PURPOSE In longitudinal oncological and brain PET/CT studies, it is important to understand the repeatability of quantitative PET metrics in order to assess change in tracer uptake. The present studies were performed in order to assess precision as function of PET/CT system, reconstruction protocol, analysis method, scan duration (or image noise), and repositioning in the field of view. METHO...

The purpose of this study is to characterize the x-ray properties of a dual-modality, anthropomorphic breast phantom whose MRI properties have been previously evaluated. The goal of this phantom is to provide a platform for optimization and standardization of two- and three-dimensional x-ray and MRI breast imaging modalities for the purpose of lesion detection and discrimination. The phantom is...

introduction:  the  purpose  of  this  study  is  to  define  the  optimal  parameters  for  the  tomographic  reconstruction procedure in a routine single photon emission tomography. the hoffman brain phantom  is modified to evaluate the reconstruction method. the phantom was imaged in a 3 and 2-dimensional  conformation and the results were compared.   materials  and  methods:  the  2d  phant...

introduction accurate estimation of the absorbed dose in radiosensitive organs, located away from the target volume during radiotherapy, is one of the main reasons for the development of reference phantoms. the international commission on radiological protection (icrp) reference phantoms can provide a more realistic view of the human anatomy in comparison with the previously used mathematical p...

We examine cosmological models with generalized phantom energy (GPE). Generalized phantom energy satisfies the supernegative equation of state, but its evolution with the scale factor is generally independent, i.e. not determined by its equation of state. The requirement of general covariance makes the gravitational constant time-dependent. It is found that a large class of distinct GPE models ...

Phantom types are data types with type constraints associated with different cases. Examples of phantom types include typed type representations and typed higher-order abstract syntax trees. These types can be used to support typed generic functions, dynamic typing, and staged compilation in higher-order, statically typed languages such as Haskell or Standard ML. In our system, type constraints...

Computed Tomography (CT) and Magnetic Resonance (MR) imaging techniques have become an important role in diagnosing the vascular diseases. Before a clinical trial of the newly developed techniques, it is essential to evaluate them on a phantom. However, there is no existing arterial A Dynamic Arterial Tree Phantom for studies 89 tree phantom that serves for flood flows. To that end, we design a...

Phantom limb pain affects an alarming amount of amputees. Little is known about the true cause of phantom limb pain, making it difficult to establish a standard treatment for it. This literature review looks at the etiology of phantom limb pain as well as the three major forms of treatment for phantom limb pain: pharmacological, invasive, and supportive. These three forms of treatment use diffe...

A digital brain phantom was created from available primate autoradiographic (AR) data for use in emission computed tomography studies. The tissue was radio-labelled with a functional analogue of the PET agent [18F]-fluoro-deoxyglucose (FDG). Following sacrifice of the animal, film records from serial 20 m thickness sections were digitized and calibrated to obtain ground truth 2D spatial distrib...

Introduction. Perfusion describes the rate of delivery of arterial blood to the parenchymal tissue and is a valuable physiological parameter for detection of ischemia and function. Most imaging modalities provide methodology for perfusion evaluation with varying degrees of accuracy and reproducibility [1], typically using a tracer in the blood or even the blood itself as in spin labeling techni...