Jacobus F. A. Jansen

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Hydrogen 1 (1H) magnetic resonance (MR) spectroscopy enables noninvasive in vivo quantification of metabolite concentrations in the brain. Currently, metabolite concentrations are most often presented as ratios (eg, relative to creatine) rather than as absolute concentrations. Despite the success of this approach, it has recently been suggested that(More)
OBJECTIVE To study the relation between possibly altered whole brain topology and intellectual decline in chronic epilepsy, a combined study of neurocognitive assessment and graph theoretical network analysis of fMRI was performed. METHODS Forty-one adult patients with cryptogenic localization-related epilepsy and 23 healthy controls underwent an(More)
Advances in computational network analysis have enabled the characterization of topological properties in large scale networks including the human brain. Information on structural networks in the brain can be obtained in-vivo by performing tractography on diffusion tensor imaging (DTI) data. However, little is known about the reproducibility of network(More)
OBJECTIVES The reproducibility of quantitative cerebral T2 relaxometry, diffusion tensor imaging, and H magnetic resonance (MR) spectroscopic imaging was assessed on a clinical 3.0 T MR system. MATERIALS AND METHODS Repeated measurements in 10 healthy volunteers were used to establish the reproducibility of quantitative measures derived from different(More)
PURPOSE To correlate proton magnetic resonance spectroscopy ((1)H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and (18)F-labeled fluorodeoxyglucose positron emission tomography ([(18)F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally,(More)
Patients with chronic epilepsy frequently display cognitive comorbidity and might have widespread network abnormalities outside the epileptic zone, which might affect a variety of cognitive functions and global intelligence. We aimed to study the role of white matter connectivity in cognitive comorbidity. Thirty-nine patients with nonsymptomatic(More)
PURPOSE Dynamic contrast-enhanced MRI (DCE-MRI) can provide information regarding tumor perfusion and permeability and has shown prognostic value in certain tumors types. The goal of this study was to assess the prognostic value of pretreatment DCE-MRI in head and neck squamous cell carcinoma (HNSCC) patients with nodal disease undergoing chemoradiation(More)
In the context of neuroimaging experiments, it is essential to account for the multiple comparisons problem when thresholding statistical mappings. Various methods are in use to deal with this issue, but they differ in their signal detection power for small- and large-scale effects. In this paper, we comprehensively describe a new method that is based on(More)
BACKGROUND An often underestimated cognitive morbidity in patients with epilepsy is language dysfunction. To investigate the neuronal mechanisms underlying neuropsychological language impairment, activation maps and functional connectivity networks were studied by fMRI of language. METHOD Fifty-two patients with cryptogenic localization-related epilepsy(More)
PURPOSE To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by (18)F-fluoromisonidazole ((18)F-FMISO) positron emission tomography (PET). (More)