نتایج جستجو برای: digital ncat phantom

تعداد نتایج: 324200  

Behzad Mohsenzadeh, Fereshte Rahmani Hamed Bagheri Khatereh Shamsi Leila Azimi Mohammad Reza Deevband, Zeinab Kaveh

Introduction: This study, evaluate pediatric digital radiography. Due to the high rates of this test and the high sensitivity of children to ionizing radiation in comparison with adults, it is attempted to achieve near optimal conditions by reducing the dose and maintaining the image quality. The object of the study is to change the irradiation parameters such as kV and mA and ...

2005
Monte Symons

In addition to lower emissions warm mix asphalt has several advantages over hot mix asphalt such as fuel energy savings, decreased binder aging and an extended paving season (Photo courtesy: Matthew Corrigan, FHWA) The National Center for Asphalt Technology (NCAT) is evaluating warm mix asphalt (WMA) technologies. WMA technology allows the mixing, lay down, and compaction of asphalt mixes at si...

Journal: :Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society 2014
Fotis A. Kotasidis Charalampos Tsoumpas Irene Polycarpou Habib Zaidi

INTRODUCTION Dynamic image acquisition protocols are increasingly used in emission tomography for drug development and clinical research. As such, there is a need for computational phantoms to accurately describe both the spatial and temporal distribution of radiotracers, also accounting for periodic and non-periodic physiological processes occurring during data acquisition. METHODS A new 5D ...

2014
Lesley Cockmartin Predrag R. Bakic Hilde Bosmans Andrew D. A. Maidment Hunter Gall Moustafa Zerhouni Nicholas Marshall

Digital breast tomosynthesis (DBT) images of a novel anthropomorphic breast phantom (UPenn phantom) acquired on two breast tomosynthesis systems were analyzed in terms of their power spectra (PS). The β and κ power law coefficients were estimated from 2D planar, tomosynthesis projection images and reconstructed planes. These data were compared to the PS characteristics as retrieved from a group...

Journal: :Nihon Hoshasen Gijutsu Gakkai zasshi 2006
Miwa Okumura Takamasa Ota Shinsuke Tsukagoshi Kazuhiro Katada

To evaluate the characteristics of edge-preserving adaptive filters for selectively eliminating noise without affecting resolution in low-dose scanning, we have developed a digital phantom image and evaluated noise statistical values, noise characteristics, and resolution characteristics. The results confirmed that edge-preserving adaptive filters function as smoothing filters in low-contrast r...

Journal: :Revue d'anthropologie des connaissances 2019

Journal: :Physics in medicine and biology 2004
Jerry Wong Tong Xu Adeel Husain Huy Le Sabee Molloi

In mammography, thick or dense breast regions persistently suffer from reduced contrast-to-noise ratio (CNR) because of degraded contrast from large scatter intensities and relatively high noise. Area x-ray beam equalization can improve image quality by increasing the x-ray exposure to under-penetrated regions without increasing the exposure to other breast regions. Optimal equalization paramet...

Journal: :Radiological physics and technology 2013
Satoru Utsunomiya Hajime Monzen Mami Akimoto Nobutaka Mukumoto Yoshitomo Ishihara Takehiko Shiinoki Mitsuhiro Nakamura Yuki Miyabe Sayaka Sato Satoru Matsuo Masahiro Hiraoka

We investigated the neonatal entrance-surface dose (ESD) and doses of scattered radiation emitted by a digital mobile X-ray system. The system is equipped with a novel flat-panel detector and is used in the neonatal intensive care unit. In the present study, the following three experiments were performed on frequently used X-ray-imaging condition: (1) the digital characteristics of the FPD were...

2013
Saeed Seyyedi Kubra Cengiz Mustafa E. Kamasak Isa Yildirim

Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to...

Journal: :Nihon Hoshasen Gijutsu Gakkai zasshi 2013
Mitsuyoshi Yasuda Kyoichi Kato Syun Kurosawa Kohki Yoshikawa Hisaya Sato Toshiyuki Takahashi Tugunori Iwai Hiroyuki Watanabe Yasuo Nakazawa

We noted that breast-like artifacts occur in photo-stimulable phosphor plates (PSPs) used for long periods in digital mammography systems. This prompted us to investigate the effects on mammography diagnoses of these artifacts. Our study took the form of a comparison between the images generated by a long-term use PSP (four years use) and a short-term use PSP. First, an acrylic phantom and an i...

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