Nanotopography induced contact guidance of the F11 cell line during neuronal differentiation: a neuronal model cell line for tissue scaffold development

International Nuclear Information System (INIS)

Wieringa, Paul; Micera, Silvestro; Tonazzini, Ilaria; Cecchini, Marco

2012-01-01

The F11 hybridoma, a dorsal root ganglion-derived cell line, was used to investigate the response of nociceptive sensory neurons to nanotopographical guidance cues. This established this cell line as a model of peripheral sensory neuron growth for tissue scaffold design. Cells were seeded on substrates of cyclic olefin copolymer (COC) films imprinted via nanoimprint lithography (NIL) with a grating pattern of nano-scale grooves and ridges. Different ridge widths were employed to alter the focal adhesion formation, thereby changing the cell/substrate interaction. Differentiation was stimulated with forskolin in culture medium consisting of either 1 or 10% fetal bovine serum (FBS). Per medium condition, similar neurite alignment was achieved over the four day period, with the 1% serum condition exhibiting longer, more aligned neurites. Immunostaining for focal adhesions found the 1% FBS condition to also have fewer, less developed focal adhesions. The robust response of the F11 to guidance cues further builds on the utility of this cell line as a sensory neuron model, representing a useful tool to explore the design of regenerative guidance tissue scaffolds. (paper)

The use of image-guidance during transsphenoidal pituitary surgery in the United States

Science.gov (United States)

Chung, Thomas K.; Riley, Kristen O.

2015-01-01

Background: Intraoperative image guidance is a useful modality for transsphenoidal pituitary surgery. However, the outcomes associated with this technology have not been systematically evaluated. Objective: The purpose of the study was to quantify complication rates with and without the use of image guidance during transsphenoidal pituitary surgery using a nationwide database with broadly applicable results. Methods: A retrospective analysis of the Nationwide Inpatient Sample was performed from 2007 to 2011. Transsphenoidal pituitary resections for adenomas were identified by International Classification of Diseases-9th Revision, Clinical Modification code. The effect of image guidance on cerebrospinal fluid (CSF) leak complications and cost-benefit was analyzed. Results: A total of 48,848 transsphenoidal pituitary resections were identified, of which 77.5% were partial resections and 22.5% were complete. Pathologic indications included benign (89.3%), malignant primary (0.6%), and malignant secondary (0.4%). Complications included same-stay death (0.4%), CSF leak (8.8%), postoperative CSF rhinorrhea (1.9%), diabetes insipidus (12.4%), and meningitis (0.4%). Image guidance was employed in 7% (n = 3401) of all cases. When analyzed by modality, computed tomography (CT)-assisted procedures had lower CSF rhinorrhea rates (1.1%) compared with cases with no image guidance (1.9%), whereas magnetic resonance (MR)-assisted procedures had the highest rates (2.7%, χ2 p surgery had significantly shorter length of stay (2.9 days) versus no image guidance (3.7 days, p surgery is associated with a lower rate of CSF leak, shorter length of stay, and lower cost compared with patients without image guidance. Further studies that control for severity and extent of disease are warranted to confirm this finding. PMID:25975254

Evaluation of Image-Guidance Strategies in the Treatment of Localized Prostate Cancer

International Nuclear Information System (INIS)

Kupelian, Patrick A.; Lee, Choonik; Langen, Katja M.; Zeidan, Omar A.; Manon, Rafael R.; Willoughby, Twyla R.; Meeks, Sanford L.

2008-01-01

Purpose: To compare different image-guidance strategies in the alignment of prostate cancer patients. Using data from patients treated using daily image guidance, the remaining setup errors for several different strategies were retrospectively calculated. Methods and Materials: The alignment data from 74 patients treated with helical tomotherapy were analyzed, resulting in a data set of 2,252 fractions during which a megavoltage computed tomography image was used for image guidance with intraprostatic metallic fiducials. Given the daily positional adjustments, a variety of protocols, differing in imaging frequency and method, were retrospectively studied. The residual setup errors were determined for each protocol. Results: As expected, the systematic errors were effectively reduced with imaging. However, the random errors were unaffected. Even when image guidance was performed every other day with a running mean of the previous displacements, residual setup errors >5 mm occurred in 24% of all fractions. This frequency increased to about 40% if setup errors >3 mm were scored. Conclusion: Setup errors increased with decreasing frequency of image guidance. However, residual errors were still significant at the 5-mm level, even with imaging was performed every other day. This suggests that localizations must be performed daily in the set up of prostate cancer patients during a course of external beam radiotherapy

Added Value of Contrast-Enhanced Ultrasound on Biopsies of Focal Hepatic Lesions Invisible on Fusion Imaging Guidance.

Science.gov (United States)

Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun

2017-01-01

To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5-1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making.

An image overall complexity evaluation method based on LSD line detection

Science.gov (United States)

Li, Jianan; Duan, Jin; Yang, Xu; Xiao, Bo

2017-04-01

In the artificial world, whether it is the city's traffic roads or engineering buildings contain a lot of linear features. Therefore, the research on the image complexity of linear information has become an important research direction in digital image processing field. This paper, by detecting the straight line information in the image and using the straight line as the parameter index, establishing the quantitative and accurate mathematics relationship. In this paper, we use LSD line detection algorithm which has good straight-line detection effect to detect the straight line, and divide the detected line by the expert consultation strategy. Then we use the neural network to carry on the weight training and get the weight coefficient of the index. The image complexity is calculated by the complexity calculation model. The experimental results show that the proposed method is effective. The number of straight lines in the image, the degree of dispersion, uniformity and so on will affect the complexity of the image.

On line portal imaging

International Nuclear Information System (INIS)

Munro, Peter

1995-01-01

Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

Advances in imaging for oncology guidance

International Nuclear Information System (INIS)

Amies, Christopher J.

2008-01-01

Over the last 30 years major improvements in medical imaging have played a significant role to help advance the management of oncology diseases. These advances have covered the continuum of care from screening, diagnosis, staging, treatment planning and intervention. More recently image guided radiation therapy (IGRT) has placed sophisticated imaging closer to the treatment event. The opportunity to improve care seems obvious; however the clinical benefits of IGRT are at present not easily proven and yet contribute to the complexity of treatment and the rising costs of care. It is proposed that this is in part due to the present immaturity of IGRT technology development, which is predominantly determined by the challenge of achieving precise delivery of radiation in one or many episodes (fractions) for very different diseases. There is no single type or mode of imaging that will be suitable to address all radiotherapy guidance challenges whether defined by the general criteria identified for a specific disease or the unique characteristics encountered with an individual patient. Finally the wide adoption of this or any medical technology general requires the attainment of a sufficient degree of safety and efficiency. I present the challenges faced by industry as well as select interesting technology based solutions and concepts that may help advance the field of oncology guidance

Gynecologic radiation therapy. Novel approaches to image-guidance and management

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, Akila N. [Harvard Medical School, Boston, MA (United States). Dept. of Radiation Oncology; Kirisits, Christian; Poetter, Richard (eds.) [Vienna General Hospital Medical Univ. (Austria). Dept. of Radiotherapy; Erickson, Beth E. [Medical College of Wisconsin Clinics Froedtert Hospital, Milwaukee, WI (United States). Dept. of Radiation Oncology

2011-07-01

Recent advances in the treatment of gynecologic malignancies led to a new worldwide consensus to introduce image guidance to gynecologic radiation therapy, particularly to brachytherapy. The book summarizes the changed practice of management: treatment planning for cervical cancer, not modified for over 60 years, has been shifted to an image-based approach, endometrial cancer management with an increase in the use of chemotherapy and vaginal brachytherapy, and vaginal cancer therapy including image guidance and high-dose delivery with IMRT. (orig.)

Three-dimensional Image Fusion Guidance for Transjugular Intrahepatic Portosystemic Shunt Placement.

Science.gov (United States)

Tacher, Vania; Petit, Arthur; Derbel, Haytham; Novelli, Luigi; Vitellius, Manuel; Ridouani, Fourat; Luciani, Alain; Rahmouni, Alain; Duvoux, Christophe; Salloum, Chady; Chiaradia, Mélanie; Kobeiter, Hicham

2017-11-01

To assess the safety, feasibility and effectiveness of image fusion guidance with pre-procedural portal phase computed tomography with intraprocedural fluoroscopy for transjugular intrahepatic portosystemic shunt (TIPS) placement. All consecutive cirrhotic patients presenting at our interventional unit for TIPS creation from January 2015 to January 2016 were prospectively enrolled. Procedures were performed under general anesthesia in an interventional suite equipped with flat panel detector, cone-beam computed tomography (CBCT) and image fusion technique. All TIPSs were placed under image fusion guidance. After hepatic vein catheterization, an unenhanced CBCT acquisition was performed and co-registered with the pre-procedural portal phase CT images. A virtual path between hepatic vein and portal branch was made using the virtual needle path trajectory software. Subsequently, the 3D virtual path was overlaid on 2D fluoroscopy for guidance during portal branch cannulation. Safety, feasibility, effectiveness and per-procedural data were evaluated. Sixteen patients (12 males; median age 56 years) were included. Procedures were technically feasible in 15 of the 16 patients (94%). One procedure was aborted due to hepatic vein catheterization failure related to severe liver distortion. No periprocedural complications occurred within 48 h of the procedure. The median dose-area product was 91 Gy cm 2 , fluoroscopy time 15 min, procedure time 40 min and contrast media consumption 65 mL. Clinical benefit of the TIPS placement was observed in nine patients (56%). This study suggests that 3D image fusion guidance for TIPS is feasible, safe and effective. By identifying virtual needle path, CBCT enables real-time multiplanar guidance and may facilitate TIPS placement.

Added value of contrast-enhanced ultrasound on biopsies of focal hepatic lesions invisible on fusion imaging guidance

Energy Technology Data Exchange (ETDEWEB)

Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2017-01-15

To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5–1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p < 0.001). The technical success rate of biopsy was 87.6% (14/16). After biopsy, there were changes in clinical decision making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making.

Added value of contrast-enhanced ultrasound on biopsies of focal hepatic lesions invisible on fusion imaging guidance

International Nuclear Information System (INIS)

Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun

2017-01-01

To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5–1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p < 0.001). The technical success rate of biopsy was 87.6% (14/16). After biopsy, there were changes in clinical decision making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making

TU-A-201-00: Image Guidance Technologies and Management Strategies

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

Recent years have seen a widespread proliferation of available in-room image guidance systems for radiation therapy target localization with many centers having multiple in-room options. In this session, available imaging systems for in-room IGRT will be reviewed highlighting the main differences in workflow efficiency, targeting accuracy and image quality as it relates to target visualization. Decision-making strategies for integrating these tools into clinical image guidance protocols that are tailored to specific disease sites like H&N, lung, pelvis, and spine SBRT will be discussed. Learning Objectives: Major system characteristics of a wide range of available in-room imaging systems for IGRT. Advantages / disadvantages of different systems for site-specific IGRT considerations. Concepts of targeting accuracy and time efficiency in designing clinical imaging protocols.

EPA guidance on improving the image of psychiatry.

Science.gov (United States)

Möller-Leimkühler, A M; Möller, H-J; Maier, W; Gaebel, W; Falkai, P

2016-03-01

This paper explores causes, explanations and consequences of the negative image of psychiatry and develops recommendations for improvement. It is primarily based on a WPA guidance paper on how to combat the stigmatization of psychiatry and psychiatrists and a Medline search on related publications since 2010. Furthermore, focussing on potential causes and explanations, the authors performed a selective literature search regarding additional image-related issues such as mental health literacy and diagnostic and treatment issues. Underestimation of psychiatry results from both unjustified prejudices of the general public, mass media and healthcare professionals and psychiatry's own unfavourable coping with external and internal concerns. Issues related to unjustified devaluation of psychiatry include overestimation of coercion, associative stigma, lack of public knowledge, need to simplify complex mental issues, problem of the continuum between normality and psychopathology, competition with medical and non-medical disciplines and psychopharmacological treatment. Issues related to psychiatry's own contribution to being underestimated include lack of a clear professional identity, lack of biomarkers supporting clinical diagnoses, limited consensus about best treatment options, lack of collaboration with other medical disciplines and low recruitment rates among medical students. Recommendations are proposed for creating and representing a positive self-concept with different components. The negative image of psychiatry is not only due to unfavourable communication with the media, but is basically a problem of self-conceptualization. Much can be improved. However, psychiatry will remain a profession with an exceptional position among the medical disciplines, which should be seen as its specific strength.

On image tube spectrophotometry of weak emission lines

International Nuclear Information System (INIS)

Duflot, R.

1979-01-01

The usual precision of image tube spectrophotometry measures relative to low intensity lines can be improved by the 'method of two lines'. This operating process tested on H II galactic regions leads to a precision of 13%. (Auth.)

Volumetric image-guidance: Does routine usage prompt adaptive re-planning? An institutional review

International Nuclear Information System (INIS)

Tanyi, James A.; Fuss, Martin H.

2008-01-01

Purpose. To investigate how the use of volumetric image-guidance using an on-board cone-beam computed tomography (CBCT) system impacts on the frequency of adaptive re-planning. Material and methods. Treatment courses of 146 patients who have undergone a course of external beam radiation therapy (EBRT) using volumetric CBCT image-guidance were analyzed. Target locations included the brain, head and neck, chest, abdomen, as well as prostate and non-prostate pelvis. The majority of patients (57.5%) were treated with hypo-fractionated treatment regimens (three to 15 fraction courses). The frequency of image-guidance ranged from daily (87.7%) to weekly or twice weekly. The underlying medical necessity for adaptive re-planning as well as frequency and consequences of plan adaptation to dose-volume parameters was assessed. Results. Radiation plans of 34 patients (23.3%) were adapted at least once (up to six time) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were: tumor change (mostly shrinkage: 10 patients; four patients more than one re-plan), change in abdominal girth (systematic change in hollow organ filling; n=7, two patients more than one re-plan), weight loss (n=5), and systematic target setup deviation from simulation (n=5). Adaptive re-plan was required mostly for conventionally fractionated courses; only 5 patient plans undergoing hypo-fractionated treatment were adjusted. In over 91% of adapted plans, the dose-volume parameters did deviate from the prescribed plan parameters by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume. Discussion. Routine use of volumetric image-guidance has in our practice increased the demand for adaptive re-planning. Volumetric CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment. In the vast majority of cases evaluated, the initial and adapted dose

Midcourse Guidance Law Based on High Target Acquisition Probability Considering Angular Constraint and Line-of-Sight Angle Rate Control

Directory of Open Access Journals (Sweden)

Xiao Liu

2016-01-01

Full Text Available Random disturbance factors would lead to the variation of target acquisition point during the long distance flight. To acquire a high target acquisition probability and improve the impact precision, missiles should be guided to an appropriate target acquisition position with certain attitude angles and line-of-sight (LOS angle rate. This paper has presented a new midcourse guidance law considering the influences of random disturbances, detection distance restraint, and target acquisition probability with Monte Carlo simulation. Detailed analyses of the impact points on the ground and the random distribution of the target acquisition position in the 3D space are given to get the appropriate attitude angles and the end position for the midcourse guidance. Then, a new formulation biased proportional navigation (BPN guidance law with angular constraint and LOS angle rate control has been derived to ensure the tracking ability when attacking the maneuvering target. Numerical simulations demonstrates that, compared with the proportional navigation guidance (PNG law and the near-optimal spatial midcourse guidance (NSMG law, BPN guidance law demonstrates satisfactory performances and can meet both the midcourse terminal angular constraint and the LOS angle rate requirement.

A Novel Guidance Law with Line-of-Sight Acceleration Feedback for Missiles against Maneuvering Targets

Directory of Open Access Journals (Sweden)

Kemao Ma

2014-01-01

Full Text Available Terminal guidance law design and its implementation are considered for homing missiles against maneuvering targets. The lateral acceleration dynamics are taken into account in the design. In the guidance law design, the line-of-sight acceleration signals are incorporated into the acceleration reference signals to compensate for the targets’ maneuvers. Then the commanded accelerations are designed and the convergent tracking of the lateral accelerations to these signals is proven theoretically. In the guidance implementation, a linear high-gain differentiator is used to estimate the line-of-sight rates and the line-of-sight acceleration signals. To avoid the magnifying effects of higher order differentiation, a practical design of commanded accelerations is given to realize approximate tracking of the lateral accelerations to the given reference signals. Simulation is conducted for both cases with and without measurement noises. The simulation results justify the feasibility of the design and the implementation.

Active instrumental guidance in interventional magnetic resonance imaging

International Nuclear Information System (INIS)

Wildermuth, S.; Erhart, P.; Leung, D.A.; Goehde, S.; Schoenenberger, A.; Debatin, J.F.

1998-01-01

Purpose: An active MR-based guidance system for visualisation of invasive instruments is described. Methods: The principle of MR tracking is based on the integration of a miniaturised coil into the tip of the instrument itself. A phantom experiment was designed to demonstrate the localising accuracy of this technique. In [dition, bicompatibility and warming effects were evaluated. Preliminary intravascular applications that were performed in animal experiments under MR guidance included embolisation, vascular occlusion as well as transjugular intrahepatic punctures. Percutaneous biopsies, cholecystostomies and laparoscopic applications were also evaluated with MR tracking. Results: Phantom experiments confirmed an excellent localisation accuracy of MR tracking compared to conventional r[iography. At a field strength of 0.5 T, the temperature increase remained below 2 C. Results of phantom experiments revealed a potential of significant heating dependent on the sequence parameters employed. MR tracking allowed a robust, simultaneously biplanar visualisation of the instrument tips in real time. Based on MR 'ro[ map' images, various intravascular and percutaneous interventions were successfully performed in vivo under MR guidance. Conclusions: MR tracking is a flexible concept permitting monitoring in the guidance of instruments in an MR environment. Various preliminary in vitro and in vivo experiments demonstrate safety, localisation accuracy and feasibility of this biplanar localisation technique in real time. (orig.) [de

Evaluation of a mobile augmented reality application for image guidance of neurosurgical interventions.

Science.gov (United States)

Kramers, Matthew; Armstrong, Ryan; Bakhshmand, Saeed M; Fenster, Aaron; de Ribaupierre, Sandrine; Eagleson, Roy

2014-01-01

Image guidance can provide surgeons with valuable contextual information during a medical intervention. Often, image guidance systems require considerable infrastructure, setup-time, and operator experience to be utilized. Certain procedures performed at bedside are susceptible to navigational errors that can lead to complications. We present an application for mobile devices that can provide image guidance using augmented reality to assist in performing neurosurgical tasks. A methodology is outlined that evaluates this mode of visualization from the standpoint of perceptual localization, depth estimation, and pointing performance, in scenarios derived from a neurosurgical targeting task. By measuring user variability and speed we can report objective metrics of performance for our augmented reality guidance system.

Echocardiographic and Fluoroscopic Fusion Imaging for Procedural Guidance: An Overview and Early Clinical Experience.

Science.gov (United States)

Thaden, Jeremy J; Sanon, Saurabh; Geske, Jeffrey B; Eleid, Mackram F; Nijhof, Niels; Malouf, Joseph F; Rihal, Charanjit S; Bruce, Charles J

2016-06-01

There has been significant growth in the volume and complexity of percutaneous structural heart procedures in the past decade. Increasing procedural complexity and accompanying reliance on multimodality imaging have fueled the development of fusion imaging to facilitate procedural guidance. The first clinically available system capable of echocardiographic and fluoroscopic fusion for real-time guidance of structural heart procedures was approved by the US Food and Drug Administration in 2012. Echocardiographic-fluoroscopic fusion imaging combines the precise catheter and device visualization of fluoroscopy with the soft tissue anatomy and color flow Doppler information afforded by echocardiography in a single image. This allows the interventionalist to perform precise catheter manipulations under fluoroscopy guidance while visualizing critical tissue anatomy provided by echocardiography. However, there are few data available addressing this technology's strengths and limitations in routine clinical practice. The authors provide a critical review of currently available echocardiographic-fluoroscopic fusion imaging for guidance of structural heart interventions to highlight its strengths, limitations, and potential clinical applications and to guide further research into value of this emerging technology. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Current Brachytherapy Quality Assurance Guidance: Does It Meet the Challenges of Emerging Image-Guided Technologies?

International Nuclear Information System (INIS)

Williamson, Jeffrey F.

2008-01-01

In the past decade, brachytherapy has shifted from the traditional surgical paradigm to more modern three-dimensional image-based planning and delivery approaches. The role of intraoperative and multimodality image-based planning is growing. Published American Association of Physicists in Medicine, American College of Radiology, European Society for Therapeutic Radiology and Oncology, and International Atomic Energy Agency quality assurance (QA) guidelines largely emphasize the QA of planning and delivery devices rather than processes. These protocols have been designed to verify compliance with major performance specifications and are not risk based. With some exceptions, complete and clinically practical guidance exists for sources, QA instrumentation, non-image-based planning systems, applicators, remote afterloading systems, dosimetry, and calibration. Updated guidance is needed for intraoperative imaging systems and image-based planning systems. For non-image-based brachytherapy, the American Association of Physicists in Medicine Task Group reports 56 and 59 provide reasonable guidance on procedure-specific process flow and QA. However, improved guidance is needed even for established procedures such as ultrasound-guided prostate implants. Adaptive replanning in brachytherapy faces unsolved problems similar to that of image-guided adaptive external beam radiotherapy

A hybrid optical system for broadband imaging in guidance and control

Science.gov (United States)

Wu, Xiaofang; Jiang, Yuesong; Shen, Chunyan; Zhao, Yiming

2006-11-01

A binary optics method has been adopted to improve upon a conventional optical system in guidance and control, and a hybrid broadband imaging system that includes a binary surface is analyzed and evaluated by optical design software ZEMAX. The practical design shows that the introduction of binary optics can simplify the structure of the imaging system and reduce the size and weight of the broadband guidance and control system. Moreover, it can help to acquire images of radiation of different wavelengths from targets; hence it will result in improved overall performance of missiles in wars.

Image guidance in trans-sphenoidal surgery for giant pituitary adenomas: Luxury or necessity?

OpenAIRE

Deepak Agrawal

2012-01-01

Background: In spite of availability of image guidance (neuronavigation) at major centers around the world, most trans-sphenoidal surgeries for pituitary adenomas continue to be done under fluoroscopic control. On the other hand, the high mortality and morbidity for giant pituitary adenomas is mainly due to inadequate tumor removal. Aims and Objectives: The objective of this study was to study to utility of image guidance in trans-sphenoidal surgeries for optimizing tumor removal in giant pit...

Image Mosaic Method Based on SIFT Features of Line Segment

Directory of Open Access Journals (Sweden)

Jun Zhu

2014-01-01

Full Text Available This paper proposes a novel image mosaic method based on SIFT (Scale Invariant Feature Transform feature of line segment, aiming to resolve incident scaling, rotation, changes in lighting condition, and so on between two images in the panoramic image mosaic process. This method firstly uses Harris corner detection operator to detect key points. Secondly, it constructs directed line segments, describes them with SIFT feature, and matches those directed segments to acquire rough point matching. Finally, Ransac method is used to eliminate wrong pairs in order to accomplish image mosaic. The results from experiment based on four pairs of images show that our method has strong robustness for resolution, lighting, rotation, and scaling.

Image-guidance for surgical procedures

International Nuclear Information System (INIS)

Peters, Terry M

2006-01-01

Contemporary imaging modalities can now provide the surgeon with high quality three- and four-dimensional images depicting not only normal anatomy and pathology, but also vascularity and function. A key component of image-guided surgery (IGS) is the ability to register multi-modal pre-operative images to each other and to the patient. The other important component of IGS is the ability to track instruments in real time during the procedure and to display them as part of a realistic model of the operative volume. Stereoscopic, virtual- and augmented-reality techniques have been implemented to enhance the visualization and guidance process. For the most part, IGS relies on the assumption that the pre-operatively acquired images used to guide the surgery accurately represent the morphology of the tissue during the procedure. This assumption may not necessarily be valid, and so intra-operative real-time imaging using interventional MRI, ultrasound, video and electrophysiological recordings are often employed to ameliorate this situation. Although IGS is now in extensive routine clinical use in neurosurgery and is gaining ground in other surgical disciplines, there remain many drawbacks that must be overcome before it can be employed in more general minimally-invasive procedures. This review overviews the roots of IGS in neurosurgery, provides examples of its use outside the brain, discusses the infrastructure required for successful implementation of IGS approaches and outlines the challenges that must be overcome for IGS to advance further. (topical review)

Mobile C-arm cone-beam CT for guidance of spine surgery: Image quality, radiation dose, and integration with interventional guidance

Energy Technology Data Exchange (ETDEWEB)

Schafer, S.; Nithiananthan, S.; Mirota, D. J.; Uneri, A.; Stayman, J. W.; Zbijewski, W.; Schmidgunst, C.; Kleinszig, G.; Khanna, A. J.; Siewerdsen, J. H. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21202 (United States); Department of Computer Science, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21202 (United States); Siemens Healthcare XP Division, Erlangen (Germany); Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, Maryland 21239 (United States); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21202 and Department of Computer Science, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2011-08-15

Purpose: A flat-panel detector based mobile isocentric C-arm for cone-beam CT (CBCT) has been developed to allow intraoperative 3D imaging with sub-millimeter spatial resolution and soft-tissue visibility. Image quality and radiation dose were evaluated in spinal surgery, commonly relying on lower-performance image intensifier based mobile C-arms. Scan protocols were developed for task-specific imaging at minimum dose, in-room exposure was evaluated, and integration of the imaging system with a surgical guidance system was demonstrated in preclinical studies of minimally invasive spine surgery. Methods: Radiation dose was assessed as a function of kilovolt (peak) (80-120 kVp) and milliampere second using thoracic and lumbar spine dosimetry phantoms. In-room radiation exposure was measured throughout the operating room for various CBCT scan protocols. Image quality was assessed using tissue-equivalent inserts in chest and abdomen phantoms to evaluate bone and soft-tissue contrast-to-noise ratio as a function of dose, and task-specific protocols (i.e., visualization of bone or soft-tissues) were defined. Results were applied in preclinical studies using a cadaveric torso simulating minimally invasive, transpedicular surgery. Results: Task-specific CBCT protocols identified include: thoracic bone visualization (100 kVp; 60 mAs; 1.8 mGy); lumbar bone visualization (100 kVp; 130 mAs; 3.2 mGy); thoracic soft-tissue visualization (100 kVp; 230 mAs; 4.3 mGy); and lumbar soft-tissue visualization (120 kVp; 460 mAs; 10.6 mGy) - each at (0.3 x 0.3 x 0.9 mm{sup 3}) voxel size. Alternative lower-dose, lower-resolution soft-tissue visualization protocols were identified (100 kVp; 230 mAs; 5.1 mGy) for the lumbar region at (0.3 x 0.3 x 1.5 mm{sup 3}) voxel size. Half-scan orbit of the C-arm (x-ray tube traversing under the table) was dosimetrically advantageous (prepatient attenuation) with a nonuniform dose distribution ({approx}2 x higher at the entrance side than at isocenter

Cone beam computed tomography image guidance system for a dedicated intracranial radiosurgery treatment unit.

Science.gov (United States)

Ruschin, Mark; Komljenovic, Philip T; Ansell, Steve; Ménard, Cynthia; Bootsma, Gregory; Cho, Young-Bin; Chung, Caroline; Jaffray, David

2013-01-01

Image guidance has improved the precision of fractionated radiation treatment delivery on linear accelerators. Precise radiation delivery is particularly critical when high doses are delivered to complex shapes with steep dose gradients near critical structures, as is the case for intracranial radiosurgery. To reduce potential geometric uncertainties, a cone beam computed tomography (CT) image guidance system was developed in-house to generate high-resolution images of the head at the time of treatment, using a dedicated radiosurgery unit. The performance and initial clinical use of this imaging system are described. A kilovoltage cone beam CT system was integrated with a Leksell Gamma Knife Perfexion radiosurgery unit. The X-ray tube and flat-panel detector are mounted on a translational arm, which is parked above the treatment unit when not in use. Upon descent, a rotational axis provides 210° of rotation for cone beam CT scans. Mechanical integrity of the system was evaluated over a 6-month period. Subsequent clinical commissioning included end-to-end testing of targeting performance and subjective image quality performance in phantoms. The system has been used to image 2 patients, 1 of whom received single-fraction radiosurgery and 1 who received 3 fractions, using a relocatable head frame. Images of phantoms demonstrated soft tissue contrast visibility and submillimeter spatial resolution. A contrast difference of 35 HU was easily detected at a calibration dose of 1.2 cGy (center of head phantom). The shape of the mechanical flex vs scan angle was highly reproducible and exhibited cone beam CT image guidance system was successfully adapted to a radiosurgery unit. The system is capable of producing high-resolution images of bone and soft tissue. The system is in clinical use and provides excellent image guidance without invasive frames. Copyright © 2013 Elsevier Inc. All rights reserved.

Image Guidance and Assessment of Radiation Induced Gene Therapy

National Research Council Canada - National Science Library

Pelizzari, Charles

2004-01-01

Image guidance and assessment techniques are being developed for combined radiation/gene therapy, which utilizes a radiation-inducible gene promoter to cause expression of tumor necrosis factor alpha...

Research and application on imaging technology of line structure light based on confocal microscopy

Science.gov (United States)

Han, Wenfeng; Xiao, Zexin; Wang, Xiaofen

2009-11-01

In 2005, the theory of line structure light confocal microscopy was put forward firstly in China by Xingyu Gao and Zexin Xiao in the Institute of Opt-mechatronics of Guilin University of Electronic Technology. Though the lateral resolution of line confocal microscopy can only reach or approach the level of the traditional dot confocal microscopy. But compared with traditional dot confocal microscopy, it has two advantages: first, by substituting line scanning for dot scanning, plane imaging only performs one-dimensional scanning, with imaging velocity greatly improved and scanning mechanism simplified, second, transfer quantity of light is greatly improved by substituting detection hairline for detection pinhole, and low illumination CCD is used directly to collect images instead of photoelectric intensifier. In order to apply the line confocal microscopy to practical system, based on the further research on the theory of the line confocal microscopy, imaging technology of line structure light is put forward on condition of implementation of confocal microscopy. Its validity and reliability are also verified by experiments.

On-line monitoring of fluid bed granulation by photometric imaging.

Science.gov (United States)

Soppela, Ira; Antikainen, Osmo; Sandler, Niklas; Yliruusi, Jouko

2014-11-01

This paper introduces and discusses a photometric surface imaging approach for on-line monitoring of fluid bed granulation. Five granule batches consisting of paracetamol and varying amounts of lactose and microcrystalline cellulose were manufactured with an instrumented fluid bed granulator. Photometric images and NIR spectra were continuously captured on-line and particle size information was extracted from them. Also key process parameters were recorded. The images provided direct real-time information on the growth, attrition and packing behaviour of the batches. Moreover, decreasing image brightness in the drying phase was found to indicate granule drying. The changes observed in the image data were also linked to the moisture and temperature profiles of the processes. Combined with complementary process analytical tools, photometric imaging opens up possibilities for improved real-time evaluation fluid bed granulation. Furthermore, images can give valuable insight into the behaviour of excipients or formulations during product development. Copyright © 2014 Elsevier B.V. All rights reserved.

SU-E-P-41: Imaging Coordination of Cone Beam CT, On-Board Image Conjunction with Optical Image Guidance for SBRT Treatment with Respiratory Motion Management

International Nuclear Information System (INIS)

Liu, Y; Campbell, J

2015-01-01

Purpose: To spare normal tissue for SBRT lung/liver patients, especially for patients with significant tumor motion, image guided respiratory motion management has been widely implemented in clinical practice. The purpose of this study was to evaluate imaging coordination of cone beam CT, on-board X-ray image conjunction with optical image guidance for SBRT treatment with motion management. Methods: Currently in our clinic a Varian Novlis Tx was utilized for treating SBRT patients implementing CBCT. A BrainLAB X-ray ExacTrac imaging system in conjunction with optical guidance was primarily used for SRS patients. CBCT and X-ray imaging system were independently calibrated with 1.0 mm tolerance. For SBRT lung/liver patients, the magnitude of tumor motion was measured based-on 4DCT and the measurement was analyzed to determine if patients would be beneficial with respiratory motion management. For patients eligible for motion management, an additional CT with breath holding would be scanned and used as primary planning CT and as reference images for Cone beam CT. During the SBRT treatment, a CBCT with pause and continuing technology would be performed with patients holding breath, which may require 3–4 partially scanned CBCT to combine as a whole CBCT depending on how long patients capable of holding breath. After patients being setup by CBCT images, the ExactTrac X-ray imaging system was implemented with patients’ on-board X-ray images compared to breath holding CT-based DRR. Results: For breath holding patients SBRT treatment, after initially localizing patients with CBCT, we then position patients with ExacTrac X-ray and optical imaging system. The observed deviations of real-time optical guided position average at 3.0, 2.5 and 1.5 mm in longitudinal, vertical and lateral respectively based on 35 treatments. Conclusion: The respiratory motion management clinical practice improved our physician confidence level to give tighter tumor margin for sparing normal

DESIGN OF ROBUST COMMAND TO LINE-OF-SIGHT GUIDANCE LAW: A FUZZY ADAPTIVE APPROACH

Directory of Open Access Journals (Sweden)

ESMAIL SADEGHINASAB

2016-11-01

Full Text Available In this paper, the design of command to line-of-sight (CLOS missile guidance law is addressed. Taking a three dimensional guidance model, the tracking control problem is formulated. To solve the target tracking problem, the feedback linearization controller is first designed. Although such control scheme possesses the simplicity property, but it presents the acceptable performance only in the absence of perturbations. In order to ensure the robustness properties against model uncertainties, a fuzzy adaptive algorithm is proposed with two parts including a fuzzy (Mamdani system, whose rules are constructed based on missile guidance, and a so-called rule modifier to compensate the fuzzy rules, using the negative gradient method. Compared with some previous works, such control strategy provides a faster time response without large control efforts. The performance of feedback linearization controller is also compared with that of fuzzy adaptive strategy via various simulations.

What is the value of Image guidance in external beam radiotherapy?

International Nuclear Information System (INIS)

Kron, Tomas

2010-01-01

Full text: Image guided radiation therapy (lGRT) has become available in many radiotherapy centres in Australia. It is intuitive that frequent imaging of the patient with a modality that identifies the target directly at the time of treatment delivery should benefit patients. However, TGRT is also associated with increased cost for equipment, associated training, quality assurance and imaging time. The Trans Tasman Radiation Oncology Group (TROG) has been contracted by the Australian Commonwealth Department of Health and Ageing (DoHA) to investigate a framework that could be applied to establish a cost/utility assessment of IGRT. The present work aims to develop a study that can test this for daily image guidance of prostate cancer patients. Approach Thirty intermediate risk prostate cancer patients treated at ten or more radiotherapy centres in Australia will be invited to participate. Their treatment as per local practice will not be modified; however two additional treatment plans will be created with margins that would reflect a typical margin appropriate for a treatment delivery with and without daily image guidance. Patients will be stratified for volumetric versus planar orthogonal imaging and for IMRT or conformal approaches. The outcome will be a comparison of dose volume histograms for critical structures based on equal target coverage in all plans.

First use of a truly-hybrid x-ray/MR imaging system for guidance of brain biopsy

International Nuclear Information System (INIS)

Fahrig, R.; Daniel, B.L.; Butts, K.; Pelc, N.J.; Heit, G.; Wen, Z.

2003-01-01

The use of a new hybrid imaging system for guidance of a brain biopsy is described. The system combines the strengths of MRI (soft-tissue contrast, arbitrary plane selection) with those of x-ray fluoroscopy (high-resolution real-time projection images, clear portrayal of bony structures) and allows switching between the imaging modalities without moving the patient. The biopsy was carried out using x-ray guidance for direction of the needle through the foramen ovale and MR guidance to target the soft-tissue lesion. Appropriate samples were acquired. The system could be particularly effective for guidance of those cases where motion, swelling, resection and other intra-operative anatomical changes cannot be accounted for using traditional stereotactic-based imaging approaches. (author)

76 FR 51993 - Draft Guidance for Industry on Standards for Clinical Trial Imaging Endpoints; Availability

Science.gov (United States)

2011-08-19

... clinical trials of therapeutic drugs and biological products. The draft guidance describes standards... important imaging endpoint is used in a clinical trial of a therapeutic drug or biological product... Services to the Chairman of [[Page 51994

Percutaneous Thermal Ablation with Ultrasound Guidance. Fusion Imaging Guidance to Improve Conspicuity of Liver Metastasis

Energy Technology Data Exchange (ETDEWEB)

Hakime, Antoine, E-mail: thakime@yahoo.com; Yevich, Steven; Tselikas, Lambros; Deschamps, Frederic [Gustave Roussy - Cancer Campus, Interventional Radiology Department (France); Petrover, David [Imagerie Médicale Paris Centre, IMPC (France); Baere, Thierry De [Gustave Roussy - Cancer Campus, Interventional Radiology Department (France)

2017-05-15

PurposeTo assess whether fusion imaging-guided percutaneous microwave ablation (MWA) can improve visibility and targeting of liver metastasis that were deemed inconspicuous on ultrasound (US).Materials and MethodsMWA of liver metastasis not judged conspicuous enough on US was performed under CT/US fusion imaging guidance. The conspicuity before and after the fusion imaging was graded on a five-point scale, and significance was assessed by Wilcoxon test. Technical success, procedure time, and procedure-related complications were evaluated.ResultsA total of 35 patients with 40 liver metastases (mean size 1.3 ± 0.4 cm) were enrolled. Image fusion improved conspicuity sufficiently to allow fusion-targeted MWA in 33 patients. The time required for image fusion processing and tumors’ identification averaged 10 ± 2.1 min (range 5–14). Initial conspicuity on US by inclusion criteria was 1.2 ± 0.4 (range 0–2), while conspicuity after localization on fusion imaging was 3.5 ± 1 (range 1–5, p < 0.001). Technical success rate was 83% (33/40) in intention-to-treat analysis and 100% in analysis of treated tumors. There were no major procedure-related complications.ConclusionsFusion imaging broadens the scope of US-guided MWA to metastasis lacking adequate conspicuity on conventional US. Fusion imaging is an effective tool to increase the conspicuity of liver metastases that were initially deemed non visualizable on conventional US imaging.

Compton scatter imaging: A promising modality for image guidance in lung stereotactic body radiation therapy.

Science.gov (United States)

Redler, Gage; Jones, Kevin C; Templeton, Alistair; Bernard, Damian; Turian, Julius; Chu, James C H

2018-03-01

Lung stereotactic body radiation therapy (SBRT) requires delivering large radiation doses with millimeter accuracy, making image guidance essential. An approach to forming images of patient anatomy from Compton-scattered photons during lung SBRT is presented. To investigate the potential of scatter imaging, a pinhole collimator and flat-panel detector are used for spatial localization and detection of photons scattered during external beam therapy using lung SBRT treatment conditions (6 MV FFF beam). MCNP Monte Carlo software is used to develop a model to simulate scatter images. This model is validated by comparing experimental and simulated phantom images. Patient scatter images are then simulated from 4DCT data. Experimental lung tumor phantom images have sufficient contrast-to-noise to visualize the tumor with as few as 10 MU (0.5 s temporal resolution). The relative signal intensity from objects of different composition as well as lung tumor contrast for simulated phantom images agree quantitatively with experimental images, thus validating the Monte Carlo model. Scatter images are shown to display high contrast between different materials (lung, water, bone). Simulated patient images show superior (~double) tumor contrast compared to MV transmission images. Compton scatter imaging is a promising modality for directly imaging patient anatomy during treatment without additional radiation, and it has the potential to complement existing technologies and aid tumor tracking and lung SBRT image guidance. © 2018 American Association of Physicists in Medicine.

Evaluation of alignment error due to a speed artifact in stereotactic ultrasound image guidance

International Nuclear Information System (INIS)

Salter, Bill J; Wang, Brian; Szegedi, Martin W; Rassiah-Szegedi, Prema; Shrieve, Dennis C; Cheng, Roger; Fuss, Martin

2008-01-01

Ultrasound (US) image guidance systems used in radiotherapy are typically calibrated for soft tissue applications, thus introducing errors in depth-from-transducer representation when used in media with a different speed of sound propagation (e.g. fat). This error is commonly referred to as the speed artifact. In this study we utilized a standard US phantom to demonstrate the existence of the speed artifact when using a commercial US image guidance system to image through layers of simulated body fat, and we compared the results with calculated/predicted values. A general purpose US phantom (speed of sound (SOS) = 1540 m s -1 ) was imaged on a multi-slice CT scanner at a 0.625 mm slice thickness and 0.5 mm x 0.5 mm axial pixel size. Target-simulating wires inside the phantom were contoured and later transferred to the US guidance system. Layers of various thickness (1-8 cm) of commercially manufactured fat-simulating material (SOS = 1435 m s -1 ) were placed on top of the phantom to study the depth-related alignment error. In order to demonstrate that the speed artifact is not caused by adding additional layers on top of the phantom, we repeated these measurements in an identical setup using commercially manufactured tissue-simulating material (SOS = 1540 m s -1 ) for the top layers. For the fat-simulating material used in this study, we observed the magnitude of the depth-related alignment errors resulting from the speed artifact to be 0.7 mm cm -1 of fat imaged through. The measured alignment errors caused by the speed artifact agreed with the calculated values within one standard deviation for all of the different thicknesses of fat-simulating material studied here. We demonstrated the depth-related alignment error due to the speed artifact when using US image guidance for radiation treatment alignment and note that the presence of fat causes the target to be aliased to a depth greater than it actually is. For typical US guidance systems in use today, this will

Evaluation of alignment error due to a speed artifact in stereotactic ultrasound image guidance.

Science.gov (United States)

Salter, Bill J; Wang, Brian; Szegedi, Martin W; Rassiah-Szegedi, Prema; Shrieve, Dennis C; Cheng, Roger; Fuss, Martin

2008-12-07

Ultrasound (US) image guidance systems used in radiotherapy are typically calibrated for soft tissue applications, thus introducing errors in depth-from-transducer representation when used in media with a different speed of sound propagation (e.g. fat). This error is commonly referred to as the speed artifact. In this study we utilized a standard US phantom to demonstrate the existence of the speed artifact when using a commercial US image guidance system to image through layers of simulated body fat, and we compared the results with calculated/predicted values. A general purpose US phantom (speed of sound (SOS) = 1540 m s(-1)) was imaged on a multi-slice CT scanner at a 0.625 mm slice thickness and 0.5 mm x 0.5 mm axial pixel size. Target-simulating wires inside the phantom were contoured and later transferred to the US guidance system. Layers of various thickness (1-8 cm) of commercially manufactured fat-simulating material (SOS = 1435 m s(-1)) were placed on top of the phantom to study the depth-related alignment error. In order to demonstrate that the speed artifact is not caused by adding additional layers on top of the phantom, we repeated these measurements in an identical setup using commercially manufactured tissue-simulating material (SOS = 1540 m s(-1)) for the top layers. For the fat-simulating material used in this study, we observed the magnitude of the depth-related alignment errors resulting from the speed artifact to be 0.7 mm cm(-1) of fat imaged through. The measured alignment errors caused by the speed artifact agreed with the calculated values within one standard deviation for all of the different thicknesses of fat-simulating material studied here. We demonstrated the depth-related alignment error due to the speed artifact when using US image guidance for radiation treatment alignment and note that the presence of fat causes the target to be aliased to a depth greater than it actually is. For typical US guidance systems in use today, this will

Robotic needle steering: design, modeling, planning, and image guidance

NARCIS (Netherlands)

Cowan, Noah J.; Goldberg, Ken; Chirikjian, Gregory S.; Fichtinger, Gabor; Alterovitz, Ron; Reed, Kyle B.; Kallem, Vinutha; Misra, Sarthak; Park, Wooram; Okamura, Allison M.; Rosen, Jacob; Hannaford, Blake; Satava, Richard M.

2010-01-01

This chapter describes how advances in needle design, modeling, planning, and image guidance make it possible to steer flexible needles from outside the body to reach specified anatomical targets not accessible using traditional needle insertion methods. Steering can be achieved using a variety of

Improvement in dose escalation using off-line and on-line image feedback in the intensity modulated beam design for prostate cancer treatment

International Nuclear Information System (INIS)

Yan, D.; Birkner, M.; Nuesslin, F.; Wong, J.; Martinez, A.

2001-01-01

Purpose: To test the capability of dose escalation in the IMRT process where the organ/patient temporal geometric variation, measured using either off-line or on-line treatment CT and portal images, are adapted for the optimal design of intensity modulated beam. Materials and Methods: Retrospective study was performed on five prostate cancer patients with multiple CT scans (14∼17/patient) and daily portal images obtained during the treatment course. These images were used to determine the displacements of each subvolume in the organs of interest caused by the daily patient setup and internal organ motion/deformation. The temporal geometric information was processed in order of treatment time and fed into an inverse planning system. The inverse planning engine was specifically implemented to adapt the design of intensity modulated beam to the temporal subvolume displacement and patient internal density changes. Three image feedback strategies were applied to each patient and evaluated with respect to the capability of safe dose escalation. The first one is off-line image feedback, which designs the beam intensity based on the patient images measured within the first week of treatment. The second is an on-line 'the target of the day' strategy, which designs the beam intensity in daily bases by using 'the image of the day' alone. The last one is also the on-line based. However, it designs the instantaneous beam intensity based on also dose distribution in each organ of interest received prior to the current treatment. For each of the treatment strategies, the minimum dose delivered to the CTV was determined by applying the identical normal tissue constraints of partial dose/volumes. This minimum dose was used to represent the treatment dose for each patient. Results: The off-line strategy appears feasible after 5 days of image feedback. The average treatment dose among the patients can be 10% higher than the one in the conventional IMRT treatment where the inverse

On-line image guidance for frameless stereotactic radiotherapy of lung malignancies by cone beam CT: Comparison between target localization and alignment on bony anatomy

International Nuclear Information System (INIS)

Masi, Laura; Casamassima, Franco; Menichelli, Claudia; Pasciuti, Katia; Doro, Raffaela; Polli, Caterina; D'imporzano, Elena; Bonucci, Ivano

2008-01-01

Introduction. Free-breathing stereotactic radiotherapy for lung malignancies requires reliable prediction of respiratory motion and accurate target localization. A protocol was adopted for reproducibility and reduction of respiratory motion and for target localization by CBCT image guidance. Tumor respiratory displacements and tumor positioning errors relative to bony anatomy alignment are analyzed. Materials and method. Image guided SRT was performed for 99 lung malignancies. Two groups of patients were considered: group A did not perform any breathing control; group B controlled visually their respiratory cycle and volumes on an Active Breathing Coordinator (ABC) monitor during the acquisition of simulation CT and CBCT, and treatment delivery. GTV on end inhale and exhale CT data sets were fused in an ITV and the extent of tumor motion evaluated between these 2 phases. A pre-treatment CBCT was acquired and aligned to the reference CT using bony anatomy; for tumor positioning the ITV contour on the reference CT was matched to the visible tumor on CBCT. Interobserver variability of tumor positioning was evaluated. ITV and CBCT tumor dimensions were compared. Results. 3D tumor breathing displacement (mean±SD) was significantly higher for group A (14.7±9.9 mm) than for group B (4.7±3.1 mm). The detected differences between tumor and bony structure alignment below 3 mm were 68% for group B and 45% for group A, reaching statistical significance. Interobserver variability was 1.7±1.1 mm (mean±SD). Dimensions of tumor image on CBCT were consistent with ITV dimensions for group B (max difference 14%). Conclusions. The adopted protocol seems effective in reducing respiratory internal movements and margin. Tumor positioning errors relative to bony anatomy are also reduced. However bony anatomy as a surrogate of the target may still lead to some relevant positioning errors. Target visualization on CBCT is essential for an accurate localization in lung SRT

Registration of airborne LiDAR data and aerial images based on straight lines and POS data

Science.gov (United States)

Du, Quanye; Xu, Biao; Cao, Hui

2009-10-01

This paper presents a registration method which based on straight lines primitive. Firstly, 2D straight lines are extracted from aerial images using Canny operator and straight line fitting. In the similar way, 3D straight lines are extracted from LiDAR range images which derive from laser scanning point cloud. Secondly, 3D straight lines are projected to aerial images using collinearity equations and Position and Orientation System (POS) data. Then the corresponding lines are determined by straight line error. At last, each image's new exterior orientation elements are calculated by generalized point (straight line) photogrammetry.

Registration of Urban Aerial Image and LiDAR Based on Line Vectors

Directory of Open Access Journals (Sweden)

Qinghong Sheng

2017-09-01

Full Text Available In a traditional registration of a single aerial image with airborne light detection and ranging (LiDAR data using linear features that regard line direction as a control or linear features as constraints in the solution, lacking the constraint of linear position leads to the error propagation of the adjustment model. To solve this problem, this paper presents a line vector-based registration mode (LVR in which image rays and LiDAR lines are expressed by a line vector that integrates the line direction and the line position. A registration equation of line vector is set up by coplanar imaging rays and corresponding control lines. Three types of datasets consisting of synthetic, theInternational Society for Photogrammetry and Remote Sensing (ISPRS test project, and real aerial data are used. A group of progressive experiments is undertaken to evaluate the robustness of the LVR. Experimental results demonstrate that the integrated line direction and the line position contributes a great deal to the theoretical and real accuracies of the unknowns, as well as the stability of the adjustment model. This paper provides a new suggestion that, for a single image and LiDAR data, registration in urban areas can be accomplished by accommodating rich line features.

Autonomous aerial vehicles : guidance, control, signal and image processing platform

International Nuclear Information System (INIS)

Al-Jarrah, M.; Adiansyah, S.; Marji, Z. M.; Chowdhury, M. S.

2011-01-01

The use of unmanned systems is gaining momentum in civil applications after successful use by the armed forces around the globe. Autonomous aerial vehicles are important for providing assistance in monitoring highways, power grid lines, borders, and surveillance of critical infrastructures. It is envisioned that cargo shipping will be completely handled by UAVs by the 2025. Civil use of unmanned autonomous systems brings serious challenges. The need for cost effectiveness, reliability, operation simplicity, safety, and cooperation with human and with other agents are among these challenges. Aerial vehicles operating in the civilian aerospace is the ultimate goal which requires these systems to achieve the reliability of manned aircraft while maintaining their cost effectiveness. In this presentation the development of an autonomous fixed and rotary wing aerial vehicle will be discussed. The architecture of the system from the mission requirements to low level auto pilot control laws will be discussed. Trajectory tracking and path following guidance and control algorithms commonly used and their implementation using of the shelf low cost components will be presented. Autonomous takeo? landing is a key feature that was implemented onboard the vehicle to complete its degree of autonomy. This is implemented based on accurate air-data system designed and fused with sonar measurements, INS/GPS measurements, and vector field method guidance laws. The outcomes of the proposed research is that the AUS-UAV platform named MAZARI is capable of autonomous takeoff and landing based on a pre scheduled flight path using way point navigation and sensor fusion of the inertial navigation system (INS) and global positioning system (GPS). Several technologies need to be mastered when developing a UAV. The navigation task and the need to fuse sensory information to estimate the location of the vehicle is critical to successful autonomous vehicle. Currently extended Kalman filtering is

On-line MRI guidance for Radiotherapy

NARCIS (Netherlands)

Crijns, S.P.M.

2013-01-01

Image-guided radiotherapy has the potential to increase success of treatment by decreasing uncertainties concerning tumour position and shape. MRI is the modality of choice when it comes to imaging for tumour delineation and characterisation, set-up correction, treatment plan adaptation, response

Direct aperture deformation: An interfraction image guidance strategy

International Nuclear Information System (INIS)

Feng Yuanming; Castro-Pareja, Carlos; Shekhar, Raj; Yu, Cedric

2006-01-01

A new scheme, called direct aperture deformation (DAD), for online correction of interfraction geometric uncertainties under volumetric imaging guidance is presented. Using deformable image registration, the three-dimensional geometric transformation matrix can be derived that associates the planning image set and the images acquired on the day of treatment. Rather than replanning or moving the patient, we use the deformation matrix to morph the treatment apertures as a potential online correction method. A proof-of-principle study using an intensity-modulated radiation therapy plan for a prostate cancer patient was conducted. The method, procedure, and algorithm of DAD are described. The dose-volume histograms from the original plan, reoptimized plan, and rigid-body translation plan are compared with the ones from the DAD plan. The study showed the feasibility of the DAD as a general method for both target dislocation and deformation. As compared with using couch translation to move the patient, DAD is capable of correcting both target dislocation and deformations. As compared with reoptimization, online correction using the DAD scheme could be completed within a few minutes rather than tens of minutes and the speed gain would be at a very small cost of plan quality

Impact of Image Guidance on Outcomes After External Beam Radiotherapy for Localized Prostate Cancer

International Nuclear Information System (INIS)

Kupelian, Patrick A.; Willoughby, Twyla R.; Reddy, Chandana A.; Klein, Eric A.; Mahadevan, Arul

2008-01-01

Purpose: To verify whether rectal distention at the time of planning impacts outcomes in patients with localized prostate cancer treated with daily image guidance. Methods and Materials: Between 1998 and 2002, a total of 488 prostate cancer patients were treated with intensity-modulated radiotherapy. The radiation dose was 70 Gy delivered at 2.5 Gy per fraction in all cases. All cases were treated with a 4-mm margin posteriorly. In all cases the total rectal volume documented on the CT scan was used for treatment planning. No special bowel preparation instructions were given, either for the simulation or the daily treatments. Before each daily treatment, alignment of the prostate was performed with the B-mode acquisition and targeting (BAT) transabdominal ultrasound system. The median follow-up for all 488 patients was 60 months (range, 24-96 months). Results: For all patients the biochemical relapse-free survival (bRFS) rate at 5 years was 86%. The 5-year bRFS rate for the rectal distention 3 , 50 to 3 , and ≥100 cm 3 groups was 90%, 83%, and 85%, respectively (p = 0.18). To adjust for other potential variables affecting bRFS rates, a multivariate time-to-failure analysis using the Cox proportional hazards model was performed. Rectal distention was not an independent predictor of biochemical failure on multivariate analysis (p = 0.80). Rectal distention was not a predictor of rectal or urinary toxicity. Conclusion: The use of daily image guidance eliminates errors such as rectal distention at the initial planning stage that can affect outcomes after radiotherapy for localized prostate cancer

CT imaging vs. traditional radiographic imaging for evaluating Harris Lines in tibiae

DEFF Research Database (Denmark)

Primeau, Charlotte; Jakobsen, Lykke Schrøder; Lynnerup, Niels

2016-01-01

This paper is the first to systematically investigate computer tomography (CT) images vs. ordinary flat plane radiography for evaluating Harris Lines (HL) on tibiae. Harris Lines are traditionally investigated using radiographic images and recorded as either present or absent, or by counting...

Virtual and augmented medical imaging environments: enabling technology for minimally invasive cardiac interventional guidance.

Science.gov (United States)

Linte, Cristian A; White, James; Eagleson, Roy; Guiraudon, Gérard M; Peters, Terry M

2010-01-01

Virtual and augmented reality environments have been adopted in medicine as a means to enhance the clinician's view of the anatomy and facilitate the performance of minimally invasive procedures. Their value is truly appreciated during interventions where the surgeon cannot directly visualize the targets to be treated, such as during cardiac procedures performed on the beating heart. These environments must accurately represent the real surgical field and require seamless integration of pre- and intra-operative imaging, surgical tracking, and visualization technology in a common framework centered around the patient. This review begins with an overview of minimally invasive cardiac interventions, describes the architecture of a typical surgical guidance platform including imaging, tracking, registration and visualization, highlights both clinical and engineering accuracy limitations in cardiac image guidance, and discusses the translation of the work from the laboratory into the operating room together with typically encountered challenges.

[Anterior guidance in complete dentures].

Science.gov (United States)

Dubreuil, J; Trevelo, A

1990-01-01

Although the anterior guidance in complete dentures is not really a guide, the arrangement of the anterior maxillary and mandibular prosthetic teeth, defines a propulsive line called the virtual anterior guidance, a part from the cinematic criterias. The influence of this guide on cuspal movement is superior, in all mandibular points, to the influence of the condylar pathway. If this line is not respected, the practitioner may have to do excessive grindings during occlusal adjustments.

Registration of Aerial Image with Airborne LiDAR Data Based on Plücker Line

Directory of Open Access Journals (Sweden)

SHENG Qinghong

2015-07-01

Full Text Available Registration of aerial image with airborne LiDAR data is a key to feature extraction. A registration model based on Plücker line is proposed. The relative position and attitude relationship between the conjugate lines in LiDAR and image is determined based on Plücker linear equation, which describes line transformation in space, then coplanarity condition equation is established. Finally, coordinate transformation between image point and corresponding LiDAR point is achieved by the spiral movement of Plücker lines in the image. The registration model of Plücker linear coplanarity condition equation is simple, and jointly describes the rotation and translation to avoid coupling error between them, so the accuracy is approved. This research provides technical support for high-quality earth spatial information acquisition.

Remote Sensing Image Registration with Line Segments and Their Intersections

Directory of Open Access Journals (Sweden)

Chengjin Lyu

2017-05-01

Full Text Available Image registration is a basic but essential step for remote sensing image processing, and finding stable features in multitemporal images is one of the most considerable challenges in the field. The main shape contours of artificial objects (e.g., roads, buildings, farmlands, and airports can be generally described as a group of line segments, which are stable features, even in images with evident background changes (e.g., images taken before and after a disaster. In this study, a registration method that uses line segments and their intersections is proposed for multitemporal remote sensing images. First, line segments are extracted in image pyramids to unify the scales of the reference image and the test image. Then, a line descriptor based on the gradient distribution of local areas is constructed, and the segments are matched in image pyramids. Lastly, triplets of intersections of matching lines are selected to estimate affine transformation between two images. Additional corresponding intersections are provided based on the estimated transformation, and an iterative process is adopted to remove outliers. The performance of the proposed method is tested on a variety of optical remote sensing image pairs, including synthetic and real data. Compared with existing methods, our method can provide more accurate registration results, even in images with significant background changes.

Dehazed Image Quality Assessment by Haze-Line Theory

Science.gov (United States)

Song, Yingchao; Luo, Haibo; Lu, Rongrong; Ma, Junkai

2017-06-01

Images captured in bad weather suffer from low contrast and faint color. Recently, plenty of dehazing algorithms have been proposed to enhance visibility and restore color. However, there is a lack of evaluation metrics to assess the performance of these algorithms or rate them. In this paper, an indicator of contrast enhancement is proposed basing on the newly proposed haze-line theory. The theory assumes that colors of a haze-free image are well approximated by a few hundred distinct colors, which form tight clusters in RGB space. The presence of haze makes each color cluster forms a line, which is named haze-line. By using these haze-lines, we assess performance of dehazing algorithms designed to enhance the contrast by measuring the inter-cluster deviations between different colors of dehazed image. Experimental results demonstrated that the proposed Color Contrast (CC) index correlates well with human judgments of image contrast taken in a subjective test on various scene of dehazed images and performs better than state-of-the-art metrics.

LINE-BASED REGISTRATION OF DSM AND HYPERSPECTRAL IMAGES

Directory of Open Access Journals (Sweden)

J. Avbelj

2013-04-01

Full Text Available Data fusion techniques require a good registration of all the used datasets. In remote sensing, images are usually geo-referenced using the GPS and IMU data. However, if more precise registration is required, image processing techniques can be employed. We propose a method for multi-modal image coregistration between hyperspectral images (HSI and digital surface models (DSM. The method is divided in three parts: object and line detection of the same object in HSI and DSM, line matching and determination of transformation parameters. Homogeneous coordinates are used to implement matching and adjustment of transformation parameters. The common object in HSI and DSM are building boundaries. They have apparent change in height and material, that can be detected in DSM and HSI, respectively. Thus, before the matching and transformation parameter computation, building outlines are detected and adjusted in HSI and DSM. We test the method on a HSI and two DSM, using extracted building outbounds and for comparison also extracted lines with a line detector. The results show that estimated building boundaries provide more line assignments, than using line detector.

Reliable Line Matching Algorithm for Stereo Images with Topological Relationship

Directory of Open Access Journals (Sweden)

WANG Jingxue

2017-11-01

Full Text Available Because of the lack of relationships between matching line and adjacent lines in the process of individual line matching, and the weak reliability of the individual line descriptor facing on discontinue texture, this paper presents a reliable line matching algorithm for stereo images with topological relationship. The algorithm firstly generates grouped line pairs from lines extracted from the reference image and searching image according to the basic topological relationships such as distance and angle between the lines. Then it takes the grouped line pairs as matching primitives, and matches these grouped line pairs by using epipolar constraint, homography constraint, quadrant constraint and gray correlation constraint of irregular triangle in order. And finally, it resolves the corresponding line pairs into two pairs of corresponding individual lines, and obtains one to one matching results after the post-processing of integrating, fitting, and checking. This paper adopts digital aerial images and close-range images with typical texture features to deal with the parameter analysis and line matching, and the experiment results demonstrate that the proposed algorithm in this paper can obtain reliable line matching results.

Dose Matters: FDA's Guidance on Children's X-rays

Science.gov (United States)

... Consumer Updates Dose Matters: FDA's Guidance on Children's X-rays Share Tweet Linkedin Pin it More sharing options ... exposure during medical procedures. The level of ionizing radiation from X-ray imaging is generally very low, but can ...

MR imaging guidance and monitoring of focal thermotherapies. A review

International Nuclear Information System (INIS)

Mueller-Lisse, U.G.; California Univ., San Francisco, CA; Heuck, A.F.

1998-01-01

Minimally invasive thermotherapies for focal tissue destruction on the basis of laser-, microwave-, focused ultrasound-, or cryogeninduced changes of tissue temperature represent an alternative to surgical tissue ablation, particularly in the treatment of tumors. The thermotherapy modalities listed necessitate indirect guidance and monitoring, since they often do not lend themselves to immediate visual control. In the brain, in head and neck tumors, in the liver, and in the prostate, MRI reliably and accurately delineates both the positions of interstitial thermotherapy applicators and - in contrast-enhanced, T1-weighted images - the perfusion defects in tissue necrosis induced by thermotherapy. The transfer of results of in-vitro and in-vivo model studies to assess interstitial temperature and lesion development during thermotherapy to the actual treatment of patients, however, is still in an initial phase. Further development of both rapid MRI sequences and MRI scanners suited for interventions will show how far treatment systems and guidance systems can be adapted to one another. (orig.) [de

Optimization of X-ray phase-contrast imaging based on in-line holography

International Nuclear Information System (INIS)

Wu Xizeng; Liu Hong; Yan Aimin

2005-01-01

This paper introduces a newly conceived formalism for clinical in-line phase-contrast X-ray imaging. The new formalism applies not only to ideal 'thin' objects analyzed in previous studies, but also applies to the real-world tissues used in actual clinical practice. Moreover we have identified the four clinically important factors that affect phase-contrast characteristics. These factors are: (1) body part attenuation (2) the spatial coherence of incident X-rays from an X-ray tube (3) the polychromatic nature of the X-ray source and (4) radiation dose to patients for clinical applications. Techniques of phase image-reconstruction based on the new X-ray in-line holography theory are discussed. Numerical simulations are described which were used to validate the theory. The design parameters of an optimal clinical phase-contrast mammographic imaging system which were determined based on the new theory, and validated in the simulations, are presented. The theory, image reconstruction algorithms, and numerical simulation techniques presented in this paper can be applied widely to clinical diagnostic X-ray imaging applications

Ground-Wave Propagation Effects on Transmission Lines through Error Images

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Uribe-Campos Felipe Alejandro

2014-07-01

Full Text Available Electromagnetic transient calculation of overhead transmission lines is strongly influenced by the natural resistivity of the ground. This varies from 1-10K (Ω·m depending on several media factors and on the physical composition of the ground. The accuracy on the calculation of a system transient response depends in part in the ground return model, which should consider the line geometry, the electrical resistivity and the frequency dependence of the power source. Up to date, there are only a few reports on the specialized literature about analyzing the effects produced by the presence of an imperfectly conducting ground of transmission lines in a transient state. A broad range analysis of three of the most often used ground-return models for calculating electromagnetic transients of overhead transmission lines is performed in this paper. The behavior of modal propagation in ground is analyzed here into effects of first and second order. Finally, a numerical tool based on relative error images is proposed in this paper as an aid for the analyst engineer to estimate the incurred error by using approximate ground-return models when calculating transients of overhead transmission lines.

Improvement in toxicity in high risk prostate cancer patients treated with image-guided intensity-modulated radiotherapy compared to 3D conformal radiotherapy without daily image guidance.

Science.gov (United States)

Sveistrup, Joen; af Rosenschöld, Per Munck; Deasy, Joseph O; Oh, Jung Hun; Pommer, Tobias; Petersen, Peter Meidahl; Engelholm, Svend Aage

2014-02-04

Image-guided radiotherapy (IGRT) facilitates the delivery of a very precise radiation dose. In this study we compare the toxicity and biochemical progression-free survival between patients treated with daily image-guided intensity-modulated radiotherapy (IG-IMRT) and 3D conformal radiotherapy (3DCRT) without daily image guidance for high risk prostate cancer (PCa). A total of 503 high risk PCa patients treated with radiotherapy (RT) and endocrine treatment between 2000 and 2010 were retrospectively reviewed. 115 patients were treated with 3DCRT, and 388 patients were treated with IG-IMRT. 3DCRT patients were treated to 76 Gy and without daily image guidance and with 1-2 cm PTV margins. IG-IMRT patients were treated to 78 Gy based on daily image guidance of fiducial markers, and the PTV margins were 5-7 mm. Furthermore, the dose-volume constraints to both the rectum and bladder were changed with the introduction of IG-IMRT. The 2-year actuarial likelihood of developing grade > = 2 GI toxicity following RT was 57.3% in 3DCRT patients and 5.8% in IG-IMRT patients (p analysis, 3DCRT was associated with a significantly increased risk of developing grade > = 2 GI toxicity compared to IG-IMRT (p analysis there was no difference in biochemical progression-free survival between 3DCRT and IG-IMRT. The difference in toxicity can be attributed to the combination of the IMRT technique with reduced dose to organs-at-risk, daily image guidance and margin reduction.

Effects of load on the guidance of visual attention from working memory.

Science.gov (United States)

Zhang, Bao; Zhang, John X; Huang, Sai; Kong, Lingyue; Wang, Suiping

2011-12-08

An active recent line of research on working memory and attention has shown that the visual attention can be top-down guided by working memory contents. The present study examined whether the guidance effect is modulated by memory load, i.e., the amount of information maintained in working memory. In a set of three experiments, participants were asked to perform a visual search task while maintaining several objects in working memory. The memory-driven attentional guidance effect was observed in all experiments when there were spare working memory resources. When memory load was increased from one item to two items, there was no sign that the guidance effect was attenuated. When load was further increased to four items, the guidance effect disappeared completely, indicating a clear impact of memory load on attentional guidance. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spotting Separator Points at Line Terminals in Compressed Document Images for Text-line Segmentation

OpenAIRE

R, Amarnath; Nagabhushan, P.

2017-01-01

Line separators are used to segregate text-lines from one another in document image analysis. Finding the separator points at every line terminal in a document image would enable text-line segmentation. In particular, identifying the separators in handwritten text could be a thrilling exercise. Obviously it would be challenging to perform this in the compressed version of a document image and that is the proposed objective in this research. Such an effort would prevent the computational burde...

Dielectric image line groove antennas for millimeterwaves

Science.gov (United States)

Solbach, K.; Wolff, I.

Grooves in the ground plane of dielectric image lines are proposed as a new radiating structure. A figure is included showing the proposed groove structure as a discontinuity in a dielectric image line. A wave incident on the dielectric image line is partly reflected by the discontinuity, partly transmitted across the groove, and partly radiated into space above the line. In a travelling-wave antenna, a number of grooves are arranged below a dielectric guide, with spacings around one guide wavelength to produce a beam in the upper half space. A prescribed aperture distribution can be effected by tapering the series radiation resistance of the grooves. This can be done by adjusting the depths of the grooves with a constant width or by varying the widths of the grooves with a constant depth. Attention is also given to circular grooves. Here, the widths of the holes are chosen so that they can be considered as waveguides operating far below the cut-off frequency of the fundamental circular waveguide mode.

MICROARRAY IMAGE GRIDDING USING GRID LINE REFINEMENT TECHNIQUE

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V.G. Biju

2015-05-01

Full Text Available An important stage in microarray image analysis is gridding. Microarray image gridding is done to locate sub arrays in a microarray image and find co-ordinates of spots within each sub array. For accurate identification of spots, most of the proposed gridding methods require human intervention. In this paper a fully automatic gridding method which enhances spot intensity in the preprocessing step as per a histogram based threshold method is used. The gridding step finds co-ordinates of spots from horizontal and vertical profile of the image. To correct errors due to the grid line placement, a grid line refinement technique is proposed. The algorithm is applied on different image databases and results are compared based on spot detection accuracy and time. An average spot detection accuracy of 95.06% depicts the proposed method’s flexibility and accuracy in finding the spot co-ordinates for different database images.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure

Directory of Open Access Journals (Sweden)

Yuanqiang Ren

2017-05-01

Full Text Available Structural health monitoring (SHM of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures.

Evaluation of image-guidance protocols in the treatment of head and neck cancers

International Nuclear Information System (INIS)

Zeidan, Omar A.; Langen, Katja M.; Meeks, Sanford L.; Manon, Rafael R.; Wagner, Thomas H.; Willoughby, Twyla R.; Jenkins, D. Wayne; Kupelian, Patrick A.

2007-01-01

Purpose: The aim of this study was to assess the residual setup error of different image-guidance (IG) protocols in the alignment of patients with head and neck cancer. The protocols differ in the percentage of treatment fractions that are associated with image guidance. Using data from patients who were treated with daily IG, the residual setup errors for several different protocols are retrospectively calculated. Methods and Materials: Alignment data from 24 patients (802 fractions) treated with daily IG on a helical tomotherapy unit were analyzed. The difference between the daily setup correction and the setup correction that would have been made according to a specific protocol was used to calculate the residual setup errors for each protocol. Results: The different protocols are generally effective in reducing systematic setup errors. Random setup errors are generally not reduced for fractions that are not image guided. As a consequence, if every other treatment is image guided, still about 11% of all treatments (IG and not IG) are subject to three-dimensional setup errors of at least 5 mm. This frequency increases to about 29% if setup errors >3 mm are scored. For various protocols that require 15% to 31% of the treatments to be image guided, from 50% to 60% and from 26% to 31% of all fractions are subject to setup errors >3 mm and >5 mm, respectively. Conclusion: Residual setup errors reduce with increasing frequency of IG during the course of external-beam radiotherapy for head-and-neck cancer patients. The inability to reduce random setup errors for fractions that are not image guided results in notable residual setup errors

Improvement in toxicity in high risk prostate cancer patients treated with image-guided intensity-modulated radiotherapy compared to 3D conformal radiotherapy without daily image guidance

International Nuclear Information System (INIS)

Sveistrup, Joen; Rosenschöld, Per Munck af; Deasy, Joseph O; Oh, Jung Hun; Pommer, Tobias; Petersen, Peter Meidahl; Engelholm, Svend Aage

2014-01-01

Image-guided radiotherapy (IGRT) facilitates the delivery of a very precise radiation dose. In this study we compare the toxicity and biochemical progression-free survival between patients treated with daily image-guided intensity-modulated radiotherapy (IG-IMRT) and 3D conformal radiotherapy (3DCRT) without daily image guidance for high risk prostate cancer (PCa). A total of 503 high risk PCa patients treated with radiotherapy (RT) and endocrine treatment between 2000 and 2010 were retrospectively reviewed. 115 patients were treated with 3DCRT, and 388 patients were treated with IG-IMRT. 3DCRT patients were treated to 76 Gy and without daily image guidance and with 1–2 cm PTV margins. IG-IMRT patients were treated to 78 Gy based on daily image guidance of fiducial markers, and the PTV margins were 5–7 mm. Furthermore, the dose-volume constraints to both the rectum and bladder were changed with the introduction of IG-IMRT. The 2-year actuarial likelihood of developing grade > = 2 GI toxicity following RT was 57.3% in 3DCRT patients and 5.8% in IG-IMRT patients (p < 0.001). For GU toxicity the numbers were 41.8% and 29.7%, respectively (p = 0.011). On multivariate analysis, 3DCRT was associated with a significantly increased risk of developing grade > = 2 GI toxicity compared to IG-IMRT (p < 0.001, HR = 11.59 [CI: 6.67-20.14]). 3DCRT was also associated with an increased risk of developing GU toxicity compared to IG-IMRT. The 3-year actuarial biochemical progression-free survival probability was 86.0% for 3DCRT and 90.3% for IG-IMRT (p = 0.386). On multivariate analysis there was no difference in biochemical progression-free survival between 3DCRT and IG-IMRT. The difference in toxicity can be attributed to the combination of the IMRT technique with reduced dose to organs-at-risk, daily image guidance and margin reduction

Accuracy of image guidance using free-breathing cone-beam computed tomography for stereotactic lung radiotherapy.

Science.gov (United States)

Kamomae, Takeshi; Monzen, Hajime; Nakayama, Shinichi; Mizote, Rika; Oonishi, Yuuichi; Kaneshige, Soichiro; Sakamoto, Takashi

2015-01-01

Movement of the target object during cone-beam computed tomography (CBCT) leads to motion blurring artifacts. The accuracy of manual image matching in image-guided radiotherapy depends on the image quality. We aimed to assess the accuracy of target position localization using free-breathing CBCT during stereotactic lung radiotherapy. The Vero4DRT linear accelerator device was used for the examinations. Reference point discrepancies between the MV X-ray beam and the CBCT system were calculated using a phantom device with a centrally mounted steel ball. The precision of manual image matching between the CBCT and the averaged intensity (AI) images restructured from four-dimensional CT (4DCT) was estimated with a respiratory motion phantom, as determined in evaluations by five independent operators. Reference point discrepancies between the MV X-ray beam and the CBCT image-guidance systems, categorized as left-right (LR), anterior-posterior (AP), and superior-inferior (SI), were 0.33 ± 0.09, 0.16 ± 0.07, and 0.05 ± 0.04 mm, respectively. The LR, AP, and SI values for residual errors from manual image matching were -0.03 ± 0.22, 0.07 ± 0.25, and -0.79 ± 0.68 mm, respectively. The accuracy of target position localization using the Vero4DRT system in our center was 1.07 ± 1.23 mm (2 SD). This study experimentally demonstrated the sufficient level of geometric accuracy using the free-breathing CBCT and the image-guidance system mounted on the Vero4DRT. However, the inter-observer variation and systematic localization error of image matching substantially affected the overall geometric accuracy. Therefore, when using the free-breathing CBCT images, careful consideration of image matching is especially important.

3D/3D registration of coronary CTA and biplane XA reconstructions for improved image guidance

Energy Technology Data Exchange (ETDEWEB)

Dibildox, Gerardo, E-mail: g.dibildox@erasmusmc.nl; Baka, Nora; Walsum, Theo van [Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Punt, Mark; Aben, Jean-Paul [Pie Medical Imaging, 6227 AJ Maastricht (Netherlands); Schultz, Carl [Department of Cardiology, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Niessen, Wiro [Quantitative Imaging Group, Faculty of Applied Sciences, Delft University of Technology, 2628 CJ Delft, The Netherlands and Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands)

2014-09-15

Purpose: The authors aim to improve image guidance during percutaneous coronary interventions of chronic total occlusions (CTO) by providing information obtained from computed tomography angiography (CTA) to the cardiac interventionist. To this end, the authors investigate a method to register a 3D CTA model to biplane reconstructions. Methods: The authors developed a method for registering preoperative coronary CTA with intraoperative biplane x-ray angiography (XA) images via 3D models of the coronary arteries. The models are extracted from the CTA and biplane XA images, and are temporally aligned based on CTA reconstruction phase and XA ECG signals. Rigid spatial alignment is achieved with a robust probabilistic point set registration approach using Gaussian mixture models (GMMs). This approach is extended by including orientation in the Gaussian mixtures and by weighting bifurcation points. The method is evaluated on retrospectively acquired coronary CTA datasets of 23 CTO patients for which biplane XA images are available. Results: The Gaussian mixture model approach achieved a median registration accuracy of 1.7 mm. The extended GMM approach including orientation was not significantly different (P > 0.1) but did improve robustness with regards to the initialization of the 3D models. Conclusions: The authors demonstrated that the GMM approach can effectively be applied to register CTA to biplane XA images for the purpose of improving image guidance in percutaneous coronary interventions.

Integration of on-line imaging, plan adaptation and radiation delivery: proof of concept using digital tomosynthesis

International Nuclear Information System (INIS)

Mestrovic, Ante; Otto, Karl; Nichol, Alan; Clark, Brenda G

2009-01-01

The main objective of this manuscript is to propose a new approach to on-line adaptive radiation therapy (ART) in which daily image acquisition, plan adaptation and radiation delivery are integrated together and performed concurrently. A method is described in which on-line ART is performed based on intra-fractional digital tomosynthesis (DTS) images. Intra-fractional DTS images were reconstructed as the gantry rotated between treatment positions. An edge detection algorithm was used to automatically segment the DTS images as the gantry arrived at each treatment position. At each treatment position, radiation was delivered based on the treatment plan re-optimized for the most recent DTS image contours. To investigate the feasibility of this method, a model representing a typical prostate, bladder and rectum was used. To simulate prostate deformations, three clinically relevant, non-rigid deformations (small, medium and large) were modeled by systematically deforming the original anatomy. Using our approach to on-line ART, the original treatment plan was successfully adapted to arrive at a clinically acceptable plan for all three non-rigid deformations. In conclusion, we have proposed a new approach to on-line ART in which plan adaptation is performed based on intra-fractional DTS images. The study findings indicate that this approach can be used to re-optimize the original treatment plan to account for non-rigid anatomical deformations. The advantages of this approach are 1) image acquisition and radiation delivery are integrated in a single gantry rotation around the patient, reducing the treatment time, and 2) intra-fractional DTS images can be used to detect and correct for patient motion prior to the delivery of each beam (intra-fractional patient motion).

Extreme Tele-Echocardiography: Methodology for Remote Guidance of In-Flight Echocardiography Aboard the International Space Station

Science.gov (United States)

Martin, David S.; Borowski, Allan; Bungo, Michael W.; Gladding, Patrick; Greenberg, Neil; Hamilton, Doug; Levine, Benjamin D.; Lee, Stuart M.; Norwood, Kelly; Platts, Steven H.;

Accuracy of daily image guidance for hypofractionated liver radiotherapy with active breathing control

International Nuclear Information System (INIS)

Dawson, Laura A.; Eccles, Cynthia; Bissonnette, Jean-Pierre; Brock, Kristy K.

2005-01-01

Purpose: A six-fraction, high-precision radiotherapy protocol for unresectable liver cancer has been developed in which active breathing control (ABC) is used to immobilize the liver and daily megavoltage (MV) imaging and repositioning is used to decrease geometric uncertainties. We report the accuracy of setup in the first 20 patients consecutively treated using this approach. Methods and materials: After setup using conventional skin marks and lasers, orthogonal MV images were acquired with the liver immobilized using ABC. The images were aligned to reference digitally reconstructed radiographs using the diaphragm for craniocaudal (CC) alignment and the vertebral bodies for anterior-posterior (AP) and mediolateral (ML) alignment. Adjustments were made for positioning errors >3 mm. Verification imaging was repeated after repositioning to assess for residual positioning error. Offline image matching was conducted to determine the setup accuracy using this approach compared with the initial setup error before repositioning. Real-time beam's-eye-view MV movies containing an air-diaphragm interface were also evaluated. Results: A total of 405 images were evaluated from 20 patients. Repositioning occurred in 109 of 120 fractions because of offsets >3 mm. Three to eight beam angles, with up to four segments per field, were used for each isocenter. Breath holds of up to 27 s were used for imaging and treatment. The average time from the initial verification image to the last treatment beam was 21 min. Image guidance and repositioning reduced the population random setup errors (σ) from 6.5 mm (CC), 4.2 mm (ML), and 4.7 mm (AP) to 2.5 mm (CC), 2.8 mm (ML), and 2.9 mm (AP). The average individual random setup errors (σ) were reduced from 4.5 mm (CC), 3.2 mm (AP), and 2.5 mm (ML) to 2.2 mm (CC), 2.0 mm (AP), and 2.0 mm (ML). The standard deviation of the distribution of systematic deviations (Σ) was also reduced from 5.1 mm (CC), 3.4 mm (ML), and 3.1 mm (AP) to 1.4 mm (CC

Evaluation of the wavelet image two-line coder

DEFF Research Database (Denmark)

Rein, Stephan Alexander; Fitzek, Frank Hanns Paul; Gühmann, Clemens

2015-01-01

This paper introduces the wavelet image two-line (Wi2l) coding algorithm for low complexity compression of images. The algorithm recursively encodes an image backwards reading only two lines of a wavelet subband, which are read in blocks of 512 bytes from flash memory. It thus only requires very ...

Feature Extraction in Sequential Multimedia Images: with Applications in Satellite Images and On-line Videos

Science.gov (United States)

Liang, Yu-Li

Multimedia data is increasingly important in scientific discovery and people's daily lives. Content of massive multimedia is often diverse and noisy, and motion between frames is sometimes crucial in analyzing those data. Among all, still images and videos are commonly used formats. Images are compact in size but do not contain motion information. Videos record motion but are sometimes too big to be analyzed. Sequential images, which are a set of continuous images with low frame rate, stand out because they are smaller than videos and still maintain motion information. This thesis investigates features in different types of noisy sequential images, and the proposed solutions that intelligently combined multiple features to successfully retrieve visual information from on-line videos and cloudy satellite images. The first task is detecting supraglacial lakes above ice sheet in sequential satellite images. The dynamics of supraglacial lakes on the Greenland ice sheet deeply affect glacier movement, which is directly related to sea level rise and global environment change. Detecting lakes above ice is suffering from diverse image qualities and unexpected clouds. A new method is proposed to efficiently extract prominent lake candidates with irregular shapes, heterogeneous backgrounds, and in cloudy images. The proposed system fully automatize the procedure that track lakes with high accuracy. We further cooperated with geoscientists to examine the tracked lakes and found new scientific findings. The second one is detecting obscene content in on-line video chat services, such as Chatroulette, that randomly match pairs of users in video chat sessions. A big problem encountered in such systems is the presence of flashers and obscene content. Because of various obscene content and unstable qualities of videos capture by home web-camera, detecting misbehaving users is a highly challenging task. We propose SafeVchat, which is the first solution that achieves satisfactory

Dosimetric impact of image-guided 3D conformal radiation therapy of prostate cancer

International Nuclear Information System (INIS)

Schaly, B; Song, W; Bauman, G S; Battista, J J; Van Dyk, J

2005-01-01

The goal of this work is to quantify the impact of image-guided conformal radiation therapy (CRT) on the dose distribution by correcting patient setup uncertainty and inter-fraction tumour motion. This was a retrospective analysis that used five randomly selected prostate cancer patients that underwent approximately 15 computed tomography (CT) scans during their radiation treatment course. The beam arrangement from the treatment plan was imported into each repeat CT study and the dose distribution was recalculated for the new beam setups. Various setup scenarios were then compared to assess the impact of image guidance on radiation treatment precision. These included (1) daily alignment to skin markers, thus representing a conventional beam setup without image guidance (2) alignment to bony anatomy for correction of daily patient setup error, thus representing on-line portal image guidance, and (3) alignment to the 'CTV of the day' for correction of inter-fraction tumour motion, thus representing on-line CT or ultrasound image guidance. Treatment scenarios (1) and (3) were repeated with a reduced CTV to PTV margin, where the former represents a treatment using small margins without daily image guidance. Daily realignment of the treatment beams to the prostate showed an average increase in minimum tumour dose of 1.5 Gy, in all cases where tumour 'geographic miss' without image guidance was apparent. However, normal tissue sparing did not improve unless the PTV margin was reduced. Daily realignment to the tumour combined with reducing the margin size by a factor of 2 resulted in an average escalation in tumour dose of 9.0 Gy for all five static plans. However, the prescription dose could be escalated by 13.8 Gy when accounting for changes in anatomy by accumulating daily doses using nonlinear image registration techniques. These results provide quantitative information on the effectiveness of image-guided radiation treatment of prostate cancer and demonstrate that

Respiration-correlated image guidance is the most important radiotherapy motion management strategy for most lung cancer patients

DEFF Research Database (Denmark)

Korreman, Stine; Persson, Gitte; Nygaard, Ditte Eklund

2012-01-01

The purpose of this study was to quantify the effects of four-dimensional computed tomography (4DCT), 4D image guidance (4D-IG), and beam gating on calculated treatment field margins in a lung cancer patient population....

The development of a line-scan imaging algorithm for the detection of fecal contamination on leafy geens

Science.gov (United States)

Yang, Chun-Chieh; Kim, Moon S.; Chuang, Yung-Kun; Lee, Hoyoung

2013-05-01

This paper reports the development of a multispectral algorithm, using the line-scan hyperspectral imaging system, to detect fecal contamination on leafy greens. Fresh bovine feces were applied to the surfaces of washed loose baby spinach leaves. A hyperspectral line-scan imaging system was used to acquire hyperspectral fluorescence images of the contaminated leaves. Hyperspectral image analysis resulted in the selection of the 666 nm and 688 nm wavebands for a multispectral algorithm to rapidly detect feces on leafy greens, by use of the ratio of fluorescence intensities measured at those two wavebands (666 nm over 688 nm). The algorithm successfully distinguished most of the lowly diluted fecal spots (0.05 g feces/ml water and 0.025 g feces/ml water) and some of the highly diluted spots (0.0125 g feces/ml water and 0.00625 g feces/ml water) from the clean spinach leaves. The results showed the potential of the multispectral algorithm with line-scan imaging system for application to automated food processing lines for food safety inspection of leafy green vegetables.

An integrated on-line irradiation and in situ live cell imaging system

Energy Technology Data Exchange (ETDEWEB)

Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen, E-mail: gen.yang@pku.edu.cn; Wang, Yugang

2015-09-01

Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO{sub 2}, O{sub 2} concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia.

An integrated on-line irradiation and in situ live cell imaging system

International Nuclear Information System (INIS)

Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen; Wang, Yugang

2015-01-01

Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO 2 , O 2 concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia

An integrated on-line irradiation and in situ live cell imaging system

Science.gov (United States)

Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen; Wang, Yugang

2015-09-01

Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO2, O2 concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia.

Virtual Ultrasound Guidance for Inexperienced Operators

Science.gov (United States)

Caine, Timothy; Martin, David

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit in which the time delay inherent with communication will make remote guidance impractical. The Virtual Ultrasound Guidance system is a combination of hardware and software. The hardware portion includes, but is not limited to, video glasses that allow hands-free, full-screen viewing. The glasses also allow the operator a substantial field of view below the glasses to view and operate the ultrasound system. The software is a comprehensive video program designed to guide an inexperienced operator through a detailed ultrasound or echocardiographic study without extensive training or guidance from the ground. The program contains a detailed description using video and audio to demonstrate equipment controls, ergonomics of scanning, study protocol, and scanning guidance, including recovery from sub-optimal images. The components used in the initial validation of the system include an Apple iPod Classic third-generation as the video source, and Myvue video glasses. Initially, the program prompts the operator to power-up the ultrasound and position the patient. The operator would put on the video glasses and attach them to the video source. After turning on both devices and the ultrasound system, the audio-video guidance would then instruct on patient positioning and scanning techniques. A detailed scanning protocol follows with descriptions and reference video of each view along with

Planning, guidance, and quality assurance of pelvic screw placement using deformable image registration

Science.gov (United States)

Goerres, J.; Uneri, A.; Jacobson, M.; Ramsay, B.; De Silva, T.; Ketcha, M.; Han, R.; Manbachi, A.; Vogt, S.; Kleinszig, G.; Wolinsky, J.-P.; Osgood, G.; Siewerdsen, J. H.

2017-12-01

Percutaneous pelvic screw placement is challenging due to narrow bone corridors surrounded by vulnerable structures and difficult visual interpretation of complex anatomical shapes in 2D x-ray projection images. To address these challenges, a system for planning, guidance, and quality assurance (QA) is presented, providing functionality analogous to surgical navigation, but based on robust 3D-2D image registration techniques using fluoroscopy images already acquired in routine workflow. Two novel aspects of the system are investigated: automatic planning of pelvic screw trajectories and the ability to account for deformation of surgical devices (K-wire deflection). Atlas-based registration is used to calculate a patient-specific plan of screw trajectories in preoperative CT. 3D-2D registration aligns the patient to CT within the projective geometry of intraoperative fluoroscopy. Deformable known-component registration (dKC-Reg) localizes the surgical device, and the combination of plan and device location is used to provide guidance and QA. A leave-one-out analysis evaluated the accuracy of automatic planning, and a cadaver experiment compared the accuracy of dKC-Reg to rigid approaches (e.g. optical tracking). Surgical plans conformed within the bone cortex by 3-4 mm for the narrowest corridor (superior pubic ramus) and  >5 mm for the widest corridor (tear drop). The dKC-Reg algorithm localized the K-wire tip within 1.1 mm and 1.4° and was consistently more accurate than rigid-body tracking (errors up to 9 mm). The system was shown to automatically compute reliable screw trajectories and accurately localize deformed surgical devices (K-wires). Such capability could improve guidance and QA in orthopaedic surgery, where workflow is impeded by manual planning, conventional tool trackers add complexity and cost, rigid tool assumptions are often inaccurate, and qualitative interpretation of complex anatomy from 2D projections is prone to trial

On-line video image processing system for real-time neutron radiography

Energy Technology Data Exchange (ETDEWEB)

Fujine, S; Yoneda, K; Kanda, K [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

1983-09-15

The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 distinct colors on a RGB video display. The direct image of this system could be satisfactory for penetrating the side plates to test MTR type reactor fuels and for the investigation of moving objects.

Respiration-Correlated Image Guidance Is the Most Important Radiotherapy Motion Management Strategy for Most Lung Cancer Patients

International Nuclear Information System (INIS)

Korreman, Stine; Persson, Gitte; Nygaard, Ditte; Brink, Carsten; Juhler-Nøttrup, Trine

2012-01-01

Purpose: The purpose of this study was to quantify the effects of four-dimensional computed tomography (4DCT), 4D image guidance (4D-IG), and beam gating on calculated treatment field margins in a lung cancer patient population. Materials and Methods: Images were acquired from 46 lung cancer patients participating in four separate protocols at three institutions in Europe and the United States. Seven patients were imaged using fluoroscopy, and 39 patients were imaged using 4DCT. The magnitude of respiratory tumor motion was measured. The required treatment field margins were calculated using a statistical recipe (van Herk M, et al. Int J Radiat Oncol Biol Phys 2000;474:1121–1135), with magnitudes of all uncertainties, except respiratory peak-to-peak displacement, the same for all patients, taken from literature. Required margins for respiratory motion management were calculated using the residual respiratory tumor motion for each patient for various motion management strategies. Margin reductions for respiration management were calculated using 4DCT, 4D-IG, and gated beam delivery. Results: The median tumor motion magnitude was 4.4 mm for the 46 patients (range 0–29.3 mm). This value corresponded to required treatment field margins of 13.7 to 36.3 mm (median 14.4 mm). The use of 4DCT, 4D-IG, and beam gating required margins that were reduced by 0 to 13.9 mm (median 0.5 mm), 3 to 5.2 mm (median 5.1 mm), and 0 to 7 mm (median 0.2 mm), respectively, to a total of 8.5 to 12.4 mm (median 8.6 mm). Conclusion: A respiratory management strategy for lung cancer radiotherapy including planning on 4DCT scans and daily image guidance provides a potential reduction of 37% to 47% in treatment field margins. The 4D image guidance strategy was the most effective strategy for >85% of the patients.

Health Service use of ionising radiations: Guidance

International Nuclear Information System (INIS)

1995-01-01

This booklet gives outline guidance on the use of ionising radiations in the Health Service in the United Kingdom. Extensive reference is made to documents where more detailed information may be found. The guidance covers general advice on the medical use of ionising radiations, statutory requirements, and guidance on selected Health Service issues such as patient identification procedures, information management systems, deviations from prescribed radiation dose, imaging and radiotherapy. (57 references) (U.K.)

3D Power Line Extraction from Multiple Aerial Images

Directory of Open Access Journals (Sweden)

Jaehong Oh

2017-09-01

Full Text Available Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters.

LINE-BASED MULTI-IMAGE MATCHING FOR FAÇADE RECONSTRUCTION

Directory of Open Access Journals (Sweden)

T. A. Teo

2012-07-01

Full Text Available This research integrates existing LOD 2 building models and multiple close-range images for façade structural lines extraction. The major works are orientation determination and multiple image matching. In the orientation determination, Speeded Up Robust Features (SURF is applied to extract tie points automatically. Then, tie points and control points are combined for block adjustment. An object-based multi-images matching is proposed to extract the façade structural lines. The 2D lines in image space are extracted by Canny operator followed by Hough transform. The role of LOD 2 building models is to correct the tilt displacement of image from different views. The wall of LOD 2 model is also used to generate hypothesis planes for similarity measurement. Finally, average normalized cross correlation is calculated to obtain the best location in object space. The test images are acquired by a nonmetric camera Nikon D2X. The total number of image is 33. The experimental results indicate that the accuracy of orientation determination is about 1 pixel from 2515 tie points and 4 control points. It also indicates that line-based matching is more flexible than point-based matching.

SU-G-BRA-03: PCA Based Imaging Angle Optimization for 2D Cine MRI Based Radiotherapy Guidance

Energy Technology Data Exchange (ETDEWEB)

Chen, T; Yue, N; Jabbour, S; Zhang, M [Rutgers University, New Brunswick, NJ (United States)

2016-06-15

Purpose: To develop an imaging angle optimization methodology for orthogonal 2D cine MRI based radiotherapy guidance using Principal Component Analysis (PCA) of target motion retrieved from 4DCT. Methods: We retrospectively analyzed 4DCT of 6 patients with lung tumor. A radiation oncologist manually contoured the target volume at the maximal inhalation phase of the respiratory cycle. An object constrained deformable image registration (DIR) method has been developed to track the target motion along the respiration at ten phases. The motion of the center of the target mass has been analyzed using the PCA to find out the principal motion components that were uncorrelated with each other. Two orthogonal image planes for cineMRI have been determined using this method to minimize the through plane motion during MRI based radiotherapy guidance. Results: 3D target respiratory motion for all 6 patients has been efficiently retrieved from 4DCT. In this process, the object constrained DIR demonstrated satisfactory accuracy and efficiency to enable the automatic motion tracking for clinical application. The average motion amplitude in the AP, lateral, and longitudinal directions were 3.6mm (min: 1.6mm, max: 5.6mm), 1.7mm (min: 0.6mm, max: 2.7mm), and 5.6mm (min: 1.8mm, max: 16.1mm), respectively. Based on PCA, the optimal orthogonal imaging planes were determined for cineMRI. The average angular difference between the PCA determined imaging planes and the traditional AP and lateral imaging planes were 47 and 31 degrees, respectively. After optimization, the average amplitude of through plane motion reduced from 3.6mm in AP images to 2.5mm (min:1.3mm, max:3.9mm); and from 1.7mm in lateral images to 0.6mm (min: 0.2mm, max:1.5mm), while the principal in plane motion amplitude increased from 5.6mm to 6.5mm (min: 2.8mm, max: 17mm). Conclusion: DIR and PCA can be used to optimize the orthogonal image planes of cineMRI to minimize the through plane motion during radiotherapy

SU-G-BRA-03: PCA Based Imaging Angle Optimization for 2D Cine MRI Based Radiotherapy Guidance

International Nuclear Information System (INIS)

Chen, T; Yue, N; Jabbour, S; Zhang, M

2016-01-01

Purpose: To develop an imaging angle optimization methodology for orthogonal 2D cine MRI based radiotherapy guidance using Principal Component Analysis (PCA) of target motion retrieved from 4DCT. Methods: We retrospectively analyzed 4DCT of 6 patients with lung tumor. A radiation oncologist manually contoured the target volume at the maximal inhalation phase of the respiratory cycle. An object constrained deformable image registration (DIR) method has been developed to track the target motion along the respiration at ten phases. The motion of the center of the target mass has been analyzed using the PCA to find out the principal motion components that were uncorrelated with each other. Two orthogonal image planes for cineMRI have been determined using this method to minimize the through plane motion during MRI based radiotherapy guidance. Results: 3D target respiratory motion for all 6 patients has been efficiently retrieved from 4DCT. In this process, the object constrained DIR demonstrated satisfactory accuracy and efficiency to enable the automatic motion tracking for clinical application. The average motion amplitude in the AP, lateral, and longitudinal directions were 3.6mm (min: 1.6mm, max: 5.6mm), 1.7mm (min: 0.6mm, max: 2.7mm), and 5.6mm (min: 1.8mm, max: 16.1mm), respectively. Based on PCA, the optimal orthogonal imaging planes were determined for cineMRI. The average angular difference between the PCA determined imaging planes and the traditional AP and lateral imaging planes were 47 and 31 degrees, respectively. After optimization, the average amplitude of through plane motion reduced from 3.6mm in AP images to 2.5mm (min:1.3mm, max:3.9mm); and from 1.7mm in lateral images to 0.6mm (min: 0.2mm, max:1.5mm), while the principal in plane motion amplitude increased from 5.6mm to 6.5mm (min: 2.8mm, max: 17mm). Conclusion: DIR and PCA can be used to optimize the orthogonal image planes of cineMRI to minimize the through plane motion during radiotherapy

AUTOMATIC GLOBAL REGISTRATION BETWEEN AIRBORNE LIDAR DATA AND REMOTE SENSING IMAGE BASED ON STRAIGHT LINE FEATURES

Directory of Open Access Journals (Sweden)

Z. Q. Liu

2018-04-01

Full Text Available An automatic global registration approach for point clouds and remote sensing image based on straight line features is proposed which is insensitive to rotational and scale transformation. First, the building ridge lines and contour lines in point clouds are automatically detected as registration primitives by integrating region growth and topology identification. Second, the collinear condition equation is selected as registration transformation function which is based on rotation matrix described by unit quaternion. The similarity measure is established according to the distance between the corresponding straight line features from point clouds and the image in the same reference coordinate system. Finally, an iterative Hough transform is adopted to simultaneously estimate the parameters and obtain correspondence between registration primitives. Experimental results prove the proposed method is valid and the spectral information is useful for the following classification processing.

Supporting Development of Satellite's Guidance Navigation and Control Software: A Product Line Approach

Science.gov (United States)

McComas, David; Stark, Michael; Leake, Stephen; White, Michael; Morisio, Maurizio; Travassos, Guilherme H.; Powers, Edward I. (Technical Monitor)

2000-01-01

The NASA Goddard Space Flight Center Flight Software Branch (FSB) is developing a Guidance, Navigation, and Control (GNC) Flight Software (FSW) product line. The demand for increasingly more complex flight software in less time while maintaining the same level of quality has motivated us to look for better FSW development strategies. The GNC FSW product line has been planned to address the core GNC FSW functionality very similar on many recent low/near Earth missions in the last ten years. Unfortunately these missions have not accomplished significant drops in development cost since a systematic approach towards reuse has not been adopted. In addition, new demands are continually being placed upon the FSW which means the FSB must become more adept at providing GNC FSW functionality's core so it can accommodate additional requirements. These domain features together with engineering concepts are influencing the specification, description and evaluation of FSW product line. Domain engineering is the foundation for emerging product line software development approaches. A product line is 'A family of products designed to take advantage of their common aspects and predicted variabilities'. In our product line approach, domain engineering includes the engineering activities needed to produce reusable artifacts for a domain. Application engineering refers to developing an application in the domain starting from reusable artifacts. The focus of this paper is regarding the software process, lessons learned and on how the GNC FSW product line manages variability. Existing domain engineering approaches do not enforce any specific notation for domain analysis or commonality and variability analysis. Usually, natural language text is the preferred tool. The advantage is the flexibility and adapt ability of natural language. However, one has to be ready to accept also its well-known drawbacks, such as ambiguity, inconsistency, and contradictions. While most domain analysis

Review of research on sonar imaging technology in China

Science.gov (United States)

Guo, Haitao; Li, Renping; Xu, Feng; Liu, Liyuan

2013-11-01

Over the past 20 years, sonar imaging technology particularly for the high-technology sector has been a focus of research, in which many developed countries, especially those with coast lines, have been competing with each other. It has seen a rapid development with increasing widespread applications that has played an important and irreplaceable role in underwater exploration with great prospects for social, economic, scientific, and military benefits. The fundamental techniques underlying sonar imaging, including multi-beamforming, synthetic-aperture and inverse synthetic-aperture sonar, acoustic lensing, and acoustical holography, are described in this paper. This is followed by a comprehensive and systematic review on the advantages and disadvantages of these imaging techniques, applicability conditions, development trends, new ideas, new methods, and improvements in old methods over recent years with an emphasis on the situation in China, along with a bold and constructive prediction to some development characteristics of sonar imaging technology in the near future in China. The perspectives presented in this paper are offered with the idea of providing some degree of guidance and promotion of research on sonar imaging technology.

78 FR 12759 - Draft Guidance for Industry on Attachment to Guidance on Antiviral Product Development-Conducting...

Science.gov (United States)

2013-02-25

...; formerly 2005D-0183] Draft Guidance for Industry on Attachment to Guidance on Antiviral Product Development... guidance to the Division of Drug Information, Center for Drug Evaluation and Research, Food and Drug... 20852. FOR FURTHER INFORMATION CONTACT: Lisa K. Naeger, Center for Drug Evaluation and Research, Food...

Microscope self-calibration based on micro laser line imaging and soft computing algorithms

Science.gov (United States)

Apolinar Muñoz Rodríguez, J.

2018-06-01

A technique to perform microscope self-calibration via micro laser line and soft computing algorithms is presented. In this technique, the microscope vision parameters are computed by means of soft computing algorithms based on laser line projection. To implement the self-calibration, a microscope vision system is constructed by means of a CCD camera and a 38 μm laser line. From this arrangement, the microscope vision parameters are represented via Bezier approximation networks, which are accomplished through the laser line position. In this procedure, a genetic algorithm determines the microscope vision parameters by means of laser line imaging. Also, the approximation networks compute the three-dimensional vision by means of the laser line position. Additionally, the soft computing algorithms re-calibrate the vision parameters when the microscope vision system is modified during the vision task. The proposed self-calibration improves accuracy of the traditional microscope calibration, which is accomplished via external references to the microscope system. The capability of the self-calibration based on soft computing algorithms is determined by means of the calibration accuracy and the micro-scale measurement error. This contribution is corroborated by an evaluation based on the accuracy of the traditional microscope calibration.

On-line MR imaging for dose validation of abdominal radiotherapy

International Nuclear Information System (INIS)

Glitzner, M; Crijns, S P M; De Senneville, B Denis; Kontaxis, C; Prins, F M; Lagendijk, J J W; Raaymakers, B W

2015-01-01

For quality assurance and adaptive radiotherapy, validation of the actual delivered dose is crucial.Intrafractional anatomy changes cannot be captured satisfactorily during treatment with hitherto available imaging modalitites. Consequently, dose calculations are based on the assumption of static anatomy throughout the treatment. However, intra- and interfraction anatomy is dynamic and changes can be significant.In this paper, we investigate the use of an MR-linac as a dose tracking modality for the validation of treatments in abdominal targets where both respiratory and long-term peristaltic and drift motion occur.The on-line MR imaging capability of the modality provides the means to perform respiratory gating of both delivery and acquisition yielding a model-free respiratory motion management under free breathing conditions.In parallel to the treatment, the volumetric patient anatomy was captured and used to calculate the applied dose. Subsequently, the individual doses were warped back to the planning grid to obtain the actual dose accumulated over the entire treatment duration. Ultimately, the planned dose was validated by comparison with the accumulated dose.Representative for a site subject to breathing modulation, two kidney cases (25 Gy target dose) demonstrated the working principle on volunteer data and simulated delivery. The proposed workflow successfully showed its ability to track local dosimetric changes. Integration of the on-line anatomy information could reveal local dose variations  −2.3–1.5 Gy in the target volume of a volunteer dataset. In the adjacent organs at risk, high local dose errors ranging from  −2.5 to 1.9 Gy could be traced back. (paper)

On-line MR imaging for dose validation of abdominal radiotherapy

Science.gov (United States)

Glitzner, M.; Crijns, S. P. M.; de Senneville, B. Denis; Kontaxis, C.; Prins, F. M.; Lagendijk, J. J. W.; Raaymakers, B. W.

2015-11-01

For quality assurance and adaptive radiotherapy, validation of the actual delivered dose is crucial. Intrafractional anatomy changes cannot be captured satisfactorily during treatment with hitherto available imaging modalitites. Consequently, dose calculations are based on the assumption of static anatomy throughout the treatment. However, intra- and interfraction anatomy is dynamic and changes can be significant. In this paper, we investigate the use of an MR-linac as a dose tracking modality for the validation of treatments in abdominal targets where both respiratory and long-term peristaltic and drift motion occur. The on-line MR imaging capability of the modality provides the means to perform respiratory gating of both delivery and acquisition yielding a model-free respiratory motion management under free breathing conditions. In parallel to the treatment, the volumetric patient anatomy was captured and used to calculate the applied dose. Subsequently, the individual doses were warped back to the planning grid to obtain the actual dose accumulated over the entire treatment duration. Ultimately, the planned dose was validated by comparison with the accumulated dose. Representative for a site subject to breathing modulation, two kidney cases (25 Gy target dose) demonstrated the working principle on volunteer data and simulated delivery. The proposed workflow successfully showed its ability to track local dosimetric changes. Integration of the on-line anatomy information could reveal local dose variations  -2.3-1.5 Gy in the target volume of a volunteer dataset. In the adjacent organs at risk, high local dose errors ranging from  -2.5 to 1.9 Gy could be traced back.

Automated analysis of heterogeneous carbon nanostructures by high-resolution electron microscopy and on-line image processing

International Nuclear Information System (INIS)

Toth, P.; Farrer, J.K.; Palotas, A.B.; Lighty, J.S.; Eddings, E.G.

2013-01-01

High-resolution electron microscopy is an efficient tool for characterizing heterogeneous nanostructures; however, currently the analysis is a laborious and time-consuming manual process. In order to be able to accurately and robustly quantify heterostructures, one must obtain a statistically high number of micrographs showing images of the appropriate sub-structures. The second step of analysis is usually the application of digital image processing techniques in order to extract meaningful structural descriptors from the acquired images. In this paper it will be shown that by applying on-line image processing and basic machine vision algorithms, it is possible to fully automate the image acquisition step; therefore, the number of acquired images in a given time can be increased drastically without the need for additional human labor. The proposed automation technique works by computing fields of structural descriptors in situ and thus outputs sets of the desired structural descriptors in real-time. The merits of the method are demonstrated by using combustion-generated black carbon samples. - Highlights: ► The HRTEM analysis of heterogeneous nanostructures is a tedious manual process. ► Automatic HRTEM image acquisition and analysis can improve data quantity and quality. ► We propose a method based on on-line image analysis for the automation of HRTEM image acquisition. ► The proposed method is demonstrated using HRTEM images of soot particles

Image guidance doses delivered during radiotherapy: Quantification, management, and reduction: Report of the AAPM Therapy Physics Committee Task Group 180.

Science.gov (United States)

Ding, George X; Alaei, Parham; Curran, Bruce; Flynn, Ryan; Gossman, Michael; Mackie, T Rock; Miften, Moyed; Morin, Richard; Xu, X George; Zhu, Timothy C

2018-05-01

With radiotherapy having entered the era of image guidance, or image-guided radiation therapy (IGRT), imaging procedures are routinely performed for patient positioning and target localization. The imaging dose delivered may result in excessive dose to sensitive organs and potentially increase the chance of secondary cancers and, therefore, needs to be managed. This task group was charged with: a) providing an overview on imaging dose, including megavoltage electronic portal imaging (MV EPI), kilovoltage digital radiography (kV DR), Tomotherapy MV-CT, megavoltage cone-beam CT (MV-CBCT) and kilovoltage cone-beam CT (kV-CBCT), and b) providing general guidelines for commissioning dose calculation methods and managing imaging dose to patients. We briefly review the dose to radiotherapy (RT) patients resulting from different image guidance procedures and list typical organ doses resulting from MV and kV image acquisition procedures. We provide recommendations for managing the imaging dose, including different methods for its calculation, and techniques for reducing it. The recommended threshold beyond which imaging dose should be considered in the treatment planning process is 5% of the therapeutic target dose. Although the imaging dose resulting from current kV acquisition procedures is generally below this threshold, the ALARA principle should always be applied in practice. Medical physicists should make radiation oncologists aware of the imaging doses delivered to patients under their care. Balancing ALARA with the requirement for effective target localization requires that imaging dose be managed based on the consideration of weighing risks and benefits to the patient. © 2018 American Association of Physicists in Medicine.

Slots in dielectric image line as mode launchers and circuit elements

Science.gov (United States)

Solbach, K.

1981-01-01

A planar resonator model is used to investigate slots in the ground plane of dielectric image lines. An equivalent circuit representation of the slot discontinuity is obtained, and the launching efficiency of the slot as a mode launcher is analyzed. Slots are also shown to be useful in the realization of dielectric image line array antennas. It is found that the slot discontinuity can be shown as a T-junction of the dielectric image line and a metal waveguide. The launching efficiency is found to increase with the dielectric constant of the dielectric image line, exhibiting a maximum value for guides whose height is slightly less than half a wavelength in the dielectric medium. The measured launching efficiencies of low permittivity dielectric image lines are found to be in good agreement with calculated values

Fine Guidance Sensing for Coronagraphic Observatories

Science.gov (United States)

Brugarolas, Paul; Alexander, James W.; Trauger, John T.; Moody, Dwight C.

2011-01-01

Three options have been developed for Fine Guidance Sensing (FGS) for coronagraphic observatories using a Fine Guidance Camera within a coronagraphic instrument. Coronagraphic observatories require very fine precision pointing in order to image faint objects at very small distances from a target star. The Fine Guidance Camera measures the direction to the target star. The first option, referred to as Spot, was to collect all of the light reflected from a coronagraph occulter onto a focal plane, producing an Airy-type point spread function (PSF). This would allow almost all of the starlight from the central star to be used for centroiding. The second approach, referred to as Punctured Disk, collects the light that bypasses a central obscuration, producing a PSF with a punctured central disk. The final approach, referred to as Lyot, collects light after passing through the occulter at the Lyot stop. The study includes generation of representative images for each option by the science team, followed by an engineering evaluation of a centroiding or a photometric algorithm for each option. After the alignment of the coronagraph to the fine guidance system, a "nulling" point on the FGS focal point is determined by calibration. This alignment is implemented by a fine alignment mechanism that is part of the fine guidance camera selection mirror. If the star images meet the modeling assumptions, and the star "centroid" can be driven to that nulling point, the contrast for the coronagraph will be maximized.

MO-AB-BRA-02: A Novel Scatter Imaging Modality for Real-Time Image Guidance During Lung SBRT

International Nuclear Information System (INIS)

Redler, G; Bernard, D; Templeton, A; Chu, J; Nair, C Kumaran; Turian, J

2015-01-01

Purpose: A novel scatter imaging modality is developed and its feasibility for image-guided radiation therapy (IGRT) during stereotactic body radiation therapy (SBRT) for lung cancer patients is assessed using analytic and Monte Carlo models as well as experimental testing. Methods: During treatment, incident radiation interacts and scatters from within the patient. The presented methodology forms an image of patient anatomy from the scattered radiation for real-time localization of the treatment target. A radiographic flat panel-based pinhole camera provides spatial information regarding the origin of detected scattered radiation. An analytical model is developed, which provides a mathematical formalism for describing the scatter imaging system. Experimental scatter images are acquired by irradiating an object using a Varian TrueBeam accelerator. The differentiation between tissue types is investigated by imaging simple objects of known compositions (water, lung, and cortical bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is fabricated and imaged to investigate image quality for various quantities of delivered radiation. Monte Carlo N-Particle (MCNP) code is used for validation and testing by simulating scatter image formation using the experimental pinhole camera setup. Results: Analytical calculations, MCNP simulations, and experimental results when imaging the water, lung, and cortical bone equivalent objects show close agreement, thus validating the proposed models and demonstrating that scatter imaging differentiates these materials well. Lung tumor phantom images have sufficient contrast-to-noise ratio (CNR) to clearly distinguish tumor from surrounding lung tissue. CNR=4.1 and CNR=29.1 for 10MU and 5000MU images (equivalent to 0.5 and 250 second images), respectively. Conclusion: Lung SBRT provides favorable treatment outcomes, but depends on accurate target localization. A comprehensive

MO-AB-BRA-02: A Novel Scatter Imaging Modality for Real-Time Image Guidance During Lung SBRT

Energy Technology Data Exchange (ETDEWEB)

Redler, G; Bernard, D; Templeton, A; Chu, J [Rush University Medical Center, Chicago, IL (United States); Nair, C Kumaran [University of Chicago, Chicago, IL (United States); Turian, J [Rush University Medical Center, Chicago, IL (United States); Rush Radiosurgery LLC, Chicago, IL (United States)

2015-06-15

Purpose: A novel scatter imaging modality is developed and its feasibility for image-guided radiation therapy (IGRT) during stereotactic body radiation therapy (SBRT) for lung cancer patients is assessed using analytic and Monte Carlo models as well as experimental testing. Methods: During treatment, incident radiation interacts and scatters from within the patient. The presented methodology forms an image of patient anatomy from the scattered radiation for real-time localization of the treatment target. A radiographic flat panel-based pinhole camera provides spatial information regarding the origin of detected scattered radiation. An analytical model is developed, which provides a mathematical formalism for describing the scatter imaging system. Experimental scatter images are acquired by irradiating an object using a Varian TrueBeam accelerator. The differentiation between tissue types is investigated by imaging simple objects of known compositions (water, lung, and cortical bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is fabricated and imaged to investigate image quality for various quantities of delivered radiation. Monte Carlo N-Particle (MCNP) code is used for validation and testing by simulating scatter image formation using the experimental pinhole camera setup. Results: Analytical calculations, MCNP simulations, and experimental results when imaging the water, lung, and cortical bone equivalent objects show close agreement, thus validating the proposed models and demonstrating that scatter imaging differentiates these materials well. Lung tumor phantom images have sufficient contrast-to-noise ratio (CNR) to clearly distinguish tumor from surrounding lung tissue. CNR=4.1 and CNR=29.1 for 10MU and 5000MU images (equivalent to 0.5 and 250 second images), respectively. Conclusion: Lung SBRT provides favorable treatment outcomes, but depends on accurate target localization. A comprehensive

The Development of a Lifelong Guidance System in Hungary

Science.gov (United States)

Watts, A. G.; Borbely-Pecze, Bors Tibor

2011-01-01

The development of a lifelong guidance system in Hungary Systematic work is currently being undertaken in Hungary to develop a lifelong guidance system, in line with principles outlined by leading international organisations. The origins of career guidance in Hungary, and the nature of the current career guidance system, are outlined. The main…

WE-D-BRB-03: Current State of Volumetric Image Guidance for Proton Therapy

Energy Technology Data Exchange (ETDEWEB)

Hua, C. [St. Jude Children’s Research Hospital (United States)

2016-06-15

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. It introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.

WE-D-BRB-03: Current State of Volumetric Image Guidance for Proton Therapy

International Nuclear Information System (INIS)

Hua, C.

2016-01-01

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. It introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.

Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

Science.gov (United States)

Loehr, Johannes; Pfeiffer, Daniel; Schüler, Dirk; Fischer, Thomas M

2016-04-21

Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain.

Accuracy of cranial coplanar beam therapy using an oblique, stereoscopic x-ray image guidance system

International Nuclear Information System (INIS)

Vinci, Justin P.; Hogstrom, Kenneth R.; Neck, Daniel W.

2008-01-01

isocenter and radiation isocenter as documented by daily clinical Lutz tests. Based on results of comparisons of measured with calculated positions of the 80% dose lines along the major anatomical axes, a 1.25, 1.0, and 1.0 mm (0.75, 0.5, and 0.25 mm) gross tumor volume (GTV)-planning target volume (PTV) margin to account for delivery error would be appropriate for the P-A, R-L, and I-S axes, respectively, for an acceptance criteria of 1 mm/1 deg. (0.4 mm/0.4 deg. ). It typically took 2 (3) ExacTrac x-ray image sets to achieve and verify acceptance criteria of 1 mm/1 deg. (0.4 mm/0.4 deg. ). Our results demonstrated a measurement technique using a CIRS anthropomorphic head phantom with a modified film cassette, radiographic film (Kodak EDR2) with a custom film cutting template, and film dosimetry software has been developed and successfully applied to our clinic. It is recommended that a third party offer this service. Our goal of achieving accuracy of delivery of 1 mm or better in each of the three major anatomical axes was almost, but not quite achieved, not because of the accuracy of the image guidance system, but likely due to inaccuracy of laser isocenter and other systematic errors

A New Approach to Line Simplification Based on Image Processing: A Case Study of Water Area Boundaries

Directory of Open Access Journals (Sweden)

Yilang Shen

2018-01-01

Full Text Available Line simplification is an important component of map generalization. In recent years, algorithms for line simplification have been widely researched, and most of them are based on vector data. However, with the increasing development of computer vision, analysing and processing information from unstructured image data is both meaningful and challenging. Therefore, in this paper, we present a new line simplification approach based on image processing (BIP, which is specifically designed for raster data. First, the key corner points on a multi-scale image feature are detected and treated as candidate points. Then, to capture the essence of the shape within a given boundary using the fewest possible segments, the minimum-perimeter polygon (MPP is calculated and the points of the MPP are defined as the approximate feature points. Finally, the points after simplification are selected from the candidate points by comparing the distances between the candidate points and the approximate feature points. An empirical example was used to test the applicability of the proposed method. The results showed that (1 when the key corner points are detected based on a multi-scale image feature, the local features of the line can be extracted and retained and the positional accuracy of the proposed method can be maintained well; and (2 by defining the visibility constraint of geographical features, this method is especially suitable for simplifying water areas as it is aligned with people’s visual habits.

A concept to collect neutron and x-ray images on the same line of sight at NIF

Energy Technology Data Exchange (ETDEWEB)

Merrill, F. E., E-mail: fmerrill@lanl.gov; Danly, C. R.; Grim, G. P.; Volegov, P. L.; Wilde, C. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Izumi, N.; Jedlovec, D.; Fittinghoff, D. N.; Pak, A.; Park, H.-S. [Livermore National Laboratory, Livermore, California 94551 (United States)

2014-11-15

Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.

A concept to collect neutron and x-ray images on the same line of sight at NIF.

Science.gov (United States)

Merrill, F E; Danly, C R; Izumi, N; Jedlovec, D; Fittinghoff, D N; Grim, G P; Pak, A; Park, H-S; Volegov, P L; Wilde, C H

2014-11-01

Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.

Line-Scan Hyperspectral Imaging Techniques for Food Safety and Quality Applications

Directory of Open Access Journals (Sweden)

Jianwei Qin

2017-01-01

Full Text Available Hyperspectral imaging technologies in the food and agricultural area have been evolving rapidly over the past 15 years owing to tremendous interest from both academic and industrial fields. Line-scan hyperspectral imaging is a major method that has been intensively researched and developed using different physical principles (e.g., reflectance, transmittance, fluorescence, Raman, and spatially resolved spectroscopy and wavelength regions (e.g., visible (VIS, near infrared (NIR, and short-wavelength infrared (SWIR. Line-scan hyperspectral imaging systems are mainly developed and used for surface inspection of food and agricultural products using area or line light sources. Some of these systems can also be configured to conduct spatially resolved spectroscopy measurements for internal or subsurface food inspection using point light sources. This paper reviews line-scan hyperspectral imaging techniques, with introduction, demonstration, and summarization of existing and emerging techniques for food and agricultural applications. The main topics include related spectroscopy techniques, line-scan measurement methods, hardware components and systems, system calibration methods, and spectral and image analysis techniques. Applications in food safety and quality are also presented to reveal current practices and future trends of line-scan hyperspectral imaging techniques.

Detection of the power lines in UAV remote sensed images using spectral-spatial methods.

Science.gov (United States)

Bhola, Rishav; Krishna, Nandigam Hari; Ramesh, K N; Senthilnath, J; Anand, Gautham

2018-01-15

In this paper, detection of the power lines on images acquired by Unmanned Aerial Vehicle (UAV) based remote sensing is carried out using spectral-spatial methods. Spectral clustering was performed using Kmeans and Expectation Maximization (EM) algorithm to classify the pixels into the power lines and non-power lines. The spectral clustering methods used in this study are parametric in nature, to automate the number of clusters Davies-Bouldin index (DBI) is used. The UAV remote sensed image is clustered into the number of clusters determined by DBI. The k clustered image is merged into 2 clusters (power lines and non-power lines). Further, spatial segmentation was performed using morphological and geometric operations, to eliminate the non-power line regions. In this study, UAV images acquired at different altitudes and angles were analyzed to validate the robustness of the proposed method. It was observed that the EM with spatial segmentation (EM-Seg) performed better than the Kmeans with spatial segmentation (Kmeans-Seg) on most of the UAV images. Copyright © 2017 Elsevier Ltd. All rights reserved.

On- and off-line monitoring of ion beam treatment

Energy Technology Data Exchange (ETDEWEB)

Parodi, Katia, E-mail: katia.parodi@lmu.de

2016-02-11

Ion beam therapy is an emerging modality for high precision radiation treatment of cancer. In comparison to conventional radiation sources (photons, electrons), ion beams feature major dosimetric advantages due to their finite range with a localized dose deposition maximum, the Bragg peak, which can be selectively adjusted in depth. However, due to several sources of treatment uncertainties, full exploitation of these dosimetric advantages in clinical practice would require the possibility to visualize the stopping position of the ions in vivo, ideally in real-time. To this aim, different imaging methods have been proposed and investigated, either pre-clinically or even clinically, based on the detection of prompt or delayed radiation following nuclear interaction of the beam with the irradiated tissue. However, the chosen or ad-hoc developed instrumentation has often relied on technologies originally conceived for different applications, thus compromising on the achievable performances for the sake of cost-effectiveness. This contribution will review major examples of used instrumentation and related performances, identifying the most promising detector developments for next generation devices especially dedicated to on-line monitoring of ion beam treatment. Moreover, it will propose an original combination of different techniques in a hybrid detection scheme, aiming to make the most of complementary imaging methods and open new perspectives of image guidance for improved precision of ion beam therapy.

Snapshot imaging Fraunhofer line discriminator for detection of plant fluorescence

Science.gov (United States)

Gupta Roy, S.; Kudenov, M. W.

2015-05-01

Non-invasive quantification of plant health is traditionally accomplished using reflectance based metrics, such as the normalized difference vegetative index (NDVI). However, measuring plant fluorescence (both active and passive) to determine photochemistry of plants has gained importance. Due to better cost efficiency, lower power requirements, and simpler scanning synchronization, detecting passive fluorescence is preferred over active fluorescence. In this paper, we propose a high speed imaging approach for measuring passive plant fluorescence, within the hydrogen alpha Fraunhofer line at ~656 nm, using a Snapshot Imaging Fraunhofer Line Discriminator (SIFOLD). For the first time, the advantage of snapshot imaging for high throughput Fraunhofer Line Discrimination (FLD) is cultivated by our system, which is based on a multiple-image Fourier transform spectrometer and a spatial heterodyne interferometer (SHI). The SHI is a Sagnac interferometer, which is dispersion compensated using blazed diffraction gratings. We present data and techniques for calibrating the SIFOLD to any particular wavelength. This technique can be applied to quantify plant fluorescence at low cost and reduced complexity of data collection.

Evaluation of width and width uniformity of near-field electrospinning printed micro and sub-micrometer lines based on optical image processing

Science.gov (United States)

Zhao, Libo; Xia, Yong; Hebibul, Rahman; Wang, Jiuhong; Zhou, Xiangyang; Hu, Yingjie; Li, Zhikang; Luo, Guoxi; Zhao, Yulong; Jiang, Zhuangde

2018-03-01

This paper presents an experimental study using image processing to investigate width and width uniformity of sub-micrometer polyethylene oxide (PEO) lines fabricated by near-filed electrospinning (NFES) technique. An adaptive thresholding method was developed to determine the optimal gray values to accurately extract profiles of printed lines from original optical images. And it was proved with good feasibility. The mechanism of the proposed thresholding method was believed to take advantage of statistic property and get rid of halo induced errors. Triangular method and relative standard deviation (RSD) were introduced to calculate line width and width uniformity, respectively. Based on these image processing methods, the effects of process parameters including substrate speed (v), applied voltage (U), nozzle-to-collector distance (H), and syringe pump flow rate (Q) on width and width uniformity of printed lines were discussed. The research results are helpful to promote the NFES technique for fabricating high resolution micro and sub-micro lines and also helpful to optical image processing at sub-micro level.

Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions

International Nuclear Information System (INIS)

Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron

2010-01-01

Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 μm tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 μm, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154±113 μm. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions

Energy Technology Data Exchange (ETDEWEB)

Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron [Biomedical Engineering Graduate Program and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, Department of Surgery, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Electrical and Computer Engineering, Department of Medical Biophysics, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada)

2010-04-15

Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 {mu}m tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 {mu}m, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154{+-}113 {mu}m. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

ICRP guidance on radioactive waste disposal

International Nuclear Information System (INIS)

Cooper, J.R.

2002-01-01

The International Commission on Radiological Protection (ICRP) issued recommendations for a system of radiological protection in 1991 as the 1990 Recommendations. Guidance on the application of these recommendations in the general area of waste disposal was issued in 1997 as Publication 77 and guidance specific to disposal of solid long-lived radioactive waste was issued as Publication 81. This paper summarises ICRP guidance in radiological protection requirements for waste disposal concentrating on the ones of relevance to the geological disposal of solid radioactive waste. Suggestions are made for areas where further work is required to apply the ICRP guidance. (author)

Bezier-curve Navigation Guidance for Impact Time and Angle Control

Directory of Open Access Journals (Sweden)

Gun-Hee MOON

2018-03-01

Full Text Available This paper addresses a novel impact time and angle control guidance law using a Bézier curve. The 2nd order Bézier curve consists of one control point and two boundary points; initial point P0, middle point P1 and end point P2. The curve is tangent to the line P0-P1 and the line P1-P2, respectively, and always exists in the convex hull of the control points. Proposed Bézier curve navigation guidance, makes the missile follow the Bézier curve with the feedback form of guidance command so that the missile hits the target on the desired time in the desired direction. We conducted numerical simulations on several terminal conditions to demonstrate the performance of proposed method.

Improved Seam-Line Searching Algorithm for UAV Image Mosaic with Optical Flow.

Science.gov (United States)

Zhang, Weilong; Guo, Bingxuan; Li, Ming; Liao, Xuan; Li, Wenzhuo

2018-04-16

Ghosting and seams are two major challenges in creating unmanned aerial vehicle (UAV) image mosaic. In response to these problems, this paper proposes an improved method for UAV image seam-line searching. First, an image matching algorithm is used to extract and match the features of adjacent images, so that they can be transformed into the same coordinate system. Then, the gray scale difference, the gradient minimum, and the optical flow value of pixels in adjacent image overlapped area in a neighborhood are calculated, which can be applied to creating an energy function for seam-line searching. Based on that, an improved dynamic programming algorithm is proposed to search the optimal seam-lines to complete the UAV image mosaic. This algorithm adopts a more adaptive energy aggregation and traversal strategy, which can find a more ideal splicing path for adjacent UAV images and avoid the ground objects better. The experimental results show that the proposed method can effectively solve the problems of ghosting and seams in the panoramic UAV images.

Using Adobe Acrobat to create high-resolution line art images.

Science.gov (United States)

Woo, Hyoun Sik; Lee, Jeong Min

2009-08-01

The purpose of this article is to introduce a method for using Adobe Acrobat to make high-resolution and high-quality line art images. High-resolution and high-quality line art images for radiology journal submission can be generated using Adobe Acrobat as a steppingstone, and the customized PDF conversion settings can be used for converting hybrid images, including both bitmap and vector components.

Approach and landing guidance design for reusable launch vehicle using multiple sliding surfaces technique

Directory of Open Access Journals (Sweden)

Xiangdong LIU

2017-08-01

Full Text Available An autonomous approach and landing (A&L guidance law is presented in this paper for landing an unpowered reusable launch vehicle (RLV at the designated runway touchdown. Considering the full nonlinear point-mass dynamics, a guidance scheme is developed in three-dimensional space. In order to guarantee a successful A&L movement, the multiple sliding surfaces guidance (MSSG technique is applied to derive the closed-loop guidance law, which stems from higher order sliding mode control theory and has advantage in the finite time reaching property. The global stability of the proposed guidance approach is proved by the Lyapunov-based method. The designed guidance law can generate new trajectories on-line without any specific requirement on off-line analysis except for the information on the boundary conditions of the A&L phase and instantaneous states of the RLV. Therefore, the designed guidance law is flexible enough to target different touchdown points on the runway and is capable of dealing with large initial condition errors resulted from the previous flight phase. Finally, simulation results show the effectiveness of the proposed guidance law in different scenarios.

Magnetic imaging and machine vision NDT for the on-line inspection of stainless steel strips

International Nuclear Information System (INIS)

Ricci, M; Ficola, A; Fravolini, M L; Battaglini, L; Palazzi, A; Burrascano, P; Valigi, P; Appolloni, L; Cervo, S; Rocchi, C

2013-01-01

An on-line inspection system for stainless steel strips has been developed on an annealing and pickling line at the Acciai Speciali Terni S.p.A. steel mill. Besides a machine vision apparatus, the system contextually exploits a magnetic imaging system designed and realized for the specific application. The main goal of the research is represented by the fusion of the information provided by the two apparatuses that can improve the detection and classification tasks by enlarging the set of detectable defects. In this paper, the development, the calibration and the characteristics of the magnetic imaging apparatus are detailed and experimental results obtained both in laboratory and in situ are reported. A comparative analysis of the performances of the two devices is also reported based on preliminary results and some conclusions and perspectives are drawn. (paper)

New properties of the V-line Radon transform and their imaging applications

International Nuclear Information System (INIS)

Truong, T T; Nguyen, M K

2015-01-01

This paper reports on new aspects of the so-called V-line Radon transforms (RTs) complementing those reported in an earlier work. These new properties are nicely uncovered and described with Cartesian coordinates. In particular, we show that the V-line RT belongs to the class of RTs on curves in the plane which can be mapped onto the standard RT on straight lines and thereby are fully characterizable and invertible. Next, we show that the effect of geometric inversion on the V-line RT is to produce a new RT on a pair of supplementary circular arcs, which provides a new access to image reconstruction in the so-called Norton's modality of Compton scatter tomography, a front runner in the race for alternatives to current emission imaging. (paper)

TH-CD-207A-08: Simulated Real-Time Image Guidance for Lung SBRT Patients Using Scatter Imaging

International Nuclear Information System (INIS)

Redler, G; Cifter, G; Templeton, A; Lee, C; Bernard, D; Liao, Y; Zhen, H; Turian, J; Chu, J

2016-01-01

Purpose: To develop a comprehensive Monte Carlo-based model for the acquisition of scatter images of patient anatomy in real-time, during lung SBRT treatment. Methods: During SBRT treatment, images of patient anatomy can be acquired from scattered radiation. To rigorously examine the utility of scatter images for image guidance, a model is developed using MCNP code to simulate scatter images of phantoms and lung cancer patients. The model is validated by comparing experimental and simulated images of phantoms of different complexity. The differentiation between tissue types is investigated by imaging objects of known compositions (water, lung, and bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is used to investigate image noise properties for various quantities of delivered radiation (monitor units(MU)). Patient scatter images are simulated using the validated simulation model. 4DCT patient data is converted to an MCNP input geometry accounting for different tissue composition and densities. Lung tumor phantom images acquired with decreasing imaging time (decreasing MU) are used to model the expected noise amplitude in patient scatter images, producing realistic simulated patient scatter images with varying temporal resolution. Results: Image intensity in simulated and experimental scatter images of tissue equivalent objects (water, lung, bone) match within the uncertainty (∼3%). Lung tumor phantom images agree as well. Specifically, tumor-to-lung contrast matches within the uncertainty. The addition of random noise approximating quantum noise in experimental images to simulated patient images shows that scatter images of lung tumors can provide images in as fast as 0.5 seconds with CNR∼2.7. Conclusions: A scatter imaging simulation model is developed and validated using experimental phantom scatter images. Following validation, lung cancer patient scatter images are simulated. These simulated

TH-CD-207A-08: Simulated Real-Time Image Guidance for Lung SBRT Patients Using Scatter Imaging

Energy Technology Data Exchange (ETDEWEB)

Redler, G; Cifter, G; Templeton, A; Lee, C; Bernard, D; Liao, Y; Zhen, H; Turian, J; Chu, J [Rush University Medical Center, Chicago, IL (United States)

2016-06-15

Purpose: To develop a comprehensive Monte Carlo-based model for the acquisition of scatter images of patient anatomy in real-time, during lung SBRT treatment. Methods: During SBRT treatment, images of patient anatomy can be acquired from scattered radiation. To rigorously examine the utility of scatter images for image guidance, a model is developed using MCNP code to simulate scatter images of phantoms and lung cancer patients. The model is validated by comparing experimental and simulated images of phantoms of different complexity. The differentiation between tissue types is investigated by imaging objects of known compositions (water, lung, and bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is used to investigate image noise properties for various quantities of delivered radiation (monitor units(MU)). Patient scatter images are simulated using the validated simulation model. 4DCT patient data is converted to an MCNP input geometry accounting for different tissue composition and densities. Lung tumor phantom images acquired with decreasing imaging time (decreasing MU) are used to model the expected noise amplitude in patient scatter images, producing realistic simulated patient scatter images with varying temporal resolution. Results: Image intensity in simulated and experimental scatter images of tissue equivalent objects (water, lung, bone) match within the uncertainty (∼3%). Lung tumor phantom images agree as well. Specifically, tumor-to-lung contrast matches within the uncertainty. The addition of random noise approximating quantum noise in experimental images to simulated patient images shows that scatter images of lung tumors can provide images in as fast as 0.5 seconds with CNR∼2.7. Conclusions: A scatter imaging simulation model is developed and validated using experimental phantom scatter images. Following validation, lung cancer patient scatter images are simulated. These simulated

Image registration algorithm for high-voltage electric power live line working robot based on binocular vision

Science.gov (United States)

Li, Chengqi; Ren, Zhigang; Yang, Bo; An, Qinghao; Yu, Xiangru; Li, Jinping

2017-12-01

In the process of dismounting and assembling the drop switch for the high-voltage electric power live line working (EPL2W) robot, one of the key problems is the precision of positioning for manipulators, gripper and the bolts used to fix drop switch. To solve it, we study the binocular vision system theory of the robot and the characteristic of dismounting and assembling drop switch. We propose a coarse-to-fine image registration algorithm based on image correlation, which can improve the positioning precision of manipulators and bolt significantly. The algorithm performs the following three steps: firstly, the target points are marked respectively in the right and left visions, and then the system judges whether the target point in right vision can satisfy the lowest registration accuracy by using the similarity of target points' backgrounds in right and left visions, this is a typical coarse-to-fine strategy; secondly, the system calculates the epipolar line, and then the regional sequence existing matching points is generated according to neighborhood of epipolar line, the optimal matching image is confirmed by calculating the similarity between template image in left vision and the region in regional sequence according to correlation matching; finally, the precise coordinates of target points in right and left visions are calculated according to the optimal matching image. The experiment results indicate that the positioning accuracy of image coordinate is within 2 pixels, the positioning accuracy in the world coordinate system is within 3 mm, the positioning accuracy of binocular vision satisfies the requirement dismounting and assembling the drop switch.

Optimization and verification of image reconstruction for a Compton camera towards application as an on-line monitor for particle therapy

Science.gov (United States)

Taya, T.; Kataoka, J.; Kishimoto, A.; Tagawa, L.; Mochizuki, S.; Toshito, T.; Kimura, M.; Nagao, Y.; Kurita, K.; Yamaguchi, M.; Kawachi, N.

2017-07-01

Particle therapy is an advanced cancer therapy that uses a feature known as the Bragg peak, in which particle beams suddenly lose their energy near the end of their range. The Bragg peak enables particle beams to damage tumors effectively. To achieve precise therapy, the demand for accurate and quantitative imaging of the beam irradiation region or dosage during therapy has increased. The most common method of particle range verification is imaging of annihilation gamma rays by positron emission tomography. Not only 511-keV gamma rays but also prompt gamma rays are generated during therapy; therefore, the Compton camera is expected to be used as an on-line monitor for particle therapy, as it can image these gamma rays in real time. Proton therapy, one of the most common particle therapies, uses a proton beam of approximately 200 MeV, which has a range of ~ 25 cm in water. As gamma rays are emitted along the path of the proton beam, quantitative evaluation of the reconstructed images of diffuse sources becomes crucial, but it is far from being fully developed for Compton camera imaging at present. In this study, we first quantitatively evaluated reconstructed Compton camera images of uniformly distributed diffuse sources, and then confirmed that our Compton camera obtained 3 %(1 σ) and 5 %(1 σ) uniformity for line and plane sources, respectively. Based on this quantitative study, we demonstrated on-line gamma imaging during proton irradiation. Through these studies, we show that the Compton camera is suitable for future use as an on-line monitor for particle therapy.

Advanced approach for intraoperative MRI guidance and potential benefit for neurosurgical applications.

Science.gov (United States)

Busse, Harald; Schmitgen, Arno; Trantakis, Christos; Schober, Ralf; Kahn, Thomas; Moche, Michael

2006-07-01

To present an advanced approach for intraoperative image guidance in an open 0.5 T MRI and to evaluate its effectiveness for neurosurgical interventions by comparison with a dynamic scan-guided localization technique. The built-in scan guidance mode relied on successive interactive MRI scans. The additional advanced mode provided real-time navigation based on reformatted high-quality, intraoperatively acquired MR reference data, allowed multimodal image fusion, and used the successive scans of the built-in mode for quick verification of the position only. Analysis involved tumor resections and biopsies in either scan guidance (N = 36) or advanced mode (N = 59) by the same three neurosurgeons. Technical, surgical, and workflow aspects were compared. The image quality and hand-eye coordination of the advanced approach were improved. While the average extent of resection, neurologic outcome after functional MRI (fMRI) integration, and diagnostic yield appeared to be slightly better under advanced guidance, particularly for the main surgeon, statistical analysis revealed no significant differences. Resection times were comparable, while biopsies took around 30 minutes longer. The presented approach is safe and provides more detailed images and higher navigation speed at the expense of actuality. The surgical outcome achieved with advanced guidance is (at least) as good as that obtained with dynamic scan guidance. (c) 2006 Wiley-Liss, Inc.

Real-time CT-video registration for continuous endoscopic guidance

Science.gov (United States)

Merritt, Scott A.; Rai, Lav; Higgins, William E.

2006-03-01

Previous research has shown that CT-image-based guidance could be useful for the bronchoscopic assessment of lung cancer. This research drew upon the registration of bronchoscopic video images to CT-based endoluminal renderings of the airway tree. The proposed methods either were restricted to discrete single-frame registration, which took several seconds to complete, or required non-real-time buffering and processing of video sequences. We have devised a fast 2D/3D image registration method that performs single-frame CT-Video registration in under 1/15th of a second. This allows the method to be used for real-time registration at full video frame rates without significantly altering the physician's behavior. The method achieves its speed through a gradient-based optimization method that allows most of the computation to be performed off-line. During live registration, the optimization iteratively steps toward the locally optimal viewpoint at which a CT-based endoluminal view is most similar to a current bronchoscopic video frame. After an initial registration to begin the process (generally done in the trachea for bronchoscopy), subsequent registrations are performed in real-time on each incoming video frame. As each new bronchoscopic video frame becomes available, the current optimization is initialized using the previous frame's optimization result, allowing continuous guidance to proceed without manual re-initialization. Tests were performed using both synthetic and pre-recorded bronchoscopic video. The results show that the method is robust to initialization errors, that registration accuracy is high, and that continuous registration can proceed on real-time video at >15 frames per sec. with minimal user-intervention.

Image of a line is not shrunk but neglected. Absence of crossover in unilateral spatial neglect.

Science.gov (United States)

Ishiai, Sumio; Koyama, Yasumasa; Nakano, Naomi; Seki, Keiko; Nishida, Yoichiro; Hayashi, Kazuko

2004-01-01

Patients with left unilateral spatial neglect following right hemisphere lesions usually err rightward when bisecting a horizontal line. For very short lines (e.g. 25 mm), however, leftward errors or seemingly 'right' neglect is often observed. To explain this paradox of crossover in the direction of errors, rather complicated models have been introduced as to the distribution of attention. Neglect may be hypothesized to occur in representational process of a line or estimation of the midpoint on the formed image, or both. We devised a line image task using a computer display with a touch panel and approached the representational image of a line to be bisected. Three patients with typical left neglect were presented with a line and forced to see its whole extent with cueing to the left endpoint. After disappearance of the line, they pointed to the right endpoint, the left endpoint, or the subjective midpoint according to their representational image. The line image between the reproduced right and left endpoints was appropriately formed for the 200 mm lines. However, the images for the shorter 25 and 100 mm lines were longer than the physical lengths with overextension to the left side. These results proved the context effect that short lines may be perceived longer when they are presented in combination with longer lines. One of our patients had an extensive lesion that involved the frontal, temporal, and parietal lobes, and the other two had a lesion restricted to the posterior right hemisphere. The image for a fully perceived line may be represented far enough into left space even when left neglect occurs after a lesion that involves the right parietal lobe. The patients with neglect placed the subjective midpoint rightward from the centre of the stimulus line for the 100 and 200 mm lines and leftward for the 25 mm lines. This crossover of bisection errors disappeared when the displacement of the subjective midpoint was measured from the centre of the

The effect of sidewall roughness on line edge roughness in top-down scanning electron microscopy images

Science.gov (United States)

Verduin, T.; Lokhorst, S. R.; Kruit, P.; Hagen, C. W.

2015-03-01

We have investigated in a numerical study the determination of sidewall roughness (SWR) from top down scanning electron microscopy (SEM) images. In a typical metrology application, top-down SEM images are acquired in a (critical-dimension) SEM and the roughness is analyzed. However, the true size, shape and roughness characteristics of resist features are not fully investigated in the analysis of top-down SEM images. In reality, rough resist features are complex three-dimensional structures and the characterization naturally extends to the analysis of SWR. In this study we randomly generate images of rough lines and spaces, where the lines are made of PMMA on a silicon substrate. The lines that we study have a length of 2 µm, a width of 32nm and a height of 32 nm. The SWR is modeled by using the power spectral density (PSD) function of Palasantzas, which characterizes roughness by the standard deviation σ, correlation length ξ and roughness exponent α . The actual roughness is generated by application of the method of Thorsos in two dimensions. The images are constructed by using a home-built program for simulating electron-specimen interactions. The program that we have developed is optimized for complex arbitrary geometries and large number of incident low energy primary electrons by using multi-core CPUs and GPUs. The program uses the dielectric function model for inelastic scattering events and has an implementation specifically for low energy electrons. A satisfactory comparison is made between the secondary electron yields from the home-built program and another program found in literature. In order to reduce the risk of shrinkage, we use a beam energy of 300 eV and a spot size of 3 nm. Each pixel is exposed with 20 electrons on average (≍ 276 µC/cm2), following the Poisson distribution to account for illumination shot noise. We have assumed that the detection of electrons is perfect and does not introduce additional noise. We measure line edge

Laparoscopic Heller Myotomy for Non-Dilated Esophageal Achalasia in Children with Intraoperative Stepped Dilation Under Image Guidance: Attempting Complete Myotomy.

Science.gov (United States)

Miyano, Go; Miyake, Hiromu; Koyama, Mariko; Morita, Keiichi; Kaneshiro, Masakatsu; Nouso, Hiroshi; Yamoto, Masaya; Fukumoto, Koji; Urushihara, Naoto

2016-05-01

This study presents a modified surgical approach to laparoscopic myotomy for achalasia using stepped dilation with a Rigiflex balloon and contrast medium under image guidance. A 10-year-old boy with persistent dysphagia and vomiting had ingested only liquids for 3 months, losing >10 kg in body weight. Barium swallow and esophageal manometry diagnosed esophageal achalasia with mild esophageal dilatation. After failed pneumatic dilatation, laparoscopic Heller myotomy with Dor fundoplication was performed. Prior to surgery, a Rigiflex balloon dilator was placed within the esophagus near the diaphragmatic hiatus. A four-port technique was used, and mobilization of the esophagus was limited to the anterior aspect. A 5-cm Heller myotomy was performed, extending another 2 cm onto the anterior gastric wall. During myotomy, the Rigiflex balloon was serially dilated from 30 to 50 mL, and filled with contrast medium under fluoroscopic image guidance in order to maintain appropriate tension on the esophagus to facilitate myotomy, and to confirm adequate myotomy with sufficient release of lower esophageal sphincter by resecting residual circular muscle fibers. Residual circular muscle fibers can be simultaneously visualized under both fluoroscopic image guidance and direct observation through the laparoscope, and they were cut precisely until the residual notch fully disappeared. Dor fundoplication was completed. The operative time was 180 minutes, and oral intake was started after esophagography on postoperative day 1. As of the 12-month follow-up, the patient has not shown any symptoms, and his postoperative course appeared satisfactory.

SU-D-BRF-05: A Novel System to Provide Real-Time Image-Guidance for Intrauterine Tandem Insertion and Placement

Energy Technology Data Exchange (ETDEWEB)

Price, M; Fontenot, J [pF Biomedical Solutions LLC, Baton Rouge, LA (United States)

2014-06-01

Purpose: To develop a system that provides real-time image-guidance for intrauterine tandem insertion and placement for brachytherapy. Methods: The conceptualized system consists of an intrauterine tandem with a transparent, lensed tip, a flexible miniature fiber optic scope, light source and interface for CCD coupling. The tandem tip was designed to act as a lens providing a wide field-of-view (FOV) with minimal image distortion and focus length appropriate for the application. The system is designed so that once inserted, the image-guidance component of the system can be removed and brachytherapy can be administered without interfering with source transport or disturbing tandem placement. Proof-of-principle studies were conducted to assess the conceptualized system's (1) lens functionality (clarity, focus and FOV) (2) and ability to visualize the cervical os of a female placed in the lithotomy position. Results: A prototype of this device was constructed using a commercial tandem modified to incorporate a transparent tip that internally coupled with a 1.9mm diameter fiber optic cable. The 900mm-long cable terminated at an interface that provided illumination as well as facilitated visualization of patient anatomy on a computer. The system provided a 23mm FOV with a focal length of 1cm and provided clear visualization of the cervix, cervical fornix and cervical os. The optical components of the system are easily removed without perturbing the position of a tandem placed in a common fixation clamp. Conclusion: Clinicians frequently encounter difficulty inserting an intrauterine tandem through the cervical os, circumventing fibrotic tissue or masses within the uterus, and positioning the tandem without perforating the uterus. To mitigate these challenges, we have designed and conducted proof-of- principle studies to discern the utility of a prototype device that provides real-time image-guidance for intrauterine tandem placement using fiber optic components.

Numerical design of in-line X-ray phase-contrast imaging based on ellipsoidal single-bounce monocapillary

Energy Technology Data Exchange (ETDEWEB)

Sun, Weiyuan; Liu, Zhiguo [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi, E-mail: stx@bnu.edu.cn [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Peng, Song [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Ma, Yongzhong [Center for Disease Control and Prevention of Beijing, Beijing 100013 (China); Ding, Xunliang [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

2014-05-11

A new device using an ellipsoidal single-bounce monocapillary X-ray optics was numerically designed to realize in-line X-ray phase-contrast imaging by using conventional laboratory X-ray source with a large spot. Numerical simulation results validated the effectiveness of the proposed device and approach. The ellipsoidal single-bounce monocapillary X-ray optics had potential applications in the in-line phase contrast imaging with polychromatic X-rays.

Numerical design of in-line X-ray phase-contrast imaging based on ellipsoidal single-bounce monocapillary

International Nuclear Information System (INIS)

Sun, Weiyuan; Liu, Zhiguo; Sun, Tianxi; Peng, Song; Ma, Yongzhong; Ding, Xunliang

2014-01-01

A new device using an ellipsoidal single-bounce monocapillary X-ray optics was numerically designed to realize in-line X-ray phase-contrast imaging by using conventional laboratory X-ray source with a large spot. Numerical simulation results validated the effectiveness of the proposed device and approach. The ellipsoidal single-bounce monocapillary X-ray optics had potential applications in the in-line phase contrast imaging with polychromatic X-rays

Design, development, and evaluation of an automatic guidance system for tractor tracking along the contour line on inclined surfaces

Directory of Open Access Journals (Sweden)

S Dehghani

2016-04-01

Full Text Available Introduction: Automatic guidance of tractors in the mechanized farming practice has taken the attention of agricultural engineers in the last two decades. For this to be truly practical on the farm, it should be economical, simple to operate and entirely contained on the vehicle. Different types of steering systems such as leader- cable, laser- controlled, radio- operated and contactor- type have been developed for automatic guidance. The automatic leveling system is used on hillside machines to keep the separator level when operating on hillsides. This system has three parts: fluid level system, electrical system and hydraulic system. The fluid level system consists of fluid reservoir and a leveling control switch box. The fluid level system actuates the electrical system of the leveling unit. The electrical system which actuated by the fluid system consist of four micro switches in the leveling control switch box, two micro switches in the limit control box, a solenoid in the hydraulic control level, manual leveling control switch, and a leveling limit warning light. The hydraulic system maintains the level of the separator when the machine is operating on a hillside. The present study was aimed to develop a reliable, versatile and easy to maintain system to fit our economy and low technology level of farmers for hillside- range development or fallow farming. The automatic guidance system has been implemented successfully on agricultural vehicles on the basis of three components, i.e. sensors, processors and actuator elements. The study site (N, latitude; E, longitude; and 1810 m above sea level was located at the Agricultural Research Center, Shiraz University, 15 km northwest of Shiraz, Fars Province, Iran. MF-399 agricultural tractor manufactured by ITMCO, Tabriz, Iran was used for doing the experiments. Materials and Methods:The Level Sensing System: The biaxial tilt industrial sensor (ZCT245AL- China with digital output can be connected

Optimization of Proton CT Detector System and Image Reconstruction Algorithm for On-Line Proton Therapy.

Directory of Open Access Journals (Sweden)

Chae Young Lee

Full Text Available The purposes of this study were to optimize a proton computed tomography system (pCT for proton range verification and to confirm the pCT image reconstruction algorithm based on projection images generated with optimized parameters. For this purpose, we developed a new pCT scanner using the Geometry and Tracking (GEANT 4.9.6 simulation toolkit. GEANT4 simulations were performed to optimize the geometric parameters representing the detector thickness and the distance between the detectors for pCT. The system consisted of four silicon strip detectors for particle tracking and a calorimeter to measure the residual energies of the individual protons. The optimized pCT system design was then adjusted to ensure that the solution to a CS-based convex optimization problem would converge to yield the desired pCT images after a reasonable number of iterative corrections. In particular, we used a total variation-based formulation that has been useful in exploiting prior knowledge about the minimal variations of proton attenuation characteristics in the human body. Examinations performed using our CS algorithm showed that high-quality pCT images could be reconstructed using sets of 72 projections within 20 iterations and without any streaks or noise, which can be caused by under-sampling and proton starvation. Moreover, the images yielded by this CS algorithm were found to be of higher quality than those obtained using other reconstruction algorithms. The optimized pCT scanner system demonstrated the potential to perform high-quality pCT during on-line image-guided proton therapy, without increasing the imaging dose, by applying our CS based proton CT reconstruction algorithm. Further, we make our optimized detector system and CS-based proton CT reconstruction algorithm potentially useful in on-line proton therapy.

Volume of interest CBCT and tube current modulation for image guidance using dynamic kV collimation

Energy Technology Data Exchange (ETDEWEB)

Parsons, David, E-mail: david.parsons@dal.ca, E-mail: james.robar@nshealth.ca [Department of Physics and Atmospheric Science, Dalhousie University, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada); Robar, James L., E-mail: david.parsons@dal.ca, E-mail: james.robar@nshealth.ca [Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada)

2016-04-15

Purpose: The focus of this work is the development of a novel blade collimation system enabling volume of interest (VOI) CBCT with tube current modulation using the kV image guidance source on a linear accelerator. Advantages of the system are assessed, particularly with regard to reduction and localization of dose and improvement of image quality. Methods: A four blade dynamic kV collimator was developed to track a VOI during a CBCT acquisition. The current prototype is capable of tracking an arbitrary volume defined by the treatment planner for subsequent CBCT guidance. During gantry rotation, the collimator tracks the VOI with adjustment of position and dimension. CBCT image quality was investigated as a function of collimator dimension, while maintaining the same dose to the VOI, for a 22.2 cm diameter cylindrical water phantom with a 9 mm diameter bone insert centered on isocenter. Dose distributions were modeled using a dynamic BEAMnrc library and DOSXYZnrc. The resulting VOI dose distributions were compared to full-field CBCT distributions to quantify dose reduction and localization to the target volume. A novel method of optimizing x-ray tube current during CBCT acquisition was developed and assessed with regard to contrast-to-noise ratio (CNR) and imaging dose. Results: Measurements show that the VOI CBCT method using the dynamic blade system yields an increase in contrast-to-noise ratio by a factor of approximately 2.2. Depending upon the anatomical site, dose was reduced to 15%–80% of the full-field CBCT value along the central axis plane and down to less than 1% out of plane. The use of tube current modulation allowed for specification of a desired SNR within projection data. For approximately the same dose to the VOI, CNR was further increased by a factor of 1.2 for modulated VOI CBCT, giving a combined improvement of 2.6 compared to full-field CBCT. Conclusions: The present dynamic blade system provides significant improvements in CNR for the same

Combined echo offset (Dixon) and line volume chemical shift imaging as a clinical imaging protocol

International Nuclear Information System (INIS)

Listerud, J.; Chan, T.; Lenkinski, R.E.; Kressel, H.Y.; Chao, P.W.

1989-01-01

The authors have studied the sensitivity and specificity of the line-volume chemical-shift imaging (CSI) method as compared with the Dixon method they have recently implemented on a Signa, which supports a variety of options. Potential sources or error for the Dixon method include line broadening due to susceptibility, field inhomogeneity, and errors form olefinic resonances associated with fat, which behave like water in the Dixon regime. The authors investigate whether a combined Dixon/line-volume CSI method could be used to improve the placement of the line volume and to provide higher sensitivity and specificity than does the Dixon method alone

Spacecraft intercept guidance using zero effort miss steering

Science.gov (United States)

Newman, Brett

The suitability of proportional navigation, or an equivalent zero effort miss formulation, for spacecraft intercepts during midcourse guidance, followed by a ballistic coast to the endgame, is addressed. The problem is formulated in terms of relative motion in a general 3D framework. The proposed guidance law for the commanded thrust vector orientation consists of the sum of two terms: (1) along the line of sight unit direction and (2) along the zero effort miss component perpendicular to the line of sight and proportional to the miss itself and a guidance gain. If the guidance law is to be suitable for longer range targeting applications with significant ballistic coasting after burnout, determination of the zero effort miss must account for the different gravitational accelerations experienced by each vehicle. The proposed miss determination techniques employ approximations for the true differential gravity effect. Theoretical results are applied to a numerical engagement scenario and the resulting performance is evaluated in terms of the miss distances determined from nonlinear simulation.

NMR imaging of solids with multiple-pulse line narrowing and radiofrequency gradients

International Nuclear Information System (INIS)

Werner, M.H.

1993-01-01

The usual methods of magnetic resonance imaging fail in rigid solids due to the line-shape contributions of dipolar coupling, chemical shift dispersion and anisotropy, and bulk magnetic susceptibility. This dissertation presents a new method of solid-stage imaging by nuclear magnetic resonance which averages away these contributions with multiple-pulse line-narrowing and encodes spatial information with pulsed radiofrequency field gradients. This method is closely related to simultaneously developed methods utilizing pulsed DC gradients, and offers similar improvements in sensitivity and resolution. The advantage of rf gradients is that they can be rapidly switched without inducing eddy currents in the probe or the magnet. In addition, the phases and amplitudes of the rf gradients can be switched by equipment which is already part of an NMR spectrometer capable of solid-state spectroscopy. The line-narrowing and gradient pulses originate in separate rf circuits tuned to the same frequency. Interactions between the circuits have been minimized by a method of active Q-switching which employs PIN diodes in the matching networks of these circuits. Both one- and two-dimensional images are presented. The latter are obtained by a novel method in which the two dimensions of imaging transverse to the static magnetic field are encoded by two orthogonal components of a single rf gradient. A π/2 phase shift of the rf phase relative to that of the line-narrowing pulses selects one component or the other. This arrangement allows the solid-state analogs of versatile imaging sequences based on Fourier imaging and eliminates the need for sample rotation and back-projection methods. Coherent averaging theory is used to analyze this imaging technique and exact numerical simulations on several coupled spins are discussed. These lend insight to the residual linewidth and its dependence on pixel position as well as to the range of applicability of this technique

Integrated CLOS and PN Guidance for Increased Effectiveness of Surface to Air Missiles

Directory of Open Access Journals (Sweden)

Binte Fatima Tuz ZAHRA

2017-06-01

Full Text Available In this paper, a novel approach has been presented to integrate command to line-of-sight (CLOS guidance and proportional navigation (PN guidance in order to reduce miss distance and to increase the effectiveness of surface to air missiles. Initially a comparison of command to line-of-sight guidance and proportional navigation has been presented. Miss distance, variation of angle-of-attack, normal and lateral accelerations and error of missile flight path from direct line-of-sight have been used as noteworthy criteria for comparison of the two guidance laws. Following this comparison a new approach has been proposed for determining the most suitable guidance gains in order to minimize miss distance and improve accuracy of the missile in delivering the warhead, while using CLOS guidance. This proposed technique is based on constrained nonlinear minimization to optimize the guidance gains. CLOS guidance has a further limitation of significant increase in normal and lateral acceleration demands during the terminal phase of missile flight. Furthermore, at large elevation angles, the required angle-of-attack during the terminal phase increases beyond design specifications. Subsequently, a missile with optical sensors only and following just the CLOS guidance has less likelihood to hit high speed targets beyond 45º in elevation plane. A novel approach has thus been proposed to overcome such limitations of CLOS-only guidance for surface to air missiles. In this approach, an integrated guidance algorithm has been proposed whereby the initial guidance law during rocket motor burnout phase remains CLOS, whereas immediately after this phase, the guidance law is automatically switched to PN guidance. This integrated approach has not only resulted in slight increase in range of the missile but also has significantly improved its likelihood to hit targets beyond 30 degrees in elevation plane, thus successfully overcoming various limitations of CLOS

Use of a line-pair resolution phantom for comprehensive quality assurance of electronic portal imaging devices based on fundamental imaging metrics

International Nuclear Information System (INIS)

Gopal, Arun; Samant, Sanjiv S.

2009-01-01

Image guided radiation therapy solutions based on megavoltage computed tomography (MVCT) involve the extension of electronic portal imaging devices (EPIDs) from their traditional role of weekly localization imaging and planar dose mapping to volumetric imaging for 3D setup and dose verification. To sustain the potential advantages of MVCT, EPIDs are required to provide improved levels of portal image quality. Therefore, it is vital that the performance of EPIDs in clinical use is maintained at an optimal level through regular and rigorous quality assurance (QA). Traditionally, portal imaging QA has been carried out by imaging calibrated line-pair and contrast resolution phantoms and obtaining arbitrarily defined QA indices that are usually dependent on imaging conditions and merely indicate relative trends in imaging performance. They are not adequately sensitive to all aspects of image quality unlike fundamental imaging metrics such as the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) that are widely used to characterize detector performance in radiographic imaging and would be ideal for QA purposes. However, due to the difficulty of performing conventional MTF measurements, they have not been used for routine clinical QA. The authors present a simple and quick QA methodology based on obtaining the MTF, NPS, and DQE of a megavoltage imager by imaging standard open fields and a bar-pattern QA phantom containing 2 mm thick tungsten line-pair bar resolution targets. Our bar-pattern based MTF measurement features a novel zero-frequency normalization scheme that eliminates normalization errors typically associated with traditional bar-pattern measurements at megavoltage x-ray energies. The bar-pattern QA phantom and open-field images are used in conjunction with an automated image analysis algorithm that quickly computes the MTF, NPS, and DQE of an EPID system. Our approach combines the fundamental advantages of

Physics-based shape matching for intraoperative image guidance

Energy Technology Data Exchange (ETDEWEB)

Suwelack, Stefan, E-mail: suwelack@kit.edu; Röhl, Sebastian; Bodenstedt, Sebastian; Reichard, Daniel; Dillmann, Rüdiger; Speidel, Stefanie [Institute for Anthropomatics and Robotics, Karlsruhe Institute of Technology, Adenauerring 2, Karlsruhe 76131 (Germany); Santos, Thiago dos; Maier-Hein, Lena [Computer-assisted Interventions, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg 69120 (Germany); Wagner, Martin; Wünscher, Josephine; Kenngott, Hannes; Müller, Beat P. [General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Im Neuenheimer Feld 110, Heidelberg 69120 (Germany)

2014-11-01

Purpose: Soft-tissue deformations can severely degrade the validity of preoperative planning data during computer assisted interventions. Intraoperative imaging such as stereo endoscopic, time-of-flight or, laser range scanner data can be used to compensate these movements. In this context, the intraoperative surface has to be matched to the preoperative model. The shape matching is especially challenging in the intraoperative setting due to noisy sensor data, only partially visible surfaces, ambiguous shape descriptors, and real-time requirements. Methods: A novel physics-based shape matching (PBSM) approach to register intraoperatively acquired surface meshes to preoperative planning data is proposed. The key idea of the method is to describe the nonrigid registration process as an electrostatic–elastic problem, where an elastic body (preoperative model) that is electrically charged slides into an oppositely charged rigid shape (intraoperative surface). It is shown that the corresponding energy functional can be efficiently solved using the finite element (FE) method. It is also demonstrated how PBSM can be combined with rigid registration schemes for robust nonrigid registration of arbitrarily aligned surfaces. Furthermore, it is shown how the approach can be combined with landmark based methods and outline its application to image guidance in laparoscopic interventions. Results: A profound analysis of the PBSM scheme based on in silico and phantom data is presented. Simulation studies on several liver models show that the approach is robust to the initial rigid registration and to parameter variations. The studies also reveal that the method achieves submillimeter registration accuracy (mean error between 0.32 and 0.46 mm). An unoptimized, single core implementation of the approach achieves near real-time performance (2 TPS, 7–19 s total registration time). It outperforms established methods in terms of speed and accuracy. Furthermore, it is shown that the

Development of a portable computed tomographic scanner for on-line imaging of industrial piping systems

International Nuclear Information System (INIS)

Jaafar Abdullah; Mohd Arif Hamzah; Mohd Soyapi Mohd Yusof; Mohd Fitri Abdul Rahman; Fadil IsmaiI; Rasif Mohd Zain

2003-01-01

Computed tomography (CT) technology is being increasingly developed for industrial application. This paper presents the development of a portable computed tomographic scanner for on?line imaging of industrial piping systems. The theoretical approach, the system hardware, the data acquisition system and the adopted algorithm for image reconstruction are discussed. The scanner has large potential to be used to determine the extent of corrosion under insulation (CUI), to detect blockages, to measure the thickness of deposit/materials built-up on the walls and to improve understanding of material flow in pipelines. (Author)

Development of JOYO operational guidance system for emergency condition

International Nuclear Information System (INIS)

Takatsuto, Hiroshi; Owada, Toshio; Morimoto, Makoto; Aoki, Hiroshi; Tokita, Mitsuhiko; Terunuma, Seiichi

1989-01-01

Operational guidance system in JOYO has been developed for safe and stable plant operations and improvement of operational reliability. JOYCAT (JOYO Consulting and Analysing Tool), one of the JOYO operational guidance systems, supports the plant operator to present the causal alarm and select the suitable guidance manual in anomaly situations using artificial intelligence technology. Verification test of JOYCAT was performed using a JOYO operator-training simulator and on-line operation was started by partially linking to the actual plant in May 1988. As the result, the proper diagnosis function was confirmed in the actual plant. (author)

Off-line data processing and display for computed tomographic images (EMI brain)

International Nuclear Information System (INIS)

Takizawa, Masaomi; Maruyama, Kiyoshi; Yano, Kesato; Takenaka, Eiichi.

1978-01-01

Processing and multi-format display for the CT (EMI) scan data have been tried by using an off-line small computer and an analog memory. Four or six CT images after processing are displayed on the CRT by a small computer with a 16 kilo-words core memory and an analog memory. Multi-format display of the CT image can be selected as follows; multi-slice display, continuative multi-window display, separate multi-window display, and multi-window level display. Electronic zooming for the real size viewing can give magnified CT image with one of displayed images if necessary. Image substraction, edge enhancement, smoothing, non-linear gray scale display, and synthesized image for the plane tomography reconstracted by the normal CT scan data, have been tried by the off-line data processing. A possibility for an effective application of the data base with CT image was obtained by these trials. (auth.)

Highly parallel line-based image coding for many cores.

Science.gov (United States)

Peng, Xiulian; Xu, Jizheng; Zhou, You; Wu, Feng

2012-01-01

Computers are developing along with a new trend from the dual-core and quad-core processors to ones with tens or even hundreds of cores. Multimedia, as one of the most important applications in computers, has an urgent need to design parallel coding algorithms for compression. Taking intraframe/image coding as a start point, this paper proposes a pure line-by-line coding scheme (LBLC) to meet the need. In LBLC, an input image is processed line by line sequentially, and each line is divided into small fixed-length segments. The compression of all segments from prediction to entropy coding is completely independent and concurrent at many cores. Results on a general-purpose computer show that our scheme can get a 13.9 times speedup with 15 cores at the encoder and a 10.3 times speedup at the decoder. Ideally, such near-linear speeding relation with the number of cores can be kept for more than 100 cores. In addition to the high parallelism, the proposed scheme can perform comparatively or even better than the H.264 high profile above middle bit rates. At near-lossless coding, it outperforms H.264 more than 10 dB. At lossless coding, up to 14% bit-rate reduction is observed compared with H.264 lossless coding at the high 4:4:4 profile.

Epifluorescent imaging study of the effect of anti-diabetic drug metformin on colorectal cancer cell lines in vitro

Directory of Open Access Journals (Sweden)

Venkatasubramani P

2017-12-01

Full Text Available Metformin, a widely used anti-diabetic drug, has recently been associated with inhibition of cell proliferation in multiple cancers. However, it is not clear if the reduction in proliferation on treatment with metformin is a result of cell death or slowdown in the rate of growth of cancer cells, because cell viability assays measure only the number of cells at the beginning and end of the experiment. The aim of this study is to utilize a fluorescent imaging technique to directly follow cell death overtime in order to investigate the effect of metformin on colorectal cancer cells HCT116 and SW480. Epifluorescent imaging analysis carried out using ImageXpress Micro XLS High-Content Imaging System show that there is no significant change in cell death observed in the cancer cell lines, as compared to the control, over multiple closely spaced time points, suggesting that metformin in pharmacological doses may not be an effective inducer of cell death in these colon cancer cell lines.

Multidirectional Scanning Model, MUSCLE, to Vectorize Raster Images with Straight Lines

Directory of Open Access Journals (Sweden)

Ibrahim Baz

2008-04-01

Full Text Available This paper presents a new model, MUSCLE (Multidirectional Scanning for Line Extraction, for automatic vectorization of raster images with straight lines. The algorithm of the model implements the line thinning and the simple neighborhood methods to perform vectorization. The model allows users to define specified criteria which are crucial for acquiring the vectorization process. In this model, various raster images can be vectorized such as township plans, maps, architectural drawings, and machine plans. The algorithm of the model was developed by implementing an appropriate computer programming and tested on a basic application. Results, verified by using two well known vectorization programs (WinTopo and Scan2CAD, indicated that the model can successfully vectorize the specified raster data quickly and accurately.

Quality Assurance of Onboard Megavoltage Computed Tomography Imaging and Target Localization Systems for On- and Off-Line Image-Guided Radiotherapy

International Nuclear Information System (INIS)

Langen, Katja M.; Meeks, Sanford L.; Pouliot, Jean

2008-01-01

We reviewed the quality assurance procedures that have been used to test fan- and cone-beam megavoltage-based in-room imaging systems. Phantom-based tests have been used to establish the geometric accuracy and precision of megavoltage-based systems. However, the clinical implementation of any system is accompanied by challenges that are best tested in a clinical setting using clinical images. To objectively judge and monitor image quality, a set of standard tests and phantoms can be used. The image noise and spatial and contrast resolution have been assessed using standard computed tomography phantoms. The dose to the patient resulting from the imaging procedure can be determined using calculations or measurements. The off-line use of patient images is of interest for the evaluation of dosimetric changes throughout the treatment course. The accuracy of the dosimetric calculations based on the megavoltage images has been tested for the fan- and cone-beam systems. Some of the described tests are typically performed before the clinical implementation of the imaging system; others are suited to monitor the system's performances

An analysis of line-drawings based upon automatically inferred grammar and its application to chest x-ray images

International Nuclear Information System (INIS)

Nakayama, Akira; Yoshida, Yuuji; Fukumura, Teruo

1984-01-01

There is a technique using inferring grammer as image- structure analyzing technique. This technique involves a few problems if it is applied to naturally obtained images, as the practical grammatical technique for two-dimensional image is not established. The authors developed a technique which solved the above problems for the main purpose of the automated structure analysis of naturally obtained image. The first half of this paper describes on the automatic inference of line drawing generation grammar and the line drawing analysis based on that automatic inference. The second half of the paper reports on the actual analysis. The proposed technique is that to extract object line drawings out of the line drawings containing noise. The technique was evaluated for its effectiveness with an example of extracting rib center lines out of thin line chest X-ray images having practical scale and complexity. In this example, the total number of characteristic points (ends, branch points and intersections) composing line drawings per one image was 377, and the total number of line segments composing line drawings was 566 on average per sheet. The extraction ratio was 86.6 % which seemed to be proper when the complexity of input line drawings was considered. Further, the result was compared with the identified rib center lines with the automatic screening system AISCR-V3 for comparison with the conventional processing technique, and it was satisfactory when the versatility of this method was considered. (Wakatsuki, Y.)

General RMP Guidance - Appendix D: OSHA Guidance on PSM

Science.gov (United States)

OSHA's Process Safety Management (PSM) Guidance on providing complete and accurate written information concerning process chemicals, process technology, and process equipment; including process hazard analysis and material safety data sheets.

ALMA MULTI-LINE IMAGING OF THE NEARBY STARBURST NGC 253

Energy Technology Data Exchange (ETDEWEB)

Meier, David S. [New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States); Walter, Fabian; Zschaechner, Laura K. [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Bolatto, Alberto D.; Veilleux, Sylvain; Warren, Steven R. [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Ott, Jürgen [National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States); Rosolowsky, Erik [Department of Physics, University of Alberta, Edmonton, AB T6G 2E1 (Canada); Weiß, Axel [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zwaan, Martin A., E-mail: dmeier@nmt.edu [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)

2015-03-01

We present spatially resolved (∼50 pc) imaging of molecular gas species in the central kiloparsec of the nearby starburst galaxy NGC 253, based on observations taken with the Atacama Large Millimeter/submillimeter Array. A total of 50 molecular lines are detected over a 13 GHz bandwidth imaged in the 3 mm band. Unambiguous identifications are assigned for 27 lines. Based on the measured high CO/C{sup 17}O isotopic line ratio (≳350), we show that {sup 12}CO(1-0) has moderate optical depths. A comparison of the HCN and HCO{sup +} with their {sup 13}C-substituted isotopologues shows that the HCN(1-0) and HCO{sup +}(1-0) lines have optical depths at least comparable to CO(1-0). H{sup 13}CN/H{sup 13}CO{sup +} (and H{sup 13}CN/HN{sup 13}C) line ratios provide tighter constraints on dense gas properties in this starburst. SiO has elevated abundances across the nucleus. HNCO has the most distinctive morphology of all the bright lines, with its global luminosity dominated by the outer parts of the central region. The dramatic variation seen in the HNCO/SiO line ratio suggests that some of the chemical signatures of shocked gas are being erased in the presence of dominating central radiation fields (traced by C{sub 2}H and CN). High density molecular gas tracers (including HCN, HCO{sup +}, and CN) are detected at the base of the molecular outflow. We also detect hydrogen β recombination lines that, like their α counterparts, show compact, centrally peaked morphologies, distinct from the molecular gas tracers. A number of sulfur based species are mapped (CS, SO, NS, C{sub 2}S, H{sub 2}CS, and CH{sub 3}SH) and have morphologies similar to SiO.

Laser line scan underwater imaging by complementary metal-oxide-semiconductor camera

Science.gov (United States)

He, Zhiyi; Luo, Meixing; Song, Xiyu; Wang, Dundong; He, Ning

2017-12-01

This work employs the complementary metal-oxide-semiconductor (CMOS) camera to acquire images in a scanning manner for laser line scan (LLS) underwater imaging to alleviate backscatter impact of seawater. Two operating features of the CMOS camera, namely the region of interest (ROI) and rolling shutter, can be utilized to perform image scan without the difficulty of translating the receiver above the target as the traditional LLS imaging systems have. By the dynamically reconfigurable ROI of an industrial CMOS camera, we evenly divided the image into five subareas along the pixel rows and then scanned them by changing the ROI region automatically under the synchronous illumination by the fun beams of the lasers. Another scanning method was explored by the rolling shutter operation of the CMOS camera. The fun beam lasers were turned on/off to illuminate the narrow zones on the target in a good correspondence to the exposure lines during the rolling procedure of the camera's electronic shutter. The frame synchronization between the image scan and the laser beam sweep may be achieved by either the strobe lighting output pulse or the external triggering pulse of the industrial camera. Comparison between the scanning and nonscanning images shows that contrast of the underwater image can be improved by our LLS imaging techniques, with higher stability and feasibility than the mechanically controlled scanning method.

Towards 4D intervention guidance using compressed sensing

Energy Technology Data Exchange (ETDEWEB)

Kuntz, Jan; Bartling, Soenke [Deutsches Krebsforschungszentrum DKFZ, Heidelberg (Germany); Brehm, Marcus; Kachelriess, Marc [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. of Medical Physics (IMP)

2011-07-01

Interventional radiology is nowadays usually guided with projection radiography using mono- or biplane systems. Due to the projective nature of this guidance imaging certain intraprocedural situations remain unclear. Although helpful, the use of 3D CT is limited due to radiation dose. Using advanced reconstruction techniques incorporating prior knowledge, one could overcome these limitations without exceeding dose limitations. Intervention guidance is especially appealing to those algorithms, because certain constrains apply to useful images in intervention guidance that vary relevantly from other CT applications. These are: key relevance of high contrast structures, sparse temporal updates and little relevance of absolute CT values. In this paper the principal usability of reconstruction algorithms for intervention guidance is tested. Compressed sensing algorithms PICCS and ASD-POCS are compared to the McKinnon-Bates and Feldkamp-Davis-Kress algorithm. Animal experiments as well as simulations are performed. An outlook towards 4D intervention guidance is provided. (orig.)

A heuristic approach to edge detection in on-line portal imaging

International Nuclear Information System (INIS)

McGee, Kiaran P.; Schultheiss, Timothy E.; Martin, Eric E.

1995-01-01

Purpose: Portal field edge detection is an essential component of several postprocessing techniques used in on-line portal imaging, including field shape verification, selective contrast enhancement, and treatment setup error detection. Currently edge detection of successive fractions in a multifraction portal image series involves the repetitive application of the same algorithm. As the number of changes in the field is small compared to the total number of fractions, standard edge detection algorithms essentially recalculate the same field shape numerous times. A heuristic approach to portal edge detection has been developed that takes advantage of the relatively few changes in the portal field shape throughout a fractionation series. Methods and Materials: The routine applies a standard edge detection routine to calculate an initial field edge and saves the edge information. Subsequent fractions are processed by applying an edge detection operator over a small region about each point of the previously defined contour, to determine any shifts in the field shape in the new image. Failure of this edge check indicates that a significant change in the field edge has occurred, and the original edge detection routine is applied to the image. Otherwise the modified edge contour is used to define the new edge. Results: Two hundred and eighty-one portal images collected from an electronic portal imaging device were processed by the edge detection routine. The algorithm accurately calculated each portal field edge, as well as reducing processing time in subsequent fractions of an individual portal field by a factor of up to 14. Conclusions: The heuristic edge detection routine is an accurate and fast method for calculating portal field edges and determining field edge setup errors

EXTRACTION OF ROOF LINES FROM HIGH-RESOLUTION IMAGES BY A GROUPING METHOD

Directory of Open Access Journals (Sweden)

A. P. Dal Poz

2016-06-01

Full Text Available This paper proposes a method for extracting groups of straight lines that represent roof boundaries and roof ridgelines from highresolution aerial images using corresponding Airborne Laser Scanner (ALS roof polyhedrons as initial approximations. The proposed method is based on two main steps. First, straight lines that are candidates to represent roof ridgelines and roof boundaries of a building are extracted from the aerial image. Second, a group of straight lines that represent roof boundaries and roof ridgelines of a selected building is obtained through the optimization of a Markov Random Field (MRF-based energy function using the genetic algorithm optimization method. The formulation of this energy function considers several attributes, such as the proximity of the extracted straight lines to the corresponding projected ALS-derived roof polyhedron and the rectangularity (extracted straight lines that intersect at nearly 90°. Experimental results are presented and discussed in this paper.

In-Line Sorting of Harumanis Mango Based on External Quality Using Visible Imaging.

Science.gov (United States)

Ibrahim, Mohd Firdaus; Ahmad Sa'ad, Fathinul Syahir; Zakaria, Ammar; Md Shakaff, Ali Yeon

2016-10-27

The conventional method of grading Harumanis mango is time-consuming, costly and affected by human bias. In this research, an in-line system was developed to classify Harumanis mango using computer vision. The system was able to identify the irregularity of mango shape and its estimated mass. A group of images of mangoes of different size and shape was used as database set. Some important features such as length, height, centroid and parameter were extracted from each image. Fourier descriptor and size-shape parameters were used to describe the mango shape while the disk method was used to estimate the mass of the mango. Four features have been selected by stepwise discriminant analysis which was effective in sorting regular and misshapen mango. The volume from water displacement method was compared with the volume estimated by image processing using paired t -test and Bland-Altman method. The result between both measurements was not significantly different (P > 0.05). The average correct classification for shape classification was 98% for a training set composed of 180 mangoes. The data was validated with another testing set consist of 140 mangoes which have the success rate of 92%. The same set was used for evaluating the performance of mass estimation. The average success rate of the classification for grading based on its mass was 94%. The results indicate that the in-line sorting system using machine vision has a great potential in automatic fruit sorting according to its shape and mass.

Regional information guidance system based on hypermedia concept

Science.gov (United States)

Matoba, Hiroshi; Hara, Yoshinori; Kasahara, Yutako

1990-08-01

A regional information guidance system has been developed on an image workstation. Two main features of this system are hypermedia data structure and friendly visual interface realized by the full-color frame memory system. As the hypermedia data structure manages regional information such as maps, pictures and explanations of points of interest, users can retrieve those information one by one, next to next according to their interest change. For example, users can retrieve explanation of a picture through the link between pictures and text explanations. Users can also traverse from one document to another by using keywords as cross reference indices. The second feature is to utilize a full-color, high resolution and wide space frame memory for visual interface design. This frame memory system enables real-time operation of image data and natural scene representation. The system also provides half tone representing function which enables fade-in/out presentations. This fade-in/out functions used in displaying and erasing menu and image data, makes visual interface soft for human eyes. The system we have developed is a typical example of multimedia applications. We expect the image workstation will play an important role as a platform for multimedia applications.

Fusion Imaging for Procedural Guidance.

Science.gov (United States)

Wiley, Brandon M; Eleid, Mackram F; Thaden, Jeremy J

2018-05-01

The field of percutaneous structural heart interventions has grown tremendously in recent years. This growth has fueled the development of new imaging protocols and technologies in parallel to help facilitate these minimally-invasive procedures. Fusion imaging is an exciting new technology that combines the strength of 2 imaging modalities and has the potential to improve procedural planning and the safety of many commonly performed transcatheter procedures. In this review we discuss the basic concepts of fusion imaging along with the relative strengths and weaknesses of static vs dynamic fusion imaging modalities. This review will focus primarily on echocardiographic-fluoroscopic fusion imaging and its application in commonly performed transcatheter structural heart procedures. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

In-beam PET imaging for on-line adaptive proton therapy: an initial phantom study

Science.gov (United States)

Shao, Yiping; Sun, Xishan; Lou, Kai; Zhu, Xiaorong R.; Mirkovic, Dragon; Poenisch, Falk; Grosshans, David

2014-07-01

We developed and investigated a positron emission tomography (PET) system for use with on-line (both in-beam and intra-fraction) image-guided adaptive proton therapy applications. The PET has dual rotating depth-of-interaction measurable detector panels by using solid-state photomultiplier (SSPM) arrays and LYSO scintillators. It has a 44 mm diameter trans-axial and 30 mm axial field-of-view (FOV). A 38 mm diameter polymethyl methacrylate phantom was placed inside the FOV. Both PET and phantom axes were aligned with a collimated 179.2 MeV beam. Each beam delivered ˜50 spills (0.5 s spill and 1.5 s inter-spill time, 3.8 Gy at Bragg peak). Data from each beam were acquired with detectors at a given angle. Nine datasets for nine beams with detectors at nine different angles over 180° were acquired for full-tomographic imaging. Each dataset included data both during and 5 min after irradiations. The positron activity-range was measured from the PET image reconstructed from all nine datasets and compared to the results from simulated images. A 22Na disc-source was also imaged after each beam to monitor the PET system's performance. PET performed well except for slight shifts of energy photo-peak positions (<1%) after each beam, due mainly to the neutron exposure of SSPM that increased the dark-count noise. This minor effect was corrected offline with a shifting 350-650 keV energy window for each dataset. The results show a fast converging of activity-ranges measured by the prototype PET with high sensitivity and uniform resolution. Sub-mm activity-ranges were achieved with minimal 6 s acquisition time and three spill irradiations. These results indicate the feasibility of PET for intra-fraction beam-range verification. Further studies are needed to develop and apply a novel clinical PET system for on-line image-guided adaptive proton therapy.

Confocal non-line-of-sight imaging based on the light-cone transform

Science.gov (United States)

O’Toole, Matthew; Lindell, David B.; Wetzstein, Gordon

2018-03-01

How to image objects that are hidden from a camera’s view is a problem of fundamental importance to many fields of research, with applications in robotic vision, defence, remote sensing, medical imaging and autonomous vehicles. Non-line-of-sight (NLOS) imaging at macroscopic scales has been demonstrated by scanning a visible surface with a pulsed laser and a time-resolved detector. Whereas light detection and ranging (LIDAR) systems use such measurements to recover the shape of visible objects from direct reflections, NLOS imaging reconstructs the shape and albedo of hidden objects from multiply scattered light. Despite recent advances, NLOS imaging has remained impractical owing to the prohibitive memory and processing requirements of existing reconstruction algorithms, and the extremely weak signal of multiply scattered light. Here we show that a confocal scanning procedure can address these challenges by facilitating the derivation of the light-cone transform to solve the NLOS reconstruction problem. This method requires much smaller computational and memory resources than previous reconstruction methods do and images hidden objects at unprecedented resolution. Confocal scanning also provides a sizeable increase in signal and range when imaging retroreflective objects. We quantify the resolution bounds of NLOS imaging, demonstrate its potential for real-time tracking and derive efficient algorithms that incorporate image priors and a physically accurate noise model. Additionally, we describe successful outdoor experiments of NLOS imaging under indirect sunlight.

MO-DE-202-00: Image-Guided Interventions: Advances in Intraoperative Imaging, Guidance, and An Emerging Role for Medical Physics in Surgery

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

At least three major trends in surgical intervention have emerged over the last decade: a move toward more minimally invasive (or non-invasive) approach to the surgical target; the development of high-precision treatment delivery techniques; and the increasing role of multi-modality intraoperative imaging in support of such procedures. This symposium includes invited presentations on recent advances in each of these areas and the emerging role for medical physics research in the development and translation of high-precision interventional techniques. The four speakers are: Keyvan Farahani, “Image-guided focused ultrasound surgery and therapy” Jeffrey H. Siewerdsen, “Advances in image registration and reconstruction for image-guided neurosurgery” Tina Kapur, “Image-guided surgery and interventions in the advanced multimodality image-guided operating (AMIGO) suite” Raj Shekhar, “Multimodality image-guided interventions: Multimodality for the rest of us” Learning Objectives: Understand the principles and applications of HIFU in surgical ablation. Learn about recent advances in 3D–2D and 3D deformable image registration in support of surgical safety and precision. Learn about recent advances in model-based 3D image reconstruction in application to intraoperative 3D imaging. Understand the multi-modality imaging technologies and clinical applications investigated in the AMIGO suite. Understand the emerging need and techniques to implement multi-modality image guidance in surgical applications such as neurosurgery, orthopaedic surgery, vascular surgery, and interventional radiology. Research supported by the NIH and Siemens Healthcare.; J. Siewerdsen; Grant Support - National Institutes of Health; Grant Support - Siemens Healthcare; Grant Support - Carestream Health; Advisory Board - Carestream Health; Licensing Agreement - Carestream Health; Licensing Agreement - Elekta Oncology.; T. Kapur, P41EB015898; R. Shekhar, Funding: R42CA137886 and R41CA192504

A multimodal imaging framework for enhanced robot-assisted partial nephrectomy guidance

Science.gov (United States)

Halter, Ryan J.; Wu, Xiaotian; Hartov, Alex; Seigne, John; Khan, Shadab

2015-03-01

Robot-assisted laparoscopic partial nephrectomies (RALPN) are performed to treat patients with locally confined renal carcinoma. There are well-documented benefits to performing partial (opposed to radical) kidney resections and to using robot-assisted laparoscopic (opposed to open) approaches. However, there are challenges in identifying tumor margins and critical benign structures including blood vessels and collecting systems during current RALPN procedures. The primary objective of this effort is to couple multiple image and data streams together to augment visual information currently provided to surgeons performing RALPN and ultimately ensure complete tumor resection and minimal damage to functional structures (i.e. renal vasculature and collecting systems). To meet this challenge we have developed a framework and performed initial feasibility experiments to couple pre-operative high-resolution anatomic images with intraoperative MRI, ultrasound (US) and optical-based surface mapping and kidney tracking. With these registered images and data streams, we aim to overlay the high-resolution contrast-enhanced anatomic (CT or MR) images onto the surgeon's view screen for enhanced guidance. To date we have integrated the following components of our framework: 1) a method for tracking an intraoperative US probe to extract the kidney surface and a set of embedded kidney markers, 2) a method for co-registering intraoperative US scans with pre-operative MR scans, and 3) a method for deforming pre-op scans to match intraoperative scans. These components have been evaluated through phantom studies to demonstrate protocol feasibility.

Mechatronic track guidance on disturbed track: the trade-off between actuator performance and wheel wear

Science.gov (United States)

Kurzeck, Bernhard; Heckmann, Andreas; Wesseler, Christoph; Rapp, Matthias

2014-05-01

Future high-speed trains are the main focus of the DLR research project Next Generation Train. One central point of the research activities is the development of mechatronic track guidance for the two-axle intermediate wagons with steerable, individually powered, independently rotating wheels. The traction motors hereby fulfil two functions; they concurrently are traction drives and steering actuators. In this paper, the influence of the track properties - line layout and track irregularities - on the performance requirements for the guidance actuator is investigated using multi-body models in SIMPACK®. In order to compromise on the design conflict between low wheel wear and low steering torque, the control parameters of the mechatronic track guidance are optimised using the DLR in-house software MOPS. Besides the track irregularities especially the increasing inclination at transition curves defines high actuator requirements due to gyroscopic effects at high speed. After introducing a limiter for the actuating variables into the control system, a good performance is achieved.

Large-scale building scenes reconstruction from close-range images based on line and plane feature

Science.gov (United States)

Ding, Yi; Zhang, Jianqing

2007-11-01

Automatic generate 3D models of buildings and other man-made structures from images has become a topic of increasing importance, those models may be in applications such as virtual reality, entertainment industry and urban planning. In this paper we address the main problems and available solution for the generation of 3D models from terrestrial images. We first generate a coarse planar model of the principal scene planes and then reconstruct windows to refine the building models. There are several points of novelty: first we reconstruct the coarse wire frame model use the line segments matching with epipolar geometry constraint; Secondly, we detect the position of all windows in the image and reconstruct the windows by established corner points correspondences between images, then add the windows to the coarse model to refine the building models. The strategy is illustrated on image triple of college building.

Integrated guidance and control design of a flight vehicle with side-window detection

Directory of Open Access Journals (Sweden)

Tianyu ZHENG

2018-04-01

Full Text Available This paper considers the guidance and control problem of a flight vehicle with side-window detection. In order to guarantee the target remaining in the seeker's sight of view, the line of sight and the attitude of the flight vehicle should be under some constraints caused by the side-window, which leads to coupling between the guidance and the attitude dynamics model. To deal with the side-window constraints and the coupling, a novel Integrated Guidance and Control (IGC design approach is proposed. Firstly, the relative motion equations are derived in the body-Line of Sight (LOS coordinate system. And the guidance and control problem of the flight vehicle is formulated into an IGC problem with state constraints. Then, based on the singular perturbation method, the IGC problem is decomposed into the control design of the quasi-steady-state subsystem and the boundary-layer subsystem which can be designed separately. Finally, the receding horizon control is applied to the control design for the two subsystems. Simulation results show the effectiveness of the proposed approach. Keywords: Integrated guidance and control, Receding horizon control, Side-window detection, Singular perturbation, Terminal guidance

Simulation and experimental research on line throwing rocket with flight

Directory of Open Access Journals (Sweden)

Wen-bin Gu

2014-06-01

Full Text Available The finite segment method is used to model the line throwing rocket system. A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system and the consideration of the forces acting on the system. The experiment designed according to the parameters of the dynamic model is made. The simulation and experiment results, such as range, velocity and flight time, are compared and analyzed. The simulation results are basically agreed with the test data, which shows that the flight motion of the line throwing rocket can be predicted by the dynamic model. A theoretical model and guide for the further research on the disturbance of rope and the guidance, flight control of line throwing rocket are provided by the dynamic modeling.

A nurse led peripherally inserted central catheter line insertion service is effective with radiological support

International Nuclear Information System (INIS)

Barber, Jonathan M.; Booth, Doris M.; King, Julia A.; Chakraverty, Sam

2002-01-01

AIM: Peripherally inserted central catheters (PICC) are increasingly used as a route of chemotherapy administration. Our aims were to assess a collaborative approach to PICC placement, with radiological support for a nurse led line insertion service in a minority of cases, and to determine whether PICC provided a safe and reliable method of chemotherapy administration. MATERIALS AND METHODS: Prospective data on 100 consecutive patients undergoing PICC placement for chemotherapy were collected. Lines were inserted by ward based nurses or under ultrasound guidance by radiologists. End points were successful completion of treatment or patient death. RESULTS: One hundred and forty-four lines were placed for 118 courses of chemotherapy. 107 (74%) were placed by nurses and 37 (26%) by radiologists. Ninety-five percent of patients completed therapy with either one or two lines. Seventy percent of lines were removed on achieving the primary end points. In two additional patients PICC could not be placed radiologically. Twelve patients were unable to complete treatment with PICC alone, nine of these required an alternative administration route. The catheter related sepsis rate was 4.9%. CONCLUSION: The majority of PICC can be successfully placed by trained nurses, reserving image guidance only for more difficult cases. PICC have an acceptable complication profile, and decrease the need for tunnelled central lines. Barber, J.M. et al. (2002)

In-Line Sorting of Harumanis Mango Based on External Quality Using Visible Imaging

Science.gov (United States)

Ibrahim, Mohd Firdaus; Ahmad Sa’ad, Fathinul Syahir; Zakaria, Ammar; Md Shakaff, Ali Yeon

2016-01-01

The conventional method of grading Harumanis mango is time-consuming, costly and affected by human bias. In this research, an in-line system was developed to classify Harumanis mango using computer vision. The system was able to identify the irregularity of mango shape and its estimated mass. A group of images of mangoes of different size and shape was used as database set. Some important features such as length, height, centroid and parameter were extracted from each image. Fourier descriptor and size-shape parameters were used to describe the mango shape while the disk method was used to estimate the mass of the mango. Four features have been selected by stepwise discriminant analysis which was effective in sorting regular and misshapen mango. The volume from water displacement method was compared with the volume estimated by image processing using paired t-test and Bland-Altman method. The result between both measurements was not significantly different (P > 0.05). The average correct classification for shape classification was 98% for a training set composed of 180 mangoes. The data was validated with another testing set consist of 140 mangoes which have the success rate of 92%. The same set was used for evaluating the performance of mass estimation. The average success rate of the classification for grading based on its mass was 94%. The results indicate that the in-line sorting system using machine vision has a great potential in automatic fruit sorting according to its shape and mass. PMID:27801799

In-Line Sorting of Harumanis Mango Based on External Quality Using Visible Imaging

Directory of Open Access Journals (Sweden)

Mohd Firdaus Ibrahim

2016-10-01

Full Text Available The conventional method of grading Harumanis mango is time-consuming, costly and affected by human bias. In this research, an in-line system was developed to classify Harumanis mango using computer vision. The system was able to identify the irregularity of mango shape and its estimated mass. A group of images of mangoes of different size and shape was used as database set. Some important features such as length, height, centroid and parameter were extracted from each image. Fourier descriptor and size-shape parameters were used to describe the mango shape while the disk method was used to estimate the mass of the mango. Four features have been selected by stepwise discriminant analysis which was effective in sorting regular and misshapen mango. The volume from water displacement method was compared with the volume estimated by image processing using paired t-test and Bland-Altman method. The result between both measurements was not significantly different (P > 0.05. The average correct classification for shape classification was 98% for a training set composed of 180 mangoes. The data was validated with another testing set consist of 140 mangoes which have the success rate of 92%. The same set was used for evaluating the performance of mass estimation. The average success rate of the classification for grading based on its mass was 94%. The results indicate that the in-line sorting system using machine vision has a great potential in automatic fruit sorting according to its shape and mass.

Quality assurance and quality control in mammography: a review of available guidance worldwide.

Science.gov (United States)

Reis, Cláudia; Pascoal, Ana; Sakellaris, Taxiarchis; Koutalonis, Manthos

2013-10-01

Review available guidance for quality assurance (QA) in mammography and discuss its contribution to harmonise practices worldwide. Literature search was performed on different sources to identify guidance documents for QA in mammography available worldwide in international bodies, healthcare providers, professional/scientific associations. The guidance documents identified were reviewed and a selection was compared for type of guidance (clinical/technical), technology and proposed QA methodologies focusing on dose and image quality (IQ) performance assessment. Fourteen protocols (targeted at conventional and digital mammography) were reviewed. All included recommendations for testing acquisition, processing and display systems associated with mammographic equipment. All guidance reviewed highlighted the importance of dose assessment and testing the Automatic Exposure Control (AEC) system. Recommended tests for assessment of IQ showed variations in the proposed methodologies. Recommended testing focused on assessment of low-contrast detection, spatial resolution and noise. QC of image display is recommended following the American Association of Physicists in Medicine guidelines. The existing QA guidance for mammography is derived from key documents (American College of Radiology and European Union guidelines) and proposes similar tests despite the variations in detail and methodologies. Studies reported on QA data should provide detail on experimental technique to allow robust data comparison. Countries aiming to implement a mammography/QA program may select/prioritise the tests depending on available technology and resources. •An effective QA program should be practical to implement in a clinical setting. •QA should address the various stages of the imaging chain: acquisition, processing and display. •AEC system QC testing is simple to implement and provides information on equipment performance.

Registration of angiographic image on real-time fluoroscopic image for image-guided percutaneous coronary intervention.

Science.gov (United States)

Kim, Dongkue; Park, Sangsoo; Jeong, Myung Ho; Ryu, Jeha

2018-02-01

In percutaneous coronary intervention (PCI), cardiologists must study two different X-ray image sources: a fluoroscopic image and an angiogram. Manipulating a guidewire while alternately monitoring the two separate images on separate screens requires a deep understanding of the anatomy of coronary vessels and substantial training. We propose 2D/2D spatiotemporal image registration of the two images in a single image in order to provide cardiologists with enhanced visual guidance in PCI. The proposed 2D/2D spatiotemporal registration method uses a cross-correlation of two ECG series in each image to temporally synchronize two separate images and register an angiographic image onto the fluoroscopic image. A guidewire centerline is then extracted from the fluoroscopic image in real time, and the alignment of the centerline with vessel outlines of the chosen angiographic image is optimized using the iterative closest point algorithm for spatial registration. A proof-of-concept evaluation with a phantom coronary vessel model with engineering students showed an error reduction rate greater than 74% on wrong insertion to nontarget branches compared to the non-registration method and more than 47% reduction in the task completion time in performing guidewire manipulation for very difficult tasks. Evaluation with a small number of experienced doctors shows a potentially significant reduction in both task completion time and error rate for difficult tasks. The total registration time with real procedure X-ray (angiographic and fluoroscopic) images takes [Formula: see text] 60 ms, which is within the fluoroscopic image acquisition rate of 15 Hz. By providing cardiologists with better visual guidance in PCI, the proposed spatiotemporal image registration method is shown to be useful in advancing the guidewire to the coronary vessel branches, especially those difficult to insert into.

Techniques for Interventional MRI Guidance in Closed-Bore Systems.

Science.gov (United States)

Busse, Harald; Kahn, Thomas; Moche, Michael

2018-02-01

Efficient image guidance is the basis for minimally invasive interventions. In comparison with X-ray, computed tomography (CT), or ultrasound imaging, magnetic resonance imaging (MRI) provides the best soft tissue contrast without ionizing radiation and is therefore predestined for procedural control. But MRI is also characterized by spatial constraints, electromagnetic interactions, long imaging times, and resulting workflow issues. Although many technical requirements have been met over the years-most notably magnetic resonance (MR) compatibility of tools, interventional pulse sequences, and powerful processing hardware and software-there is still a large variety of stand-alone devices and systems for specific procedures only.Stereotactic guidance with the table outside the magnet is common and relies on proper registration of the guiding grids or manipulators to the MR images. Instrument tracking, often by optical sensing, can be added to provide the physicians with proper eye-hand coordination during their navigated approach. Only in very short wide-bore systems, needles can be advanced at the extended arm under near real-time imaging. In standard magnets, control and workflow may be improved by remote operation using robotic or manual driving elements.This work highlights a number of devices and techniques for different interventional settings with a focus on percutaneous, interstitial procedures in different organ regions. The goal is to identify technical and procedural elements that might be relevant for interventional guidance in a broader context, independent of the clinical application given here. Key challenges remain the seamless integration into the interventional workflow, safe clinical translation, and proper cost effectiveness.

Accuracy of Ultrasound-Based Image Guidance for Daily Positioning of the Upper Abdomen: An Online Comparison With Cone Beam CT

International Nuclear Information System (INIS)

Boda-Heggemann, Judit; Mennemeyer, Philipp; Wertz, Hansjoerg; Riesenacker, Nadja; Kuepper, Beate; Lohr, Frank; Wenz, Frederik

2009-01-01

Purpose: Image-guided intensity-modulated radiotherapy can improve protection of organs at risk when large abdominal target volumes are irradiated. We estimated the daily positioning accuracy of ultrasound-based image guidance for abdominal target volumes by a direct comparison of daily imaging obtained with cone beam computed tomography (CBCT). Methods and Materials: Daily positioning (n = 83 positionings) of 15 patients was completed by using ultrasound guidance after an initial CBCT was obtained. Residual error after ultrasound was estimated by comparison with a second CBCT. Ultrasound image quality was visually rated using a scale of 1 to 4. Results: Of 15 patients, 7 patients had good sonographic imaging quality, 5 patients had satisfactory sonographic quality, and 3 patients were excluded because of unsatisfactory sonographic quality. When image quality was good, residual errors after ultrasound were -0.1 ± 3.11 mm in the x direction (left-right; group systematic error M = -0.09 mm; standard deviation [SD] of systematic error, Σ = 1.37 mm; SD of the random error, σ = 2.99 mm), 0.93 ± 4.31 mm in the y direction (superior-inferior, M = 1.12 mm; Σ = 2.96 mm; σ = 3.39 mm), and 0.71 ± 3.15 mm in the z direction (anteroposterior; M = 1.01 mm; Σ = 2.46 mm; σ = 2.24 mm). For patients with satisfactory image quality, residual error after ultrasound was -0.6 ± 5.26 mm in the x (M = 0.07 mm; Σ = 5.67 mm; σ = 4.86 mm), 1.76 ± 4.92 mm in the y (M = 3.54 mm; Σ = 4.1 mm; σ = 5.29 mm), and 1.19 ± 4.75 mm in the z (M = 0.82 mm; Σ = 2.86 mm; σ = 3.05 mm) directions. Conclusions: In patients from whom good sonographic image quality could be obtained, ultrasound improved daily positioning accuracy. In the case of satisfactory image quality, ultrasound guidance improved accuracy compared to that of skin marks only minimally. If sonographic image quality was unsatisfactory, daily CBCT scanning improved treatment accuracy distinctly over that of ultrasound. Use of

Image guidance quality assurance of a G4 CyberKnife robotic stereotactic radiosurgery system

International Nuclear Information System (INIS)

Pantelis, E; Antypas, C; Petrokokkinos, L

2009-01-01

The image guidance of a CyberKnife robotic radiosurgery system was quality controlled, including the overall performance of the target locating subsystem and the performance of the x-ray generators and flat panel digital cameras subcomponents. Accuracy and precision of the kV and exposure time settings of the x-ray generators, linearity of the x-ray output, spatial resolution and geometrical distortion of the acquired x-ray images were measured. Total accuracy and precision of the target locating subsystem in defining the position of an anthropomorphic head and neck phantom placed on treatment couch was also measured. Accuracy and precision of the kV as well as exposure time settings and linearity of the x-ray output were found within the acceptance limits suggested in diagnostic radiology. The acquired x-ray images were found to depict the shapes of the imaging objects without any geometrical distortion, being able to resolve differences in the features of imaging objects with critical frequency of 1.3 lp/mm and 1.5 lp/mm for camera A and B, respectively. Total target locating system accuracy was found within 0.2 mm and 0.2 deg. in translations and rotations, respectively. Corresponding precision was found lower than 0.5%. These findings render the target locating subsystem of the CyberKnife capable of accurately registering the patient to treatment position and monitoring patient's movement during treatment delivery.

Reference line-pair values of panoramic radiographs using an arch-form phantom stand to assess clinical image quality

International Nuclear Information System (INIS)

Choi, Da Hye; Choi, Bo Ram; Huh, Kyung Hoe; Heo, Min Suk; Choi, Soon Chul; Choi, Jin Woo; Yi, Won Jin; Lee, Sam Sun

2013-01-01

This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.

Reference line-pair values of panoramic radiographs using an arch-form phantom stand to assess clinical image quality

Energy Technology Data Exchange (ETDEWEB)

Choi, Da Hye; Choi, Bo Ram; Huh, Kyung Hoe; Heo, Min Suk; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Choi, Jin Woo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Cheonan (Korea, Republic of); Yi, Won Jin; Lee, Sam Sun [Dept. of Oral and Maxillofacial Radiology, BK21 Craniomaxillofacial Life Science, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

2013-03-15

This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.

Empirical gradient threshold technique for automated segmentation across image modalities and cell lines.

Science.gov (United States)

Chalfoun, J; Majurski, M; Peskin, A; Breen, C; Bajcsy, P; Brady, M

2015-10-01

New microscopy technologies are enabling image acquisition of terabyte-sized data sets consisting of hundreds of thousands of images. In order to retrieve and analyze the biological information in these large data sets, segmentation is needed to detect the regions containing cells or cell colonies. Our work with hundreds of large images (each 21,000×21,000 pixels) requires a segmentation method that: (1) yields high segmentation accuracy, (2) is applicable to multiple cell lines with various densities of cells and cell colonies, and several imaging modalities, (3) can process large data sets in a timely manner, (4) has a low memory footprint and (5) has a small number of user-set parameters that do not require adjustment during the segmentation of large image sets. None of the currently available segmentation methods meet all these requirements. Segmentation based on image gradient thresholding is fast and has a low memory footprint. However, existing techniques that automate the selection of the gradient image threshold do not work across image modalities, multiple cell lines, and a wide range of foreground/background densities (requirement 2) and all failed the requirement for robust parameters that do not require re-adjustment with time (requirement 5). We present a novel and empirically derived image gradient threshold selection method for separating foreground and background pixels in an image that meets all the requirements listed above. We quantify the difference between our approach and existing ones in terms of accuracy, execution speed, memory usage and number of adjustable parameters on a reference data set. This reference data set consists of 501 validation images with manually determined segmentations and image sizes ranging from 0.36 Megapixels to 850 Megapixels. It includes four different cell lines and two image modalities: phase contrast and fluorescent. Our new technique, called Empirical Gradient Threshold (EGT), is derived from this reference

Adapting haptic guidance authority based on user grip

NARCIS (Netherlands)

Smisek, J.; Mugge, W.; Smeets, J.B.J.; Van Paassen, M.M.; Schiele, A

2014-01-01

Haptic guidance systems support the operator in task execution using additional forces on the input device. Scaling of the guidance forces determines the control authority of the support system. As task complexity may vary, one level of the guidance scaling may be insufficient, and adaptation of the

Continuous monitoring of prostate position using stereoscopic and monoscopic kV image guidance

Energy Technology Data Exchange (ETDEWEB)

Stevens, M. Tynan R.; Parsons, Dave D.; Robar, James L. [Department of Medical Physics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada and Nova Scotia Cancer Centre, QEII Health Science Centre, Halifax, Nova Scotia B3H 2Y9 (Canada)

2016-05-15

Purpose: To demonstrate continuous kV x-ray monitoring of prostate motion using both stereoscopic and monoscopic localizations, assess the spatial accuracy of these techniques, and evaluate the dose delivered from the added image guidance. Methods: The authors implemented both stereoscopic and monoscopic fiducial localizations using a room-mounted dual oblique x-ray system. Recently developed monoscopic 3D position estimation techniques potentially overcome the issue of treatment head interference with stereoscopic imaging at certain gantry angles. To demonstrate continuous position monitoring, a gold fiducial marker was placed in an anthropomorphic phantom and placed on the Linac couch. The couch was used as a programmable translation stage. The couch was programmed with a series of patient prostate motion trajectories exemplifying five distinct categories: stable prostate, slow drift, persistent excursion, transient excursion, and high frequency excursions. The phantom and fiducial were imaged using 140 kVp, 0.63 mAs per image at 1 Hz for a 60 s monitoring period. Both stereoscopic and monoscopic 3D localization accuracies were assessed by comparison to the ground-truth obtained from the Linac log file. Imaging dose was also assessed, using optically stimulated luminescence dosimeter inserts in the phantom. Results: Stereoscopic localization accuracy varied between 0.13 ± 0.05 and 0.33 ± 0.30 mm, depending on the motion trajectory. Monoscopic localization accuracy varied from 0.2 ± 0.1 to 1.1 ± 0.7 mm. The largest localization errors were typically observed in the left–right direction. There were significant differences in accuracy between the two monoscopic views, but which view was better varied from trajectory to trajectory. The imaging dose was measured to be between 2 and 15 μGy/mAs, depending on location in the phantom. Conclusions: The authors have demonstrated the first use of monoscopic localization for a room-mounted dual x-ray system. Three

An image guidance system for positioning robotic cochlear implant insertion tools

Science.gov (United States)

Bruns, Trevor L.; Webster, Robert J.

2017-03-01

Cochlear implants must be inserted carefully to avoid damaging the delicate anatomical structures of the inner ear. This has motivated several approaches to improve the safety and efficacy of electrode array insertion by automating the process with specialized robotic or manual insertion tools. When such tools are used, they must be positioned at the entry point to the cochlea and aligned with the desired entry vector. This paper presents an image guidance system capable of accurately positioning a cochlear implant insertion tool. An optical tracking system localizes the insertion tool in physical space while a graphical user interface incorporates this with patient- specific anatomical data to provide error information to the surgeon in real-time. Guided by this interface, novice users successfully aligned the tool with an mean accuracy of 0.31 mm.

Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

Science.gov (United States)

Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.

2009-06-01

Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br

78 FR 12761 - Guidance for Industry: Guidance on the Labeling of Certain Uses of Lecithin Derived From Soy...

Science.gov (United States)

2013-02-25

...] (formerly 2006D-0169) Guidance for Industry: Guidance on the Labeling of Certain Uses of Lecithin Derived... on the Labeling of Certain Uses of Lecithin Derived From Soy Under Section 403(w) of the Federal Food.... The guidance explained FDA's then current thinking on the labeling of certain uses of lecithin derived...

Image matching for digital close-range stereo photogrammetry based on constraints of Delaunay triangulated network and epipolar-line

Science.gov (United States)

Zhang, K.; Sheng, Y. H.; Li, Y. Q.; Han, B.; Liang, Ch.; Sha, W.

2006-10-01

In the field of digital photogrammetry and computer vision, the determination of conjugate points in a stereo image pair, referred to as "image matching," is the critical step to realize automatic surveying and recognition. Traditional matching methods encounter some problems in the digital close-range stereo photogrammetry, because the change of gray-scale or texture is not obvious in the close-range stereo images. The main shortcoming of traditional matching methods is that geometric information of matching points is not fully used, which will lead to wrong matching results in regions with poor texture. To fully use the geometry and gray-scale information, a new stereo image matching algorithm is proposed in this paper considering the characteristics of digital close-range photogrammetry. Compared with the traditional matching method, the new algorithm has three improvements on image matching. Firstly, shape factor, fuzzy maths and gray-scale projection are introduced into the design of synthetical matching measure. Secondly, the topology connecting relations of matching points in Delaunay triangulated network and epipolar-line are used to decide matching order and narrow the searching scope of conjugate point of the matching point. Lastly, the theory of parameter adjustment with constraint is introduced into least square image matching to carry out subpixel level matching under epipolar-line constraint. The new algorithm is applied to actual stereo images of a building taken by digital close-range photogrammetric system. The experimental result shows that the algorithm has a higher matching speed and matching accuracy than pyramid image matching algorithm based on gray-scale correlation.

Automatic localization of the prostate for on-line or off-line image-guided radiotherapy

International Nuclear Information System (INIS)

Smitsmans, Monique H.P.; Wolthaus, Jochem W.H.; Artignan, Xavier; Bois, Josien de; Jaffray, David A.; Lebesque, Joos V.; Herk, Marcel van

2004-01-01

Purpose: With higher radiation dose, higher cure rates have been reported in prostate cancer patients. The extra margin needed to account for prostate motion, however, limits the level of dose escalation, because of the presence of surrounding organs at risk. Knowledge of the precise position of the prostate would allow significant reduction of the treatment field. Better localization of the prostate at the time of treatment is therefore needed, e.g. using a cone-beam computed tomography (CT) system integrated with the linear accelerator. Localization of the prostate relies upon manual delineation of contours in successive axial CT slices or interactive alignment and is fairly time-consuming. A faster method is required for on-line or off-line image-guided radiotherapy, because of prostate motion, for patient throughput and efficiency. Therefore, we developed an automatic method to localize the prostate, based on 3D gray value registration. Methods and materials: A study was performed on conventional repeat CT scans of 19 prostate cancer patients to develop the methodology to localize the prostate. For each patient, 8-13 repeat CT scans were made during the course of treatment. First, the planning CT scan and the repeat CT scan were registered onto the rigid bony structures. Then, the delineated prostate in the planning CT scan was enlarged by an optimum margin of 5 mm to define a region of interest in the planning CT scan that contained enough gray value information for registration. Subsequently, this region was automatically registered to a repeat CT scan using 3D gray value registration to localize the prostate. The performance of automatic prostate localization was compared to prostate localization using contours. Therefore, a reference set was generated by registering the delineated contours of the prostates in all scans of all patients. Gray value registrations that showed large differences with respect to contour registrations were detected with a χ 2

Supervised guiding long-short term memory for image caption generation based on object classes

Science.gov (United States)

Wang, Jian; Cao, Zhiguo; Xiao, Yang; Qi, Xinyuan

2018-03-01

The present models of image caption generation have the problems of image visual semantic information attenuation and errors in guidance information. In order to solve these problems, we propose a supervised guiding Long Short Term Memory model based on object classes, named S-gLSTM for short. It uses the object detection results from R-FCN as supervisory information with high confidence, and updates the guidance word set by judging whether the last output matches the supervisory information. S-gLSTM learns how to extract the current interested information from the image visual se-mantic information based on guidance word set. The interested information is fed into the S-gLSTM at each iteration as guidance information, to guide the caption generation. To acquire the text-related visual semantic information, the S-gLSTM fine-tunes the weights of the network through the back-propagation of the guiding loss. Complementing guidance information at each iteration solves the problem of visual semantic information attenuation in the traditional LSTM model. Besides, the supervised guidance information in our model can reduce the impact of the mismatched words on the caption generation. We test our model on MSCOCO2014 dataset, and obtain better performance than the state-of-the- art models.

SU-E-J-185: A Systematic Review of Breathing Guidance in Radiation Oncology and Radiology

International Nuclear Information System (INIS)

Pollock, S; Keall, P; Keall, R

2015-01-01

Purpose: The advent of image-guided radiation therapy (IGRT) has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion is the use of breathing guidance systems during imaging and treatment. A review of such research had not yet been performed, it was therefore our aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: Results of online database searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with the PRISMAStatement reporting standard (Preferred Reporting Items for Systematic reviews and Meta-Analyses) utilizing the PICOS approach (Participants, Intervention, Comparison, Outcome, Study design). Participants: Cancer patients, healthy volunteers. Intervention: Biofeedback breathing guidance systems. Comparison: No breathing guidance of the same breathing type. Outcome: Regularity of breathing signal and anatomic/tumor motion, medical image quality, radiation treatment margins and coverage, medical imaging and radiation treatment times. Study design: Quantitative and controlled prospective or retrospective trials. Results: The systematic search yielded a total of 479 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. The vast majority of investigated outcomes were significantly positively impacted by the use of breathing guidance; however, this was dependent upon the nature of the breathing guidance system and study design. In 25/27 studies significant improvements from the use of breathing guidance were observed. Conclusion: The results found here indicate that further clinical studies are warranted which quantify more comprehensively the

SU-E-J-185: A Systematic Review of Breathing Guidance in Radiation Oncology and Radiology

Energy Technology Data Exchange (ETDEWEB)

Pollock, S; Keall, P [University of Sydney, Sydney (Australia); Keall, R [Hammond Care Palliative and Supportive Care Service, Sydney, NSW (Australia)

2015-06-15

Purpose: The advent of image-guided radiation therapy (IGRT) has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion is the use of breathing guidance systems during imaging and treatment. A review of such research had not yet been performed, it was therefore our aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: Results of online database searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with the PRISMAStatement reporting standard (Preferred Reporting Items for Systematic reviews and Meta-Analyses) utilizing the PICOS approach (Participants, Intervention, Comparison, Outcome, Study design). Participants: Cancer patients, healthy volunteers. Intervention: Biofeedback breathing guidance systems. Comparison: No breathing guidance of the same breathing type. Outcome: Regularity of breathing signal and anatomic/tumor motion, medical image quality, radiation treatment margins and coverage, medical imaging and radiation treatment times. Study design: Quantitative and controlled prospective or retrospective trials. Results: The systematic search yielded a total of 479 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. The vast majority of investigated outcomes were significantly positively impacted by the use of breathing guidance; however, this was dependent upon the nature of the breathing guidance system and study design. In 25/27 studies significant improvements from the use of breathing guidance were observed. Conclusion: The results found here indicate that further clinical studies are warranted which quantify more comprehensively the

Accuracy and inter-observer variability of 3D versus 4D cone-beam CT based image-guidance in SBRT for lung tumors

International Nuclear Information System (INIS)

Sweeney, Reinhart A; Seubert, Benedikt; Stark, Silke; Homann, Vanessa; Müller, Gerd; Flentje, Michael; Guckenberger, Matthias

2012-01-01

To analyze the accuracy and inter-observer variability of image-guidance (IG) using 3D or 4D cone-beam CT (CBCT) technology in stereotactic body radiotherapy (SBRT) for lung tumors. Twenty-one consecutive patients treated with image-guided SBRT for primary and secondary lung tumors were basis for this study. A respiration correlated 4D-CT and planning contours served as reference for all IG techniques. Three IG techniques were performed independently by three radiation oncologists (ROs) and three radiotherapy technicians (RTTs). Image-guidance using respiration correlated 4D-CBCT (IG-4D) with automatic registration of the planning 4D-CT and the verification 4D-CBCT was considered gold-standard. Results were compared with two IG techniques using 3D-CBCT: 1) manual registration of the planning internal target volume (ITV) contour and the motion blurred tumor in the 3D-CBCT (IG-ITV); 2) automatic registration of the planning reference CT image and the verification 3D-CBCT (IG-3D). Image quality of 3D-CBCT and 4D-CBCT images was scored on a scale of 1–3, with 1 being best and 3 being worst quality for visual verification of the IGRT results. Image quality was scored significantly worse for 3D-CBCT compared to 4D-CBCT: the worst score of 3 was given in 19 % and 7.1 % observations, respectively. Significant differences in target localization were observed between 4D-CBCT and 3D-CBCT based IG: compared to the reference of IG-4D, tumor positions differed by 1.9 mm ± 0.9 mm (3D vector) on average using IG-ITV and by 3.6 mm ± 3.2 mm using IG-3D; results of IG-ITV were significantly closer to the reference IG-4D compared to IG-3D. Differences between the 4D-CBCT and 3D-CBCT techniques increased significantly with larger motion amplitude of the tumor; analogously, differences increased with worse 3D-CBCT image quality scores. Inter-observer variability was largest in SI direction and was significantly larger in IG using 3D-CBCT compared to 4D-CBCT: 0.6 mm versus 1.5 mm

Accuracy and inter-observer variability of 3D versus 4D cone-beam CT based image-guidance in SBRT for lung tumors

Directory of Open Access Journals (Sweden)

Sweeney Reinhart A

2012-06-01

Full Text Available Abstract Background To analyze the accuracy and inter-observer variability of image-guidance (IG using 3D or 4D cone-beam CT (CBCT technology in stereotactic body radiotherapy (SBRT for lung tumors. Materials and methods Twenty-one consecutive patients treated with image-guided SBRT for primary and secondary lung tumors were basis for this study. A respiration correlated 4D-CT and planning contours served as reference for all IG techniques. Three IG techniques were performed independently by three radiation oncologists (ROs and three radiotherapy technicians (RTTs. Image-guidance using respiration correlated 4D-CBCT (IG-4D with automatic registration of the planning 4D-CT and the verification 4D-CBCT was considered gold-standard. Results were compared with two IG techniques using 3D-CBCT: 1 manual registration of the planning internal target volume (ITV contour and the motion blurred tumor in the 3D-CBCT (IG-ITV; 2 automatic registration of the planning reference CT image and the verification 3D-CBCT (IG-3D. Image quality of 3D-CBCT and 4D-CBCT images was scored on a scale of 1–3, with 1 being best and 3 being worst quality for visual verification of the IGRT results. Results Image quality was scored significantly worse for 3D-CBCT compared to 4D-CBCT: the worst score of 3 was given in 19 % and 7.1 % observations, respectively. Significant differences in target localization were observed between 4D-CBCT and 3D-CBCT based IG: compared to the reference of IG-4D, tumor positions differed by 1.9 mm ± 0.9 mm (3D vector on average using IG-ITV and by 3.6 mm ± 3.2 mm using IG-3D; results of IG-ITV were significantly closer to the reference IG-4D compared to IG-3D. Differences between the 4D-CBCT and 3D-CBCT techniques increased significantly with larger motion amplitude of the tumor; analogously, differences increased with worse 3D-CBCT image quality scores. Inter-observer variability was largest in SI direction and was

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

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Katharine E. Alter

2017-12-01

Full Text Available Injections of botulinum neurotoxins (BoNTs are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

Image Guidance Based on Prostate Position for Prostate Cancer Proton Therapy

International Nuclear Information System (INIS)

Vargas, Carlos; Wagner, Marcus; Indelicato, Daniel; Fryer, Amber; Horne, David; Chellini, Angela; McKenzie, Craig; Lawlor, Paula; Mahajan, Chaitali; Li Zuofeng; Lin Liyong; Keole, Sameer

2008-01-01

Purpose: To determine the target coverage for proton therapy with and without image guidance and daily prebeam reorientation. Methods and Materials: A total of 207 prostate positions were analyzed for 9 prostate cancer patients treated using our low-risk prostate proton therapy protocol (University of Florida Proton Therapy Institute 001). The planning target volume was defined as the prostate plus a 5-mm axial and 8-mm superoinferior extension. The prostate was repositioned using 5- and 10-mm shifts (anteriorly, inferiorly, posteriorly, and superiorly) and for Points A-D using a combination of 10-mm multidimensional movements (anteriorly or inferiorly; posteriorly or superiorly; and left or right). The beams were then realigned using the new prostate position. The prescription dose was 78 Gray equivalent (GE) to 95% of the planning target volume. Results: For small movements in the anterior, inferior, and posterior directions within the planning target volume (≤5 mm), treatment realignment demonstrated small, but significant, improvements in the clinical target volume (CTV) coverage to the prescribed dose (78 GE). The anterior and posterior shifts also significantly increased the minimal CTV dose (Δ +1.59 GE). For prostate 10-mm movements in the inferior, posterior, and superior directions, the beam realignment produced larger and significant improvements for both the CTV V 78 (Δ +6.4%) and the CTV minimal dose (Δ +8.22 GE). For the compounded 10-mm multidimensional shifts, realignment significantly improved the CTV V 78 (Δ +11.8%) and CTV minimal dose (Δ +23.6 GE). After realignment, the CTV minimal dose was >76.6 GE (>98%) for all points (A-D). Conclusion: Proton beam realignment after target shift will enhance CTV coverage for different prostate positions

European Universities' Guidance on Research Integrity and Misconduct.

Science.gov (United States)

Aubert Bonn, Noémie; Godecharle, Simon; Dierickx, Kris

2017-02-01

Research integrity is imperative to good science. Nonetheless, many countries and institutions develop their own integrity guidance, thereby risking incompatibilities with guidance of collaborating institutions. We retrieved guidance for academic integrity and misconduct of 18 universities from 10 European countries and investigated accessibility, general content, principles endorsed, and definitions of misconduct. Accessibility and content differ substantially between institutions. There are general trends of common principles of integrity and definitions of misconduct, yet differences remain. Parallel with previous research, we distinguish different approaches in integrity guidance; one emphasizes broad values of integrity, and the other details negative behaviors of misconduct. We propose that a balance between both approaches is necessary to preserve trust, meaning, and realism of guidance on research integrity.

The effect of family therapy on the changes in the severity of on-line game play and brain activity in adolescents with on-line game addiction

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Han, Doug Hyun; Kim, Sun Mi; Lee, Young Sik; Renshaw, Perry F.

2015-01-01

We evaluated whether a brief 3-week family therapy intervention would change patterns of brain activation in response to affection and gaming cues in adolescents from dysfunctional families who met criteria for on-line game addiction. Fifteen adolescents with on-line game addiction and fifteen adolescents without problematic on-line game play and an intact family structure were recruited. Over 3 weeks, families were asked to carry out homework assignments focused on increasing family cohesion for more than 1 hour/day and 4 days/week. Before therapy, adolescents with on-line game addiction demonstrated decreased activity as measured by functional magnetic resonance imaging (fMRI) within the caudate, middle temporal gyrus, and occipital lobe in response to images depicting parental affection and increased activity of the middle frontal and inferior parietal in response scenes from on-line games, relative to healthy comparison subjects. Improvement in perceived family cohesion following 3 weeks of treatment was associated with an increase in the activity of the caudate nucleus in response to affection stimuli and was inversely correlated with changes in on-line game playing time. With evidence of brain activation changes in response to on-line game playing cues and images depicting parental love, the present findings suggest that family cohesion may be an important factor in the treatment of problematic on-line game playing. PMID:22698763

Visual Perception-Based Statistical Modeling of Complex Grain Image for Product Quality Monitoring and Supervision on Assembly Production Line.

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Jinping Liu

Full Text Available Computer vision as a fast, low-cost, noncontact, and online monitoring technology has been an important tool to inspect product quality, particularly on a large-scale assembly production line. However, the current industrial vision system is far from satisfactory in the intelligent perception of complex grain images, comprising a large number of local homogeneous fragmentations or patches without distinct foreground and background. We attempt to solve this problem based on the statistical modeling of spatial structures of grain images. We present a physical explanation in advance to indicate that the spatial structures of the complex grain images are subject to a representative Weibull distribution according to the theory of sequential fragmentation, which is well known in the continued comminution of ore grinding. To delineate the spatial structure of the grain image, we present a method of multiscale and omnidirectional Gaussian derivative filtering. Then, a product quality classifier based on sparse multikernel-least squares support vector machine is proposed to solve the low-confidence classification problem of imbalanced data distribution. The proposed method is applied on the assembly line of a food-processing enterprise to classify (or identify automatically the production quality of rice. The experiments on the real application case, compared with the commonly used methods, illustrate the validity of our method.

Visual Perception-Based Statistical Modeling of Complex Grain Image for Product Quality Monitoring and Supervision on Assembly Production Line.

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Liu, Jinping; Tang, Zhaohui; Zhang, Jin; Chen, Qing; Xu, Pengfei; Liu, Wenzhong

2016-01-01

Computer vision as a fast, low-cost, noncontact, and online monitoring technology has been an important tool to inspect product quality, particularly on a large-scale assembly production line. However, the current industrial vision system is far from satisfactory in the intelligent perception of complex grain images, comprising a large number of local homogeneous fragmentations or patches without distinct foreground and background. We attempt to solve this problem based on the statistical modeling of spatial structures of grain images. We present a physical explanation in advance to indicate that the spatial structures of the complex grain images are subject to a representative Weibull distribution according to the theory of sequential fragmentation, which is well known in the continued comminution of ore grinding. To delineate the spatial structure of the grain image, we present a method of multiscale and omnidirectional Gaussian derivative filtering. Then, a product quality classifier based on sparse multikernel-least squares support vector machine is proposed to solve the low-confidence classification problem of imbalanced data distribution. The proposed method is applied on the assembly line of a food-processing enterprise to classify (or identify) automatically the production quality of rice. The experiments on the real application case, compared with the commonly used methods, illustrate the validity of our method.

On the design of fuzzified trajectory shaping guidance law.

Science.gov (United States)

Lin, Chun-Liang; Lin, Yu-Ping; Chen, Kai-Ming

2009-04-01

Midcourse guidance is commonly designed to save as much energy as possible so that the missile's final speed can be maximized while entering the homing stage. For this purpose, a competitive guidance design should be able to generate an admissible flight trajectory as to bring the interceptor to a superior altitude for a favorable target engagement. In this paper, a new adaptive trajectory shaping guidance scheme based on the adaptive fuzzy inference system, which is capable of generating a variety of trajectories for efficient target interception, is presented. The guidance law is developed with the aim of saving the interceptor's energy conservation while improving performance robustness. Applications of the presented approach have included a variety of mission oriented guidance, such as cruise missile guidance, anti-ballistic missile guidance, etc.

RMP Guidance for Chemical Distributors - Appendix D: OSHA Guidance on PSM

Science.gov (United States)

Guidance on the Process Safety Management standard says information (including MSDS) about chemicals, including process intermediates, must enable accurate assessment of fire/explosion characteristics, reactivity hazards, and corrosing/erosion effects.

Prototype volumetric ultrasound tomography image guidance system for prone stereotactic partial breast irradiation: proof-of-concept

Science.gov (United States)

Chiu, Tsuicheng D.; Parsons, David; Zhang, Yue; Hrycushko, Brian; Zhao, Bo; Chopra, Rajiv; Kim, Nathan; Spangler, Ann; Rahimi, Asal; Timmerman, Robert; Jiang, Steve B.; Lu, Weiguo; Gu, Xuejun

2018-03-01

Accurate dose delivery in stereotactic partial breast irradiation (S-PBI) is challenging because of the target position uncertainty caused by breast deformation, the target volume changes caused by lumpectomy cavity shrinkage, and the target delineation uncertainty on simulation computed tomography (CT) images caused by poor soft tissue contrast. We have developed a volumetric ultrasound tomography (UST) image guidance system for prone position S-PBI. The system is composed of a novel 3D printed rotation water tank, a patient-specific resin breast immobilization cup, and a 1D array ultrasound transducer. Coronal 2D US images were acquired in 5° increments over a 360° range, and planes were acquired every 2 mm in elevation. A super-compounding technique was used to reconstruct the image volume. The image quality of UST was evaluated with a BB-1 breast phantom and BioZorb surgical marker, and the results revealed that UST offered better soft tissue contrast than CT and similar image quality to MR. In the evaluated plane, the size and location of five embedded objects were measured and compared to MR, which is considered as the ground truth. Objects’ diameters and the distances between objects in UST differ by approximately 1 to 2 mm from those in MR, which showed that UST offers the image quality required for S-PBI. In future work we will develop a robotic system that will be ultimately implemented in the clinic.

Guidance of attention by information held in working memory.

Science.gov (United States)

Calleja, Marissa Ortiz; Rich, Anina N

2013-05-01

Information held in working memory (WM) can guide attention during visual search. The authors of recent studies have interpreted the effect of holding verbal labels in WM as guidance of visual attention by semantic information. In a series of experiments, we tested how attention is influenced by visual features versus category-level information about complex objects held in WM. Participants either memorized an object's image or its category. While holding this information in memory, they searched for a target in a four-object search display. On exact-match trials, the memorized item reappeared as a distractor in the search display. On category-match trials, another exemplar of the memorized item appeared as a distractor. On neutral trials, none of the distractors were related to the memorized object. We found attentional guidance in visual search on both exact-match and category-match trials in Experiment 1, in which the exemplars were visually similar. When we controlled for visual similarity among the exemplars by using four possible exemplars (Exp. 2) or by using two exemplars rated as being visually dissimilar (Exp. 3), we found attentional guidance only on exact-match trials when participants memorized the object's image. The same pattern of results held when the target was invariant (Exps. 2-3) and when the target was defined semantically and varied in visual features (Exp. 4). The findings of these experiments suggest that attentional guidance by WM requires active visual information.

Rapidly-steered single-element ultrasound for real-time volumetric imaging and guidance

Science.gov (United States)

Stauber, Mark; Western, Craig; Solek, Roman; Salisbury, Kenneth; Hristov, Dmitre; Schlosser, Jeffrey

2016-03-01

Volumetric ultrasound (US) imaging has the potential to provide real-time anatomical imaging with high soft-tissue contrast in a variety of diagnostic and therapeutic guidance applications. However, existing volumetric US machines utilize "wobbling" linear phased array or matrix phased array transducers which are costly to manufacture and necessitate bulky external processing units. To drastically reduce cost, improve portability, and reduce footprint, we propose a rapidly-steered single-element volumetric US imaging system. In this paper we explore the feasibility of this system with a proof-of-concept single-element volumetric US imaging device. The device uses a multi-directional raster-scan technique to generate a series of two-dimensional (2D) slices that were reconstructed into three-dimensional (3D) volumes. At 15 cm depth, 90° lateral field of view (FOV), and 20° elevation FOV, the device produced 20-slice volumes at a rate of 0.8 Hz. Imaging performance was evaluated using an US phantom. Spatial resolution was 2.0 mm, 4.7 mm, and 5.0 mm in the axial, lateral, and elevational directions at 7.5 cm. Relative motion of phantom targets were automatically tracked within US volumes with a mean error of -0.3+/-0.3 mm, -0.3+/-0.3 mm, and -0.1+/-0.5 mm in the axial, lateral, and elevational directions, respectively. The device exhibited a mean spatial distortion error of 0.3+/-0.9 mm, 0.4+/-0.7 mm, and -0.3+/-1.9 in the axial, lateral, and elevational directions. With a production cost near $1000, the performance characteristics of the proposed system make it an ideal candidate for diagnostic and image-guided therapy applications where form factor and low cost are paramount.

Digital twin image elimination in soft x-ray in-line holography

International Nuclear Information System (INIS)

Koren, G.; Joyeux, D.

1993-01-01

In-line holography is attractive for X-ray microscopy due to its recording simplicity. A drawback of this method is the superposition of the virtual and real images, in which structures and details can be modified or lost. This superposition effectively limits the application of in-line holography to X-ray microscopy. The authors present an iterative constrained algorithm for twin image elimination from Gabor holograms of finite support objects. It is based in the different spatial extent of both images, together with a finite support constraint. The conditions under which the algorithm is applicable will be presented, together with an alternative Monte Carlo method for holograms of complex objects recorded in the shadow region

Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS).

Science.gov (United States)

Eichhorn, Klaus Wolfgang; Westphal, Ralf; Rilk, Markus; Last, Carsten; Bootz, Friedrich; Wahl, Friedrich; Jakob, Mark; Send, Thorsten

2017-10-01

Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images. We collected the pose data (position and orientation) of the rigid 0° endoscope and all the instruments used in 16 FESS procedures with manual endoscope guidance as well as robot-assisted endoscope guidance. In combination with the DICOM CT data, we tracked the endoscope poses and workspaces using self-developed tracking markers. All surgeries were performed once with the robot and once with the surgeon holding the endoscope. Looking at the durations required, we observed a decrease in the operating time because one surgeon doing all the procedures and so a learning curve occurred what we expected. The visual inspection of the specimens showed no damages to any of the structures outside the paranasal sinuses. Robot-assisted endoscope guidance in sinus surgery is possible. Further CT data, however, are desirable for the surgical analysis of a tracker-based navigation within the anatomic borders. Our marker-based tracking of the endoscope as well as the instruments makes an automated endoscope guidance feasible. On the subjective side, we see that RASS brings a relief for the surgeon.

Nigerian Journal of Guidance and Counselling

African Journals Online (AJOL)

The Nigerian Journal of Guidance and Counselling. ... Journal Homepage Image ... by the Department of Counsellor Education, University of Ilorin, Ilorin, Nigeria. ... Awareness and use of Meseron therapy among clinical psychologists in ...

Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

Directory of Open Access Journals (Sweden)

Young Ho Park

2012-10-01

Full Text Available On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger-vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger-vein recognition is advantageous in that it involves the use of inexpensive and small devices that are difficult to counterfeit. In general, finger-vein recognition systems capture images by using near infrared (NIR illumination in conjunction with a camera. However, such systems can face operational difficulties, since the scattering of light from the skin can make capturing a clear image difficult. To solve this problem, we proposed new image quality enhancement method that measures the direction and thickness of vein lines. This effort represents novel research in four respects. First, since vein lines are detected in input images based on eight directional profiles of a grey image instead of binarized images, the detection error owing to the non-uniform illumination of the finger area can be reduced. Second, our method adaptively determines a Gabor filter for the optimal direction and width on the basis of the estimated direction and thickness of a detected vein line. Third, by applying this optimized Gabor filter, a clear vein image can be obtained. Finally, the further processing of the morphological operation is applied in the Gabor filtered image and the resulting image is combined with the original one, through which finger-vein image of a higher quality is obtained. Experimental results from application of our proposed image enhancement method show that the equal error rate (EER of finger-vein recognition decreases to approximately 0.4% in the case of a local binary pattern-based recognition and to approximately 0.3% in the case of a wavelet transform

WODA Technical Guidance on Underwater Sound from Dredging.

Science.gov (United States)

Thomsen, Frank; Borsani, Fabrizio; Clarke, Douglas; de Jong, Christ; de Wit, Pim; Goethals, Fredrik; Holtkamp, Martine; Martin, Elena San; Spadaro, Philip; van Raalte, Gerard; Victor, George Yesu Vedha; Jensen, Anders

2016-01-01

The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic biota and advice on underwater sound monitoring procedures. The paper follows a risk-based approach and provides guidance for standardization of acoustic terminology and methods for data collection and analysis. Furthermore, the literature on dredging-related sounds and the effects of dredging sounds on marine life is surveyed and guidance on the management of dredging-related sound risks is provided.

Development of a SEM-based low-energy in-line electron holography microscope for individual particle imaging.

Science.gov (United States)

Adaniya, Hidehito; Cheung, Martin; Cassidy, Cathal; Yamashita, Masao; Shintake, Tsumoru

2018-05-01

A new SEM-based in-line electron holography microscope has been under development. The microscope utilizes conventional SEM and BF-STEM functionality to allow for rapid searching of the specimen of interest, seamless interchange between SEM, BF-STEM and holographic imaging modes, and makes use of coherent low-energy in-line electron holography to obtain low-dose, high-contrast images of light element materials. We report here an overview of the instrumentation and first experimental results on gold nano-particles and carbon nano-fibers for system performance tests. Reconstructed images obtained from the holographic imaging mode of the new microscope show substantial image contrast and resolution compared to those acquired by SEM and BF-STEM modes, demonstrating the feasibility of high-contrast imaging via low-energy in-line electron holography. The prospect of utilizing the new microscope to image purified biological specimens at the individual particle level is discussed and electron optical issues and challenges to further improve resolution and contrast are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

FogBank: a single cell segmentation across multiple cell lines and image modalities.

Science.gov (United States)

Chalfoun, Joe; Majurski, Michael; Dima, Alden; Stuelten, Christina; Peskin, Adele; Brady, Mary

2014-12-30

Many cell lines currently used in medical research, such as cancer cells or stem cells, grow in confluent sheets or colonies. The biology of individual cells provide valuable information, thus the separation of touching cells in these microscopy images is critical for counting, identification and measurement of individual cells. Over-segmentation of single cells continues to be a major problem for methods based on morphological watershed due to the high level of noise in microscopy cell images. There is a need for a new segmentation method that is robust over a wide variety of biological images and can accurately separate individual cells even in challenging datasets such as confluent sheets or colonies. We present a new automated segmentation method called FogBank that accurately separates cells when confluent and touching each other. This technique is successfully applied to phase contrast, bright field, fluorescence microscopy and binary images. The method is based on morphological watershed principles with two new features to improve accuracy and minimize over-segmentation. First, FogBank uses histogram binning to quantize pixel intensities which minimizes the image noise that causes over-segmentation. Second, FogBank uses a geodesic distance mask derived from raw images to detect the shapes of individual cells, in contrast to the more linear cell edges that other watershed-like algorithms produce. We evaluated the segmentation accuracy against manually segmented datasets using two metrics. FogBank achieved segmentation accuracy on the order of 0.75 (1 being a perfect match). We compared our method with other available segmentation techniques in term of achieved performance over the reference data sets. FogBank outperformed all related algorithms. The accuracy has also been visually verified on data sets with 14 cell lines across 3 imaging modalities leading to 876 segmentation evaluation images. FogBank produces single cell segmentation from confluent cell

Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid.

Science.gov (United States)

Stankovic, Uros; van Herk, Marcel; Ploeger, Lennert S; Sonke, Jan-Jakob

2014-06-01

Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different acquisition

Development of patient-controlled respiratory gating system based on visual guidance for magnetic-resonance image-guided radiation therapy.

Science.gov (United States)

Kim, Jung-In; Lee, Hanyoung; Wu, Hong-Gyun; Chie, Eui Kyu; Kang, Hyun-Cheol; Park, Jong Min

2017-09-01

The aim of this study is to develop a visual guidance patient-controlled (VG-PC) respiratory gating system for respiratory-gated magnetic-resonance image-guided radiation therapy (MR-IGRT) and to evaluate the performance of the developed system. The near-real-time cine planar MR image of a patient acquired during treatment was transmitted to a beam projector in the treatment room through an optical fiber cable. The beam projector projected the cine MR images inside the bore of the ViewRay system in order to be visible to a patient during treatment. With this visual information, patients voluntarily controlled their respiration to put the target volume into the gating boundary (gating window). The effect of the presence of the beam projector in the treatment room on the image quality of the MRI was investigated by evaluating the signal-to-noise ratio (SNR), uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity with the VG-PC gating system. To evaluate the performance of the developed system, we applied the VG-PC gating system to a total of seven patients; six patients received stereotactic ablative radiotherapy (SABR) and one patient received conventional fractionated radiation therapy. The projected cine MR images were visible even when the room light was on. No image data loss or additional time delay during delivery of image data were observed. Every indicator representing MRI quality, including SNR, uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity exhibited values higher than the tolerance levels of the manufacturer with the VG-PC gating system; therefore, the presence of the VG-PC gating system in the treatment room did not degrade the MR image quality. The average beam-off times due to respiratory gating with and without the VG-PC gating system were 830.3 ± 278.2 s and 1264.2 ± 302.1 s respectively (P = 0.005). Consequently, the total treatment times excluding

A novel line segment detection algorithm based on graph search

Science.gov (United States)

Zhao, Hong-dan; Liu, Guo-ying; Song, Xu

2018-02-01

To overcome the problem of extracting line segment from an image, a method of line segment detection was proposed based on the graph search algorithm. After obtaining the edge detection result of the image, the candidate straight line segments are obtained in four directions. For the candidate straight line segments, their adjacency relationships are depicted by a graph model, based on which the depth-first search algorithm is employed to determine how many adjacent line segments need to be merged. Finally we use the least squares method to fit the detected straight lines. The comparative experimental results verify that the proposed algorithm has achieved better results than the line segment detector (LSD).

Cone beam computed tomography and its image guidance technology during percutaneous nucleoplasty procedures at L5/S1 lumbar level

Energy Technology Data Exchange (ETDEWEB)

Ierardi, Anna Maria; Piacentino, Filippo; Giorlando, Francesca [University of Insubria, Unit of Interventional Radiology, Department of Radiology, Varese (Italy); Magenta Biasina, Alberto; Carrafiello, Gianpaolo [University of Milan, San Paolo Hospital, Department of Diagnostic and Interventional Radiology, Milan (Italy); Bacuzzi, Alessandro [University of Insubria, Anaesthesia and Palliative Care, Varese (Italy); Novario, Raffaele [University of Insubria, Medical Physics Department, Varese (Italy)

2016-12-15

To demonstrate the feasibility of percutaneous nucleoplasty procedures at L5/S1 level using cone beam CT (CBCT) and its associated image guidance technology for the treatment of lumbar disc herniation (LDH). We retrospectively reviewed 25 cases (20 men, 5 women) of LDH at L5/S1 levels. CBCT as guidance imaging was chosen after a first unsuccessful fluoroscopy attempt that was related to complex anatomy (n = 15), rapid pathological changes due to degenerative diseases (n = 7) or both (n = 3). Technical success, defined as correct needle positioning in the target LDH, and safety were evaluated; overall procedure time and radiation dose were registered. A visual analog scale (VAS) was used to evaluate pain and discomfort pre-intervention after 1 week and 1, 3, and 6 months after the procedure. Technical success was 100 %; using CBCT as guidance imaging the needle was correctly positioned at the first attempt in 20 out of 25 patients. Neither major nor minor complications were registered during or after the procedure. The average procedure time was 11 min and 56 s (range, 9-15 min), whereas mean procedural radiation dose was 46.25 Gy.cm{sup 2} (range 38.10-52.84 Gy.cm{sup 2}), and mean fluoroscopy time was 5 min 34 s (range 3 min 40 s to 6 min 55 s). The VAS pain score decreased significantly from 7.6 preoperatively to 3.9 at 1 week, 2.8 at 1 month, 2.1 at 3 months, and 1.6 at 6 months postoperatively. CBCT-guided percutaneous nucleoplasty is a highly effective technique for LDH with acceptable procedure time and radiation dose. (orig.)

Guidance theory and practice : the status of career exploration

OpenAIRE

Taveira, Maria do Céu; Rodríguez Moreno, Maria Luísa

2003-01-01

Career intervention can be designed to enhance constructive attitudes, emotions and behaviours that will improve clients’ career attainment. In this sense, mobilisation of career exploration constitutes one of the most important tasks of career counsellors, particularly with emphasis in developmental career guidance models, first developed in the 1950s. The authors present a brief review of career exploration conceptualisation and empirical research lines. The implications for career guidance...

Thermographic Sensing For On-Line Industrial Control

Science.gov (United States)

Holmsten, Dag

1986-10-01

It is today's emergence of thermoelectrically cooled, highly accurate infrared linescanners and imaging systems that has definitely made on-line Infraread Thermography (IRT) possible. Specifically designed for continuous use, these scanners are equipped with dedicated software capable of monitoring and controlling highly complex thermodynamic situations. This paper will outline some possible implications of using IRT on-line by describing some uses of this technology in the steel-making (hot rolling) and automotive industries (machine-vision). A warning is also expressed that IRT technology not originally designed for automated applications e.g. high resolution, imaging systems, should not be directly applied to an on-line measurement situation without having its measurement resolution, accuracy and especially its repeatability, reliably proven. Some suitable testing procedures are briefly outlined at the end of the paper.

On-line implant reconstruction in HDR brachytherapy

International Nuclear Information System (INIS)

Kolkman-Deurloo, Inger-Karine K.; Kruijf, Wilhelmus J.M. de; Levendag, Peter C.

2006-01-01

Background and purpose: To evaluate the accuracy of on-line planning in an Integrated Brachytherapy Unit (IBU) using dedicated image distortion correction algorithms, correcting the geometric distortion and magnetic distortion separately, and to determine the effect of the reconstruction accuracy on clinical treatment plans in terms of deviations in treatment time and dose. Patients and methods: The reconstruction accuracy has been measured using 20 markers, positioned at well known locations in a QA phantom. Treatment plans of two phantoms representing clinical implant geometries, have been compared with reference plans to determine the effect of the reconstruction accuracy on the treatment plan. Before clinical introduction, treatment plans of three representative patients, based on on-line reconstruction, have been compared with reference plans. Results: The average reconstruction error for 10 in. images reduces from -0.6 mm (range -2.6 to +1.0 mm) to -0.2 mm (range -1.2 to +0.6 mm) after image distortion correction and for 15 in. images from 0.8 mm (range -0.5 to +3.0 mm) to 0.0 mm (range -0.8 to +0.8 mm). The error in case of eccentric positioning of the phantom, i.e. 0.8 mm (range -1.0 to +3.3 mm), reduces to 0.1 mm (range -0.5 to +0.9 mm). Correction of the image distortions reduces the deviation in the calculated treatment time of maximally 2.7% to less than 0.8% in case of eccentrically positioned clinical phantoms. The deviation in the treatment time or reference dose in the plans based on on-line reconstruction with image distortion correction of the three patient examples is smaller than 0.3%. Conclusions: Accurate on-line implant reconstruction using the IBU localiser and dedicated correction algorithms separating the geometric distortion and the magnetic distortion is possible. The results fulfill the minimum requirements as imposed by the Netherlands Commission on Radiation Dosimetry (NCS) without limitations regarding the usable range of the field

Guidance on Dependence Assessment in SPAR-H

Energy Technology Data Exchange (ETDEWEB)

April M. Whaley

2012-06-01

As part of the effort to develop the SPAR-H user guidance, particular attention was paid to the assessment of dependence in order to address user questions about proper application of dependence. This paper presents a discussion of dependence from a psychological perspective and provides guidance on applying this information during the qualitative analysis of dependence to ensure more realistic and appropriate dependence assessments with the SPAR-H method. While this guidance was developed with SPAR-H in mind, it may be informative to other human reliability analysis methods that also use a THERP-based dependence approach, particularly if applied at the human failure event level.

78 FR 49782 - Interim Staff Guidance on Changes During Construction

Science.gov (United States)

2013-08-15

... Construction AGENCY: Nuclear Regulatory Commission. ACTION: Draft interim staff guidance; request for comment... During Construction.'' This ISG provides guidance to the NRC staff on the Preliminary Amendment Request...-ISG-025 ``Interim Staff Guidance on Changes during Construction under 10 CFR Part 52'' is available...

Aerial image geolocalization by matching its line structure with route map

Science.gov (United States)

Kunina, I. A.; Terekhin, A. P.; Khanipov, T. M.; Kuznetsova, E. G.; Nikolaev, D. P.

2017-03-01

The classic way of aerial photographs geolocation is to bind their local coordinates to a geographic coordinate system using GPS and IMU data. At the same time the possibility of geolocation in a jammed navigation field is also of interest for practical purposes. In this paper we consider one approach to visual localization relatively to a vector road map without GPS. We suggest a geolocalization algorithm which detects image line segments and looks for a geometrical transformation which provides the best mapping between the obtained segments set and line segments in the road map. We consider IMU and altimeter data still known which allows to work with orthorectified images. The problem is hence reduced to a search for a transformation which contains an arbitrary shift and bounded rotation and scaling relatively to the vector map. These parameters are estimated using RANSAC by matching straight line segments from the image to vector map segments. We also investigate how the proposed algorithm's stability is influenced by segment coordinates (two spatial and one angular).

Multimodal system for the planning and guidance of bronchoscopy

Science.gov (United States)

Higgins, William E.; Cheirsilp, Ronnarit; Zang, Xiaonan; Byrnes, Patrick

2015-03-01

Many technical innovations in multimodal radiologic imaging and bronchoscopy have emerged recently in the effort against lung cancer. Modern X-ray computed-tomography (CT) scanners provide three-dimensional (3D) high-resolution chest images, positron emission tomography (PET) scanners give complementary molecular imaging data, and new integrated PET/CT scanners combine the strengths of both modalities. State-of-the-art bronchoscopes permit minimally invasive tissue sampling, with vivid endobronchial video enabling navigation deep into the airway-tree periphery, while complementary endobronchial ultrasound (EBUS) reveals local views of anatomical structures outside the airways. In addition, image-guided intervention (IGI) systems have proven their utility for CT-based planning and guidance of bronchoscopy. Unfortunately, no IGI system exists that integrates all sources effectively through the complete lung-cancer staging work flow. This paper presents a prototype of a computer-based multimodal IGI system that strives to fill this need. The system combines a wide range of automatic and semi-automatic image-processing tools for multimodal data fusion and procedure planning. It also provides a flexible graphical user interface for follow-on guidance of bronchoscopy/EBUS. Human-study results demonstrate the system's potential.

Visual guidance of mobile platforms

Science.gov (United States)

Blissett, Rodney J.

1993-12-01

Two systems are described and results presented demonstrating aspects of real-time visual guidance of autonomous mobile platforms. The first approach incorporates prior knowledge in the form of rigid geometrical models linking visual references within the environment. The second approach is based on a continuous synthesis of information extracted from image tokens to generate a coarse-grained world model, from which potential obstacles are inferred. The use of these techniques in workplace applications is discussed.

Using photoshop filters to create anatomic line-art medical images.

Science.gov (United States)

Kirsch, Jacobo; Geller, Brian S

2006-08-01

There are multiple ways to obtain anatomic drawings suitable for publication or presentations. This article demonstrates how to use Photoshop to alter digital radiologic images to create line-art illustrations in a quick and easy way. We present two simple to use methods; however, not every image can adequately be transformed and personal preferences and specific changes need to be applied to each image to obtain the desired result. There are multiple ways to obtain anatomic drawings suitable for publication or to prepare presentations. Medical illustrators have always played a major role in the radiology and medical education process. Whether used to teach a complex surgical or radiologic procedure, to define typical or atypical patterns of the spread of disease, or to illustrate normal or aberrant anatomy, medical illustration significantly affects learning (). However, if you are not an accomplished illustrator, the alternatives can be expensive (contacting a professional medical illustrator or buying an already existing stock of digital images) or simply not necessarily applicable to what you are trying to communicate. The purpose of this article is to demonstrate how using Photoshop (Adobe Systems, San Jose, CA) to alter digital radiologic images we can create line-art illustrations in a quick, inexpensive, and easy way in preparation for electronic presentations and publication.

Hollow-cathode lamps as optical frequency standards: the influence of optical imaging on the line-strength ratios

Science.gov (United States)

Huke, Philipp; Tal-Or, Lev; Sarmiento, Luis Fernando; Reiners, Ansgar

2016-07-01

Hollow cathode discharge lamps (HCLs) have been successfully used in recent years as calibration sources of optical astronomical spectrographs. The numerous narrow metal lines have stable wavelengths, which makes them well suited for m/s calibration accuracy of high-resolution spectrographs, while the buffer-gas lines are less stable and less useful. Accordingly, an important property is the metal-to-gas line-strength ratio (Rmetal/gas). Processes inside the lamp cause the light to be emitted from different regions between the cathode and the anode leaing to the emission of different beams with different values of Rmetal/gas. We used commercially- available HCLs to measure and characterize these beams with respect to their spatial distribution, their angle of propagation relative to the optical axis, and their values of Rmetal/gas. We conclude that a good imaging of an HCL into a fiber-fed spectrograph would consist of an aperture close to its front window in order to filter out the parts of the beam with low Rmetal/gas, and of a lens to collimate the important central beam. We show that Rmetal/gas can be further improved with only minor adjustments of the imaging parameters, and that the imaging scheme that yields the highest Rmetal/gas does not necessarily provide the highest flux.

Target volume geometric change and/or deviation from the cranium during fractionated stereotactic radiotherapy for brain metastases: potential pitfalls in image guidance based on bony anatomy alignment.

Science.gov (United States)

Ohtakara, Kazuhiro; Hoshi, Hiroaki

2014-12-01

This study sought to evaluate the potential geometrical change and/or displacement of the target relative to the cranium during fractionated stereotactic radiotherapy (FSRT) for treating newly developed brain metastases. For 16 patients with 21 lesions treated with image-guided frameless FSRT in 5 or 10 fractions using a 6-degree-of-freedom image guidance system-integrated platform, the unenhanced computed tomography or T2-weighted magnetic resonance images acquired until the completion of FSRT were fused to the planning image datasets for comparison. Significant change was defined as ≥3-mm change in the tumour diameter or displacement of the tumour centroid. FSRT was started 1 day after planning image acquisition. Tumour shrinkage, deviation and both were observed in 2, 1 and 1 of the 21 lesions, respectively, over a period of 7-13 days. Tumour shrinkage or deviation resulted in an increase or decrease in the marginal dose to the tumour, respectively, and a substantial increase in the irradiated volume for the surrounding tissue irrespective of the pattern of alteration. No obvious differences in the clinical and treatment characteristics were noted among the populations with or without significant changes in tumour volume or position. Target deformity and/or deviation can unexpectedly occur even during relatively short-course FSRT, inevitably leading to a gradual discrepancy between the planned and actually delivered doses to the tumour and surrounding tissue. To appropriately weigh the treatment outcome against the planned dose distribution, target deformity and/or deviation should also be considered in addition to the immobilisation accuracy, as image guidance with bony anatomy alignment does not necessarily guarantee accurate target localisation until completion of FSRT. © 2014 The Royal Australian and New Zealand College of Radiologists.

Determination of line edge roughness in low dose top-down scanning electron microscopy images

Science.gov (United States)

Verduin, T.; Kruit, P.; Hagen, C. W.

2014-04-01

We investigated off-line metrology for LER determination in low-dose SEM images to reduce the acquisition time and the risk of shrinkage. Our first attempts are based on filtering noisy (experimental) SEM images and use peak detection to measure the edge displacements and calculating the discrete PSD. However, the result of the filtering is that the power spectrum of the filter leaks into the PSD. So it is better to avoid a filter at all. We subsequently developed a method to detect edge displacements without the use of a filter. This method considers the signal profile of a SEM by integrating an experimental image of lines in the direction of the edges. The signal profile of an isolated edge is modeled as two merged Gaussians. This signal profile is then fitted against the raw (unfiltered) data of the edge pattern using an interior trust-region-reflective minimization procedure. This gives the edge displacements without the use of a filter and a filter-free version of the discrete PSD is obtained. The determination of edge displacements without the use of a filter, enables us to study how much noise is acceptable and still determine LER. To answer this question we generate random lines using the model of Palasantzas and the algorithm of Thorsos. This gives random generated edge displacements for typical values of experimental lines for the parameters of the model: 2 μm long lines (256 pixels), a correlation length ξ of 25 nm and a roughness exponent of 0.75. A noise-free top-down SEM-like image of lines is created by shifting the profile signal according to the random generated edge displacements. The image is further processed by adding Poisson-distributed noise. We consider three noise cases where the average electron density is about 2, 20 and 200 electrons per pixel. This corresponds to a charge density of (in respective order) 10 μC/cm2, 100 μC/cm2 and 1000 μC/cm2. The edge displacements of the random generated images are determined using our new

Breathing guidance in radiation oncology and radiology: A systematic review of patient and healthy volunteer studies

International Nuclear Information System (INIS)

Pollock, Sean; Keall, Paul; Keall, Robyn

2015-01-01

Purpose: The advent of image-guided radiation therapy has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion irregularities is the use of breathing guidance systems during imaging and treatment. These systems aim to facilitate regular respiratory motion which in turn improves image quality and radiation treatment accuracy. A review of such research has yet to be performed; it was therefore their aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: From August 1–14, 2014, the following online databases were searched: Medline, Embase, PubMed, and Web of Science. Results of these searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with preferred reporting items for systematic reviews and meta-analyses. Reference lists of included articles, and repeat authors of included articles, were hand-searched. Results: The systematic search yielded a total of 480 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. These 27 articles detailed the intervention of breathing guidance strategies in controlled studies assessing its impact on such outcomes as breathing regularity, image quality, target coverage, and treatment margins, recruiting either healthy adult volunteers or patients with thoracic or abdominal lesions. In 21/27 studies, significant (p < 0.05) improvements from the use of breathing guidance were observed. Conclusions: There is a trend toward the number of breathing guidance studies increasing with time, indicating a growing clinical interest. The results found here indicate that further clinical studies are warranted that quantify the

Breathing guidance in radiation oncology and radiology: A systematic review of patient and healthy volunteer studies

Energy Technology Data Exchange (ETDEWEB)

Pollock, Sean, E-mail: sean.pollock@sydney.edu.au; Keall, Paul [Radiation Physics Laboratory, University of Sydney, Sydney 2050 (Australia); Keall, Robyn [Central School of Medicine, University of Sydney, Sydney 2050, Australia and Hammond Care, Palliative Care and Supportive Care Service, Greenwich 2065 (Australia)

2015-09-15

Purpose: The advent of image-guided radiation therapy has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion irregularities is the use of breathing guidance systems during imaging and treatment. These systems aim to facilitate regular respiratory motion which in turn improves image quality and radiation treatment accuracy. A review of such research has yet to be performed; it was therefore their aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: From August 1–14, 2014, the following online databases were searched: Medline, Embase, PubMed, and Web of Science. Results of these searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with preferred reporting items for systematic reviews and meta-analyses. Reference lists of included articles, and repeat authors of included articles, were hand-searched. Results: The systematic search yielded a total of 480 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. These 27 articles detailed the intervention of breathing guidance strategies in controlled studies assessing its impact on such outcomes as breathing regularity, image quality, target coverage, and treatment margins, recruiting either healthy adult volunteers or patients with thoracic or abdominal lesions. In 21/27 studies, significant (p < 0.05) improvements from the use of breathing guidance were observed. Conclusions: There is a trend toward the number of breathing guidance studies increasing with time, indicating a growing clinical interest. The results found here indicate that further clinical studies are warranted that quantify the

Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

International Nuclear Information System (INIS)

Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob

2014-01-01

Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

On-line, continuous monitoring in solar cell and fuel cell manufacturing using spectral reflectance imaging

Energy Technology Data Exchange (ETDEWEB)

Sopori, Bhushan; Rupnowski, Przemyslaw; Ulsh, Michael

2016-01-12

A monitoring system 100 comprising a material transport system 104 providing for the transportation of a substantially planar material 102, 107 through the monitoring zone 103 of the monitoring system 100. The system 100 also includes a line camera 106 positioned to obtain multiple line images across a width of the material 102, 107 as it is transported through the monitoring zone 103. The system 100 further includes an illumination source 108 providing for the illumination of the material 102, 107 transported through the monitoring zone 103 such that light reflected in a direction normal to the substantially planar surface of the material 102, 107 is detected by the line camera 106. A data processing system 110 is also provided in digital communication with the line camera 106. The data processing system 110 is configured to receive data output from the line camera 106 and further configured to calculate and provide substantially contemporaneous information relating to a quality parameter of the material 102, 107. Also disclosed are methods of monitoring a quality parameter of a material.

International Conference on Harmonisation; guidance on Q10 Pharmaceutical Quality System; availability. Notice.

Science.gov (United States)

2009-04-08

The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "Q10 Pharmaceutical Quality System." The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance describes a model for an effective quality management system for the pharmaceutical industry, referred to as the Pharmaceutical Quality System. The guidance is intended to provide a comprehensive approach to an effective pharmaceutical quality system that is based on International Organization for Standardization (ISO) concepts, includes applicable good manufacturing practice (GMP) regulations and complements ICH guidances on "Q8 Pharmaceutical Development" and "Q9 Quality Risk Management."

On-line transmission electron microscopic image analysis of chromatin texture for differentiation of thyroid gland tumors.

Science.gov (United States)

Kriete, A; Schäffer, R; Harms, H; Aus, H M

1987-06-01

Nuclei of the cells from the thyroid gland were analyzed in a transmission electron microscope by direct TV scanning and on-line image processing. The method uses the advantages of a visual-perception model to detect structures in noisy and low-contrast images. The features analyzed include area, a form factor and texture parameters from the second derivative stage. Three tumor-free thyroid tissues, three follicular adenomas, three follicular carcinomas and three papillary carcinomas were studied. The computer-aided cytophotometric method showed that the most significant differences were the statistics of the chromatin texture features of homogeneity and regularity. These findings document the possibility of an automated differentiation of tumors at the ultrastructural level.

SU-C-207B-07: Deep Convolutional Neural Network Image Matching for Ultrasound Guidance in Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Zhu, N; Najafi, M; Hancock, S; Hristov, D [Stanford University Cancer Center, Palo Alto, CA (United States)

2016-06-15

Purpose: Robust matching of ultrasound images is a challenging problem as images of the same anatomy often present non-trivial differences. This poses an obstacle for ultrasound guidance in radiotherapy. Thus our objective is to overcome this obstacle by designing and evaluating an image blocks matching framework based on a two channel deep convolutional neural network. Methods: We extend to 3D an algorithmic structure previously introduced for 2D image feature learning [1]. To obtain the similarity between two 3D image blocks A and B, the 3D image blocks are divided into 2D patches Ai and Bi. The similarity is then calculated as the average similarity score of Ai and Bi. The neural network was then trained with public non-medical image pairs, and subsequently evaluated on ultrasound image blocks for the following scenarios: (S1) same image blocks with/without shifts (A and A-shift-x); (S2) non-related random block pairs; (S3) ground truth registration matched pairs of different ultrasound images with/without shifts (A-i and A-reg-i-shift-x). Results: For S1 the similarity scores of A and A-shift-x were 32.63, 18.38, 12.95, 9.23, 2.15 and 0.43 for x=ranging from 0 mm to 10 mm in 2 mm increments. For S2 the average similarity score for non-related block pairs was −1.15. For S3 the average similarity score of ground truth registration matched blocks A-i and A-reg-i-shift-0 (1≤i≤5) was 12.37. After translating A-reg-i-shift-0 by 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the average similarity scores of A-i and A-reg-i-shift-x were 11.04, 8.42, 4.56, 2.27, and 0.29 respectively. Conclusion: The proposed method correctly assigns highest similarity to corresponding 3D ultrasound image blocks despite differences in image content and thus can form the basis for ultrasound image registration and tracking.[1] Zagoruyko, Komodakis, “Learning to compare image patches via convolutional neural networks', IEEE CVPR 2015,pp.4353–4361.

SU-C-207B-07: Deep Convolutional Neural Network Image Matching for Ultrasound Guidance in Radiotherapy

International Nuclear Information System (INIS)

Zhu, N; Najafi, M; Hancock, S; Hristov, D

2016-01-01

Purpose: Robust matching of ultrasound images is a challenging problem as images of the same anatomy often present non-trivial differences. This poses an obstacle for ultrasound guidance in radiotherapy. Thus our objective is to overcome this obstacle by designing and evaluating an image blocks matching framework based on a two channel deep convolutional neural network. Methods: We extend to 3D an algorithmic structure previously introduced for 2D image feature learning [1]. To obtain the similarity between two 3D image blocks A and B, the 3D image blocks are divided into 2D patches Ai and Bi. The similarity is then calculated as the average similarity score of Ai and Bi. The neural network was then trained with public non-medical image pairs, and subsequently evaluated on ultrasound image blocks for the following scenarios: (S1) same image blocks with/without shifts (A and A-shift-x); (S2) non-related random block pairs; (S3) ground truth registration matched pairs of different ultrasound images with/without shifts (A-i and A-reg-i-shift-x). Results: For S1 the similarity scores of A and A-shift-x were 32.63, 18.38, 12.95, 9.23, 2.15 and 0.43 for x=ranging from 0 mm to 10 mm in 2 mm increments. For S2 the average similarity score for non-related block pairs was −1.15. For S3 the average similarity score of ground truth registration matched blocks A-i and A-reg-i-shift-0 (1≤i≤5) was 12.37. After translating A-reg-i-shift-0 by 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the average similarity scores of A-i and A-reg-i-shift-x were 11.04, 8.42, 4.56, 2.27, and 0.29 respectively. Conclusion: The proposed method correctly assigns highest similarity to corresponding 3D ultrasound image blocks despite differences in image content and thus can form the basis for ultrasound image registration and tracking.[1] Zagoruyko, Komodakis, “Learning to compare image patches via convolutional neural networks', IEEE CVPR 2015,pp.4353–4361.

78 FR 57395 - Guidance for Industry on Electronic Source Data in Clinical Investigations; Availability

Science.gov (United States)

2013-09-18

... providers and institutions, electronic laboratory reports, electronic medical images from devices, and... operating and maintenance costs, because sponsors and others already have and are experienced with using the computer-based equipment and software necessary to be consistent with the guidance. IV. Electronic Access...

Real-time tomosynthesis for radiation therapy guidance.

Science.gov (United States)

Hsieh, Scott S; Ng, Lydia W

2017-11-01

Fluoroscopy has been a tool of choice for monitoring treatments or interventions because of its extremely fast imaging times. However, the contrast obtained in fluoroscopy may be insufficient for certain clinical applications. In stereotactic ablative radiation therapy of the lung, fluoroscopy often lacks sufficient contrast for gating treatment. The purpose of this work is to describe and assess a real-time tomosynthesis design that can produce sufficient contrast for guidance of lung tumor treatment within a small field of view. Previous tomosynthesis designs in radiation oncology have temporal resolution on the order of seconds. The proposed system design uses parallel acquisition of multiple frames by simultaneously illuminating the field of view with multiple sources, enabling a temporal resolution of up to 30 frames per second. For a small field of view, a single flat-panel detector could be used if different sectors of the detector are assigned to specific sources. Simulated images were generated by forward projection of existing clinical datasets. The authors varied the number of tubes and the power of each tube in order to determine the impact on tumor visualization. Visualization of the tumor was much clearer in tomosynthesis than in fluoroscopy. Contrast generally improved with the number of sources used, and a minimum of four sources should be used. The high contrast of the lung allows very low system power, and in most cases, less than 1 mA was needed. More power is required in the lateral direction than the AP direction. The proposed system produces images adequate for real-time guidance of radiation therapy. The additional hardware requirements are modest, and the system is capable of imaging at high frame rates and low dose. Further development, including a prototype system and a dosimetry study, is needed to further evaluate the feasibility of this device for radiation therapy guidance. © 2017 American Association of Physicists in Medicine.

Computer aided solution for segmenting the neuron line in hippocampal microscope images

Science.gov (United States)

Albaidhani, Tahseen; Jassim, Sabah; Al-Assam, Hisham

2017-05-01

The brain Hippocampus component is known to be responsible for memory and spatial navigation. Its functionality depends on the status of different blood vessels within the Hippocampus and is severely impaired by Alzheimer's disease as a result blockage of increasing number of blood vessels by accumulation of amyloid-beta (Aβ) protein. Accurate counting of blood vessels within the Hippocampus of mice brain, from microscopic images, is an active research area for the understanding of Alzheimer's disease. Here, we report our work on automatic detection of the Region of Interest, i.e. the region in which blood vessels are located. This area typically falls between the hippocampus edge and the line of neurons within the Hippocampus. This paper proposes a new method to detect and exclude the neuron line to improve the accuracy of blood vessel counting because some neurons on it might lead to false positive cases as they look like blood vessels. Our proposed solution is based on using trainable segmentation approach with morphological operations, taking into account variation in colour, intensity values, and image texture. Experiments on a sufficient number of microscopy images of mouse brain demonstrate the effectiveness of the developed solution in preparation for blood vessels counting.

Develop guidance on how the end user should be involved in the development of OSS. Reflection on Task 4.3.3

International Nuclear Information System (INIS)

Lux, I.

1995-01-01

On the occasion of the 1993 CRP Meeting in Budapest the working group has determined the main lines of the elaboration of the task objective. The present Reflections are meant to give a somewhat deeper presentation of the thoughts put forward by the working group and also to propose a basis for further discussions before the final formulation of the guidance in question. 6 refs, 2 tabs

Side-Scan Sonar Image Mosaic Using Couple Feature Points with Constraint of Track Line Positions

Directory of Open Access Journals (Sweden)

Jianhu Zhao

2018-06-01

Full Text Available To obtain large-scale seabed surface image, this paper proposes a side-scan sonar (SSS image mosaic method using couple feature points (CFPs with constraint of track line positions. The SSS geocoded images are firstly used to form a coarsely mosaicked one and the overlapping areas between adjacent strip images can be determined based on geographic information. Inside the overlapping areas, the feature point (FP detection and registration operation are adopted for both strips. According to the detected CFPs and track line positions, an adjustment model is established to accommodate complex local distortions as well as ensure the global stability. This proposed method effectively solves the problem of target ghosting or dislocation and no accumulated errors arise in the mosaicking process. Experimental results show that the finally mosaicked image correctly reflects the object distribution, which is meaningful for understanding and interpreting seabed topography.

WE-H-207B-03: MRI Guidance in the Radiation Therapy Clinic: Site-Specific Discussions

International Nuclear Information System (INIS)

Shang, C.

2016-01-01

In recent years, steady progress has been made towards the implementation of MRI in external beam radiation therapy for processes ranging from treatment simulation to in-room guidance. Novel procedures relying mostly on MR data are currently implemented in the clinic. This session will cover topics such as (a) commissioning and quality control of the MR in-room imagers and simulators specific to RT, (b) treatment planning requirements, constraints and challenges when dealing with various MR data, (c) quantification of organ motion with an emphasis on treatment delivery guidance, and (d) MR-driven strategies for adaptive RT workflows. The content of the session was chosen to address both educational and practical key aspects of MR guidance. Learning Objectives: Good understanding of MR testing recommended for in-room MR imaging as well as image data validation for RT chain (e.g. image transfer, filtering for consistency, spatial accuracy, manipulation for task specific); Familiarity with MR-based planning procedures: motivation, core workflow requirements, current status, challenges; Overview of the current methods for the quantification of organ motion; Discussion on approaches for adaptive treatment planning and delivery. T. Stanescu - License agreement with Modus Medical Devices to develop a phantom for the quantification of MR image system-related distortions.; T. Stanescu, N/A

WE-H-207B-03: MRI Guidance in the Radiation Therapy Clinic: Site-Specific Discussions

Energy Technology Data Exchange (ETDEWEB)

Shang, C. [Boca Raton Regional Hospital (United States)

2016-06-15

In recent years, steady progress has been made towards the implementation of MRI in external beam radiation therapy for processes ranging from treatment simulation to in-room guidance. Novel procedures relying mostly on MR data are currently implemented in the clinic. This session will cover topics such as (a) commissioning and quality control of the MR in-room imagers and simulators specific to RT, (b) treatment planning requirements, constraints and challenges when dealing with various MR data, (c) quantification of organ motion with an emphasis on treatment delivery guidance, and (d) MR-driven strategies for adaptive RT workflows. The content of the session was chosen to address both educational and practical key aspects of MR guidance. Learning Objectives: Good understanding of MR testing recommended for in-room MR imaging as well as image data validation for RT chain (e.g. image transfer, filtering for consistency, spatial accuracy, manipulation for task specific); Familiarity with MR-based planning procedures: motivation, core workflow requirements, current status, challenges; Overview of the current methods for the quantification of organ motion; Discussion on approaches for adaptive treatment planning and delivery. T. Stanescu - License agreement with Modus Medical Devices to develop a phantom for the quantification of MR image system-related distortions.; T. Stanescu, N/A.

Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance.

Directory of Open Access Journals (Sweden)

Christopher A Mela

Full Text Available We have developed novel stereoscopic wearable multimodal intraoperative imaging and display systems entitled Integrated Imaging Goggles for guiding surgeries. The prototype systems offer real time stereoscopic fluorescence imaging and color reflectance imaging capacity, along with in vivo handheld microscopy and ultrasound imaging. With the Integrated Imaging Goggle, both wide-field fluorescence imaging and in vivo microscopy are provided. The real time ultrasound images can also be presented in the goggle display. Furthermore, real time goggle-to-goggle stereoscopic video sharing is demonstrated, which can greatly facilitate telemedicine. In this paper, the prototype systems are described, characterized and tested in surgeries in biological tissues ex vivo. We have found that the system can detect fluorescent targets with as low as 60 nM indocyanine green and can resolve structures down to 0.25 mm with large FOV stereoscopic imaging. The system has successfully guided simulated cancer surgeries in chicken. The Integrated Imaging Goggle is novel in 4 aspects: it is (a the first wearable stereoscopic wide-field intraoperative fluorescence imaging and display system, (b the first wearable system offering both large FOV and microscopic imaging simultaneously,

Vessel Segmentation in Retinal Images Using Multi-scale Line Operator and K-Means Clustering.

Science.gov (United States)

Saffarzadeh, Vahid Mohammadi; Osareh, Alireza; Shadgar, Bita

2014-04-01

Detecting blood vessels is a vital task in retinal image analysis. The task is more challenging with the presence of bright and dark lesions in retinal images. Here, a method is proposed to detect vessels in both normal and abnormal retinal fundus images based on their linear features. First, the negative impact of bright lesions is reduced by using K-means segmentation in a perceptive space. Then, a multi-scale line operator is utilized to detect vessels while ignoring some of the dark lesions, which have intensity structures different from the line-shaped vessels in the retina. The proposed algorithm is tested on two publicly available STARE and DRIVE databases. The performance of the method is measured by calculating the area under the receiver operating characteristic curve and the segmentation accuracy. The proposed method achieves 0.9483 and 0.9387 localization accuracy against STARE and DRIVE respectively.

Aliasing effects in digital images of line-pair phantoms

International Nuclear Information System (INIS)

Albert, Michael; Beideck, Daniel J.; Bakic, Predrag R.; Maidment, Andrew D.A.

2002-01-01

Line-pair phantoms are commonly used for evaluating screen-film systems. When imaged digitally, aliasing effects give rise to additional periodic patterns. This paper examines one such effect that medical physicists are likely to encounter, and which can be used as an indicator of super-resolution

Time-Varying Biased Proportional Guidance with Seeker’s Field-of-View Limit

OpenAIRE

Yang, Zhe; Wang, Hui; Lin, Defu

2016-01-01

Traditional guidance laws with range-to-go information or time-to-go estimation may not be implemented in passive homing missiles since passive seekers cannot measure relative range directly. A time-varying biased proportional guidance law, which only uses line-of-sight (LOS) rate and look angle information, is proposed to satisfy both impact angle constraint and seeker’s field-of-view (FOV) limit. In the proposed guidance law, two time-varying bias terms are applied to divide the trajectory ...

Line-scanning confocal microscopy for high-resolution imaging of upconverting rare-earth-based contrast agents

Science.gov (United States)

Higgins, Laura M.; Zevon, Margot; Ganapathy, Vidya; Sheng, Yang; Tan, Mei Chee; Riman, Richard E.; Roth, Charles M.; Moghe, Prabhas V.; Pierce, Mark C.

2015-01-01

Abstract. Rare-earth (RE) doped nanocomposites emit visible luminescence when illuminated with continuous wave near-infrared light, making them appealing candidates for use as contrast agents in biomedical imaging. However, the emission lifetime of these materials is much longer than the pixel dwell times used in scanning intravital microscopy. To overcome this limitation, we have developed a line-scanning confocal microscope for high-resolution, optically sectioned imaging of samples labeled with RE-based nanomaterials. Instrument performance is quantified using calibrated test objects. NaYF4:Er,Yb nanocomposites are imaged in vitro, and in ex vivo tissue specimens, with direct comparison to point-scanning confocal microscopy. We demonstrate that the extended pixel dwell time of line-scanning confocal microscopy enables subcellular-level imaging of these nanomaterials while maintaining optical sectioning. The line-scanning approach thus enables microscopic imaging of this emerging class of contrast agents for preclinical studies, with the potential to be adapted for real-time in vivo imaging in the clinic. PMID:26603495

Exoatmospheric intercepts using zero effort miss steering for midcourse guidance

Science.gov (United States)

Newman, Brett

The suitability of proportional navigation, or an equivalent zero effort miss formulation, for exatmospheric intercepts during midcourse guidance, followed by a ballistic coast to the endgame, is addressed. The problem is formulated in terms of relative motion in a general, three dimensional framework. The proposed guidance law for the commanded thrust vector orientation consists of the sum of two terms: (1) along the line of sight unit direction and (2) along the zero effort miss component perpendicular to the line of sight and proportional to the miss itself and a guidance gain. If the guidance law is to be suitable for longer range targeting applications with significant ballistic coasting after burnout, determination of the zero effort miss must account for the different gravitational accelerations experienced by each vehicle. The proposed miss determination techniques employ approximations for the true differential gravity effect and thus, are less accurate than a direct numerical propagation of the governing equations, but more accurate than a baseline determination, which assumes equal accelerations for both vehicles. Approximations considered are constant, linear, quadratic, and linearized inverse square models. Theoretical results are applied to a numerical engagement scenario and the resulting performance is evaluated in terms of the miss distances determined from nonlinear simulation.

Extended ellipse-line-ellipse trajectory for long-object cone-beam imaging with a mounted C-arm system

International Nuclear Information System (INIS)

Yu, Zhicong; Noo, Frédéric; Lauritsch, Günter; Dennerlein, Frank; Mao, Yanfei; Hornegger, Joachim

2016-01-01

Recent reports show that three-dimensional cone-beam (CB) imaging with a floor-mounted (or ceiling-mounted) C-arm system has become a valuable tool in interventional radiology. Currently, a circular short scan is used for data acquisition, which inevitably yields CB artifacts and a short coverage in the direction of the patient table. To overcome these two limitations, a more sophisticated data acquisition geometry is needed. This geometry should be complete in terms of Tuy’s condition and should allow continuous scanning, while being compatible with the mechanical constraints of mounted C-arm systems. Additionally, the geometry should allow accurate image reconstruction from truncated data. One way to ensure such a feature is to adopt a trajectory that provides full R-line coverage within the field-of-view (FOV). An R-line is any segment of line that connects two points on a source trajectory, and the R-line coverage is the set of points that belong to an R-line. In this work, we propose a novel geometry called the extended ellipse-line-ellipse (ELE) for long-object imaging with a mounted C-arm system. This trajectory is built from modules consisting of two elliptical arcs connected by a line. We demonstrate that the extended ELE can be configured in many ways so that full R-line coverage is guaranteed. Both tight and relaxed parametric settings are presented. All results are supported by extensive mathematical proofs provided in appendices. Our findings make the extended ELE trajectory attractive for axially-extended FOV imaging in interventional radiology. (paper)

Radon: guidance on protective measures for new dwellings

International Nuclear Information System (INIS)

1991-01-01

This report gives guidance for reducing the presence of radon in new dwellings and hence reducing the risk to occupants of exposure to radon. This is a follow-up to the interim guidance of 1988. The report provides comprehensive practical details on the methods of protection including both primary and secondary measures. (UK)

Machine Visual Guidance For An Autonomous Undersea Submersible

Science.gov (United States)

Nguyen, Hoa G.; Kaomea, Peter K.; Heckman, Paul J.

1988-12-01

Optical imaging is the preferred sensory modality for underwater robotic activities requiring high resolution at close range, such as station keeping, docking, control of manipulator, and object retrieval. Machine vision will play a vital part in the design of next generation autonomous underwater submersibles. This paper describes an effort to demonstrate that real-time vision-based guidance and control of autonomous underwater submersibles is possible with compact, low-power, and vehicle-imbeddable hardware. The Naval Ocean Systems Center's EAVE-WEST (Experimental Autonomous Vehicle-West) submersible is being used as the testbed. The vision hardware consists of a PC-bus video frame grabber and an IBM-PC/AT compatible single-board computer, both residing in the artificial intelligence/vision electronics bottle of the submersible. The specific application chosen involves the tracking of underwater buoy cables. Image recognition is performed in two steps. Feature points are identified in the underwater video images using a technique which detects one-dimensional local brightness minima and maxima. Hough transformation is then used to detect the straight line among these feature points. A hierarchical coarse-to-fine processing method is employed which terminates when enough feature points have been identified to allow a reliable fit. The location of the cable identified is then reported to the vehicle controller computer for automatic steering control. The process currently operates successfully with a throughput of approximately 2 frames per second.

Guidance and navigation for rendezvous with an uncooperative target

Science.gov (United States)

Telaar, J.; Schlaile, C.; Sommer, J.

2018-06-01

This paper presents a guidance strategy for a rendezvous with an uncooperative target. In the applied design reference mission, a spiral approach is commanded ensuring a collision-free relative orbit due to e/i-vector separation. The dimensions of the relative orbit are successively reduced by Δv commands which at the same time improve the observability of the relative state. The navigation is based on line-of-sight measurements. The relative state is estimated by an extended Kalman filter (EKF). The performance of this guidance and navigation strategy is demonstrated by extensive Monte Carlo simulations taking into account all major uncertainties like measurement errors, Δv execution errors, and differential drag.

Line-Constrained Camera Location Estimation in Multi-Image Stereomatching.

Science.gov (United States)

Donné, Simon; Goossens, Bart; Philips, Wilfried

2017-08-23

Stereomatching is an effective way of acquiring dense depth information from a scene when active measurements are not possible. So-called lightfield methods take a snapshot from many camera locations along a defined trajectory (usually uniformly linear or on a regular grid-we will assume a linear trajectory) and use this information to compute accurate depth estimates. However, they require the locations for each of the snapshots to be known: the disparity of an object between images is related to both the distance of the camera to the object and the distance between the camera positions for both images. Existing solutions use sparse feature matching for camera location estimation. In this paper, we propose a novel method that uses dense correspondences to do the same, leveraging an existing depth estimation framework to also yield the camera locations along the line. We illustrate the effectiveness of the proposed technique for camera location estimation both visually for the rectification of epipolar plane images and quantitatively with its effect on the resulting depth estimation. Our proposed approach yields a valid alternative for sparse techniques, while still being executed in a reasonable time on a graphics card due to its highly parallelizable nature.

Career guidance in communities

DEFF Research Database (Denmark)

Thomsen, Rie

for the development of a critically reflexive career guidance practice. The considerations are organised around seven elements. 1. Creating opportunity, structure and access 2. Entering a community and increasing visibility 3. Providing guidance in communities 4. Exploring potentials in guidance situations 5...... in career guidance practices as well as in the lives of the people in the communities. This paper falls into two parts: The first part considers the collective as the starting point for the development of meaningful career guidance activities. Based on previous research on career guidance in communities......The aim of this paper is to inspire practitioners and professionals to leave their offices to bring career guidance into communities that might not identify with career guidance in the first instance. By making the effort to engage with communities, practitioners may bring about a critical change...

Novel Infiltration Diagnostics based on Laser-line Scanning and Infrared Temperature Field Imaging

Energy Technology Data Exchange (ETDEWEB)

Wang, Xinwei [Iowa State Univ., Ames, IA (United States)

2017-12-08

This project targets the building energy efficiency problems induced by building infiltration/leaks. The current infiltration inspection techniques often require extensive visual inspection and/or whole building pressure test. These current techniques cannot meet more than three of the below five criteria of ideal infiltration diagnostics: 1. location and extent diagnostics, 2. building-level application, 3. least surface preparation, 4. weather-proof, and 5. non-disruption to building occupants. These techniques are either too expensive or time consuming, and often lack accuracy and repeatability. They are hardly applicable to facades/facades section. The goal of the project was to develop a novel infiltration diagnostics technology based on laser line-scanning and simultaneous infrared temperature imaging. A laboratory scale experimental setup was designed to mimic a model house of well-defined pressure difference below or above the outside pressure. Algorithms and Matlab-based programs had been developed for recognition of the hole location in infrared images. Our experiment based on laser wavelengths of 450 and 1550 nm and laser beam diameters of 4-25 mm showed that the location of the holes could be identified using laser heating; the diagnostic approach however could not readily distinguish between infiltration and non-infiltration points. To significantly improve the scanning throughput and recognition accuracy, a second approach was explored, developed, and extensively tested. It incorporates a liquid spray on the surface to induce extra phase change cooling effect. In this spray method, we termed it as PECIT (Phase-change Enhanced Cooling Infrared Thermography), phase-change enhanced cooling was used, which significantly amplifies the effect of air flow (infiltration and exfiltration). This heat transfer method worked extremely well to identify infiltration and exfiltration locations with high accuracy and increased throughput. The PECIT technique was

The establishment of enteral nutrition with minimally-invasive interventional procedure under endoscopic or imaging guidance

International Nuclear Information System (INIS)

Li Feng; Cheng Yingsheng

2010-01-01

For patients unable to get the necessary nutrition orally, a variety of techniques,including surgical way, to make gastrostomy with tube placement have been employed. For recent years, gastrostomy and tube placement with the help of endoscopic guidance or percutaneous interventional management has been developed, which is superior to surgical procedure in minimizing injuries, decreasing cost and reducing complications. In certain clinical situations, both endoscopic method and interventional method can be employed. This paper aims to make a comprehensive review of the indications, techniques and skills, advantages and disadvantages of both the endoscopy-guided and the imaging-guided percutaneous gastrojejunostomy for the establishment of enteral nutrition. (authors)

Development of a real time imaging-based guidance system of magnetic nanoparticles for targeted drug delivery

International Nuclear Information System (INIS)

Zhang, Xingming; Le, Tuan-Anh; Yoon, Jungwon

2017-01-01

Targeted drug delivery using magnetic nanoparticles is an efficient technique as molecules can be directed toward specific tissues inside a human body. For the first time, we implemented a real-time imaging-based guidance system of nanoparticles using untethered electro-magnetic devices for simultaneous guiding and tracking. In this paper a low-amplitude-excitation-field magnetic particle imaging (MPI) is introduced. Based on this imaging technology, a hybrid system comprised of an electromagnetic actuator and MPI was used to navigate nanoparticles in a non-invasive way. The real-time low-amplitude-excitation-field MPI and electromagnetic actuator of this navigation system are achieved by applying a time-division multiplexing scheme to the coil topology. A one dimensional nanoparticle navigation system was built to demonstrate the feasibility of the proposed approach and it could achieve a 2 Hz navigation update rate with the field gradient of 3.5 T/m during the imaging mode and 8.75 T/m during the actuation mode. Particles with both 90 nm and 5 nm diameters could be successfully manipulated and monitored in a tube through the proposed system, which can significantly enhance targeting efficiency and allow precise analysis in a real drug delivery. - Highlights: • A real-time system comprised of an electromagnetic actuator and a low-amplitude-excitation-field MPI can navigate magnetic nanoparticles. • The imaging scheme is feasible to enlarge field of view size. • The proposed navigation system can be cost efficient, compact, and optimized for targeting of the nanoparticles.

Development of a real time imaging-based guidance system of magnetic nanoparticles for targeted drug delivery

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xingming [School of Naval Architecture and Ocean Engineering, Harbin Institute of Technology at Weihai, Weihai, Shandong (China); School of Mechanical and Aerospace Engineering & ReCAPT, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Le, Tuan-Anh [School of Mechanical and Aerospace Engineering & ReCAPT, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Yoon, Jungwon, E-mail: jwyoon@gnu.ac.kr [School of Mechanical and Aerospace Engineering & ReCAPT, Gyeongsang National University, Jinju 660-701 (Korea, Republic of)

2017-04-01

Targeted drug delivery using magnetic nanoparticles is an efficient technique as molecules can be directed toward specific tissues inside a human body. For the first time, we implemented a real-time imaging-based guidance system of nanoparticles using untethered electro-magnetic devices for simultaneous guiding and tracking. In this paper a low-amplitude-excitation-field magnetic particle imaging (MPI) is introduced. Based on this imaging technology, a hybrid system comprised of an electromagnetic actuator and MPI was used to navigate nanoparticles in a non-invasive way. The real-time low-amplitude-excitation-field MPI and electromagnetic actuator of this navigation system are achieved by applying a time-division multiplexing scheme to the coil topology. A one dimensional nanoparticle navigation system was built to demonstrate the feasibility of the proposed approach and it could achieve a 2 Hz navigation update rate with the field gradient of 3.5 T/m during the imaging mode and 8.75 T/m during the actuation mode. Particles with both 90 nm and 5 nm diameters could be successfully manipulated and monitored in a tube through the proposed system, which can significantly enhance targeting efficiency and allow precise analysis in a real drug delivery. - Highlights: • A real-time system comprised of an electromagnetic actuator and a low-amplitude-excitation-field MPI can navigate magnetic nanoparticles. • The imaging scheme is feasible to enlarge field of view size. • The proposed navigation system can be cost efficient, compact, and optimized for targeting of the nanoparticles.

Expression image data of Drosophila GAL4 enhancer trap lines - GETDB | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available List Contact us GETDB Expression image data of Drosophila GAL4 enhancer trap lines Data detail Data name Exp...ta contents 3,075 expression image data by developmental stages of Drosophila Images are classified into the...escription Download License Update History of This Database Site Policy | Contact Us Expression image data of Drosophila GAL4 enhancer trap lines - GETDB | LSDB Archive ... ...ression image data of Drosophila GAL4 enhancer trap lines DOI 10.18908/lsdba.nbdc00236-004 Description of da

Automatic Vessel Segmentation on Retinal Images

Institute of Scientific and Technical Information of China (English)

Chun-Yuan Yu; Chia-Jen Chang; Yen-Ju Yao; Shyr-Shen Yu

2014-01-01

Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hyper-tension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm. In this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE (digital retinal images for vessel extraction) retinal database, which is much better than other methods.

High-speed adaptive optics line scan confocal retinal imaging for human eye.

Science.gov (United States)

Lu, Jing; Gu, Boyu; Wang, Xiaolin; Zhang, Yuhua

2017-01-01

Continuous and rapid eye movement causes significant intraframe distortion in adaptive optics high resolution retinal imaging. To minimize this artifact, we developed a high speed adaptive optics line scan confocal retinal imaging system. A high speed line camera was employed to acquire retinal image and custom adaptive optics was developed to compensate the wave aberration of the human eye's optics. The spatial resolution and signal to noise ratio were assessed in model eye and in living human eye. The improvement of imaging fidelity was estimated by reduction of intra-frame distortion of retinal images acquired in the living human eyes with frame rates at 30 frames/second (FPS), 100 FPS, and 200 FPS. The device produced retinal image with cellular level resolution at 200 FPS with a digitization of 512×512 pixels/frame in the living human eye. Cone photoreceptors in the central fovea and rod photoreceptors near the fovea were resolved in three human subjects in normal chorioretinal health. Compared with retinal images acquired at 30 FPS, the intra-frame distortion in images taken at 200 FPS was reduced by 50.9% to 79.7%. We demonstrated the feasibility of acquiring high resolution retinal images in the living human eye at a speed that minimizes retinal motion artifact. This device may facilitate research involving subjects with nystagmus or unsteady fixation due to central vision loss.

The Imaging and Medical Beam Line at the Australian Synchrotron

Science.gov (United States)

Hausermann, Daniel; Hall, Chris; Maksimenko, Anton; Campbell, Colin

2010-07-01

As a result of the enthusiastic support from the Australian biomedical, medical and clinical communities, the Australian Synchrotron is constructing a world-class facility for medical research, the `Imaging and Medical Beamline'. The IMBL began phased commissioning in late 2008 and is scheduled to commence the first clinical research programs with patients in 2011. It will provide unrivalled x-ray facilities for imaging and radiotherapy for a wide range of research applications in diseases, treatments and understanding of physiological processes. The main clinical research drivers are currently high resolution and sensitivity cardiac and breast imaging, cell tracking applied to regenerative and stem cell medicine and cancer therapies. The beam line has a maximum source to sample distance of 136 m and will deliver a 60 cm by 4 cm x-ray beam1—monochromatic and white—to a three storey satellite building fully equipped for pre-clinical and clinical research. Currently operating with a 1.4 Tesla multi-pole wiggler, it will upgrade to a 4.2 Tesla device which requires the ability to handle up to 21 kW of x-ray power at any point along the beam line. The applications envisaged for this facility include imaging thick objects encompassing materials, humans and animals. Imaging can be performed in the range 15-150 keV. Radiotherapy research typically requires energies between 30 and 120 keV, for both monochromatic and broad beam.

Expanded beam spectro-ellipsometry for big area on-line monitoring

Science.gov (United States)

Fried, M.; Major, C.; Juhasz, G.; Petrik, P.; Horvath, Z.

2015-05-01

Non-destructive analysing tools are needed at all stages of thin film process-development, especially photovoltaic (PV) development, and on production lines. In the case of thin films, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity are important parameters. An important focus is to express the dielectric functions of each component material in terms of a handful of wavelength independent parameters whose variation can cover all process variants of that material. With the resulting database, spectroscopic ellipsometry coupled with multilayer analysis can be developed for on-line point-by-point mapping and on-line line-by-line imaging. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels or big area (even 450 mm diameter) Si-wafers in developing labs but it is slow in the on-line mode when only 15 points can be obtained (within 1 min) as a 120 cm long panel moves by the mapping station. Last years [M. Fried et al, Thin Solid Films 519, 2730 (2011)], a new instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl=350- 1000 nm) data. Earlier a single 30 point line image could be collected in 10 s over a 15 cm width of PV material. Recent years we have built a 30, a 45 and a 60 cm width expanded beam ellipsometer which speed is increased by 10x. Now, 1800 points can be mapped in a 1 min traverse of a 60*120 cm PV panel or flexible roll-to-roll substrate.

Line-Enhanced Deformable Registration of Pulmonary Computed Tomography Images Before and After Radiation Therapy With Radiation-Induced Fibrosis

Science.gov (United States)

Sensakovic, William F.; Maxim, Peter; Diehn, Maximilian; Loo, Billy W.; Xing, Lei

2018-01-01

Purpose: The deformable registration of pulmonary computed tomography images before and after radiation therapy is challenging due to anatomic changes from radiation fibrosis. We hypothesize that a line-enhanced registration algorithm can reduce landmark error over the entire lung, including the irradiated regions, when compared to an intensity-based deformable registration algorithm. Materials: Two intensity-based B-spline deformable registration algorithms of pre-radiation therapy and post-radiation therapy images were compared. The first was a control intensity–based algorithm that utilized computed tomography images without modification. The second was a line enhancement algorithm that incorporated a Hessian-based line enhancement filter prior to deformable image registration. Registrations were evaluated based on the landmark error between user-identified landmark pairs and the overlap ratio. Results: Twenty-one patients with pre-radiation therapy and post-radiation therapy scans were included. The median time interval between scans was 1.2 years (range: 0.3-3.3 years). Median landmark errors for the line enhancement algorithm were significantly lower than those for the control algorithm over the entire lung (1.67 vs 1.83 mm; P 5 Gy (2.25 vs 3.31; P 5 Gy dose interval demonstrated a significant inverse relationship with post-radiation therapy fibrosis enhancement after line enhancement filtration (Pearson correlation coefficient = −0.48; P = .03). Conclusion: The line enhancement registration algorithm is a promising method for registering images before and after radiation therapy. PMID:29343206

A non-iterative twin image elimination method with two in-line digital holograms

Science.gov (United States)

Kim, Jongwu; Lee, Heejung; Jeon, Philjun; Kim, Dug Young

2018-02-01

We propose a simple non-iterative in-line holographic measurement method which can effectively eliminate a twin image in digital holographic 3D imaging. It is shown that a twin image can be effectively eliminated with only two measured holograms by using a simple numerical propagation algorithm and arithmetic calculations.

Transsphenoidal pituitary resection with intraoperative MR guidance: preliminary results

Science.gov (United States)

Pergolizzi, Richard S., Jr.; Schwartz, Richard B.; Hsu, Liangge; Wong, Terence Z.; Black, Peter M.; Martin, Claudia; Jolesz, Ferenc A.

1999-05-01

The use of intraoperative MR image guidance has the potential to improve the precision, extent and safety of transsphenoidal pituitary resections. At Brigham and Women's Hospital, an open-bore configuration 0.5T MR system (SIGNA SP, GE Medical Systems, Milwaukee, WI) has been used to provide image guidance for nine transsphenoidal pituitary adenoma resections. The intraoperative MR system allowed the radiologist to direct the surgeon toward the sella turcica successfully while avoiding the cavernous sinus, optic chiasm and other sensitive structures. Imaging performed during the surgery monitored the extent of resection and allowed for removal of tumor beyond the surgeon's view in five cases. Dynamic MR imaging was used to distinguish residual tumor from normal gland and postoperative changes permitting more precise tumor localization. A heme-sensitive long TE gradient echo sequence was used to evaluate for the presence of hemorrhagic debris. All patients tolerated the procedure well without significant complications.

WE-E-BRF-01: The ESTRO-AAPM Joint Symposium On Imaging for Proton Treatment Planning and Guidance

Energy Technology Data Exchange (ETDEWEB)

Parodi, K [Ludwig-Maximilians-University Munich, Garching, Bavaria (Germany); Dauvergne, D [Institut de Physique Nucleaire de Lyon, Lyon (France); Kruse, J [Mayo Clinic, Rochester, MN (United States)

2014-06-15

beam scale for active proton beam delivery in homogenous targets. The development of gamma cameras, that has been studied by several groups worldwide over the last years, now reaches - for some of them - the stage of being applicable in clinical conditions, with real size prototypes and count rate capability matching the therapeutic beam intensities. We will review the different concepts of gamma cameras, the advantages and limitations of this method, and the main challenges that should still be overcome before the widespread of prompt gamma quality assurance for proton and hadrontherapy. Jon Kruse (Mayo Clinic, Rochester, MN, USA) Treatment simulation images for proton therapy are used to determine proton stopping power and range in the patient. This talk will discuss the careful control of CT numbers and conversion of CT number to stopping power required in proton therapy. Imaging for treatment guidance of proton therapy also presents unique challenges which will be addressed. Among them are the enhanced relationship between internal anatomy changes and dosimetry, the need for imaging to support adaptive planning protocols, and high operational efficiency. Learning Objectives: To learn about the possibilities of using activation products to determine the range of particle beams in a patient treatment setting To be informed on an alternative methodology using prompt gamma detectors To understand the impact of the accuracy of the knowledge of the patient information with respect to the delivered treatment.

Improved cancer diagnostics by different image processing techniques on OCT images

Science.gov (United States)

Kanawade, Rajesh; Lengenfelder, Benjamin; Marini Menezes, Tassiana; Hohmann, Martin; Kopfinger, Stefan; Hohmann, Tim; Grabiec, Urszula; Klämpfl, Florian; Gonzales Menezes, Jean; Waldner, Maximilian; Schmidt, Michael

2015-07-01

Optical-coherence tomography (OCT) is a promising non-invasive, high-resolution imaging modality which can be used for cancer diagnosis and its therapeutic assessment. However, speckle noise makes detection of cancer boundaries and image segmentation problematic and unreliable. Therefore, to improve the image analysis for a precise cancer border detection, the performance of different image processing algorithms such as mean, median, hybrid median filter and rotational kernel transformation (RKT) for this task is investigated. This is done on OCT images acquired from an ex-vivo human cancerous mucosa and in vitro by using cultivated tumour applied on organotypical hippocampal slice cultures. The preliminary results confirm that the border between the healthy and the cancer lesions can be identified precisely. The obtained results are verified with fluorescence microscopy. This research can improve cancer diagnosis and the detection of borders between healthy and cancerous tissue. Thus, it could also reduce the number of biopsies required during screening endoscopy by providing better guidance to the physician.

Sacro-iliac joint arthrography in low back pain: feasibility of MRI guidance

International Nuclear Information System (INIS)

Ojala, Risto; Klemola, Rauli; Karppinen, Jaro; Sequeiros, Roberto Blanco; Tervonen, Osmo

2001-01-01

Objective: Evaluation of the feasibility of MR-guidance in sacro-iliac joint arthrography in patients whose low back pain is suspected to arise from the sacro-iliac joint (SIJ). Methods and patients: Twenty patients with low back pain underwent MR-guided sacro-iliac joint arthrography. Needles made from titanium (size 20 G, MDTech, USA) were used. For image guidance a 0.23T open-configuration C arm magnet (Proview, Marconi Medical Systems, USA) with special interventional hardware and software package (I-Path 200, Marconi Medical Systems) containing an MR compatible in-room console, large-screen (36'') display, optical navigator and accompanying software with dedicated sequences was used. No other image guidance modalities were used. Results: MR-guided SIJ arthrography was successfully performed in all twenty patients without complications. The optimal imaging sequence both for preoperative and intraoperative images was 3D-Gradient Echo sequence. The dispersal of the injected saline and anaesthetic could be determined inside the joint in all cases with heavily T2-weighted fast spin echo sequence. In the present study, 60% of the patients had significant reduction of pain after sacro-iliac joint arthrography and sacro-iliac joint was considered to be the source of patients low back pain in these patients. Conclusion: The present study shows that MR guidance with open configuration low field scanner is an accurate guiding method for sacro-iliac joint arthrography

Effects of line fiducial parameters and beamforming on ultrasound calibration

OpenAIRE

Ameri, Golafsoun; Baxter, John S. H.; McLeod, A. Jonathan; Peters, Terry M.; Chen, Elvis C. S.

2017-01-01

Ultrasound (US)-guided interventions are often enhanced via integration with an augmented reality environment, a necessary component of which is US calibration. Calibration requires the segmentation of fiducials, i.e., a phantom, in US images. Fiducial localization error (FLE) can decrease US calibration accuracy, which fundamentally affects the total accuracy of the interventional guidance system. Here, we investigate the effects of US image reconstruction techniques as well as phantom mater...

MO-DE-210-06: Development of a Supercompounded 3D Volumetric Ultrasound Image Guidance System for Prone Accelerated Partial Breast Irradiation (APBI)

Energy Technology Data Exchange (ETDEWEB)

Chiu, T; Hrycushko, B; Zhao, B; Jiang, S; Gu, X [UT Southwestern Medical Center, Dallas, TX (United States)

2015-06-15

Purpose: For early-stage breast cancer, accelerated partial breast irradiation (APBI) is a cost-effective breast-conserving treatment. Irradiation in a prone position can mitigate respiratory induced breast movement and achieve maximal sparing of heart and lung tissues. However, accurate dose delivery is challenging due to breast deformation and lumpectomy cavity shrinkage. We propose a 3D volumetric ultrasound (US) image guidance system for accurate prone APBI Methods: The designed system, set beneath the prone breast board, consists of a water container, an US scanner, and a two-layer breast immobilization cup. The outer layer of the breast cup forms the inner wall of water container while the inner layer is attached to patient breast directly to immobilization. The US transducer scans is attached to the outer-layer of breast cup at the dent of water container. Rotational US scans in a transverse plane are achieved by simultaneously rotating water container and transducer, and multiple transverse scanning forms a 3D scan. A supercompounding-technique-based volumetric US reconstruction algorithm is developed for 3D image reconstruction. The performance of the designed system is evaluated with two custom-made gelatin phantoms containing several cylindrical inserts filled in with water (11% reflection coefficient between materials). One phantom is designed for positioning evaluation while the other is for scaling assessment. Results: In the positioning evaluation phantom, the central distances between the inserts are 15, 20, 30 and 40 mm. The distances on reconstructed images differ by −0.19, −0.65, −0.11 and −1.67 mm, respectively. In the scaling evaluation phantom, inserts are 12.7, 19.05, 25.40 and 31.75 mm in diameter. Measured inserts’ sizes on images differed by 0.23, 0.19, −0.1 and 0.22 mm, respectively. Conclusion: The phantom evaluation results show that the developed 3D volumetric US system can accurately localize target position and determine

On-line analysis of water contamination by organic compounds; On-line-Analytik der Wasserverschmutzung durch organische Substanzen

Energy Technology Data Exchange (ETDEWEB)

Wagt, R. van der; Vos, F. de [Skalar Analytical (Netherlands); Babichenko, S.; Poryvkina, L. [Institute of Ecology, Tallinn (Estonia)

1999-08-01

In many environmental applications decomposing the mixture of substances in the water into its various chemical ingredients, for subsequent analysis, is a very complicated task. The most productive approach to on-line diagnosis is to treat the object as an integral spectroscopic sample, characterized by certain specific Spectral Fluorescent Signatures (SFS). The SFS are recorded as a matrix of fluorescent intensity of organic compounds in water, in co-ordinates of excitation and emission spectra, providing a three-dimensional spectrum. Spectral windows of SFS are defined by fluorescent characteristics of basic groups of organic substances in the water sample. The novel Skalar Fluo Imager, based on this principle, is intended for the analysis of organic compounds in natural, domestic, and technological waters in an on-line mode. (orig.) [German] In vielen Umweltschutzanwendungen stellt die Auftrennung eines Substanzgemisches zum Zweck der Analyse eine sehr komplizierte Aufgabe dar. Ein erfolgversprechender Ansatz fuer eine on-line-Diagnostik besteht darin, das Objekt als integrale Spektroskopieprobe zu betrachten, die durch bestimmte spezifische Spektral-Fluoreszenz-Signaturen (SFS) charakterisiert wird. Diese werden als Fluoreszenz-Intensitaets-Matrix organischer Verbindungen in Wasser dargestellt, mit Anregungs- und Emissionsspektren als weiteren Koordinaten, wodurch ein dreidimensionales Spektrum entsteht. Spektrale Fenster der SFS sind definiert als Fluoreszenzcharakteristika von Funktionsgruppen organischer Substanzen in der Wasserprobe. Der auf diesem Prinzip basierende Skalar Fluo Imager ist fuer die on-line-Analyse organischer Bestandteile in natuerlichen, Haus- und technischen Waessern gedacht. (orig.)

Fusion guidance in endovascular peripheral artery interventions: a feasibility study.

Science.gov (United States)

Sailer, Anna M; de Haan, Michiel W; de Graaf, Rick; van Zwam, Willem H; Schurink, Geert Willem H; Nelemans, Patricia J; Wildberger, Joachim E; Das, Marco

2015-04-01

This study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Fusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography. Average time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation). Fluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.

Image analysis for the detection and quantification of concrete bugholes in a tunnel lining

Directory of Open Access Journals (Sweden)

Isamu Yoshitake

2018-06-01

Full Text Available A measurement and quantification system for concrete bugholes (surface air voids on sidewalls was developed to quantify the surface quality of tunnel-lining concrete. The developed system uses and evaluates red/green/blue values of color images taken by a commercial digital still camera. A comparative test shows that the developed system has higher accuracy than image analyses using thresholding and can estimate bugholes with accuracy almost equal to that of a detailed visual inspection. The results confirm that even small bugholes (<1 mm can be detected in color image analysis, whereas such bugholes are hardly detected in the detailed visual survey. In addition, color image analysis improves the calculations of the area of multiple bugholes distributed randomly over a concrete surface. Fundamental tests employing image analysis demonstrate that the prevalence of bugholes increases with an increase in the negative angle of the concrete form and a decrease in concrete workability. The system is applicable to the quantitative evaluation of a concrete surface having visible and invisible bugholes. Results indicate that the developed color image analysis can contribute to the reasonable and appropriate evaluation of bugholes and replace a detailed survey that requires much human resource and has a long inspection time. Keywords: Bughole, Image analysis, Surface quality, Tunnel lining concrete, Laboratory test, Inspection

On-line monitoring of solar cell module production by ellipsometry technique

International Nuclear Information System (INIS)

Fried, M.

2014-01-01

Non-destructive analyzing tools are needed at all stages of thin film photovoltaic (PV) development, and on production lines. In thin film PV, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity (because each elementary cell is connected electrically in series within a big panel) serve as an important starting point in the evaluation of the performance of the cell or module. An important focus is to express the dielectric functions of each component material in terms of a handful of wavelength independent parameters whose variation can cover all process variants of that material. With the resulting database, spectroscopic ellipsometry coupled with multilayer analysis can be developed for on-line point-by-point mapping and on-line line-by-line imaging. This work tries to review the investigations of different types of PV-layers (anti-reflective coating, transparent-conductive oxide (TCO), multi-diode-structure, absorber and window layers) showing the existing dielectric function databases for the thin film components of CdTe, CuInGaSe 2 , thin Si, and TCO layers. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels in developing labs but it is slow in the on-line mode when only 15 points can be obtained (within 1 min) as a 120 cm long panel moves by the mapping station. In the last years [M. Fried et al., Thin Solid Films 519, 2730 (2011)], instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl = 350–1000 nm) data. Up to now a single 30 point line image can be collected in 10 s over a 15 cm width of PV material. This year we are building a 30 and a 60 cm width expanded beam ellipsometer the speed of which will be increased by 10 ×. Then 1800 points can be mapped in a 1 min traverse of a 60 ∗ 120 cm PV panel or flexible roll-to-roll substrate. - Highlights: • Instrumentation developed provides a line image of

On-line monitoring of solar cell module production by ellipsometry technique

Energy Technology Data Exchange (ETDEWEB)

Fried, M., E-mail: fried@mfa.kfki.hu

2014-11-28

Non-destructive analyzing tools are needed at all stages of thin film photovoltaic (PV) development, and on production lines. In thin film PV, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity (because each elementary cell is connected electrically in series within a big panel) serve as an important starting point in the evaluation of the performance of the cell or module. An important focus is to express the dielectric functions of each component material in terms of a handful of wavelength independent parameters whose variation can cover all process variants of that material. With the resulting database, spectroscopic ellipsometry coupled with multilayer analysis can be developed for on-line point-by-point mapping and on-line line-by-line imaging. This work tries to review the investigations of different types of PV-layers (anti-reflective coating, transparent-conductive oxide (TCO), multi-diode-structure, absorber and window layers) showing the existing dielectric function databases for the thin film components of CdTe, CuInGaSe{sub 2}, thin Si, and TCO layers. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels in developing labs but it is slow in the on-line mode when only 15 points can be obtained (within 1 min) as a 120 cm long panel moves by the mapping station. In the last years [M. Fried et al., Thin Solid Films 519, 2730 (2011)], instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl = 350–1000 nm) data. Up to now a single 30 point line image can be collected in 10 s over a 15 cm width of PV material. This year we are building a 30 and a 60 cm width expanded beam ellipsometer the speed of which will be increased by 10 ×. Then 1800 points can be mapped in a 1 min traverse of a 60 ∗ 120 cm PV panel or flexible roll-to-roll substrate. - Highlights: • Instrumentation developed provides a line image of

SU-E-J-24: Image-Guidance Using Cone-Beam CT for Stereotactic Body Radiotherapy (SBRT) of Lung Cancer Patients: Bony Alignment or Soft Tissue Alignment?

Science.gov (United States)

Wang, L; Turaka, A; Meyer, J; Spoka, D; Jin, L; Fan, J; Ma, C

2012-06-01

To assess the reliability of soft tissue alignment by comparing pre- and post-treatment cone-beam CT (CBCT) for image guidance in stereotactic body radiotherapy (SBRT) of lung cancers. Our lung SBRT procedures require all patients undergo 4D CT scan in order to obtain patient-specific target motion information through reconstructed 4D data using the maximum-intensity projection (MIP) algorithm. The internal target volume (ITV) was outlined directly from the MIP images and a 3-5 mm margin expansion was then applied to the ITV to create the PTV. Conformal treatment planning was performed on the helical images, to which the MIP images were fused. Prior to each treatment, CBCT was used for image guidance by comparing with the simulation CT and for patient relocalization based on the bony anatomy. Any displacement of the patient bony structure would be considered as setup errors and would be corrected by couch shifts. Theoretically, as the PTV definition included target internal motion, no further shifts other than setup corrections should be made. However, it is our practice to have treating physicians further check target localization within the PTV. Whenever the shifts based on the soft-tissue alignment (that is, target alignment) exceeded a certain value (e.g. 5 mm), a post-treatment CBCT was carried out to ensure that the tissue alignment is reliable by comparing between pre- and post-treatment CBCT. Pre- and post-CBCT has been performed for 7 patients so far who had shifts beyond 5 mm despite bony alignment. For all patients, post CBCT confirmed that the visualized target position was kept in the same position as before treatment after adjusting for soft-tissue alignment. For the patient population studied, it is shown that soft-tissue alignment is necessary and reliable in the lung SBRT for individual cases. © 2012 American Association of Physicists in Medicine.

CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

Energy Technology Data Exchange (ETDEWEB)

Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Wang, Junfeng [Department of Astronomy, Physics Building, Xiamen University Xiamen, Fujian, 361005 (China); Storchi-Bergmann, Thaisa, E-mail: walter.maksym@cfa.harvard.edu [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, IF, CP 15051, 91501-970 Porto Alegre, RS (Brazil)

2017-07-20

The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra 's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O iii], [S ii], and H α , as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ∼10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include H α evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

Science.gov (United States)

Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John; Wang, Junfeng; Storchi-Bergmann, Thaisa

2017-07-01

The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O III], [S II], and Hα, as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ˜10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include Hα evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

International Nuclear Information System (INIS)

Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John; Wang, Junfeng; Storchi-Bergmann, Thaisa

2017-01-01

The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra 's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O iii], [S ii], and H α , as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ∼10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include H α evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

Evaluation of an improved technique for automated center lumen line definition in cardiovascular image data

International Nuclear Information System (INIS)

Gratama van Andel, Hugo A.F.; Meijering, Erik; Vrooman, Henri A.; Stokking, Rik; Lugt, Aad van der; Monye, Cecile de

2006-01-01

The aim of the study was to evaluate a new method for automated definition of a center lumen line in vessels in cardiovascular image data. This method, called VAMPIRE, is based on improved detection of vessel-like structures. A multiobserver evaluation study was conducted involving 40 tracings in clinical CTA data of carotid arteries to compare VAMPIRE with an established technique. This comparison showed that VAMPIRE yields considerably more successful tracings and improved handling of stenosis, calcifications, multiple vessels, and nearby bone structures. We conclude that VAMPIRE is highly suitable for automated definition of center lumen lines in vessels in cardiovascular image data. (orig.)

Hybrid phase retrieval algorithm for solving the twin image problem in in-line digital holography

Science.gov (United States)

Zhao, Jie; Wang, Dayong; Zhang, Fucai; Wang, Yunxin

2010-10-01

For the reconstruction in the in-line digital holography, there are three terms overlapping with each other on the image plane, named the zero order term, the real image and the twin image respectively. The unwanted twin image degrades the real image seriously. A hybrid phase retrieval algorithm is presented to address this problem, which combines the advantages of two popular phase retrieval algorithms. One is the improved version of the universal iterative algorithm (UIA), called the phase flipping-based UIA (PFB-UIA). The key point of this algorithm is to flip the phase of the object iteratively. It is proved that the PFB-UIA is able to find the support of the complicated object. Another one is the Fienup algorithm, which is a kind of well-developed algorithm and uses the support of the object as the constraint among the iteration procedure. Thus, by following the Fienup algorithm immediately after the PFB-UIA, it is possible to produce the amplitude and the phase distributions of the object with high fidelity. The primary simulated results showed that the proposed algorithm is powerful for solving the twin image problem in the in-line digital holography.

The potential role of respiratory motion management and image guidance in the reduction of severe toxicities following stereotactic ablative radiation therapy for patients with centrally located early stage non-small cell lung cancer or lung metastases

Directory of Open Access Journals (Sweden)

Alexander eChi

2014-06-01

Full Text Available Image guidance allows delivery of very high doses of radiation over a few fractions, known as stereotactic ablative radiotherapy (SABR. This treatment is associated with excellent outcome for early stage non-small cell lung cancer and metastases to the lungs. In the delivery of SABR, central location constantly poses a challenge due to the difficulty of adequately sparing critical thoracic structures that are immediately adjacent to the tumor if an ablative dose of radiation is to be delivered to the tumor target. As of current, various respiratory motion management and image guidance strategies can be used to ensure accurate tumor target localization prior and/ or during daily treatment, which allows for maximal and safe reduction of set up margins. The incorporation of both may lead to the most optimal normal tissue sparing and the most accurate SABR delivery. Here, the clinical outcome, treatment related toxicities, and the pertinent respiratory motion management/image guidance strategies reported in the current literature on SABR for central lung tumors are reviewed.

The Design of a Modified PSO Guidance Law Using Predictor and LOS Rate Evaluation

Directory of Open Access Journals (Sweden)

Lee Yung-Lung

2016-01-01

Full Text Available This paper proposes a modified particle swarm optimization guidance (MPSOG for the pursuit-evasion optimization problem. If the line-of-sight (LOS rate equals zero, the curvature of the missile’s trajectory would be smaller and the probability of intercept greater. Thus, we propose using a MPSOG to improve the guidance performance. The MPSOG uses a Kalman filter to predict a target’s dynamic. The lateral acceleration commands of the y- and z-axis are optimized by the particle swarm optimization (PSO algorithm, respectively. Numerical simulation results show that the MPSOG have better guidance performance than proportional navigation guidance and particle swarm optimization guidance in miss distance, time-to-go, and final lateral acceleration commands.

Impact of connected vehicle guidance information on network-wide average travel time

Directory of Open Access Journals (Sweden)

Jiangfeng Wang

2016-12-01

Full Text Available With the emergence of connected vehicle technologies, the potential positive impact of connected vehicle guidance on mobility has become a research hotspot by data exchange among vehicles, infrastructure, and mobile devices. This study is focused on micro-modeling and quantitatively evaluating the impact of connected vehicle guidance on network-wide travel time by introducing various affecting factors. To evaluate the benefits of connected vehicle guidance, a simulation architecture based on one engine is proposed representing the connected vehicle–enabled virtual world, and connected vehicle route guidance scenario is established through the development of communication agent and intelligent transportation systems agents using connected vehicle application programming interface considering the communication properties, such as path loss and transmission power. The impact of connected vehicle guidance on network-wide travel time is analyzed by comparing with non-connected vehicle guidance in response to different market penetration rate, following rate, and congestion level. The simulation results explore that average network-wide travel time in connected vehicle guidance shows a significant reduction versus that in non–connected vehicle guidance. Average network-wide travel time in connected vehicle guidance have an increase of 42.23% comparing to that in non-connected vehicle guidance, and average travel time variability (represented by the coefficient of variance increases as the travel time increases. Other vital findings include that higher penetration rate and following rate generate bigger savings of average network-wide travel time. The savings of average network-wide travel time increase from 17% to 38% according to different congestion levels, and savings of average travel time in more serious congestion have a more obvious improvement for the same penetration rate or following rate.

Tailoring four-dimensional cone-beam CT acquisition settings for fiducial marker-based image guidance in radiation therapy.

Science.gov (United States)

Jin, Peng; van Wieringen, Niek; Hulshof, Maarten C C M; Bel, Arjan; Alderliesten, Tanja

2018-04-01

Use of four-dimensional cone-beam CT (4D-CBCT) and fiducial markers for image guidance during radiation therapy (RT) of mobile tumors is challenging due to the trade-off among image quality, imaging dose, and scanning time. This study aimed to investigate different 4D-CBCT acquisition settings for good visibility of fiducial markers in 4D-CBCT. Using these 4D-CBCTs, the feasibility of marker-based 4D registration for RT setup verification and manual respiration-induced motion quantification was investigated. For this, we applied a dynamic phantom with three different breathing motion amplitudes and included two patients with implanted markers. Irrespective of the motion amplitude, for a medium field of view (FOV), marker visibility was improved by reducing the imaging dose per projection and increasing the number of projection images; however, the scanning time was 4 to 8 min. For a small FOV, the total imaging dose and the scanning time were reduced (62.5% of the dose using a medium FOV, 2.5 min) without losing marker visibility. However, the body contour could be missing for a small FOV, which is not preferred in RT. The marker-based 4D setup verification was feasible for both the phantom and patient data. Moreover, manual marker motion quantification can achieve a high accuracy with a mean error of [Formula: see text].

Effects of line fiducial parameters and beamforming on ultrasound calibration.

Science.gov (United States)

Ameri, Golafsoun; Baxter, John S H; McLeod, A Jonathan; Peters, Terry M; Chen, Elvis C S

2017-01-01

Ultrasound (US)-guided interventions are often enhanced via integration with an augmented reality environment, a necessary component of which is US calibration. Calibration requires the segmentation of fiducials, i.e., a phantom, in US images. Fiducial localization error (FLE) can decrease US calibration accuracy, which fundamentally affects the total accuracy of the interventional guidance system. Here, we investigate the effects of US image reconstruction techniques as well as phantom material and geometry on US calibration. It was shown that the FLE was reduced by 29% with synthetic transmit aperture imaging compared with conventional B-mode imaging in a Z-bar calibration, resulting in a 10% reduction of calibration error. In addition, an evaluation of a variety of calibration phantoms with different geometrical and material properties was performed. The phantoms included braided wire, plastic straws, and polyvinyl alcohol cryogel tubes with different diameters. It was shown that these properties have a significant effect on calibration error, which is a variable based on US beamforming techniques. These results would have important implications for calibration procedures and their feasibility in the context of image-guided procedures.

Demonstration of a time-integrated short line of sight neutron imaging system for inertial confinement fusion

Energy Technology Data Exchange (ETDEWEB)

Simpson, R., E-mail: raspberry@lanl.gov; Danly, C.; Fatherley, V. E.; Merrill, F. E.; Volegov, P.; Wilde, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Christensen, K.; Fittinghoff, D.; Grim, G. P.; Izumi, N.; Jedlovec, D.; Skulina, K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2015-12-15

The Neutron Imaging System (NIS) is an important diagnostic for understanding implosions of deuterium-tritium capsules at the National Ignition Facility. While the detectors for the existing system must be positioned 28 m from the source to produce sufficient imaging magnification and resolution, recent testing of a new short line of sight neutron imaging system has shown sufficient resolution to allow reconstruction of the source image with quality similar to that of the existing NIS on a 11.6 m line of sight. The new system used the existing pinhole aperture array and a stack of detectors composed of 2 mm thick high-density polyethylene converter material followed by an image plate. In these detectors, neutrons enter the converter material and interact with protons, which recoil and deposit energy within the thin active layer of the image plate through ionization losses. The described system produces time-integrated images for all neutron energies passing through the pinhole. We present details of the measurement scheme for this novel technique to produce energy-integrated neutron images as well as source reconstruction results from recent experiments at NIF.

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography

Energy Technology Data Exchange (ETDEWEB)

Guildenbecher, Daniel Robert; Munz, Elise Dahnke; Farias, Paul Abraham; Thurow, Brian S [Auburn U

2015-12-01

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.

Balloon pulmonary angioplasty: applicability of C-Arm CT for procedure guidance

Energy Technology Data Exchange (ETDEWEB)

Hinrichs, Jan B. [Department for Diagnostic and Interventional Radiology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany); Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover (Germany); Renne, Julius; Wacker, Frank K.; Meyer, Bernhard C. [Department for Diagnostic and Interventional Radiology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany); Hoeper, Marius M.; Olsson, Karen M. [Clinic for Pneumology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany)

2016-11-15

To investigate the feasibility of and compare two C-Arm CT (CACT) guidance methods during balloon pulmonary angioplasty (BPA). Forty-two BPAs [27 CTEPH patients (nine males, 70 ± 14y)] targeting 143 pulmonary arteries were included. Twenty-two BPAs were guided by contrast-enhanced CACT acquired immediately before BPA (G3D). In another 20 BPAs (G2D), two orthogonal fluoroscopy images of the chest where acquired to compute a registration of a previously acquired CACT. Volume rendering-based graphic representations (VRT guidance) were generated indicating the origin and course of the vessels. Based on VRT guidance, the intervention was planned. Procedure durations and radiation exposure data were compared between the two groups (Wilcoxon test). The overall intervention time was approximately 2 h in both groups (p = 0.31). BPA was successfully performed in G3D 91 % and G2D 94 %. No significant difference was found concerning the mean dose area product (DAP) related to fluoroscopy (p = 0.38), while DAP related to DSA was slightly higher in G3D (p = 0.048). Overall, DAP was significantly higher in G3D (p = 0.002). The use of CACT for procedure guidance in patients undergoing BPA is feasible and accurate. Image fusion of a pre-acquired CACT can be used to decrease radiation exposure due to multiple BPA sessions. (orig.)

Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke

International Nuclear Information System (INIS)

Buckley, B.T.; Wainwright, A.; Meagher, T.; Briley, D.

2003-01-01

AIM: To audit the feasibility and use of diffusion-weighted (DW) magnetic resonance imaging (MRI) as initial neuroimaging for in-patients with clinically suspected acute stroke. MATERIALS AND METHODS: In April 2000, MRI with DW and T2-weighted sequence was locally instituted as initial neuroimaging for patients with clinically suspected acute stroke. This retrospective study reviewed imaging performed for in-patients with suspected acute stroke over a 9-month period. Data were collected on image type, result and need for repeat imaging. RESULTS: During the study period, 124 patients had neuroimaging for suspected cerebrovascular accident, and 119 were MRI safe. Eighty-eight (73.9%) patients underwent DW MRI as first-line investigation. Five patients were not MRI safe and 31 had computed tomography (CT) as first-line imaging due to lack of available MRI capacity. Repeat neuroimaging was performed in 16 (12.9%) patients. Study times were comparable for both types of neuroimaging: a mean of 13 min for MRI and 11 min for CT. CONCLUSION: The audit standard was achieved in 88 (73.9%) patients. The use of DW MRI as a first-line investigation for patients with a clinical diagnosis of acute stroke is achievable in a district general hospital setting

Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke

Energy Technology Data Exchange (ETDEWEB)

Buckley, B.T.; Wainwright, A.; Meagher, T.; Briley, D

2003-03-01

AIM: To audit the feasibility and use of diffusion-weighted (DW) magnetic resonance imaging (MRI) as initial neuroimaging for in-patients with clinically suspected acute stroke. MATERIALS AND METHODS: In April 2000, MRI with DW and T2-weighted sequence was locally instituted as initial neuroimaging for patients with clinically suspected acute stroke. This retrospective study reviewed imaging performed for in-patients with suspected acute stroke over a 9-month period. Data were collected on image type, result and need for repeat imaging. RESULTS: During the study period, 124 patients had neuroimaging for suspected cerebrovascular accident, and 119 were MRI safe. Eighty-eight (73.9%) patients underwent DW MRI as first-line investigation. Five patients were not MRI safe and 31 had computed tomography (CT) as first-line imaging due to lack of available MRI capacity. Repeat neuroimaging was performed in 16 (12.9%) patients. Study times were comparable for both types of neuroimaging: a mean of 13 min for MRI and 11 min for CT. CONCLUSION: The audit standard was achieved in 88 (73.9%) patients. The use of DW MRI as a first-line investigation for patients with a clinical diagnosis of acute stroke is achievable in a district general hospital setting.

Usefulness of MR coronal imaging of the ''pyramidal line''. Predictive value in motor function of stroke patients

International Nuclear Information System (INIS)

Satoh, Kenichi; Matsuzaki, Takayuki; Shimazaki, Mitsunori

1997-01-01

A coronal image was obtained along a straight line between the front edge of the medulla and the deepest point of the interpeduncular cistern in the midsagittal plane (the ''pyramidal line''). This coronal image along the pyramidal line revealed the pyramidal tract extending from the internal capsule down to the medulla. Using this technique, we studied 25 patients with motor deficit associated with cerebrovascular disease. We predicted the possibility of their recovery in the subacute stage. We were able to predict the recovery in 23 patients (92%). We conclude that a coronal image along the pyramidal line is useful for the understanding of relation between pyramidal tract and lesion and for predicting motor function. (author)

Usefulness of MR coronal imaging of the ``pyramidal line``. Predictive value in motor function of stroke patients

Energy Technology Data Exchange (ETDEWEB)

Satoh, Kenichi; Matsuzaki, Takayuki; Shimazaki, Mitsunori [Hakodate Red Cross Hospital, Hokkaido (Japan)

1997-06-01

A coronal image was obtained along a straight line between the front edge of the medulla and the deepest point of the interpeduncular cistern in the midsagittal plane (the ``pyramidal line``). This coronal image along the pyramidal line revealed the pyramidal tract extending from the internal capsule down to the medulla. Using this technique, we studied 25 patients with motor deficit associated with cerebrovascular disease. We predicted the possibility of their recovery in the subacute stage. We were able to predict the recovery in 23 patients (92%). We conclude that a coronal image along the pyramidal line is useful for the understanding of relation between pyramidal tract and lesion and for predicting motor function. (author)

International Conference on Harmonisation; guidance on Q9 Quality Risk Management; availability. Notice.

Science.gov (United States)

2006-06-02

The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "Q9 Quality Risk Management."' The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance provides principles and examples of tools for quality risk management that can be applied to all aspects of pharmaceutical quality throughout the lifecycle of drug substances, drug products, and biological and biotechnological products. The guidance is intended to enable regulators and industry to make more effective and consistent risk-based decisions.

In-line X-ray lensless imaging with lithium fluoride film detectors

International Nuclear Information System (INIS)

Bonfigli, F.; Cecilia, A.; Bateni, S. Heidari; Nichelatti, E.; Pelliccia, D.; Somma, F.; Vagovic, P.; Vincenti, M.A.; Baumbach, T.; Montereali, R.M.

2013-01-01

In this work, we present preliminary in-line X-ray lensless projection imaging results at a synchrotron facility by using novel solid-state detectors based on non-destructive readout of photoluminescent colour centres in lithium fluoride thin films. The peculiarities of LiF radiation detectors are high spatial resolution on a large field of view, wide dynamic range, versatility and simplicity of use. These properties offered the opportunity to test a broadband X-ray synchrotron source for lensless projection imaging experiments at the TopoTomo beamline of the ANKA synchrotron facility by using a white beam spectrum (3–40 keV). Edge-enhancement effects were observed for the first time on a test object; they are discussed and compared with simulations, on the basis of the colour centre photoluminescence linear response found in the investigated irradiation conditions. -- Highlights: ► We performed broadband X-ray imaging at synchrotron by novel LiF imaging detectors. ► X-ray phase contrast experiments on LiF crystals and thin films were performed. ► Photoluminescent high-quality X-images on a LiF film only 1 μm thick were obtained. ► Edge-enhancement effects were detected and compared with simulations. ► A linearity of colour centre fluorescence response of LiF film was found

Ultrasound and PET-CT image fusion for prostate brachytherapy image guidance

International Nuclear Information System (INIS)

Hasford, F.

2015-01-01

, indicating the system’s ability to visualize low contrast objects 5.4 cm into a patient. PET-CT system’s performance evaluation also produced satisfactory results in accordance with set tolerances as recommended by IAEA Human Health Series 1. Computed tomography laser alignment test ensured that all CT gantry lasers were properly aligned with the patient bed. Image display width test ensured that volume of patient or organ being measured and displayed was equivalent to that selected on the CT scanner console, to a deviation of ± 1 mm. Results from CT image uniformity test showed that mean CT numbers in peripheral regions of interest deviated from the central mean to within recommended tolerance level of ± 5 HU, indicating a good level of uniformity. Computed tomographic dose indices for head and body phantoms were estimated as 44.30 mGy and 20.08 mGy, comparative to console displayed doses of 42.40 mGy and 19.49 mGy respectively. Registration accuracy for PET-CT images was to have displacements of less than 1 mm in x, y and z directions. Image quality of PET-CT images was performed to produce images simulating those obtained in a total body imaging study involving both hot and cold lesions. Percentage contrast estimates of 49.3% and 52.6% were obtained for hot spheres of diameters 1.3 cm and 2.2 cm respectively, while contrast estimates of 74.8% and 75.6% were obtained for cold spheres of diameters 2.8 cm and 3.7 cm respectively. The PET-CT system resolution was estimated as 0.5 ± 0.01 cm, indicating the system’s ability to image tumours of the size of about 5 mm. Satisfactory results from the performance evaluation of ultrasound and PET-CT systems, paved way for them to be used in acquiring prostatic images for the study. Developed MATLAB image enhancement algorithm enhanced the quality of prostatic images before fusion. The algorithm was developed by mapping the intensity values in raw images to new values in a modified image using imadjust function. Contrast

Rapid and sensitive phenotypic marker detection on breast cancer cells using surface-enhanced Raman scattering (SERS) imaging.

Science.gov (United States)

Lee, Sangyeop; Chon, Hyangah; Lee, Jiyoung; Ko, Juhui; Chung, Bong Hyun; Lim, Dong Woo; Choo, Jaebum

2014-01-15

We report a surface-enhanced Raman scattering (SERS)-based cellular imaging technique to detect and quantify breast cancer phenotypic markers expressed on cell surfaces. This technique involves the synthesis of SERS nano tags consisting of silica-encapsulated hollow gold nanospheres (SEHGNs) conjugated with specific antibodies. Hollow gold nanospheres (HGNs) enhance SERS signal intensity of individual particles by localizing surface electromagnetic fields through pinholes in the hollow particle structures. This capacity to enhance imaging at the level of single molecules permits the use of HGNs to detect specific biological markers expressed in living cancer cells. In addition, silica encapsulation greatly enhances the stability of nanoparticles. Here we applied a SERS-based imaging technique using SEHGNs in the multiplex imaging of three breast cancer cell phenotypes. Expression of epidermal growth factor (EGF), ErbB2, and insulin-like growth factor-1 (IGF-1) receptors were assessed in the MDA-MB-468, KPL4 and SK-BR-3 human breast cancer cell lines. SERS imaging technology described here can be used to test the phenotype of a cancer cell and quantify proteins expressed on the cell surface simultaneously. Based on results, this technique may enable an earlier diagnosis of breast cancer than is currently possible and offer guidance in treatment. © 2013 Elsevier B.V. All rights reserved.

Use of deformed intensity distributions for on-line modification of image-guided IMRT to account for interfractional anatomic changes

International Nuclear Information System (INIS)

Mohan, Radhe; Zhang Xiaodong; Wang He; Kang Yixiu; Wang Xiaochun; Liu, Helen; Ang, K.; Kuban, Deborah; Dong Lei

2005-01-01

Purpose: Recent imaging studies have demonstrated that there can be significant changes in anatomy from day to day and over the course of radiotherapy as a result of daily positioning uncertainties and physiologic and clinical factors. There are a number of strategies to minimize such changes, reduce their impact, or correct for them. Measures to date have included improved immobilization of external and internal anatomy or adjustment of positions based on portal or ultrasound images. Perhaps the most accurate way is to use CT image-guided radiotherapy, for which the possibilities range from simple correction of setup based on daily CT images to on-line near real-time intensity modulated radiotherapy (IMRT) replanning. In addition, there are numerous intermediate possibilities. In this paper, we report the development of one such intermediate method that takes into account anatomic changes by deforming the intensity distributions of each beam based on deformations of anatomy as seen in the beam's-eye-view. Methods and materials: The intensity distribution deformations are computed based on anatomy deformations discerned from the changes in the current image relative to a reference image (e.g., the pretreatment CT scan). First, a reference IMRT plan is generated based on the reference CT image. A new CT image is acquired using an in-room CT for every fraction. The anatomic structure contours are obtained for the new image. (For this article, these contours were manually drawn. When image guided IMRT methods are implemented, anatomic structure contours on subsequent images will likely be obtained with automatic or semiautomatic means. This could be achieved by, for example, first deforming the original CT image to match today's image, and then using the same deformation transformation to map original contours to today's image.) The reference intensity distributions for each beam are then deformed so that the projected geometric relationship within the beam

Enhanced Visualization of Fine Needles Under Sonographic Guidance Using a MEMS Actuator

Directory of Open Access Journals (Sweden)

Zhiyuan Shen

2015-01-01

Full Text Available Localization of a needle tip is important for biopsy examinations in clinics. However, the needle tip is sometimes difficult to discern under the guidance of sonography due to its poor visibility. A mini actuator that radiates a low-intensity ultrasound wave was manufactured using micro-electro-mechanical system (MEMS technology. Interference between the radiated and diagnostic ultrasound pulses was observed as bright lines in the B-mode ultrasound image, from which the mini actuator could be recognized with ease. Because the distance between the mini actuator and the needle tip is fixed, the needle tip can be determined despite its inconsistent appearance in the sonography. Both gel phantom and ex vivo tissue evaluation showed that the needle tip can be determined reliably utilizing the acoustic interference pattern.

Configuration management: Phase II implementation guidance

Energy Technology Data Exchange (ETDEWEB)

1994-03-01

Configuration management (CM) is essential to maintaining an acceptable level of risk to the public, workers, environment, or mission success. It is a set of activities and techniques used to maintain consistency among physical and functional configuration, applicable requirements, and key documents. This document provides guidance for continuing the implementation of CM in a phased and graded manner. It describes a cost-effective approach to documented consistency with requirements, with early emphasis on items most important to safety and environmental protection. It is intended to help responsible line managers and configuration management staff personnel in meeting the Energy Systems configuration management policy standard.

Partition calculation for zero-order and conjugate image removal in digital in-line holography.

Science.gov (United States)

Ma, Lihong; Wang, Hui; Li, Yong; Jin, Hongzhen

2012-01-16

Conventional digital in-line holography requires at least two phase-shifting holograms to reconstruct an original object without zero-order and conjugate image noise. We present a novel approach in which only one in-line hologram and two intensity values (namely the object wave intensity and the reference wave intensity) are required. First, by subtracting the two intensity values the zero-order diffraction can be completely eliminated. Then, an algorithm, called partition calculation, is proposed to numerically remove the conjugate image. A preliminary experimental result is given to confirm the proposed method. The method can simplify the procedure of phase-shifting digital holography and improve the practical feasibility for digital in-line holography.

Determining fast orientation changes of multi-spectral line cameras from the primary images

Science.gov (United States)

Wohlfeil, Jürgen

2012-01-01

Fast orientation changes of airborne and spaceborne line cameras cannot always be avoided. In such cases it is essential to measure them with high accuracy to ensure a good quality of the resulting imagery products. Several approaches exist to support the orientation measurement by using optical information received through the main objective/telescope. In this article an approach is proposed that allows the determination of non-systematic orientation changes between every captured line. It does not require any additional camera hardware or onboard processing capabilities but the payload images and a rough estimate of the camera's trajectory. The approach takes advantage of the typical geometry of multi-spectral line cameras with a set of linear sensor arrays for different spectral bands on the focal plane. First, homologous points are detected within the heavily distorted images of different spectral bands. With their help a connected network of geometrical correspondences can be built up. This network is used to calculate the orientation changes of the camera with the temporal and angular resolution of the camera. The approach was tested with an extensive set of aerial surveys covering a wide range of different conditions and achieved precise and reliable results.

Fast kilovoltage/megavoltage (kVMV) breathhold cone-beam CT for image-guided radiotherapy of lung cancer

International Nuclear Information System (INIS)

Wertz, Hansjoerg; Stsepankou, Dzmitry; Blessing, Manuel; Boda-Heggemann, Judit; Hesser, Juergen; Lohr, Frank; Wenz, Frederik; Rossi, Michael; Gros, Uwe; Knox, Chris; Brown, Kevin; Walter, Cornelia

2010-01-01

Long image acquisition times of 60-120 s for cone-beam CT (CBCT) limit the number of patients with lung cancer who can undergo volume image guidance under breathhold. We developed a low-dose dual-energy kilovoltage-megavoltage-cone-beam CT (kVMV-CBCT) based on a clinical treatment unit reducing imaging time to ≤15 s. Simultaneous kVMV-imaging was achieved by dedicated synchronization hardware controlling the output of the linear accelerator (linac) based on detector panel readout signals, preventing imaging artifacts from interference of the linac's MV-irradiation and panel readouts. Optimization was performed to minimize the imaging dose. Single MV-projections, reconstructed MV-CBCT images and images of simultaneous 90 0 kV- and 90 0 MV-CBCT (180 0 kVMV-CBCT) were acquired with different parameters. Image quality and imaging dose were evaluated and compared to kV-imaging. Hardware-based kVMV synchronization resulted in artifact-free projections. A combined 180 0 kVMV-CBCT scan with a total MV-dose of 5 monitor units was acquired in 15 s and with sufficient image quality. The resolution was 5-6 line pairs cm -1 (Catphan phantom). The combined kVMV-scan dose was equivalent to a kV-radiation scan dose of ∼33 mGy. kVMV-CBCT based on a standard linac is promising and can provide ultra-fast online volume image guidance with low imaging dose and sufficient image quality for fast and accurate patient positioning for patients with lung cancer under breathhold.

Fusion Guidance in Endovascular Peripheral Artery Interventions: A Feasibility Study

Energy Technology Data Exchange (ETDEWEB)

Sailer, Anna M., E-mail: anni.sailer@mumc.nl; Haan, Michiel W. de, E-mail: m.de.haan@mumc.nl; Graaf, Rick de, E-mail: r.de.graaf@mumc.nl; Zwam, Willem H. van, E-mail: w.van.zwam@mumc.nl [Maastricht University Medical Center, Department of Radiology (Netherlands); Schurink, Geert Willem H., E-mail: gwh.schurink@mumc.nl [Maastricht University Medical Center, Department of Surgery (Netherlands); Nelemans, Patricia J., E-mail: patty.nelemans@maastrichtuniversity.nl [Maastricht University Medical Centre, Department of Epidemiology (Netherlands); Wildberger, Joachim E., E-mail: j.wildberger@mumc.nl; Das, Marco, E-mail: m.das@mumc.nl [Maastricht University Medical Center, Department of Radiology (Netherlands)

2015-04-15

PurposeThis study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA).MethodsFusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography.ResultsAverage time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation).ConclusionsFluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.

Fusion Guidance in Endovascular Peripheral Artery Interventions: A Feasibility Study

International Nuclear Information System (INIS)

Sailer, Anna M.; Haan, Michiel W. de; Graaf, Rick de; Zwam, Willem H. van; Schurink, Geert Willem H.; Nelemans, Patricia J.; Wildberger, Joachim E.; Das, Marco

2015-01-01

PurposeThis study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA).MethodsFusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography.ResultsAverage time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation).ConclusionsFluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety

Assessing mesoscale material response under shock & isentropic compression via high-resolution line-imaging VISAR.

Energy Technology Data Exchange (ETDEWEB)

Hall, Clint Allen; Furnish, Michael David; Podsednik, Jason W.; Reinhart, William Dodd; Trott, Wayne Merle; Mason, Joshua

2003-10-01

Of special promise for providing dynamic mesoscale response data is the line-imaging VISAR, an instrument for providing spatially resolved velocity histories in dynamic experiments. We have prepared two line-imaging VISAR systems capable of spatial resolution in the 10-20 micron range, at the Z and STAR facilities. We have applied this instrument to selected experiments on a compressed gas gun, chosen to provide initial data for several problems of interest, including: (1) pore-collapse in copper (two variations: 70 micron diameter hole in single-crystal copper) and (2) response of a welded joint in dissimilar materials (Ta, Nb) to ramp loading relative to that of a compression joint. The instrument is capable of resolving details such as the volume and collapse history of a collapsing isolated pore.

A semi-automatic method for extracting thin line structures in images as rooted tree network

Energy Technology Data Exchange (ETDEWEB)

Brazzini, Jacopo [Los Alamos National Laboratory; Dillard, Scott [Los Alamos National Laboratory; Soille, Pierre [EC - JRC

2010-01-01

This paper addresses the problem of semi-automatic extraction of line networks in digital images - e.g., road or hydrographic networks in satellite images, blood vessels in medical images, robust. For that purpose, we improve a generic method derived from morphological and hydrological concepts and consisting in minimum cost path estimation and flow simulation. While this approach fully exploits the local contrast and shape of the network, as well as its arborescent nature, we further incorporate local directional information about the structures in the image. Namely, an appropriate anisotropic metric is designed by using both the characteristic features of the target network and the eigen-decomposition of the gradient structure tensor of the image. Following, the geodesic propagation from a given seed with this metric is combined with hydrological operators for overland flow simulation to extract the line network. The algorithm is demonstrated for the extraction of blood vessels in a retina image and of a river network in a satellite image.

Non-cable vehicle guidance

Energy Technology Data Exchange (ETDEWEB)

Daugela, G.C.; Willott, A.M.; Chopiuk, R.G.; Thornton, S.E.

1988-06-01

The purpose is to determine the most promising driverless mine vehicle guidance systems that are not dependent on buried cables, and to plan their development. The project is presented in two phases: a preliminary study and literature review to determine whether suitable technologies exist to justify further work; and an in-depth assessment and selection of technologies for vehicle guidance. A large number of guidance elements are involved in a completely automated vehicle. The technologies that hold the best potential for development of guidance systems for mine vehicles are ultrasonics, radar, lasers, dead reckoning, and guidance algorithms. The best approach to adaptation of these technologies is on a step by step basis. Guidance modules that are complete in themselves and are designed to be integrated with other modules can provide short term benefits. Two modules are selected for development: the dragline operations monitor and automated machine control for optimized mining (AMCOM). 99 refs., 20 figs., 40 tabs.

Evaluation of an in-line particle imaging tool for monitoring twin-screw granulation performance

DEFF Research Database (Denmark)

Kumar, Ashish; Dhondt, Jens; De Leersnyder, Fien

2015-01-01

system. Off-line sieving was used as reference particle size analysis method. A twin-screw granulator which is part of the Consigma system was used to granulate a placebo formulation composed of lactose and polyvinylpyrrolidone (PVP; 97.5:2.5% w/w). PVP was dissolvedin water, which was used......). The volumetric size distribution obtained from the in-line measurements of the granules leaving the twin-screw granulator using the Eyecon™ camera was compared with the off-line measurements obtainedby sieving of the granule samples collected before and after the drying unit operation. For the intermediate size...... range (diameter 250–1000 μm), the Eyecon™ measurements showed to be promising as they were in agreement with off-line measurement results obtained before the drying unit. However, the image analysis algorithm and data post-processing of the Eyecon™ images for the fines and oversized ranges require...

Image-guided radiotherapy and motion management in lung cancer

DEFF Research Database (Denmark)

Korreman, Stine

2015-01-01

In this review, image guidance and motion management in radiotherapy for lung cancer is discussed. Motion characteristics of lung tumours and image guidance techniques to obtain motion information are elaborated. Possibilities for management of image guidance and motion in the various steps...

A Study on the Influence of Teacher's Verbal Guidance on Pupil's Emotional Functions

OpenAIRE

後藤, 靖宏

2006-01-01

How do the pupils accept teachers' words of guidance? The purpose of this paper is to study the influence of teachers' verbal guidance on pupil's consciousness ( of emotions and enthusiasm). Although speech (language) is the fastest method of communication between people, it is not the only means of communication. We usually have two means of communication in human interaction, that is verbal communication and nonverbal communication. This is the same with pupil or student guidance. Nonverbal...

A clinico-radiographic study to compare and co-relate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in completely edentulous patients.

Science.gov (United States)

Shetty, Sanath; Kunta, Mythili; Shenoy, Kamalakanth

2018-01-01

The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in edentulous patients. Twelve completely edentulous patients were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture till jaw relation were carried out. Intraoral gothic arch tracing and protrusive interocclusal records were obtained for each patient. Protrusive interocclusal record was used to program the Hanau Wide-Vue semi-adjustable articulator, thus obtaining the sagittal condylar guidance angle. Using RadiAnt DICOM software, on the orthopantomogram obtained for each patient in the study, two reference lines were drawn. The Frankfort's horizontal plane and the mean curvature line (joining the most superior and the inferior points on the glenoid fossa curvature) were drawn. The mean curvature line was extended to intersect the Frankfort's horizontal plane, thus obtaining the radiographic sagittal condylar guidance angle. The condylar guidance angles obtained by these two methods were compared and subjected to paired t -test. There was no statistically significant difference between the sagittal condylar guidance angles obtained between right and left sides with intraoral gothic arch tracing and radiographic methods ( P = 0.107 and 0.07, respectively). Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used for programming semi-adjustable articulators.

Determination of line edge roughness in low-dose top-down scanning electron microscopy images

NARCIS (Netherlands)

Verduin, T.; Kruit, P.; Hagen, C.W.

2014-01-01

We investigated the off-line metrology for line edge roughness (LER) determination by using the discrete power spectral density (PSD). The study specifically addresses low-dose scanning electron microscopy (SEM) images in order to reduce the acquisition time and the risk of resist shrinkage. The

Comparing the Zeiss Callisto Eye and the Alcon Verion Image Guided System Toric Lens Alignment Technologies.

Science.gov (United States)

Hura, Arjan S; Osher, Robert H

2017-07-01

To compare the alignment meridian generated by the Zeiss Callisto Eye (Carl Zeiss AG, Dublin, CA) and the Alcon Verion Image Guided System (Alcon Laboratories, Inc., Fort Worth, TX). In this retrospective comparative evaluation of technology, intraoperative images were captured at different steps in the same surgery, allowing the comparison of the guidance lines generated by the Verion system to the parallel guidance lines generated by the Callisto Eye system. Measurements of each hemi-meridian were quantified using Adobe Photoshop 2015 CC software (Adobe Systems, San Jose, CA). The numbers of degrees separating these alignment meridians were calculated, entered into a database, and analyzed. The authors found that of 98 captured images of 16 eyes, the two technologies were identical in 0 eyes (θ 1 = θ 2 = 0), similar by 3° in 52 (53%) captured images (θ 1 ≠ θ 2 ≠ 0), and different by at least 3° in 46 (47%) captured images (θ 1 ≠ θ 2 ≠ 0). The target meridians were superimposed, the target lines were minimally separated, and the target lines were dissimilar. It was noted that some intraoperative variation occurred from measurement to measurement. Within the small group of 16 cases of routine toric lens implantation in this study, the absolute average number of degrees of misalignment between the Verion and Callisto Eye systems was 3.355 for θ 1 and 3.838 for θ 2 . On average, the intraoperative variation termed "drift" was noted to be 3.963° for θ 1 , and 4.557° for θ 2 . The authors found that small deviations were frequent when comparing two sophisticated technologies. Although deviations greater than 3° occurred in less than 47% of captured images from 16 eyes, smaller but significant variations of less than 3° occurred in 53% of captured images from 16 eyes. It was rare to identify a large deviation. However, the authors identified "drift" in the same eye when measurements were taken at different times. The results indicate that the two

Imaging of the CO snow line in a solar nebula analog.

Science.gov (United States)

Qi, Chunhua; Öberg, Karin I; Wilner, David J; D'Alessio, Paola; Bergin, Edwin; Andrews, Sean M; Blake, Geoffrey A; Hogerheijde, Michiel R; van Dishoeck, Ewine F

2013-08-09

Planets form in the disks around young stars. Their formation efficiency and composition are intimately linked to the protoplanetary disk locations of "snow lines" of abundant volatiles. We present chemical imaging of the carbon monoxide (CO) snow line in the disk around TW Hya, an analog of the solar nebula, using high spatial and spectral resolution Atacama Large Millimeter/Submillimeter Array observations of diazenylium (N2H(+)), a reactive ion present in large abundance only where CO is frozen out. The N2H(+) emission is distributed in a large ring, with an inner radius that matches CO snow line model predictions. The extracted CO snow line radius of ~30 astronomical units helps to assess models of the formation dynamics of the solar system, when combined with measurements of the bulk composition of planets and comets.

Model simulations of line-of-sight effects in airglow imaging of acoustic and fast gravity waves from ground and space

Science.gov (United States)

Aguilar Guerrero, J.; Snively, J. B.

2017-12-01

Acoustic waves (AWs) have been predicted to be detectable by imaging systems for the OH airglow layer [Snively, GRL, 40, 2013], and have been identified in spectrometer data [Pilger et al., JASP, 104, 2013]. AWs are weak in the mesopause region, but can attain large amplitudes in the F region [Garcia et al., GRL, 40, 2013] and have local impacts on the thermosphere and ionosphere. Similarly, fast GWs, with phase speeds over 100 m/s, may propagate to the thermosphere and impart significant local body forcing [Vadas and Fritts, JASTP, 66, 2004]. Both have been clearly identified in ionospheric total electron content (TEC), such as following the 2013 Moore, OK, EF5 tornado [Nishioka et al., GRL, 40, 2013] and following the 2011 Tohoku-Oki tsunami [e.g., Galvan et al., RS, 47, 2012, and references therein], but AWs have yet to be unambiguously imaged in MLT data and fast GWs have low amplitudes near the threshold of detection; nevertheless, recent imaging systems have sufficient spatial and temporal resolution and sensitivity to detect both AWs and fast GWs with short periods [e.g., Pautet et al., AO, 53, 2014]. The associated detectability challenges are related to the transient nature of their signatures and to systematic challenges due to line-of-sight (LOS) effects such as enhancements and cancelations due to integration along aligned or oblique wavefronts and geometric intensity enhancements. We employ a simulated airglow imager framework that incorporates 2D and 3D emission rate data and performs the necessary LOS integrations for synthetic imaging from ground- and space-based platforms to assess relative intensity and temperature perturbations. We simulate acoustic and fast gravity wave perturbations to the hydroxyl layer from a nonlinear, compressible model [e.g., Snively, 2013] for different idealized and realistic test cases. The results show clear signal enhancements when acoustic waves are imaged off-zenith or off-nadir and the temporal evolution of these

A Dual-Field Sensing Scheme for a Guidance System for the Blind

Directory of Open Access Journals (Sweden)

Qing Lin

2016-05-01

Full Text Available An electronic guidance system is very helpful in improving blind people’s perceptions in a local environment. In our previous work “Lin, Q.; Han, Y. A Context-Aware-Based Audio Guidance System for Blind People Using a Multimodal Profile Model. Sensors 2014, 14, 18670–18700”, a context-aware guidance system using a combination of a laser scanner and a camera was proposed. By using a near-field graphical model, the proposed system could interpret a near-field scene in very high resolution. In this paper, our work is extended by adding a far-field graphical model. The integration of the near-field and the far-field models constitutes a dual-field sensing scheme. In the near-field range, reliable inference of the ground and object status is obtained by fusing range data and image data using the near-field graphical model. In the far-field range, which only the camera can cover, the far-field graphical model is proposed to interpret far-field image data based on appearance and spatial prototypes built using the near-field interpreted data. The dual-field sensing scheme provides a solution for the guidance systems to optimise their scene interpretation capability using simple sensor configurations. Experiments under various local conditions were conducted to show the efficiency of the proposed scheme in improving blind people’s perceptions in urban environments.

75 FR 5356 - Office of New Reactors; Final Interim Staff Guidance on Post-Combined License Commitments

Science.gov (United States)

2010-02-02

... the guidance provided to the NRC staff in Section 1.0, ``Introduction and Interfaces,'' of NUREG-0800, ``Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants,'' concerning the... maintains ADAMS, which provides text and image files of NRC's public documents. These documents may be...

A novel biased proportional navigation guidance law for close approach phase

Directory of Open Access Journals (Sweden)

Su Wenshan

2016-02-01

Full Text Available A novel biased proportional navigation guidance (BPNG law is proposed for the close approach phase, which aims to make the spacecraft rendezvous with the target in specific relative range and direction. Firstly, in order to describe the special guidance requirements, the concept of zero effort miss vector is proposed and the dangerous area where there exists collision risk for safety consideration is defined. Secondly, the BPNG, which decouples the range control and direction control, is designed in the line-of-sight (LOS rotation coordinate system. The theoretical analysis proves that BPNG meets guidance requirements quite well. Thirdly, for the consideration of fuel consumption, the optimal biased proportional navigation guidance (OBPNG law is derived by solving the Schwartz inequality. Finally, simulation results show that BPNG is effective for the close approach with the ability of evading the dangerous area and OBPNG consumes less fuel compared with BPNG.

Improved Debulking of Peritoneal Tumor Implants by Near-Infrared Fluorescent Nanobody Image Guidance in an Experimental Mouse Model.

Science.gov (United States)

Debie, Pieterjan; Vanhoeij, Marian; Poortmans, Natalie; Puttemans, Janik; Gillis, Kris; Devoogdt, Nick; Lahoutte, Tony; Hernot, Sophie

2017-10-31

Debulking followed by combination chemotherapy is currently regarded as the most effective treatment for advanced ovarian cancer. Prognosis depends drastically on the degree of debulking. Accordingly, near-infrared (NIR) fluorescence imaging has been proposed to revolutionize cancer surgery by acting as a sensitive, specific, and real-time tool enabling visualization of cancer lesions. We have previously developed a NIR-labeled nanobody that allows fast, specific, and high-contrast imaging of HER2-positive tumors. In this study, we applied this tracer during fluorescence-guided surgery in a mouse model and investigated the effect on surgical efficiency. 0.5 × 10 6 SKOV3.IP1-Luc+ cells were inoculated intraperitoneally in athymic mice and were allowed to grow for 30 days. Two nanomoles of IRDye800CW-anti-HER2 nanobody was injected intravenously. After 1h30, mice were killed, randomized in two groups, and subjected to surgery. In the first animal group (n = 7), lesions were removed by a conventional surgical protocol, followed by excision of remaining fluorescent tissue using a NIR camera. The second group of mice (n = 6) underwent directly fluorescence-guided surgery. Bioluminescence imaging was performed before and after surgery. Resected tissue was categorized as visualized during conventional surgery or not, fluorescent or not, and bioluminescent positive or negative. Fluorescence imaging allowed clear visualization of tumor nodules within the abdomen, up to submillimeter-sized lesions. Fluorescence guidance resulted in significantly reduced residual tumor as compared to conventional surgery. Moreover, sensitivity increased from 59.3 to 99.0 %, and the percentage of false positive lesions detected decreased from 19.6 to 7.1 %. This study demonstrates the advantage of intraoperative fluorescence imaging using nanobody-based tracers on the efficiency of debulking surgery.

77 FR 69634 - International Conference on Harmonisation; Guidance on Q11 Development and Manufacture of Drug...

Science.gov (United States)

2012-11-20

...] International Conference on Harmonisation; Guidance on Q11 Development and Manufacture of Drug Substances... Administration (FDA) is announcing the availability of a guidance entitled ``Q11 Development and Manufacture of... guidance is intended to apply only to the manufacture of drug substance, not the manufacture of finished...

76 FR 38187 - International Conference on Harmonisation; Draft Guidance on Q11 Development and Manufacture of...

Science.gov (United States)

2011-06-29

...] International Conference on Harmonisation; Draft Guidance on Q11 Development and Manufacture of Drug Substances... Manufacture of Drug Substances.'' The draft guidance was prepared under the auspices of the International... that a draft guidance entitled ``Q11 Development and Manufacture of Drug Substances'' should be made...

Effects of laminin blended with chitosan on axon guidance on patterned substrates

Energy Technology Data Exchange (ETDEWEB)

Zhu, N; Guan, Y J; Chen, X B [Division of Biomedical Engineering, University of Saskatchewan, Saskatoon S7N 5A9 (Canada); Li, M G [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon S7N 5A9 (Canada); Schreyer, D J, E-mail: niz504@mail.usask.c [Department of Anatomy and Cell Biology, Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, S7K 0M7 (Canada)

2010-12-15

Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair.

Effects of laminin blended with chitosan on axon guidance on patterned substrates

International Nuclear Information System (INIS)

Zhu, N; Guan, Y J; Chen, X B; Li, M G; Schreyer, D J

2010-01-01

Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair.

Image quality improvement in megavoltage cone beam CT using an imaging beam line and a sintered pixelated array system

International Nuclear Information System (INIS)

Breitbach, Elizabeth K.; Maltz, Jonathan S.; Gangadharan, Bijumon; Bani-Hashemi, Ali; Anderson, Carryn M.; Bhatia, Sudershan K.; Stiles, Jared; Edwards, Drake S.; Flynn, Ryan T.

2011-01-01

Purpose: To quantify the improvement in megavoltage cone beam computed tomography (MVCBCT) image quality enabled by the combination of a 4.2 MV imaging beam line (IBL) with a carbon electron target and a detector system equipped with a novel sintered pixelated array (SPA) of translucent Gd 2 O 2 S ceramic scintillator. Clinical MVCBCT images are traditionally acquired with the same 6 MV treatment beam line (TBL) that is used for cancer treatment, a standard amorphous Si (a-Si) flat panel imager, and the Kodak Lanex Fast-B (LFB) scintillator. The IBL produces a greater fluence of keV-range photons than the TBL, to which the detector response is more optimal, and the SPA is a more efficient scintillator than the LFB. Methods: A prototype IBL + SPA system was installed on a Siemens Oncor linear accelerator equipped with the MVision TM image guided radiation therapy (IGRT) system. A SPA strip consisting of four neighboring tiles and measuring 40 cm by 10.96 cm in the crossplane and inplane directions, respectively, was installed in the flat panel imager. Head- and pelvis-sized phantom images were acquired at doses ranging from 3 to 60 cGy with three MVCBCT configurations: TBL + LFB, IBL + LFB, and IBL + SPA. Phantom image quality at each dose was quantified using the contrast-to-noise ratio (CNR) and modulation transfer function (MTF) metrics. Head and neck, thoracic, and pelvic (prostate) cancer patients were imaged with the three imaging system configurations at multiple doses ranging from 3 to 15 cGy. The systems were assessed qualitatively from the patient image data. Results: For head and neck and pelvis-sized phantom images, imaging doses of 3 cGy or greater, and relative electron densities of 1.09 and 1.48, the CNR average improvement factors for imaging system change of TBL + LFB to IBL + LFB, IBL + LFB to IBL + SPA, and TBL + LFB to IBL + SPA were 1.63 (p -8 ), 1.64 (p -13 ), 2.66 (p -9 ), respectively. For all imaging doses, soft tissue contrast was more

Quantitative evaluation of a single-distance phase-retrieval method applied on in-line phase-contrast images of a mouse lung

International Nuclear Information System (INIS)

Mohammadi, Sara; Larsson, Emanuel; Alves, Frauke; Dal Monego, Simeone; Biffi, Stefania; Garrovo, Chiara; Lorenzon, Andrea; Tromba, Giuliana; Dullin, Christian

2014-01-01

Quantitative analysis concerning the application of a single-distance phase-retrieval algorithm on in-line phase-contrast images of a mouse lung at different sample-to-detector distances is presented. Propagation-based X-ray phase-contrast computed tomography (PBI) has already proven its potential in a great variety of soft-tissue-related applications including lung imaging. However, the strong edge enhancement, caused by the phase effects, often hampers image segmentation and therefore the quantitative analysis of data sets. Here, the benefits of applying single-distance phase retrieval prior to the three-dimensional reconstruction (PhR) are discussed and quantified compared with three-dimensional reconstructions of conventional PBI data sets in terms of contrast-to-noise ratio (CNR) and preservation of image features. The PhR data sets show more than a tenfold higher CNR and only minor blurring of the edges when compared with PBI in a predominately absorption-based set-up. Accordingly, phase retrieval increases the sensitivity and provides more functionality in computed tomography imaging

77 FR 39498 - Guidances for Industry and Food and Drug Administration Staff: Computer-Assisted Detection...

Science.gov (United States)

2012-07-03

...] Guidances for Industry and Food and Drug Administration Staff: Computer-Assisted Detection Devices Applied... Clinical Performance Assessment: Considerations for Computer-Assisted Detection Devices Applied to... guidance, entitled ``Computer-Assisted Detection Devices Applied to Radiology Images and Radiology Device...

Effects of physical guidance on short-term learning of walking on a narrow beam

OpenAIRE

Domingo, Antoinette; Ferris, Daniel P.

2009-01-01

Physical guidance is often used in rehabilitation when teaching patients to re-learn movements. However, the effects of guidance on motor learning of complex skills, such as walking balance, are not clear. We tested four groups of healthy subjects that practiced walking on a narrow (1.27 cm) or wide (2.5 cm) treadmill-mounted balance beam, with or without physical guidance. Assistance was given by springs attached to a hip belt that applied restoring forces towards beam center. Subjects were ...

Regulatory Guidance for Lightning Protection in Nuclear Power Plants

International Nuclear Information System (INIS)

Kisner, Roger A.; Wilgen, John B.; Ewing, Paul D.; Korsah, Kofi; Antonescu, Christina E.

2006-01-01

Oak Ridge National Laboratory (ORNL) was engaged by the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) to develop the technical basis for regulatory guidance to address design and implementation practices for lightning protection systems in nuclear power plants (NPPs). Lightning protection is becoming increasingly important with the advent of digital and low-voltage analog systems in NPPs. These systems have the potential to be more vulnerable than older analog systems to the resulting power surges and electromagnetic interference (EMI) when lightning strikes facilities or power lines. This paper discusses the technical basis for guidance to licensees and applicants covered in Regulatory Guide (RG) 1.204, Guidelines for Lightning Protection of Nuclear Power Plants, issued August 2005. RG 1.204 describes guidance for practices that are acceptable to the NRC staff for protecting nuclear power structures and systems from direct lightning strikes and the resulting secondary effects.

Guidance and justification in particularistic ethics.

Science.gov (United States)

Kihlbom, U

2000-10-01

This paper argues that, contrary to a common line of criticism followed by scholars such as Helga Kuhse, a particularistic version of virtue ethics properly elaborated, can provide sound moral guidance and a satisfactory account for moral justification of our opinions regarding, for instance, health care practice. In the first part of the paper, three criteria for comparing normative theories with respect to action-guiding power are outlined, and it is argued that the presented particularistic version of virtue ethics actually can provide more guidance than the universalistic theories followed by Kuhse and others. In the second part of the paper it is claimed that universalist normative theories have serious problems accounting for the role that moral principles are supposed to play in the justification, of moral opinions, whereas the present version of virtue ethics accommodates a plausible alternative idea of justification without invoking moral principles or eschewing objectivity.

Magnetic resonance imaging of pelvic floor dysfunction - joint recommendations of the ESUR and ESGAR Pelvic Floor Working Group

International Nuclear Information System (INIS)

El Sayed, Rania Farouk; Alt, Celine D.; Maccioni, Francesca; Meissnitzer, Matthias; Masselli, Gabriele; Manganaro, Lucia; Vinci, Valeria; Weishaupt, Dominik

2017-01-01

To develop recommendations that can be used as guidance for standardized approach regarding indications, patient preparation, sequences acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for diagnosis and grading of pelvic floor dysfunction (PFD). The technique included critical literature between 1993 and 2013 and expert consensus about MRI protocols by the pelvic floor-imaging working group of the European Society of Urogenital Radiology (ESUR) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) from one Egyptian and seven European institutions. Data collection and analysis were achieved in 5 consecutive steps. Eighty-two items were scored to be eligible for further analysis and scaling. Agreement of at least 80 % was defined as consensus finding. Consensus was reached for 88 % of 82 items. Recommended reporting template should include two main sections for measurements and grading. The pubococcygeal line (PCL) is recommended as the reference line to measure pelvic organ prolapse. The recommended grading scheme is the ''Rule of three'' for Pelvic Organ Prolapse (POP), while a rectocele and ARJ descent each has its specific grading system. This literature review and expert consensus recommendations can be used as guidance for MR imaging and reporting of PFD. (orig.)

Impact of NICE guidance on rates of haemorrhage after tonsillectomy: an evaluation of guidance issued during an ongoing national tonsillectomy audit.

Science.gov (United States)

Audit, National Prospective Tonsillectomy

2008-08-01

The National Institute for Health and Clinical Excellence (NICE) issued guidance on surgical techniques for tonsillectomy during a national audit of surgical practice and postoperative complications. To assess the impact of the guidance on tonsillectomy practice and outcomes. An interrupted time-series analysis of routinely collected Hospital Episodes Statistics data, and an analysis of longitudinal trends in surgical technique using data from the National Prospective Tonsillectomy Audit. Patients undergoing tonsillectomy in English NHS hospitals between January 2002 and December 2004. Postoperative haemorrhage within 28 days. The rate of haemorrhage increased by 0.5% per year from 2002, reaching 6.4% when the guidance was published. After publication, the rate of haemorrhage fell immediately to 5.7% (difference 0.7%: 95% CI -1.3% to 0.0%) and the rate of increase appeared to have stopped. Data from the National Prospective Tonsillectomy Audit showed that the fall coincided with a shift in surgical techniques, which was consistent with the guidance. NICE guidance influenced surgical tonsillectomy technique and in turn produced an immediate fall in postoperative haemorrhage. The ongoing national audit and strong support from the surgical specialist association may have aided its implementation.

Investigation of variability in image acquisition and contouring during 3D ultrasound guidance for partial breast irradiation

International Nuclear Information System (INIS)

Landry, Anthony; Olivotto, Ivo; Beckham, Wayne; Berrang, Tanya; Gagne, Isabelle; Popescu, Carmen; Mitchell, Tracy; Vey, Hazel; Sand, Letricia; Soh, Siew Yan; Wark, Jill

2014-01-01

Three-dimensional ultrasound (3DUS) at simulation compared to 3DUS at treatment is an image guidance option for partial breast irradiation (PBI). This study assessed if user dependence in acquiring and contouring 3DUS (operator variability) contributed to variation in seroma shifts calculated for breast IGRT. Eligible patients met breast criteria for current randomized PBI studies. 5 Operators participated in this study. For each patient, 3 operators were involved in scan acquisitions and 5 were involved in contouring. At CT simulation (CT1), a 3DUS (US1) was performed by a single radiation therapist (RT). 7 to 14 days after CT1 a second CT (CT2) and 3 sequential 3DUS scans (US2a,b,c) were acquired by each of 3 RTs. Seroma shifts, between US1 and US2 scans were calculated by comparing geometric centers of the seromas (centroids). Operator contouring variability was determined by comparing 5 RT’s contours for a single image set. Scanning variability was assessed by comparing shifts between multiple scans acquired at the same time point (US1-US2a,b,c). Shifts in seromas contoured on CT (CT1-CT2) were compared to US data. From an initial 28 patients, 15 had CT visible seromas, met PBI dosimetric constraints, had complete US data, and were analyzed. Operator variability contributed more to the overall variability in seroma localization than the variability associated with multiple scan acquisitions (95% confidence mean uncertainty of 6.2 mm vs. 1.1 mm). The mean standard deviation in seroma shift was user dependent and ranged from 1.7 to 2.9 mm. Mean seroma shifts from simulation to treatment were comparable to CT. Variability in shifts due to different users acquiring and contouring 3DUS for PBI guidance were comparable to CT shifts. Substantial inter-observer effect needs to be considered during clinical implementation of 3DUS IGRT

Differences in Brand Image of Online Chat Application of Blackberry Messenger, Whatsapp, and Line for Bina Nusantara University’s Student

Directory of Open Access Journals (Sweden)

Kuspuji C. B. Wicaksono

2016-05-01

Full Text Available This article was written to find out whether there were any differences on brand image for each online chat Application such as Blackberry Messenger, Whatsapp, and LINE based on six factors of the brand image which are: benefits, attributes, cultures, values, personality, and user. Data for the research were collected from questionnaires given to respondents who had used each mention online chat application. Then each respondent was asked to give scores based on the six factors of brand image for each online chat Application. Using the ANOVA method for testing the differences between brand images for each online chat application. The result reveales that there are differences in the brand image between BlackBerry Messenger, Whatsapp, and LINE for benefits, cultures, and values. There is no difference in attributes, and personality cannot be tested. The company that creates online chat application are expected to improve their brand image to distinguish one another differently.

Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega