RESUMEN
Objective To evaluate the possibility of diffusion tensor imaging(DTI)in detecting and quantifying the Wallerian degeneration of optic radiation in occipital lobe chronic infarction.Methods 20 patients with unilateral occipital chronic infarction were undergone DTI.Quantitative fractional anisotropy(FA)and mean diffusivity(MD)were obtained from the ipsilateral optic radiation of the occipital lobe infarction and compared with that of contralateral region using the independent samples t-test.Results On the three dimensional color-coding tensor fractional anisotropic map,the regions of occipital lobe chronic infarction were markedly low signal intensity,the FA value and MD value were 0.274?0.062 and(1.226?0.372)?10-3mm2/s,while in the contralateral region of optic radiation,FA and MD values were 0.495?0.035 and(0.775?0.070)?10-3mm2/s respectively,there was significant difference in FA and MD values in comparing both side(P〈0.01).Conclusion DTI can detect and quantify the Wallerian degeneration in optic radiation after occipital lobe chronic infarction.