PURPOSE This study was a systematic evaluation across different and prominent diffusion MRI models to better understand the ways in which scalar metrics are influenced by experimental factors, including experimental design (diffusion-weighted imaging [DWI] sampling) and noise. METHODS Four diffusion MRI models-diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), mean apparent pro...

A method of performing diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) of the fetal brain in utero is proposed. The major difficulty of performing diffusion imaging in utero is the presence of motion. By modifying conventional single-shot spin-echo echo-planar DWI with a short repetition time sequence, a sequence that performs DWI and DTI within a breath-hold of the mother (...

BACKGROUND AND PURPOSE Diffusion-weighted MR imaging of the spine has been used to differentiate benign from pathologic vertebral body compression fractures. We sought to determine the utility of diffusion-weighted MR imaging in the detection of vertebral metastases and to compare it with conventional noncontrast T1- and T2-weighted MR imaging. METHODS Fifteen patients with metastases to the ...

In 1988 Ronald R. Yager [14] introduced a new aggregation technique based on the ordered weighted averaging (OWA) operators. The goal of this paper is to present a short survey of of OWA operators and illustrate their applicability by a real-life example.

BACKGROUND Geographically weighted regression (GWR) is a modelling technique designed to deal with spatial non-stationarity, e.g., the mean values vary by locations. It has been widely used as a visualization tool to explore the patterns of spatial data. However, the GWR tends to produce unsmooth surfaces when the mean parameters have considerable variations, partly due to that all parameter es...

Previously, we introduced the best-expert problem, and we proved a O(ln K) mistake bound for the majority vote algorithm when a perfect expert exists, i.e., there is an expert that never makes mistakes. Now let us turn to the more realistic case where there is no perfect expert among the committee. We extend the majority vote algorithm with a confidence weight. At each round, we maintain a weig...

background: the purpose of this study is to demonstrate the advantages of gradient echo (gre) sequences in the detection and characterization of cerebral venous sinus thrombosis compared to conventional magnetic resonance sequences. methods: a total of 17 patients with cerebral venous thrombosis (cvt) were evaluated using different magnetic resonance imaging (mri) sequences. the mri sequences i...

The application of geographically weighted regression (GWR) - a local spatial statistical technique used to test for spatial nonstationarity - has grown rapidly in the social, health and demographic sciences. GWR is a useful exploratory analytical tool that generates a set of location-specific parameter estimates which can be mapped and analysed to provide information on spatial nonstationarity...

BACKGROUND AND PURPOSE Some investigators have proposed that either calculated diffusion trace images or apparent diffusion coefficient (ADC) maps, which require imaging with multiple diffusion sensitivities and/or postacquisition image processing, are essential for the accurate interpretation of diffusion-weighted images in acute stroke because of the possible pitfalls of regional diffusion an...

Ecological security is an important research topic, especially urban ecological security. As highly populated eco-systems, cities always have more fragile ecological environments. However, most of the research on urban ecological security in literature has focused on evaluating current or past status of the ecological environment. Very little literature has carried out simulation or prediction ...