Quantitative estimation of intravoxel incoherent motion parameters in acute ischemic stroke: A Systematic review and meta-analysis

Background: Intravoxel incoherent motion (IVIM) is a potential diagnostic technique for acute ischemic stroke as it simultaneously quantifies the molecular diffusion and the minute capillary network microcirculation; however, the lack of comprehensive evidence of its utility in acute ischemic stroke necessitates a review to enable better quantitative estimation and understanding of IVIM parameters and their relation with parameters of conventional diffusion and perfusion techniques. Methods: An extensive search strategy yielded 2340 studies in six databases. After a two-step screening process, data from 10 studies were extracted and included in the meta-analysis. Heterogeneity, publication bias, and forest plot analysis were performed for each IVIM parameter: D, D*, f, and fD*. Results: The mean values for D ranged from 0.28 to 0.58 × 10^{− 3} mm²/s and from 0.56 to 0.93 × 10^{− 3} mm²/s in the lesion and contralateral normal region, respectively, with the standardised mean difference of 3.24 SD units and positive correlation with ADC. f-values were between 2.5 and 4.9% ipsilaterally and 4.3 to 7.9% contralaterally, with minimal heterogeneity and a statistically significant standardised mean difference of 2.65 SD units. D* showed a non-significant effect. fD* showed a significant standardised mean difference of 1.48 SD units. Conclusion: Quantitative differentiation between the core and normal regions was significantly seen in D, f, and fD* parametric maps. Although D* varied across studies, technical upgrading could improve its utility. Since IVIM parameters correlate well with the existing diffusion and perfusion parameters, its utility offers a robust, multifaceted approach to understanding acute ischemic stroke. Clinical trial number: Not applicable.