparison indicated overall good to excellent agreement (T(1)W and T(2)W images, κ = 0.76 and 0.80, respectively); however, agreement was poor for cerebellar myelination on T(1)W images (κ = 0.14). The percent contrast of silent and conventional MRI sequences had a strong correlation (T(1)W, correlation coefficient [CC] = 0.76; T(1)W excluding the middle cerebellar peduncle, CC = 0.82; T(2)W, 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 T(1)W sequences.