The increasing availability of SPECT/CT devices with advanced technology offers the opportunity for the accurate assessment of the radiation dose to the biological target volume during radionuclide therapy. Voxel dosimetry can be performed employing direct Monte Carlo radiation transport simulations, based on both morphological and functional images of the patient. On the other hand, for voxel ...

Sensor networks are prone to congestion due to bursty and high-bandwidth data traffic, combined with many-to-one data routing to a sink. Delayed and dropped packets then degrade the performance of the sensing application. In this work, we investigate the value of separate handling of sensor control and data traffic, during times of congestion, in a networked sense-and-response system. We analyz...

BACKGROUND The benefits of a decreased slice thickness and/or in-plane voxel size in carotid MRI for atherosclerotic plaque component quantification accuracy and biomechanical peak cap stress analysis have not yet been investigated in detail because of practical limitations. METHODS In order to provide a methodology that allows such an investigation in detail, numerical simulations of a T1-we...

This paper presents a novel voxel-based method for texture analysis of brain images. Texture analysis is a powerful quantitative approach for analyzing voxel intensities and their interrelationships, but has been thus far limited to analyzing regions of interest. The proposed method provides a 3D statistical map comparing texture features on a voxel-by-voxel basis. The validity of the method wa...

Introduction: The forced expiratory flow at 25 and 75% of the pulmonary volume/forced vital capacity ratio (FEF25-75/FVC) as a spirometry parameter has been successful in the early diagnosis of chronic obstructive pulmonary disease (COPD) and the methacholine challenge test for assessing airway responsiveness.To determine the accuracy of FEF25-7...

BACKGROUND Commonly used methods of assessing the accuracy of deformable image registration (DIR) rely on image segmentation or landmark selection. These methods are very labor intensive and thus limited to relatively small number of image pairs. The direct voxel-by-voxel comparison can be automated to examine fluctuations in DIR quality on a long series of image pairs. METHODS A voxel-by-vox...

PURPOSE To describe our approach to mapping the functional information provided by single photon emission computed tomography (SPECT) onto the anatomic template provided by MR, and to determine both the number of markers required to achieve accuracy and the impact of voxel shape on accuracy. METHODS Point-to-point iterative minimization using externally fixed fiducial markers was involved and...

Purpose This work examines an extension of an entropy based non-rigid registration algorithm to recover very localised sub-voxel distortion of EPI data relative to high-resolution anatomical MRI. Such a registration estimate can then be used to provide increased accuracy of the anatomical localisation of fMRI activations. Introduction Accurate alignment of fMRI data with high-resolution anatomi...

The mesoscale variability of water vapour (WV) in the troposphere is a highly complex phenomenon and modelling and monitoring the WV distribution is a very important but challenging task. Any observation technique that can reliably provide WV distribution is essential for both monitoring and predicting weather. The global navigation satellite system (GNSS) tomography technique is a powerful too...