MCNP-FBSM: Development of MCNP/MCNPX Source Model for Simulation of Multi-Slice Fan-Beam X-Ray CT Scanners

2019 ◽  
Author(s):  
Hamidreza Khodajou-Chokami ◽  
Seyed Abolfazl Hosseini ◽  
Mohammad Reza Ay ◽  
Habib Zaidi
Keyword(s):  
Source Model ◽  
X Ray ◽  
Ct Scanners

scholarly journals Testing a double AGN hypothesis for Mrk 273

2018 ◽  
Vol 611 ◽  
pp. A71 ◽  
Author(s):  
K. Iwasawa ◽  
V. U ◽  
J. M. Mazzarella ◽  
A. M. Medling ◽  
D. B. Sanders ◽  
...  
Keyword(s):  
Alternative Explanation ◽  
Source Model ◽  
Spectral Slope ◽  
Line Flux ◽  
Ionized Gas ◽  
X Ray ◽  
Gas Kinematics ◽  
N Source ◽  
Seyfert Nucleus ◽  
Luminous Infrared Galaxy

The ultra-luminous infrared galaxy (ULIRG) Mrk 273 contains two infrared nuclei, N and SW, separated by 1 arcsecond. A Chandra observation has identified the SW nucleus as an absorbed X-ray source with NH ~ 4 × 1023 cm−2 but also hinted at the possible presence of a Compton-thick AGN in the N nucleus, where a black hole of ~109 M⊙ is inferred from the ionized gas kinematics. The intrinsic X-ray spectral slope recently measured by NuSTAR is unusually hard (Γ ~ 1.3) for a Seyfert nucleus, for which we seek an alternative explanation. We hypothesize a strongly absorbed X-ray source in N, of which X-ray emission rises steeply above 10 keV, in addition to the known X-ray source in SW, and test it against the NuSTAR data, assuming the standard spectral slope (Γ = 1.9). This double X-ray source model gives a good explanation of the hard continuum spectrum, deep Fe K absorption edge, and strong Fe K line observed in this ULIRG, without invoking the unusual spectral slope required for a single source interpretation. The putative X-ray source in N is found to be absorbed by NH = 1.4+0.7−0.4 × 1024 cm−2. The estimated 2−10 keV luminosity of the N source is 1.3 × 1043 erg s−1, about a factor of 2 larger than that of SW during the NuSTAR observation. Uncorrelated variability above and below 10 keV between the Suzaku and NuSTAR observations appears to support the double source interpretation. Variability in spectral hardness and Fe K line flux between the previous X-ray observations is also consistent with this picture.

scholarly journals 371 Half Value Layer and X-ray Spectra of CT : Comparison of Three CT-scanners

1997 ◽  
Vol 53 (8) ◽  
pp. 1243
Author(s):  
H Okamoto ◽  
T Kumatani ◽  
K Ueda ◽  
O Hiruma ◽  
Y Kumatani ◽  
...  
Keyword(s):  
X Ray ◽  
Ct Scanners

scholarly journals Evaluation and Comparison of Dose Profiles and Patient Doses among X-ray CT Scanners

2005 ◽  
Vol 61 (5) ◽  
pp. 683-690 ◽  
Author(s):  
KOSUKE MATSUBARA ◽  
KICHIRO KOSHIDA ◽  
MASAYUKI SUZUKI ◽  
ATSUSHI FUKUDA ◽  
CHIKAKO KAWABATA ◽  
...  
Keyword(s):  
X Ray ◽  
Patient Doses ◽  
Ct Scanners

Energy of microwave-emitting electrons and hard X-ray/microwave source model in solar flares

Solar Physics ◽  
1986 ◽  
Vol 105 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Nariaki Nitta ◽  
Takeo Kosugi
Keyword(s):  
Solar Flares ◽  
Source Model ◽  
Microwave Source ◽  
X Ray

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

2018 ◽  
Vol 91 (1081) ◽  
pp. 20170285 ◽  
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.

SU-E-I-85: Application of Real-Time Dosimetry to Characterize the X-Ray Penetrability of CT Scanners

2011 ◽  
Vol 38 (6Part5) ◽  
pp. 3415-3415
Author(s):  
S McKenney ◽  
G Burkett ◽  
D Gelskey ◽  
J Boone
Keyword(s):  
Real Time ◽  
X Ray ◽  
Ct Scanners

A dose reduction x-ray beam positioning system for high-speed multislice CT scanners

2000 ◽  
Vol 27 (12) ◽  
pp. 2659-2668 ◽  
Author(s):  
Thomas L. Toth ◽  
Neil B. Bromberg ◽  
Tin-Su Pan ◽  
Jerry Rabe ◽  
Steven J. Woloschek ◽  
...  
Keyword(s):  
Dose Reduction ◽  
High Speed ◽  
Multislice Ct ◽  
Positioning System ◽  
X Ray ◽  
Ct Scanners

scholarly journals A measurement-based X-ray source model characterization for CT dosimetry computations

2015 ◽  
Vol 16 (6) ◽  
pp. 386-400 ◽  
Author(s):  
Mitchell Sommerville ◽  
Yannick Poirier ◽  
Mauro Tambasco
Keyword(s):  
Source Model ◽  
X Ray ◽  
Ct Dosimetry
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