Clemens Fitzek

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PURPOSE To measure mean cerebral blood flow (CBF) in ischemic and nonischemic territories and in low-attenuation regions in patients with acute stroke by using deconvolution-derived hemodynamic imaging. MATERIALS AND METHODS Twelve patients with acute middle cerebral artery stroke and 12 control patients were examined by using single-section computed(More)
Perfusion-and diffusion-weighted magnetic resonance imaging scans are thought to allow the characterization of tissue at risk of infarction. The authors tested the hypothesis that the apparent diffusion coefficient (ADC) decrease should be associated with the severity of the perfusion deficit in ischemic tissue of acute stroke patients. Perfusion-and(More)
PURPOSE To employ a high resolution blood oxygenation level dependent (BOLD) method called susceptibility weighted imaging (SWI) together with the breathing of carbogen to investigate the response of cerebral tumors to this breathing gas and to assess tumor anatomy at high resolution. METHODS Five patients with cerebral tumors (four glioblastoma(More)
BACKGROUND AND PURPOSE Compared with MR imaging, dynamic CT perfusion imaging covers only a fraction of the whole brain. An important assumption is that CT perfusion abnormalities correlate with total ischemic volume. The purpose of our study was to measure the degree of correlation between abnormalities seen on CT perfusion scans and the volumes of(More)
Diffusion tensor imaging (DTI) studies of schizophrenia have revealed white matter abnormalities in several areas of the brain. The functional impact on either psychopathology or cognition remains, however, poorly understood. Here we analysed both functional MRI (during a working memory task) and DTI data sets in 18 patients with schizophrenia and 18(More)
It is occasionally necessary to repeat diffusion weighted imaging (DWI) after giving intravenous contrast medium (CM). However, the effects of CM on DWI and apparent diffusion coefficients (ADC) have not been fully examined. The aim of this prospective study was to investigate whether there are any diagnostically significant differences between echo-planar(More)
PURPOSE To investigate if primary cholesteatomas of the petrous bone show high signal in diffusion-weighted imaging (DWI). MATERIALS AND METHODS In this blinded study, we compared 15 patients with clinically certain cases and later surgically proven cholesteatomas vs. 12 patients with clinically acute otitis of the middle ear and 20 volunteers without(More)
Using event-related functional magnetic resonance imaging we investigated blood oxygen level dependent brain activation in spider phobic and non-phobic subjects while exposed to phobia-related pictures (spiders) and non-phobia-related pictures (snakes and mushrooms). In contrast to previous studies, we show significantly increased amygdala activation in(More)
We present the unique case of a patient with a circumscribed solitary cerebral metastasis of a malignant melanoma extending from the medial part of the superior temporal gyrus to the lower part of the 1st long insular gyrus causing gait and stance instability and an ipsiversive tilt of the subjective visual vertical. Oculomotor disorders could not be(More)