Objective　To explore the clinical value of 3D artistic spin labeling technology in evaluating early perfusion changes of leukaraiosis.Methods　Ninety patients and 30 healthy volunteers with different degrees of LA who were examined by magnetic resonance imaging were collected from January 2018 to April 2020.According to the Fazekas scale,they were divided into LA0,LA1,LA2 and LA3 group,30 cases were included in each group.CBF values of cortical watershed and subcortical watershed were measured according to cerebral blood flow pseudocolor image,and cerebral perfusion differences in anterior,posterior,radial crown and semicircular center of cortical watershed in different LA grades were evaluated,and the characteristics of early hemodynamic changes of LA were analyzed.Results　The CBF values of LA2,LA3 were significantly lower than that of LA0.There was no significant difference between LA1 and LA0 (P>0.05),however,the CBF in subcortical watershed was slightly lower than LA0 (P<0.05).Conclusion　3D ASL perfusion imaging technology can be used to quantify the CBF in the watershed area,and can be used to monitor the state of cerebral perfusion in LA patients.The CBF response in the subcortical watershed area is more sensitive,which can be used to evaluate the early cerebral hemodynamic changes in LA.

OBJECTIVE：To es tablish the HPLC fingerprint of Arnebia euchroma ，analyze them with chemical pattern recognition technology ， and determine the contents of 3 components. METHODS ： HPLC method was adopted. Using acetylshikonin as reference ，HPLC fingerprint of 34 batches of A. euchroma from different sources were drawn. Similarity Evaluation System for TCM Chromatographic Fingerprint （2012A edition ）was used to evaluate the similarity of the samples ，and common peaks were determined. SPSS 19.0 and SIMCA 14.1 statistical software was used for cluster analysis ，principle component analysis and orthogonal partial least squares-discriminate analysis. According to the standard of the variable importance in the project greater than 1，the differential markers affecting the quality difference of A. euchroma were screened. Meanwhile ，the contents of 3 components were determined by the same HPLC method. RESULTS ：There were 12 common peaks in HPLC fingerprints for 34 batches of A. euchroma . The similarity of other samples were more than 0.86，except that t he three （No.2016A3005-5） batches of medicinal herbs on the market were less than 0.72；3 common peaks were identified ， such as shikonin ，acetylshikonin， β ，β ′-dimethylacrylic acanine. These 34 batches of samples could be classified into two categories . S 1， qq.com S4-S6，S13，S15-S20，S22，S26-S34 were clustered into one category，and others clustered into the other category. By principal component analysis ，the contribution rates of three principle components were 52.834％ ，18.600％ and 8.387％ . Accumulative contribution rate was 79.821％ . Six constituents，such as shikonin，acetylshikonin and β，β'-dimethylacrylic acanine were screened as differential markers，representing the major differences of A. euchroma . The linear range of above three components were 0.72-90，2.05-410，2.50-500 µg/mL（r all more than 0.999）， respectively. The limits of quantification were 0.132，0.135，0.118 µg/mL，respectively. The limits of detection were 0.040，0.041， 0.036 µg/mL，respectively. RSDs of precision ，stability（24 h），reproducibility and durability tests were all lower than 3％. Recoveries were 95.959％-100.201％（RSD＝1.669％，n＝6），97.818％-102.698％（RSD＝1.788％，n＝6），95.831％-99.344％ （RSD＝1.600％，n＝6）. The contents of above three components were 0.002％-0.134％，0.025％-1.388％，0.022％-0.881％. CONCLUSIONS：Established HPLC fingerprint and content determination method are simple and stable ，can be used for quality evaluation and quantitative analysis of A. euchroma . Shikonin ，acetylshikonin and β，β'-dimethylacrylic acanine are different in the content and are differential markers of A. euchroma from different source.