BACKGROUND In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2-2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically evaluated in NEMA IQ phantom measurements...

Using a mail-delivered questionnaire, we surveyed 590 veteran amputees concerning phantom pain, phantom sensation and stump pain. They were selected randomly from a population of 2974 veterans with long-standing limb amputation(s) using a computer random number generator. Eighty-nine percent responded and of these, 55% reported phantom limb pain and 56% stump pain. There was a strong correlatio...

This paper shows that the Camassa-Holm (CH) spectral problem yields two different integrable hierarchies of nonlinear evolution equations (NLEEs), one is of negative order CH hierachy while the other one is of positive order CH hierarchy. The two CH hierarchies possess the zero curvature representations through solving a key matrix equation. We find that the well-known CH equation is included i...

Relevant domain features are used for the representat ion of knowledge in production ru les and for the descr ipt ion of examples for ru le induct ion programs. A concept acqu is i t ion CCAS, induces domain concepts for the descr ip t ion of middle-game posi t ions in chess, and uses quan t i t a t i ve measures of information content for v a l i d a t i n g the acquired concepts.

introduction: in this study, arrangement of a low-cost optical tomography device compared to other methods such as frequency domain diffuse tomography or time domain diffuse tomography is reported. this low-cost diffuse optical imaging technique is based on the detection of light after propagation in tissue. these detected signals are applied to predict the location of in-homogeneities inside p...

introduction: nasopharyngeal carcinoma is one of the most common malignancies in the head and neck region and radiotherapy is its treatment of choice. in spite of the fact that it is widely used, due to the presence of many sensitive organs or tissues in this region, patients may suffer from a wide range of side effects. one such sensitive tissue is the spinal cord. if the absorbed dose to spin...