ABSTRACT
Objective To investigate the value of diffusion tensor imaging(DTI)in the evaluation of diffuse microstructural changes in early stage of spinal cord injury (SCI)in rats.Methods Improved Allen's method was used to make SCI in rats model.The rats were divided in the group of four as control,mild,moderate and severe injury groups respectively.We used DTI parameters [fraction anisotropy (FA)and apparent diffusion coefficient(ADC)]values to observe the spinal cord at different stages (6,24 and 72 hours) after spinal injury in the rats.Results The FA value of the spinal cord began to decrease at 6 hours and reached the lowest at 24 hours after SCI (P<0.05).There were significant differences in FA values between mild,moderate,and severe injury groups (P<0.05). However,ADC value was seen decreased only in the severe injury group,which was lowest at 24 hours after SCI(P<0.05).Conclusion Compared with ADC value,FA value can better reflect the severity of spinal cord injury in rats with acute SCI.FA values are correlated with the degrees of injury of spinal cord.
ABSTRACT
Objective To discuss the prognostic evaluation of magnetic resonance diffusion tensor imaging (DTI) in term neonates with mild and severe asphyxia.Methods Eleven neonates with mild asphyxia,14 neonates with severe asphyxia and 10 control neonates were studied.All the neonates were examined by conventional magnetic resonance imaging(MRI) and DTI.Fraction anisotropy (FA) values,apparent diffusion coefficient (ADC) values,voxel numbers and fiber numbers were calculated in seven regions of interest(ROI) and compared among the 3 groups.The correlation between FA values and neonatal behavioral neurological assessment (NBNA) scores were analyzed.Results (1) FA values in the left and the right thalamus were 0.54 ± 0.08 and 0.56 ± 0.15 in control group,0.45 ±0.03 and 0.44 ± 0.10 in mild group,and 0.21 ± 0.11 and 0.25 ± 0.13,respectively in severe group.FA values in posterior limbs of internal capsule were 0.49 ± 0.09 and 0.48 ± 0.08 in control group,0.37 ± 0.08 and 0.38 ± 0.03 in mild group,and 0.20 ± 0.04,0.19 ± 0.13 in severe group;FA values in thalamus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =9.12,9.11,8.18,8.55,all P ＜ 0.05).Voxel numbers in the left and the right superior longitudinal fasciculus were 1 094 ± 112 and 1 123 ± 113 in control group,986 ± 111 and 1 009 ± 144 in mild group,450 ± 116 and 671 ± 126 in severe group.Voxel numbers in anterior limbs of internal capsule were 947 ± 104 and 1 237 ± 184 in control group,854 ± 118 and 799 ± 114 in mild group,324 ± 110 and 311 ± 126 in severe group.Voxel numbers in posterior limbs of internal capsule were 2 047 ± 129 and 2 137 ± 238 in control group,1 843 ± 233 and 1 753 ± 247 in mild group,867 ± 118 and 999 ± 167 in severe group.Voxel numbers in superior longitudinal fasciculus,anterior and posterior limbs of internal capsule had statistical differences among the 3 groups (F =10.11,9.45,7.33,8.45,12.65,11.23,all P ＜ 0.05);Fiber numbers in the left and the right cingulate gyrus were 245 ±72 and 405 ±94 in control group,225 ±52 and 365 ± 114 in mild group,145 ±62 and 185 ±84 in severe group.Fiber numbers in inferior front-occipital fasciculus were 56 ± 19 and 212 ± 33 in control group,49 ±22 and 197 ± 33 in mild group,33 ± 12 and 156 ± 39 in severe group.Fiber numbers in posterior limbs of internal capsule were 284 ± 112 and 988 ± 233 in control group,234 ± 67 and 678 ± 234 in mild group,114 ± 67 and 188 ± 84 in severe group.Fiber numbers in cingulate gyrus,inferior front-occipital fasciculus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =3.11,3.45,9.88,9.12,7.45,8.88,all P ＜ 0.05).(2) The correlation between FA value and NBNA scores was analyzed:the correlation coefficient in posterior limbs of internal capsule was 0.666 which was higher than those of the other areas.The area under the ROC curve of FA values in anterior limbs of internal capsule was 0.816 (P =0.005),used NBNA scores ≥ 35 as a good outcome.FA values (≥ 0.375) in the posterior limbs of the internal capsules predicted a good outcome and the corresponding sensitivity and specificity was 73.1％ and 77.8％,respectively.Conclusion In some ROIs,FA values,voxel numbers,and fiber numbers can quantitatively reflect the degree of white matter injury in neonates with asphyxia.Furthermore,the FA values in the posterior limbs of the internal capsules are closely correlated with NBNA scores,so it has more important clinical significance,and can accurately and objectively assess the prognosis in neonates with asphyxia.
ABSTRACT
Objective To assess the correlation between fractional anisotropy(FA) value and α-SMA of renal tissue in patients with chronic kidney disease (CKD).Methods 33 CKD patients underwent MRI standard scanning and diffusion tensor imaging(DTI).FA values were measured on both medulla and cortex of bilateral kidneys on the FA map.24 patients were performed renal biopsy to detect the expression of α-SMA.The integrated optical density of positive-staining region was calculated for each view.The relationship between the FA values and the integrated optical densities of α-SMA was analyzed by using Bivariate correlation analysis.Results There was a significant negative correlation between the cortical FA values and the integrated optical densities of α-SMA (P=0.001).There was a significant negative correlation between the medullary FA values and the integrated optical densities of α-SMA (P=0.035).Conclusion FA value of DTI was correlated with α-SMA of renal tissue in patients with CKD.
ABSTRACT
Objective To discuss the prognostic evaluation of magnetic resonance diffusion tensor imaging (DTI) in term neonates with mild and severe asphyxia.Methods Eleven neonates with mild asphyxia,14 neonates with severe asphyxia and 10 control neonates were studied.All the neonates were examined by conventional magnetic resonance imaging(MRI) and DTI.Fraction anisotropy (FA) values,apparent diffusion coefficient (ADC) values,voxel numbers and fiber numbers were calculated in seven regions of interest(ROI) and compared among the 3 groups.The correlation between FA values and neonatal behavioral neurological assessment (NBNA) scores were analyzed.Results (1) FA values in the left and the right thalamus were 0.54 ± 0.08 and 0.56 ± 0.15 in control group,0.45 ±0.03 and 0.44 ± 0.10 in mild group,and 0.21 ± 0.11 and 0.25 ± 0.13,respectively in severe group.FA values in posterior limbs of internal capsule were 0.49 ± 0.09 and 0.48 ± 0.08 in control group,0.37 ± 0.08 and 0.38 ± 0.03 in mild group,and 0.20 ± 0.04,0.19 ± 0.13 in severe group;FA values in thalamus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =9.12,9.11,8.18,8.55,all P ＜ 0.05).Voxel numbers in the left and the right superior longitudinal fasciculus were 1 094 ± 112 and 1 123 ± 113 in control group,986 ± 111 and 1 009 ± 144 in mild group,450 ± 116 and 671 ± 126 in severe group.Voxel numbers in anterior limbs of internal capsule were 947 ± 104 and 1 237 ± 184 in control group,854 ± 118 and 799 ± 114 in mild group,324 ± 110 and 311 ± 126 in severe group.Voxel numbers in posterior limbs of internal capsule were 2 047 ± 129 and 2 137 ± 238 in control group,1 843 ± 233 and 1 753 ± 247 in mild group,867 ± 118 and 999 ± 167 in severe group.Voxel numbers in superior longitudinal fasciculus,anterior and posterior limbs of internal capsule had statistical differences among the 3 groups (F =10.11,9.45,7.33,8.45,12.65,11.23,all P ＜ 0.05);Fiber numbers in the left and the right cingulate gyrus were 245 ±72 and 405 ±94 in control group,225 ±52 and 365 ± 114 in mild group,145 ±62 and 185 ±84 in severe group.Fiber numbers in inferior front-occipital fasciculus were 56 ± 19 and 212 ± 33 in control group,49 ±22 and 197 ± 33 in mild group,33 ± 12 and 156 ± 39 in severe group.Fiber numbers in posterior limbs of internal capsule were 284 ± 112 and 988 ± 233 in control group,234 ± 67 and 678 ± 234 in mild group,114 ± 67 and 188 ± 84 in severe group.Fiber numbers in cingulate gyrus,inferior front-occipital fasciculus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =3.11,3.45,9.88,9.12,7.45,8.88,all P ＜ 0.05).(2) The correlation between FA value and NBNA scores was analyzed:the correlation coefficient in posterior limbs of internal capsule was 0.666 which was higher than those of the other areas.The area under the ROC curve of FA values in anterior limbs of internal capsule was 0.816 (P =0.005),used NBNA scores ≥ 35 as a good outcome.FA values (≥ 0.375) in the posterior limbs of the internal capsules predicted a good outcome and the corresponding sensitivity and specificity was 73.1％ and 77.8％,respectively.Conclusion In some ROIs,FA values,voxel numbers,and fiber numbers can quantitatively reflect the degree of white matter injury in neonates with asphyxia.Furthermore,the FA values in the posterior limbs of the internal capsules are closely correlated with NBNA scores,so it has more important clinical significance,and can accurately and objectively assess the prognosis in neonates with asphyxia.
ABSTRACT
Objective To discuss the value of magnetic resonance (MR) diffusion tensor imaging (DTI) technology in the diagnosis of the apparent diffusion coefficient (ADC) and the fraction anisotropy (FA) of neonates with hypoxic-ischemic encephalopathy (HIE) in the subacute stage.Methods Ten cases of normal full-term neonates and 34 term neonates diagnosed with HIE in the subacute stage were investigated with conventional MR and DTI.Of the 34 cases, 15 cases were mild HIE, 12 cases were moderate HIE,7 cases were severe HIE.ADC/FA values in different parts of the brain were analyzed.And the receiver operating characteristic (ROC) curve was used,the sensitivity and specificity of the FA in specific parts were also analyzed.Results (1) On convention MRI : according to the MRl scoring system,score of mild group was(2.6 ±-1.7) points, moderate group was (3.0 ± 1.5) points, severe group was (5.8 ± 1.3) points.There was significant difference between mild group and severe group, moderate and severe group (P ＜ 0.05).(2) The ADC and FA values in each group on DTI : ADC values in all of the regions of interest (ROIs) had no statistic difference between the HIE group and the controls(all P ＞ 0.05).FA values in posterior limb of internal capsule (PLIC) ,splenium had statistic difference between the HIE group and the controls.FA values in mild group were (0.317-0.018,0.339 ±0.025) ,moderate group (0.295 ±0.025,0.324 ±0.026) and severe group (0.252 ±0.039,0.253-0.036) and control group (0.455 ± 0.047,0.372 ± 0.032).(3) ROC analysis of the neonates diagnosed with HIE:the area under the ROC curve of FA values in PLIC, Splenium had statistic difference between mild group and moderate group (P ＜ 0.05).The area under the ROC curve in each group was 0.744 (P =0.032) ,0.658 (P =0.164).ROC curve was used to evaluate the diagnostic accuracy of FA values in PLIC between HIE group and control group,when FA value was lower than 0.337,0.803 was the largest area under the ROC curve, and there was significant difference between them(P ＜ 0.01).Conclusions FA values can reflect the brain white matter WM injury of HIE neonates quantitatively,and its diagnostic veracity is better than ADC value and conventional MR during the subacute phase of HIE.The diagnostic veracity of FA values in PLIC is higher than other parts.When the FA value is lower than 0.337, there is good sensitivity and specificity in diagnosis of HIE, so DTI technology can provide accurate and objective basis for clinical treatment with good sensitivity and specificity about the diagnosis of HIE in early stage.
ABSTRACT
Objective To study the baseline level of fraction anisotropy (FA) and the normal value of apparent diffusion coefficient (ADC) in deep white matter of preterm and its application.Methods From Oct.2010 to Dec.2013,in Department of Neonatology,Jiangsu Province Hospital,magnetic resonance imaging (MRI) (T1,T2) and diffusion tensor imaging (DTI) were done on 13 preterm infants of less than 37 weeks of corrected gestational age (CA),42 preterm infants of term-matched age,and 15 term infants.ADC and FA were measured in genu and splenium of corpus callosum (CC),anterior limb and posterior limb of internal capsule (IC).Results 1.The ADC values in genu,splenium,anterior limb of right IC,posterior limb of right IC,anterior limb of left IC,posterior limb of left IC in CA ＜ 37 weeks infants were higher than those in term-matched infants and in term infants.The ADC values in the 6 regions in term-matched infants and in term infants were significantly different with those in CA ＜ 37 weeks infant(F =5.559,5.775,21.948,19.462,30.586,15.452,all P ＜ 0.01).The differences of ADC values between CA ＜ 37 weeks infants and term-matched infants,between CA ＜37 weeks infants and term infants were significant(all P ＜0.05),except that in CC between CA ＜ 37 weeks infants and term-matched infants.2 The FA values in genu,splenium,anterior limb of right IC,posterior limb of right IC,anterior limb of left IC,posterior limb of left IC in CA ＜ 37 weeks infants were lower than those in term-matched infants and in term infants.The FA values in the 6 regions in term-matched infants and in term infants were significantly different from those in CA ＜ 37 weeks infants (F =9.835,7.500,4.811,11.430,8.674,12.666,all P ＜ 0.01).The differences of FA values between CA ＜ 37 weeks infants and term-matched infants (P ＜ 0.05),between CA ＜ 37 weeks infants and term infants were significant (all P ＜ 0.05).Conclusions The baseline values of FA and ADC in different deep white matters were obtained.As corrected gestational age of preterm babies' increased,FA values in brain white matter increased,while ADC values decreased.The myelination in most white matter of preterm infants at matched term can catch up with that of term infants.The diagnostic value of ADC and FA needs to be studied further.