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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


Bryony L McGarry

Isabel Chew

Michael J Knight

George WJ Harston

Davide Carone

Peter Jezzard

Amith Sitaram

Keith W Muir

Philip Clatworthy

Risto A Kauppinen


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.

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
Public URL
Publisher URL


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