ABSTRACT
Objective To analyze the correlation between white matter injury and cognitive dysfunction using diffusion tensor imaging (DTI).Methods Seventeen subjects with TBI hospitalized from October 2012 to September 2013 had Glasgow coma scale (GCS) score of ≥ 13 (mild injury group, 10 cases) and ≤ 12 (moderate-severe injury group, 7 cases).Another 17 healthy subjects were used as controls.All were submitted to DTI examination.Fractional anisotropy (FA) and apparent diffusion coefficient(ADC) values in genu corpus callosum, splenium corpus callosum, posterior internal capsule, anterior internal capsule, and cerebral peduncle were calculated using the Neuro 3D software.Correlations between FA and ADC with the mini-mental state examination (MMSE) score were evaluated.Results Moderate-severe injury group demonstrated significantly reduced FA values in genu corpus callosum and splenium corpus callosum, and significantly increased ADC values of genu corpus callosum, splenium corpus callosum, posterior internal capsule and cerebral peduncle when compared to control group (P ＜0.05 or 0.01).FA and ADC values in the regions of interest did not differ significantly between mild injury group and control group (P ＞ 0.05).In the genu corpus callosum and splenium corpus callosum, FA values were positively correlated with MMSE score (r =0.636, 0.601), while ADC values were negatively correlated with MMSE score (r =0.552, 0.660).Conclusions DTI reveals the cerebral white matter lesion that is undetectable using CT and conventional MRI.DTI is a helpful tool to evaluate the degree of cognitive function in patients with TBI, which provides the basic reference for the clinical treatment and prognosis.
ABSTRACT
Objective To establish animal models of diffuse axonal injury (DAI) and discuss the early functional MRI findings.Methods Twenty-five adult white rabbits were divided into control group (n =5),mild DAI group and severe DAI group (n =6) according to random number.Mild DAI group was subdivided into mild DAI 3 h (n =6),1 day (n =4) and 1 week (n =4) groups.Routine MRI and diffusion tensor imaging (DTI) were performed.Parameters measured were fractional anisotropy (FA),apparent diffusion coefficient (ADC),axial diffusivity (AD) and radical diffusivity (RD).Results Significantly increased FA (P＜0.01) and decreased ADC (P＜0.05) and RD (P＜0.01) were detected in severe DAI group compared to control group,but there was no significant variation in AD between the two groups (P ＞ 0.05).Each parameter remained almost unchanged in mild DAI 3 h group and mild DAI 1 week group,but FA was increased (P ＜ 0.01) and RD decreased (P ＜ 0.05) in mild DAI 1 day group,with no changes of ADC and AD.Conclusion DTI is a sensitive way to detect the occurrence and development of DAI and can provide referential images for early DAI diagnosis.