P. J. M. Folkers

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Diffusion-tensor MR imaging of the brain is an objective method that can measure diffusion of water in tissue noninvasively. Five adult volunteers participated in this study that was performed to evaluate the potential of gradient- and spin-echo readout for diffusion-tensor imaging by comparing it with single-shot spin-echo echo-planar imaging. Gradient-(More)
Motion poses severe problems for BOLD fMRI, particularly in clinical studies, as patients exhibit more involuntary movements than controls. This study focuses on the merits of a motion correction technique incorporated in multishot fMRI scans, so-called phase navigator correction. The technique entails real-time assessment and off-line elimination of signal(More)
A new ultrafast MR imaging method is proposed and tested, which enables whole-brain fMRI with a true temporal resolution of 1 sec. The method combines a 3D PRESTO pulse sequence with the concept of sensitivity-encoding with multiple receiver coils (SENSE). The so-called PRESTO-SENSE technique is demonstrated on a set of functional block-type motor and(More)
PURPOSE To describe the radiologic findings of susceptibility changes in acute middle cerebral artery (MCA) thromboembolism detected with three-dimensional (3D) susceptibility-based perfusion magnetic resonance (MR) imaging and to compare the detectability and clinical value of this sign with those of the hyperdense MCA sign at computed tomography (CT). (More)
PURPOSE To evaluate the differentiation of benign from malignant breast tumors with T2*-weighted perfusion magnetic resonance (MR) imaging (blood volume imaging) versus that with dynamic T1-weighted contrast agent-enhanced MR imaging. MATERIALS AND METHODS Ten healthy adult volunteers and 18 adult patients with benign or malignant lesions underwent both(More)
In this study, we investigated differences between gray matter and white matter perfusion in patients with a unilateral occlusion of the internal carotid artery (ICA) with dynamic susceptibility contrast. Seventeen patients and 17 control subjects were studied, using T2*-weighted gradient echo acquisition. Gray and white matter regions were obtained by(More)
Author contributions: Guarantor of integrity of entire study, E.R.M.; study concepts and design, E.R.M.; definition of intellectual content, E.R.M.; literature research, E.R.M.; clinical studies, E.R.M.; data acquisition, E.R.M., R.I.; data analysis, E.R.M., R.I.; manuscript preparation, E.R.M., R.I.; manuscript editing, E.R.M., R.I., P.J.M.F.; manuscript(More)
The solution structure of recombinant wild-type hirudin and of the putative active site mutant Lys-47----Glu has been investigated by nuclear magnetic resonance (NMR) spectroscopy at 600 MHz. The 1H NMR spectra of the two hirudin variants are assigned in a sequential manner with a combination of two-dimensional NMR techniques. Some assignments made in our(More)
We sought to evaluate a three-dimensional (3D) whole-brain perfusion technique based on echo-shifting (PRESTO) for its performance in evaluation of acute stroke. Twenty-six patients were scanned within 6 hours after onset of hemispheric symptoms, and the results were compared with results of diffusion-weighted imaging (DWI) and digital subtraction(More)
PURPOSE To evaluate the feasibility and the diagnostic efficacy of multislice diffusion-weighted and perfusion imaging in addition to FLAIR-TSE, T2w-GraSE and MR-angiography in the diagnosis of acute stroke. METHODS 18 patients with acute stroke were examined at 1.5 Tesla (Gyroscan ACS-NT, Philips Medical Systems) within 6 (n = 9) and 6-48 (n = 9) hours,(More)