The study of radiologically isolated syndrome using MR diffusion tensor imaging / 中华放射学杂志

ABSTRACT

Objective To study whether abnormalities can be detected by MR diffusion tensor imaging (DTI) technology in radiologically isolated syndrome (RIS) patients with normal-appearing white matter (NAWM).Methods Twenty-seven patients who met diagnostic criteria for RIS were collected.Sixteen age-and sex-matched healthy controls with normal neurologic examination findings and no history of neurologic or psychopathic disorders were included.All subjects were examined by both conventional scan and DTI scan on GE Signa 3.0 T MRI.All the images were transmitted to the Advantage Workstation 4.2P and postprocessed using functool software.Anisotropic maps and average diffusion coefficient (ADC) maps were reconstructed.Two ROIs were selected in the genu and splenium of the corpus callosum separately at the trigone of lateral ventricle level.Other 2 ROIs were selected in the anterior and posterior body of the corpus callosum separately at the level of the lateral ventricle body,and 1 ROI was selected in the white matter of bilateral frontal and occipital lobe separately,then the FA and MD values were measured.The diffusion indices (FA and MD)were analysed by SPSS 13.0.Independent-sample t test was performed to examine the group differences in each subregion.Intraclass correlation coefficient analysis was performed to assess the diffusion indices of two measurements in each subregion.Results The ICC of 2 measurements was 0.934-0.989 (P ＜ 0.01),which showed favorable consistency.The FA values were decreased obviously in the genu,anterior and posterior body of the corpus callosum of the RIS patients compared with controls (0.705 ±0.040 vs 0.738 ±0.045,0.632 ±0.043 vs 0.675 ±0.042,0.628 ±0.043 vs 0.666 ± 0.045,t =-3.526,-4.487,-3.890,P ＜0.01),but the FA values of the two groups did not show any significant difference in the splenium,the white matter of the frontal and occipital lobe respectively (t =-1.387,-0.683,-1.243,P ＞0.05).In comparison with controls,the RIS patients had increased MD values in the genu,anterior and posterior body of the corpus callosum.(0.891 ±0.038 vs 0.874 ±0.035,0.839 ± 0.047 vs 0.794 ± 0.031,0.833 ± 0.039 vs 0.792 ± 0.057,t =2.101,5.836,5.146,P ＜ 0.05),but the MD values of the two groups did not show any significant difference in the splenium,the white matter of the frontal and occipital lobe respectively (t =1.671,1.702,1.624,P ＞ 0.05).Conclusion The NAWM abnormalities in the patients with radiologically isolated syndrome could be detected by DTI.