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 ...

A software tool is presented to measure the geometric distortion in images obtained with X-ray systems that provides a more objective method than the usual measurements over the image of a phantom with usual rulers. In a first step, this software has been applied to mammography images and makes use of the grid included into the CDMAM phantom (University Hospital Nijmegen). For digital images, t...

We propose a novel test object for ultrasound imaging. The test object, or phantom, is manufactured using thin film techniques allowing precise placement of 'digital scatterers' which can produce sophisticated test targets, similar to those that are widely used in imaging science to evaluate displays, printers and electronic imaging systems. These test objects can be used in conjunction with st...

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...

This paper reports on a further development of an image simulation chain, and in particular, the inclusion of contrast degradation across an image using scatter to primary ratios calculated using Monte Carlo simulation. The Monte Carlo technique, using the Geant4 toolkit, has been implemented to model the scatter conditions when imaging the CDMAM phantom with commercial digital mammography. Obs...

Hyperion-II(D) is a positron emission tomography (PET) insert which allows simultaneous operation in a clinical magnetic resonance imaging (MRI) scanner. To read out the scintillation light of the employed lutetium yttrium orthosilicate crystal arrays with a pitch of 1 mm and 12 mm in height, digital silicon photomultipliers (DPC 3200-22, Philips Digital Photon Counting) (DPC) are used. The bas...

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...

This study is motivated by the physical modeling of the longitudinal string vibrations in the piano. Informal listening tests show that the longitudinal vibrations play an important role in the attack of the sound, and are responsible for the metallic character of low notes. First, a simple mathematical model is developed for qualitative understanding. Detailed analysis is given for sinusoidal ...

A novel deformable registration algorithm is proposed in the application of radiation therapy. The algorithm starts with autodetection of a number of points with distinct tissue features. The feature points are then matched by using the scale invariance features transform (SIFT) method. The associated feature point pairs are served as landmarks for the subsequent thin plate spline (TPS) interpo...