Efficient generation of super-Gaussian short-axis profiles in UV line-beam systems

2021 ◽  
Author(s):  
Henning Kalis ◽  
Florian Seck ◽  
Markus Wiesner ◽  
Mikhail Ivanenko ◽  
Vyacheslav Grimm ◽  
...  
Keyword(s):  
Short Axis ◽  
Efficient Generation ◽  
Line Beam

Advanced Lateral Crystal Growth of a-Si Thin Films by Double-Pulsed Irradiation of All Solid-State Lasers

2003 ◽  
Vol 762 ◽  
Author(s):  
Toshio Kudo ◽  
Koji Seike ◽  
Kazunori Yamazaki ◽  
Hirohito Komori ◽  
Sachi Yawaka ◽  
...  
Keyword(s):  
Thin Films ◽  
Crystal Growth ◽  
Solid State ◽  
Short Axis ◽  
Scanning Direction ◽  
Complete Melting ◽  
Melting Region ◽  
Scanning Step ◽  
Lateral Crystal ◽  
Line Beam

AbstractA compact annealing machine with all solid-state green lasers has been developed, which has the advantage of widely adjustable solidification rate through the delay time control of two long pulses (pulse width ~100ns). Advanced lateral crystal growth (ALCG) process has been proved by the double-pulsed all solid-state laser annealing. The laser beam has a line shape 0.1mm wide and 17mm long, and the beam profile on the short axis is quasi-Gaussian (FWHM 0.1mm). Scanning the line beam along the short axis at the 86% overlapping ratio, the lateral crystal growth area of width 14μm, parallel to the long axis, is sequentially formed at the pitch of 14μm towards the scanning direction. The advanced lateral growth mechanism is easily explained as follows: (1) At the first irradiation, twin seed lines of width 4μm, parallel to the long axis, generates at a boundary between a near-complete melting region and a complete melting region. (2) At the second irradiation of scanning step 14μm, the front seed line in the scanning direction grows symmetrically toward both sides. (3) At the third irradiation of scanning step 2x14μm, the seeds laterally grow until stopped by the growing of seeds on both sides. Finally the ALCG process by the scanning line-beam technique like the current ELA enables us to produce the laterally grown Si thin-films sequentially arranging the belt-shaped texture at the pitch of 14μm. The quality of the laterally grown Si films is quite well except for the projections generated by the bump of lateral growing seeds.

An approach for comparative quantification of myocardial blood flow (0-15-H2O-PET), perfusion (Tc-99m-tetrofosmin-SPECT), and metabolism (F 18-FDG-PET)

2001 ◽  
Vol 40 (05) ◽  
pp. 164-171 ◽  
Author(s):  
B. Nowak ◽  
H.-J. Kaiser ◽  
S. Block ◽  
K.-C. Koch ◽  
J. vom Dahl ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Fdg Pet ◽  
Model Fitting ◽  
Compartment Model ◽  
Left Ventricular ◽  
Short Axis ◽  
New Approach ◽  
Single Compartment Model ◽  
Tissue Fraction

Summary Aim: In the present study a new approach has been developed for comparative quantification of absolute myocardial blood flow (MBF), myocardial perfusion, and myocardial metabolism in short-axis slices. Methods: 42 patients with severe CAD, referred for myocardial viability diagnostics, were studied consecutively with 0-15-H2O PET (H2O-PET) (twice), Tc-99m-Tetrofosmin 5PECT (TT-SPECT) and F-18-FDG PET (FDG-PET). All dato sets were reconstructed using attenuation correction and reoriented into short axis slices. Each heart was divided into three representative slices (base, rnidventricular, apex) and 18 ROIs were defined on the FDG PET images and transferred to the corresponding H2O-PET and TT-SPECT slices. TT-SPECT and FDG-PET data were normalized to the ROI showing maximum perfusion. MBF was calculated for all left-ventricular ROIs using a single-compartment-model fitting the dynamic H2O-PET studies. Microsphere equivalent MBF (MBF_micr) was calculated by multiplying MBF and tissue-fraction, a parameter which was obtained by fitting the dynamic H2O-PET studies. To reduce influence of viability only well perfused areas (>70% TT-SPECT) were used for comparative quantification. Results: First and second mean global MBF values were 0.85 ml × min-1 × g-1 and 0.84 ml × min-1 × g1, respectively, with a repeatability coefficient of 0.30 ml ÷ min-1 × gl. After sectorization mean MBF_micr was between 0.58 ml × min1 ÷ ml"1 and 0.68 ml × min-1 × ml"1 in well perfused areas. Corresponding TT-SPECT values ranged from 83 % to 91 %, and FDG-PET values from 91 % to 103%. All procedures yielded higher values for the lateral than the septal regions. Conclusion: Comparative quantification of MBF, MBF_micr, TT-SPECT perfusion and FDG-PET metabolism can be done with the introduced method in short axis slices. The obtained values agree well with experimentally validated values of MBF and MBF_micr.

Segmentation of Short Axis CMR Images Using Hybrid Method

2018 ◽  
Vol 14 (3) ◽  
pp. 461-467
Author(s):  
A.V. Nageswararao ◽  
S. Peter Babu ◽  
S. Srinivasan
Keyword(s):  
Hybrid Method ◽  
Short Axis

Distribution and Characteristics of Intrathoracic Lymphadenopathy in TB/HIV Co-Infection

2019 ◽  
Vol 19 (4) ◽  
pp. 414-420
Author(s):  
Payam Mehrian ◽  
Abtin Doroudinia ◽  
Moghadaseh Shams ◽  
Niloufar Alizadeh
Keyword(s):  
Lymph Nodes ◽  
Cross Sectional Study ◽  
Short Axis ◽  
Mediastinal Lymph Nodes ◽  
Sectional Study ◽  
Cross Sectional ◽  
Immunodeficiency Virus ◽  
Hilar Adenopathy ◽  
The Right ◽  
Pulmonary Abnormalities

Background: Intrathoracic Lymphadenopathy (ITLN) in Human Immunodeficiency Virus (HIV) infected patients may have various etiologies and prognoses. Etiologies of ITLN can be distinguished based on the distribution of enlarged lymph nodes. Sometimes tuberculosis (TB) is the first sign of underlying HIV infection. Objective: We sought to determine ITLN distribution and associated pulmonary findings in TB/HIV co-infection using Computed Tomography (CT) scan. Methods: In this retrospective, observational, cross-sectional study, chest CT scans of 52 patients with TB/HIV co-infection were assessed for enlarged intrathoracic lymph nodes (>10 mm in short axis diameter), lymphadenopathy (LAP) distribution, calcification, conglomeration, the presence of hypodense center and associated pulmonary abnormalities. LAP distribution was compared in TB/HIV co-infection with isolated TB infection. Results: Mediastinal and/or hilar LAP were seen in 53.8% of TB/HIV co-infection patients. In all cases, LAP was multinational. The most frequent stations were right lower paratracheal and subcarinal stations. Lymph node conglomeration, hypodense center and calcification were noted in 25%, 21.4% and 3.5% of patients, respectively. LAP distribution was the same as that in patients with isolated TB infection except for the right hilar, right upper paratracheal and prevascular stations. All patients with mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Conclusion: All patients with TB/HIV co-infection and mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Superior mediastinal lymph nodes were less commonly affected in TB/HIV co-infection than isolated TB.

Sign in / Sign up

Export Citation Format

Share Document