Objective: To perform a meta-analysis to explore the evolutions of apparent diffusion coefficient during different stages of ischemic stroke.
Methods: The relevant English and Chinese articles published from 2001 to 2010 were retrieved from the databases of Cochrane Library, Pubmed, Elsevier and Chinese Knowledge Resource Integrated Database (CNKI). According to the criteria of diagnostic researches published by the Cochrane Method Group on Screening & Diagnostic Tests, each article was critically appraised. We tested their heterogeneity, selected the corresponding effect model and calculated pooled weighted effect size and corresponding 95% CI.
Results: By the established inclusion criteria, we retrieved 34 studies with 20 English and 14 Chinese articles. The pooled apparent diffusion coefficient (ADC) values of diffusion weighted imaging-magnetic resonance imaging (DWI-MRI) and 95%CI of hyper-acute, acute, sub-acute, chronic stroke were 0.53 (0.45 - 0.60), 0.50 (0.47 - 0.53), 0.66 (0.62 - 0.70), 1.20 (1.01 - 1.38) while those of penumbra and control were 0.70 (0.68 - 0.89) and 0.87 (0.84 - 0.91) respectively. The ADC values of hyper-acute and acute stroke were obviously lower than that of penumbra and it had statistical significance (both P < 0.05). The ADC values of hyper-acute, acute, sub-acute and chronic stroke were obviously different from that of control and it had statistical significance [0.53 (0.45 - 0.60) × 10(-3) s/mm, 0.50 (0.47 - 0.53) × 10(-3)s/mm, 0.66 (0.62 - 0.70) × 10(-3)s/mm, 1.20 (1.01 - 1.38) × 10(-3)s/mm vs 0.87 (0.84 - 0.91) × 10(-3)s/mm, all P < 0.05].
Conclusions: As indicated by our meta-analysis, the ADC values can quantitatively evaluate different stages of stroke and guide the choices of treatment methods.