The evolution of acute stroke recorded by multimodal magnetic resonance imaging

Quast, Michael J.; Huang, Ning; Hillman, Gilbert R.; Kent, Thomas A.

doi:10.1016/0730-725x(93)90465-p

Cited by 122 publications

(54 citation statements)

References 23 publications

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“…5,6 Because the MRI contrast medium is an intravascular tracer, the DSC-MRI provides a measure of cerebral blood volume (CBV) as the area under the concentration-time curve of the contrast agent. Studies of animal ischemia model [7][8][9][10][11] and human acute infarction [12][13][14][15] have shown a decrease in CBV in the vascular territory of steno-occlusive lesions. Although CBV is a fundamental factor in hemodynamic studies of ischemic brain disorder, few studies have reported the relationship between CBV and cerebral blood flow (CBF) in acute stroke patients.…”

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confidence: 99%

Cerebral Blood Volume in Acute Brain Infarction

Hatazawa

Shimosegawa

Toyoshima

et al. 1999

Stroke

101

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Background and Purpose-The aim of this study was to correlate the abnormality in cerebral blood volume (CBV) measured by dynamic susceptibility contrast-enhanced MRI with that in cerebral blood flow (CBF) estimated by single-photon emission CT with [ 99m Tc]hexamethylpropylenamine-oxime in patients with acute ischemic stroke. Methods-Nine patients with unilateral occlusion of either the middle cerebral artery or the internal carotid artery (4 men and 5 women; meanϮSD age, 74.4Ϯ11.6 years) were studied within 6 hours after stroke onset. The relative CBV (relCBV) and CBF (relCBF) in the lesions were defined relative to the contralateral mirror regions. Results-In the brain regions with mild (relCBF Ն0.60), moderate (0.40ՅrelCBFϽ0.60), and severe (relCBF Ͻ0.40) hypoperfusion, the mean relCBV values were 1.29Ϯ0.31, 0.94Ϯ0.49, and 0.30Ϯ0.22, respectively. The relCBV was significantly elevated in the brain areas with mild hypoperfusion (PϽ0.001) and significantly reduced in the brain areas with severe hypoperfusion (PϽ0.001). The relCBF was significantly better than the relCBV in predicting the evolution of infarction (PϽ0.02). The probability of evolving infarction for the hypervolemic (relCBV Ͼ1.0) regions was significantly lower than that for hypovolemic (relCBV Ͻ1.0) regions in the relCBF range between 0.40 and 0.50 (PϽ0.02). Conclusions-In acute ischemic stroke within 6 hours of onset the CBV can be either increased, normal, or decreased, depending on the severity of hypoperfusion. The increased CBV has a protective effect on evolving infarction. Although the CBF is a better predictor of tissue outcome, the CBV measurement may help detect potentially salvageable brain tissue in the penumbra with compromised blood flow. (Stroke. 1999;30:800-806.)

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confidence: 99%

Cerebral Blood Volume in Acute Brain Infarction

Hatazawa

Shimosegawa

Toyoshima

et al. 1999

Stroke

101

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“…The lesion area in each slice was multiplied by the slice thickness and summed to yield the total lesion volume in cubic millimeters. This technique using threshold values was used in previous studies in our laboratory (Huang et al, 1996;Quast et al, 1993Quast et al, , 1995Quast et al, , 1997Wei et al, 1997;Wei and Quast, 1998). The region of the no-flow zone was estimated in a similar fashion using the signal-void region in PVI, which represented the area where no detectable intravascular tracer had perfused into the tissue (Kent et al, 1989(Kent et al, , 1990Quast et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Ischemic lesions, estimated from DWI, were calculated based on intensity threshold segmentation using image analysis software developed in the Medical Imaging Laboratory at UTMB (Quast et al, 1993). Regions of restricted water diffusion measured in DWI were considered to represent cytotoxic edema (Knight et al, 1991;Moseley et al, 1990;Verheul et al, 1994), whereas regions of prolonged T 2 relaxation time in T 2 WI represented vasogenic edema (Knight et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

Effects of 2-Deoxy-D-Glucose on Focal Cerebral Ischemia in Hyperglycemic Rats

Wei

Cohen

Quast

2003

J Cereb Blood Flow Metab

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Summary:The authors examined the effects of pretreatment with 2-deoxy-D-glucose (2DG) on the middle cerebral artery occlusion-reperfusion (MCAO/R) model in hyperglycemic rats. Proton magnetic resonance imaging and spectroscopy were used to measure the lesion size, the level of cerebral perfusion deficit, and ratio of lactate to N-acetyl aspartate (NAA) in brain regions. By performing sequential diffusion weighted imaging, gradient echo bolus tracking, steady-state spin echo imaging, and water-suppressed proton magnetic resonance spectroscopy techniques, the time course of the early changes of the lactate/NAA peak ratio and perfusion deficit was examined in hyperglycemic rats undergoing 90-minute MCAO followed by 24-h reperfusion. Compared with the saline-treated hyperglycemic rats, 2DG treatment at 10 minutes before MCAO significantly reduced diffusion weighted imaging hyperintensity by ∼60% and the lactate/NAA peak ratio by ∼70% at 4 h after MCAO/R. Both spin echo-measured cerebral blood volume and dynamic gradient echo-relative cerebral blood flow showed that the restoration of blood supply recovered and remained at ∼80% of baseline during reperfusion in 2DG-treated hyperglycemic rats. These data suggest that inhibition of glucose metabolism by 2DG has a beneficial effect in reducing brain injury and minimizing the production of brain lactate during MCAO/R in hyperglycemic rats. Key Words: Cerebral ischemia-Magnetic resonance imaging-NMR spectroscopy-Hyperglycemia-2-Deoxy-D-glucose-Lactate.The cerebral concentration and supply of glucose influence the outcome of cerebral ischemia. Elevated blood glucose at the onset of brain ischemia is well known to be associated with a worsened neurologic outcome (David and Bell,1994;Huang et al.,1996; Li and Siesjo,1997; Nedergaard and Diemer,1987;Yip et al., 1991; ). The detrimental effect of hyperglycemia on cerebral ischemia is considered to be mediated by the release of excitatory amino acids, additional formation of free radicals and enhanced accumulation of lactic acid, followed by a further decrease in intracellular and extracellular pH (Li and Siesjo,1997;Li et al., 1999Li et al., , 2000Siesjo et al., 1990Siesjo et al., , 1993Wei et al., 1997;Wei and Quast, 1998). By using 31 P MRS, we observed that the preexisting hyperglycemic rat brain intracellular pH values were 6.14 ± 0.18 and 6.08 ± 0.19 during MCAO and reperfusion (Quast MJ, Wei J, Sell S, unpublished data, 1996), which is consistent with previous studies (Haraldseth et al.,1992;Suttle et al., 1992;Widmer et al., 1992) that showed hyperglycemia-related acidosis aggravates ischemic brain damage due to decreased intracellular and extracellular pH. It is assumed that lactate production in ischemic brain is a result of anaerobic metabolism of the higher concentration of available glucose (Li et al., 1994;Siesjo et al., 1993;Tyson et al.,1993). It has been reported that pretreatment with 2DG reduces brain damage and improves behavioral outcome in a normoglycemic rat focal ischemia model (Yu and Mattson, 1999)...

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“…Ischemic areas are identified by either a lesser degree of signal intensity loss, a delay in the arrival of the bolus, or an increase in the transit time of the bolus. In an attempt to quantify CBF, tracer kinetic theory has been applied to signal-intensity changes during first-pass bolus tracking (17,18); however, controversies exist on the validity of these methods, especially during focal cerebral ischemia (2,5). Nevertheless, the high spatial resolution of the MR technique and its ease of use seem to compensate for some partial volume effects.…”

Section: Discussionmentioning

confidence: 99%

Does a relative perfusion measure predict cerebral infarct size?

Engelhorn¹,

Doerfler²,

Heusch³

et al. 2004

Akt Neurol

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BACKGROUND AND PURPOSE: MR perfusion-weighted imaging (PWI) has been extensively used to quantify cerebral perfusion deficits after the onset of focal ischemia. The present study tested whether a relative measure of cerebral blood flow such as is obtained with PWI is sufficient to predict irreversible tissue damage following focal cerebral ischemia and reperfusion in the rat suture model. METHODS:In rats, the middle cerebral artery was occluded ( CONCLUSION: The present study revealed that absolute CBF is superior to relative CBF in predicting irreversible tissue damage following ischemia and reperfusion.

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The evolution of acute stroke recorded by multimodal magnetic resonance imaging

Cited by 122 publications

References 23 publications

Cerebral Blood Volume in Acute Brain Infarction

Cerebral Blood Volume in Acute Brain Infarction

Effects of 2-Deoxy-D-Glucose on Focal Cerebral Ischemia in Hyperglycemic Rats

Does a relative perfusion measure predict cerebral infarct size?

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