Applying Shear Wave and Magnetic Resonance Elastography to Grade Brain Tumors: Systematic Review and Meta-Analysis

Reports find that magnetic resonance elastography (MRE) and shear wave elastography (SWE) can classify intracranial tumors according to stiffness. However, systematic syntheses of these articles are lacking. In this report, a systematic review and meta-analysis was performed to evaluate whether SWE and MRE can predict meningioma and glioma grades.

PubMed and Scopus were searched between February 10, 2022. and March 2, 2022. using manual search criteria. Eight out of 106 non-duplicate records were included, encompassing 84 patients with low-grade tumors (age 42 ± 13 years, 71% female) and 92 patients with high-grade tumors (age 50 ± 13 years, 42% female). Standardized mean difference in stiffness between high-grade and low-grade tumors were measured using a forest plot. The I², χ², and t tests were performed, and bubble plots were constructed to measure heterogeneity. An adapted QUADAS-2 scale evaluated study quality. Additionally, a funnel plot was constructed, and an Egger's intercept test determined study bias.

Low-grade tumors were stiffer than high-grade tumors (Cohen's D = -1.25; 95% CI -1.88, -0.62). Moderate heterogeneity was observed (I² = 67%; P = 0.006) but controlling for publication year (I² = 0.2%) and age (I² = 0.0%-17%) reduced heterogeneity. Included studies revealed unclear or high bias for the reference standard and flow and timing (>50%).

Elastography techniques have potential to grade tumors intraoperatively and postoperatively. More studies are needed to evaluate the clinical utility of these technologies.