Functional magnetic resonance imaging was used to identify the neural correlates of Chinese character and word reading. The Chinese stimuli were presented visually, one at a time. Subjects covertly generated a word that was semantically related to each stimulus. Three sorts of Chinese items were use
Recovery of the rodent brain after cardiac arrest: A functional mri study
✍ Scribed by Bernd Schmitz; Mathias Hoehn-Berlage; Christian M. Kerskens; Bernd W. Bottiger; Prof. Dr. Konstantin-Alexander Hossmann
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 722 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Recovery of the cerebral cortex after 10 min of cardiac arrest was studied in rat using noninvasive MRI techniques. The apparent diffusion coefficient (ADC) of brain water was imaged to document reversal of the metabolic impairment. Per‐fusion‐weighted imaging and blood oxygen level dependent (BOLD) imaging were performed to assess functional recovery. To this purpose, rats were anesthetized with α‐chloralose, and somatosensory cortex was activated by electrical stimulation of the contralateral forepaw. In sham‐operated controls, cortical ADC was 862 ±10 μm^2^/s, and stimulation of forepaw led to a focal increase of signal intensity in somatosensory cortex by 71 ± 22% in perfusion‐weighted images and by 6 ± 1 % in BOLD images. One hour after successful resuscitation following 10 min of cardiac arrest, ADC did not differ from control but functional activation was completely suppressed. After 3 hours of reperfusion, functional activity began to reappear but the recovery of the BOLD signal progressed faster than that of the perfusion‐weighted signal. The differences in the recovery of ADC, BOLD, and perfusion imaging are related to differences between metabolic and functional recovery on one hand and between blood flow and oxygen extraction on the other. The combination of these MRI methods thus provides detailed qualitative information about the progression of brain recovery after transient circulatory arrest.
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