Article Figures & Data
Figures
- Fig 1.
An 86-year-old man with acute onset left-sided weakness after elective cardiac surgery, NIHSS:8. Axial DWI (4500/90, b = 1000 s/mm2) (A), FLAIR (9000/88/2500) (B), and EPI-FLAIR (10,000/106/2500) (C) images obtained 4.5 hours after the onset of symptoms. Watershed infarctions are noted along the right cerebral hemisphere deep white matter zones. Note the comparable image quality between FLAIR and EPI-FLAIR, both demonstrating increased signal intensity in the region of DWI abnormality, indicative of completed infarctions. Acquisition time for FLAIR was 3 minutes; for EPI-FLAIR, it was 52 seconds.
- Fig 2.
A 60-year-old man with sudden-onset left-sided weakness after an aneurysm coil was placed for a proximal supraclinoid ICA aneurysm. Axial DWI (4500/90, b = 1000 s/mm2) (A), FLAIR (9000/88/2500) (B), and EPI-FLAIR (10,000/106/2500) (C) obtained approximately 60 minutes after onset of symptoms. Acute infarction along the right MCA territory is noted. The signal intensity ratio of the lesion to the contralateral hemisphere was elevated and measured 1.19 for FLAIR and 1.15 for EPI-FLAIR. Qualitatively, however, very subtle increased hyperintensity corresponding to the region of DWI abnormality is evident on FLAIR but is not clearly seen on EPI-FLAIR. Note the susceptibility artifacts related to the dislodged coil in the MCA bifurcation, which is more pronounced on EPI-FLAIR (arrow) and likely contributed to field inhomogeneity and may have explained the qualitative discrepancy with FLAIR. Note the hyperintense vessel sign (arrowheads) on both FLAIR and EPI-FLAIR caused by sluggish flow or clot in the sylvian MCA branches.
- Fig 3.
Bland-Altman plots and scatterplot show significant correlation (r = 0.899; z value = 8.677; P < .0001) for the SIR values between FLAIR and EPI-FLAIR in patients with acute infarction (DWI-positive lesions [n = 38]).
Tables
N DWI FLAIR (Signal) EPI-FLAIR (Signal) Conclusion 12 − − − No ischemic infarction 10 + − − Concordant FLAIR–EPI-FLAIR, early stage of ischemic infarction 26 + + + Concordant FLAIR–EPI-FLAIR, completed infarction 2 + + − EPI-FLAIR discordant with FLAIR FLAIR SIR EPI-FLAIR SIR T Test (P Value) DWI negative (−) FLAIR, (−) EPI-FLAIR (n = 12) 1.02 ± 0.005 1.02 ± 0.006 .2 DWI positive <4.5 hours of time from onset to MR imaging (n = 12) 1.14 ± 0.08 1.10 ± 0.06 .22 >4.5 hours of time from onset to MR imaging (n = 22) 1.36 ± 0.16 1.33 ± 0.17 .83 (+) FLAIR, (−) EPI-FLAIR (n = 2) 1.15 ± 0.03 1.13 ± 0.05 /Aa Note:—Data are mean ± standard deviation.
↵a In 2 discrepant cases, the SIR values were comparable. The sample was too small for evaluation with the t test.
In 4 patients with unknown time of presentation, the SIR values were concordant between FLAIR and EPI-FLAIR (SIR > 1.3, n = 3; SIR < 1.3, n = 1).
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