Introduction: Geometric distortion is a major shortcoming of magnetic resonance imaging (MRI), which has an important influence on the accuracy of volumetric measurements, an important parameter in neurology and oncology. Our goal is to design and construct a new three- dimensional phantom using a 3D printer in order to measure geometric distortion and its reproducibility in...

Re-distancing the implicit surface is time-consuming. We propose a fast implementation of the Chamfer distance which maintains the sub-voxel accuracy of the interface. This approximation to the Euclidean distance gives a reasonable accuracy while improving considerably the computation time.

conclusion considering the similar diagnostic efficacy of all voxel sizes, 300 µm voxel size can be used with adequate efficacy for detection of external root resorption defects with minimal patient radiation dose and the shortest scanning time. background selecting a voxel size that yields minimal radiation dose with no significant compromise of the diagnostic accuracy of cone beam computed to...

objectives: this study sought to assess the diagnostic accuracy of cone beam computed tomography (cbct) with different voxel sizes and intraoral digital radiography with photostimulable phosphor (psp) plate for detection of periapical (pa) bone lesions. materials and methods: in this ex vivo diagnostic study, one-millimeter defects were created in the alveolar sockets of 15 bone blocks, each wi...

We present a new model for fanning and bending white matter structures on a sub-voxel scale. We devise a parametric model of how the fibre orientation varies spatially over each sub-voxel in the voxel grid for both types of configuration. Fitting the model provides quantitative information about the degree of fanning or bending in each voxel. We demonstrate using data from a standard human brai...

Abstract Aim Single-voxel spectroscopy (SVS) discriminates amongst brain tumours by measuring metabolite variations reflective of malignant transformation. However, spectral contamination may affect diagnostic accuracy, impacting radiological opinion regions interest (ROI) required to determine extent surgical resection. Method A single-centre, retrospective, observational study, including 93 S...

This paper will examine the current chamfer and vector distance transforms for encoding objects as distance elds. A new vector distance transform is introduced which uses the city-block chamfer distance transform as a basis. Detailed error analysis using real CT data is presented demonstrating the improved accuracy the new approach gives over existing methods. The production of a sub-voxel accu...

Introduction In vivo three-dimensional (3D) kinematics of the ankle joint is essential for a better understanding of its biomechanics and for many clinical applications. Several measurement techniques are available for this data, but few allow non-invasive measurements with sub-millimetre accuracy. The purposes of the study were to develop further a voxel-based 2D to 3D registration method [1] ...

The ability to model objects composed of multiple materials has become increasingly more demanded in scientific applications. The visualization of a discrete multi-material volume often suffers from voxelization of the boundary between materials. We propose a contouring method that can be efficiently implemented on the GPU to reduce the artifacts and jaggedness along the material boundaries. Ou...