DWI intensity values predict FLAIR lesions in acute ischemic stroke.
PLoS One
; 9(3): e92295, 2014.
Article
en En
| MEDLINE
| ID: mdl-24658092
ABSTRACT
BACKGROUND AND PURPOSE:
In acute stroke, the DWI-FLAIR mismatch allows for the allocation of patients to the thrombolysis window (<4.5 hours). FLAIR-lesions, however, may be challenging to assess. In comparison, DWI may be a useful bio-marker owing to high lesion contrast. We investigated the performance of a relative DWI signal intensity (rSI) threshold to predict the presence of FLAIR-lesions in acute stroke and analyzed its association with time-from-stroke-onset.METHODS:
In a retrospective, dual-center MR-imaging study we included patients with acute stroke and time-from-stroke-onset ≤12 hours (group A nâ=â49, 1.5T; group B nâ=â48, 3T). DW- and FLAIR-images were coregistered. The largest lesion extent in DWI defined the slice for further analysis. FLAIR-lesions were identified by 3 raters, delineated as regions-of-interest (ROIs) and copied on the DW-images. Circular ROIs were placed within the DWI-lesion and labeled according to the FLAIR-pattern (FLAIR+ or FLAIR-). ROI-values were normalized to the unaffected hemisphere. Adjusted and nonadjusted receiver-operating-characteristics (ROC) curve analysis on patient level was performed to analyze the ability of a DWI- and ADC-rSI threshold to predict the presence of FLAIR-lesions. Spearman correlation and adjusted linear regression analysis was performed to assess the relationship between DWI-intensity and time-from-stroke-onset.RESULTS:
DWI-rSI performed well in predicting lesions in FLAIR-imaging (mean area under the curve (AUC) group A 0.84; group B 0.85). An optimal mean DWI-rSI threshold was identified (A 162%; B 161%). ADC-maps performed worse (mean AUC A 0.58; B 0.77). Adjusted regression models confirmed the superior performance of DWI-rSI. Correlation coefficents and linear regression showed a good association with time-from-stroke-onset for DWI-rSI, but not for ADC-rSI.CONCLUSION:
An easily assessable DWI-rSI threshold identifies the presence of lesions in FLAIR-imaging with good accuracy and is associated with time-from-stroke-onset in acute stroke. This finding underlines the potential of a DWI-rSI threshold as a marker of lesion age.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Imagen por Resonancia Magnética
/
Accidente Cerebrovascular
/
Imagen de Difusión por Resonancia Magnética
Tipo de estudio:
Observational_studies
/
Prognostic_studies
Límite:
Aged
/
Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Alemania