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The most widely used task functional magnetic resonance imaging (fMRI) analyses use parametric statistical methods that depend on a variety of assumptions. In this work, we use real resting-state data and a total of 3 million random task group analyses to compute empirical familywise error rates for the fMRI software packages SPM, FSL, and AFNI, as well as(More)
We present a method for fast phase based registration of volume data for medical applications. As the number of different modalities within medical imaging increases, it becomes more and more important with registration that works for a mixture of modalities. For these applications the phase based registration approach has proven to be superior. Today there(More)
The validity of parametric functional magnetic resonance imaging (fMRI) analysis has only been reported for simulated data. Recent advances in computer science and data sharing make it possible to analyze large amounts of real fMRI data. In this study, 1484 rest datasets have been analyzed in SPM8, to estimate true familywise error rates. For a familywise(More)
The outflow conductance (C(out)) of the cerebrospinal fluid (CSF) system is a parameter considered to be predictive in selection for hydrocephalus surgery. C(out) can be determined through an infusion test. A new apparatus for performing infusion tests in a standardized and automated way was developed. The objective was to evaluate repetitiveness as well as(More)
PURPOSE For diagnostic purposes and for follow-up after treatment, it is important to have simple and reliable methods for measuring intraocular pressure (IOP). The purpose of this study was to develop a new applanation method for IOP measurement that uses combined continuous force and area measurement and to develop and evaluate an applanation resonator(More)
Graphics processing units (GPUs) are used today in a wide range of applications, mainly because they can dramatically accelerate parallel computing, are affordable and energy efficient. In the field of medical imaging, GPUs are in some cases crucial for enabling practical use of computationally demanding algorithms. This review presents the past and present(More)
OBJECT There are several infusion methods available to estimate the outflow conductance (Cout) or outflow resistance (Rout=1/Cout) of the CSF system. It has been stated that for unknown reasons, the bolus infusion method estimates a higher C(out) than steady-state infusion methods. The aim of this study was to compare different infusion methods for(More)
The brain and the spinal cord are contained in a cavity and are surrounded by cerebrospinal fluid (CSF), which provides physical support for the brain and a cushion against external pressure. Hydrocephalus is a disease, associated with disturbances in the CSF dynamics, which can be surgically treated by inserting a shunt or third ventriculostomy. This(More)
OBJECTIVE The intracranial pressure (ICP) and CSF outflow resistance (R(out)) are essential to describe the dynamics of the CSF system. R(out) affects ICP, pulse amplitudes, CSF absorption, and the compliance of the system. The objective of this study was to determine the reference values in healthy elderly subjects. METHODS Elderly people (60-82 years),(More)
The dynamic effects of continuous exposure to light on the neuronal adaptive system of the retina, as indicated by the oscillatory response (OPs) of the electroretinogram (ERG) were studied in the albino rat. Digitally filtered OPs and the a- and b-waves of the corneal ERG were simultaneously recorded in dark adaptation, during continuous light adaptation(More)