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 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.

The coantioxidative effects of carboxyethyl-6-hydroxychromans and alpha-Tocopherol.

alpha-Tocopherol (alpha-Toc) is abundant in LDL and thought to prevent the oxidation of LDL together with various water-soluble antioxidants. Recently, it was reported that alpha-Toc and gamma-Toc metabolites, alpha-carboxyethyl-6-hydroxychromans (CEHC) and gamma-CEHC, are water-soluble antioxidants. In this study, we investigated the interaction between alpha-Toc and CEHC against 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and LDL oxidation. We administered 600 mg of alpha-Toc to healthy male volunteers to obtain LDL including high levels of alpha-Toc before antioxidant administration. The alpha-Toc content of their LDL was increased after consumption at 24 h (18.3 microg/mL) above the level before consumption (6.6 microg/mL). The lag time of LDL at 24 h after alpha-Toc consumption (alpha-Toc rich LDL) with alpha-CEHC (98.5+/-8.2 min) or gamma-CEHC (101.3+/-9.0 min) was longer than that of only alpha-Toc-rich LDL (78.1+/-9.0 min). Furthermore, we examined the interaction of LDL with CEHC and alpha-Toc in vitro (5-20 microg/mL). The lag times of 5 and 10 microg/mL alpha-Toc were 65.5+/-18.9 min and 69.5+/-15.5 min, and that of 20 microg/mL alpha-Toc (83.5+/-20.2 min) was longer than the control value (55.7+/-14.1 min). The lag time of 20 microg/mL alpha-Toc with alpha-CEHC (98.7+/-25.7 min) or gamma-CEHC (100.6+/-25.3 min) was longer than that of only alpha-Toc (83.5+/-20.2 min). These results suggest that CEHC has the potential to delay the oxidation of LDL, while enhancing the antioxidative activity of alpha-Toc both in vitro and ex vivo.