ABSTRACT
Objective To explore the relationship between structure and function in the diseases of posterior visual pathways as well as the anatomic mechanism of the abnormal visual responses.Methods Eleven cases of diseases of posterior visual pathways(3 gliomas,4 meningiomas,3 metastasis,1 stroke) involving either cortical or subcortical visual pathways were investigated by combining fMRI and DTI.fMRI was performed by using flashing checkerboard at 8 Hz.For imaging processing,fMRI analysis was performed with SPM99,and DTI and tractography with DTVⅡ.Fractional anisotropy(FA) of optic radiations and activated volume(VOXELs) of primary visual cortices(V1 and V2) were measured and analyzed at the affected side and the contralateral side.Relative FA(rFA) and relative activated volume(rVOXELs) were also calculated.3D tractography of optic radiations was performed successfully in 11 patients.Results In the patients with brain tumors,FA values in the affected side of optic radiations were significantly different with the contralateral side(P