A Comparison of T2 Relaxation-Based MRI Stroke Timing Methods in Hyperacute Ischemic Stroke Patients: A Pilot Study

McGarry, Bryony L; Damion, Robin A; Chew, Isabel; Knight, Michael J; Harston, George WJ; Carone, Davide; Jezzard, Peter; Sitaram, Amith; Muir, Keith W; Clatworthy, Philip; Kauppinen, Risto A

Abstract

Background: T2 relaxation-based magnetic resonance imaging (MRI) signals may provide onset time for acute ischemic strokes with an unknown onset. The ability of visual and quantitative MRI-based methods in a cohort of hyperacute ischemic stroke patients was studied.

Methods: A total of 35 patients underwent 3T (3 Tesla) MRI (<9-hour symptom onset). Diffusion-weighted (DWI), apparent diffusion coefficient (ADC), T1-weighted (T1w), T2-weighted (T2w), and T2 relaxation time (T2) images were acquired. T2-weighted fluid attenuation inversion recovery (FLAIR) images were acquired for 17 of these patients. Image intensity ratios of the average intensities in ischemic and non-ischemic reference regions were calculated for ADC, DWI, T2w, T2 relaxation, and FLAIR images, and optimal image intensity ratio cut-offs were determined. DWI and FLAIR images were assessed visually for DWI/FLAIR mismatch.

Results: The T2 relaxation time image intensity ratio was the only parameter with significant correlation with stroke duration (r = 0.49, P = .003), an area under the receiver operating characteristic curve (AUC = 0.77, P < .0001), and an optimal cut-off (T2 ratio = 1.072) that accurately identified patients within the 4.5-hour thrombolysis treatment window with sensitivity of 0.74 and specificity of 0.74. In the patients with the additional FLAIR, areas under the precision-recall-gain curve (AUPRG) and F1 scores showed that the T2 relaxation time ratio (AUPRG = 0.60, F1 = 0.73) performed considerably better than the FLAIR ratio (AUPRG = 0.39, F1 = 0.57) and the visual DWI/FLAIR mismatch (F1 = 0.25).

Conclusions: Quantitative T2 relaxation time is the preferred MRI parameter in the assessment of patients with unknown onset for treatment stratification.

Citation

McGarry, B. L., Damion, R. A., Chew, I., Knight, M. J., Harston, G. W., Carone, D., …Kauppinen, R. A. (2020). A Comparison of T2 Relaxation-Based MRI Stroke Timing Methods in Hyperacute Ischemic Stroke Patients: A Pilot Study. Journal of Central Nervous System Disease, 12, https://doi.org/10.1177/1179573520943314

• Journal Article Type: Article
• Acceptance Date: Jun 29, 2020
• Online Publication Date: Sep 12, 2020
• Publication Date: 2020
• Deposit Date: Nov 28, 2022
• Publicly Available Date: Nov 28, 2022
• Journal: Journal of Central Nervous System Disease
• Electronic ISSN: 1179-5735
• Publisher: Libertas Academica
• Peer Reviewed: Peer Reviewed
• Volume: 12
• DOI: https://doi.org/10.1177/1179573520943314
• Public URL: https://nottingham-repository.worktribe.com/output/4986899
• Publisher URL: https://journals.sagepub.com/doi/10.1177/1179573520943314