In Vivo Mapping of Local Cerebral Blood Flow by Xenon-Enhanced Computed Tomography

Gur, David; Good, Walter F.; Wolfson, Sidney K.; Yonas, Howard; Shabason, L.

doi:10.1126/science.7058347

Cited by 140 publications

(39 citation statements)

References 16 publications

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“…The quantity Tlapp is the apparent spin-lattice relaxation time, which is a function of the true Ti and perfusion, f (10): 1 f [2] Tlapp Ti A The apparent Ti may be measured by a progressive saturation or inversion recovery experiment. The effective degree of arterial inversion, a', includes the effects of the duty cycle of the labeling pulse and of the transit time, A, for blood to pass from the site of inversion into the capillary beds (17) and is defined by a'= e-e/T(b T-a, \TR/ [3] where Tlb is the spin-lattice relaxation time of arterial blood, Ti0V is the duration ofthe inversion pulse, TR is the repetition time of the pulse sequence, and a is the degree of inversion defined by the labeling pulse at the site ofinversion. Eq.…”

Section: Methodsmentioning

confidence: 99%

“…Existing methods for perfusion imaging involve either injection or inhalation of an exogenous tracer compound. Such compounds include H2150 in positron emission tomography (1,2), xenon in computed tomography (3), and gadolinium chelates (4,5), deuterium (6,7), and fluorocarbons (8,9) in nuclear magnetic resonance imaging (MRI) and spectroscopy studies. Although these techniques have been used successfully to obtain valuable information about cerebral metabolism, they suffer from a number of limitations.…”

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confidence: 99%

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Quantitative magnetic resonance imaging of human brain perfusion at 1.5 T using steady-state inversion of arterial water.

Roberts

Detre

Bolinger

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

167

106

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We report our experience using a noninvasive magnetic resonance technique for quantitative imaging of human brain perfusion at 1.5 T. This technique uses magneticafy inverted arterial water as a freely diffusible blood flow tracer. A perfusion image is calculated from magnetic resonance images acquired with and without arterial blood inversion and from an image of the apparent spin-lattice relaxation time. Single-slice perfusion maps were obtained from nine volunteers with approximately 1 x 2 x 5-mm resolution in an acquisition time of 15 min. Analysis yielded average perfusion rates of 93 + 16 ml 100 g-l-min'1 for gray matter, 38 ± 10 ml 100 g'i.min-1 for white matter, and 52 ± 8 ml 100 g'l min-I for whole brain. Significant changes in perfusion were observed during hyperventilation and breath holding. This technique may be used for quantitative measurement of perfusion in human brain without the risks and expense of methods which use exogenous tracers.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Quantitative magnetic resonance imaging of human brain perfusion at 1.5 T using steady-state inversion of arterial water.

Roberts

Detre

Bolinger

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

167

106

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show abstract

“…Traditionally, perfusion measurements have been made with exogenously administered tracers (1), detected by a variety of techniques. These tracers include xenon, detected by radioactivity or computerized tomography (CT) scans (2), and [150]water and fluoro["C]methane, detected by positronemission tomography (PET) (3,4). Recently, there have been a number of applications of NMR techniques to measure tissue perfusion.…”

mentioning

confidence: 99%

Magnetic resonance imaging of perfusion using spin inversion of arterial water.

Williams

Detre

Leigh

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

1,415

1,253

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A technique has been developed for proton magnetic resonance imaging (MRI) of perfusion, using water as a freely diffusable tracer, and its application to the measurement of cerebral blood flow (CBF) in the rat is demonstrated. The method involves labeling the inflowing water proton spins in the arterial blood by inverting them continuously at the neck region and observing the effects of inversion on the intensity of brain MRI. Solution to the Bloch equations, modified to include the effects of flow, allows regional perfusion rates to be measured from an image with spin inversion, a control image, and a T, image. Continuous spin inversion labeling the arterial blood water was accomplished, using principles of adiabatic fast passage by applying continuous-wave radiofrequency power in the presence of a magnetic field gradient in the direction of arterial flow. In the detection slice used to measure perfusion, whole brain CBF averaged 1.39 ± 0.19 ml'g'1 min-' (mean ± SEM, n = 5). The technique's sensitivity to changes in CBF was measured by using graded hypercarbia, a condition that is known to increase brain perfusion. CBF vs.PCO2 data yield a best-fit straight line described by CBF (ml-g'-minin) = [19F]trifluoromethane (7-9), and chelated gadolinium contrast agents (10), have led to measurements of tissue perfusion.Here we describe an alternative technique for proton magnetic resonance imaging (MRI) of perfusion rates in the brain by using endogenous water as a diffusable tracer. The method involves labeling the water proton nuclear spins in the arterial blood by continuously inverting them in the neck region before they enter the brain. Continuous inversion is accomplished adiabatically, taking advantage of the linear bulk motion of the blood (11). Proton MRI is used to monitor the effects of perfusion delivering the spin-labeled water to the brain. Solutions to the Bloch equations, which describe the time dependence of magnetization, modified to include the effects of flow, allow regional perfusion rates to be calculated from a set of three images. These are an image with spin inversion, a control image, and a T1 image. We apply this technique to the measurement ofrat brain cerebral blood flow (CBF). To assess the technique's sensitivity to changes in perfusion, we have determined CBF under graded hypercarbia, a condition that is known to increase CBF (12). Finally, by generating perfusion images of a freeze-injured rat brain, we demonstrate that the technique can detect abnormalities in regional CBF. MATERIALS AND METHODSAnimal Preparation. Male Sprague-Dawley rats (200-300 g; Taconic Farms) were anesthetized with 5% halothane, orally intubated, and ventilated on 1% halothane and a 1:1 N20/02 mixture. A femoral arterial line was used for monitoring blood pressure and to sample blood for blood gas determinations. The core temperature of the rats was maintained at 37 ± 1PC by using a circulating water pad. Arterial pCO2 was altered by adding various amounts of CO2 to the ventilator gas mixture up to a...

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“…61 Two unenhanced CT images are obtained, then gas is inhaled and six xenon-enhanced images are acquired. The unenhanced images are averaged and subtracted from the enhanced images to obtain a large number of voxels representing the brain xenon concentration in each voxel.…”

Section: Pet and Ctmentioning

confidence: 99%

A review of current imaging methods used in stroke research

Wey

Desai

Duong

2013

Neurological Research

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Stroke is a serious healthcare problem with high mortality and long-term disability. However, to date, our ability to prevent and cure stroke remains limited. One important goal in stroke research is to identify the extent and location of lesion for treatment. In addition, accurately differentiating salvageable tissue from infarct and evaluating therapeutic efficacies are indispensible. These objectives could potentially be met with the assistance of modern neuroimaging techniques. This paper reviews current imaging methods commonly used in ischemic stroke research. These methods include positron emission tomography, computed tomography, T1 MRI, T2 MRI, diffusion and perfusion MRI, diffusion tensor imaging, blood–brain barrier permeability MRI, pH-weighted MRI, and functional MRI.

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In Vivo Mapping of Local Cerebral Blood Flow by Xenon-Enhanced Computed Tomography

Cited by 140 publications

References 16 publications

Quantitative magnetic resonance imaging of human brain perfusion at 1.5 T using steady-state inversion of arterial water.

Quantitative magnetic resonance imaging of human brain perfusion at 1.5 T using steady-state inversion of arterial water.

Magnetic resonance imaging of perfusion using spin inversion of arterial water.

A review of current imaging methods used in stroke research

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