Uncertainty in arterial input function (AIF) estimation is one of the major errors in the quantification of dynamic contrast-enhanced MRI. A blind source separation algorithm was proposed to determine the AIF by selecting the voxel time course with maximum purity, which represents a minimal contamination from partial volume effects. Simulations were performed to assess the partial volume effect...

Adaptive optical lenses based on the electrowetting principle are being rapidly implemented in many applications, such as microscopy, remote sensing, displays, and optical communication. To characterize the response of these electrowetting lenses, the dependence upon direct current (DC) driving voltage functions was investigated in a low-viscosity liquid system. Cylindrical lenses with inner di...

PURPOSE To validate a new method for converting MR arterial signal intensity versus time curves to arterial input functions (AIFs). MATERIALS AND METHODS The method constrains AIF with patient's cardiac output (Q). Monte Carlo simulations of MR renography and tumor perfusion protocols were carried out for comparison with two alternative methods: direct measurement and population-averaged inpu...

Introduction DCE-MRI has been widely used at 1.5T in a variety of organs and tissues. The aim of this study was to assess the feasibility of DCE-MRI in the liver at 3T, taking into account the challenges of 3T systems, and performed in such a way as to allow a dual-input pharmacokinetic analysis, separating the perfusion contributions from the hepatic artery and portal vein. To our knowledge, t...

This paper addresses the issue of Software Cost Estimation (SCE) providing an alternative approach to modelling and prediction using Artificial Neural Networks (ANN) and Input Sensitivity Analysis (ISA). The overall aim is to identify and investigate the effect of the leading factors in SCE, through ISA. The factors identified decisively influence software effort in the models examined and thei...

The way in which single neurons transform input into output spike trains has fundamental consequences for network coding. Theories and modeling studies based on standard Integrate-and-Fire models implicitly assume that, in response to increasingly strong inputs, neurons modify their coding strategy by progressively reducing their selective sensitivity to rapid input fluctuations. Combining math...

The need for achieving higher data rates in underwater acoustic communications leverages the use of multi-input multi-output (MIMO) schemes. In this paper two key issues regarding the design of a MIMO communications system, namely, channel estimation and symbol detection, are addressed. To enhance channel estimation performance, a cyclic approach for designing training sequences and a channel e...

A long debate in selective attention research is whether attention enhances sensory response or sharpens neural tuning by suppressing response to non-target input. In fact, both processes may occur as a function of load: an uncertain listener might use a broad attentional filter to enhance responses to all inputs (i.e., vigilance), yet employ sharpened tuning to focus on hard to discriminate ta...

BACKGROUND The present study determines the feasibility of generating an average arterial input function (Avg-AIF) from a limited population of patients with neck nodal metastases to be used for pharmacokinetic modeling of dynamic contrast-enhanced MRI (DCE-MRI) data in clinical trials of larger populations. METHODS Twenty patients (mean age 50 years [range 27-77 years]) with neck nodal metas...

Epidemiological and experimental studies underline the role of magnesium in inflammation. Several data indicate an enhanced response of phagocytes (granulocytes, macrophages) derived from magnesium-deficient animals or cultured under low magnesium conditions to the inflammatory mediators' stimulation. On the contrary, it was pointed out that high extracellular Mg2+ concentration might partially...