نتایج جستجو برای: ctdi

تعداد نتایج: 191  

2016
Masanao Kobayashi Yasuki Asada Kosuke Matsubara Shouichi Suzuki Kichiro Koshida Yuta Matsunaga Tomonobu Haba Ai Kawaguchi Hiroshi Toyama Ryoichi Kato

The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), prospective CTA, continuous CTA/cardiac function analysis (CFA), and CTA/CFA m...

2012
Dandan Zheng Jun Lu Ariel Jefferson Cheng Zhang Jian Wu William Sleeman Elisabeth Weiss Nesrin Dogan Shiyu Song Jeffrey Williamson

The longitudinal coverage of a LINAC-mounted CBCT scan is limited to the corresponding dimensional limits of its flat panel detector, which is often shorter than the length of the treatment field. These limits become apparent when fields are designed to encompass wide regions, as when providing nodal coverage. Therefore, we developed a novel protocol to acquire double orbit CBCT images using a ...

Journal: :Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics 2012
M A Habibzadeh M R Ay A R Kamali Asl H Ghadiri H Zaidi

The operation of the bowtie filter in x-ray CT is correct if the object being scanned is properly centered in the scanner's field-of-view. Otherwise, the dose delivered to the patient and image noise will deviate from optimal setting. We investigate the effect of miscentering on image noise and surface dose on three commercial CT scanners. Six cylindrical phantoms with different size and materi...

2016
Robert D. MacDougall Patricia L. Kleinman Michael J. Callahan

Size-based diagnostic reference ranges (DRRs) for contrast-enhanced pediatric abdominal computed tomography (CT) have been published in order to establish practical upper and lower limits of CTDI, DLP, and SSDE. Based on these DRRs, guidelines for establishing size-based SSDE target levels from the SSDE of a standard adult by applying a linear correction factor have been published and provide a...

2016
Heloise Barras Vincent Dunet Anne-Lise Hachulla Jochen Grimm Catherine Beigelman-Aubry

BACKGROUND Model-based iterative reconstruction (MBIR) reduces image noise and improves image quality (IQ) but its influence on post-processing tools including maximal intensity projection (MIP) and minimal intensity projection (mIP) remains unknown. PURPOSE To evaluate the influence on IQ of MBIR on native, mIP, MIP axial and coronal reformats of reduced dose computed tomography (RD-CT) ches...

Objective(s): Size specific dose estimate (SSDE) is a new parameter that includes patient size factor in its calculation. Recent studies have produced mixed results on the utility of SSDE, especially when automatic exposure control (AEC) was used. The objective of the study was to find out if there is a relationship between patient size and each of the parameters, SSDE...

Journal: :Physics in medicine and biology 2016
G Mettivier C Fedon F Di Lillo R Longo A Sarno G Tromba P Russo

The purpose of this work is to provide an evaluation of the mean glandular dose (MGD) for breast computed tomography (CT) with synchrotron radiation in an axial scanning configuration with a partial or total organ volume irradiation, for the in vivo program of breast CT ongoing at the ELETTRA facility (Trieste, Italy). A Geant4 Monte Carlo code was implemented, simulating the photon irradiation...

2016
Bastian O. Sabel Kristijan Buric Nora Karara Kolja M. Thierfelder Julien Dinkel Wieland H. Sommer Felix G. Meinel Chin-Tu Chen

OBJECTIVES To investigate the feasibility of high-pitch CT pulmonary angiography (CTPA) in 3rd generation dual-source CT (DSCT) in unselected patients. METHODS Forty-seven patients with suspected pulmonary embolism underwent high-pitch CTPA on a 3rd generation dual-source CT scanner. CT dose index (CTDIvol) and dose length product (DLP) were obtained. Objective image quality was analyzed by c...

2015
Lei Huang Zhaoxin Wang Yuhong Yao Chang Shan Haojie Wang Mengyi Zhu Yuan Lu Pengfei Sun Xudong Zhao

BACKGROUND Critical thinking is an essential ability for medical students. However, the relationship between parental rearing styles and medical students' critical thinking disposition has rarely been considered. The aim of this study was to investigate whether parental rearing styles were significant predictors of critical thinking disposition among Chinese medical students. METHODS 1,075 me...

Journal: :Physics in medicine and biology 2010
H Schlattl M Zankl J Becker C Hoeschen

Automatic tube current modulation (TCM) is used in modern CT devices. This is implemented in the numerical calculation of dose conversion coefficients for CT examinations. For four models of adults, the female and male reference models of ICRP and ICRU and a lighter and a heavier female model, dose conversion coefficients normalized to CTDI(vol) (DCC(CT)) have been computed with a Monte Carlo t...

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