Retrospective study demonstrates improved geometric accuracy in acute ischemic stroke, indicating that structural MRI effectively corrects diffusion-weighted imaging artifacts.
Key Points
To determine whether structural imaging-based artifact correction reduces susceptibility-induced geometric distortions and non-physiologic hyperintensities in clinical acute ischemic stroke diffusion weighted imaging (DWI).
Retrospective analysis of 214 patients with acute ischemic stroke across two centers imaged with 1.5 T or 3 T MRI protocols.
Applied Synb0-DisCo and TOPUP algorithms to correct DWI distortions using b0 and T1-weighted structural images.
Evaluated geometric alignment using mutual information against FLAIR and T1-weighted images, and measured diagnostic accuracy against apparent diffusion coefficient (ADC)-defined infarcts.
DWI demonstrated significantly increased mutual information post-correction against FLAIR images [0.31 (IQR, 0.25–0.38) vs 0.30 (0.24–0.35)] and T1-weighted images [0.32 (IQR, 0.29–0.36) vs 0.29 (0.24–0.33); Bonferroni-adjusted p < 0.05].
DWI hyperintensities showed strong pre-to-post correction correlation (R² = 0.996) with a negative bias of 2.47 mL (95% CI, 1.95–3.00 mL).
Correction significantly improved the specificity [0.998 (IQR, 0.994–1.000) vs 0.997 (0.992–0.999)] and positive predictive value [0.53 (IQR, 0.31–0.77) vs 0.39 (0.16–0.63)] of DWI hyperintensities for ADC-defined infarcts.