Carsten Gyldensted

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The authors review the theoretical basis of determination of cerebral blood flow (CBF) using dynamic measurements of nondiffusible contrast agents, and demonstrate how parametric and nonparametric deconvolution techniques can be modified for the special requirements of CBF determination using dynamic MRI. Using Monte Carlo modeling, the use of simple,(More)
This report evaluates several methods to map relative cerebral blood flow (rCBF) by applying both parametric and nonparametric techniques to deconvolve high resolution dynamic MRI measurements of paramagnetic bolus passages with noninvasively determined arterial inputs. We found a nonparametric (singular value decomposition (SVD)) deconvolution technique(More)
The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo- and hypercapnic conditions. After dose normalization and introduction of(More)
The brains of 100 normal adults were examined with 160×160 matrix computed tomography (CT). The left lateral ventricle was found to be larger than the right in both sexes, and both lateral ventricles were larger in the male. There was a statistically significant increase of all cerebral parameters with age, and the cella media index showed a correspondingly(More)
BACKGROUND AND PURPOSE The penumbra of ischemic stroke consists of hypoperfused, but not irreversibly damaged, tissue surrounding the ischemic core. The purpose of this study was to determine viability thresholds in the ischemic penumbra, defined as the perfusion/diffusion mismatch in hyperacute stroke, by the use of diffusion- and perfusion-weighted MRI(More)
OBJECTIVE Conventional cephalometry is an inexpensive and well-established method for evaluating patients with dentofacial deformities. However, patients with major deformities, and in particular asymmetric cases are difficult to evaluate by conventional cephalometry. Both two- and three-dimensional computed tomography (CT) have been proposed to alleviate(More)
OBJECT The authors tested the hypothesis that oxygen metabolism is the key factor linking the long-term viability of ischemic brain tissue to the magnitude of residual blood flow during the first 6 hours following a stroke. METHODS Eleven anesthetized pigs underwent a series of positron emission tomography studies to measure cerebral blood flow (CBF) and(More)
BACKGROUND Central pain following spinal cord injury (SCI) is common and thought to be related to lesion of the spinothalamic pathways. OBJECTIVE To examine additional mechanisms of SCI pain. METHODS Twenty-three SCI patients with traumatic lesions above T10 (14 with central neuropathic pain and 9 without pain) underwent MRI examination. The authors(More)
OBJECT In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral(More)
A new method of in vivo quantitation of peritumoural brain oedema using NMR relaxation time imaging (T1-maps) and Gd-DTPA-enhanced Blood-Tumour-Barrier (BTB) analysis is presented. The method is based on image pixel histogram analysis and a fast imaging method combined with arterial [Gd-DTPA]-measurement. The method was applied in 26 brain tumour patients,(More)