The impact of CT window settings on the contouring of a moving target: A phantom study

The current academic debate on the sharing economy (SE) seems to embrace three main discussions: its definition, its effects, and the role of regulation. A neglected topic here seems to be analyzing the specific implications of the changing nature of these firms boosted by private equity and venture capital. As the author points out, we need to analyze not only the impact of a changing business model but, specifically, how stakeholders, cities, and regulators should approach this moving target now called SE. In the following sections the author departs from a traditional definition of the sharing economy to start building the case for treating the SE at large as an epiphenomenon of the platform economy, and as a temporary condition based on a moveable business model. The chapter closes by introducing the regulatory hurdles that come associated with the previous and mapping out its different futures.

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Poster - Thurs Eve-41: Imaging and radiation delivery in helical tomotherapy: Phantom study of a moving target

Medical Physics ◽

10.1118/1.2965960 ◽

2008 ◽

Vol 35 (7Part3) ◽

pp. 3409-3409

Author(s):

C Gallagher ◽

S Yartsev ◽

J Van Dyk

Keyword(s):

Helical Tomotherapy ◽

Phantom Study ◽

Moving Target ◽

Radiation Delivery

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The Impact of Address Changes and Host Diversity on the Effectiveness of Moving Target Defense Strategy

2016 IEEE 40th Annual Computer Software and Applications Conference (COMPSAC) ◽

10.1109/compsac.2016.233 ◽

2016 ◽

Cited By ~ 6

Author(s):

Jianjun Zheng ◽

Akbar Siami Namin

Keyword(s):

Moving Target ◽

Moving Target Defense ◽

Defense Strategy ◽

Host Diversity ◽

The Impact

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Contrast enhancement in abdominal computed tomography: influence of photon energy of different scanners

British Journal of Radiology ◽

10.1259/bjr.20170285 ◽

2018 ◽

Vol 91 (1081) ◽

pp. 20170285 ◽

Cited By ~ 1

Author(s):

Narumi Taguchi ◽

Seitaro Oda ◽

Takeshi Nakaura ◽

Daisuke Utsunomiya ◽

Yoshinori Funama ◽

...

Keyword(s):

Clinical Study ◽

Contrast Enhancement ◽

Contrast Material ◽

Vena Cava ◽

Phantom Study ◽

Absolute Difference ◽

X Ray ◽

Abdominal Organs ◽

Ct Scanners ◽

The Impact

Objective: Different CT scanners have different X-ray spectra and photon energies indicating that contrast enhancement vary among scanners. However, this issue has not been fully validated; therefore, we performed phantom and clinical studies to assess this difference. Methods: Two scanners were used: scanner-A and scanner-B. In the phantom study, we compared the contrast enhancement between the scanners at tube voltage peaks of 80, 100 and 120 kVp. Then, we calculated the effective energies of the two CT scanners. In the clinical study, 40 patients underwent abdominal scanning with scanner-A and another 40 patients with scanner-B, with each group using the same scanning protocol. The contrast enhancement of abdominal organs was assessed quantitatively (based on the absolute difference between the attenuation of unenhanced scans and contrast-enhanced scans) and qualitatively. A two-tailed independent Student's t-test and or the Mann–Whitney U test were used to compare the discrepancies. Results: In the phantom study, contrast enhancement for scanner-B was 36.9, 32.6 and 30.8% higher than that for scanner-A at 80, 100 and 120 kVp, respectively. The effective energies were higher for scanner-A than for scanner-B. In the quantitative analysis for the clinical study, scanner-B yielded significantly better contrast enhancement of the hepatic parenchyma, pancreas, kidney, portal vein and inferior vena cava compared with that of scanner-A. The mean visual scores for contrast enhancement were also significantly higher on images obtained by scanner-B than those by scanner-A. Conclusion: There were significant differences in contrast enhancement of the abdominal organs between the compared CT scanners from two different vendors even at the same scanning and contrast parameters. Advances in knowledge: Awareness of the impact of different X-ray energies on the resultant attenuation of contrast material is important when interpreting clinical CT images.

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