Detection of Carotid Atherosclerotic Intraplaque Neovascularization Using Superb Microvascular Imaging: A Meta‐Analysis

OBJECTIVES: Although superb microvascular imaging (SMI) (Toshiba/Canon, Tokyo, Japan) has enabled routine characterization of intraplaque neovascularization (IPN) features in patients with carotid stenosis, no reports have been published on the multicenter and large sample size research in this aspect. The efficacy of SMI in detecting carotid IPN has not been concluded. This study aimed to assess the efficacy of SMI comparing with contrast-enhanced carotid ultrasonography (CEUS) in the detection of carotid IPN or pathologic evaluations of IPN correlated with a history of stroke or transient ischemic attack (TIA). METHODS: Web of Science, Cochrane Library, PubMed, Embase, and Scopus were searched up to August 2020 to identify peer-reviewed human studies on the diagnostic accuracy of SMI in detecting IPN. For the selected study, the correlation coefficient R and Kappa index between SMI and CEUS in detecting IPN were calculated. The correlation coefficient R between SMI in identifying IPN and pathologic evaluations of IPN and the odds ratio of IPN detected by SMI and history of stroke or TIA were also extracted. The subgroup analysis was performed to indicate the source of heterogeneity. RESULTS: Our search identified 11 reports enrolling a total of 605 carotid stenosis patients. Carotid IPN detected by SMI was significantly correlated with which detected by CEUS (R, 0.89; 95% CI, 0.80-0.94; P = .00, and Kappa index, 0.73; 95% CI, 0.67-0.80; P = .00). Notably, a significant correlation was observed in SMI in detecting IPN and pathologic evaluations of IPN (R, 0.52; 95% CI, 0.40-0.62; P = .00). The odds ratio of IPN detected by SMI and history of stroke or TIA was pooled summary with statistical significance (OR, 3.33; 95% CI, 1.78-6.23; P = .00). In subgroup analysis, lower heterogeneity was associated with the degree of carotid stenosis, patients from which country, and types of equipment. CONCLUSIONS: SMI and CEUS display an excellent agreement in detecting carotid IPN. IPN detected by SMI shows high consistency with pathologic evaluations of IPN. Individuals with carotid IPN are more likely to develop stroke or TIA than those without carotid IPN.