Brain Tissue Water Uptake after Middle Cerebral Artery Occlusion Assessed with CT

Dzialowski, Imanuel; Weber, Johannes; Doerfler, Arnd; Forsting, Michael; Kummer, Rüdiger von

doi:10.1111/j.1552-6569.2004.tb00214.x

Cited by 107 publications

(71 citation statements)

References 25 publications

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“…26 In the permanent MCAO of rat, total water content has been shown to remain unchanged for the first 2 hours of ischemia. 27,28 In fact, delayed increase in tissue water content is the key reason behind the low sensitivity of CT to acute stroke. 27 Thus, there is evidence to show that total tissue water content does not increase significantly within the first hour of ischemia and, therefore, cannot explain T 1 (or T 2 ) MR signal increase.…”

Section: Jokivarsi Et Al Stroke Onset Time Estimation Using T 1 and Tmentioning

confidence: 99%

“…27,28 In fact, delayed increase in tissue water content is the key reason behind the low sensitivity of CT to acute stroke. 27 Thus, there is evidence to show that total tissue water content does not increase significantly within the first hour of ischemia and, therefore, cannot explain T 1 (or T 2 ) MR signal increase. 29 It should be stressed that MRI signal, weighted for either diffusion or relaxation, is influenced by several other physicochemical factors than total water concentration.…”

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confidence: 99%

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Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats

Jokivarsi

Hiltunen

Gröhn

et al. 2010

Stroke

100

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Background and Purpose-Time of ischemia onset is the most critical factor for patient selection for available drug treatment strategies. The purpose of this study was to evaluate the abilities of the absolute longitudinal rotating frame (T 1 ) and transverse (T 2 ) MR relaxation times to estimate the onset time of ischemia in rats. Methods-Permanent middle cerebral artery occlusion in rats was used to induce focal cerebral ischemia and animals were imaged with multiparametric MRI at several time points up to 7 hours postischemia. Ischemic parenchyma was defined as tissue with apparent diffusion coefficient of water Ͻ70% from that in the contralateral nonischemic brain. Results-The difference in the absolute T 1 and T 2 between ischemic and contralateral nonischemic striatum increased linearly within the first 6 hours of middle cerebral artery occlusion. The slopes for T 1 and T 2 fits for both tissue types were similar; however, the time offsets were significantly longer for both MR parameters in the cortex than in the striatum. Conclusions-T 1 and T 2 MRI provide estimates for the onset time of cerebral ischemia requiring regional calibration curves from ischemic brain. Assuming that patients with suspected ischemic stroke are scanned by MRI within this timeframe, these MRI techniques may constitute unbiased tools for stroke onset time evaluation potentially aiding the decision-making for drug treatment strategies. (Stroke. 2010;41:2335-2340.)Key Words: acute stroke Ⅲ animal models Ⅲ brain imaging Ⅲ brain ischemia Ⅲ MRI C ollapse of adenosine 5Ј-triphosphate due to acute ischemia is associated with subtle changes in both ionic and water homeostasis in the brain. Altered homeostasis in the brain is probed by MR techniques to follow ionic and water signals during the evolution of ischemia. 1,2 Diffusion and T 2 MRI form the cornerstones for imaging diagnosis of stroke as supplemented by hemodynamic sensitive perfusion MRI techniques. 3 Combined use of these MRI techniques with T 2 * MRI allows accurate diagnosis of acute stroke as well as separation of ischemic and hemorrhagic stroke.A major challenge for imaging of acute stroke remains to provide an accurate estimate for the duration of ischemia. The duration of ischemia is one of the key factors determining the choice of patient management at hospital admission, including application of currently available drug treatment strategies. Thrombolysis must be initiated within 3 to 4.5 hours of onset of symptoms to render beneficial effect on patient outcome, yet with acceptable adverse effects. 4,5 Similarly, other treatment methods such as hypothermia provide a beneficial outcome when applied within a time window of 3 to 6 hours after the onset. 6 Several neuroprotective drugs have shown an effect in preclinical settings only when administered within a narrow time window from stroke onset. 7 It is well established by electrophysiological and tissue ion analysis techniques that brain sodium increases in a linear fashion after ischemia. 8 Based on this fact, it has be...

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Section: Jokivarsi Et Al Stroke Onset Time Estimation Using T 1 and Tmentioning

confidence: 99%

mentioning

confidence: 99%

Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats

Jokivarsi

Hiltunen

Gröhn

et al. 2010

Stroke

100

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“…14,15 Physiologically, the NCCT hypodensities of acute infarction represent water uptake in the ischemic brain tissue as shown in a recent rat model study of MCA occlusions, in which a 1% increase in net brain water content corresponded to a reduction in x-ray attenuation of 1.8 Hounsfield units (HU). 16 CT hypoattenuation has a significant correspondence to critically hypoperfused tissue as seen by PET. 17 These early hypodensities have been shown to have a positive predictive value for stroke as seen on follow-up CT scans of 87%.…”

Section: Noncontrast Ctmentioning

confidence: 94%

Neuroimaging of ischemia and infarction

Camargo

Koroshetz

2005

Neurotherapeutics

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Summary:Since the introduction of thrombolytic therapy as the foundation of acute stroke treatment, neuroimaging has rapidly advanced to empower therapeutic decision making. Diffusionweighted imaging is the most sensitive and accurate method for stroke detection, and, allied with perfusion-weighted imaging, provides information on the functional status of the ischemic brain. It can also help to identify a response to thrombolytic and neuroprotective therapies. Additionally, multimodal magnetic resonance imaging, including magnetic resonance angiography, offers information on stroke mechanism and pathophysiology that can guide long-term medical management. Multimodal computed tomography is a comprehensive, cost-effective, and safe stroke imaging modality that can be easily implemented in the emergency ward and that offers fast and reliable information with respect to the arterial and functional status of the ischemic brain. Accessibility, contraindications, cost, speed, and individual patient-determined features influence which is the best imaging modality to guide acute stroke management.

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“…It is well known that CT attenuation and brain water content are inversely correlated [61]. The age related difference in image attenuation is highly correlated with the progression of myelination [62,63].…”

Section: Cerebral Edema Scorementioning

confidence: 99%

Quantitative analysis of computed tomography images and early detection of cerebral edema for pediatric traumatic brain injury patients: retrospective study

Kim

Yoon

et al. 2014

BMC Medicine

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Brain Tissue Water Uptake after Middle Cerebral Artery Occlusion Assessed with CT

Abstract: After MCA occlusion, immediate brain tissue net water uptake is associated with a decrease in x-ray attenuation. CT can monitor ischemic edema in an acute stroke.

Cited by 107 publications

References 25 publications

Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats

Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats

Neuroimaging of ischemia and infarction

Quantitative analysis of computed tomography images and early detection of cerebral edema for pediatric traumatic brain injury patients: retrospective study

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Brain Tissue Water Uptake after Middle Cerebral Artery Occlusion Assessed with CT

Abstract: After MCA occlusion, immediate brain tissue net water uptake is associated with a decrease in x-ray attenuation. CT can monitor ischemic edema in an acute stroke.

Cited by 107 publications

References 25 publications

Estimation of the Onset Time of Cerebral Ischemia Using T 1ρ and T 2 MRI in Rats

Estimation of the Onset Time of Cerebral Ischemia Using T 1ρ and T 2 MRI in Rats

Neuroimaging of ischemia and infarction

Quantitative analysis of computed tomography images and early detection of cerebral edema for pediatric traumatic brain injury patients: retrospective study

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Product

Resources

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Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats

Estimation of the Onset Time of Cerebral Ischemia Using T _1ρ and T ₂ MRI in Rats