Di-san junyi daxue xuebao (May 2022)
Evaluation of ventriculoperitoneal shunt in patients with secondary normal pressure hydrocephalus by diffusion tensor imaging
Abstract
Objective To evaluate the efficacy of ventriculoperitoneal shunt in patients with secondary normal pressure hydrocephalus by using the diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT). Methods 3.0T MRI was performed on 22 patients before and 1 month after their ventriculoperitoneal shunts, DTI and DTT imaging were performed simultaneously. We recorded the values of fractional anisotropy (FA) and mean diffusivity(MD) around the ventricle, the number of white matter fiber tracts around the lateral ventricle, and the orientation and distribution of neural fiber tracts. Results After ventriculoperitoneal shunts were performed, the values of FA and MD were decreased significantly (P < 0.01), the number of white matter fiber tracts around the lateral ventricle were obviously increased (P < 0.01), and the compression rate of fiber tracts was reduced (P < 0.01). Among the poor rehabilitative patients, the values of FA and MD around the ventricle were decreased significantly (P < 0.01). We calculated the differences of FA value (dFA) and MD value (dMD) and the number of fiber tracts before and after operation, the results suggested that the dFA was higher in the patients of better rehabilitation than those of poor rehabilitative outcomes. The dMD were higher and the number of fiber tracts was increased in the better rehabilitative patients(P < 0.01). Conclusion The relevant items of DTI and DTT are significantly improved in the poor effective patients with normal pressure hydrocephalus after ventriculoperitoneal shunt. The changes of FA value around the lateral ventricle can predict the efficacy of the surgery. DTI and DTT techniques provide certain and valuable guidance for the organic improvement after ventriculoperitoneal shunt.
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