Objective:To explore the evaluation of dual-parameter three dimension arterial spin labelling(3D-ASL)perfusion imaging on blood-supply situation of patients with chronic middle cerebral artery occlusion(CMCAO)and the relationship between that and cerebral infarction area.Methods:A total of 112 patients with unilateral CMCAO admitted to Handan Central Hospital from April 2019 to December 2021 were selected,and all of them were divided into a compensatory group(50 cases)with anterior cerebral artery(ACA)leptomeningeal anastomoses(LMA)and an uncompensated group(62 cases)according to the results of digital subtraction angiography(DSA)examination.The results of diffusion weighted imaging(DWI),magnetic resonance angiography(MRA)and dual-parameter 3D-ASL detection were respectively analyzed,and the clinical data,3D-ASL parameters and the incidence of cerebral infarction between the two groups were compared.The influence factors of compensation were further analyzed.The receiver operating characteristics(ROC)curve of LMA diagnostic value of CMCAO patients was drawn according to cerebral blood flow values[post label delay(PLD)=1.5 s,2.5 s)].The 3D-ASL parameters of patients with different cerebral infarction areas were compared,and the relationship between 3D-ASL parameters and cerebral infarction area was compared.Results:The apparent diffusion coefficient(ADC)at the side of lesion of CMCAO patients was(0.31±0.10),and cerebral blood flow values at 1.5s and 2.5s were respectively(25.67±4.25)and(54.09±4.49),which were significantly lower than those at the side of healthy,and the differences were statistically significant(t=27.591,34.210,3.913,P<0.05),respectively.The differences of cerebral blood flow values(1.5s and 2.5s)between compensatory group and uncompensated group were significant(t=5.584,4.090,P<0.05),respectively.The results of logistic regression analysis showed that age,stroke,cerebral infarction area and cerebral blood flow values(1.5 s and 2.5 s)were influencing factors on LMA compensation of CMCAO patients(OR=4.187,6.604,0.482,5.681,5.807,P<0.05),respectively.The ROC values showed that the area under curve(AUC)of 3D-ASL were respectively 0.720 and 0.812 in diagnosing LMA when PLD were respectively 1.5s and 2.5s.The proportion of normal and lacunar infarctions in the compensatory group was significantly higher than that in the uncompensated group,while the proportions of middle and small infarction,and large area infarctions of the compensatory group were significantly lower than those of the uncompensated group,and the difference was statistically significant(t=28.062,P<0.05).The difference in cerebral blood flow values(1.5s)among patients with different infarct areas was statistically significant(t=0.202,P<0.05).The cerebral blood flow value(1.5s)of 3D-ASL was negatively correlated with the area of cerebral infarction(r=-0.261,P<0.05).Conclusion:Dual parameter 3D-ASL can non-invasively and visually assess the compensatory status of LMA of patients with unilateral CMCAO.The blood flow perfusion of middle cerebral artery(MCA)at the side of lesion is related to the area of cerebral infarction.When the PLD is 1.5s,the sensitive response can be conducted on this,so as to provide objective and reliable basis for clinical diagnosis and treatment and curative effect.

BACKGROUND:The combination of good biomechanical properties,controlled drug release and multi-functionality of core-shell structured nanofibers is receiving more and more attention,which also makes them promising for a wide range of applications in the field of oral tissue regeneration. OBJECTIVE:To summarize the preparation,drug loading and release mechanisms of core-shell structured nanofibers and their application in the regenerative repair of oral tissues. METHODS:A computer search of the literature collected in CNKI and PubMed from January 2000 to November 2022 was applied,and the search terms in English and Chinese were"electrospinning,core-shell structures,drug delivery systems,jaw bone regeneration,cartilage regeneration,periodontal tissue regeneration". RESULTS AND CONCLUSION:(1)There are various methods for the preparation of core-shell structured nanofibers,but the coaxial and emulsion methods of electrostatic spinning have unique advantages such as simple operation,diverse material selection and good biocompatibility.(2)Core-shell structured nanofibers can be used as bacteriostatic agents,carriers of different types of drugs,and scaffolds for cell adhesion,providing new therapeutic options for oral tissue regeneration.(3)Controlled degradation and drug release rate of core-shell structured nanofibers can better adapt to the healing process of oral tissue defect repair and achieve ideal tissue regeneration.