introduction: due to the large number of pet systems available in the market, it is not very easy to decide about the scanner of choice. conducting a research in order to compare all different pet scanners is very time consuming and expensive and practically impossible. however, such comparison may be conducted using pet simulators. in this study, the performance of 6 different pet scanners in ...

—Continued on Pg. 2 The new Preservation Group (PG) experiment will provide answers for cash-strapped state and local agencies that need cost-effective ways to maintain existing asphalt roadways. Budgets are tight, but agencies still have the same task: keeping aging pavements in good condition for the driving public. When applied at the right time, pavement preservation treatments, such as chi...

UNLABELLED Myocardial perfusion gated-single photon emission computed tomography (gated-SPECT) imaging is used for the combined evaluation of myocardial perfusion and left ventricular (LV) function. The aim of this study is to analyze the influence of counts/pixel and concomitantly the total counts in the myocardium for the calculation of myocardial functional parameters. MATERIAL AND METHODS...

PURPOSE This work is a preliminary study of a stationary cardiac SPECT system. The goal of this research is to propose a stationary cardiac SPECT system using segmented slant-hole collimators and to perform computer simulations to test the feasibility. Compared to the rotational SPECT, a stationary system has a benefit of acquiring temporally consistent projections. The most challenging issue i...

The interest of PET complementary information for the delineation of the target volume in radiotherapy of lung cancer is increasing. However, respiratory motion requires the determination of a functional internal target volume (ITV) on PET images for which several strategies have been proposed. The purpose of this study was the comparison of these strategies for taking into account respiratory ...

Experimental economists currently lack a convention for how to pay subjects in experiments with multiple tasks. We provide a theoretical framework for analyzing this question. Assuming monotonicity (dominated gambles are never chosen) and nothing else, we prove that paying for one randomly-chosen problem—the random problem selection (RPS) mechanism—is (usually) the only incentive compatible mec...

background: the heterogeneous composition of the human body presents numerous tissue types and cavities with widely differing radiologic properties. the aim of the present work was to develop a low cost homogeneous and heterogeneous phantom and the absorbed dose were measured by ionization chamber for different radiotherapy treatment techniques and compared with treatment planning system absorb...

background long-term clinical symptoms and functional status of above-knee amputees are not well documented. this study documents the long-term outcomes of war related above-knee amputations. objective to study the long-term outcomes of unilateral above-knee amputation. materials and methods the study consisted of a comprehensive assessment, examination, and review of history and wartime medica...

introduction based on task group no. 43 (tg-43u1) recommendations, water phantom is proposed as a reference phantom for the dosimetry of brachytherapy sources. the experimental determination of tg-43 parameters is usually performed in water-equivalent solid phantoms. the purpose of this study was to determine the conversion factors for equalizing solid phantoms to water. materials and methods t...

Gated cardiac SPECT imaging has been widely used in the evaluation of cardiac functions. The acquired fourdimensional (4D) sinogram data have both inter-frame correlation among the time sequence and intra-frame correlation within each 3D frame. The unique features of Karhune-Loève (KL) transform for de-correlating the data sequence for noise reduction, feature extraction, etc, have been well re...