Four-dimensional cardiac reconstruction from rotational x-ray sequences: first results for 4D coronary angiography

2009 ◽  
Author(s):  
Eberhard Hansis ◽  
Hermann Schomberg ◽  
Klaus Erhard ◽  
Olaf Dössel ◽  
Michael Grass
Keyword(s):  
Coronary Angiography ◽  
X Ray ◽  
First Results ◽  
Cardiac Reconstruction ◽  
Ray Sequences

On tungstates of divalent cations (III) – Pb5O2[WO6]

2020 ◽  
Vol 235 (8-9) ◽  
pp. 311-317
Author(s):  
Stephan G. Jantz ◽  
Florian Pielnhofer ◽  
Henning A. Höppe
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Quantum Chemical ◽  
Density Functional ◽  
Divalent Cations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
First Results ◽  
Electrostatic Calculations

Abstract${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ was discovered as a frequently observed side phase during our investigation on lead tungstates. Its crystal structure was solved by single-crystal X-ray diffraction ($P{2}_{1}/n$, $a=7.4379\left(2\right)$ Å, $b=12.1115\left(4\right)$ Å, $c=10.6171\left(3\right)$ Å, $\beta =90.6847\left(8\right)$°, $Z=4$, ${R}_{\text{int}}=0.038$, ${R}_{1}=0.020$, $\omega {R}_{2}=0.029$, 4188 data, 128 param.) and is isotypic with ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{Te}}_{6}\right]$. ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ comprises a layered structure built up by non-condensed [WO6]${}^{6-}$ octahedra and ${\left[{\text{O}}_{4}{\text{Pb}}_{10}\right]}^{12+}$ oligomers. The compound was characterised by spectroscopic measurements (Infrared (IR), Raman and Ultraviolet–visible (UV/Vis) spectra) as well as quantum chemical and electrostatic calculations (density functional theory (DFT), MAPLE) yielding a band gap of 2.9 eV fitting well with the optical one of 2.8 eV. An estimation of the refractive index based on the Gladstone-Dale relationship yielded $n\approx 2.31$. Furthermore first results of the thermal analysis are presented.

Abstract 2805: Assessment of Coronary Artery Disease Using Magnetic Resonance Coronary Angiography: A Multicenter Trial

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shingo Kato ◽  
Hajime Sakuma ◽  
Nanaka Ishida ◽  
Masaki Ishida ◽  
Motonori Nagata ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Magnetic Resonance ◽  
Coronary Angiography ◽  
Multicenter Study ◽  
Sublingual Administration ◽  
X Ray ◽  
Coronary Mra ◽  
Artery Disease ◽  
Roc Area

Background: CT coronary angiography is widely used to assess the presence of significant coronary artery disease (CAD). However, CT approach is associated with low but nonnegligible cancer risk. The purpose of this prospective multicenter study was to evaluate the diagnostic performance of coronary magnetic resonance angiography (MRA) in the ability to identify patients with significant CAD compared with coronary angiography. Materials and Methods: The subjects were recruited from 7 institutions. Free breathing coronary MR angiograms covering the entire coronary artery tree were obtained in 138 patients who were suspicious of CAD. Non-contrast enhanced images were acquired with a commercial 1.5T MR imager and five-element cardiac coils after sublingual administration of isosorbide dinitrate. Conventional X-ray coronary angiography was performed within 4 weeks after coronary MRA. MR and X-ray angiograms were sent to a core laboratory for blinded interpretation. Coronary MR angiograms were evaluated by two experienced investigators by using sliding partial MIP reconstruction. Quantitative X-ray coronary angiography analysis was performed with significant CAD defined as luminal narrowing of at least 50% of the diameter. Results: The mean imaging time of coronary MRA was 9.5 ± 4.9 minutes. The prevalence of significant disease on X-ray angiography was 45% (62/138). On a vessel-based analysis, the area under receiver operating characteristic (ROC) curve for the MRA compared with X-ray angiography was 0.90 (95% CI; 0.86 to 0.93). On a patient based analysis, the ROC area was 0.88 (95% CI; 0.81– 0.93). The sensitivity, specificity, positive and negative predictive values of coronary MRA by vessel analysis were 78% (95% CI; 68 – 86%), 86% (82–90%), 60% (51– 69%), 94% (90–96%). These values by patient analysis were 87% (95% CI; 76–94%), 71% (59 – 81%), 71% (59 – 81%), 87% (76–94%). Conclusions: In the current multicenter study using commercial 1.5T MR imagers and sliding partial MIP reconstruction, the diagnostic accuracy of coronary MRA compared to quantitative coronary angiography is good, reflected by an ROC area of 0.88 on patient-based analysis. High negative predictive value indicates that coronary MRA can be used for screening CAD.

Abstract 2598: Radiation Exposure, Procedure Time And Contrast Load In Patients Referred For Coronary Angiography: Head-to-head Comparison Of Dual Source Ct With Conventional Coronary Angiography.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Carlos A Van Mieghem ◽  
Annick C Weustink ◽  
Marcel Kofflard ◽  
A. Schreve-Steensma ◽  
Niels A Matheijssen ◽  
...  
Keyword(s):  
Coronary Angiography ◽  
Radiation Exposure ◽  
Contrast Material ◽  
Conventional Coronary Angiography ◽  
Dual Source Ct ◽  
Procedure Time ◽  
X Ray ◽  
Iodinated Contrast ◽  
Dual Source ◽  
The Mean

Introduction and aim: Dual Source CT (DSCT) scanners, with an increased temporal resolution (83 ms), are becoming widely available. To evaluate the current potential of this scanner in the clinical arena, we performed a head-to-head comparison with conventional coronary angiography (CCA) taking into account the following parameters: radiation exposure, procedure time and contrast load. Methods: During a one-year period (april 2006 to march 2007) we compared a consecutive patient group who underwent DSCT (318 patients, 222 male, mean age 68±11 years) and CCA (352 patients, 258 male, mean age 61±12) respectively. Patients with previous bypass surgery were excluded. In DSCT, the volume of iodinated contrast material was adapted to the scan time. A contrast bolus was injected in an antecubital vein at a flow rate of 5.0 ml/s followed by a saline chaser of 40 ml at 5.0 ml/s. Each tube provided 412 mAs/rot (maximum), and full X-ray tube current was given during 25–70% of the RR-interval. Exposure data were collected using the x-ray dosimetrical reports from DSCT and CCA. Results: The mean procedure time using DSCT and CCA was 16.1±4.7 min and 44.1±25.5 min (p<0.001), respectively. The mean contrast load in DSCT and CCA was 77.9±7.6 ml and 175.3±4.3ml (p<0.001), respectively. The overall radiation exposure for DSCT and CCA was calculated as 15.3±4.0 mSv and 5.7±4.3 mSv, respectively. Radiation exposure with DSCT was significantly lower (p<0.001) in patients with a heart rate of >70 bpm (12.9±3.1 mSv ) as compared with patients with heart rates <70 bpm (16.4±3.8 mSv). Conclusion: In today’s practice currently available DSCT scanners perform favorably as compared with CCA, considering procedure time and patient contrast load. Radiation exposure with DSCT remains higher but should not be considered a major disadvantage taking into account the relatively old age group that generally undergoes coronary angiography and the major benefit of not being exposed to the risks of an invasive procedure.

X-Ray Coronary Angiography

2002 ◽  
pp. 602-635
Author(s):  
Stephan Windecker ◽  
Bernhard Meier
Keyword(s):  
Coronary Angiography ◽  
X Ray

The Prospects of Interventional Coronary Angiography with Thomson Laser-Electron X-ray Source

2018 ◽  
Author(s):  
I.A. Artyukov ◽  
E.G. Bessonov ◽  
N.V. Dyachkov ◽  
R.M. Feshchenko ◽  
M.V. Gorbunkov ◽  
...  
Keyword(s):  
Coronary Angiography ◽  
X Ray

DICHROISM IN ANGLE-RESOLVED PHOTOEMISSION FROM Pt(111)

2002 ◽  
Vol 09 (02) ◽  
pp. 883-888 ◽  
Author(s):  
G. H. FECHER ◽  
J. BRAUN ◽  
A. OELSNER ◽  
CH. OSTERTAG ◽  
G. SCHÖNHENSE
Keyword(s):  
Circular Dichroism ◽  
Band Structure ◽  
Valence Band ◽  
Single Step ◽  
Core Level ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Band Emission ◽  
First Results ◽  
Circular Dichroïsm

The angular dependence of the circular dichroism in photoemission from Pt(111) was investigated for excitation with VUV and soft X-ray radiation. VUV excitation was used to probe band structure and the circular dichroism for valence band emission. The measurements are compared to full relativistic single step photoemission calculations. XPS was used to investigate the circular dichroism in emission from the 4f core level. In this case, the dichroism is induced by photoelectron diffraction. First results from single step core level calculations are compared to the experimental observations.

scholarly journals The Case Study of the Medieval Town Walls of Gubbio in Italy: First Results on the Characterization of Mortars and Binders

Heritage ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 468-478 ◽  
Author(s):  
Fernanda Carvalho ◽  
Andreia Lopes ◽  
Antonella Curulli ◽  
Teresa da Silva ◽  
Maria Lima ◽  
...  
Keyword(s):  
Polarized Light ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heritage Sites ◽  
First Results ◽  
Restoration Practices ◽  
Climate Events

Good conservation and restoration practices of cultural heritage assets rely on the knowledge of original materials. In the framework of the HERACLES Project (HERACLES—HEritage Resilience Against CLimate Events on Site, H2020 Grant Agreement 700395), dealing with the effects of climatic actions and natural hazards on built heritage, a set of important heritage sites are currently under study to improve their resilience against climate events. Among these are the medieval Gubbio Town Walls in Italy. The present work focuses on the mortars and binders of this monument and collected samples related to different parts of the Walls, corresponding to various historical periods of construction and interventions. They were characterized to determine their minerochemical composition, thermal behavior, and morphology. For that purpose, ex-situ laboratory techniques, such as X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), polarized light microscopy (PLM), scanning electron microscopy (SEM), and simultaneous differential thermal analysis and thermogravimetry (TG-DTA) were used to discern trends in different sampling areas due to construction/reconstruction periods and building techniques.

On the X-Ray Source Luminosity Distributions in the Bulge and Disk of M31: First Results from the [ITAL]XMM-Newton[/ITAL] Survey

2002 ◽  
Vol 571 (1) ◽  
pp. L17-L21 ◽  
Author(s):  
Sergey P. Trudolyubov ◽  
Konstantin N. Borozdin ◽  
William C. Priedhorsky ◽  
Keith O. Mason ◽  
France A. Cordova
Keyword(s):  
X Ray ◽  
First Results
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