METHODS: Both ‘non-ischaemic reference’-dependent and -independent estimators were generated. Apparent diffusion coefficient (ADC), T2 and T1ρ, were sequentially quantified for up to 6 hours of stroke in rats (n = 8) at 4.7T. The ischaemic lesion was identified as a contiguous collection of voxels with low ADC. T2 and T1ρ in the ischaemic lesion and in the contralateral non-ischaemic brain tissue were determined. Differences in mean MRI relaxation times between ischaemic and non-ischaemic volumes were used to create reference-dependent estimator. For the reference-independent procedure, only the parameters associated with log-logistic fits to the T2 and T1ρ distributions within the ADC-delineated lesions were used for the onset time estimation.
RESULT: The reference-independent estimators from T2 and T1ρ data provided stroke onset time with precisions of ±32 and ±27 minutes, respectively. The reference-dependent estimators yielded respective precisions of ±47 and ±54 minutes.
CONCLUSIONS: A ‘non-ischaemic anatomical reference’-independent estimator for stroke onset time from relaxometric MRI data is shown to yield greater timing precision than previously obtained through reference-dependent procedures.
- Brain and Behaviour
- Cognitive Science
- Ischaemic stroke
- magnetic resonance imaging
- MRI relaxometry
- stroke onset time
FingerprintDive into the research topics of 'Stroke onset time determination using MRI relaxation times without non-ischaemic reference in a rat stroke model'. Together they form a unique fingerprint.
Jade Thai (Manager), Chiara Bucciarelli-Ducci (Other) & Iain Gilchrist (Other)Bristol Medical School (THS)