European Radiology

, Volume 29, Issue 12, pp 7019–7026 | Cite as

Synthetic T2 mapping is correlated with time from stroke onset: a future tool in wake-up stroke management?

  • Thomas Duchaussoy
  • Jean-François Budzik
  • Laurene Norberciak
  • Lucie Colas
  • Marta Pasquini
  • Sebastien VerclytteEmail author



FLAIR-DWI mismatch is an effective method to select eligible wake-up stroke (WUS) patients for intravenous thrombolysis, but shows limitations in the case of subtle FLAIR hyperintensities. T2 mapping is a quantitative method, directly generated from synthetic MRI, which provides T2 relaxation times. We aimed to assess the correlation between T2 values and onset time in acute stroke patients.


We prospectively included stroke patients in the 4.5-h window undergoing brain MRI including MAGnetic resonance Image Compilation (MAGiC) from March to October 2017. T2 relaxation times and FLAIR signal intensities were measured in ischemic and contralateral nonischemic regions to calculate FLAIR signal intensity ratio (rSI), difference, and ratio of T2 values. Correlation analysis with time from the onset was achieved using Pearson or Spearman correlation coefficient (ρ) test.


Forty-two patients were included. The strongest correlation with the time from onset was the difference in T2 relaxation times (ρ = 0.71; CI95% = [0.48; 0.85]), followed by the ratio (ρ = 0.65; CI95% = [0.37; 0.82]) and the absolute T2 relaxation time (ρ = 0.4; CI95% = [0.06; 0.66]), whereas the FLAIR rSI showed the weakest correlation (ρ = 0.18; CI95% = [− 0.16–0.51]).


The difference and ratio in T2 relaxation times were correlated with the onset time in stroke patients in the 4.5-h window. T2 mapping generated from synthetic MRI may become a relevant tool to select WUS patients with subtle FLAIR hyperintensities. Given that no definitive statement can be made about its usefulness in the 4.5-h windows, further study including patients with an onset time > 4.5 h is required.

Key Points

• The difference and ratio in T2 relaxation times are each individually correlated with the time from stroke onset in the 4.5-h window.

• FLAIR rSI showed a poor correlation with the time from stroke onset.

• T2 mapping, directly generated from synthetic MRI, may be a suitable quantitative marker to select safely WUS patients with subtle FLAIR hyperintensities for intravenous thrombolysis.


Stroke Acute stroke Magnetic resonance imaging 



MAGnetic resonance Imaging Compilation


National Institutes of Health Stroke Scale


Signal intensity ratio


Wake-up stroke



The authors state that this work has not received any funding.

Compliance with ethical standards


The scientific guarantor of this publication is Pr Sebastien Verclytte.

Conflict of interest

The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.

Statistics and biometry

One of the authors has significant statistical expertise.

Informed consent

Written informed consent was waived by the Institutional Review Board.

Ethical approval

Institutional Review Board approval was obtained.


• Prospective

• Observational

• Performed at one institution


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Copyright information

© European Society of Radiology 2019

Authors and Affiliations

  1. 1.Imaging Department, Lille Catholic HospitalsLille Catholic UniversityLilleFrance
  2. 2.Biostatistics Department - Delegations for Clinical Research and Innovation, Lille Catholic HospitalsLille Catholic UniversityLilleFrance
  3. 3.Department of Neurology, Lille Catholic HospitalsLille Catholic UniversityLilleFrance

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