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Updated: Jun 17, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Influence of fluid-attenuated inversion-recovery on stroke apparent diffusion coefficient measurements and its
Jian-Ming Ni1, Monique A Mogensen, Zeng-Ai Chen
1Medical Imaging Department, Wuxi Second Hospital Affiliated Nanjing Medical University, 68 Zhong Shan Road, Wuxi, Jiangsu Province 214002, China.
Background And Purpose:
The application of a fluid-attenuated inversion-recovery pulse with a conventional diffusion-weighted MRI sequence (FLAIR DWI) decreases the partial volume effects from cerebrospinal fluid on apparent diffusion coefficient (ADC) measurements. For this reason, FLAIR DWI may be more useful in the evaluation of ischemic stroke, but few studies have looked at the effect of FLAIR on ADC measurements in this setting. This study quantitatively compares FLAIR DWI and conventional DWI in ischemic stroke of varying ages to assess the potential advantages of this technique.
Methods:
We respectively analyzed 139 DWI studies in patients with ischemic stroke with and without FLAIR at varying time points ranging from hyperacute to chronic. ADC values were measured in each lesion, as well as in the contralateral normal side. Comparisons were made between the ADC values obtained from the DWI sequences with and without FLAIR for both the lesion and the normal contralateral side.
Results:
The ADC measurements within the ischemic lesion were very similar on FLAIR DWI and conventional DWI for lesions less than 14 days old (p>0.05), but were significantly decreased on FLAIR DWI for lesions between 15 and 30 days old and in lesions >31 days old (chronic stage) (p<0.01). The contralateral ADC values were all significantly decreased on the FLAIR DWI sequence compared with conventional DWI (p<0.01).
Conclusions:
The application of an inversion pulse does not significantly affect the ADC values for early stage ischemic stroke (less than 14 days from symptom onset), but results in a more accurate relative ADC measurement by reducing the cerebrospinal fluid partial volume effects of the normal contralateral side. In addition, combined with the conventional DWI, FLAIR DWI may be helpful in determining the age of ischemic lesions.
Insights
Fluid-attenuated inversion-recovery diffusion-weighted MRI (FLAIR DWI) offers more accurate apparent diffusion coefficient (ADC) measurements in chronic ischemic stroke by reducing cerebrospinal fluid effects. This technique may aid in determining lesion age.
Area of Science:
- Neuroimaging
- Radiology
- Medical Physics
Background:
- Diffusion-weighted MRI (DWI) is crucial for evaluating ischemic stroke.
- Cerebrospinal fluid (CSF) partial volume effects can impact apparent diffusion coefficient (ADC) measurements.
- Fluid-attenuated inversion-recovery (FLAIR) sequences may mitigate CSF partial volume effects in DWI.
Purpose of the Study:
- To quantitatively compare FLAIR DWI and conventional DWI in ischemic stroke.
- To assess the impact of FLAIR on ADC measurements across different stroke ages.
- To evaluate the potential advantages of FLAIR DWI in stroke assessment.
Main Methods:
- Analysis of 139 DWI studies in ischemic stroke patients (hyperacute to chronic).
- Measurement of ADC values in lesions and contralateral normal tissue.
- Comparison of ADC values between FLAIR DWI and conventional DWI sequences.
Main Results:
- No significant difference in ADC measurements for lesions <14 days old (p>0.05).
- Significantly decreased ADC values on FLAIR DWI for lesions aged 15-30 days and >31 days (p<0.01).
- Significantly decreased contralateral ADC values on FLAIR DWI compared to conventional DWI (p<0.01).
Conclusions:
- FLAIR DWI does not significantly affect ADC in early ischemic stroke (<14 days).
- FLAIR DWI provides more accurate relative ADC measurements by reducing CSF partial volume effects.
- FLAIR DWI may assist in determining the age of ischemic lesions.
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