MR diffusion weighted imaging detecting cerebral infarction:a Meta-analysis

Objective To determine the diagnostic value of diffusion-weighted imaging(DWI)in hyperacute and acute cerebral infarction by using Meta-analysis.Methods Based on validity criteria for diagnostic research published by the Cochrane Methods Group on Screening and Diagnostic,studies in English and Chinese from 1 997 to 2007 were selected from Medline,Cochrane,Springer,Ovid,Elsevier,LWW and CNKI(China National Knowledge Infrastructure).The characteristics of the included articles were appraised and extracted. Statistical analysis was performed with the software Meta-test 0.6 and Comprehensive meta-analysis 2.0.Heterogeneity of the included articles was tested.which was used to select proper effect model to calculate pooled weighted values of sensitivity and specificity and the corresponding 95% CL Summary receiver operating characteristic(SROC)curve was performed and the area under the curve(Az)was calculated.Publication bias was analyzed by Funnel Plot in Comprehensive Meta.analysis 2.0.A sensitivity analysis was performed.Results Twelve articles meeting inclusion criteria were analyzed for the value of DWI in hyperacute cerebral infarction.The pooled seusitivitv.specificity and diagnostic odds ratio was 92%,87%,180.37 respectively,Az=0.9717.Novice is a main factor for total diagnostic effect(Q=4.34,P>0.05).Non-asymmetric funnel plot suggested the publication bias.Fifteen articles meeting inclusion criteria were analyzed for the value of DWI in both hyperacute and acute cerebral infarction(≤24 h).The pooled sensitivity,specificity diagnostic odds ratio was 92%、91%. 623.62 respectively.Az=0.9659.Fixed effects model used in Meta-analysis for database suggested homogeneity(Q=2.70,P>0.05).Nonasymmetrie funnel plot suggested the publication bias.Conclusions As a noninvasive method,diffusion-weighted imaging is valuable in detecting hyperacute and acute cerebral infarction.More support from multi-center prospective researches is desirable. Key words: Cerebral infarction; Diffusion magnetic resonance image;  Meta analysis;  ROCeUrve