An evaluation of organ dose modulation on a GE optima CT660‐computed tomography scanner
29
Citation
16
Reference
10
Related Paper
Citation Trend
Abstract:
Organ Dose Modulation or ODM (GE Healthcare, Milwaukee, WI) was evaluated to characterize changes in , image noise, effective dose, and organ dose saving to patients. Three separate investigations were completed: a tube current modulation phantom was scanned with and without ODM, a phantom was scanned with ODM, and Monte Carlo simulations were performed. ODM was found to reduce the by approximately 20% whilst increasing the noise by approximately 14%. This was reflected in the dose distribution, where the anterior peripheral dose was reduced by approximately 40% whilst the identical posterior dose remained largely unaffected. Enabling ODM for the entire scan would reduce the effective dose by approximately 24%; however, this saving reduces to 5% if the images are matched for . These savings mostly originated from reductions in dose to the stomach, breasts, colon, bladder, and liver. ODM has the effect of a global reduction in with an associated increase in image noise. The benefit of ODM was found to be reduced when the dose‐saving contribution from the reduced was removed. Given that there is a higher contribution to effective dose throughout the body from the anterior projections, consideration should be given to applying ODM throughout. PACS number(s): 87.10.Rt, 87.53.Bn, 87.57.C‐, 87.57.Q‐Bio-chip scanner is the key component for the application of bio-chip.Laser scanner and CCD scanner are introduced in this paper,and4kinds of bio-chip scanner are listed.The develop ment trend of bio-chip scanner is dis cussed also.
Laser Scanning
Cite
Citations (0)
Cite
Citations (69)
The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. Electronic and mechanical design of the scanner to make it a self standing sensor was completed during the last six months of the project. The prototype scanner was tested with methane leaks at 15 feet and 30 feet, at a flow rate of 25 SCFH. The prototype scanner successfully detected the leaks. This concluded the project.
Cite
Citations (0)
The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at En'Urga Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. Electronic design of the scanner to make it a self standing sensor is currently in progress. During the last six months of the project, the electronic and mechanical design will be completed and evaluated at En'Urga Inc.
Cite
Citations (0)
Now we are living in digital era. Every aspect of life is becoming digital. It is true for reading books, papers, or journals also. However, our old books or journals are in analog format. To convert those papers, books, or journals in digital format, we need a scanner. Accordingly, if the scanner feed pages automatically, it will be more easier. However, in present market, auto feeding scanner is a very much costly device. In this paper, we propose a new method to build a low cost automatic document feeding scanner. We also compare the performance of our proposed scanner with other scanners available in market and found that our scanners output is similar to them. This discussion also provides a comparison table of different types of Auto Feeding Scanner.
Table (database)
Cite
Citations (1)
The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using the scanner to determine natural gas pipeline leaks. Further field evaluations and optimization of the scanner are required before commercialization of the scanner can be initiated.
Cite
Citations (0)
Cost of ownership of scanners for the manufacturing of front end layers is becoming increasingly expensive. The ability to quickly switch the production of a layer to another scanner in case it is down is important. This paper presents a method to match the scanner grids in the most optimal manner so that use of front end scanners in effect becomes interchangeable. A breakdown of the various components of overlay is given and we discuss methods to optimize the matching strategy in the fab. A concern here is how to separate the scanner and process induced effects. We look at the relative contributions of intrafield and interfield errors caused by the scanner and the process. Experimental results of a method to control the scanner grid are presented and discussed. We compare the overlay results before and after optimizing the scanner grids and show that the matching penalty is reduced by 20%. We conclude with some thoughts on the need to correct the remaining matching errors.
Cite
Citations (1)
For the high volume manufacturing at the 45nm node and beyond it is crucial to match the OPC behaviour of all scanners used at a given process step. For this task the ASML LithoTuner PatternMatcher software was used. LithoTuner PatternMatcher is a tool to improve the proximity differences between a reference scanner and one or more so called 'to be matched' scanners. The optimization uses the concept of sensitivities of CDs of critical features towards adjustable scanner parameters in combination with the delta CD's of those critical features. To perform the scanner matching it is very important to have accurate and repeatable CD data. Therefore we investigated the use of scatterometry as a replacement for the traditional CDSEM measurement. Scatterometry significantly enhances the measurement precision while simultaneously reduces the measurement time. In a first step we determined the sensitivities of the structures by measuring the CD response to small perturbations of the individual scanner parameter settings. CD through pitch and repeating 2 dimensional line end structures were measured using the ASML YieldStar tool and a Hitachi CDSEM. The scatterometry- and CDSEM based sensitivities of the scanner parameter settings are compared. Finally a scanner matching based on both sets of sensitivities has been performed. In this article we will show that both methods are suited to perform the scanner matching. We will also present the differences between the two sets of sensitivities obtained with scatterometry and CDSEM. At the end we will present the results of the tool matching and show the results of a cross check. In the cross check sensitivities obtained with the use of scatterometry were used for the scanner matching next to SEM metrology used for verification.
Cite
Citations (0)
The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at En'Urga Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, a rugged prototype scanner will be developed and evaluated, both at En'Urga Inc. and any potential field sites.
Cite
Citations (0)
The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at En'Ungra Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner.
Cite
Citations (0)