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...

An evaluation of two anthropomorphic breast phantoms, which have been designed for quality assurance and dose verification of radiotherapy treatment of breast cancer patients, is presented. These phantoms are identical in terms of their dimensions and shape, and composed of several layers of either Plastic Water or tissue-equivalent material. Both water- and tissue-equivalent phantoms include l...

The study of condition status and identification problems seagrass damage in the waters South Kayoa District, Halmahera Regency aims to determine ecosystem conditions identify Regency. Based on research results level Regency, about Decree Minister State for Environment no. 200 2004. station I (Pasir Putih) has an area ​​61.23 significant damage. Station II (Ngute-Ngute) 49.69 moderate III (Posi...

BACKGROUND AND OBJECTIVES Irradiation of whole blood and blood components before transfusion is currently the only accepted methodology to prevent transfusion-associated graft-vs.-host disease. In the present work, we developed an automated system for blood bag storage during irradiation, using a teletherapy unit. MATERIALS AND METHODS A device with two thermal compartments was constructed in...

Given a system (V, f, d) on a finite set V consisting of two set functions f : 2 → R and d : 2 → R, we consider the problem of finding a set R ⊆ V of minimum cardinality such that f(X) ≥ d(X) for all X ⊆ V − R, where the problem can be regarded as a natural generalization of the source location problems and the external network problems in (undirected) graphs and hypergraphs. We give a structur...

Dairy cream is shown to be a simple, inexpensive, isotropic phantom useful for testing diffusional kurtosis imaging data acquisition and postprocessing. The MR-visible protons of cream exhibit slow and fast diffusion components, attributed to the fat and water protons, respectively, which give rise to a diffusion coefficient of 1.1 μm(2)/ms and a diffusional kurtosis of 1.2. These parameter val...

In order to provide precision and objective image quality measures (IQMs) for the low dose CT (Computed Tomography) images, various general IQMs need to be validated and analyzed. The IQM based on Markov Random Field (MRF) has not been check and validated by a comprehensive distorted database. First choose a standard distorted image database of LIVE (Laboratory for Image & Video Engineering) to...

PURPOSE A performance comparison of film-screen combination used in mammography was conducted using conventional and new techniques. MATERIALS AND METHODS The performance of 30 mammographic film-screen combinations was evaluated by sensitometry, and the total performance was determined using phantom measurements. Quantum detection and light emission efficiency of the screens were also measure...

The arti…cial neural network (ANN) test of Lee, White and Granger (LWG, 1993) uses the ability of the ANN activation functions in the hidden layer to detect neglected functional misspeci…cation. As the estimation of the ANN model is often quite di¢ cult, LWG suggested activate the ANN hidden units based on randomly drawn activation parameters. To be robust to the random activations, a large num...