MRI and DTI in evaluation on vascular cognitive impairment of rat models / 中国医学影像技术

ABSTRACT

Objective To explore the imaging indexes of early diagnosis of vascular cognitive impairment (VCI).Methods Totally 30 rats were collected and divided into model group (n=20) and control group (n=10).Modified 4-VO method was used to establish the VCI rat models.Morris water maze test was used to detect learning and memory abilities of rats.T2W and DTI scanning were performed in all rats 2 weeks,1 month,3 months and 5 months after operation,respectively.ROI was used to analyze the change of hippocampal volume and FA value.Voxel-based analysis (VBA) was used to analyze the change of FA value in all brain on DTI images.Then the rats were sacrificed,HE staining and Nissl staining of brain tissue slices were performed to observe the morphological changes.Results Compared with control group,the learning and memory ability of rats in model group decreased significantly.Compared with the control group,the hippocampal volume and FA value in model group decreased significantly at 3 months and 5 months after operation,respectively (all P＜0.05).FA in many brain areas reduced 1,3,5 months after operation in model group (all P＜0.05),and the decrease regions expanded with time going.Pyramidal cells in the hippocampal showed degeneration and nuclear condensation,and cytoplasmic Nissl bodies demonstrated reduction and disappearance gradually.Conclusion Changes of rat hippocampal volume and microscopic white matter may be helpful to early diagnosis of VCI.Decrease of FA value can be used as an indicator for early diagnosis and severity evaluation of VCI.