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
The influence of acute and intermittent hypoxia on respiratory mechanics in the range of tidal volume of adult rabbits was studied. All is based on the assumption that the tissue structure of lung constitutes a conservative mechanical system and hence that pressure(P)-volume(V)hysteresis is primarily a result of surface tension(r)-surface area(s)hysteresis. It was found that the lung compliance of rabbits to acute hypoxia was decreased and respiratory work increased. Compared to control group (3.5?1.1mm),the working limbs of P-V loops of acute hypoxic rabbits increased by 49% (5.2?0.6mm). Such changes could be corrected in part by appropriate intermittent hypoxia, the length of working limbs of 5-day adaptation rabbits was 4.2?1.1(P