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Objective To compare metabolite ratios in the basal ganglia regions between preterm and term neonates and analyze the correlation between metabolite ratio and postmenstrual age(PMA)using 2D magnetic resonance spectroscopy(MRS)at 3.0T,so as to explore the value of MRS in evaluating neonatal brain development.Methods Normal neonates who underwent 3.0T MRS exam ination were recruited.Axial 2D MRS was performed with the point-resolved spectroscopy sequence(PRESS)(echo time/repetition time,144 ms/1 000 ms) through the basal ganglia covering three regions of interest(ROI)(i.e.bilateral lenticular nucleus,thalamus and white matter beside the anterior horn of lateral ventricle).The peak areas ratios of Cho/Cr,NAA/Cho and NAA/Cr were calculated.Metabolite ratios were compared between preterm and term neonates,and between three ROIs. Correlation between metabolite ratio and PMA was further analyzed.Results Totally 54 neonates were included(preterm/term,27/27).In all the three ROIs,preterm neonates presented significantly higher Cho/Cr(P＜0.05) and significantly lower NAA/Cho ratios(P＜0.001)than those of term neonates;higher NAA/Cr ratio was only observed in the lenticular nucleus of preterm neonates(P＜0.001).Significant differences in metabolite ratios were detected among the three ROIs in preterm group(P＜0.05).For term group,metabolite ratios differed between lenticular nucleus and white matter beside the anterior horn of the lateral ventricle(P＜0.01),while no difference between lenticular nucleus and thalamus was found(P＞0.05).Significant correlation between metabolite ratio and PMA was found in all the three ROIs except NAA/Cr ratio in the white matter beside the anterior horn of the lateral ventricle.To be specific,we found linear negative correlation of Cho/Cr ratio(r= -0.325,-0.633,-0.438) and positive correlation of NAA/Cho ratio(r = 0.604,0.773,0.483)in all the three ROIs,but negative correlations of NAA/Cr ratio(r=0.487,0.367)in lenticular nucleus and thalamus with PMA.Conclusion Our findings suggest the tempo-spatial pattern of neonatal brain metabolite development in terms of anatomic location and PMA.Besides,the multi-voxel MRS presents potentials in establishing the normal topologic and age-matched reference in neonates and thus making brain maturation assessment and detection of early abnormal metabolism.
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Objective To explore the significance of signal classification by multimodal magnetic resonance imaging(MRI)(including conventional MRI,diffusion imaging,and susceptibility-weighted imaging)on neonatal punctate white matter lesions(PWML).Methods Between March 2011 and February 2013,neonates with PWML who underwent 3.0T MRI examination were recruited.The routine protocols included T1 weighted imaging (T1WI),T2 weighted imaging(T2WI),diffusion tensor imaging(DTI),and 3D-enhanced susceptibility-weighted angiography(ESWAN).Apparent diffusion coefficient(ADC)map,magnitude image,and phase image were obtained from DTI and ESWAN,respectively.The signal of PWML was one-to-one observed on T1WI,T2WI, ADC map and magnitude image.The combined signals were classified and the number of cases of each type was counted.Results Totally 84 neonates with PWML were included(preterm/term,47/37).Seven signal types were found and classified into three groups: ① Type Ⅰ was the most,59 cases,accounting for 70.24%,with the performance of high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and high-signal intensity on magnitude image. ② Type Ⅱ,7 cases,accounting for 8.33%,high-signal intensity on T1WI,low-signal intensity on T2WI,low-signal intensity on ADC map,and low-signal intensity on magnitude image.③ Type Ⅲ - Ⅶ,26 cases,accounting for 30.95%,high-signal intensity on T1WI,low/iso-signal intensity on T2WI,low/iso-signal intensity on ADC map,high/iso-signal intensity on magnitude image.There was no significant difference in the incidence of different signal types between preterm and full-term PWML neonates. Conclusion Magnetic resonance signal may reflect the characteristics of PWML lesions.Signal classification of PWML by multimodal magnetic resonance imaging is helpful in determining injury type and has certain significance in guiding clinical treatment.
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This study was aimed to establish the HPLC fingerprints of the genus Chimonanthus leaves and compare the constituents distribution among five Chimonanthus species . The analysis was conducted on a C15 column (4.6 mm x 250 mm, 5 microm) with the mobile phase containing acetonitrile-water in gradient program: acetonitrile (B), 0-20 min, 6%-20%; 20-30 min, 20%-25%; 30-40 min, 25%-45%; 40-50 min, 45%-80%; 50-80 min, 80%-85%; 80-90 min, 85%-100%; 90-110 min, 100%. Flow rate was 0.8 mL x min(-1) and detection wavelength was 228 nm. Column temperature was set at 30 degrees C. The HPLC fingerprints of the five Chimonanthus species have been established. Ch. praecox, Ch. nitens, Ch. salicifolius, Ch. Zhejiangensis and Ch. grammatus have significant difference in constituents distribution and contents. Five standard substances as common compounds were confirmed in chromatography fingerprints. The method can be used as quality evaluation and classicfication of the genus Chimonanthus.