Semi-automatic construction of reference standards for evaluation of image registration

NARCIS (Netherlands)

Murphy, K.; Ginneken, van B.; Klein, S.; Staring, M.; Hoop, de B.J.; Viergever, M.A.; Pluim, J.P.W.

2011-01-01

Quantitative evaluation of image registration algorithms is a difficult and under-addressed issue due to the lack of a reference standard in most registration problems. In this work a method is presented whereby detailed reference standard data may be constructed in an efficient semi-automatic

9 CFR 201.86 - Brand inspection: Application for authorization, registration and filing of schedules, reciprocal...

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Brand inspection: Application for... STOCKYARDS ACT Inspection of Brands § 201.86 Brand inspection: Application for authorization, registration... in which branding or marking of livestock as a means of establishing ownership prevails by custom or...

Mass preserving image registration

DEFF Research Database (Denmark)

Gorbunova, Vladlena; Sporring, Jon; Lo, Pechin Chien Pau

2010-01-01

The paper presents results the mass preserving image registration method in the Evaluation of Methods for Pulmonary Image Registration 2010 (EMPIRE10) Challenge. The mass preserving image registration algorithm was applied to the 20 image pairs. Registration was evaluated using four different...

Comparison of Authorization/Registration/Notification Processes among Biocidal Products, Cosmetics, Plant Protection Products and Human Medicinal Products

OpenAIRE

Söyleriz, Yüksel

2015-01-01

In this study, comparison of the authorization/registration/notification processes of biocidal products, cosmetics, plant protection products and medicinal products are made and in this respect, the situation in EU is assessed.

Registration quality evaluator: application to automated patient setup verification in radiotherapy

Science.gov (United States)

Wu, Jian; Samant, Sanjiv S.

2004-05-01

An image registration quality evaluator (RQE) is proposed to automatically quantify the accuracy of registrations. The RQE, based on an adaptive pattern classifier, is generated from a pair of reference and target images. It is unique to each patient, anatomical site and imaging modality. RQE is applied to patient positioning in cranial radiotherapy using portal/portal and portal/DRR registrations. We adopted 1mm translation and 1° rotation as the maximal acceptable registration errors, reflecting typical clinical setup tolerances. RQE is used to determine the acceptability of a registration. The performance of RQE was evaluated using phantom images containing radio-opaque fiducial markers. Using receiver operating characteristic (ROC) analysis, we estimated the sensitivity and the specificity of the RQE are 0.95 (with 0.89-0.98 confidence interval (CI) at 95% significance level) and 0.95 (with 0.88-0.98 CI at 95% significance level) respectively for intramodal RQE. For intermodal RQE, the sensitivity and the specificity are 0.92 (with 0.81-0.98 CI at 95% significance level) and 0.98 (with 0.89-0.99 CI at 95% significance level) respectively. Clinical use of RQE could significantly reduce the involvement of the oncologist for routine pre-treatment patient positioning verification, while increasing setup accuracy.

Development and evaluation of automatic registration system for multi-range fiducials applied to augmented reality

International Nuclear Information System (INIS)

Ishii, Hirotake; Yang, Shoufeng; Yan, Weida; Shimoda, Hiroshi; Izumi, Masanori

2009-01-01

In this study, an automatic registration system was developed that can measure 3 dimensional position and orientation of multi-range fiducials automatically using a camera, laser range finder and motion bases connected to a computer. Result of the experimental evaluation shows that the measurement takes about 50 seconds per marker and RMSE (Root Mean Square Error) of the position and orientation measurement are 3.5 mm and 1.2 degrees respectively. (author)

Evaluation of multi-modality CT-MRI-SPECT registration tools for radiotherapy treatment planning purposes

International Nuclear Information System (INIS)

Bianchini, S.; Alfonso, R.; Castillo, J.; Coca, M.; Torres, L.

2013-01-01

A qualitative and quantitative comparison of registration CT-CT, CT-MR and CT-SPECT performed by the different software and algorithms studies is presented. Only two studied software were full DICOM RT compatible while accepting DICOM images in any layout. Quantitative results of fiducial displacement errors were calculated for all software and available registration methods. The presented methodology demonstrated being effective for assessing the quality of studied image registration tools in the radiotherapy planning context, provided the images are free of significant geometric deformation. When implementing this methodology in real patients, the use of immobilization devices, such as thermoplastic masks, is recommended for enhanced quality of image registration. (Author)

Challenges for the registration of vaccines in emerging countries: Differences in dossier requirements, application and evaluation processes.

Science.gov (United States)

Dellepiane, Nora; Pagliusi, Sonia

2018-06-07

The divergence of regulatory requirements and processes in developing and emerging countries contributes to hamper vaccines' registration, and therefore delay access to high-quality, safe and efficacious vaccines for their respective populations. This report focuses on providing insights on the heterogeneity of registration requirements in terms of numbering structure and overall content of dossiers for marketing authorisation applications for vaccines in different areas of the world. While it also illustrates the divergence of regulatory processes in general, as well as the need to avoid redundant reviews, it does not claim to provide a comprehensive view of all processes nor existing facilitating mechanisms, nor is it intended to touch upon the differences in assessments made by different regulatory authorities. This report describes the work analysed by regulatory experts from vaccine manufacturing companies during a meeting held in Geneva in May 2017, in identifying and quantifying differences in the requirements for vaccine registration in three aspects for comparison: the dossier numbering structure and contents, the application forms, and the evaluation procedures, in different countries and regions. The Module 1 of the Common Technical Document (CTD) of 10 countries were compared. Modules 2-5 of the CTDs of two regions and three countries were compared to the CTD of the US FDA. The application forms of eight countries were compared and the registration procedures of 134 importing countries were compared as well. The analysis indicates a high degree of divergence in numbering structure and content requirements. Possible interventions that would lead to significant improvements in registration efficiency include alignment in CTD numbering structure, a standardised model-application form, and better convergence of evaluation procedures. Copyright © 2018.

Performance Evaluation and Optimal Management of Distance-Based Registration Using a Semi-Markov Process

Directory of Open Access Journals (Sweden)

Jae Joon Suh

2017-01-01

Full Text Available We consider the distance-based registration (DBR which is a kind of dynamic location registration scheme in a mobile communication network. In the DBR, the location of a mobile station (MS is updated when it enters a base station more than or equal to a specified distance away from the base station where the location registration for the MS was done last. In this study, we first investigate the existing performance-evaluation methods on the DBR with implicit registration (DBIR presented to improve the performance of the DBR and point out some problems of the evaluation methods. We propose a new performance-evaluation method for the DBIR scheme using a semi-Markov process (SMP which can resolve the controversial issues of the existing methods. The numerical results obtained with the proposed SMP model are compared with those from previous models. It is shown that the SMP model should be considered to get an accurate performance of the DBIR scheme.

Study of different registration methods for on-line kilovoltage cone-beam CT guided lung cancer radiation

International Nuclear Information System (INIS)

Wang Yanyang; Fu Xiaolong; Xia Bing; Wu Zhengqin; Fan Min; Yang Huanjun; Xu Zhiyong; Jiang Guoliang

2009-01-01

Objective: To select the optimal registration method for on-line kilovoltage cone-beam CT (KVCBCT) guided lung cancer radiation and evaluate the reproducibility of the selected method. Methods: Sixteen patients with non-small cell lung cancer were enrolled into this study. A total of 96 pretreatment KVCBCT images from the 16 patients were available for the analysis. Image registration methods were bone-based automatic registration, gray-based automatic registration, manual registration and semi-automatic registration. All registrations were accomplished by one physician. Another physician blindly evaluated the results of each registration, then selected the optimal registration method and evaluated its reproducibility. Results: The average score of the bone-based automatic registration, gray-based automatic registration, manual registration and semi-automatic registration methods was 2.4, 2.7, 3.0 and 3.7, respectively. The score of the four different groups had statistics significant difference (F=42.20, P<0.001). Using the semi-automatic registration method, the probability of the difference between two registration results more than 3 mm in the left-right, superior-inferior, and anterior-posterior directions was 0, 3% and 6% by the same physician, 0, 14% and 0 by different physicians, and 8%, 14% and 8% by physician and radiation therapist. Conclusions: Semi-automatic registration method, possessing the highest score and accepted reproducibility, is appropriate for KVCBCT guided lung cancer radiation. (authors)

Automatic 3D MR image registration and its evaluation for precise monitoring of knee joint disease

International Nuclear Information System (INIS)

Cheng Yuanzhi; Jin Quan; Guo Changyong; Ding Xiaohua; Tanaka, Hisashi; Tamura, Shinichi

2011-01-01

We describe a technique for the registration of three dimensional (3D) knee femur surface points from MR image data sets; it is a technique that can track local cartilage thickness changes over time. In the first coarse registration step, we use the direction vectors of the volume given by the cloud of points of the MR image to correct for different knee joint positions and orientations in the MR scanner. In the second fine registration step, we propose a global search algorithm that simultaneously determines the optimal transformation parameters and point correspondences through searching a six dimensional space of Euclidean motion vectors (translation and rotation). The present algorithm is grounded on a mathematical theory- Lipschitz optimization. Compared with the other three registration approaches (iterative closest point (ICP), EM-ICP, and genetic algorithms), the proposed method achieved the highest registration accuracy on both animal and clinical data. (author)

ER-1A-DEL-92 regulation. Procedure for evaluation and registration of medical equipment

International Nuclear Information System (INIS)

2015-01-01

The objectives of this regulation is to provide additional guidance on the method of evaluation and registration of a medical team, so it is used by manufacturers, health institutions, testing centers and other institutions related to the topic. The provisions of this regulation apply to domestically produced medical equipment in relation to the necessary assessment for registration purposes of a medical team. However, the evaluation process may require evaluations and tests not explicitly included in this regulation, so that at each stage of the process the Center for State Control of Medical Equipment (Center) set the requirements for each computer or device class in particular.

Anisotropic multi-scale fluid registration: evaluation in magnetic resonance breast imaging

International Nuclear Information System (INIS)

Crum, W R; Tanner, C; Hawkes, D J

2005-01-01

Registration using models of compressible viscous fluids has not found the general application of some other techniques (e.g., free-form-deformation (FFD)) despite its ability to model large diffeomorphic deformations. We report on a multi-resolution fluid registration algorithm which improves on previous work by (a) directly solving the Navier-Stokes equation at the resolution of the images (b) accommodating image sampling anisotropy using semi-coarsening and implicit smoothing in a full multi-grid (FMG) solver and (c) exploiting the inherent multi-resolution nature of FMG to implement a multi-scale approach. Evaluation is on five magnetic resonance (MR) breast images subject to six biomechanical deformation fields over 11 multi-resolution schemes. Quantitative assessment is by tissue overlaps and target registration errors and by registering using the known correspondences rather than image features to validate the fluid model. Context is given by comparison with a validated FFD algorithm and by application to images of volunteers subjected to large applied deformation. The results show that fluid registration of 3D breast MR images to sub-voxel accuracy is possible in minutes on a 1.6 GHz Linux-based Athlon processor with coarse solutions obtainable in a few tens of seconds. Accuracy and computation time are comparable to FFD techniques validated for this application

Accuracy evaluation of initialization-free registration for intraoperative 3D-navigation

International Nuclear Information System (INIS)

Diakov, Georgi; Freysinger, Wolfgang

2007-01-01

Purpose An initialization-free approach for perioperative registration in functional endoscopic sinus surgery (FESS) is sought. The quality of surgical navigation relies on registration accuracy of preoperative images to the patient. Although landmark-based registration is fast, it is prone to human operator errors. This study evaluates the accuracy of two well-known methods for segmentation of the occipital bone from CT-images for use in surgical 3D-navigation. Method The occipital bone was segmented for registration without pre-defined correspondences, with the iterative closest point algorithm (ICP). The thresholding plus marching cubes segmentation (TMCS), and the deformable model segmentation (DMS) were compared quantitatively by overlaying the areas of the segmentations in cross-sectional slices, and visually by displaying the pointwise distances between the segmentations in a three-dimensional distance map relative to an expert manual segmentation, taken as a ''ground truth''. Results Excellent correspondence between the two methods was achieved; the results showed, however, that the TMCS is closer to the ''ground truth''. This is due to the sub-voxel accuracy of the marching cubes algorithm by definition, and the sensitivity of the DMS method to the choice of parameters. The DMS approach, as a gradient-based method, is insensitive to the thresholding initialization. For noisy images and soft tissue delineation a gradient-based method, like the deformable model, performs better. Both methods correspond within minute differences less than 4%. Conclusion These results will allow further minimization of human interaction in the planning phase for intraoperative 3D-navigation, by allowing to automatically create surface patches for registration purposes, ultimately allowing to build an initialization-free, fully automatic registration procedure for navigated Ear-, Nose-, Throat- (ENT) surgery. (orig.)

European regulation model for herbal medicine: The assessment of the EU monograph and the safety and efficacy evaluation in marketing authorization or registration in Member States.

Science.gov (United States)

Qu, Liping; Zou, Wenjun; Wang, YiTao; Wang, Mei

2018-03-15

The European Union (EU) has created a regulatory framework for herbal medicinal products (HMPs) since the enforcement of Directive 2004/24/EC. Substantial achievements have been made, with 1719 traditional use marketing registrations (TURs) and 859 well-established use marketing authorizations (WEU-MAs) for HMPs granted by the end of 2016. Apparently, the European regulation model has worked out well and in that the essential feature is the use of EU herbal monographs into those granted WEU-MAs and TURs. A systematic analysis of the European regulation model for HMPs and the EU herbal monograph's part of this model are undertaken to assist understanding of the EU legislation particularly for interested parties those from outside EU area, and afterwards, to help in decision-making in the HMPs registration in European market for pharmaceutical companies, as well as in the establishment of legislation in countries with strong traditional use of herbal remedies. A search of PubMed, ScienceDirect, the European Medicines Agency website and the Heads of Medicines Agencies website was conducted (up to December 2017), and the available information on regulation of HMPs in the EU was collected. The evaluation of applications by National Competent Authorities (NCAs) at a national level together with the assessment of EU monographs by the Committee on Herbal Medicinal Products (HMPC) at the European level constitute the European regulation framework for HMPs. As the scientific opinion about the safety and efficacy of HMPs from HMPC, the EU herbal monographs have been given a constitutional-based meaning to the TURs and WEU-MAs of HMPs and play a supportive function in the marketing procedure in Member States. The European framework has provided a powerful regulation model for harmonization of scientific assessment and facilitation of product marketing. For the pharmaceutical industries particularly those outside the EU, optimal use of the EU herbal monograph in their marketing

Usefulness of the classification technique of cerebral artery for 2D/3D registration

International Nuclear Information System (INIS)

Takemura, Akihiro; Suzuki, Masayuki; Kikuchi, Yuzo; Okumura, Yusuke; Harauchi, Hajime

2007-01-01

Several papers have proposed 2D/3D registration methods of the cerebral artery using magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). Since differences between vessels in a DSA image and MRA volume data cause registration failure, we previously proposed a method to extract vessels from MRA volume data using a technique based on classification of the cerebral artery. In this paper, we evaluated the usefulness of this classification technique by evaluating the reliability of this 2D/3D registration method. This classification method divides the cerebral artery in MRA volume data into 12 segments. According to the results of the classification, structures corresponding to vessels on a DSA image can then be extracted. We applied the 2D/3D registration with/without classification to 16 pairs of MRA volume data and DSA images obtained from six patients. The registration results were scored into four levels (Excellent, Good, Fair and Poor). The rates of successful registration (>fair) were 37.5% for registration without classification and 81.3% for that with classification. These findings suggested that there was a low percentage of incorrectly extracted voxels and we could facilitate reliable registration. Thus, the classification technique was shown to be useful for feature-based 2D/3D registration. (author)

Deformable image registration for image guided prostate radiotherapy

International Nuclear Information System (INIS)

Cassetta, Roberto; Riboldi, Marco; Baroni, Guido; Leandro, Kleber; Novaes, Paulo Eduardo; Goncalves, Vinicius; Sakuraba, Roberto; Fattori, Giovanni

2016-01-01

In this study, we present a CT to CBCT deformable registration method based on the ITK library. An algorithm was developed in order to explore the soft tissue information of the CT-CBCT images to perform deformable image registration (DIR), making efforts to overcome the poor signal-to-noise ratio and HU calibration issues that limits CBCT use for treatment planning purposes. Warped CT images and contours were generated and their impact in adaptive radiotherapy was evaluated by DVH analysis for photon and proton treatments. Considerable discrepancies, related to the treatment planning dose distribution, might be found due to changes in patient’s anatomy. (author)

Multimodal Registration of gated cardiac PET, CT and MR sequences

International Nuclear Information System (INIS)

Baty, X.

2007-07-01

The research described in this manuscript deals with the multimodal registration of cardiac images from Magnetic Resonance Imaging (MRI), Position Emission Tomography (PET) and Computerized Tomography (CT). All these modalities are gated to the Electrocardiogram (ECG) and provide information to evaluate cardiac function, and to diagnose and to follow-up cardiovascular pathologies. PET imaging allows the evaluation of ventricular function and MRI is a gold standard for the study of the left ventricular function. The goal of our registration process is to merge functional (from PET) and anatomical images (from CT and MRI). Our process is adapted to the modalities used and is divided in two steps: (i) a global rigid 3-dimensional model-based ICP (Iterative Closest Point) registration between CT and MR data and (ii) an iconic 2-dimensional registration based on Free Form Deformations and Mutual Information. This last step presents an original contribution by using a composite image of CT (which presents epicardic contours) and PET (where endocardic contours are partially visible) data to make mutual information more accurate in representing the similarity with the MR data. To speed up the whole process, we also present a transformation initialization scheme using displacement field obtained form MR data only. The obtained results have been evaluated by experts. (author)

Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images

International Nuclear Information System (INIS)

Kanai, Takayuki; Kadoya, Noriyuki; Ito, Kengo

2014-01-01

Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy. (author)

Analysis of the utilization of existing test data for phase-in substance registration under the Act on the Registration and Evaluation, etc. of Chemical Substances.

Science.gov (United States)

Choi, Bong-In; Kwak, Yeong-Don; Jung, Yu-Mi; Ryu, Byung-Taek; Kim, Chang Gyun

2015-01-01

Approximately 2000 phase-in substances are subject to registration according to the Act on the Registration and Evaluation, etc. of Chemical Substances (KREACH), and the expected testing cost is 2.06 trillion Korean won assuming all the test data required for registration are acquired. The extent to which these enormous test costs can be reduced depends on the availability of existing data that can be used to meet the requirements of the K-REACH we examined the current availability of test data that can be used for chemical substance registration. We analyzed the possibility of utilizing the existing test data obtained from 16 reference databases for 369 of 518 kinds of phase-in substances subject to registration that were reported in last October 2014. The physical and chemical properties were available for 57.1% of substances, whereas data regarding human hazards and environmental hazards were available at considerably lower rates, 8.5% and 11.8%, respectively. Physical and chemical properties were available for a fairly high proportion, whereas human hazards and environmental hazards were reported for considerably fewer substances.

EAS Equipment Authorization Grantee Registrations

Data.gov (United States)

Federal Communications Commission — EAS (Equipment Authorization System). Radio Frequency (RF) devices are required to be properly authorized under 47 CFR Part 2 prior to being marketed or imported...

Novel image registration quality evaluator (RQE) with an implementation for automated patient positioning in cranial radiation therapy

International Nuclear Information System (INIS)

Wu Jian; Samant, Sanjiv S.

2007-01-01

In external beam radiation therapy, digitally reconstructed radiographs (DRRs) and portal images are used to verify patient setup based either on a visual comparison or, less frequently, with automated registration algorithms. A registration algorithm can be trapped in local optima due to irregularity of patient anatomy, image noise and artifacts, and/ or out-of-plane shifts, resulting in an incorrect solution. Thus, human observation, which is subjective, is still required to check the registration result. We propose to use a novel image registration quality evaluator (RQE) to automatically identify misregistrations as part of an algorithm-based decision-making process for verification of patient positioning. A RQE, based on an adaptive pattern classifier, is generated from a pair of reference and target images to determine the acceptability of a registration solution given an optimization process. Here we applied our RQE to patient positioning for cranial radiation therapy. We constructed two RQEs--one for the evaluation of intramodal registrations (i.e., portal-portal); the other for intermodal registrations (i.e., portal-DRR). Mutual information, because of its high discriminatory ability compared with other measures (i.e., correlation coefficient and partitioned intensity uniformity), was chosen as the test function for both RQEs. We adopted 1 mm translation and 1 deg. rotation as the maximal acceptable registration errors, reflecting desirable clinical setup tolerances for cranial radiation therapy. Receiver operating characteristic analysis was used to evaluate the performance of the RQE, including computations of sensitivity and specificity. The RQEs showed very good performance for both intramodal and intermodal registrations using simulated and phantom data. The sensitivity and the specificity were 0.973 and 0.936, respectively, for the intramodal RQE using phantom data. Whereas the sensitivity and the specificity were 0.961 and 0.758, respectively, for

Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images.

Science.gov (United States)

Kanai, Takayuki; Kadoya, Noriyuki; Ito, Kengo; Onozato, Yusuke; Cho, Sang Yong; Kishi, Kazuma; Dobashi, Suguru; Umezawa, Rei; Matsushita, Haruo; Takeda, Ken; Jingu, Keiichi

2014-11-01

Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Evaluation of whole-body MR to CT deformable image registration

NARCIS (Netherlands)

Akbarzadeh, A.; Gutierrez, D.; Baskin, A.; Ay, M. R.; Ahmadian, A.; Alam, N. Riahi; Loevblad, K. O.; Zaidi, H.

2013-01-01

Multimodality image registration plays a crucial role in various clinical and research applications. The aim of this study is to present an optimized MR to CT whole-body deformable image registration algorithm and its validation using clinical studies. A 3D intermodality registration technique based

Automated registration of diagnostic to prediagnostic x-ray mammograms: Evaluation and comparison to radiologists' accuracy

International Nuclear Information System (INIS)

Pinto Pereira, Snehal M.; Hipwell, John H.; McCormack, Valerie A.; Tanner, Christine; Moss, Sue M.; Wilkinson, Louise S.; Khoo, Lisanne A. L.; Pagliari, Catriona; Skippage, Pippa L.; Kliger, Carole J.; Hawkes, David J.; Santos Silva, Isabel M. dos

2010-01-01

Purpose: To compare and evaluate intensity-based registration methods for computation of serial x-ray mammogram correspondence. Methods: X-ray mammograms were simulated from MRIs of 20 women using finite element methods for modeling breast compressions and employing a MRI/x-ray appearance change model. The parameter configurations of three registration methods, affine, fluid, and free-form deformation (FFD), were optimized for registering x-ray mammograms on these simulated images. Five mammography film readers independently identified landmarks (tumor, nipple, and usually two other normal features) on pairs of diagnostic and corresponding prediagnostic digitized images from 52 breast cancer cases. Landmarks were independently reidentified by each reader. Target registration errors were calculated to compare the three registration methods using the reader landmarks as a gold standard. Data were analyzed using multilevel methods. Results: Between-reader variability varied with landmark (p<0.01) and screen (p=0.03), with between-reader mean distance (mm) in point location on the diagnostic/prediagnostic images of 2.50 (95% CI 1.95, 3.15)/2.84 (2.24, 3.55) for nipples and 4.26 (3.43, 5.24)/4.76 (3.85, 5.84) for tumors. Registration accuracy was sensitive to the type of landmark and the amount of breast density. For dense breasts (≥40%), the affine and fluid methods outperformed FFD. For breasts with lower density, the affine registration surpassed both fluid and FFD. Mean accuracy (mm) of the affine registration varied between 3.16 (95% CI 2.56, 3.90) for nipple points in breasts with density 20%-39% and 5.73 (4.80, 6.84) for tumor points in breasts with density <20%. Conclusions: Affine registration accuracy was comparable to that between independent film readers. More advanced two-dimensional nonrigid registration algorithms were incapable of increasing the accuracy of image alignment when compared to affine registration.

Standard review plan for applications for sealed source and device evaluations and registrations

International Nuclear Information System (INIS)

1996-11-01

The purpose of this document is to provide the reviewer of a request for a sealed source or device safety evaluation with the information and materials necessary to make a determination that the product is acceptable for licensing purposes. It provides the reviewer with a listing of the applicable regulations and industry standards, policies affecting evaluation and registration, certain administrative procedures to be followed, and information on how to perform the evaluation and write the registration certificate. Standard review plans are prepared for the guidance of the Office of Nuclear Material Safety and Safeguards staff responsible for the review of a sealed source or device application. This document is made available to the public as part of the Commission's policy to inform the nuclear industry and the general public of regulatory procedures and policies. Standard review plans are not substitutes for regulatory guides or the Commission's regulations and compliance with them is not required

Standard review plan for applications for sealed source and device evaluations and registrations

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The purpose of this document is to provide the reviewer of a request for a sealed source or device safety evaluation with the information and materials necessary to make a determination that the product is acceptable for licensing purposes. It provides the reviewer with a listing of the applicable regulations and industry standards, policies affecting evaluation and registration, certain administrative procedures to be followed, and information on how to perform the evaluation and write the registration certificate. Standard review plans are prepared for the guidance of the Office of Nuclear Material Safety and Safeguards staff responsible for the review of a sealed source or device application. This document is made available to the public as part of the Commission`s policy to inform the nuclear industry and the general public of regulatory procedures and policies. Standard review plans are not substitutes for regulatory guides or the Commission`s regulations and compliance with them is not required.

Frameless image registration of X-ray CT and SPECT by volume matching

International Nuclear Information System (INIS)

Tanaka, Yuko; Kihara, Tomohiko; Yui, Nobuharu; Kinoshita, Fujimi; Kamimura, Yoshitsugu; Yamada, Yoshifumi.

1998-01-01

Image registration of functional (SPECT) and morphological (X-ray CT/MRI) images is studied in order to improve the accuracy and the quantity of the image diagnosis. We have developed a new frameless registration method of X-ray CT and SPECT image using transmission CT image acquired for absorption correction of SPECT images. This is the automated registration method and calculates the transformation matrix between the two coordinate systems of image data by the optimization method. This registration method is based on the similar physical property of X-ray CT and transmission CT image. The three-dimensional overlap of the bone region is used for image matching. We verified by a phantom test that it can provide a good result of within two millimeters error. We also evaluated visually the accuracy of the registration method by the application study of SPECT, X-ray CT, and transmission CT head images. This method can be carried out accurately without any frames. We expect this registration method becomes an efficient tool to improve image diagnosis and medical treatment. (author)

Automated image registration for FDOPA PET studies

International Nuclear Information System (INIS)

Kang-Ping Lin; Sung-Cheng Huang, Dan-Chu Yu; Melega, W.; Barrio, J.R.; Phelps, M.E.

1996-01-01

In this study, various image registration methods are investigated for their suitability for registration of L-6-[18F]-fluoro-DOPA (FDOPA) PET images. Five different optimization criteria including sum of absolute difference (SAD), mean square difference (MSD), cross-correlation coefficient (CC), standard deviation of pixel ratio (SDPR), and stochastic sign change (SSC) were implemented and Powell's algorithm was used to optimize the criteria. The optimization criteria were calculated either unidirectionally (i.e. only evaluating the criteria for comparing the resliced image 1 with the original image 2) or bidirectionally (i.e. averaging the criteria for comparing the resliced image 1 with the original image 2 and those for the sliced image 2 with the original image 1). Monkey FDOPA images taken at various known orientations were used to evaluate the accuracy of different methods. A set of human FDOPA dynamic images was used to investigate the ability of the methods for correcting subject movement. It was found that a large improvement in performance resulted when bidirectional rather than unidirectional criteria were used. Overall, the SAD, MSD and SDPR methods were found to be comparable in performance and were suitable for registering FDOPA images. The MSD method gave more adequate results for frame-to-frame image registration for correcting subject movement during a dynamic FDOPA study. The utility of the registration method is further demonstrated by registering FDOPA images in monkeys before and after amphetamine injection to reveal more clearly the changes in spatial distribution of FDOPA due to the drug intervention. (author)

Preliminary study of lateral cerebral angiography with reverse rotation in the digital image registration and subtraction

International Nuclear Information System (INIS)

Shen Zhenglin; Liu Dongyang; Shen Zhenghai; Li Shuping; Zhang Ziyan; Wu Yongjuan; Liu Peijun

2012-01-01

Objective: Investigate the value and feasibility of image registration with reverse rotation in lateral cerebral DSA. Methods: (1) Experimental study: the target images were subtracted directly, and subtracted again after reverse rotation. Software of registration and subtraction with reverse rotation edited by the author utilizing Visual Basic. The function of the automatic angle detection by the software were evaluated to see whether it detected the angle of line. The subtraction function of DSA by the software was evaluated. (2) Clinical retrospective study: the untreated mask and target images of 15 patients with motion along vertical axis during lateral cerebral DSA were uploaded to the software. The target images were processed with and without the software to get two sets of images. (3) Evaluation: four experienced radiologists read and compared the two sets of the images,and graded their findings. Results: (1) The automatic detection by the software suggested that the target images should be rotated counterclockwise 1.3°. The subtraction result of the software was satisfactory. (2) In the 15 sets of images, there were only three sets of images deemed optimal after traditional subtraction. After reverse rotation, artifacts were significantly reduced and the image sharper. There were ten cases with significant artifacts after traditional subtraction, and those images were sharper and showed more peripheral vessels after reverse rotation. The traditional subtraction images of two sets could not be interpreted,the reverse rotation registration images reached the diagnostic quality. (3) Subjective evaluation: there were more information and less noise and distortion in the registration images with reverse rotation than in the traditional subtraction. But the image resolution decreased slightly after reverse rotation registration. Conclusion: The registration of digital angiography with reverse rotation can improve the image quality in lateral cerebral DSA

A Bayesian nonrigid registration method to enhance intraoperative target definition in image-guided prostate procedures through uncertainty characterization

International Nuclear Information System (INIS)

Pursley, Jennifer; Risholm, Petter; Fedorov, Andriy; Tuncali, Kemal; Fennessy, Fiona M.; Wells, William M. III; Tempany, Clare M.; Cormack, Robert A.

2012-01-01

Purpose: This study introduces a probabilistic nonrigid registration method for use in image-guided prostate brachytherapy. Intraoperative imaging for prostate procedures, usually transrectal ultrasound (TRUS), is typically inferior to diagnostic-quality imaging of the pelvis such as endorectal magnetic resonance imaging (MRI). MR images contain superior detail of the prostate boundaries and provide substructure features not otherwise visible. Previous efforts to register diagnostic prostate images with the intraoperative coordinate system have been deterministic and did not offer a measure of the registration uncertainty. The authors developed a Bayesian registration method to estimate the posterior distribution on deformations and provide a case-specific measure of the associated registration uncertainty. Methods: The authors adapted a biomechanical-based probabilistic nonrigid method to register diagnostic to intraoperative images by aligning a physician's segmentations of the prostate in the two images. The posterior distribution was characterized with a Markov Chain Monte Carlo method; the maximum a posteriori deformation and the associated uncertainty were estimated from the collection of deformation samples drawn from the posterior distribution. The authors validated the registration method using a dataset created from ten patients with MRI-guided prostate biopsies who had both diagnostic and intraprocedural 3 Tesla MRI scans. The accuracy and precision of the estimated posterior distribution on deformations were evaluated from two predictive distance distributions: between the deformed central zone-peripheral zone (CZ-PZ) interface and the physician-labeled interface, and based on physician-defined landmarks. Geometric margins on the registration of the prostate's peripheral zone were determined from the posterior predictive distance to the CZ-PZ interface separately for the base, mid-gland, and apical regions of the prostate. Results: The authors observed

TU-B-19A-01: Image Registration II: TG132-Quality Assurance for Image Registration

International Nuclear Information System (INIS)

Brock, K; Mutic, S

2014-01-01

AAPM Task Group 132 was charged with a review of the current approaches and solutions for image registration in radiotherapy and to provide recommendations for quality assurance and quality control of these clinical processes. As the results of image registration are always used as the input of another process for planning or delivery, it is important for the user to understand and document the uncertainty associate with the algorithm in general and the Result of a specific registration. The recommendations of this task group, which at the time of abstract submission are currently being reviewed by the AAPM, include the following components. The user should understand the basic image registration techniques and methods of visualizing image fusion. The disclosure of basic components of the image registration by commercial vendors is critical in this respect. The physicists should perform end-to-end tests of imaging, registration, and planning/treatment systems if image registration is performed on a stand-alone system. A comprehensive commissioning process should be performed and documented by the physicist prior to clinical use of the system. As documentation is important to the safe implementation of this process, a request and report system should be integrated into the clinical workflow. Finally, a patient specific QA practice should be established for efficient evaluation of image registration results. The implementation of these recommendations will be described and illustrated during this educational session. Learning Objectives: Highlight the importance of understanding the image registration techniques used in their clinic. Describe the end-to-end tests needed for stand-alone registration systems. Illustrate a comprehensive commissioning program using both phantom data and clinical images. Describe a request and report system to ensure communication and documentation. Demonstrate an clinically-efficient patient QA practice for efficient evaluation of image

Evaluation of linear registration algorithms for brain SPECT and the errors due to hypoperfusion lesions

International Nuclear Information System (INIS)

Radau, Perry E.; Slomka, Piotr J.; Julin, Per; Svensson, Leif; Wahlund, Lars-Olof

2001-01-01

The semiquantitative analysis of perfusion single-photon emission computed tomography (SPECT) images requires a reproducible, objective method. Automated spatial standardization (registration) of images is a prerequisite to this goal. A source of registration error is the presence of hypoperfusion defects, which was evaluated in this study with simulated lesions. The brain perfusion images measured by 99m Tc-HMPAO SPECT from 21 patients with probable Alzheimer's disease and 35 control subjects were retrospectively analyzed. An automatic segmentation method was developed to remove external activity. Three registration methods, robust least squares, normalized mutual information (NMI), and count difference were implemented and the effects of simulated defects were compared. The tested registration methods required segmentation of the cerebrum from external activity, and the automatic and manual methods differed by a three-dimensional displacement of 1.4±1.1 mm. NMI registration proved to be least adversely effected by simulated defects with 3 mm average displacement caused by severe defects. The error in quantifying the patient-template parietal ratio due to misregistration was 2.0% for large defects (70% hypoperfusion) and 0.5% for smaller defects (85% hypoperfusion)

Registration factors that limit international mobility of people holding physiotherapy qualifications: A systematic review.

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Foo, Jonathan S; Storr, Michael; Maloney, Stephen

2016-06-01

There is no enforced international standardisation of the physiotherapy profession. Thus, registration is used in many countries to maintain standards of care and to protect the public. However, registration may also limit international workforce mobility. What is known about the professional registration factors that may limit the international mobility of people holding physiotherapy qualifications? Systematic review using an electronic database search and hand searching of the World Confederation for Physical Therapy and International Network of Physiotherapy Regulatory Authorities websites. Analysis was conducted using thematic analysis. 10 articles and eight websites were included from the search strategy. Data is representative of high-income English speaking countries. Four themes emerged regarding limitations to professional mobility: practice context, qualification recognition, verification of fitness to practice, and incidental limitations arising from the registration process. Professional mobility is limited by differences in physiotherapy education programmes, resulting in varying standards of competency. Thus, it is often necessary to verify clinical competencies through assessments, as well as determining professional attributes and ability to apply competencies in a different practice context, as part of the registration process. There has been little evaluation of registration practices, and at present, there is a need to re-evaluate current registration processes to ensure they are efficient and effective, thereby enhancing workforce mobility. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

3D-2D registration in endovascular image-guided surgery: evaluation of state-of-the-art methods on cerebral angiograms.

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Mitrović, Uroš; Likar, Boštjan; Pernuš, Franjo; Špiclin, Žiga

2018-02-01

Image guidance for minimally invasive surgery is based on spatial co-registration and fusion of 3D pre-interventional images and treatment plans with the 2D live intra-interventional images. The spatial co-registration or 3D-2D registration is the key enabling technology; however, the performance of state-of-the-art automated methods is rather unclear as they have not been assessed under the same test conditions. Herein we perform a quantitative and comparative evaluation of ten state-of-the-art methods for 3D-2D registration on a public dataset of clinical angiograms. Image database consisted of 3D and 2D angiograms of 25 patients undergoing treatment for cerebral aneurysms or arteriovenous malformations. On each of the datasets, highly accurate "gold-standard" registrations of 3D and 2D images were established based on patient-attached fiducial markers. The database was used to rigorously evaluate ten state-of-the-art 3D-2D registration methods, namely two intensity-, two gradient-, three feature-based and three hybrid methods, both for registration of 3D pre-interventional image to monoplane or biplane 2D images. Intensity-based methods were most accurate in all tests (0.3 mm). One of the hybrid methods was most robust with 98.75% of successful registrations (SR) and capture range of 18 mm for registrations of 3D to biplane 2D angiograms. In general, registration accuracy was similar whether registration of 3D image was performed onto mono- or biplanar 2D images; however, the SR was substantially lower in case of 3D to monoplane 2D registration. Two feature-based and two hybrid methods had clinically feasible execution times in the order of a second. Performance of methods seems to fall below expectations in terms of robustness in case of registration of 3D to monoplane 2D images, while translation into clinical image guidance systems seems readily feasible for methods that perform registration of the 3D pre-interventional image onto biplanar intra

Automated registration of diagnostic to prediagnostic x-ray mammograms: Evaluation and comparison to radiologists' accuracy

Energy Technology Data Exchange (ETDEWEB)

Pinto Pereira, Snehal M.; Hipwell, John H.; McCormack, Valerie A.; Tanner, Christine; Moss, Sue M.; Wilkinson, Louise S.; Khoo, Lisanne A. L.; Pagliari, Catriona; Skippage, Pippa L.; Kliger, Carole J.; Hawkes, David J.; Santos Silva, Isabel M. dos [Cancer Research UK Epidemiology and Genetics Group, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT (United Kingdom); Centre for Medical Image Computing, University College London, London WC1E 6BT (United Kingdom); Lifestyle and Cancer Group, International Agency for Research on Cancer, 150 cours Albert Thomas, Lyon 69008 (France); Centre for Medical Image Computing, University College London, London WC1E 6BT (United Kingdom); Cancer Screening Evaluation Unit, Institute of Cancer Research, Surrey SM2 5NG (United Kingdom); St. George' s Healthcare NHS Trust and South West London Breast Screening Service, London SW17 0QT (United Kingdom); Centre for Medical Image Computing, University College London, London WC1E 6BT (United Kingdom); Cancer Research UK Epidemiology and Genetics Group, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT (United Kingdom)

2010-09-15

Purpose: To compare and evaluate intensity-based registration methods for computation of serial x-ray mammogram correspondence. Methods: X-ray mammograms were simulated from MRIs of 20 women using finite element methods for modeling breast compressions and employing a MRI/x-ray appearance change model. The parameter configurations of three registration methods, affine, fluid, and free-form deformation (FFD), were optimized for registering x-ray mammograms on these simulated images. Five mammography film readers independently identified landmarks (tumor, nipple, and usually two other normal features) on pairs of diagnostic and corresponding prediagnostic digitized images from 52 breast cancer cases. Landmarks were independently reidentified by each reader. Target registration errors were calculated to compare the three registration methods using the reader landmarks as a gold standard. Data were analyzed using multilevel methods. Results: Between-reader variability varied with landmark (p<0.01) and screen (p=0.03), with between-reader mean distance (mm) in point location on the diagnostic/prediagnostic images of 2.50 (95% CI 1.95, 3.15)/2.84 (2.24, 3.55) for nipples and 4.26 (3.43, 5.24)/4.76 (3.85, 5.84) for tumors. Registration accuracy was sensitive to the type of landmark and the amount of breast density. For dense breasts ({>=}40%), the affine and fluid methods outperformed FFD. For breasts with lower density, the affine registration surpassed both fluid and FFD. Mean accuracy (mm) of the affine registration varied between 3.16 (95% CI 2.56, 3.90) for nipple points in breasts with density 20%-39% and 5.73 (4.80, 6.84) for tumor points in breasts with density <20%. Conclusions: Affine registration accuracy was comparable to that between independent film readers. More advanced two-dimensional nonrigid registration algorithms were incapable of increasing the accuracy of image alignment when compared to affine registration.

A high-accuracy image registration algorithm using phase-only correlation for dental radiographs

International Nuclear Information System (INIS)

Ito, Koichi; Nikaido, Akira; Aoki, Takafumi; Kosuge, Eiko; Kawamata, Ryota; Kashima, Isamu

2008-01-01

Dental radiographs have been used for the accurate assessment and treatment of dental diseases. The nonlinear deformation between two dental radiographs may be observed, even if they are taken from the same oral regions of the subject. For an accurate diagnosis, the complete geometric registration between radiographs is required. This paper presents an efficient dental radiograph registration algorithm using Phase-Only Correlation (POC) function. The use of phase components in 2D (two-dimensional) discrete Fourier transforms of dental radiograph images makes possible to achieve highly robust image registration and recognition. Experimental evaluation using a dental radiograph database indicates that the proposed algorithm exhibits efficient recognition performance even for distorted radiographs. (author)

Assessment of rigid multi-modality image registration consistency using the multiple sub-volume registration (MSR) method

International Nuclear Information System (INIS)

Ceylan, C; Heide, U A van der; Bol, G H; Lagendijk, J J W; Kotte, A N T J

2005-01-01

Registration of different imaging modalities such as CT, MRI, functional MRI (fMRI), positron (PET) and single photon (SPECT) emission tomography is used in many clinical applications. Determining the quality of any automatic registration procedure has been a challenging part because no gold standard is available to evaluate the registration. In this note we present a method, called the 'multiple sub-volume registration' (MSR) method, for assessing the consistency of a rigid registration. This is done by registering sub-images of one data set on the other data set, performing a crude non-rigid registration. By analysing the deviations (local deformations) of the sub-volume registrations from the full registration we get a measure of the consistency of the rigid registration. Registration of 15 data sets which include CT, MR and PET images for brain, head and neck, cervix, prostate and lung was performed utilizing a rigid body registration with normalized mutual information as the similarity measure. The resulting registrations were classified as good or bad by visual inspection. The resulting registrations were also classified using our MSR method. The results of our MSR method agree with the classification obtained from visual inspection for all cases (p < 0.02 based on ANOVA of the good and bad groups). The proposed method is independent of the registration algorithm and similarity measure. It can be used for multi-modality image data sets and different anatomic sites of the patient. (note)

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation

Directory of Open Access Journals (Sweden)

Niranjan Joshi

2013-01-01

Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Markerless laser registration in image-guided oral and maxillofacial surgery.

Science.gov (United States)

Marmulla, Rüdiger; Lüth, Tim; Mühling, Joachim; Hassfeld, Stefan

2004-07-01

The use of registration markers in computer-assisted surgery is combined with high logistic costs and efforts. Markerless patient registration using laser scan surface registration techniques is a new challenging method. The present study was performed to evaluate the clinical accuracy in finding defined target points within the surgical site after markerless patient registration in image-guided oral and maxillofacial surgery. Twenty consecutive patients with different cranial diseases were scheduled for computer-assisted surgery. Data set alignment between the surgical site and the computed tomography (CT) data set was performed by markerless laser scan surface registration of the patient's face. Intraoral rigidly attached registration markers were used as target points, which had to be detected by an infrared pointer. The Surgical Segment Navigator SSN++ has been used for all procedures. SSN++ is an investigative product based on the SSN system that had previously been developed by the presenting authors with the support of Carl Zeiss (Oberkochen, Germany). SSN++ is connected to a Polaris infrared camera (Northern Digital, Waterloo, Ontario, Canada) and to a Minolta VI 900 3D digitizer (Tokyo, Japan) for high-resolution laser scanning. Minimal differences in shape between the laser scan surface and the surface generated from the CT data set could be detected. Nevertheless, high-resolution laser scan of the skin surface allows for a precise patient registration (mean deviation 1.1 mm, maximum deviation 1.8 mm). Radiation load, logistic costs, and efforts arising from the planning of computer-assisted surgery of the head can be reduced because native (markerless) CT data sets can be used for laser scan-based surface registration.

TU-AB-202-06: Quantitative Evaluation of Deformable Image Registration in MRI-Guided Adaptive Radiation Therapy

International Nuclear Information System (INIS)

Mooney, K; Zhao, T; Green, O; Mutic, S; Yang, D; Duan, Y; Zhang, M

2016-01-01

Purpose: To assess the performance of the deformable image registration algorithm used for MRI-guided adaptive radiation therapy using image feature analysis. Methods: MR images were collected from five patients treated on the MRIdian (ViewRay, Inc., Oakwood Village, OH), a three head Cobalt-60 therapy machine with an 0.35 T MR system. The images were acquired immediately prior to treatment with a uniform 1.5 mm resolution. Treatment sites were as follows: head/neck, lung, breast, stomach, and bladder. Deformable image registration was performed using the ViewRay software between the first fraction MRI and the final fraction MRI, and the DICE similarity coefficient (DSC) for the skin contours was reported. The SIFT and Harris feature detection and matching algorithms identified point features in each image separately, then found matching features in the other image. The target registration error (TRE) was defined as the vector distance between matched features on the two image sets. Each deformation was evaluated based on comparison of average TRE and DSC. Results: Image feature analysis produced between 2000–9500 points for evaluation on the patient images. The average (± standard deviation) TRE for all patients was 3.3 mm (±3.1 mm), and the passing rate of TRE<3 mm was 60% on the images. The head/neck patient had the best average TRE (1.9 mm±2.3 mm) and the best passing rate (80%). The lung patient had the worst average TRE (4.8 mm±3.3 mm) and the worst passing rate (37.2%). DSC was not significantly correlated with either TRE (p=0.63) or passing rate (p=0.55). Conclusions: Feature matching provides a quantitative assessment of deformable image registration, with a large number of data points for analysis. The TRE of matched features can be used to evaluate the registration of many objects throughout the volume, whereas DSC mainly provides a measure of gross overlap. We have a research agreement with ViewRay Inc.

TU-AB-202-06: Quantitative Evaluation of Deformable Image Registration in MRI-Guided Adaptive Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Mooney, K; Zhao, T; Green, O; Mutic, S; Yang, D [Washington University School of Medicine, Saint Louis, MO (United States); Duan, Y [University of Missouri, Columbia, Missouri (United States); Zhang, M [Oregon Health and Science University, Portland, Oregon (United States)

2016-06-15

Purpose: To assess the performance of the deformable image registration algorithm used for MRI-guided adaptive radiation therapy using image feature analysis. Methods: MR images were collected from five patients treated on the MRIdian (ViewRay, Inc., Oakwood Village, OH), a three head Cobalt-60 therapy machine with an 0.35 T MR system. The images were acquired immediately prior to treatment with a uniform 1.5 mm resolution. Treatment sites were as follows: head/neck, lung, breast, stomach, and bladder. Deformable image registration was performed using the ViewRay software between the first fraction MRI and the final fraction MRI, and the DICE similarity coefficient (DSC) for the skin contours was reported. The SIFT and Harris feature detection and matching algorithms identified point features in each image separately, then found matching features in the other image. The target registration error (TRE) was defined as the vector distance between matched features on the two image sets. Each deformation was evaluated based on comparison of average TRE and DSC. Results: Image feature analysis produced between 2000–9500 points for evaluation on the patient images. The average (± standard deviation) TRE for all patients was 3.3 mm (±3.1 mm), and the passing rate of TRE<3 mm was 60% on the images. The head/neck patient had the best average TRE (1.9 mm±2.3 mm) and the best passing rate (80%). The lung patient had the worst average TRE (4.8 mm±3.3 mm) and the worst passing rate (37.2%). DSC was not significantly correlated with either TRE (p=0.63) or passing rate (p=0.55). Conclusions: Feature matching provides a quantitative assessment of deformable image registration, with a large number of data points for analysis. The TRE of matched features can be used to evaluate the registration of many objects throughout the volume, whereas DSC mainly provides a measure of gross overlap. We have a research agreement with ViewRay Inc.

Evaluation of body-wise and organ-wise registrations for abdominal organs

Science.gov (United States)

Xu, Zhoubing; Panjwani, Sahil A.; Lee, Christopher P.; Burke, Ryan P.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Abramson, Richard G.; Landman, Bennett A.

2016-03-01

Identifying cross-sectional and longitudinal correspondence in the abdomen on computed tomography (CT) scans is necessary for quantitatively tracking change and understanding population characteristics, yet abdominal image registration is a challenging problem. The key difficulty in solving this problem is huge variations in organ dimensions and shapes across subjects. The current standard registration method uses the global or body-wise registration technique, which is based on the global topology for alignment. This method (although producing decent results) has substantial influence of outliers, thus leaving room for significant improvement. Here, we study a new image registration approach using local (organ-wise registration) by first creating organ-specific bounding boxes and then using these regions of interest (ROIs) for aligning references to target. Based on Dice Similarity Coefficient (DSC), Mean Surface Distance (MSD) and Hausdorff Distance (HD), the organ-wise approach is demonstrated to have significantly better results by minimizing the distorting effects of organ variations. This paper compares exclusively the two registration methods by providing novel quantitative and qualitative comparison data and is a subset of the more comprehensive problem of improving the multi-atlas segmentation by using organ normalization.

An evaluation of approaches used to teach quality improvement to pre-registration healthcare professionals: An integrative review.

Science.gov (United States)

Armstrong, Lorraine; Shepherd, Ashley; Harris, Fiona

2017-08-01

Improving the quality of healthcare remains central to UK and international policy, practice and research. In 2003, The Institute of Medicine's 'Health Professions Education: A Bridge to Quality', advocated quality improvement as a core competency for all healthcare professionals. As a result, developing capacity and capability of those applying improvement methodologies in the pre-registration population has risen, yet, little is known about the teaching approaches employed for this purpose. To describe and analyse educational approaches used to teach quality improvement to pre-registration healthcare professionals and identify enabling and impeding factors. Integrative review. CINAHL, PsychINFO, MEDLINE, ERIC, ASSIA, SCOPUS and Google Scholar were accessed for papers published between 2000 and 2016. Publications where quality improvement education was delivered to pre-registration healthcare professionals were eligible. One author independently screened papers, extracted data using a modified version of the Reporting of Primary Studies in Education Guideline and evaluated methodological quality using the Weight of Evidence Framework. The Kirkpatrick Education Evaluation Model was used to explore the impact of teaching approaches. Enabling and impeding factors were thematically analysed. A narrative synthesis of findings is presented. Ten papers were included, representing nursing, pharmacy and medicine from UK, Norway and USA. Studies comprised four quantitative, four mixed method, one qualitative and one cluster randomised trial, all allocated medium Weight of Evidence. Teaching approaches included experiential learning cited in all studies, didactics in seven, group work in four, seminars in three, self-directed learning in three and simulation in one. Most studies measured Level 1 of the Kirkpatrick Model (reaction), all but one measured Level 2 (skills, knowledge or attitudes), none measured Level 3 (behaviour) and one measured Level 4 (patient outcomes

Numerical methods for image registration

CERN Document Server

Modersitzki, Jan

2003-01-01

Based on the author's lecture notes and research, this well-illustrated and comprehensive text is one of the first to provide an introduction to image registration with particular emphasis on numerical methods in medical imaging. Ideal for researchers in industry and academia, it is also a suitable study guide for graduate mathematicians, computer scientists, engineers, medical physicists, and radiologists.Image registration is utilised whenever information obtained from different viewpoints needs to be combined or compared and unwanted distortion needs to be eliminated. For example, CCTV imag

Registration of the cancer

International Nuclear Information System (INIS)

Morales, F.; Campos, X.

2002-01-01

A database for the registration of the cancer was designed in ambient access, of the Microsoft Office, to take the registrations at national level. With this database the statistics will be obtained about the incidence of the cancer in the population, evaluation of the sanitary services of prevention, diagnose and treatment of the illness, etc. The used codes are according to the listings of code of the Ministry of Health (MINSA) and OPS

Clinical trial registration in oral health journals.

Science.gov (United States)

Smaïl-Faugeron, V; Fron-Chabouis, H; Durieux, P

2015-03-01

Prospective registration of randomized controlled trials (RCTs) represents the best solution to reporting bias. The extent to which oral health journals have endorsed and complied with RCT registration is unknown. We identified journals publishing RCTs in dentistry, oral surgery, and medicine in the Journal Citation Reports. We classified journals into 3 groups: journals requiring or recommending trial registration, journals referring indirectly to registration, and journals providing no reference to registration. For the 5 journals with the highest 2012 impact factors in each group, we assessed whether RCTs with results published in 2013 had been registered. Of 78 journals examined, 32 (41%) required or recommended trial registration, 19 (24%) referred indirectly to registration, and 27 (35%) provided no reference to registration. We identified 317 RCTs with results published in the 15 selected journals in 2013. Overall, 73 (23%) were registered in a trial registry. Among those, 91% were registered retrospectively and 32% did not report trial registration in the published article. The proportion of trials registered was not significantly associated with editorial policies: 29% with results in journals that required or recommended registration, 15% in those that referred indirectly to registration, and 21% in those providing no reference to registration (P = 0.05). Less than one-quarter of RCTs with results published in a sample of oral health journals were registered with a public registry. Improvements are needed with respect to how journals inform and require their authors to register their trials. © International & American Associations for Dental Research.

Geo-registration of Unprofessional and Weakly-related Image and Precision Evaluation

Directory of Open Access Journals (Sweden)

LIU Yingzhen

2015-09-01

Full Text Available The 3D geo-spatial model built by unprofessional and weakly-related image is a significant source of geo-spatial information. The unprofessional and weakly-related image cannot be useful geo-spatial information until be geo-registered with accurate geo-spatial orientation and location. In this paper, we present an automatic geo-registration using the coordination acquired by real-time GPS module. We calculate 2D and 3D spatial transformation parameters based on the spatial similarity between the image location in the geo-spatial coordination system and in the 3D reconstruction coordination system. Because of the poor precision of GPS information and especially the unstability of elevation measurement, we use RANSAC algorithm to get rid of outliers. In the experiment, we compare the geo-registered image positions to their differential GPS coordinates. The errors of translation, rotation and scaling are evaluated quantitively and the causes of bad result are analyzed. The experiment demonstrates that this geo-registration method can get a precise result with enough images.

Consistency of parametric registration in serial MRI studies of brain tumor progression

International Nuclear Information System (INIS)

Mang, Andreas; Buzug, Thorsten M.; Schnabel, Julia A.; Crum, William R.; Modat, Marc; Ourselin, Sebastien; Hawkes, David J.; Camara-Rey, Oscar; Palm, Christoph; Caseiras, Gisele Brasil; Jaeger, H.R.

2008-01-01

The consistency of parametric registration in multi-temporal magnetic resonance (MR) imaging studies was evaluated. Serial MRI scans of adult patients with a brain tumor (glioma) were aligned by parametric registration. The performance of low-order spatial alignment (6/9/12 degrees of freedom) of different 3D serial MR-weighted images is evaluated. A registration protocol for the alignment of all images to one reference coordinate system at baseline is presented. Registration results were evaluated for both, multimodal intra-timepoint and mono-modal multi-temporal registration. The latter case might present a challenge to automatic intensity-based registration algorithms due to ill-defined correspondences. The performance of our algorithm was assessed by testing the inverse registration consistency. Four different similarity measures were evaluated to assess consistency. Careful visual inspection suggests that images are well aligned, but their consistency may be imperfect. Sub-voxel inconsistency within the brain was found for allsimilarity measures used for parametric multi-temporal registration. T1-weighted images were most reliable for establishing spatial correspondence between different timepoints. The parametric registration algorithm is feasible for use in this application. The sub-voxel resolution mean displacement error of registration transformations demonstrates that the algorithm converges to an almost identical solution for forward and reverse registration. (orig.)

Evaluation of registration strategies for multi-modality images of rat brain slices

International Nuclear Information System (INIS)

Palm, Christoph; Vieten, Andrea; Salber, Dagmar; Pietrzyk, Uwe

2009-01-01

In neuroscience, small-animal studies frequently involve dealing with series of images from multiple modalities such as histology and autoradiography. The consistent and bias-free restacking of multi-modality image series is obligatory as a starting point for subsequent non-rigid registration procedures and for quantitative comparisons with positron emission tomography (PET) and other in vivo data. Up to now, consistency between 2D slices without cross validation using an inherent 3D modality is frequently presumed to be close to the true morphology due to the smooth appearance of the contours of anatomical structures. However, in multi-modality stacks consistency is difficult to assess. In this work, consistency is defined in terms of smoothness of neighboring slices within a single modality and between different modalities. Registration bias denotes the distortion of the registered stack in comparison to the true 3D morphology and shape. Based on these metrics, different restacking strategies of multi-modality rat brain slices are experimentally evaluated. Experiments based on MRI-simulated and real dual-tracer autoradiograms reveal a clear bias of the restacked volume despite quantitatively high consistency and qualitatively smooth brain structures. However, different registration strategies yield different inter-consistency metrics. If no genuine 3D modality is available, the use of the so-called SOP (slice-order preferred) or MOSOP (modality-and-slice-order preferred) strategy is recommended.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

Science.gov (United States)

Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

2013-01-01

The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Registration of 3D ultrasound computer tomography and MRI for evaluation of tissue correspondences

Science.gov (United States)

Hopp, T.; Dapp, R.; Zapf, M.; Kretzek, E.; Gemmeke, H.; Ruiter, N. V.

2015-03-01

3D Ultrasound Computer Tomography (USCT) is a new imaging method for breast cancer diagnosis. In the current state of development it is essential to correlate USCT with a known imaging modality like MRI to evaluate how different tissue types are depicted. Due to different imaging conditions, e.g. with the breast subject to buoyancy in USCT, a direct correlation is demanding. We present a 3D image registration method to reduce positioning differences and allow direct side-by-side comparison of USCT and MRI volumes. It is based on a two-step approach including a buoyancy simulation with a biomechanical model and free form deformations using cubic B-Splines for a surface refinement. Simulation parameters are optimized patient-specifically in a simulated annealing scheme. The method was evaluated with in-vivo datasets resulting in an average registration error below 5mm. Correlating tissue structures can thereby be located in the same or nearby slices in both modalities and three-dimensional non-linear deformations due to the buoyancy are reduced. Image fusion of MRI volumes and USCT sound speed volumes was performed for intuitive display. By applying the registration to data of our first in-vivo study with the KIT 3D USCT, we could correlate several tissue structures in MRI and USCT images and learn how connective tissue, carcinomas and breast implants observed in the MRI are depicted in the USCT imaging modes.

Study of national registration systems for health records of radiation workers. National radiation dose registration system

International Nuclear Information System (INIS)

Nakagawa, Haruo; Kanda, Keiji

1999-01-01

A national radiation dose registration system is proposed in this paper. In Japan, only one radiation dose registration system is partly effective. It is applied for workers in nuclear power plants which are under control of regulatory laws for nuclear reactors. The total system was proposed previously by the Committee for Compensation Claims of Nuclear Accidents. The reason for the delay in establishing a registration system for all radiation workers is supposedly a lack of effort to adjust differences among items in radiation protection laws and the promotion of public acceptance to atomic power. Items about dose recordings, record keeping and dose-record reporting in all of the radiation regulatory laws are compared to each other, and items were extracted for revision. (author)

Surface membrane based bladder registration for evaluation of accumulated dose during brachytherapy in cervical cancer

DEFF Research Database (Denmark)

Noe, Karsten Østergaard; Tanderup, Kari; Sørensen, Thomas Sangild

2011-01-01

of the fixed surface. Optional landmark based matches can be included in the suggested iterative solver. The technique is demonstrated for bladder registration in brachytherapy treatment evaluation of cervical cancer. It holds promise to better estimate the accumulated but unintentional dose delivered...

Victoria's review of registration for health practitioners.

Science.gov (United States)

Scotts, H; Carter, M

1988-01-01

This article discusses some of the issues raised in the Interim Report of the current Review of Registration of Health Practitioners being conducted for the Victorian Health Department. The Report attempts to develop the framework in which the registration Boards will operate as part of a cohesive registration system. It proposed a mechanism and criteria for the registration of new groups as well as principles which can be applied to the ongoing review of each existing Board. The Review takes the perspective that registration of health practitioners carries with it both advantages and disadvantages for the general community. Under the proposed new system the controls exercised over health care providers by Registration Boards would be evaluated on the basis of to what extent the benefits to the public outweighed the potential costs. It is in this context that the Report addresses issues such as consumer complaints handling, registration of individual practitioners and controls over professional advertising and other business practices.

Estimation of lung motion fields in 4D CT data by variational non-linear intensity-based registration: A comparison and evaluation study

International Nuclear Information System (INIS)

Werner, René; Schmidt-Richberg, Alexander; Handels, Heinz; Ehrhardt, Jan

2014-01-01

Accurate and robust estimation of motion fields in respiration-correlated CT (4D CT) images, usually performed by non-linear registration of the temporal CT frames, is a precondition for the analysis of patient-specific breathing dynamics and subsequent image-supported diagnostics and treatment planning. In this work, we present a comprehensive comparison and evaluation study of non-linear registration variants applied to the task of lung motion estimation in thoracic 4D CT data. In contrast to existing multi-institutional comparison studies (e.g. MIDRAS and EMPIRE10), we focus on the specific but common class of variational intensity-based non-parametric registration and analyze the impact of the different main building blocks of the underlying optimization problem: the distance measure to be minimized, the regularization approach and the transformation space considered during optimization. In total, 90 different combinations of building block instances are compared. Evaluated on proprietary and publicly accessible 4D CT images, landmark-based registration errors (TRE) between 1.14 and 1.20 mm for the most accurate registration variants demonstrate competitive performance of the applied general registration framework compared to other state-of-the-art approaches for lung CT registration. Although some specific trends can be observed, effects of interchanging individual instances of the building blocks on the TRE are in general rather small (no single outstanding registration variant existing); the same level of accuracy is, however, associated with significantly different degrees of motion field smoothness and computational demands. Consequently, the building block combination of choice will depend on application-specific requirements on motion field characteristics. (paper)

Feasibility of Multimodal Deformable Registration for Head and Neck Tumor Treatment Planning

Energy Technology Data Exchange (ETDEWEB)

Fortunati, Valerio, E-mail: v.fortunati@erasmusmc.nl [Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC University Medical Center, Rotterdam (Netherlands); Verhaart, René F. [Hyperthermia Unit, Department of Radiation Oncology, Erasmus MC University Medical Center Cancer Institute, Rotterdam (Netherlands); Angeloni, Francesco [Istituto di Ricovero e Cura a Carattere Scientifico Foundation SDN for Research and High Education in Nuclear Diagnostics, Naples (Italy); Lugt, Aad van der [Department of Radiology, Erasmus MC University Medical Center, Rotterdam (Netherlands); Niessen, Wiro J. [Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC University Medical Center, Rotterdam (Netherlands); Faculty of Applied Sciences, Delft University of Technology, Delft (Netherlands); Veenland, Jifke F. [Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC University Medical Center, Rotterdam (Netherlands); Paulides, Margarethus M. [Hyperthermia Unit, Department of Radiation Oncology, Erasmus MC University Medical Center Cancer Institute, Rotterdam (Netherlands); Walsum, Theo van [Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC University Medical Center, Rotterdam (Netherlands)

2014-09-01

Purpose: To investigate the feasibility of using deformable registration in clinical practice to fuse MR and CT images of the head and neck for treatment planning. Method and Materials: A state-of-the-art deformable registration algorithm was optimized, evaluated, and compared with rigid registration. The evaluation was based on manually annotated anatomic landmarks and regions of interest in both modalities. We also developed a multiparametric registration approach, which simultaneously aligns T1- and T2-weighted MR sequences to CT. This was evaluated and compared with single-parametric approaches. Results: Our results show that deformable registration yielded a better accuracy than rigid registration, without introducing unrealistic deformations. For deformable registration, an average landmark alignment of approximatively 1.7 mm was obtained. For all the regions of interest excluding the cerebellum and the parotids, deformable registration provided a median modified Hausdorff distance of approximatively 1 mm. Similar accuracies were obtained for the single-parameter and multiparameter approaches. Conclusions: This study demonstrates that deformable registration of head-and-neck CT and MR images is feasible, with overall a significanlty higher accuracy than for rigid registration.

Feasibility of Multimodal Deformable Registration for Head and Neck Tumor Treatment Planning

International Nuclear Information System (INIS)

Fortunati, Valerio; Verhaart, René F.; Angeloni, Francesco; Lugt, Aad van der; Niessen, Wiro J.; Veenland, Jifke F.; Paulides, Margarethus M.; Walsum, Theo van

2014-01-01

Purpose: To investigate the feasibility of using deformable registration in clinical practice to fuse MR and CT images of the head and neck for treatment planning. Method and Materials: A state-of-the-art deformable registration algorithm was optimized, evaluated, and compared with rigid registration. The evaluation was based on manually annotated anatomic landmarks and regions of interest in both modalities. We also developed a multiparametric registration approach, which simultaneously aligns T1- and T2-weighted MR sequences to CT. This was evaluated and compared with single-parametric approaches. Results: Our results show that deformable registration yielded a better accuracy than rigid registration, without introducing unrealistic deformations. For deformable registration, an average landmark alignment of approximatively 1.7 mm was obtained. For all the regions of interest excluding the cerebellum and the parotids, deformable registration provided a median modified Hausdorff distance of approximatively 1 mm. Similar accuracies were obtained for the single-parameter and multiparameter approaches. Conclusions: This study demonstrates that deformable registration of head-and-neck CT and MR images is feasible, with overall a significanlty higher accuracy than for rigid registration

Study of three-dimensional PET and MR image registration based on higher-order mutual information

International Nuclear Information System (INIS)

Ren Haiping; Chen Shengzu; Wu Wenkai; Yang Hu

2002-01-01

Mutual information has currently been one of the most intensively researched measures. It has been proven to be accurate and effective registration measure. Despite the general promising results, mutual information sometimes might lead to misregistration because of neglecting spatial information and treating intensity variations with undue sensitivity. An extension of mutual information framework was proposed in which higher-order spatial information regarding image structures was incorporated into the registration processing of PET and MR. The second-order estimate of mutual information algorithm was applied to the registration of seven patients. Evaluation from Vanderbilt University and authors' visual inspection showed that sub-voxel accuracy and robust results were achieved in all cases with second-order mutual information as the similarity measure and with Powell's multidimensional direction set method as optimization strategy

Error estimation of deformable image registration of pulmonary CT scans using convolutional neural networks.

Science.gov (United States)

Eppenhof, Koen A J; Pluim, Josien P W

2018-04-01

Error estimation in nonlinear medical image registration is a nontrivial problem that is important for validation of registration methods. We propose a supervised method for estimation of registration errors in nonlinear registration of three-dimensional (3-D) images. The method is based on a 3-D convolutional neural network that learns to estimate registration errors from a pair of image patches. By applying the network to patches centered around every voxel, we construct registration error maps. The network is trained using a set of representative images that have been synthetically transformed to construct a set of image pairs with known deformations. The method is evaluated on deformable registrations of inhale-exhale pairs of thoracic CT scans. Using ground truth target registration errors on manually annotated landmarks, we evaluate the method's ability to estimate local registration errors. Estimation of full domain error maps is evaluated using a gold standard approach. The two evaluation approaches show that we can train the network to robustly estimate registration errors in a predetermined range, with subvoxel accuracy. We achieved a root-mean-square deviation of 0.51 mm from gold standard registration errors and of 0.66 mm from ground truth landmark registration errors.

SU-E-J-112: Intensity-Based Pulmonary Image Registration: An Evaluation Study

Energy Technology Data Exchange (ETDEWEB)

Yang, F; Meyer, J; Sandison, G [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States)

2015-06-15

Purpose: Accurate alignment of thoracic CT images is essential for dose tracking and to safely implement adaptive radiotherapy in lung cancers. At the same time it is challenging given the highly elastic nature of lung tissue deformations. The objective of this study was to assess the performances of three state-of-art intensity-based algorithms in terms of their ability to register thoracic CT images subject to affine, barrel, and sinusoid transformation. Methods: Intensity similarity measures of the evaluated algorithms contained sum-of-squared difference (SSD), local mutual information (LMI), and residual complexity (RC). Five thoracic CT scans obtained from the EMPIRE10 challenge database were included and served as reference images. Each CT dataset was distorted by realistic affine, barrel, and sinusoid transformations. Registration performances of the three algorithms were evaluated for each distortion type in terms of intensity root mean square error (IRMSE) between the reference and registered images in the lung regions. Results: For affine distortions, the three algorithms differed significantly in registration of thoracic images both visually and nominally in terms of IRMSE with a mean of 0.011 for SSD, 0.039 for RC, and 0.026 for LMI (p<0.01; Kruskal-Wallis test). For barrel distortion, the three algorithms showed nominally no significant difference in terms of IRMSE with a mean of 0.026 for SSD, 0.086 for RC, and 0.054 for LMI (p=0.16) . A significant difference was seen for sinusoid distorted thoracic CT data with mean lung IRMSE of 0.039 for SSD, 0.092 for RC, and 0.035 for LMI (p=0.02). Conclusion: Pulmonary deformations might vary to a large extent in nature in a daily clinical setting due to factors ranging from anatomy variations to respiratory motion to image quality. It can be appreciated from the results of the present study that the suitability of application of a particular algorithm for pulmonary image registration is deformation-dependent.

Registration status and outcome reporting of trials published in core headache medicine journals.

Science.gov (United States)

Rayhill, Melissa L; Sharon, Roni; Burch, Rebecca; Loder, Elizabeth

2015-11-17

To evaluate randomized controlled trial (RCT) registration and outcome reporting compliance in core headache medicine journals. We identified RCTs published in core journals (Headache, Cephalalgia, and the Journal of Headache and Pain) from 2005 through 2014. We searched articles for trial registration numbers, which were verified in the corresponding trial registry. We categorized trial funding sources as industry, academic, government, or mixed. We contacted corresponding authors to assess reasons for nonregistration. We evaluated whether primary outcomes in trial registries matched those in corresponding publications. The journals published 225 RCTs over the study period. Fifty-eight of 225 (26%) reported a trial registration number in the article that could be linked to a corresponding registry entry. Trial registration rates increased over the 9 years of the study. Forty-six of 118 (39%) of industry-funded studies were registered compared with 27% of academic and 0% of government-funded studies. Only 5% of RCTs were prospectively registered, reported primary outcomes identical to those in the trial registry, and did not report unacknowledged post hoc outcomes. The most common reason for nonregistration was lack of awareness. Only about a quarter of the articles published in the core headache medicine journals are compliant with trial registration, but compliance has increased over time. Selective reporting of outcomes remains a problem, and very few trials met all 3 reporting standards assessed in this study. Efforts to improve the quality of trial reporting in the headache literature should continue. © 2015 American Academy of Neurology.

17 CFR 240.15b6-1 - Withdrawal from registration.

Science.gov (United States)

2010-04-01

... Registration Depository (operated by the Financial Industry Regulatory Authority, Inc.) in accordance with...) to update any inaccurate information. (b) A notice of withdrawal from registration filed by a broker... public interest or for the protection of investors, or within such shorter period of time as the...

Behaviors study of image registration algorithms in image guided radiation therapy

International Nuclear Information System (INIS)

Zou Lian; Hou Qing

2008-01-01

Objective: Study the behaviors of image registration algorithms, and analyze the elements which influence the performance of image registrations. Methods: Pre-known corresponding coordinates were appointed for reference image and moving image, and then the influence of region of interest (ROI) selection, transformation function initial parameters and coupled parameter spaces on registration results were studied with a software platform developed in home. Results: Region of interest selection had a manifest influence on registration performance. An improperly chosen ROI resulted in a bad registration. Transformation function initial parameters selection based on pre-known information could improve the accuracy of image registration. Coupled parameter spaces would enhance the dependence of image registration algorithm on ROI selection. Conclusions: It is necessary for clinic IGRT to obtain a ROI selection strategy (depending on specific commercial software) correlated to tumor sites. Three suggestions for image registration technique developers are automatic selection of the initial parameters of transformation function based on pre-known information, developing specific image registration algorithm for specific image feature, and assembling real-time image registration algorithms according to tumor sites selected by software user. (authors)

Registration of Laser Scanning Point Clouds: A Review

Science.gov (United States)

Cheng, Liang; Chen, Song; Xu, Hao; Wu, Yang; Li, Manchun

2018-01-01

The integration of multi-platform, multi-angle, and multi-temporal LiDAR data has become important for geospatial data applications. This paper presents a comprehensive review of LiDAR data registration in the fields of photogrammetry and remote sensing. At present, a coarse-to-fine registration strategy is commonly used for LiDAR point clouds registration. The coarse registration method is first used to achieve a good initial position, based on which registration is then refined utilizing the fine registration method. According to the coarse-to-fine framework, this paper reviews current registration methods and their methodologies, and identifies important differences between them. The lack of standard data and unified evaluation systems is identified as a factor limiting objective comparison of different methods. The paper also describes the most commonly-used point cloud registration error analysis methods. Finally, avenues for future work on LiDAR data registration in terms of applications, data, and technology are discussed. In particular, there is a need to address registration of multi-angle and multi-scale data from various newly available types of LiDAR hardware, which will play an important role in diverse applications such as forest resource surveys, urban energy use, cultural heritage protection, and unmanned vehicles.

Modeling cancer registration processes with an enhanced activity diagram.

Science.gov (United States)

Lyalin, D; Williams, W

2005-01-01

Adequate instruments are needed to reflect the complexity of routine cancer registry operations properly in a business model. The activity diagram is a key instrument of the Unified Modeling Language (UML) for the modeling of business processes. The authors aim to improve descriptions of processes in cancer registration, as well as in other public health domains, through the enhancements of an activity diagram notation within the standard semantics of UML. The authors introduced the practical approach to enhance a conventional UML activity diagram, complementing it with the following business process concepts: timeline, duration for individual activities, responsibilities for individual activities within swimlanes, and descriptive text. The authors used an enhanced activity diagram for modeling surveillance processes in the cancer registration domain. Specific example illustrates the use of an enhanced activity diagram to visualize a process of linking cancer registry records with external mortality files. Enhanced activity diagram allows for the addition of more business concepts to a single diagram and can improve descriptions of processes in cancer registration, as well as in other domains. Additional features of an enhanced activity diagram allow to advance the visualization of cancer registration processes. That, in turn, promotes the clarification of issues related to the process timeline, responsibilities for particular operations, and collaborations among process participants. Our first experiences in a cancer registry best practices development workshop setting support the usefulness of such an approach.

TU-F-17A-03: A 4D Lung Phantom for Coupled Registration/Segmentation Evaluation

International Nuclear Information System (INIS)

Markel, D; El Naqa, I; Levesque, I

2014-01-01

Purpose: Coupling the processes of segmentation and registration (regmentation) is a recent development that allows improved efficiency and accuracy for both steps and may improve the clinical feasibility of online adaptive radiotherapy. Presented is a multimodality animal tissue model designed specifically to provide a ground truth to simultaneously evaluate segmentation and registration errors during respiratory motion. Methods: Tumor surrogates were constructed from vacuum sealed hydrated natural sea sponges with catheters used for the injection of PET radiotracer. These contained two compartments allowing for two concentrations of radiotracer mimicking both tumor and background signals. The lungs were inflated to different volumes using an air pump and flow valve and scanned using PET/CT and MRI. Anatomical landmarks were used to evaluate the registration accuracy using an automated bifurcation tracking pipeline for reproducibility. The bifurcation tracking accuracy was assessed using virtual deformations of 2.6 cm, 5.2 cm and 7.8 cm of a CT scan of a corresponding human thorax. Bifurcations were detected in the deformed dataset and compared to known deformation coordinates for 76 points. Results: The bifurcation tracking accuracy was found to have a mean error of −0.94, 0.79 and −0.57 voxels in the left-right, anterior-posterior and inferior-superior axes using a 1×1×5 mm3 resolution after the CT volume was deformed 7.8 cm. The tumor surrogates provided a segmentation ground truth after being registered to the phantom image. Conclusion: A swine lung model in conjunction with vacuum sealed sponges and a bifurcation tracking algorithm is presented that is MRI, PET and CT compatible and anatomically and kinetically realistic. Corresponding software for tracking anatomical landmarks within the phantom shows sub-voxel accuracy. Vacuum sealed sponges provide realistic tumor surrogate with a known boundary. A ground truth with minimal uncertainty is thus

Development and experimental evaluation of an automatic marker registration system for tracking of augmented reality

International Nuclear Information System (INIS)

Yan, Wei-da; Yang Shou-feng; Ishii, Hirotake; Shimoda, Hiroshi; Izumi, Masanori

2010-01-01

In order to apply augmented reality in plant maintenance activities it is necessary to use real-time high accuracy tracking technology. One of the most efficient tracking methods is using paper-based markers and computing the relative position and orientation between a vision sensor (camera) and the markers through image processing and geometry calculations. In this method, the 3D-position of each marker is needed before tracking, but it is inefficient to measure all the markers manually. In this study, an automatic marker registration system was developed so as to measure the 3D-position of each marker automatically. The system is composed of a camera, a laser rangefinder and a motion base, which is used to control the pose of the laser rangefinder. A computer, connected to them, is used for controlling the system and for data transport. The results of the experimental evaluations show that the measurement takes about 21 seconds per marker and that the Root Mean Square Error (RMSE) of the position measurements is 3.5 mm. The feasibility evaluation of the system was conducted in Fugen nuclear plant. The results show that the system can largely reduce the preparatory workload of an AR application in a Nuclear Power Plant (NPP). (author)

Third molar development: evaluation of nine tooth development registration techniques for age estimations.

Science.gov (United States)

Thevissen, Patrick W; Fieuws, Steffen; Willems, Guy

2013-03-01

Multiple third molar development registration techniques exist. Therefore the aim of this study was to detect which third molar development registration technique was most promising to use as a tool for subadult age estimation. On a collection of 1199 panoramic radiographs the development of all present third molars was registered following nine different registration techniques [Gleiser, Hunt (GH); Haavikko (HV); Demirjian (DM); Raungpaka (RA); Gustafson, Koch (GK); Harris, Nortje (HN); Kullman (KU); Moorrees (MO); Cameriere (CA)]. Regression models with age as response and the third molar registration as predictor were developed for each registration technique separately. The MO technique disclosed highest R(2) (F 51%, M 45%) and lowest root mean squared error (F 3.42 years; M 3.67 years) values, but differences with other techniques were small in magnitude. The amount of stages utilized in the explored staging techniques slightly influenced the age predictions. © 2013 American Academy of Forensic Sciences.

Canny edge-based deformable image registration.

Science.gov (United States)

Kearney, Vasant; Huang, Yihui; Mao, Weihua; Yuan, Baohong; Tang, Liping

2017-02-07

This work focuses on developing a 2D Canny edge-based deformable image registration (Canny DIR) algorithm to register in vivo white light images taken at various time points. This method uses a sparse interpolation deformation algorithm to sparsely register regions of the image with strong edge information. A stability criterion is enforced which removes regions of edges that do not deform in a smooth uniform manner. Using a synthetic mouse surface ground truth model, the accuracy of the Canny DIR algorithm was evaluated under axial rotation in the presence of deformation. The accuracy was also tested using fluorescent dye injections, which were then used for gamma analysis to establish a second ground truth. The results indicate that the Canny DIR algorithm performs better than rigid registration, intensity corrected Demons, and distinctive features for all evaluation matrices and ground truth scenarios. In conclusion Canny DIR performs well in the presence of the unique lighting and shading variations associated with white-light-based image registration.

Object-constrained meshless deformable algorithm for high speed 3D nonrigid registration between CT and CBCT

International Nuclear Information System (INIS)

Chen Ting; Kim, Sung; Goyal, Sharad; Jabbour, Salma; Zhou Jinghao; Rajagopal, Gunaretnum; Haffty, Bruce; Yue Ning

2010-01-01

Purpose: High-speed nonrigid registration between the planning CT and the treatment CBCT data is critical for real time image guided radiotherapy (IGRT) to improve the dose distribution and to reduce the toxicity to adjacent organs. The authors propose a new fully automatic 3D registration framework that integrates object-based global and seed constraints with the grayscale-based ''demons'' algorithm. Methods: Clinical objects were segmented on the planning CT images and were utilized as meshless deformable models during the nonrigid registration process. The meshless models reinforced a global constraint in addition to the grayscale difference between CT and CBCT in order to maintain the shape and the volume of geometrically complex 3D objects during the registration. To expedite the registration process, the framework was stratified into hierarchies, and the authors used a frequency domain formulation to diffuse the displacement between the reference and the target in each hierarchy. Also during the registration of pelvis images, they replaced the air region inside the rectum with estimated pixel values from the surrounding rectal wall and introduced an additional seed constraint to robustly track and match the seeds implanted into the prostate. The proposed registration framework and algorithm were evaluated on 15 real prostate cancer patients. For each patient, prostate gland, seminal vesicle, bladder, and rectum were first segmented by a radiation oncologist on planning CT images for radiotherapy planning purpose. The same radiation oncologist also manually delineated the tumor volumes and critical anatomical structures in the corresponding CBCT images acquired at treatment. These delineated structures on the CBCT were only used as the ground truth for the quantitative validation, while structures on the planning CT were used both as the input to the registration method and the ground truth in validation. By registering the planning CT to the CBCT, a

The evaluation of composite dose using deformable image registration in adaptive radiotherapy for head and neck cancer

International Nuclear Information System (INIS)

Hwang, Chul Hwan; Ko, Seong Jin; Kim, Chang Soo; Kim, Jung Hoon; Kim, Dong Hyun; Choi, Seok Yoon; Ye, Soo Young; Kang, Se Sik

2013-01-01

In adaptive radiotherapy(ART), generated composite dose of surrounding normal tissue on overall treatment course which is using deformable image registration from multistage images. Also, compared with doses summed by each treatment plan and clinical significance is considered. From the first of May, 2011 to the last of July, 2012. Patients who were given treatment and had the head and neck cancer with 3-dimension conformal radiotherapy or intensity modulated radiotherapy, those who were carried out adaptive radiotherapy cause of tumor shrinkage and weight loss. Generated composite dose of surrounding normal tissue using deformable image registration was been possible, statistically significant difference was showed to mandible(48.95±3.89 vs 49.10±3.55 Gy), oral cavity(36.93±4.03 vs 38.97±5.08 Gy), parotid gland(35.71±6.22 vs 36.12±6.70 Gy) and temporomandibular joint(18.41±9.60 vs 20.13±10.42 Gy) compared with doses summed by each treatment plan. The results of this study show significant difference between composite dose by deformable image registration and doses summed by each treatment plan, composite dose by deformable image registration may generate more exact evaluation to surrounding normal tissue in adaptive radiotherapy

The evaluation of composite dose using deformable image registration in adaptive radiotherapy for head and neck cancer

Energy Technology Data Exchange (ETDEWEB)

Hwang, Chul Hwan; Ko, Seong Jin; Kim, Chang Soo; Kim, Jung Hoon; Kim, Dong Hyun; Choi, Seok Yoon; Ye, Soo Young; Kang, Se Sik [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Pusan (Korea, Republic of)

2013-09-15

In adaptive radiotherapy(ART), generated composite dose of surrounding normal tissue on overall treatment course which is using deformable image registration from multistage images. Also, compared with doses summed by each treatment plan and clinical significance is considered. From the first of May, 2011 to the last of July, 2012. Patients who were given treatment and had the head and neck cancer with 3-dimension conformal radiotherapy or intensity modulated radiotherapy, those who were carried out adaptive radiotherapy cause of tumor shrinkage and weight loss. Generated composite dose of surrounding normal tissue using deformable image registration was been possible, statistically significant difference was showed to mandible(48.95±3.89 vs 49.10±3.55 Gy), oral cavity(36.93±4.03 vs 38.97±5.08 Gy), parotid gland(35.71±6.22 vs 36.12±6.70 Gy) and temporomandibular joint(18.41±9.60 vs 20.13±10.42 Gy) compared with doses summed by each treatment plan. The results of this study show significant difference between composite dose by deformable image registration and doses summed by each treatment plan, composite dose by deformable image registration may generate more exact evaluation to surrounding normal tissue in adaptive radiotherapy.

Surface-based prostate registration with biomechanical regularization

Science.gov (United States)

van de Ven, Wendy J. M.; Hu, Yipeng; Barentsz, Jelle O.; Karssemeijer, Nico; Barratt, Dean; Huisman, Henkjan J.

2013-03-01

Adding MR-derived information to standard transrectal ultrasound (TRUS) images for guiding prostate biopsy is of substantial clinical interest. A tumor visible on MR images can be projected on ultrasound by using MRUS registration. A common approach is to use surface-based registration. We hypothesize that biomechanical modeling will better control deformation inside the prostate than a regular surface-based registration method. We developed a novel method by extending a surface-based registration with finite element (FE) simulation to better predict internal deformation of the prostate. For each of six patients, a tetrahedral mesh was constructed from the manual prostate segmentation. Next, the internal prostate deformation was simulated using the derived radial surface displacement as boundary condition. The deformation field within the gland was calculated using the predicted FE node displacements and thin-plate spline interpolation. We tested our method on MR guided MR biopsy imaging data, as landmarks can easily be identified on MR images. For evaluation of the registration accuracy we used 45 anatomical landmarks located in all regions of the prostate. Our results show that the median target registration error of a surface-based registration with biomechanical regularization is 1.88 mm, which is significantly different from 2.61 mm without biomechanical regularization. We can conclude that biomechanical FE modeling has the potential to improve the accuracy of multimodal prostate registration when comparing it to regular surface-based registration.

3-D brain image registration using optimal morphological processing

International Nuclear Information System (INIS)

Loncaric, S.; Dhawan, A.P.

1994-01-01

The three-dimensional (3-D) registration of Magnetic Resonance (MR) and Positron Emission Tomographic (PET) images of the brain is important for analysis of the human brain and its diseases. A procedure for optimization of (3-D) morphological structuring elements, based on a genetic algorithm, is presented in the paper. The registration of the MR and PET images is done by means of a registration procedure in two major phases. In the first phase, the Iterative Principal Axis Transform (IPAR) is used for initial registration. In the second phase, the optimal shape description method based on the Morphological Signature Transform (MST) is used for final registration. The morphological processing is used to improve the accuracy of the basic IPAR method. The brain ventricle is used as a landmark for MST registration. A near-optimal structuring element obtained by means of a genetic algorithm is used in MST to describe the shape of the ventricle. The method has been tested on the set of brain images demonstrating the feasibility of approach. (author). 11 refs., 3 figs

Propagation of registration uncertainty during multi-fraction cervical cancer brachytherapy

Science.gov (United States)

Amir-Khalili, A.; Hamarneh, G.; Zakariaee, R.; Spadinger, I.; Abugharbieh, R.

2017-10-01

Multi-fraction cervical cancer brachytherapy is a form of image-guided radiotherapy that heavily relies on 3D imaging during treatment planning, delivery, and quality control. In this context, deformable image registration can increase the accuracy of dosimetric evaluations, provided that one can account for the uncertainties associated with the registration process. To enable such capability, we propose a mathematical framework that first estimates the registration uncertainty and subsequently propagates the effects of the computed uncertainties from the registration stage through to the visualizations, organ segmentations, and dosimetric evaluations. To ensure the practicality of our proposed framework in real world image-guided radiotherapy contexts, we implemented our technique via a computationally efficient and generalizable algorithm that is compatible with existing deformable image registration software. In our clinical context of fractionated cervical cancer brachytherapy, we perform a retrospective analysis on 37 patients and present evidence that our proposed methodology for computing and propagating registration uncertainties may be beneficial during therapy planning and quality control. Specifically, we quantify and visualize the influence of registration uncertainty on dosimetric analysis during the computation of the total accumulated radiation dose on the bladder wall. We further show how registration uncertainty may be leveraged into enhanced visualizations that depict the quality of the registration and highlight potential deviations from the treatment plan prior to the delivery of radiation treatment. Finally, we show that we can improve the transfer of delineated volumetric organ segmentation labels from one fraction to the next by encoding the computed registration uncertainties into the segmentation labels.

Simultaneous 3D–2D image registration and C-arm calibration: Application to endovascular image-guided interventions

Energy Technology Data Exchange (ETDEWEB)

Mitrović, Uroš [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Cosylab, Control System Laboratory, Teslova ulica 30, Ljubljana 1000 (Slovenia); Pernuš, Franjo [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000 (Slovenia); Likar, Boštjan; Špiclin, Žiga, E-mail: ziga.spiclin@fe.uni-lj.si [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Sensum, Computer Vision Systems, Tehnološki Park 21, Ljubljana 1000 (Slovenia)

2015-11-15

Purpose: Three-dimensional to two-dimensional (3D–2D) image registration is a key to fusion and simultaneous visualization of valuable information contained in 3D pre-interventional and 2D intra-interventional images with the final goal of image guidance of a procedure. In this paper, the authors focus on 3D–2D image registration within the context of intracranial endovascular image-guided interventions (EIGIs), where the 3D and 2D images are generally acquired with the same C-arm system. The accuracy and robustness of any 3D–2D registration method, to be used in a clinical setting, is influenced by (1) the method itself, (2) uncertainty of initial pose of the 3D image from which registration starts, (3) uncertainty of C-arm’s geometry and pose, and (4) the number of 2D intra-interventional images used for registration, which is generally one and at most two. The study of these influences requires rigorous and objective validation of any 3D–2D registration method against a highly accurate reference or “gold standard” registration, performed on clinical image datasets acquired in the context of the intervention. Methods: The registration process is split into two sequential, i.e., initial and final, registration stages. The initial stage is either machine-based or template matching. The latter aims to reduce possibly large in-plane translation errors by matching a projection of the 3D vessel model and 2D image. In the final registration stage, four state-of-the-art intrinsic image-based 3D–2D registration methods, which involve simultaneous refinement of rigid-body and C-arm parameters, are evaluated. For objective validation, the authors acquired an image database of 15 patients undergoing cerebral EIGI, for which accurate gold standard registrations were established by fiducial marker coregistration. Results: Based on target registration error, the obtained success rates of 3D to a single 2D image registration after initial machine-based and

Subspace-Based Holistic Registration for Low-Resolution Facial Images

Directory of Open Access Journals (Sweden)

Boom BJ

2010-01-01

Full Text Available Subspace-based holistic registration is introduced as an alternative to landmark-based face registration, which has a poor performance on low-resolution images, as obtained in camera surveillance applications. The proposed registration method finds the alignment by maximizing the similarity score between a probe and a gallery image. We use a novel probabilistic framework for both user-independent as well as user-specific face registration. The similarity is calculated using the probability that the face image is correctly aligned in a face subspace, but additionally we take the probability into account that the face is misaligned based on the residual error in the dimensions perpendicular to the face subspace. We perform extensive experiments on the FRGCv2 database to evaluate the impact that the face registration methods have on face recognition. Subspace-based holistic registration on low-resolution images can improve face recognition in comparison with landmark-based registration on high-resolution images. The performance of the tested face recognition methods after subspace-based holistic registration on a low-resolution version of the FRGC database is similar to that after manual registration.

Complexity and accuracy of image registration methods in SPECT-guided radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Yin, L S; Duzenli, C; Moiseenko, V [Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1 (Canada); Tang, L; Hamarneh, G [Computing Science, Simon Fraser University, 9400 TASC1, Burnaby, BC, V5A 1S6 (Canada); Gill, B [Medical Physics, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Celler, A; Shcherbinin, S [Department of Radiology, University of British Columbia, 828 West 10th Ave, Vancouver, BC, V5Z 1L8 (Canada); Fua, T F; Thompson, A; Sheehan, F [Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Liu, M [Radiation Oncology, Fraser Valley Cancer Centre, BC Cancer Agency, 13750 9th Ave, Surrey, BC, V3V 1Z2 (Canada)], E-mail: lyin@bccancer.bc.ca

2010-01-07

The use of functional imaging in radiotherapy treatment (RT) planning requires accurate co-registration of functional imaging scans to CT scans. We evaluated six methods of image registration for use in SPECT-guided radiotherapy treatment planning. Methods varied in complexity from 3D affine transform based on control points to diffeomorphic demons and level set non-rigid registration. Ten lung cancer patients underwent perfusion SPECT-scans prior to their radiotherapy. CT images from a hybrid SPECT/CT scanner were registered to a planning CT, and then the same transformation was applied to the SPECT images. According to registration evaluation measures computed based on the intensity difference between the registered CT images or based on target registration error, non-rigid registrations provided a higher degree of accuracy than rigid methods. However, due to the irregularities in some of the obtained deformation fields, warping the SPECT using these fields may result in unacceptable changes to the SPECT intensity distribution that would preclude use in RT planning. Moreover, the differences between intensity histograms in the original and registered SPECT image sets were the largest for diffeomorphic demons and level set methods. In conclusion, the use of intensity-based validation measures alone is not sufficient for SPECT/CT registration for RTTP. It was also found that the proper evaluation of image registration requires the use of several accuracy metrics.

Registration Service

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GS Department

2010-01-01

Following a reorganization in Building 55, please note that the Registration Service is now organised as follows :  Ground floor: access cards (76903). 1st floor : registration of external firms’ personnel (76611 / 76622); car access stickers (76633); biometric registration (79710). Opening hours: 07-30 to 16-00 non-stop. GS-SEM Group General Infrastructure Services Department

Groupwise registration of MR brain images with tumors

Science.gov (United States)

Tang, Zhenyu; Wu, Yihong; Fan, Yong

2017-09-01

A novel groupwise image registration framework is developed for registering MR brain images with tumors. Our method iteratively estimates a normal-appearance counterpart for each tumor image to be registered and constructs a directed graph (digraph) of normal-appearance images to guide the groupwise image registration. Particularly, our method maps each tumor image to its normal appearance counterpart by identifying and inpainting brain tumor regions with intensity information estimated using a low-rank plus sparse matrix decomposition based image representation technique. The estimated normal-appearance images are groupwisely registered to a group center image guided by a digraph of images so that the total length of ‘image registration paths’ to be the minimum, and then the original tumor images are warped to the group center image using the resulting deformation fields. We have evaluated our method based on both simulated and real MR brain tumor images. The registration results were evaluated with overlap measures of corresponding brain regions and average entropy of image intensity information, and Wilcoxon signed rank tests were adopted to compare different methods with respect to their regional overlap measures. Compared with a groupwise image registration method that is applied to normal-appearance images estimated using the traditional low-rank plus sparse matrix decomposition based image inpainting, our method achieved higher image registration accuracy with statistical significance (p  =  7.02  ×  10-9).

76 FR 57060 - International Cooperation on Harmonisation of Technical Requirements for Registration of...

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2011-09-15

...] International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal... veterinary use by the International Cooperation on Harmonisation of Technical Requirements for Registration... regulatory authorities and industry associations to promote the international harmonization of regulatory...

Deformable image registration using convolutional neural networks

Science.gov (United States)

Eppenhof, Koen A. J.; Lafarge, Maxime W.; Moeskops, Pim; Veta, Mitko; Pluim, Josien P. W.

2018-03-01

Deformable image registration can be time-consuming and often needs extensive parameterization to perform well on a specific application. We present a step towards a registration framework based on a three-dimensional convolutional neural network. The network directly learns transformations between pairs of three-dimensional images. The outputs of the network are three maps for the x, y, and z components of a thin plate spline transformation grid. The network is trained on synthetic random transformations, which are applied to a small set of representative images for the desired application. Training therefore does not require manually annotated ground truth deformation information. The methodology is demonstrated on public data sets of inspiration-expiration lung CT image pairs, which come with annotated corresponding landmarks for evaluation of the registration accuracy. Advantages of this methodology are its fast registration times and its minimal parameterization.

76 FR 57057 - International Cooperation on Harmonisation of Technical Requirements for Registration of...

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2011-09-15

...] International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal... veterinary use by the International Cooperation on Harmonisation of Technical Requirements for Registration... undertaken by regulatory authorities and industry associations to promote the international harmonization of...

Clinical leadership and pre-registration nursing programmes: A model for clinical leadership and a prospective curriculum implementation and evaluation research strategy.

Science.gov (United States)

Brown, Angela; Dewing, Jan; Crookes, Patrick

2016-07-01

To present for wider debate a conceptual model for clinical leadership development in pre-registration nursing programmes and a proposed implementation plan. Globally, leadership in nursing has become a significant issue. Whilst there is continued support for leadership preparation in pre-registration nursing programmes, there have been very few published accounts of curriculum content and/or pedagogical approaches that foster clinical leadership development in pre-registration nursing. A doctoral research study has resulted in the creation of an overarching model for clinical leadership. A multi-method research study using theoretical and empirical literature 1974-2015, a focus group, expert opinion and a national on-line survey. A conceptual model of clinical leadership development in pre-registration nursing programme is presented, including the infinity loop of clinical leadership, an integral curriculum thread and a conceptual model: a curriculum-pedagogy nexus for clinical leadership. In order to test out usability and evaluate effectiveness, a multi method programme of research in one school of nursing in Australia is outlined. Implementation of the proposed conceptual model for clinical leadership development in pre-registration nursing programmes and a programme of (post-doctoral) research will contribute to what is known about curriculum content and pedagogy for nurse academics. Importantly, for nursing students and the profession as a whole, there is a clearer expectation of what clinical leadership might look like in the novice registered nurse. For nurse academics a model is offered for consideration in curriculum design and implementation with an evaluation strategy that could be replicated. Copyright © 2016 Elsevier Ltd. All rights reserved.

78 FR 8522 - Chlorpyrifos Registration Review; Preliminary Evaluation of the Potential Risk From...

Science.gov (United States)

2013-02-06

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2008-0850; FRL-9376-5] Chlorpyrifos Registration... preliminary volatilization assessment for the registration review of chlorpyrifos and opens a public comment... assessment for chlorpyrifos uses. After reviewing comments received during the public comment period, EPA...

2D-3D rigid registration to compensate for prostate motion during 3D TRUS-guided biopsy.

Science.gov (United States)

De Silva, Tharindu; Fenster, Aaron; Cool, Derek W; Gardi, Lori; Romagnoli, Cesare; Samarabandu, Jagath; Ward, Aaron D

2013-02-01

Three-dimensional (3D) transrectal ultrasound (TRUS)-guided systems have been developed to improve targeting accuracy during prostate biopsy. However, prostate motion during the procedure is a potential source of error that can cause target misalignments. The authors present an image-based registration technique to compensate for prostate motion by registering the live two-dimensional (2D) TRUS images acquired during the biopsy procedure to a preacquired 3D TRUS image. The registration must be performed both accurately and quickly in order to be useful during the clinical procedure. The authors implemented an intensity-based 2D-3D rigid registration algorithm optimizing the normalized cross-correlation (NCC) metric using Powell's method. The 2D TRUS images acquired during the procedure prior to biopsy gun firing were registered to the baseline 3D TRUS image acquired at the beginning of the procedure. The accuracy was measured by calculating the target registration error (TRE) using manually identified fiducials within the prostate; these fiducials were used for validation only and were not provided as inputs to the registration algorithm. They also evaluated the accuracy when the registrations were performed continuously throughout the biopsy by acquiring and registering live 2D TRUS images every second. This measured the improvement in accuracy resulting from performing the registration, continuously compensating for motion during the procedure. To further validate the method using a more challenging data set, registrations were performed using 3D TRUS images acquired by intentionally exerting different levels of ultrasound probe pressures in order to measure the performance of our algorithm when the prostate tissue was intentionally deformed. In this data set, biopsy scenarios were simulated by extracting 2D frames from the 3D TRUS images and registering them to the baseline 3D image. A graphics processing unit (GPU)-based implementation was used to improve the

The Insight ToolKit Image Registration Framework

Directory of Open Access Journals (Sweden)

Brian eAvants

2014-04-01

Full Text Available Publicly available scientific resources help establish evaluation standards, provide a platform for teaching and improve reproducibility. Version 4 of the Insight ToolKit ( ITK4 seeks to es- tablish new standards in publicly available image registration methodology. ITK4 makes severaladvances in comparison to previous versions of ITK. ITK4 supports both multivariate images and objective functions; it also unifies high-dimensional (deformation field and low-dimensional (affine transformations with metrics that are reusable across transform types and with com- posite transforms that allow arbitrary series of geometric mappings to be chained together seamlessly. Metrics and optimizers take advantage of multi-core resources, when available.Furthermore, ITK4 reduces the parameter optimization burden via principled heuristics that automatically set scaling across disparate parameter types (rotations versus translations. A related approach also constrains steps sizes for gradient-based optimizers. The result is that tuning for different metrics and/or image pairs is rarely necessary allowing the researcher tomore easily focus on design/comparison of registration strategies. In total, the ITK4 contribu- tion is intended as a structure to support reproducible research practices, will provide a more extensive foundation against which to evaluate new work in image registration and also enable application level programmers a broad suite of tools on which to build. Finally, we contextu- alize this work with a reference registration evaluation study with application to pediatric brainlabeling.

Preliminary design of the database and registration system for the national malignant tumor interventional therapy

International Nuclear Information System (INIS)

Hu Di; Zeng Jinjin; Wang Jianfeng; Zhai Renyou

2010-01-01

Objective: This research is one of the sub-researches of 'The comparative study of the standards of interventional therapies and the evaluation of the long-term and middle-term effects for common malignant tumors', which is one of the National Key Technologies R and D Program in the eleventh five-year plan. Based on the project,the authors need to establish an international standard in order to set up the national tumor interventional therapy database and registration system. Methods: By using the computing programs of downloading software, self-management and automatic integration, the program was written by the JAVA words. Results: The database and registration system for the national tumor interventional therapy was successfully set up, and it could complete both the simple and complex inquiries. The software worked well through the initial debugging. Conclusion: The national tumor interventional therapy database and registration system can not only precisely tell the popularizing rate of the interventional therapy nationwide, compare the results of different methods, provide the latest news concerning the interventional therapy, subsequently promote the academic exchanges between hospitals, but also help us get the information about the distribution of the interventional physicians, the consuming quantity and variety of the interventional materials, so the medical costs can be reduced. (authors)

Deformable Registration for Longitudinal Breast MRI Screening.

Science.gov (United States)

Mehrabian, Hatef; Richmond, Lara; Lu, Yingli; Martel, Anne L

2018-04-13

MRI screening of high-risk patients for breast cancer provides very high sensitivity, but with a high recall rate and negative biopsies. Comparing the current exam to prior exams reduces the number of follow-up procedures requested by radiologists. Such comparison, however, can be challenging due to the highly deformable nature of breast tissues. Automated co-registration of multiple scans has the potential to aid diagnosis by providing 3D images for side-by-side comparison and also for use in CAD systems. Although many deformable registration techniques exist, they generally have a large number of parameters that need to be optimized and validated for each new application. Here, we propose a framework for such optimization and also identify the optimal input parameter set for registration of 3D T 1 -weighted MRI of breast using Elastix, a widely used and freely available registration tool. A numerical simulation study was first conducted to model the breast tissue and its deformation through finite element (FE) modeling. This model generated the ground truth for evaluating the registration accuracy by providing the deformation of each voxel in the breast volume. An exhaustive search was performed over various values of 7 registration parameters (4050 different combinations of parameters were assessed) and the optimum parameter set was determined. This study showed that there was a large variation in the registration accuracy of different parameter sets ranging from 0.29 mm to 2.50 mm in median registration error and 3.71 mm to 8.90 mm in 95 percentile of the registration error. Mean registration errors of 0.32 mm, 0.29 mm, and 0.30 mm and 95 percentile errors of 3.71 mm, 5.02 mm, and 4.70 mm were obtained by the three best parameter sets. The optimal parameter set was applied to consecutive breast MRI scans of 13 patients. A radiologist identified 113 landmark pairs (~ 11 per patient) which were used to assess registration accuracy. The results demonstrated that

Accelerating Neuroimage Registration through Parallel Computation of Similarity Metric.

Directory of Open Access Journals (Sweden)

Yun-Gang Luo

Full Text Available Neuroimage registration is crucial for brain morphometric analysis and treatment efficacy evaluation. However, existing advanced registration algorithms such as FLIRT and ANTs are not efficient enough for clinical use. In this paper, a GPU implementation of FLIRT with the correlation ratio (CR as the similarity metric and a GPU accelerated correlation coefficient (CC calculation for the symmetric diffeomorphic registration of ANTs have been developed. The comparison with their corresponding original tools shows that our accelerated algorithms can greatly outperform the original algorithm in terms of computational efficiency. This paper demonstrates the great potential of applying these registration tools in clinical applications.

21 CFR 710.6 - Notification of registrant; cosmetic product establishment registration number.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Notification of registrant; cosmetic product... OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS VOLUNTARY REGISTRATION OF COSMETIC PRODUCT ESTABLISHMENTS § 710.6 Notification of registrant; cosmetic product establishment registration number. The...

A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive

International Nuclear Information System (INIS)

Castillo, Richard; Castillo, Edward; Wood, Abbie M; Ludwig, Michelle S; Guerrero, Thomas; Fuentes, David; Ahmad, Moiz

2013-01-01

Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts. (paper)

Spatially weighted mutual information image registration for image guided radiation therapy

International Nuclear Information System (INIS)

Park, Samuel B.; Rhee, Frank C.; Monroe, James I.; Sohn, Jason W.

2010-01-01

Purpose: To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application for image guided radiation therapy (IGRT). Methods: It is well known that rigid-body image registration with mutual information is dependent on the size and location of the image subset on which the alignment analysis is based [the designated region of interest (ROI)]. Therefore, careful review and manual adjustments of the resulting registration are frequently necessary. Although there were some investigations of weighted mutual information (WMI), these efforts could not apply the differential importance to a particular spatial location since WMI only applies the weight to the joint histogram space. The authors developed the spatially weighted mutual information (SWMI) metric by incorporating an adaptable weight function with spatial localization into mutual information. SWMI enables the user to apply the selected transform to medically ''important'' areas such as tumors and critical structures, so SWMI is neither dominated by, nor neglects the neighboring structures. Since SWMI can be utilized with any weight function form, the authors presented two examples of weight functions for IGRT application: A Gaussian-shaped weight function (GW) applied to a user-defined location and a structures-of-interest (SOI) based weight function. An image registration example using a synthesized 2D image is presented to illustrate the efficacy of SWMI. The convergence and feasibility of the registration method as applied to clinical imaging is illustrated by fusing a prostate treatment planning CT with a clinical cone beam CT (CBCT) image set acquired for patient alignment. Forty-one trials are run to test the speed of convergence. The authors also applied SWMI registration using two types of weight functions to two head and neck cases and a prostate case with clinically acquired CBCT/MVCT image sets. The

Spatially weighted mutual information image registration for image guided radiation therapy.

Science.gov (United States)

Park, Samuel B; Rhee, Frank C; Monroe, James I; Sohn, Jason W

2010-09-01

To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application for image guided radiation therapy (IGRT). It is well known that rigid-body image registration with mutual information is dependent on the size and location of the image subset on which the alignment analysis is based [the designated region of interest (ROI)]. Therefore, careful review and manual adjustments of the resulting registration are frequently necessary. Although there were some investigations of weighted mutual information (WMI), these efforts could not apply the differential importance to a particular spatial location since WMI only applies the weight to the joint histogram space. The authors developed the spatially weighted mutual information (SWMI) metric by incorporating an adaptable weight function with spatial localization into mutual information. SWMI enables the user to apply the selected transform to medically "important" areas such as tumors and critical structures, so SWMI is neither dominated by, nor neglects the neighboring structures. Since SWMI can be utilized with any weight function form, the authors presented two examples of weight functions for IGRT application: A Gaussian-shaped weight function (GW) applied to a user-defined location and a structures-of-interest (SOI) based weight function. An image registration example using a synthesized 2D image is presented to illustrate the efficacy of SWMI. The convergence and feasibility of the registration method as applied to clinical imaging is illustrated by fusing a prostate treatment planning CT with a clinical cone beam CT (CBCT) image set acquired for patient alignment. Forty-one trials are run to test the speed of convergence. The authors also applied SWMI registration using two types of weight functions to two head and neck cases and a prostate case with clinically acquired CBCT/ MVCT image sets. The SWMI registration with

Performance Evaluation of State-of-the-Art Local Feature Detectors and Descriptors in the Context of Longitudinal Registration of Retinal Images.

Science.gov (United States)

Saha, Sajib K; Xiao, Di; Frost, Shaun; Kanagasingam, Yogesan

2018-02-17

In this paper we systematically evaluate the performance of several state-of-the-art local feature detectors and descriptors in the context of longitudinal registration of retinal images. Longitudinal (temporal) registration facilitates to track the changes in the retina that has happened over time. A wide number of local feature detectors and descriptors exist and many of them have already applied for retinal image registration, however, no comparative evaluation has been made so far to analyse their respective performance. In this manuscript we evaluate the performance of the widely known and commonly used detectors such as Harris, SIFT, SURF, BRISK, and bifurcation and cross-over points. As of descriptors SIFT, SURF, ALOHA, BRIEF, BRISK and PIIFD are used. Longitudinal retinal image datasets containing a total of 244 images are used for the experiment. The evaluation reveals some potential findings including more robustness of SURF and SIFT keypoints than the commonly used bifurcation and cross-over points, when detected on the vessels. SIFT keypoints can be detected with a reliability of 59% for without pathology images and 45% for with pathology images. For SURF keypoints these values are respectively 58% and 47%. ALOHA descriptor is best suited to describe SURF keypoints, which ensures an overall matching accuracy, distinguishability of 83%, 93% and 78%, 83% for without pathology and with pathology images respectively.

16 CFR 1130.8 - Requirements for Web site registration or alternative e-mail registration.

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2010-01-01

... registration. (a) Link to registration page. The manufacturer's Web site, or other Web site established for the... web page that goes directly to “Product Registration.” (b) Purpose statement. The registration page... registration page. The Web site registration page shall request only the consumer's name, address, telephone...

Automated registration of multispectral MR vessel wall images of the carotid artery

Energy Technology Data Exchange (ETDEWEB)

Klooster, R. van ' t; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der, E-mail: rvdgeest@lumc.nl [Department of Radiology, Division of Image Processing, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Klein, S. [Department of Radiology and Department of Medical Informatics, Biomedical Imaging Group Rotterdam, Erasmus MC, Rotterdam 3015 GE (Netherlands); Kwee, R. M.; Kooi, M. E. [Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht 6202 AZ (Netherlands)

2013-12-15

Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

Automated registration of multispectral MR vessel wall images of the carotid artery

International Nuclear Information System (INIS)

Klooster, R. van 't; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der; Klein, S.; Kwee, R. M.; Kooi, M. E.

2013-01-01

Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

Co-registration of the BNCT treatment planning images for clinical practice

International Nuclear Information System (INIS)

Salli, Eero; Seppaelae, Tiina; Kankaanranta, Leena; Asikainen, Sami; Savolainen, Sauli; Koivunoro, Hanna

2006-01-01

We have co-registered MRI, CT and FBPA-PET images for BNCT in clinical practice. Co-registration improves the spatial accuracy of the treatment planning by enabling use of information from all the co-registered modalities. The multimodal co-registration has been implemented as a service product provided by the Imaging Center of Helsinki University Central Hospital to other departments. To increase the accuracy of co-registration and patient positioning in the head area BNCT, a patient-specific fixation mask suitable for PET, MRI and CT was developed. The goal of the fixation mask is to normalize the orientation of the patient's head and neck. Co-registration is performed at the image processing unit by using a rigid body model, mutual-information based algorithms and partly in-house developed software tools. The accuracy of co-registration is verified by comparing the locations of the external skin markers and anatomical landmarks in different modalities. After co-registration, the images are transformed and covered into a format required by the BNCT dose-planning software and set to the dose-planning unit of the hospital. So far co-registration has been done for 22 patients. The co-registration protocol has proved to be reliable and efficient. Some registration errors are seen on some patients in the neck area because the rigid-body model used in co-registration is not fully valid for the brain-neck entity. The registration accuracy in this area could likely be improved by implementing a co-registration procedure utilizing a partly non-rigid body model. (author)

Constrained non-rigid registration for whole body image registration: method and validation

Science.gov (United States)

Li, Xia; Yankeelov, Thomas E.; Peterson, Todd E.; Gore, John C.; Dawant, Benoit M.

2007-03-01

3D intra- and inter-subject registration of image volumes is important for tasks that include measurements and quantification of temporal/longitudinal changes, atlas-based segmentation, deriving population averages, or voxel and tensor-based morphometry. A number of methods have been proposed to tackle this problem but few of them have focused on the problem of registering whole body image volumes acquired either from humans or small animals. These image volumes typically contain a large number of articulated structures, which makes registration more difficult than the registration of head images, to which the vast majority of registration algorithms have been applied. To solve this problem, we have previously proposed an approach, which initializes an intensity-based non-rigid registration algorithm with a point based registration technique [1, 2]. In this paper, we introduce new constraints into our non-rigid registration algorithm to prevent the bones from being deformed inaccurately. Results we have obtained show that the new constrained algorithm leads to better registration results than the previous one.

Registration of Space Objects

Science.gov (United States)

Schmidt-Tedd, Bernhard

2017-07-01

Space objects are subject to registration in order to allocate "jurisdiction and control" over those objects in the sovereign-free environment of outer space. This approach is similar to the registration of ships in view of the high sea and for aircrafts with respect to the international airspace. Registration is one of the basic principles of space law, starting with UN General Assembly Resolution 1721 B (XVI) of December 20, 1961, followed by Resolution 1962 (XVIII) of December 13, 1963, then formulated in Article VIII of the Outer Space Treaty of 1967 and as specified in the Registration Convention of 1975. Registration of space objects can be seen today as a principle of customary international law, relevant for each spacefaring state. Registration is divided into a national and an international level. The State Party establishes a national registry for its space objects, and those registrations have to be communicated via diplomatic channel to the UN Register of space objects. This UN Register is handled by the UN Office for Outer Space Affairs (UNOOSA) and is an open source of information for space objects worldwide. Registration is linked to the so-called launching state of the relevant space object. There might be more than one launching state for the specific launch event, but only one state actor can register a specific space object. The state of registry gains "jurisdiction and control" over the space object and therefore no double registration is permissible. Based on the established UN Space Law, registration practice was subject to some adaptions due to technical developments and legal challenges. After the privatization of the major international satellite organizations, a number of non-registrations had to be faced. The state actors reacted with the UN Registration Practice Resolution of 2007 as elaborated in the Legal Subcommittee of UNCOPUOS, the Committee for the Peaceful Use of Outer Space. In this context an UNOOSA Registration Information

21 CFR 1301.36 - Suspension or revocation of registration; suspension of registration pending final order...

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Suspension or revocation of registration; suspension of registration pending final order; extension of registration pending final order. 1301.36... registration pending final order; extension of registration pending final order. (a) For any registration...

21 CFR 710.8 - Misbranding by reference to registration or to registration number.

Science.gov (United States)

2010-04-01

... HUMAN SERVICES (CONTINUED) COSMETICS VOLUNTARY REGISTRATION OF COSMETIC PRODUCT ESTABLISHMENTS § 710.8 Misbranding by reference to registration or to registration number. Registration of a cosmetic product... products by the Food and Drug Administration. Any representation in labeling or advertising that creates an...

A multicore based parallel image registration method.

Science.gov (United States)

Yang, Lin; Gong, Leiguang; Zhang, Hong; Nosher, John L; Foran, David J

2009-01-01

Image registration is a crucial step for many image-assisted clinical applications such as surgery planning and treatment evaluation. In this paper we proposed a landmark based nonlinear image registration algorithm for matching 2D image pairs. The algorithm was shown to be effective and robust under conditions of large deformations. In landmark based registration, the most important step is establishing the correspondence among the selected landmark points. This usually requires an extensive search which is often computationally expensive. We introduced a nonregular data partition algorithm using the K-means clustering algorithm to group the landmarks based on the number of available processing cores. The step optimizes the memory usage and data transfer. We have tested our method using IBM Cell Broadband Engine (Cell/B.E.) platform.

Laser interrogation of latent vehicle registration number

Energy Technology Data Exchange (ETDEWEB)

Russo, R.E. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.]|[Lawrence Livermore National Lab., CA (United States). Forensic Science Center; Pelkey, G.E. [City of Livermore Police Dept., CA (United States); Grant, P.; Whipple, R.E.; Andresen, B.D. [Lawrence Livermore National Lab., CA (United States). Forensic Science Center

1994-09-01

A recent investigation involved automobile registration numbers as important evidentiary specimens. In California, as in most states, small, thin metallic decals are issued to owners of vehicles each year as the registration is renewed. The decals are applied directly to the license plate of the vehicle and typically on top of the previous year`s expired decal. To afford some degree of security, the individual registration decals have been designed to tear easily; they cannot be separated from each other, but can be carefully removed intact from the metal license plate by using a razor blade. In September 1993, the City of Livermore Police Department obtained a blue 1993 California decal that had been placed over an orange 1992 decal. The two decals were being investigated as possible evidence in a case involving vehicle registration fraud. To confirm the suspicion and implicate a suspect, the department needed to known the registration number on the bottom (completely covered) 1992 decal. The authors attempted to use intense and directed light to interrogate the colored stickers. Optical illumination using a filtered white-light source partially identified the latent number. However, the most successful technique used a tunable dye laser pumped by a pulsed Nd:YAG laser. By selectively tuning the wavelength and intensity of the dye laser, backlit illumination of the decals permitted visualization of the underlying registration number through the surface of the top sticker. With optimally-tuned wavelength and intensity, 100% accuracy was obtained in identifying the sequence of latent characters. The advantage of optical techniques is their completely nondestructive nature, thus preserving the evidence for further interrogation or courtroom presentation.

A prospective comparison between auto-registration and manual registration of real-time ultrasound with MR images for percutaneous ablation or biopsy of hepatic lesions.

Science.gov (United States)

Cha, Dong Ik; Lee, Min Woo; Song, Kyoung Doo; Oh, Young-Taek; Jeong, Ja-Yeon; Chang, Jung-Woo; Ryu, Jiwon; Lee, Kyong Joon; Kim, Jaeil; Bang, Won-Chul; Shin, Dong Kuk; Choi, Sung Jin; Koh, Dalkwon; Seo, Bong Koo; Kim, Kyunga

2017-06-01

To compare the accuracy and required time for image fusion of real-time ultrasound (US) with pre-procedural magnetic resonance (MR) images between positioning auto-registration and manual registration for percutaneous radiofrequency ablation or biopsy of hepatic lesions. This prospective study was approved by the institutional review board, and all patients gave written informed consent. Twenty-two patients (male/female, n = 18/n = 4; age, 61.0 ± 7.7 years) who were referred for planning US to assess the feasibility of radiofrequency ablation (n = 21) or biopsy (n = 1) for focal hepatic lesions were included. One experienced radiologist performed the two types of image fusion methods in each patient. The performance of auto-registration and manual registration was evaluated. The accuracy of the two methods, based on measuring registration error, and the time required for image fusion for both methods were recorded using in-house software and respectively compared using the Wilcoxon signed rank test. Image fusion was successful in all patients. The registration error was not significantly different between the two methods (auto-registration: median, 3.75 mm; range, 1.0-15.8 mm vs. manual registration: median, 2.95 mm; range, 1.2-12.5 mm, p = 0.242). The time required for image fusion was significantly shorter with auto-registration than with manual registration (median, 28.5 s; range, 18-47 s, vs. median, 36.5 s; range, 14-105 s, p = 0.026). Positioning auto-registration showed promising results compared with manual registration, with similar accuracy and even shorter registration time.

Pre-processing, registration and selection of adaptive optics corrected retinal images.

Science.gov (United States)

Ramaswamy, Gomathy; Devaney, Nicholas

2013-07-01

In this paper, the aim is to demonstrate enhanced processing of sequences of fundus images obtained using a commercial AO flood illumination system. The purpose of the work is to (1) correct for uneven illumination at the retina (2) automatically select the best quality images and (3) precisely register the best images. Adaptive optics corrected retinal images are pre-processed to correct uneven illumination using different methods; subtracting or dividing by the average filtered image, homomorphic filtering and a wavelet based approach. These images are evaluated to measure the image quality using various parameters, including sharpness, variance, power spectrum kurtosis and contrast. We have carried out the registration in two stages; a coarse stage using cross-correlation followed by fine registration using two approaches; parabolic interpolation on the peak of the cross-correlation and maximum-likelihood estimation. The angle of rotation of the images is measured using a combination of peak tracking and Procrustes transformation. We have found that a wavelet approach (Daubechies 4 wavelet at 6th level decomposition) provides good illumination correction with clear improvement in image sharpness and contrast. The assessment of image quality using a 'Designer metric' works well when compared to visual evaluation, although it is highly correlated with other metrics. In image registration, sub-pixel translation measured using parabolic interpolation on the peak of the cross-correlation function and maximum-likelihood estimation are found to give very similar results (RMS difference 0.047 pixels). We have confirmed that correcting rotation of the images provides a significant improvement, especially at the edges of the image. We observed that selecting the better quality frames (e.g. best 75% images) for image registration gives improved resolution, at the expense of poorer signal-to-noise. The sharpness map of the registered and de-rotated images shows increased

Registration methods for pulmonary image analysis integration of morphological and physiological knowledge

CERN Document Server

Schmidt-Richberg, Alexander

2014-01-01

Various applications in the field of pulmonary image analysis require a registration of CT images of the lung. For example, a registration-based estimation of the breathing motion is employed to increase the accuracy of dose distribution in radiotherapy. Alexander Schmidt-Richberg develops methods to explicitly model morphological and physiological knowledge about respiration in algorithms for the registration of thoracic CT images. The author focusses on two lung-specific issues: on the one hand, the alignment of the interlobular fissures and on the other hand, the estimation of sliding motion at the lung boundaries. He shows that by explicitly considering these aspects based on a segmentation of the respective structure, registration accuracy can be significantly improved.

Comparison of time-series registration methods in breast dynamic infrared imaging

Science.gov (United States)

Riyahi-Alam, S.; Agostini, V.; Molinari, F.; Knaflitz, M.

2015-03-01

Automated motion reduction in dynamic infrared imaging is on demand in clinical applications, since movement disarranges time-temperature series of each pixel, thus originating thermal artifacts that might bias the clinical decision. All previously proposed registration methods are feature based algorithms requiring manual intervention. The aim of this work is to optimize the registration strategy specifically for Breast Dynamic Infrared Imaging and to make it user-independent. We implemented and evaluated 3 different 3D time-series registration methods: 1. Linear affine, 2. Non-linear Bspline, 3. Demons applied to 12 datasets of healthy breast thermal images. The results are evaluated through normalized mutual information with average values of 0.70 ±0.03, 0.74 ±0.03 and 0.81 ±0.09 (out of 1) for Affine, Bspline and Demons registration, respectively, as well as breast boundary overlap and Jacobian determinant of the deformation field. The statistical analysis of the results showed that symmetric diffeomorphic Demons' registration method outperforms also with the best breast alignment and non-negative Jacobian values which guarantee image similarity and anatomical consistency of the transformation, due to homologous forces enforcing the pixel geometric disparities to be shortened on all the frames. We propose Demons' registration as an effective technique for time-series dynamic infrared registration, to stabilize the local temperature oscillation.

Gaussian Process Interpolation for Uncertainty Estimation in Image Registration

Science.gov (United States)

Wachinger, Christian; Golland, Polina; Reuter, Martin; Wells, William

2014-01-01

Intensity-based image registration requires resampling images on a common grid to evaluate the similarity function. The uncertainty of interpolation varies across the image, depending on the location of resampled points relative to the base grid. We propose to perform Bayesian inference with Gaussian processes, where the covariance matrix of the Gaussian process posterior distribution estimates the uncertainty in interpolation. The Gaussian process replaces a single image with a distribution over images that we integrate into a generative model for registration. Marginalization over resampled images leads to a new similarity measure that includes the uncertainty of the interpolation. We demonstrate that our approach increases the registration accuracy and propose an efficient approximation scheme that enables seamless integration with existing registration methods. PMID:25333127

Automatic intra-modality brain image registration method

International Nuclear Information System (INIS)

Whitaker, J.M.; Ardekani, B.A.; Braun, M.

1996-01-01

Full text: Registration of 3D images of brain of the same or different subjects has potential importance in clinical diagnosis, treatment planning and neurological research. The broad aim of our work is to produce an automatic and robust intra-modality, brain image registration algorithm for intra-subject and inter-subject studies. Our algorithm is composed of two stages. Initial alignment is achieved by finding the values of nine transformation parameters (representing translation, rotation and scale) that minimise the nonoverlapping regions of the head. This is achieved by minimisation of the sum of the exclusive OR of two binary head images, produced using the head extraction procedure described by Ardekani et al. (J Comput Assist Tomogr, 19:613-623, 1995). The initial alignment successfully determines the scale parameters and gross translation and rotation parameters. Fine alignment uses an objective function described for inter-modality registration in Ardekani et al. (ibid.). The algorithm segments one of the images to be aligned into a set of connected components using K-means clustering. Registration is achieved by minimising the K-means variance of the segmentation induced in the other image. Similarity of images of the same modality makes the method attractive for intra-modality registration. A 3D MR image, with voxel dimensions, 2x2x6 mm, was misaligned. The registered image shows visually accurate registration. The average displacement of a pixel from its correct location was measured to be 3.3 mm. The algorithm was tested on intra-subject MR images and was found to produce good qualitative results. Using the data available, the algorithm produced promising qualitative results in intra-subject registration. Further work is necessary in its application to intersubject registration, due to large variability in brain structure between subjects. Clinical evaluation of the algorithm for selected applications is required

Characterization of Foliage Mutants for Plant Variety Registration

International Nuclear Information System (INIS)

Affrida Abu Hassan; Shuhaimi Shamsuddin; Zaiton Ahmad

2011-01-01

Breeding for new plant varieties requires a substantial investment in terms of skill, labour, material resources and financing. Thus, registration of new plant variety is important to ensure return of revenue and protection of the breeder's right. Before a new variety is registered, it has to comply certain requirements under Plant Variety Protection Act. One of the most important requirements is, the new species/variety must be morphologically distinguishable from existing plant varieties. This paper discusses detailed leaf characteristics of 4 foliage mutants produced by Malaysian Nuclear Agency as part of the requirement for new variety registration. (author)

Personal protective equipment for registration purposes of pesticides

NARCIS (Netherlands)

Gerritsen-Ebben, M.G.; Brouwer, D.H.; Hemmen, J.J. van

2007-01-01

Regulatory authorities in North America, Europe and Australia use different approaches for the estimation of exposure reduction effectiveness of personal protective equipment (PPE) in registration processes of agrochemical pesticides. TNO has investigated current views and facts for the use of

Process Evaluation of a School-Based Education Program about Organ Donation and Registration, and the Intention for Continuance

Science.gov (United States)

Reubsaet, A.; Reinaerts, E. B. M.; Brug, J.; van Hooff, J. P.; van den Borne, H. W.

2004-01-01

This paper describes the process evaluation of an organ donation education program for high school students aged 15-18 years of which the effectiveness was established. The program consisted of three components: a video with group discussion, an interactive computer-tailored program and a registration training session. A cross-sectional survey was…

32 CFR 1615.1 - Registration.

Science.gov (United States)

2010-07-01

... registration card or other method of registration prescribed by the Director of Selective Service by a person... the records (master computer file) of the Selective Service System. Registration is completed when... Director include completing a Selective Service Registration Card at a classified Post Office, registration...

The use of Landsat-4 MSS digital data in temporal data sets and the evaluation of scene-to-scene registration accuracy

Science.gov (United States)

Anderson, J. E.

1985-01-01

The MSS sensor on Landsat 4 is, in certain performance aspects, diferent from those of Landsats 1 through 3. These differences created some concern in the NASA research community as to whether individual data sets can be registered accurately enough to produce acceptable data sets for multitemporal data analysis. The use of Landsat 4 MSS digital data in temporal data sets is examined and a method is presented for estimating temporal registration accuracy based on the use of an X-Y digitizer and grey tone electrostatic plots. Results indicate that the RMS temporal registration errors are not significantly different from the temporal data sets generated using Landsat 4 and Landsat 2 data (33.35 meters) and the temporal data set constructed from two Landsat 2 data sets (33.61 meters). A derivation of the model used to evaluate the temporal registration is included.

Registration of 3-dimensional facial photographs for clinical use.

Science.gov (United States)

Maal, Thomas J J; van Loon, Bram; Plooij, Joanneke M; Rangel, Frits; Ettema, Anke M; Borstlap, Wilfred A; Bergé, Stefaan J

2010-10-01

To objectively evaluate treatment outcomes in oral and maxillofacial surgery, pre- and post-treatment 3-dimensional (3D) photographs of the patient's face can be registered. For clinical use, it is of great importance that this registration process is accurate (photographs were captured at 3 different times: baseline (T(0)), after 1 minute (T(1)), and 3 weeks later (T(2)). Furthermore, a 3D photograph of the volunteer laughing (T(L)) was acquired to investigate the effect of facial expression. Two different registration methods were used to register the photographs acquired at all different times: surface-based registration and reference-based registration. Within the surface-based registration, 2 different software packages (Maxilim [Medicim NV, Mechelen, Belgium] and 3dMD Patient [3dMD LLC, Atlanta, GA]) were used to register the 3D photographs acquired at the various times. The surface-based registration process was repeated with the preprocessed photographs. Reference-based registration (Maxilim) was performed twice by 2 observers investigating the inter- and intraobserver error. The mean registration errors are small for the 3D photographs at rest (0.39 mm for T(0)-T(1) and 0.52 mm for T(0)-T(2)). The mean registration error increased to 1.2 mm for the registration between the 3D photographs acquired at T(0) and T(L). The mean registration error for the reference-based method was 1.0 mm for T(0)-T(1), 1.1 mm for T(0)-T(2), and 1.5 mm for T(0) and T(L). The mean registration errors for the preprocessed photographs were even smaller (0.30 mm for T(0)-T(1), 0.42 mm for T(0)-T(2), and 1.2 mm for T(0) and T(L)). Furthermore, a strong correlation between the results of both software packages used for surface-based registration was found. The intra- and interobserver error for the reference-based registration method was found to be 1.2 and 1.0 mm, respectively. Surface-based registration is an accurate method to compare 3D photographs of the same individual at

Registration performance on EUV masks using high-resolution registration metrology

Science.gov (United States)

Steinert, Steffen; Solowan, Hans-Michael; Park, Jinback; Han, Hakseung; Beyer, Dirk; Scherübl, Thomas

2016-10-01

Next-generation lithography based on EUV continues to move forward to high-volume manufacturing. Given the technical challenges and the throughput concerns a hybrid approach with 193 nm immersion lithography is expected, at least in the initial state. Due to the increasing complexity at smaller nodes a multitude of different masks, both DUV (193 nm) and EUV (13.5 nm) reticles, will then be required in the lithography process-flow. The individual registration of each mask and the resulting overlay error are of crucial importance in order to ensure proper functionality of the chips. While registration and overlay metrology on DUV masks has been the standard for decades, this has yet to be demonstrated on EUV masks. Past generations of mask registration tools were not necessarily limited in their tool stability, but in their resolution capabilities. The scope of this work is an image placement investigation of high-end EUV masks together with a registration and resolution performance qualification. For this we employ a new generation registration metrology system embedded in a production environment for full-spec EUV masks. This paper presents excellent registration performance not only on standard overlay markers but also on more sophisticated e-beam calibration patterns.

Comparison of manual vs. automated multimodality (CT-MRI) image registration for brain tumors

International Nuclear Information System (INIS)

Sarkar, Abhirup; Santiago, Roberto J.; Smith, Ryan; Kassaee, Alireza

2005-01-01

Computed tomgoraphy-magnetic resonance imaging (CT-MRI) registrations are routinely used for target-volume delineation of brain tumors. We clinically use 2 software packages based on manual operation and 1 automated package with 2 different algorithms: chamfer matching using bony structures, and mutual information using intensity patterns. In all registration algorithms, a minimum of 3 pairs of identical anatomical and preferably noncoplanar landmarks is used on each of the 2 image sets. In manual registration, the program registers these points and links the image sets using a 3-dimensional (3D) transformation. In automated registration, the 3 landmarks are used as an initial starting point and further processing is done to complete the registration. Using our registration packages, registration of CT and MRI was performed on 10 patients. We scored the results of each registration set based on the amount of time spent, the accuracy reported by the software, and a final evaluation. We evaluated each software program by measuring the residual error between 'matched' points on the right and left globes and the posterior fossa for fused image slices. In general, manual registration showed higher misalignment between corresponding points compared to automated registration using intensity matching. This error had no directional dependence and was, most of the time, larger for a larger structure in both registration techniques. Automated algorithm based on intensity matching also gave the best results in terms of registration accuracy, irrespective of whether or not the initial landmarks were chosen carefully, when compared to that done using bone matching algorithm. Intensity-matching algorithm required the least amount of user-time and provided better accuracy

78 FR 64019 - Manufacturer of Controlled Substances, Notice of Registration, Austin Pharma, LLC.

Science.gov (United States)

2013-10-25

..., Notice of Registration, Austin Pharma, LLC. By Notice dated May 14, 2013, and published in the Federal Register on May 22, 2013, 78 FR 30332, Austin Pharma, LLC., 811 Paloma Drive, Suite C, Round Rock, Texas... this drug code is authorized for this registration. On August 9, 2013, Austin Pharma, LLC., withdrew...

Registration accuracy and quality of real-life images.

Directory of Open Access Journals (Sweden)

Wei-Yen Hsu

Full Text Available BACKGROUND: A common registration problem for the application of consumer device is to align all the acquired image sequences into a complete scene. Image alignment requires a registration algorithm that will compensate as much as possible for geometric variability among images. However, images captured views from a real scene usually produce different distortions. Some are derived from the optic characteristics of image sensors, and others are caused by the specific scenes and objects. METHODOLOGY/PRINCIPAL FINDINGS: An image registration algorithm considering the perspective projection is proposed for the application of consumer devices in this study. It exploits a multiresolution wavelet-based method to extract significant features. An analytic differential approach is then proposed to achieve fast convergence of point matching. Finally, the registration accuracy is further refined to obtain subpixel precision by a feature-based modified Levenberg-Marquardt method. Due to its feature-based and nonlinear characteristic, it converges considerably faster than most other methods. In addition, vignette compensation and color difference adjustment are also performed to further improve the quality of registration results. CONCLUSIONS/SIGNIFICANCE: The performance of the proposed method is evaluated by testing the synthetic and real images acquired by a hand-held digital still camera and in comparison with two registration techniques in terms of the squared sum of intensity differences (SSD and correlation coefficient (CC. The results indicate that the proposed method is promising in registration accuracy and quality, which are statistically significantly better than other two approaches.

Development of the image registration program for portal and DRR images in radiation therapy

International Nuclear Information System (INIS)

Watanabe, Hiroyuki; Ito, Takeshi; Nakazeko, Kazuma; Tachibana, Atsuhi; Hashimoto, Takeyuki; Shinohara, Hiroyuki

2012-01-01

In this article, the authors propose an image registration program of portal images and digitally reconstructed radiography (DRR) images used as simulation images for external beam radiation therapy planning. First, the center of the radiation field in a portal image taken using a computed radiograhy cassette is matched to the center of the portal image. Then scale points projected on a DRR image and the portal image are deleted, and the portal image with the radiation field is extracted. Registration of the DRR and portal images is performed using mutual information as the registration criterion. It was found that the absolute displacement misregistrations in two directions (x, y) were 1.2±0.7 mm and 0.5±0.3 mm, respectively, and rotation disagreement about the z axis 0.3±0.3deg. It was concluded the proposed method was applicable to image registration of portal and DRR images in radiation therapy. (author)

Position tracking of moving liver lesion based on real-time registration between 2D ultrasound and 3D preoperative images

International Nuclear Information System (INIS)

Weon, Chijun; Hyun Nam, Woo; Lee, Duhgoon; Ra, Jong Beom; Lee, Jae Young

2015-01-01

Purpose: Registration between 2D ultrasound (US) and 3D preoperative magnetic resonance (MR) (or computed tomography, CT) images has been studied recently for US-guided intervention. However, the existing techniques have some limits, either in the registration speed or the performance. The purpose of this work is to develop a real-time and fully automatic registration system between two intermodal images of the liver, and subsequently an indirect lesion positioning/tracking algorithm based on the registration result, for image-guided interventions. Methods: The proposed position tracking system consists of three stages. In the preoperative stage, the authors acquire several 3D preoperative MR (or CT) images at different respiratory phases. Based on the transformations obtained from nonrigid registration of the acquired 3D images, they then generate a 4D preoperative image along the respiratory phase. In the intraoperative preparatory stage, they properly attach a 3D US transducer to the patient’s body and fix its pose using a holding mechanism. They then acquire a couple of respiratory-controlled 3D US images. Via the rigid registration of these US images to the 3D preoperative images in the 4D image, the pose information of the fixed-pose 3D US transducer is determined with respect to the preoperative image coordinates. As feature(s) to use for the rigid registration, they may choose either internal liver vessels or the inferior vena cava. Since the latter is especially useful in patients with a diffuse liver disease, the authors newly propose using it. In the intraoperative real-time stage, they acquire 2D US images in real-time from the fixed-pose transducer. For each US image, they select candidates for its corresponding 2D preoperative slice from the 4D preoperative MR (or CT) image, based on the predetermined pose information of the transducer. The correct corresponding image is then found among those candidates via real-time 2D registration based on a

An atlas-based multimodal registration method for 2D images with discrepancy structures.

Science.gov (United States)

Lv, Wenchao; Chen, Houjin; Peng, Yahui; Li, Yanfeng; Li, Jupeng

2018-06-04

An atlas-based multimodal registration method for 2-dimension images with discrepancy structures was proposed in this paper. Atlas was utilized for complementing the discrepancy structure information in multimodal medical images. The scheme includes three steps: floating image to atlas registration, atlas to reference image registration, and field-based deformation. To evaluate the performance, a frame model, a brain model, and clinical images were employed in registration experiments. We measured the registration performance by the squared sum of intensity differences. Results indicate that this method is robust and performs better than the direct registration for multimodal images with discrepancy structures. We conclude that the proposed method is suitable for multimodal images with discrepancy structures. Graphical Abstract An Atlas-based multimodal registration method schematic diagram.

Information from the Registration Service

CERN Multimedia

GS Department

2011-01-01

Please note that the Registration Service (Bldg 55-1st floor) will be exceptionally open during the annual end of year closure from 10:00 to 12:00 on the following days: 22, 23, 26, 27,28, 29 et 30 December 2011 and 2,3, et 4 January 2012. All the activities related to the Registration Service will be operational: registration for contractors’ personnel; registrations for professional visits; access cards; car stickers; biometric registration. The Registration Service

Registration of retinal sequences from new video-ophthalmoscopic camera.

Science.gov (United States)

Kolar, Radim; Tornow, Ralf P; Odstrcilik, Jan; Liberdova, Ivana

2016-05-20

Analysis of fast temporal changes on retinas has become an important part of diagnostic video-ophthalmology. It enables investigation of the hemodynamic processes in retinal tissue, e.g. blood-vessel diameter changes as a result of blood-pressure variation, spontaneous venous pulsation influenced by intracranial-intraocular pressure difference, blood-volume changes as a result of changes in light reflection from retinal tissue, and blood flow using laser speckle contrast imaging. For such applications, image registration of the recorded sequence must be performed. Here we use a new non-mydriatic video-ophthalmoscope for simple and fast acquisition of low SNR retinal sequences. We introduce a novel, two-step approach for fast image registration. The phase correlation in the first stage removes large eye movements. Lucas-Kanade tracking in the second stage removes small eye movements. We propose robust adaptive selection of the tracking points, which is the most important part of tracking-based approaches. We also describe a method for quantitative evaluation of the registration results, based on vascular tree intensity profiles. The achieved registration error evaluated on 23 sequences (5840 frames) is 0.78 ± 0.67 pixels inside the optic disc and 1.39 ± 0.63 pixels outside the optic disc. We compared the results with the commonly used approaches based on Lucas-Kanade tracking and scale-invariant feature transform, which achieved worse results. The proposed method can efficiently correct particular frames of retinal sequences for shift and rotation. The registration results for each frame (shift in X and Y direction and eye rotation) can also be used for eye-movement evaluation during single-spot fixation tasks.

Automated landmark-guided deformable image registration.

Science.gov (United States)

Kearney, Vasant; Chen, Susie; Gu, Xuejun; Chiu, Tsuicheng; Liu, Honghuan; Jiang, Lan; Wang, Jing; Yordy, John; Nedzi, Lucien; Mao, Weihua

2015-01-07

The purpose of this work is to develop an automated landmark-guided deformable image registration (LDIR) algorithm between the planning CT and daily cone-beam CT (CBCT) with low image quality. This method uses an automated landmark generation algorithm in conjunction with a local small volume gradient matching search engine to map corresponding landmarks between the CBCT and the planning CT. The landmarks act as stabilizing control points in the following Demons deformable image registration. LDIR is implemented on graphics processing units (GPUs) for parallel computation to achieve ultra fast calculation. The accuracy of the LDIR algorithm has been evaluated on a synthetic case in the presence of different noise levels and data of six head and neck cancer patients. The results indicate that LDIR performed better than rigid registration, Demons, and intensity corrected Demons for all similarity metrics used. In conclusion, LDIR achieves high accuracy in the presence of multimodality intensity mismatch and CBCT noise contamination, while simultaneously preserving high computational efficiency.

Automated landmark-guided deformable image registration

International Nuclear Information System (INIS)

Kearney, Vasant; Chen, Susie; Gu, Xuejun; Chiu, Tsuicheng; Liu, Honghuan; Jiang, Lan; Wang, Jing; Yordy, John; Nedzi, Lucien; Mao, Weihua

2015-01-01

The purpose of this work is to develop an automated landmark-guided deformable image registration (LDIR) algorithm between the planning CT and daily cone-beam CT (CBCT) with low image quality. This method uses an automated landmark generation algorithm in conjunction with a local small volume gradient matching search engine to map corresponding landmarks between the CBCT and the planning CT. The landmarks act as stabilizing control points in the following Demons deformable image registration. LDIR is implemented on graphics processing units (GPUs) for parallel computation to achieve ultra fast calculation. The accuracy of the LDIR algorithm has been evaluated on a synthetic case in the presence of different noise levels and data of six head and neck cancer patients. The results indicate that LDIR performed better than rigid registration, Demons, and intensity corrected Demons for all similarity metrics used. In conclusion, LDIR achieves high accuracy in the presence of multimodality intensity mismatch and CBCT noise contamination, while simultaneously preserving high computational efficiency. (paper)

Motion tracking in the liver: Validation of a method based on 4D ultrasound using a nonrigid registration technique

Energy Technology Data Exchange (ETDEWEB)

Vijayan, Sinara, E-mail: sinara.vijayan@ntnu.no [Norwegian University of Science and Technology, 7491 Trondheim (Norway); Klein, Stefan [Norwegian University of Science and Technology, 7491 Trondheim, Norway and Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC, 3000 CA Rotterdam (Netherlands); Hofstad, Erlend Fagertun; Langø, Thomas [SINTEF, Department Medical Technology, 7465 Trondheim (Norway); Lindseth, Frank [Norwegian University of Science and Technology, 7491 Trondheim, Norway and SINTEF, Department Medical Technology, 7465 Trondheim (Norway); Ystgaard, Brynjulf [Department of Surgery, St. Olavs Hospital, 7030 Trondheim (Norway)

2014-08-15

Purpose: Treatments like radiotherapy and focused ultrasound in the abdomen require accurate motion tracking, in order to optimize dosage delivery to the target and minimize damage to critical structures and healthy tissues around the target. 4D ultrasound is a promising modality for motion tracking during such treatments. In this study, the authors evaluate the accuracy of motion tracking in the liver based on deformable registration of 4D ultrasound images. Methods: The offline analysis was performed using a nonrigid registration algorithm that was specifically designed for motion estimation from dynamic imaging data. The method registers the entire 4D image data sequence in a groupwise optimization fashion, thus avoiding a bias toward a specifically chosen reference time point. Three healthy volunteers were scanned over several breathing cycles (12 s) from three different positions and angles on the abdomen; a total of nine 4D scans for the three volunteers. Well-defined anatomic landmarks were manually annotated in all 96 time frames for assessment of the automatic algorithm. The error of the automatic motion estimation method was compared with interobserver variability. The authors also performed experiments to investigate the influence of parameters defining the deformation field flexibility and evaluated how well the method performed with a lower temporal resolution in order to establish the minimum frame rate required for accurate motion estimation. Results: The registration method estimated liver motion with an error of 1 mm (75% percentile over all datasets), which was lower than the interobserver variability of 1.4 mm. The results were only slightly dependent on the degrees of freedom of the deformation model. The registration error increased to 2.8 mm with an eight times lower temporal resolution. Conclusions: The authors conclude that the methodology was able to accurately track the motion of the liver in the 4D ultrasound data. The authors believe

Accuracy of deformable image registration on magnetic resonance images in digital and physical phantoms.

Science.gov (United States)

Ger, Rachel B; Yang, Jinzhong; Ding, Yao; Jacobsen, Megan C; Fuller, Clifton D; Howell, Rebecca M; Li, Heng; Jason Stafford, R; Zhou, Shouhao; Court, Laurence E

2017-10-01

Accurate deformable image registration is necessary for longitudinal studies. The error associated with commercial systems has been evaluated using computed tomography (CT). Several in-house algorithms have been evaluated for use with magnetic resonance imaging (MRI), but there is still relatively little information about MRI deformable image registration. This work presents an evaluation of two deformable image registration systems, one commercial (Velocity) and one in-house (demons-based algorithm), with MRI using two different metrics to quantify the registration error. The registration error was analyzed with synthetic MR images. These images were generated from interpatient and intrapatient variation models trained on 28 patients. Four synthetic post-treatment images were generated for each of four synthetic pretreatment images, resulting in 16 image registrations for both the T1- and T2-weighted images. The synthetic post-treatment images were registered to their corresponding synthetic pretreatment image. The registration error was calculated between the known deformation vector field and the generated deformation vector field from the image registration system. The registration error was also analyzed using a porcine phantom with ten implanted 0.35-mm diameter gold markers. The markers were visible on CT but not MRI. CT, T1-weighted MR, and T2-weighted MR images were taken in four different positions. The markers were contoured on the CT images and rigidly registered to their corresponding MR images. The MR images were deformably registered and the distance between the projected marker location and true marker location was measured as the registration error. The synthetic images were evaluated only on Velocity. Root mean square errors (RMSEs) of 0.76 mm in the left-right (LR) direction, 0.76 mm in the anteroposterior (AP) direction, and 0.69 mm in the superior-inferior (SI) direction were observed for the T1-weighted MR images. RMSEs of 1.1 mm in the LR

Evaluation of geometric changes of parotid glands during head and neck cancer radiotherapy using daily MVCT and automatic deformable registration

International Nuclear Information System (INIS)

Lee, Choonik; Langen, Katja M.; Lu, Weiguo; Haimerl, Jason; Schnarr, Eric; Ruchala, Kenneth J.; Olivera, Gustavo H.; Meeks, Sanford L.; Kupelian, Patrick A.; Shellenberger, Thomas D.; Manon, Rafael R.

2008-01-01

Background and purpose: To assess and evaluate geometrical changes in parotid glands using deformable image registration and megavoltage CT (MVCT) images. Methods: A deformable registration algorithm was applied to 330 daily MVCT images (10 patients) to create deformed parotid contours. The accuracy and robustness of the algorithm was evaluated through visual review, comparison with manual contours, and precision analysis. Temporal changes in the parotid gland geometry were observed. Results: The deformed parotid contours were qualitatively judged to be acceptable. Compared with manual contours, the uncertainties of automatically deformed contours were similar with regard to geometry and dosimetric endpoint. The day-to-day variations (1 standard deviation of errors) in the center-of-mass distance and volume were 1.61 mm and 4.36%, respectively. The volumes tended to decrease with a median total loss of 21.3% (6.7-31.5%) and a median change rate of 0.7%/day (0.4-1.3%/day). Parotids migrated toward the patient center with a median total distance change of -5.26 mm (0.00 to -16.35 mm) and a median change rate of -0.22 mm/day (0.02 to -0.56 mm/day). Conclusion: The deformable image registration and daily MVCT images provide an efficient and reliable assessment of parotid changes over the course of a radiation therapy

Tensor-based morphometry with stationary velocity field diffeomorphic registration: application to ADNI.

Science.gov (United States)

Bossa, Matias; Zacur, Ernesto; Olmos, Salvador

2010-07-01

Tensor-based morphometry (TBM) is an analysis technique where anatomical information is characterized by means of the spatial transformations mapping a customized template with the observed images. Therefore, accurate inter-subject non-rigid registration is an essential prerequisite for both template estimation and image warping. Subsequent statistical analysis on the spatial transformations is performed to highlight voxel-wise differences. Most of previous TBM studies did not explore the influence of the registration parameters, such as the parameters defining the deformation and the regularization models. In this work performance evaluation of TBM using stationary velocity field (SVF) diffeomorphic registration was performed in a subset of subjects from Alzheimer's Disease Neuroimaging Initiative (ADNI) study. A wide range of values of the registration parameters that define the transformation smoothness and the balance between image matching and regularization were explored in the evaluation. The proposed methodology provided brain atrophy maps with very detailed anatomical resolution and with a high significance level compared with results recently published on the same data set using a non-linear elastic registration method. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Diffusion Maps for Multimodal Registration

Directory of Open Access Journals (Sweden)

Gemma Piella

2014-06-01

Full Text Available Multimodal image registration is a difficult task, due to the significant intensity variations between the images. A common approach is to use sophisticated similarity measures, such as mutual information, that are robust to those intensity variations. However, these similarity measures are computationally expensive and, moreover, often fail to capture the geometry and the associated dynamics linked with the images. Another approach is the transformation of the images into a common space where modalities can be directly compared. Within this approach, we propose to register multimodal images by using diffusion maps to describe the geometric and spectral properties of the data. Through diffusion maps, the multimodal data is transformed into a new set of canonical coordinates that reflect its geometry uniformly across modalities, so that meaningful correspondences can be established between them. Images in this new representation can then be registered using a simple Euclidean distance as a similarity measure. Registration accuracy was evaluated on both real and simulated brain images with known ground-truth for both rigid and non-rigid registration. Results showed that the proposed approach achieved higher accuracy than the conventional approach using mutual information.

21 CFR 1301.52 - Termination of registration; transfer of registration; distribution upon discontinuance of business.

Science.gov (United States)

2010-04-01

... discontinues business or professional practice. Any registrant who ceases legal existence or discontinues... registration; distribution upon discontinuance of business. 1301.52 Section 1301.52 Food and Drugs DRUG... of registration; transfer of registration; distribution upon discontinuance of business. (a) Except...

Evaluation of the mutual information cost function for registration of SPET and MRI images of the brain

International Nuclear Information System (INIS)

Taleb, M.; McKay, E.

1999-01-01

Full text: Any strategy for image registration requires some method (a cost function) by which two images may be compared The mutual information (MI) between images is one such cost function. MI measures the structural similarity between pairs of gray-scale images and performs cross-modality image registration with minimal image pre-processing. This project compares the performance of MI vs the sum of absolute differences (SAD) 'gold standard' in monomodality image registration problems. It also examines the precision of cross-modality registration based on MI, using a human observer to decide whether registration is accurate. Thirteen paired brain SPET scans were registered using SAD as a cost function. Registration was repeated using MI and differences from the SAD results were recorded. Ten paired MRI and SPET brain scans registered using the MI cost function. Registration was repeated three times for each pair, varying the SPET position or orientation each time. Comparing MI to SAD, the median values of translation error were 2.85, 4.63 and 2.56 mm in the x, y and z axis and 0.5 j , 1.1 j and 1.0 j around the x, y and z axis respectively. For the cross-modality problems, the mean standard deviation (MSD) observed in x, y and z positioning was 0.18, 0.28 and 0.16 mm respectively. The MSD of orientation was 5.35 j , 1.95 j and 2.48 j around the x, y and z axis respectively. MI performed as well as SAD for monomodality registration. Unlike SAD, MI is also useful for cross-modality image registration tasks, producing visually acceptable results with minimal preprocessing

Registration of SPECT, PET and/or X-ray CT images in patients with lung cancer

International Nuclear Information System (INIS)

Uemura, K.; Toyama, H.; Miyamoto, T.; Yoshikawa, K.; Mori, Y.

2002-01-01

Aim: In order to evaluate the therapeutic gain of heavy ion therapy performed on patients with lung cancer, the regional pulmonary functions and the amount of radio tracer accumulation to the tumor, we are investigated by using the region of interest based on anatomical information obtained from X-ray CT. There are many registration techniques for brain images, but not so much for the other organ images that we have studied registration of chest SPECT, PET and/or X-ray CT images. Materials and Methods: Perfusion, ventilation and blood pool images with Tc 99m labeled radiopharmaceuticals and SPECT, tumor images with 11 C-methionine and PET and X-ray CT scans were performed on several patients with lung cancer before and after heavy ion therapy. The registrations of SPECT-CT, PET-CT and CT-CT were performed by using AMIR (Automatic Multimodality Image Registration), which was developed by Babak et al. for registration of brain images. In a case of SPECT-CT registration, each of the three functional images was registered to the X-ray CT image, and the accuracy of each registration was compared. In the studies of PET-CT registration, the transmission images and X-ray CT images were registered at first, because the 11 C-methionine PET images bear little resemblance to the underlying anatomical images. Next, the emission images were realigned by using the same registration parameters. The X-ray CT images obtained from a single subject at the different time were registered to the first X-ray CT images, respectively. Results: In the SPECT-CT registration, the blood pool-CT registration is the best among three SPECT images in visual inspection by radiologists. In the PET-CT registration, the Transmission-CT registrations got good results. Therefore, Emission-CT registrations also got good results. In the CT-CT registration, the X-ray CT images obtained from a single subject at the different time were superimposed well each other except for lower lobe. As the results, it was

Validation for 2D/3D registration II: The comparison of intensity- and gradient-based merit functions using a new gold standard data set

International Nuclear Information System (INIS)

Gendrin, Christelle; Markelj, Primoz; Pawiro, Supriyanto Ardjo; Spoerk, Jakob; Bloch, Christoph; Weber, Christoph; Figl, Michael; Bergmann, Helmar; Birkfellner, Wolfgang; Likar, Bostjan; Pernus, Franjo

2011-01-01

TRE down to 0.56 and 0.70 mm, respectively). Overall, gradient-based similarity measures were found to be substantially more accurate than intensity-based methods and could cope with soft tissue deformation and enabled also accurate registrations of the MR-T1 volume to the kV x-ray image. Conclusions: In this article, the authors demonstrate the usefulness of a new phantom image data set for the evaluation of 2D/3D registration methods, which featured soft tissue deformation. The author's evaluation shows that gradient-based methods are more accurate than intensity-based methods, especially when soft tissue deformation is present. However, the current nonoptimized implementations make them prohibitively slow for practical applications. On the other hand, the speed of the intensity-based method renders these more suitable for clinical use, while the accuracy is still competitive.

Population based ranking of frameless CT-MRI registration methods

Energy Technology Data Exchange (ETDEWEB)

Opposits, Gabor; Kis, Sandor A.; Tron, Lajos; Emri, Miklos [Debrecen Univ. (Hungary). Dept. of Nuclear Medicine; Berenyi, Ervin [Debrecen Univ. (Hungary). Dept. of Biomedical Laboratory and Imaging Science; Takacs, Endre [Rotating Gamma Ltd., Debrecen (Hungary); Dobai, Jozsef G.; Bognar, Laszlo [Debrecen Univ., Medical Center (Hungary). Dept. of Neurosurgery; Szuecs, Bernadett [ScanoMed Ltd., Debrecen (Hungary)

2015-07-01

Clinical practice often requires simultaneous information obtained by two different imaging modalities. Registration algorithms are commonly used for this purpose. Automated procedures are very helpful in cases when the same kind of registration has to be performed on images of a high number of subjects. Radiotherapists would prefer to use the best automated method to assist therapy planning, however there are not accepted procedures for ranking the different registration algorithms. We were interested in developing a method to measure the population level performance of CT-MRI registration algorithms by a parameter of values in the [0,1] interval. Pairs of CT and MRI images were collected from 1051 subjects. Results of an automated registration were corrected manually until a radiologist and a neurosurgeon expert both accepted the result as good. This way 1051 registered MRI images were produced by the same pair of experts to be used as gold standards for the evaluation of the performance of other registration algorithms. Pearson correlation coefficient, mutual information, normalized mutual information, Kullback-Leibler divergence, L{sub 1} norm and square L{sub 2} norm (dis)similarity measures were tested for sensitivity to indicate the extent of (dis)similarity of a pair of individual mismatched images. The square Hellinger distance proved suitable to grade the performance of registration algorithms at population level providing the developers with a valuable tool to rank algorithms. The developed procedure provides an objective method to find the registration algorithm performing the best on the population level out of newly constructed or available preselected ones.

Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply.

Science.gov (United States)

Criminisi, A; Fontanazza, C M; Freni, G; Loggia, G La

2009-01-01

Apparent losses are usually caused by water theft, billing errors, or revenue meter under-registration. While the first two causes are directly related to water utility management and may be reduced by improving company procedures, water meter inaccuracies are considered to be the most significant and hardest to quantify. Water meter errors are amplified in networks subjected to water scarcity, where users adopt private storage tanks to cope with the intermittent water supply. The aim of this paper is to analyse the role of two variables influencing the apparent losses: water meter age and the private storage tank effect on meter performance. The study was carried out in Palermo (Italy). The impact of water meter ageing was evaluated in laboratory by testing 180 revenue meters, ranging from 0 to 45 years in age. The effects of the private water tanks were determined via field monitoring of real users and a mathematical model. This study demonstrates that the impact on apparent losses from the meter starting flow rapidly increases with meter age. Private water tanks, usually fed by a float valve, overstate meter under-registration, producing additional apparent losses between 15% and 40% for the users analysed in this study.

Less is More : Better Compliance and Increased Revenues by Streamlining Business Registration in Uganda

OpenAIRE

Sander, Cerstin

2003-01-01

A pilot of a streamlined business registration system in Entebbe, Uganda, reduced compliance costs for enterprises by 75 percent, raised registration numbers and fee revenue by 40 percent and reduced the cost of administering the system. It also reduced opportunities for corruption, improved relations between businesses and the local authorities and resulted in better compliance.

Improving Intensity-Based Lung CT Registration Accuracy Utilizing Vascular Information

Directory of Open Access Journals (Sweden)

Kunlin Cao

2012-01-01

Full Text Available Accurate pulmonary image registration is a challenging problem when the lungs have a deformation with large distance. In this work, we present a nonrigid volumetric registration algorithm to track lung motion between a pair of intrasubject CT images acquired at different inflation levels and introduce a new vesselness similarity cost that improves intensity-only registration. Volumetric CT datasets from six human subjects were used in this study. The performance of four intensity-only registration algorithms was compared with and without adding the vesselness similarity cost function. Matching accuracy was evaluated using landmarks, vessel tree, and fissure planes. The Jacobian determinant of the transformation was used to reveal the deformation pattern of local parenchymal tissue. The average matching error for intensity-only registration methods was on the order of 1 mm at landmarks and 1.5 mm on fissure planes. After adding the vesselness preserving cost function, the landmark and fissure positioning errors decreased approximately by 25% and 30%, respectively. The vesselness cost function effectively helped improve the registration accuracy in regions near thoracic cage and near the diaphragm for all the intensity-only registration algorithms tested and also helped produce more consistent and more reliable patterns of regional tissue deformation.

Hand-eye calibration using a target registration error model.

Science.gov (United States)

Chen, Elvis C S; Morgan, Isabella; Jayarathne, Uditha; Ma, Burton; Peters, Terry M

2017-10-01

Surgical cameras are prevalent in modern operating theatres and are often used as a surrogate for direct vision. Visualisation techniques (e.g. image fusion) made possible by tracking the camera require accurate hand-eye calibration between the camera and the tracking system. The authors introduce the concept of 'guided hand-eye calibration', where calibration measurements are facilitated by a target registration error (TRE) model. They formulate hand-eye calibration as a registration problem between homologous point-line pairs. For each measurement, the position of a monochromatic ball-tip stylus (a point) and its projection onto the image (a line) is recorded, and the TRE of the resulting calibration is predicted using a TRE model. The TRE model is then used to guide the placement of the calibration tool, so that the subsequent measurement minimises the predicted TRE. Assessing TRE after each measurement produces accurate calibration using a minimal number of measurements. As a proof of principle, they evaluated guided calibration using a webcam and an endoscopic camera. Their endoscopic camera results suggest that millimetre TRE is achievable when at least 15 measurements are acquired with the tracker sensor ∼80 cm away on the laparoscope handle for a target ∼20 cm away from the camera.

Registration of whole immunohistochemical slide images: an efficient way to characterize biomarker colocalization.

Science.gov (United States)

Moles Lopez, Xavier; Barbot, Paul; Van Eycke, Yves-Rémi; Verset, Laurine; Trépant, Anne-Laure; Larbanoix, Lionel; Salmon, Isabelle; Decaestecker, Christine

2015-01-01

Extracting accurate information from complex biological processes involved in diseases, such as cancers, requires the simultaneous targeting of multiple proteins and locating their respective expression in tissue samples. This information can be collected by imaging and registering adjacent sections from the same tissue sample and stained by immunohistochemistry (IHC). Registration accuracy should be on the scale of a few cells to enable protein colocalization to be assessed. We propose a simple and efficient method based on the open-source elastix framework to register virtual slides of adjacent sections from the same tissue sample. We characterize registration accuracies for different types of tissue and IHC staining. Our results indicate that this technique is suitable for the evaluation of the colocalization of biomarkers on the scale of a few cells. We also show that using this technique in conjunction with a sequential IHC labeling and erasing technique offers improved registration accuracies. Brightfield IHC enables to address the problem of large series of tissue samples, which are usually required in clinical research. However, this approach, which is simple at the tissue processing level, requires challenging image analysis processes, such as accurate registration, to view and extract the protein colocalization information. The method proposed in this work enables accurate registration (on the scale of a few cells) of virtual slides of adjacent tissue sections on which the expression of different proteins is evidenced by standard IHC. Furthermore, combining our method with a sequential labeling and erasing technique enables cell-scale colocalization. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.comFor numbered affiliations see end of article.

Fast free-form deformable registration via calculus of variations

International Nuclear Information System (INIS)

Lu Weiguo; Chen Mingli; Olivera, Gustavo H; Ruchala, Kenneth J; Mackie, Thomas R

2004-01-01

In this paper, we present a fully automatic, fast and accurate deformable registration technique. This technique deals with free-form deformation. It minimizes an energy functional that combines both similarity and smoothness measures. By using calculus of variations, the minimization problem was represented as a set of nonlinear elliptic partial differential equations (PDEs). A Gauss-Seidel finite difference scheme is used to iteratively solve the PDE. The registration is refined by a multi-resolution approach. The whole process is fully automatic. It takes less than 3 min to register two three-dimensional (3D) image sets of size 256 x 256 x 61 using a single 933 MHz personal computer. Extensive experiments are presented. These experiments include simulations, phantom studies and clinical image studies. Experimental results show that our model and algorithm are suited for registration of temporal images of a deformable body. The registration of inspiration and expiration phases of the lung images shows that the method is able to deal with large deformations. When applied to the daily CT images of a prostate patient, the results show that registration based on iterative refinement of displacement field is appropriate to describe the local deformations in the prostate and the rectum. Similarity measures improved significantly after the registration. The target application of this paper is for radiotherapy treatment planning and evaluation that incorporates internal organ deformation throughout the course of radiation therapy. The registration method could also be equally applied in diagnostic radiology

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.

Fusion of dynamic contrast-enhanced magnetic resonance mammography at 3.0 T with X-ray mammograms: Pilot study evaluation using dedicated semi-automatic registration software

Energy Technology Data Exchange (ETDEWEB)

Dietzel, Matthias, E-mail: dietzelmatthias2@hotmail.com [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, D-07740 Jena (Germany); Hopp, Torsten; Ruiter, Nicole [Karlsruhe Institute of Technology (KIT), Institute for Data Processing and Electronics, Postfach 3640, D-76021 Karlsruhe (Germany); Zoubi, Ramy [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, D-07740 Jena (Germany); Runnebaum, Ingo B. [Clinic of Gynecology and Obstetrics, Friedrich-Schiller-University Jena, Bachstrasse 18, D-07743 Jena (Germany); Kaiser, Werner A. [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, D-07740 Jena (Germany); Medical School, University of Harvard, 25 Shattuck Street, Boston, MA 02115 (United States); Baltzer, Pascal A.T. [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, D-07740 Jena (Germany)

2011-08-15

Rationale and objectives: To evaluate the semi-automatic image registration accuracy of X-ray-mammography (XR-M) with high-resolution high-field (3.0 T) MR-mammography (MR-M) in an initial pilot study. Material and methods: MR-M was acquired on a high-field clinical scanner at 3.0 T (T1-weighted 3D VIBE {+-} Gd). XR-M was obtained with state-of-the-art full-field digital systems. Seven patients with clearly delineable mass lesions >10 mm both in XR-M and MR-M were enrolled (exclusion criteria: previous breast surgery; surgical intervention between XR-M and MR-M). XR-M and MR-M were matched using a dedicated image-registration algorithm allowing semi-automatic non-linear deformation of MR-M based on finite-element modeling. To identify registration errors (RE) a virtual craniocaudal 2D mammogram was calculated by the software from MR-M (with and w/o Gadodiamide/Gd) and matched with corresponding XR-M. To quantify REs the geometric center of the lesions in the virtual vs. conventional mammogram were subtracted. The robustness of registration was quantified by registration of X-MRs to both MR-Ms with and w/o Gadodiamide. Results: Image registration was performed successfully for all patients. Overall RE was 8.2 mm (1 min after Gd; confidence interval/CI: 2.0-14.4 mm, standard deviation/SD: 6.7 mm) vs. 8.9 mm (no Gd; CI: 4.0-13.9 mm, SD: 5.4 mm). The mean difference between pre- vs. post-contrast was 0.7 mm (SD: 1.9 mm). Conclusion: Image registration of high-field 3.0 T MR-mammography with X-ray-mammography is feasible. For this study applying a high-resolution protocol at 3.0 T, the registration was robust and the overall registration error was sufficient for clinical application.

Fusion of dynamic contrast-enhanced magnetic resonance mammography at 3.0 T with X-ray mammograms: Pilot study evaluation using dedicated semi-automatic registration software

International Nuclear Information System (INIS)

Dietzel, Matthias; Hopp, Torsten; Ruiter, Nicole; Zoubi, Ramy; Runnebaum, Ingo B.; Kaiser, Werner A.; Baltzer, Pascal A.T.

2011-01-01

Rationale and objectives: To evaluate the semi-automatic image registration accuracy of X-ray-mammography (XR-M) with high-resolution high-field (3.0 T) MR-mammography (MR-M) in an initial pilot study. Material and methods: MR-M was acquired on a high-field clinical scanner at 3.0 T (T1-weighted 3D VIBE ± Gd). XR-M was obtained with state-of-the-art full-field digital systems. Seven patients with clearly delineable mass lesions >10 mm both in XR-M and MR-M were enrolled (exclusion criteria: previous breast surgery; surgical intervention between XR-M and MR-M). XR-M and MR-M were matched using a dedicated image-registration algorithm allowing semi-automatic non-linear deformation of MR-M based on finite-element modeling. To identify registration errors (RE) a virtual craniocaudal 2D mammogram was calculated by the software from MR-M (with and w/o Gadodiamide/Gd) and matched with corresponding XR-M. To quantify REs the geometric center of the lesions in the virtual vs. conventional mammogram were subtracted. The robustness of registration was quantified by registration of X-MRs to both MR-Ms with and w/o Gadodiamide. Results: Image registration was performed successfully for all patients. Overall RE was 8.2 mm (1 min after Gd; confidence interval/CI: 2.0-14.4 mm, standard deviation/SD: 6.7 mm) vs. 8.9 mm (no Gd; CI: 4.0-13.9 mm, SD: 5.4 mm). The mean difference between pre- vs. post-contrast was 0.7 mm (SD: 1.9 mm). Conclusion: Image registration of high-field 3.0 T MR-mammography with X-ray-mammography is feasible. For this study applying a high-resolution protocol at 3.0 T, the registration was robust and the overall registration error was sufficient for clinical application.

Registration of indoor TLS data: in favor of a probabilistic approach initialized by geo-location

International Nuclear Information System (INIS)

Hullo, Jean-Francois

2013-01-01

Many pre-maintenance operations of industrial facilities currently resort on to three dimensional CAD models. The acquisition of these models is performed from point clouds measured by Terrestrial Laser Scanning (TLS). When the scenes are complex, several view points for scanning, also known as stations, are necessary to ensure the completeness and the density of the survey data. The generation of a global point cloud, i.e. the expression of all the acquired data in a common reference frame, is a crucial step called registration. During this process, the pose parameters are estimated. If the GNSS Systems are now a solution for many outdoor scenes, the registration of indoor TLS data still remains a challenge. The goal of this thesis is to improve the acquisition process of TLS data in industrial environments. The aim is to guarantee the precision and accuracy of acquired data, while optimizing on-site acquisition time and protocols by, as often as possible, freeing the operator from the constraints inherent to conventional topography surveys. In a first part, we consider the state of the art of the means and methods used during the acquisition of dense point clouds of complex interior scenes (Part I). In a second part, we study and evaluate the data available for the registration: terrestrial laser data, primitive reconstruction algorithms in point clouds and indoor geo-location Systems (Part II). In the third part, we then formalize and experiment a registration algorithm based on the use of matched primitives, reconstructed from per station point clouds ( Part III). We finally propose a probabilistic approach for matching primitives, allowing the integration of a priori information and uncertainty in the constraints System used for calculating poses (Part IV). The contributions of our work are as follows: - to take a critical look at current methods of TLS data acquisition in industrial environments, - to evaluate, through experimentations, the information

Image registration with uncertainty analysis

Science.gov (United States)

Simonson, Katherine M [Cedar Crest, NM

2011-03-22

In an image registration method, edges are detected in a first image and a second image. A percentage of edge pixels in a subset of the second image that are also edges in the first image shifted by a translation is calculated. A best registration point is calculated based on a maximum percentage of edges matched. In a predefined search region, all registration points other than the best registration point are identified that are not significantly worse than the best registration point according to a predetermined statistical criterion.

Vision-based markerless registration using stereo vision and an augmented reality surgical navigation system: a pilot study

International Nuclear Information System (INIS)

Suenaga, Hideyuki; Tran, Huy Hoang; Liao, Hongen; Masamune, Ken; Dohi, Takeyoshi; Hoshi, Kazuto; Takato, Tsuyoshi

2015-01-01

This study evaluated the use of an augmented reality navigation system that provides a markerless registration system using stereo vision in oral and maxillofacial surgery. A feasibility study was performed on a subject, wherein a stereo camera was used for tracking and markerless registration. The computed tomography data obtained from the volunteer was used to create an integral videography image and a 3-dimensional rapid prototype model of the jaw. The overlay of the subject’s anatomic site and its 3D-IV image were displayed in real space using a 3D-AR display. Extraction of characteristic points and teeth matching were done using parallax images from two stereo cameras for patient-image registration. Accurate registration of the volunteer’s anatomy with IV stereoscopic images via image matching was done using the fully automated markerless system, which recognized the incisal edges of the teeth and captured information pertaining to their position with an average target registration error of < 1 mm. These 3D-CT images were then displayed in real space with high accuracy using AR. Even when the viewing position was changed, the 3D images could be observed as if they were floating in real space without using special glasses. Teeth were successfully used for registration via 3D image (contour) matching. This system, without using references or fiducial markers, displayed 3D-CT images in real space with high accuracy. The system provided real-time markerless registration and 3D image matching via stereo vision, which, combined with AR, could have significant clinical applications. The online version of this article (doi:10.1186/s12880-015-0089-5) contains supplementary material, which is available to authorized users

A Remote Registration Based on MIDAS

Science.gov (United States)

JIN, Xin

2017-04-01

We often need for software registration to protect the interests of the software developers. This article narrated one kind of software long-distance registration technology. The registration method is: place the registration information in a database table, after the procedure starts in check table registration information, if it has registered then the procedure may the normal operation; Otherwise, the customer must input the sequence number and registers through the network on the long-distance server. If it registers successfully, then records the registration information in the database table. This remote registration method can protect the rights of software developers.

Registration concepts for the just-in-time artefact correction by means of virtual computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kasperl, St.; Franz, M. [Fraunhofer Development Center for X-ray Technology EZRT, a cooperative dept. of the Fraunhofer Institutes IZFP Saarbrucken and IIS Erlangen, Furth (Germany)

2007-07-01

This article deals with the enhancement of accuracy in CT by just-in-time correction of artefacts (beam hardening, scattered radiation) caused by the interaction of X-rays with matter. The so called EAR method needs for simulation a registration of the object. Therefore the article presents two different registration concepts. (authors)

Registration concepts for the just-in-time artefact correction by means of virtual computed tomography

International Nuclear Information System (INIS)

Kasperl, St.; Franz, M.

2007-01-01

This article deals with the enhancement of accuracy in CT by just-in-time correction of artefacts (beam hardening, scattered radiation) caused by the interaction of X-rays with matter. The so called EAR method needs for simulation a registration of the object. Therefore the article presents two different registration concepts. (authors)

A national multicenter registration study. Omalizumb in children in Denmark

DEFF Research Database (Denmark)

Spangberg, Katrien; Jørgensen, Inger Merete; Agertoft, Lone

Background: In Denmark, Omalizumab is approved to treat children with severe persistent allergic asthma older than 6 years of age. No systematic registration of the efficacy in the Danish child population according to asthma symptoms or of the efficacy on co-morbid allergic symptoms exists. Results...... from a pilot study show that a broad panel of outcome measures is necessary to evaluate the efficacy of Omalizumab treatment as no change in lung function could be demonstrated Aim: To provide a standardized systematic registration in order to create a database enrolling children with severe allergic...... asthma treated with Omalizumab. Method and study design: A national multicenter registration and follow-up study based on children with clinical persistent severe allergic asthma including both retrospective and prospective registration. Inclusion criteria: • 6-18 years of age. • Severe persistent...

Significantly reducing registration time in IGRT using graphics processing units

DEFF Research Database (Denmark)

Noe, Karsten Østergaard; Denis de Senneville, Baudouin; Tanderup, Kari

2008-01-01

respiration phases in a free breathing volunteer and 41 anatomical landmark points in each image series. The registration method used is a multi-resolution GPU implementation of the 3D Horn and Schunck algorithm. It is based on the CUDA framework from Nvidia. Results On an Intel Core 2 CPU at 2.4GHz each...... registration took 30 minutes. On an Nvidia Geforce 8800GTX GPU in the same machine this registration took 37 seconds, making the GPU version 48.7 times faster. The nine image series of different respiration phases were registered to the same reference image (full inhale). Accuracy was evaluated on landmark...

Selecting registration schemes in case of interstitial lung disease follow-up in CT

International Nuclear Information System (INIS)

Vlachopoulos, Georgios; Korfiatis, Panayiotis; Skiadopoulos, Spyros; Kazantzi, Alexandra; Kalogeropoulou, Christina; Pratikakis, Ioannis; Costaridou, Lena

2015-01-01

Purpose: Primary goal of this study is to select optimal registration schemes in the framework of interstitial lung disease (ILD) follow-up analysis in CT. Methods: A set of 128 multiresolution schemes composed of multiresolution nonrigid and combinations of rigid and nonrigid registration schemes are evaluated, utilizing ten artificially warped ILD follow-up volumes, originating from ten clinical volumetric CT scans of ILD affected patients, to select candidate optimal schemes. Specifically, all combinations of four transformation models (three rigid: rigid, similarity, affine and one nonrigid: third order B-spline), four cost functions (sum-of-square distances, normalized correlation coefficient, mutual information, and normalized mutual information), four gradient descent optimizers (standard, regular step, adaptive stochastic, and finite difference), and two types of pyramids (recursive and Gaussian-smoothing) were considered. The selection process involves two stages. The first stage involves identification of schemes with deformation field singularities, according to the determinant of the Jacobian matrix. In the second stage, evaluation methodology is based on distance between corresponding landmark points in both normal lung parenchyma (NLP) and ILD affected regions. Statistical analysis was performed in order to select near optimal registration schemes per evaluation metric. Performance of the candidate registration schemes was verified on a case sample of ten clinical follow-up CT scans to obtain the selected registration schemes. Results: By considering near optimal schemes common to all ranking lists, 16 out of 128 registration schemes were initially selected. These schemes obtained submillimeter registration accuracies in terms of average distance errors 0.18 ± 0.01 mm for NLP and 0.20 ± 0.01 mm for ILD, in case of artificially generated follow-up data. Registration accuracy in terms of average distance error in clinical follow-up data was in the

Selecting registration schemes in case of interstitial lung disease follow-up in CT

Energy Technology Data Exchange (ETDEWEB)

Vlachopoulos, Georgios; Korfiatis, Panayiotis; Skiadopoulos, Spyros; Kazantzi, Alexandra [Department of Medical Physics, School of Medicine,University of Patras, Patras 26504 (Greece); Kalogeropoulou, Christina [Department of Radiology, School of Medicine, University of Patras, Patras 26504 (Greece); Pratikakis, Ioannis [Department of Electrical and Computer Engineering, Democritus University of Thrace, Xanthi 67100 (Greece); Costaridou, Lena, E-mail: costarid@upatras.gr [Department of Medical Physics, School of Medicine, University of Patras, Patras 26504 (Greece)

2015-08-15

Purpose: Primary goal of this study is to select optimal registration schemes in the framework of interstitial lung disease (ILD) follow-up analysis in CT. Methods: A set of 128 multiresolution schemes composed of multiresolution nonrigid and combinations of rigid and nonrigid registration schemes are evaluated, utilizing ten artificially warped ILD follow-up volumes, originating from ten clinical volumetric CT scans of ILD affected patients, to select candidate optimal schemes. Specifically, all combinations of four transformation models (three rigid: rigid, similarity, affine and one nonrigid: third order B-spline), four cost functions (sum-of-square distances, normalized correlation coefficient, mutual information, and normalized mutual information), four gradient descent optimizers (standard, regular step, adaptive stochastic, and finite difference), and two types of pyramids (recursive and Gaussian-smoothing) were considered. The selection process involves two stages. The first stage involves identification of schemes with deformation field singularities, according to the determinant of the Jacobian matrix. In the second stage, evaluation methodology is based on distance between corresponding landmark points in both normal lung parenchyma (NLP) and ILD affected regions. Statistical analysis was performed in order to select near optimal registration schemes per evaluation metric. Performance of the candidate registration schemes was verified on a case sample of ten clinical follow-up CT scans to obtain the selected registration schemes. Results: By considering near optimal schemes common to all ranking lists, 16 out of 128 registration schemes were initially selected. These schemes obtained submillimeter registration accuracies in terms of average distance errors 0.18 ± 0.01 mm for NLP and 0.20 ± 0.01 mm for ILD, in case of artificially generated follow-up data. Registration accuracy in terms of average distance error in clinical follow-up data was in the

Image/patient registration from (partial) projection data by the Fourier phase matching method

International Nuclear Information System (INIS)

Weiguo Lu; You, J.

1999-01-01

A technique for 2D or 3D image/patient registration, PFPM (projection based Fourier phase matching method), is proposed. This technique provides image/patient registration directly from sequential tomographic projection data. The method can also deal with image files by generating 2D Radon transforms slice by slice. The registration in projection space is done by calculating a Fourier invariant (FI) descriptor for each one-dimensional projection datum, and then registering the FI descriptor by the Fourier phase matching (FPM) method. The algorithm has been tested on both synthetic and experimental data. When dealing with translated, rotated and uniformly scaled 2D image registration, the performance of the PFPM method is comparable to that of the IFPM (image based Fourier phase matching) method in robustness, efficiency, insensitivity to the offset between images, and registration time. The advantages of the former are that subpixel resolution is feasible, and it is more insensitive to image noise due to the averaging effect of the projection acquisition. Furthermore, the PFPM method offers the ability to generalize to 3D image/patient registration and to register partial projection data. By applying patient registration directly from tomographic projection data, image reconstruction is not needed in the therapy set-up verification, thus reducing computational time and artefacts. In addition, real time registration is feasible. Registration from partial projection data meets the geometry and dose requirements in many application cases and makes dynamic set-up verification possible in tomotherapy. (author)

Image Registration: A Necessary Evil

Science.gov (United States)

Bell, James; McLachlan, Blair; Hermstad, Dexter; Trosin, Jeff; George, Michael W. (Technical Monitor)

1995-01-01

Registration of test and reference images is a key component of nearly all PSP data reduction techniques. This is done to ensure that a test image pixel viewing a particular point on the model is ratioed by the reference image pixel which views the same point. Typically registration is needed to account for model motion due to differing airloads when the wind-off and wind-on images are taken. Registration is also necessary when two cameras are used for simultaneous acquisition of data from a dual-frequency paint. This presentation will discuss the advantages and disadvantages of several different image registration techniques. In order to do so, it is necessary to propose both an accuracy requirement for image registration and a means for measuring the accuracy of a particular technique. High contrast regions in the unregistered images are most sensitive to registration errors, and it is proposed that these regions be used to establish the error limits for registration. Once this is done, the actual registration error can be determined by locating corresponding points on the test and reference images, and determining how well a particular registration technique matches them. An example of this procedure is shown for three transforms used to register images of a semispan model. Thirty control points were located on the model. A subset of the points were used to determine the coefficients of each registration transform, and the error with which each transform aligned the remaining points was determined. The results indicate the general superiority of a third-order polynomial over other candidate transforms, as well as showing how registration accuracy varies with number of control points. Finally, it is proposed that image registration may eventually be done away with completely. As more accurate image resection techniques and more detailed model surface grids become available, it will be possible to map raw image data onto the model surface accurately. Intensity

Evaluation of the performance of deformable image registration between planning CT and CBCT images for the pelvic region: comparison between hybrid and intensity-based DIR.

Science.gov (United States)

Takayama, Yoshiki; Kadoya, Noriyuki; Yamamoto, Takaya; Ito, Kengo; Chiba, Mizuki; Fujiwara, Kousei; Miyasaka, Yuya; Dobashi, Suguru; Sato, Kiyokazu; Takeda, Ken; Jingu, Keiichi

2017-07-01

This study aimed to evaluate the performance of the hybrid deformable image registration (DIR) method in comparison with intensity-based DIR for pelvic cone-beam computed tomography (CBCT) images, using intensity and anatomical information. Ten prostate cancer patients treated with intensity-modulated radiation therapy (IMRT) were studied. Nine or ten CBCT scans were performed for each patient. First, rigid registration was performed between the planning CT and all CBCT images using gold fiducial markers, and then DIR was performed. The Dice similarity coefficient (DSC) and center of mass (COM) displacement were used to evaluate the quantitative DIR accuracy. The average DSCs for intensity-based DIR for the prostate, rectum, bladder, and seminal vesicles were 0.84 ± 0.05, 0.75 ± 0.05, 0.69 ± 0.07 and 0.65 ± 0.11, respectively, whereas those values for hybrid DIR were 0.98 ± 0.00, 0.97 ± 0.01, 0.98 ± 0.00 and 0.94 ± 0.03, respectively (P DSC for hybrid DIR had a higher DSC value and smaller COM displacement for all structures and all patients, compared with intensity-based DIR. Thus, the accumulative dose based on hybrid DIR might be trusted as a high-precision dose estimation method that takes into account organ movement during treatment radiotherapy. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

SU-C-207B-06: Comparison of Registration Methods for Modeling Pathologic Response of Esophageal Cancer to Chemoradiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Riyahi, S; Choi, W; Bhooshan, N; Tan, S; Zhang, H; Lu, W [University of Maryland School of Medicine, Baltimore, MD (United States)

2016-06-15

Purpose: To compare linear and deformable registration methods for evaluation of tumor response to Chemoradiation therapy (CRT) in patients with esophageal cancer. Methods: Linear and multi-resolution BSpline deformable registration were performed on Pre-Post-CRT CT/PET images of 20 patients with esophageal cancer. For both registration methods, we registered CT using Mean Square Error (MSE) metric, however to register PET we used transformation obtained using Mutual Information (MI) from the same CT due to being multi-modality. Similarity of Warped-CT/PET was quantitatively evaluated using Normalized Mutual Information and plausibility of DF was assessed using inverse consistency Error. To evaluate tumor response four groups of tumor features were examined: (1) Conventional PET/CT e.g. SUV, diameter (2) Clinical parameters e.g. TNM stage, histology (3)spatial-temporal PET features that describe intensity, texture and geometry of tumor (4)all features combined. Dominant features were identified using 10-fold cross-validation and Support Vector Machine (SVM) was deployed for tumor response prediction while the accuracy was evaluated by ROC Area Under Curve (AUC). Results: Average and standard deviation of Normalized mutual information for deformable registration using MSE was 0.2±0.054 and for linear registration was 0.1±0.026, showing higher NMI for deformable registration. Likewise for MI metric, deformable registration had 0.13±0.035 comparing to linear counterpart with 0.12±0.037. Inverse consistency error for deformable registration for MSE metric was 4.65±2.49 and for linear was 1.32±2.3 showing smaller value for linear registration. The same conclusion was obtained for MI in terms of inverse consistency error. AUC for both linear and deformable registration was 1 showing no absolute difference in terms of response evaluation. Conclusion: Deformable registration showed better NMI comparing to linear registration, however inverse consistency of

Method of automatic image registration of three-dimensional range of archaeological restoration

International Nuclear Information System (INIS)

Garcia, O.; Perez, M.; Morales, N.

2012-01-01

We propose an automatic registration system for reconstruction of various positions of a large object based on a static structured light pattern. The system combines the technology of stereo vision, structured light pattern, the positioning system of the vision sensor and an algorithm that simplifies the process of finding correspondence for the modeling of large objects. A new structured light pattern based on Kautz sequence is proposed, using this pattern as static implement a proposed new registration method. (Author)

An evaluation of a public health practitioner registration programme: lessons learned for workforce development.

Science.gov (United States)

Rahman, Em; Wills, Jane

2014-09-01

This article explores the lessons learned for workforce development from an evaluation of a regional programme to support the assessment and registration of public health practitioners to the UK Public Health Register (UKPHR) in England. A summative and process evaluation of the public health practitioner programme in Wessex was adopted. Data collection was by an online survey of 32 public health practitioners in the Wessex area and semi-structured interviews with 53 practitioners, programme support, employers and system leaders. All survey respondents perceived regulation of the public health workforce as very important or important. Managers and system leaders saw a register of those fit to practise and able to define themselves as a public health practitioner as a necessary assurance of quality for the public. Yet, because registration is voluntary for practitioners, less value was currently placed on this than on completing a master's qualification. The local programme supports practitioners in the compilation of a retrospective portfolio of evidence that demonstrates fitness to practise; practitioners and managers stated that this does not support current and future learning needs or the needs of those working at a senior level. One of the main purposes of statutory regulation of professionals is to protect the public by an assurance of fitness to practise where there is a potential for harm. The widening role for public health practitioners without any regulation means that there is the risk of inappropriate interventions or erroneous advice. Regulators, policy makers and system leaders need to consider how they can support the development of the public health workforce to gain professional recognition at all levels of public health, including practitioners alongside specialists, and support a professional career framework for the public health system. © Royal Society for Public Health 2014.

Three-dimensional registration methods for multi-modal magnetic resonance neuroimages

International Nuclear Information System (INIS)

Triantafyllou, C.

2001-08-01

topological differences but also for non-linear deformations in size and shape. Validation of the algorithm is carried out on geometrical objects, simulated data and real images to ensure that the important requirements for a topologically useful mapping; invertibility, smoothness of the deformation field and an almost perfect correspondence can be maintained between two image sequences. Finally, the performance of both approaches is compared by their application to clinical data sets of 35 subjects using perfusion-weighted MR images. The results show a significantly higher degree of success for the non-linear algorithm compared with the more conventional global registration method. A clinical evaluation is also presented wherein estimation of tissue parameters in the form of cerebral blood flow in grey and white matter of the brain are evaluated and compared with user-defined ROIs (Regions of Interest). This has the important advantage of providing the means by which to estimate automatically such measures in a reliable way. (author)

12 CFR 998.3 - Reservation of authority.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Reservation of authority. 998.3 Section 998.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK DISCLOSURES REGISTRATION OF FEDERAL HOME LOAN BANK EQUITY SECURITIES § 998.3 Reservation of authority. The requirements of this part...

Implementing service improvement projects within pre-registration nursing education: a multi-method case study evaluation.

Science.gov (United States)

Baillie, Lesley; Bromley, Barbara; Walker, Moira; Jones, Rebecca; Mhlanga, Fortune

2014-01-01

Preparing healthcare students for quality and service improvement is important internationally. A United Kingdom (UK) initiative aims to embed service improvement in pre-registration education. A UK university implemented service improvement teaching for all nursing students. In addition, the degree pathway students conducted service improvement projects as the basis for their dissertations. The study aimed to evaluate the implementation of service improvement projects within a pre-registration nursing curriculum. A multi-method case study was conducted, using student questionnaires, focus groups with students and academic staff, and observation of action learning sets. Questionnaire data were analysed using SPSS v19. Qualitative data were analysed using Ritchie and Spencer's (1994) Framework Approach. Students were very positive about service improvement. The degree students, who conducted service improvement projects in practice, felt more knowledgeable than advanced diploma students. Selecting the project focus was a key issue and students encountered some challenges in practice. Support for student service improvement projects came from action learning sets, placement staff, and academic staff. Service improvement projects had a positive effect on students' learning. An effective partnership between the university and partner healthcare organisations, and support for students in practice, is essential. Copyright © 2013 Elsevier Ltd. All rights reserved.

A systematic review of comparisons between protocols or registrations and full reports in primary biomedical research

Directory of Open Access Journals (Sweden)

Guowei Li

2018-01-01

registrations and full reports of primary biomedical research is frequent, prevalent and suboptimal. We also identified methodological issues such as the need for consensus on measuring inconsistency across sources for trial reports, and more studies evaluating transparency and reproducibility in reporting all aspects of study design and analysis. A joint effort involving authors, journals, sponsors, regulators and research ethics committees is required to solve this problem.

Why and how to make a REACH registration of combustion ash; Moejligheter vid REACH-registrering av energiaskor

Energy Technology Data Exchange (ETDEWEB)

Loevgren, Linnea; Wik, Ola

2009-10-15

The new chemical regulation, REACH (1997/2006/EC), Registration, Evaluation, Authorization and restriction of Chemicals, took effect the 1st of June 2007. The background to this report was the introduction of REACH and the difficulties to understand the implications for ash. The most important consequence of REACH is that all chemical substances that are manufactured, handled and used above one tonne per annum per legal entity shall be registered according to this regulation. The registration includes specifying the chemical, physical, toxicity and ecotoxicity properties of the substance and risk assessing the identified areas of use. The report describes the use of ash in connection to the waste legislation and its planned end-of-waste-criteria, the chemical legislation and the Construction Products Directive. The target audience of this report is companies producing ashes and having a use or seeing a use for its ash. The report describes how to make a REACH registration of ash independent if a company did or did not pre-register ash during 2008. It describes how to change from one ash registration into another if the pre-registration was done for one type of ash but the company changes opinion during the sameness check, i.e. changing SIEF (Appendix A). Taking part in REACH registration projects during 2009-2010 can be advantageous since knowledge and financing are shared. Ash can be REACH registered also in the future but it is important to know that the registration have to be done prior the production and marketing starts. If ash is consider to be a waste the handling is covered by the community and national waste legislation. In Sweden ashes are by and large being regarded as waste, and recycling is risk assessed and permits are given case by case. End-of-waste criteria for different waste material are being elaborated within the EU. Such criteria will among other details cover chemical safety. When a material fulfils the end-of-waste criteria such material

Improving oncoplastic breast tumor bed localization for radiotherapy planning using image registration algorithms

Science.gov (United States)

Wodzinski, Marek; Skalski, Andrzej; Ciepiela, Izabela; Kuszewski, Tomasz; Kedzierawski, Piotr; Gajda, Janusz

2018-02-01

Knowledge about tumor bed localization and its shape analysis is a crucial factor for preventing irradiation of healthy tissues during supportive radiotherapy and as a result, cancer recurrence. The localization process is especially hard for tumors placed nearby soft tissues, which undergo complex, nonrigid deformations. Among them, breast cancer can be considered as the most representative example. A natural approach to improving tumor bed localization is the use of image registration algorithms. However, this involves two unusual aspects which are not common in typical medical image registration: the real deformation field is discontinuous, and there is no direct correspondence between the cancer and its bed in the source and the target 3D images respectively. The tumor no longer exists during radiotherapy planning. Therefore, a traditional evaluation approach based on known, smooth deformations and target registration error are not directly applicable. In this work, we propose alternative artificial deformations which model the tumor bed creation process. We perform a comprehensive evaluation of the most commonly used deformable registration algorithms: B-Splines free form deformations (B-Splines FFD), different variants of the Demons and TV-L1 optical flow. The evaluation procedure includes quantitative assessment of the dedicated artificial deformations, target registration error calculation, 3D contour propagation and medical experts visual judgment. The results demonstrate that the currently, practically applied image registration (rigid registration and B-Splines FFD) are not able to correctly reconstruct discontinuous deformation fields. We show that the symmetric Demons provide the most accurate soft tissues alignment in terms of the ability to reconstruct the deformation field, target registration error and relative tumor volume change, while B-Splines FFD and TV-L1 optical flow are not an appropriate choice for the breast tumor bed localization problem

31 CFR 321.7 - Authorized cash payments.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Authorized cash payments. 321.7 Section 321.7 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL... registration on the front of the security, or by a person authorized or empowered to act for a corporate legal...

Insecticides authorized for use on olive trees and the relationship between their registration and residues in olive oil

Directory of Open Access Journals (Sweden)

Lentza-Rizos, Ch.

1996-12-01

Full Text Available In order to eliminate losses due to insect attack, several insecticides are used on olive trees. Their residues in olive oil constitute an important parameter of its quality and must be monitored regularly and kept as low possible in order to ensure consumer protection. In this paper the insecticides authorized for use on olive trees are listed and their ADIs and Codex Alimentarius MRLs reported. The existing registrations are discussed from the point of view of their residues in oil.

Diversos insecticidas son usados para eliminar las pérdidas debidas al ataque de insectos en olivos. Sus residuos en el aceite de oliva constituyen un parámetro importante de su calidad y deben ser controlados con regularidad y mantenidos tan bajos como sea posible en orden a asegurar la protección del consumidor. En este artículo se incluyen los distintos insecticidas autorizados para su uso en olivos así como los valores de ingesta diaria aceptable para el hombre y los límites máximos autorizados de los mismos. Los registros existentes se discuten desde el punto de vista de sus residuos en el aceite.

Coarse Point Cloud Registration by Egi Matching of Voxel Clusters

Science.gov (United States)

Wang, Jinhu; Lindenbergh, Roderik; Shen, Yueqian; Menenti, Massimo

2016-06-01

Laser scanning samples the surface geometry of objects efficiently and records versatile information as point clouds. However, often more scans are required to fully cover a scene. Therefore, a registration step is required that transforms the different scans into a common coordinate system. The registration of point clouds is usually conducted in two steps, i.e. coarse registration followed by fine registration. In this study an automatic marker-free coarse registration method for pair-wise scans is presented. First the two input point clouds are re-sampled as voxels and dimensionality features of the voxels are determined by principal component analysis (PCA). Then voxel cells with the same dimensionality are clustered. Next, the Extended Gaussian Image (EGI) descriptor of those voxel clusters are constructed using significant eigenvectors of each voxel in the cluster. Correspondences between clusters in source and target data are obtained according to the similarity between their EGI descriptors. The random sampling consensus (RANSAC) algorithm is employed to remove outlying correspondences until a coarse alignment is obtained. If necessary, a fine registration is performed in a final step. This new method is illustrated on scan data sampling two indoor scenarios. The results of the tests are evaluated by computing the point to point distance between the two input point clouds. The presented two tests resulted in mean distances of 7.6 mm and 9.5 mm respectively, which are adequate for fine registration.

A coarse-to-fine scheme for groupwise registration of multisensor images

Directory of Open Access Journals (Sweden)

Yinghao Li

2016-11-01

Full Text Available Ensemble registration is concerned with a group of images that need to be registered simultaneously. It is challenging but important for many image analysis tasks such as vehicle detection and medical image fusion. To solve this problem effectively, a novel coarse-to-fine scheme for groupwise image registration is proposed. First, in the coarse registration step, unregistered images are divided into reference image set and float image set. The images of the two sets are registered based on segmented region matching. The coarse registration results are used as an initial solution for the next step. Then, in the fine registration step, a Gaussian mixture model with a local template is used to model the joint intensity of coarse-registered images. Meanwhile, a minimum message length criterion-based method is employed to determine the unknown number of mixing components. Based on this mixture model, a maximum likelihood framework is used to register a group of images. To evaluate the performance of the proposed approach, some representative groupwise registration approaches are compared on different image data sets. The experimental results show that the proposed approach has improved performance compared to conventional approaches.

Longitudinal, intermodality registration of quantitative breast PET and MRI data acquired before and during neoadjuvant chemotherapy: Preliminary results

International Nuclear Information System (INIS)

Atuegwu, Nkiruka C.; Williams, Jason M.; Li, Xia; Arlinghaus, Lori R.; Abramson, Richard G.; Chakravarthy, A. Bapsi; Abramson, Vandana G.; Yankeelov, Thomas E.

2014-01-01

Purpose: The authors propose a method whereby serially acquired DCE-MRI, DW-MRI, and FDG-PET breast data sets can be spatially and temporally coregistered to enable the comparison of changes in parameter maps at the voxel level. Methods: First, the authors aligned the PET and MR images at each time point rigidly and nonrigidly. To register the MR images longitudinally, the authors extended a nonrigid registration algorithm by including a tumor volume-preserving constraint in the cost function. After the PET images were aligned to the MR images at each time point, the authors then used the transformation obtained from the longitudinal registration of the MRI volumes to register the PET images longitudinally. The authors tested this approach on ten breast cancer patients by calculating a modified Dice similarity of tumor size between the PET and MR images as well as the bending energy and changes in the tumor volume after the application of the registration algorithm. Results: The median of the modified Dice in the registered PET and DCE-MRI data was 0.92. For the longitudinal registration, the median tumor volume change was −0.03% for the constrained algorithm, compared to −32.16% for the unconstrained registration algorithms (p = 8 × 10 −6 ). The medians of the bending energy were 0.0092 and 0.0001 for the unconstrained and constrained algorithms, respectively (p = 2.84 × 10 −7 ). Conclusions: The results indicate that the proposed method can accurately spatially align DCE-MRI, DW-MRI, and FDG-PET breast images acquired at different time points during therapy while preventing the tumor from being substantially distorted or compressed

Pesticide registration, distribution and use practices in Ghana

NARCIS (Netherlands)

Onwona Kwakye, Michael; Mengistie, Belay; Ofosu-Anim, John; Nuer, Alexander Tetteh K.; Den Brink, van Paul J.

2018-01-01

Ghana has implemented regulation on the registration, distribution and usage of pesticides in order to evaluate their environmental and human health effects. However, environmental monitoring and certified laboratories for pesticide analysis are lacking. Pesticide misuse, misapplication,

MO-C-17A-13: Uncertainty Evaluation of CT Image Deformable Registration for H and N Cancer Adaptive Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Qin, A; Yan, D [William Beaumont Hospital, Royal Oak, MI (United States)

2014-06-15

Purpose: To evaluate uncertainties of organ specific Deformable Image Registration (DIR) for H and N cancer Adaptive Radiation Therapy (ART). Methods: A commercial DIR evaluation tool, which includes a digital phantom library of 8 patients, and the corresponding “Ground truth Deformable Vector Field” (GT-DVF), was used in the study. Each patient in the phantom library includes the GT-DVF created from a pair of CT images acquired prior to and at the end of the treatment course. Five DIR tools, including 2 commercial tools (CMT1, CMT2), 2 in-house (IH-FFD1, IH-FFD2), and a classic DEMON algorithms, were applied on the patient images. The resulting DVF was compared to the GT-DVF voxel by voxel. Organ specific DVF uncertainty was calculated for 10 ROIs: Whole Body, Brain, Brain Stem, Cord, Lips, Mandible, Parotid, Esophagus and Submandibular Gland. Registration error-volume histogram was constructed for comparison. Results: The uncertainty is relatively small for brain stem, cord and lips, while large in parotid and submandibular gland. CMT1 achieved best overall accuracy (on whole body, mean vector error of 8 patients: 0.98±0.29 mm). For brain, mandible, parotid right, parotid left and submandibular glad, the classic Demon algorithm got the lowest uncertainty (0.49±0.09, 0.51±0.16, 0.46±0.11, 0.50±0.11 and 0.69±0.47 mm respectively). For brain stem, cord and lips, the DVF from CMT1 has the best accuracy (0.28±0.07, 0.22±0.08 and 0.27±0.12 mm respectively). All algorithms have largest right parotid uncertainty on patient #7, which has image artifact caused by tooth implantation. Conclusion: Uncertainty of deformable CT image registration highly depends on the registration algorithm, and organ specific. Large uncertainty most likely appears at the location of soft-tissue organs far from the bony structures. Among all 5 DIR methods, the classic DEMON and CMT1 seem to be the best to limit the uncertainty within 2mm for all OARs. Partially supported by

The hidden KPI registration accuracy.

Science.gov (United States)

Shorrosh, Paul

2011-09-01

Determining the registration accuracy rate is fundamental to improving revenue cycle key performance indicators. A registration quality assurance (QA) process allows errors to be corrected before bills are sent and helps registrars learn from their mistakes. Tools are available to help patient access staff who perform registration QA manually.

Alternative face models for 3D face registration

Science.gov (United States)

Salah, Albert Ali; Alyüz, Neşe; Akarun, Lale

2007-01-01

3D has become an important modality for face biometrics. The accuracy of a 3D face recognition system depends on a correct registration that aligns the facial surfaces and makes a comparison possible. The best results obtained so far use a one-to-all registration approach, which means each new facial surface is registered to all faces in the gallery, at a great computational cost. We explore the approach of registering the new facial surface to an average face model (AFM), which automatically establishes correspondence to the pre-registered gallery faces. Going one step further, we propose that using a couple of well-selected AFMs can trade-off computation time with accuracy. Drawing on cognitive justifications, we propose to employ category-specific alternative average face models for registration, which is shown to increase the accuracy of the subsequent recognition. We inspect thin-plate spline (TPS) and iterative closest point (ICP) based registration schemes under realistic assumptions on manual or automatic landmark detection prior to registration. We evaluate several approaches for the coarse initialization of ICP. We propose a new algorithm for constructing an AFM, and show that it works better than a recent approach. Finally, we perform simulations with multiple AFMs that correspond to different clusters in the face shape space and compare these with gender and morphology based groupings. We report our results on the FRGC 3D face database.

12 CFR 583.18 - Registrant.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Registrant. 583.18 Section 583.18 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY DEFINITIONS FOR REGULATIONS AFFECTING SAVINGS AND LOAN HOLDING COMPANIES § 583.18 Registrant. The term registrant means a savings and loan...

Registration and planning of radiotherapy and proton therapy treatment

International Nuclear Information System (INIS)

Bausse, Jerome

2010-01-01

Within the frame of an update and renewal project, the Orsay Proton Therapy Centre of the Curie Institute (IPCO) renews its software used for the treatment of patients by proton therapy, a radiotherapy technique which uses proton beams. High energies used in these treatments and the precision provided by proton particle characteristics require a more precise patient positioning than conventional radiotherapy: proton therapy requires a precision of about a millimetre. Thus, markers are placed on the skull which are generally well accepted by patients, but are a problem in the case of paediatric treatment, notably for the youngest children whose skull is still growing. The first objective of this research is thus to use only intrinsic information from X-ray images used when positioning the patient. A second objective is to make the new software (TPS Isogray) perfectly compatible with IPCO requirements by maintaining the strengths of the previous TPS (Treatment Planning System) and being prepared to the implementation of a new installation. After a presentation of the context and state of the art in radiotherapy and patient positioning, the author proposes an overview of 2D registration methods, presents a new method for 2x2D registration, and addresses the problem of 3D registration. Then, after a presentation of proton therapy, the author addresses different specific issues and aspects: the compensator (simulation, calculation, and tests), dose calculation, the 'Pencil-Beam' algorithm, tests, and introduced improvements [fr

The ANACONDA algorithm for deformable image registration in radiotherapy

International Nuclear Information System (INIS)

Weistrand, Ola; Svensson, Stina

2015-01-01

Purpose: The purpose of this work was to describe a versatile algorithm for deformable image registration with applications in radiotherapy and to validate it on thoracic 4DCT data as well as CT/cone beam CT (CBCT) data. Methods: ANAtomically CONstrained Deformation Algorithm (ANACONDA) combines image information (i.e., intensities) with anatomical information as provided by contoured image sets. The registration problem is formulated as a nonlinear optimization problem and solved with an in-house developed solver, tailored to this problem. The objective function, which is minimized during optimization, is a linear combination of four nonlinear terms: 1. image similarity term; 2. grid regularization term, which aims at keeping the deformed image grid smooth and invertible; 3. a shape based regularization term which works to keep the deformation anatomically reasonable when regions of interest are present in the reference image; and 4. a penalty term which is added to the optimization problem when controlling structures are used, aimed at deforming the selected structure in the reference image to the corresponding structure in the target image. Results: To validate ANACONDA, the authors have used 16 publically available thoracic 4DCT data sets for which target registration errors from several algorithms have been reported in the literature. On average for the 16 data sets, the target registration error is 1.17 ± 0.87 mm, Dice similarity coefficient is 0.98 for the two lungs, and image similarity, measured by the correlation coefficient, is 0.95. The authors have also validated ANACONDA using two pelvic cases and one head and neck case with planning CT and daily acquired CBCT. Each image has been contoured by a physician (radiation oncologist) or experienced radiation therapist. The results are an improvement with respect to rigid registration. However, for the head and neck case, the sample set is too small to show statistical significance. Conclusions: ANACONDA

77 FR 66920 - Registration of Claims to Copyright: Group Registration of Serial Issues Filed Electronically

Science.gov (United States)

2012-11-08

... registered on a single application and for a single fee. The group registration privilege is contingent upon... was limited to basic registrations, i.e., claims in single works, while the capacity to process online... of related serials. Revisions to the electronic registration system will upgrade the capacity of the...

Automatic registration using implicit shape representations: applications in intraoperative 3D rotational angiography to preoperative CTA registration

International Nuclear Information System (INIS)

Subramanian, Navneeth; Pichon, Eric; Solomon, Stephen B.

2009-01-01

A solution for automatic registration of 3D rotational angiography (XA) to CT/MR of the liver. Targeted for use in treatment planning of liver interventions. A shape-based approach to registration is proposed that does not require specification of landmarks nor is it prone to local minima like purely intensity-based registration methods. Through the use of vessel characteristics, accurate registration is possible even in the presence of deformations induced by catheters and respiratory motion. Registration was performed on eight pairs of multiphase CT angiography and 3D rotational digital angiography datasets. Quantitative validation of the registration accuracy using vessel landmarks was performed on these datasets. The validation study showed that the method has a registration error of 9.41±4.13 mm. In addition, the computation time is well below 60 s making it attractive for clinical application. A new method for fully automatic 3DXA to CT/MR image registration was developed and found to be efficient and accurate using clinically realistic datasets. (orig.)

Liberalisation and green patent registrations of electric utilities in Europe

International Nuclear Information System (INIS)

Salies, Evens; Nesta, Lionel

2010-10-01

The authors report a study of the influence of reforms which introduce a liberalisation of energy markets on the innovation behaviour of electric utilities in some countries. Within a context of concentration of this sector, the hypothesis of a negative impact on patent registration by electric utilities is tested by the authors. They first define the notion of environmental innovation and its evolution in the electric energy sector as the climate and environment issues are nowadays extremely important for the energy sector. R and D here addresses micro-generation, fuel cells, tidal turbine systems, energy production by using solar energy, and biomass gasification. They discuss numbers of pattern registrations by European utilities before and after laws on energy market reform. They present an econometric model and data used to test the hypothesis and comment the obtained results. The model comprises a knowledge production function, and various explicative variables (firm size and R and D, reforms, technological opportunities, energy mix, and influence of demand)

Evaluating Industry Payments Among Dermatology Clinical Practice Guidelines Authors.

Science.gov (United States)

Checketts, Jake X; Sims, Matthew Thomas; Vassar, Matt

2017-12-01

It is well documented that financial conflicts of interest influence medical research and clinical practice. Prior to the Open Payments provisions of the Affordable Care Act, financial ties became apparent only through self-disclosure. The nature of financial interests has not been studied among physicians who develop dermatology clinical practice guidelines. To evaluate payments received by physicians who author dermatology clinical practice guidelines, compare disclosure statements for accuracy, determine whether pharmaceutical companies from which the authors received payments manufactured products related to the guidelines, and examine the extent to which the American Academy of Dermatology enforced their Administrative Regulations for guideline development. Three American Academy of Dermatology guidelines published from 2013 to 2016 were retrieved. Double data extraction was used to record financial payments received by 49 guideline authors using the Open Payments database. Payments received by the authors from the date of the initial literature search to the date of publication were used to evaluate disclosure statement accuracy, detail the companies providing payments, and evaluate Administrative Regulations enforcement. This study is applicable to clinical practice guideline panels drafting recommendations, physicians using clinical practice guidelines to inform patient care, and those establishing policies for guideline development. Our main outcomes are the monetary values and types of payments received by physicians who author dermatology guidelines and the accuracy of disclosure statements. Data were collected from the Open Payments database and analyzed descriptively. Of the 49 authors evaluated, 40 received at least 1 reported industry payment, 31 accepted more than $1000, 25 accepted more than $10 000, and 18 accepted more than $50 000. Financial payments amounted to a mean of $157 177 per author. The total reimbursement among the 49 authors

Automated dental implantation using image-guided robotics: registration results.

Science.gov (United States)

Sun, Xiaoyan; McKenzie, Frederic D; Bawab, Sebastian; Li, Jiang; Yoon, Yongki; Huang, Jen-K

2011-09-01

One of the most important factors affecting the outcome of dental implantation is the accurate insertion of the implant into the patient's jaw bone, which requires a high degree of anatomical accuracy. With the accuracy and stability of robots, image-guided robotics is expected to provide more reliable and successful outcomes for dental implantation. Here, we proposed the use of a robot for drilling the implant site in preparation for the insertion of the implant. An image-guided robotic system for automated dental implantation is described in this paper. Patient-specific 3D models are reconstructed from preoperative Cone-beam CT images, and implantation planning is performed with these virtual models. A two-step registration procedure is applied to transform the preoperative plan of the implant insertion into intra-operative operations of the robot with the help of a Coordinate Measurement Machine (CMM). Experiments are carried out with a phantom that is generated from the patient-specific 3D model. Fiducial Registration Error (FRE) and Target Registration Error (TRE) values are calculated to evaluate the accuracy of the registration procedure. FRE values are less than 0.30 mm. Final TRE values after the two-step registration are 1.42 ± 0.70 mm (N = 5). The registration results of an automated dental implantation system using image-guided robotics are reported in this paper. Phantom experiments show that the practice of robot in the dental implantation is feasible and the system accuracy is comparable to other similar systems for dental implantation.

Increasing the automation of a 2D-3D registration system.

Science.gov (United States)

Varnavas, Andreas; Carrell, Tom; Penney, Graeme

2013-02-01

Routine clinical use of 2D-3D registration algorithms for Image Guided Surgery remains limited. A key aspect for routine clinical use of this technology is its degree of automation, i.e., the amount of necessary knowledgeable interaction between the clinicians and the registration system. Current image-based registration approaches usually require knowledgeable manual interaction during two stages: for initial pose estimation and for verification of produced results. We propose four novel techniques, particularly suited to vertebra-based registration systems, which can significantly automate both of the above stages. Two of these techniques are based upon the intraoperative "insertion" of a virtual fiducial marker into the preoperative data. The remaining two techniques use the final registration similarity value between multiple CT vertebrae and a single fluoroscopy vertebra. The proposed methods were evaluated with data from 31 operations (31 CT scans, 419 fluoroscopy images). Results show these methods can remove the need for manual vertebra identification during initial pose estimation, and were also very effective for result verification, producing a combined true positive rate of 100% and false positive rate equal to zero. This large decrease in required knowledgeable interaction is an important contribution aiming to enable more widespread use of 2D-3D registration technology.

Efficient nonrigid registration using ranked order statistics

DEFF Research Database (Denmark)

Tennakoon, Ruwan B.; Bab-Hadiashar, Alireza; de Bruijne, Marleen

2013-01-01

of research. In this paper we propose a fast and accurate non-rigid registration method for intra-modality volumetric images. Our approach exploits the information provided by an order statistics based segmentation method, to find the important regions for registration and use an appropriate sampling scheme......Non-rigid image registration techniques are widely used in medical imaging applications. Due to high computational complexities of these techniques, finding appropriate registration method to both reduce the computation burden and increase the registration accuracy has become an intense area...... to target those areas and reduce the registration computation time. A unique advantage of the proposed method is its ability to identify the point of diminishing returns and stop the registration process. Our experiments on registration of real lung CT images, with expert annotated landmarks, show...

Beating-heart registration for organ-mounted robots.

Science.gov (United States)

Wood, Nathan A; Schwartzman, David; Passineau, Michael J; Moraca, Robert J; Zenati, Marco A; Riviere, Cameron N

2018-03-06

Organ-mounted robots address the problem of beating-heart surgery by adhering to the heart, passively providing a platform that approaches zero relative motion. Because of the quasi-periodic deformation of the heart due to heartbeat and respiration, registration must address not only spatial registration but also temporal registration. Motion data were collected in the porcine model in vivo (N = 6). Fourier series models of heart motion were developed. By comparing registrations generated using an iterative closest-point approach at different phases of respiration, the phase corresponding to minimum registration distance is identified. The spatiotemporal registration technique presented here reduces registration error by an average of 4.2 mm over the 6 trials, in comparison with a more simplistic static registration that merely averages out the physiological motion. An empirical metric for spatiotemporal registration of organ-mounted robots is defined and demonstrated using data from animal models in vivo. Copyright © 2018 John Wiley & Sons, Ltd.

Interindividual registration and dose mapping for voxelwise population analysis of rectal toxicity in prostate cancer radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Dréan, Gaël; Acosta, Oscar, E-mail: Oscar.Acosta@univ-rennes1.fr; Simon, Antoine; Haigron, Pascal [INSERM, U1099, Rennes F-35000 (France); Université de Rennes 1, LTSI, Rennes F-35000 (France); Lafond, Caroline; Crevoisier, Renaud de [INSERM, U1099, Rennes F-35000 (France); Université de Rennes 1, LTSI, Rennes F-35000 (France); Département de Radiothérapie, Center Eugène Marquis, Rennes F-35000 (France)

2016-06-15

Purpose: Recent studies revealed a trend toward voxelwise population analysis in order to understand the local dose/toxicity relationships in prostate cancer radiotherapy. Such approaches require, however, an accurate interindividual mapping of the anatomies and 3D dose distributions toward a common coordinate system. This step is challenging due to the high interindividual variability. In this paper, the authors propose a method designed for interindividual nonrigid registration of the rectum and dose mapping for population analysis. Methods: The method is based on the computation of a normalized structural description of the rectum using a Laplacian-based model. This description takes advantage of the tubular structure of the rectum and its centerline to be embedded in a nonrigid registration-based scheme. The performances of the method were evaluated on 30 individuals treated for prostate cancer in a leave-one-out cross validation. Results: Performance was measured using classical metrics (Dice score and Hausdorff distance), along with new metrics devised to better assess dose mapping in relation with structural deformation (dose-organ overlap). Considering these scores, the proposed method outperforms intensity-based and distance maps-based registration methods. Conclusions: The proposed method allows for accurately mapping interindividual 3D dose distributions toward a single anatomical template, opening the way for further voxelwise statistical analysis.

Evaluation of interpolation effects on upsampling and accuracy of cost functions-based optimized automatic image registration.

Science.gov (United States)

Mahmoudzadeh, Amir Pasha; Kashou, Nasser H

2013-01-01

Interpolation has become a default operation in image processing and medical imaging and is one of the important factors in the success of an intensity-based registration method. Interpolation is needed if the fractional unit of motion is not matched and located on the high resolution (HR) grid. The purpose of this work is to present a systematic evaluation of eight standard interpolation techniques (trilinear, nearest neighbor, cubic Lagrangian, quintic Lagrangian, hepatic Lagrangian, windowed Sinc, B-spline 3rd order, and B-spline 4th order) and to compare the effect of cost functions (least squares (LS), normalized mutual information (NMI), normalized cross correlation (NCC), and correlation ratio (CR)) for optimized automatic image registration (OAIR) on 3D spoiled gradient recalled (SPGR) magnetic resonance images (MRI) of the brain acquired using a 3T GE MR scanner. Subsampling was performed in the axial, sagittal, and coronal directions to emulate three low resolution datasets. Afterwards, the low resolution datasets were upsampled using different interpolation methods, and they were then compared to the high resolution data. The mean squared error, peak signal to noise, joint entropy, and cost functions were computed for quantitative assessment of the method. Magnetic resonance image scans and joint histogram were used for qualitative assessment of the method.

Evaluation of Interpolation Effects on Upsampling and Accuracy of Cost Functions-Based Optimized Automatic Image Registration

Directory of Open Access Journals (Sweden)

Amir Pasha Mahmoudzadeh

2013-01-01

Full Text Available Interpolation has become a default operation in image processing and medical imaging and is one of the important factors in the success of an intensity-based registration method. Interpolation is needed if the fractional unit of motion is not matched and located on the high resolution (HR grid. The purpose of this work is to present a systematic evaluation of eight standard interpolation techniques (trilinear, nearest neighbor, cubic Lagrangian, quintic Lagrangian, hepatic Lagrangian, windowed Sinc, B-spline 3rd order, and B-spline 4th order and to compare the effect of cost functions (least squares (LS, normalized mutual information (NMI, normalized cross correlation (NCC, and correlation ratio (CR for optimized automatic image registration (OAIR on 3D spoiled gradient recalled (SPGR magnetic resonance images (MRI of the brain acquired using a 3T GE MR scanner. Subsampling was performed in the axial, sagittal, and coronal directions to emulate three low resolution datasets. Afterwards, the low resolution datasets were upsampled using different interpolation methods, and they were then compared to the high resolution data. The mean squared error, peak signal to noise, joint entropy, and cost functions were computed for quantitative assessment of the method. Magnetic resonance image scans and joint histogram were used for qualitative assessment of the method.

Automatic bone detection and soft tissue aware ultrasound-CT registration for computer-aided orthopedic surgery.

Science.gov (United States)

Wein, Wolfgang; Karamalis, Athanasios; Baumgartner, Adrian; Navab, Nassir

2015-06-01

The transfer of preoperative CT data into the tracking system coordinates within an operating room is of high interest for computer-aided orthopedic surgery. In this work, we introduce a solution for intra-operative ultrasound-CT registration of bones. We have developed methods for fully automatic real-time bone detection in ultrasound images and global automatic registration to CT. The bone detection algorithm uses a novel bone-specific feature descriptor and was thoroughly evaluated on both in-vivo and ex-vivo data. A global optimization strategy aligns the bone surface, followed by a soft tissue aware intensity-based registration to provide higher local registration accuracy. We evaluated the system on femur, tibia and fibula anatomy in a cadaver study with human legs, where magnetically tracked bone markers were implanted to yield ground truth information. An overall median system error of 3.7 mm was achieved on 11 datasets. Global and fully automatic registration of bones aquired with ultrasound to CT is feasible, with bone detection and tracking operating in real time for immediate feedback to the surgeon.

S-HAMMER: hierarchical attribute-guided, symmetric diffeomorphic registration for MR brain images.

Science.gov (United States)

Wu, Guorong; Kim, Minjeong; Wang, Qian; Shen, Dinggang

2014-03-01

Deformable registration has been widely used in neuroscience studies for spatial normalization of brain images onto the standard space. Because of possible large anatomical differences across different individual brains, registration performance could be limited when trying to estimate a single directed deformation pathway, i.e., either from template to subject or from subject to template. Symmetric image registration, however, offers an effective way to simultaneously deform template and subject images toward each other until they meet at the middle point. Although some intensity-based registration algorithms have nicely incorporated this concept of symmetric deformation, the pointwise intensity matching between two images may not necessarily imply the matching of correct anatomical correspondences. Based on HAMMER registration algorithm (Shen and Davatzikos, [2002]: IEEE Trans Med Imaging 21:1421-1439), we integrate the strategies of hierarchical attribute matching and symmetric diffeomorphic deformation to build a new symmetric-diffeomorphic HAMMER registration algorithm, called as S-HAMMER. The performance of S-HAMMER has been extensively compared with 14 state-of-the-art nonrigid registration algorithms evaluated in (Klein et al., [2009]: NeuroImage 46:786-802) by using real brain images in LPBA40, IBSR18, CUMC12, and MGH10 datasets. In addition, the registration performance of S-HAMMER, by comparison with other methods, is also demonstrated on both elderly MR brain images (>70 years old) and the simulated brain images with ground-truth deformation fields. In all experiments, our proposed method achieves the best registration performance over all other registration methods, indicating the high applicability of our method in future neuroscience and clinical applications. Copyright © 2013 Wiley Periodicals, Inc.

Use of articulated registration for response assessment of individual metastatic bone lesions

International Nuclear Information System (INIS)

Yip, Stephen; Jeraj, Robert

2014-01-01

Accurate skeleton registration is necessary to match corresponding metastatic bone lesions for response assessment over multiple scans. In articulated registration (ART), whole-body skeletons are registered by auto-segmenting individual bones, then rigidly aligning them. Performance and robustness of the ART in lesion matching were evaluated and compared to other commonly used registration techniques. Sixteen prostate cancer patients were treated either with molecular targeted therapy or chemotherapy. Ten out of the 16 patients underwent the double baseline whole-body [F-18]NaF PET/CT scans for test-retest (TRT) evaluation. Twelve of the 16 patients underwent pre- and mid-treatment [F-18]NaF PET/CT scans. Skeletons at different time points were registered using ART, rigid, and deformable (DR) registration algorithms. The corresponding lesions were contoured and identified on successive PET images based on including the voxels with the standardized uptake value over 15. Each algorithm was evaluated for its ability to accurately align corresponding lesions via skeleton registration. A lesion matching score (MS) was measured for each lesion, which quantified the per cent overlap between the lesion's two corresponding contours. Three separate sensitivity studies were conducted to investigate the robustness of ART in matching: sensitivity of lesion matching to various contouring threshold levels, effects of imperfections in the bone auto-segmentation and sensitivity of mis-registration. The performance of ART (MS = 82% for both datasets, p ≪ 0.001) in lesion matching was significantly better than rigid (MS TRT  = 53%, MS Response  = 46%) and DR (MS TRT  = 46%, MS Response  = 45%) algorithms. Neither varying threshold levels for lesion contouring nor imperfect bone segmentation had significant (p∼0.10) impact on the ART matching performance as the MS remained unchanged. Despite the mis-registration reduced MS for ART, as low as 67% (p ≪ 0.001), the

MO-AB-BRA-09: Temporally Realistic Manipulation a 4D Biomechanical Lung Phantom for Evaluation of Simultaneous Registration and Segmentation

Energy Technology Data Exchange (ETDEWEB)

Markel, D; Levesque, I R.; Larkin, J; Leger, P; El Naqa, I [McGill University, Montreal, QC (Canada)

2015-06-15

Purpose: To produce multi-modality compatible, realistic datasets for the joint evaluation of segmentation and registration with a reliable ground truth using a 4D biomechanical lung phantom. The further development of a computer controlled air flow system for recreation of real patient breathing patterns is incorporated for additional evaluation of motion prediction algorithms. Methods: A pair of preserved porcine lungs was pneumatically manipulated using an in-house computer controlled respirator. The respirator consisted of a set of bellows actuated by a 186 W computer controlled industrial motor. Patient breathing traces were recorded using a respiratory bellows belt during CT simulation and input into a control program incorporating a proportional-integral-derivative (PID) feedback controller in LabVIEW. Mock tumors were created using dual compartment vacuum sealed sea sponges. 65% iohexol,a gadolinium-based contrast agent and 18F-FDG were used to produce contrast and thus determine a segmentation ground truth. The intensity distributions of the compartments were then digitally matched for the final dataset. A bifurcation tracking pipeline provided a registration ground truth using the bronchi of the lung. The lungs were scanned using a GE Discovery-ST PET/CT scanner and a Phillips Panorama 0.23T MRI using a T1 weighted 3D fast field echo (FFE) protocol. Results: The standard deviation of the error between the patient breathing trace and the encoder feedback from the respirator was found to be ±4.2%. Bifurcation tracking error using CT (0.97×0.97×3.27 mm{sup 3} resolution) was found to be sub-voxel up to 7.8 cm displacement for human lungs and less than 1.32 voxel widths in any axis up to 2.3 cm for the porcine lungs. Conclusion: An MRI/PET/CT compatible anatomically and temporally realistic swine lung phantom was developed for the evaluation of simultaneous registration and segmentation algorithms. With the addition of custom software and mock tumors, the

Generation and evaluation of 3D digital casts of maxillary defects based on multisource data registration: A pilot clinical study.

Science.gov (United States)

Ye, Hongqiang; Ma, Qijun; Hou, Yuezhong; Li, Man; Zhou, Yongsheng

2017-12-01

Digital techniques are not clinically applied for 1-piece maxillary prostheses containing an obturator and removable partial denture retained by the remaining teeth because of the difficulty in obtaining sufficiently accurate 3-dimensional (3D) images. The purpose of this pilot clinical study was to generate 3D digital casts of maxillary defects, including the defective region and the maxillary dentition, based on multisource data registration and to evaluate their effectiveness. Twelve participants with maxillary defects were selected. The maxillofacial region was scanned with spiral computer tomography (CT), and the maxillary arch and palate were scanned using an intraoral optical scanner. The 3D images from the CT and intraoral scanner were registered and merged to form a 3D digital cast of the maxillary defect containing the anatomic structures needed for the maxillary prosthesis. This included the defect cavity, maxillary dentition, and palate. Traditional silicone impressions were also made, and stone casts were poured. The accuracy of the digital cast in comparison with that of the stone cast was evaluated by measuring the distance between 4 anatomic landmarks. Differences and consistencies were assessed using paired Student t tests and the intraclass correlation coefficient (ICC). In 3 participants, physical resin casts were produced by rapid prototyping from digital casts. Based on the resin casts, maxillary prostheses were fabricated by using conventional methods and then evaluated in the participants to assess the clinical applicability of the digital casts. Digital casts of the maxillary defects were generated and contained all the anatomic details needed for the maxillary prosthesis. Comparing the digital and stone casts, a paired Student t test indicated that differences in the linear distances between landmarks were not statistically significant (P>.05). High ICC values (0.977 to 0.998) for the interlandmark distances further indicated the high

A three-dimensional correlation method for registration of medical images in radiology

Energy Technology Data Exchange (ETDEWEB)

Georgiou, Michalakis; Sfakianakis, George N [Department of Radiology, University of Miami, Jackson Memorial Hospital, Miami, FL 33136 (United States); Nagel, Joachim H [Institute of Biomedical Engineering, University of Stuttgart, Stuttgart 70174 (Germany)

1999-12-31

The availability of methods to register multi-modality images in order to `fuse` them to correlate their information is increasingly becoming an important requirement for various diagnostic and therapeutic procedures. A variety of image registration methods have been developed but they remain limited to specific clinical applications. Assuming rigid body transformation, two images can be registered if their differences are calculated in terms of translation, rotation and scaling. This paper describes the development and testing of a new correlation based approach for three-dimensional image registration. First, the scaling factors introduced by the imaging devices are calculated and compensated for. Then, the two images become translation invariant by computing their three-dimensional Fourier magnitude spectra. Subsequently, spherical coordinate transformation is performed and then the three-dimensional rotation is computed using a novice approach referred to as {sup p}olar Shells{sup .} The method of polar shells maps the three angles of rotation into one rotation and two translations of a two-dimensional function and then proceeds to calculate them using appropriate transformations based on the Fourier invariance properties. A basic assumption in the method is that the three-dimensional rotation is constrained to one large and two relatively small angles. This assumption is generally satisfied in normal clinical settings. The new three-dimensional image registration method was tested with simulations using computer generated phantom data as well as actual clinical data. Performance analysis and accuracy evaluation of the method using computer simulations yielded errors in the sub-pixel range. (authors) 6 refs., 3 figs.

A three-dimensional correlation method for registration of medical images in radiology

International Nuclear Information System (INIS)

Georgiou, Michalakis; Sfakianakis, George N.; Nagel, Joachim H.

1998-01-01

The availability of methods to register multi-modality images in order to 'fuse' them to correlate their information is increasingly becoming an important requirement for various diagnostic and therapeutic procedures. A variety of image registration methods have been developed but they remain limited to specific clinical applications. Assuming rigid body transformation, two images can be registered if their differences are calculated in terms of translation, rotation and scaling. This paper describes the development and testing of a new correlation based approach for three-dimensional image registration. First, the scaling factors introduced by the imaging devices are calculated and compensated for. Then, the two images become translation invariant by computing their three-dimensional Fourier magnitude spectra. Subsequently, spherical coordinate transformation is performed and then the three-dimensional rotation is computed using a novice approach referred to as p olar Shells . The method of polar shells maps the three angles of rotation into one rotation and two translations of a two-dimensional function and then proceeds to calculate them using appropriate transformations based on the Fourier invariance properties. A basic assumption in the method is that the three-dimensional rotation is constrained to one large and two relatively small angles. This assumption is generally satisfied in normal clinical settings. The new three-dimensional image registration method was tested with simulations using computer generated phantom data as well as actual clinical data. Performance analysis and accuracy evaluation of the method using computer simulations yielded errors in the sub-pixel range. (authors)

77 FR 18705 - Discontinuance of Form CO in Registration Practices

Science.gov (United States)

2012-03-28

... issue, the author is a citizen or domiciliary of the United States, the work is a work for hire, the... LIBRARY OF CONGRESS Copyright Office 37 CFR Parts 201 and 202 [Docket No. 2011-8] Discontinuance of Form CO in Registration Practices AGENCY: Copyright Office, Library of Congress. ACTION: Final...

Fast and accurate registration of cranial CT images with A-mode ultrasound.

Science.gov (United States)

Fieten, Lorenz; Schmieder, Kirsten; Engelhardt, Martin; Pasalic, Lamija; Radermacher, Klaus; Heger, Stefan

2009-05-01

Within the CRANIO project, a navigation module based on preoperative computed tomography (CT) data was developed for Computer and Robot Assisted Neurosurgery. The approach followed for non-invasive user-interactive registration of cranial CT images with the physical operating space consists of surface-based registration following pre-registration based on anatomical landmarks. Surface-based registration relies on bone surface points digitized transcutaneously by means of an optically tracked A-mode ultrasound (US) probe. As probe alignment and thus bone surface point digitization may be time-consuming, we investigated how to obtain high registration accuracy despite inaccurate pre-registration and a limited number of digitized bone surface points. Furthermore, we aimed at efficient man-machine-interaction during the probe alignment process. Finally, we addressed the problem of registration plausibility estimation in our approach. We modified the Iterative Closest Point (ICP) algorithm, presented by Besl and McKay and frequently used for surface-based registration, such that it can escape from local minima of the cost function to be iteratively minimized. The random-based ICP (R-ICP) we developed is less influenced by the quality of the pre-registration as it can escape from local minima close to the starting point for iterative optimization in the 6D domain of rigid transformations. The R-ICP is also better suited to approximate the global minimum as it can escape from local minima in the vicinity of the global minimum, too. Furthermore, we developed both CT-less and CT-based probe alignment tools along with appropriate man-machine strategies for a more time-efficient palpation process. To improve registration reliability, we developed a simple plausibility test based on data readily available after registration. In a cadaver study, where we evaluated the R-ICP algorithm, the probe alignment tools, and the plausibility test, the R-ICP algorithm consistently

MRI and CBCT image registration of temporomandibular joint: a systematic review.

Science.gov (United States)

Al-Saleh, Mohammed A Q; Alsufyani, Noura A; Saltaji, Humam; Jaremko, Jacob L; Major, Paul W

2016-05-10

The purpose of the present review is to systematically and critically analyze the available literature regarding the importance, applicability, and practicality of (MRI), computerized tomography (CT) or cone-beam CT (CBCT) image registration for TMJ anatomy and assessment. A systematic search of 4 databases; MEDLINE, EMBASE, EBM reviews and Scopus, was conducted by 2 reviewers. An additional manual search of the bibliography was performed. All articles discussing the magnetic resonance imaging MRI and CT or CBCT image registration for temporomandibular joint (TMJ) visualization or assessment were included. Only 3 articles satisfied the inclusion criteria. All included articles were published within the last 7 years. Two articles described MRI to CT multimodality image registration as a complementary tool to visualize TMJ. Both articles used images of one patient only to introduce the complementary concept of MRI-CT fused image. One article assessed the reliability of using MRI-CBCT registration to evaluate the TMJ disc position and osseous pathology for 10 temporomandibular disorder (TMD) patients. There are very limited studies of MRI-CT/CBCT registration to reach a conclusion regarding its accuracy or clinical use in the temporomandibular joints.

40 CFR 164.21 - Contents of a denial of registration, notice of intent to cancel a registration, or notice of...

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2010-07-01

..., notice of intent to cancel a registration, or notice of intent to change a classification. 164.21 Section... denial of registration, notice of intent to cancel a registration, or notice of intent to change a classification. (a) Contents. The denial of registration or a notice of intent to cancel a registration or to...

Entropy-Based Block Processing for Satellite Image Registration

Directory of Open Access Journals (Sweden)

Ikhyun Lee

2012-11-01

Full Text Available Image registration is an important task in many computer vision applications such as fusion systems, 3D shape recovery and earth observation. Particularly, registering satellite images is challenging and time-consuming due to limited resources and large image size. In such scenario, state-of-the-art image registration methods such as scale-invariant feature transform (SIFT may not be suitable due to high processing time. In this paper, we propose an algorithm based on block processing via entropy to register satellite images. The performance of the proposed method is evaluated using different real images. The comparative analysis shows that it not only reduces the processing time but also enhances the accuracy.

Hospital Registration Process Reengineering Using Simulation Method

Directory of Open Access Journals (Sweden)

Qiang Su

2010-01-01

Full Text Available With increasing competition, many healthcare organizations have undergone tremendous reform in the last decade aiming to increase efficiency, decrease waste, and reshape the way that care is delivered. This study focuses on the operational efficiency improvement of hospital’s registration process. The operational efficiency related factors including the service process, queue strategy, and queue parameters were explored systematically and illustrated with a case study. Guided by the principle of business process reengineering (BPR, a simulation approach was employed for process redesign and performance optimization. As a result, the queue strategy is changed from multiple queues and multiple servers to single queue and multiple servers with a prepare queue. Furthermore, through a series of simulation experiments, the length of the prepare queue and the corresponding registration process efficiency was quantitatively evaluated and optimized.

Automatic registration method for multisensor datasets adopted for dimensional measurements on cutting tools

International Nuclear Information System (INIS)

Shaw, L; Mehari, F; Weckenmann, A; Ettl, S; Häusler, G

2013-01-01

Multisensor systems with optical 3D sensors are frequently employed to capture complete surface information by measuring workpieces from different views. During coarse and fine registration the resulting datasets are afterward transformed into one common coordinate system. Automatic fine registration methods are well established in dimensional metrology, whereas there is a deficit in automatic coarse registration methods. The advantage of a fully automatic registration procedure is twofold: it enables a fast and contact-free alignment and further a flexible application to datasets of any kind of optical 3D sensor. In this paper, an algorithm adapted for a robust automatic coarse registration is presented. The method was originally developed for the field of object reconstruction or localization. It is based on a segmentation of planes in the datasets to calculate the transformation parameters. The rotation is defined by the normals of three corresponding segmented planes of two overlapping datasets, while the translation is calculated via the intersection point of the segmented planes. First results have shown that the translation is strongly shape dependent: 3D data of objects with non-orthogonal planar flanks cannot be registered with the current method. In the novel supplement for the algorithm, the translation is additionally calculated via the distance between centroids of corresponding segmented planes, which results in more than one option for the transformation. A newly introduced measure considering the distance between the datasets after coarse registration evaluates the best possible transformation. Results of the robust automatic registration method are presented on the example of datasets taken from a cutting tool with a fringe-projection system and a focus-variation system. The successful application in dimensional metrology is proven with evaluations of shape parameters based on the registered datasets of a calibrated workpiece. (paper)

Image registration with auto-mapped control volumes

International Nuclear Information System (INIS)

Schreibmann, Eduard; Xing Lei

2006-01-01

Many image registration algorithms rely on the use of homologous control points on the two input image sets to be registered. In reality, the interactive identification of the control points on both images is tedious, difficult, and often a source of error. We propose a two-step algorithm to automatically identify homologous regions that are used as a priori information during the image registration procedure. First, a number of small control volumes having distinct anatomical features are identified on the model image in a somewhat arbitrary fashion. Instead of attempting to find their correspondences in the reference image through user interaction, in the proposed method, each of the control regions is mapped to the corresponding part of the reference image by using an automated image registration algorithm. A normalized cross-correlation (NCC) function or mutual information was used as the auto-mapping metric and a limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm (L-BFGS) was employed to optimize the function to find the optimal mapping. For rigid registration, the transformation parameters of the system are obtained by averaging that derived from the individual control volumes. In our deformable calculation, the mapped control volumes are treated as the nodes or control points with known positions on the two images. If the number of control volumes is not enough to cover the whole image to be registered, additional nodes are placed on the model image and then located on the reference image in a manner similar to the conventional BSpline deformable calculation. For deformable registration, the established correspondence by the auto-mapped control volumes provides valuable guidance for the registration calculation and greatly reduces the dimensionality of the problem. The performance of the two-step registrations was applied to three rigid registration cases (two PET-CT registrations and a brain MRI-CT registration) and one deformable registration of

Rigid 3D-3D registration of TOF MRA integrating vessel segmentation for quantification of recurrence volumes after coiling cerebral aneurysm

International Nuclear Information System (INIS)

Saering, Dennis; Forkert, Nils Daniel; Fiehler, Jens; Ries, Thorsten

2012-01-01

A fast and reproducible quantification of the recurrence volume of coiled aneurysms is required to enable a more timely evaluation of new coils. This paper presents two registration schemes for the semi-automatic quantification of aneurysm recurrence volumes based on baseline and follow-up 3D MRA TOF datasets. The quantification of shape changes requires a previous definition of corresponding structures in both datasets. For this, two different rigid registration methods have been developed and evaluated. Besides a state-of-the-art rigid registration method, a second approach integrating vessel segmentations is presented. After registration, the aneurysm recurrence volume can be calculated based on the difference image. The computed volumes were compared to manually extracted volumes. An evaluation based on 20 TOF MRA datasets (baseline and follow-up) of ten patients showed that both registration schemes are generally capable of providing sufficient registration results. Regarding the quantification of aneurysm recurrence volumes, the results suggest that the second segmentation-based registration method yields better results, while a reduction of the computation and interaction time is achieved at the same time. The proposed registration scheme incorporating vessel segmentation enables an improved quantification of recurrence volumes of coiled aneurysms with reduced computation and interaction time. (orig.)

Size variation and collapse of emphysema holes at inspiration and expiration CT scan: evaluation with modified length scale method and image co-registration.

Science.gov (United States)

Oh, Sang Young; Lee, Minho; Seo, Joon Beom; Kim, Namkug; Lee, Sang Min; Lee, Jae Seung; Oh, Yeon Mok

2017-01-01

A novel approach of size-based emphysema clustering has been developed, and the size variation and collapse of holes in emphysema clusters are evaluated at inspiratory and expiratory computed tomography (CT). Thirty patients were visually evaluated for the size-based emphysema clustering technique and a total of 72 patients were evaluated for analyzing collapse of the emphysema hole in this study. A new approach for the size differentiation of emphysema holes was developed using the length scale, Gaussian low-pass filtering, and iteration approach. Then, the volumetric CT results of the emphysema patients were analyzed using the new method, and deformable registration was carried out between inspiratory and expiratory CT. Blind visual evaluations of EI by two readers had significant correlations with the classification using the size-based emphysema clustering method ( r -values of reader 1: 0.186, 0.890, 0.915, and 0.941; reader 2: 0.540, 0.667, 0.919, and 0.942). The results of collapse of emphysema holes using deformable registration were compared with the pulmonary function test (PFT) parameters using the Pearson's correlation test. The mean extents of low-attenuation area (LAA), E1 (holes may be useful for understanding the dynamic collapse of emphysema and its functional relation.

46 CFR 402.220 - Registration of pilots.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Registration of pilots. 402.220 Section 402.220 Shipping... ORDERS Registration of Pilots § 402.220 Registration of pilots. (a) Each applicant pilot must complete the number of round trips specified in this section prior to registration as a U.S. registered pilot...

MRI-based treatment planning with pseudo CT generated through atlas registration.

Science.gov (United States)

Uh, Jinsoo; Merchant, Thomas E; Li, Yimei; Li, Xingyu; Hua, Chiaho

2014-05-01

To evaluate the feasibility and accuracy of magnetic resonance imaging (MRI)-based treatment planning using pseudo CTs generated through atlas registration. A pseudo CT, providing electron density information for dose calculation, was generated by deforming atlas CT images previously acquired on other patients. The authors tested 4 schemes of synthesizing a pseudo CT from single or multiple deformed atlas images: use of a single arbitrarily selected atlas, arithmetic mean process using 6 atlases, and pattern recognition with Gaussian process (PRGP) using 6 or 12 atlases. The required deformation for atlas CT images was derived from a nonlinear registration of conjugated atlas MR images to that of the patient of interest. The contrasts of atlas MR images were adjusted by histogram matching to reduce the effect of different sets of acquisition parameters. For comparison, the authors also tested a simple scheme assigning the Hounsfield unit of water to the entire patient volume. All pseudo CT generating schemes were applied to 14 patients with common pediatric brain tumors. The image similarity of real patient-specific CT and pseudo CTs constructed by different schemes was compared. Differences in computation times were also calculated. The real CT in the treatment planning system was replaced with the pseudo CT, and the dose distribution was recalculated to determine the difference. The atlas approach generally performed better than assigning a bulk CT number to the entire patient volume. Comparing atlas-based schemes, those using multiple atlases outperformed the single atlas scheme. For multiple atlas schemes, the pseudo CTs were similar to the real CTs (correlation coefficient, 0.787-0.819). The calculated dose distribution was in close agreement with the original dose. Nearly the entire patient volume (98.3%-98.7%) satisfied the criteria of chi-evaluation (pediatric brain tumor patients. The doses calculated from pseudo CTs agreed well with those from real CTs

A novel 3D volumetric voxel registration technique for volume-view-guided image registration of multiple imaging modalities

International Nuclear Information System (INIS)

Li Guang; Xie Huchen; Ning, Holly; Capala, Jacek; Arora, Barbara C.; Coleman, C. Norman; Camphausen, Kevin; Miller, Robert W.

2005-01-01

Purpose: To provide more clinically useful image registration with improved accuracy and reduced time, a novel technique of three-dimensional (3D) volumetric voxel registration of multimodality images is developed. Methods and Materials: This technique can register up to four concurrent images from multimodalities with volume view guidance. Various visualization effects can be applied, facilitating global and internal voxel registration. Fourteen computed tomography/magnetic resonance (CT/MR) image sets and two computed tomography/positron emission tomography (CT/PET) image sets are used. For comparison, an automatic registration technique using maximization of mutual information (MMI) and a three-orthogonal-planar (3P) registration technique are used. Results: Visually sensitive registration criteria for CT/MR and CT/PET have been established, including the homogeneity of color distribution. Based on the registration results of 14 CT/MR images, the 3D voxel technique is in excellent agreement with the automatic MMI technique and is indicatory of a global positioning error (defined as the means and standard deviations of the error distribution) using the 3P pixel technique: 1.8 deg ± 1.2 deg in rotation and 2.0 ± 1.3 (voxel unit) in translation. To the best of our knowledge, this is the first time that such positioning error has been addressed. Conclusion: This novel 3D voxel technique establishes volume-view-guided image registration of up to four modalities. It improves registration accuracy with reduced time, compared with the 3P pixel technique. This article suggests that any interactive and automatic registration should be safeguarded using the 3D voxel technique

Registration of clinical volumes to beams-eye-view images for real-time tracking

Energy Technology Data Exchange (ETDEWEB)

Bryant, Jonathan H.; Rottmann, Joerg; Lewis, John H.; Mishra, Pankaj; Berbeco, Ross I., E-mail: rberbeco@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, New South Wales 2006 (Australia)

2014-12-15

Purpose: The authors combine the registration of 2D beam’s eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). Methods: During treatment of lung SBRT cases, BEV images were continuously acquired with an electronic portal imaging device (EPID) operating in cine mode. For absolute registration of physician-defined volumes, an intensity based 2D/3D registration to the planning CT was performed using the end-of-exhale (EoE) phase of the four dimensional computed tomography (4DCT). The volume was converted from Hounsfield units into electron density by a calibration curve and digitally reconstructed radiographs (DRRs) were generated for each beam geometry. Using normalized cross correlation between the DRR and an EoE BEV image, the best in-plane rigid transformation was found. The transformation was applied to physician-defined contours in the planning CT, mapping them into the EPID image domain. A robust multiregion method of relative markerless lung tumor tracking quantified deviations from the EoE position. Results: The success of 2D/3D registration was demonstrated at the EoE breathing phase. By registering at this phase and then employing a separate technique for relative tracking, the authors are able to successfully track target volumes in the BEV images throughout the entire treatment delivery. Conclusions: Through the combination of EPID/4DCT registration and relative tracking, a necessary step toward the clinical implementation of BEV tracking has been completed. The knowledge of tumor volumes relative to the treatment field is important for future applications like real-time motion management, adaptive radiotherapy, and delivered dose calculations.

Spherical Demons: Fast Surface Registration

Science.gov (United States)

Yeo, B.T. Thomas; Sabuncu, Mert; Vercauteren, Tom; Ayache, Nicholas; Fischl, Bruce; Golland, Polina

2009-01-01

We present the fast Spherical Demons algorithm for registering two spherical images. By exploiting spherical vector spline interpolation theory, we show that a large class of regularizers for the modified demons objective function can be efficiently implemented on the sphere using convolution. Based on the one parameter subgroups of diffeomorphisms, the resulting registration is diffeomorphic and fast – registration of two cortical mesh models with more than 100k nodes takes less than 5 minutes, comparable to the fastest surface registration algorithms. Moreover, the accuracy of our method compares favorably to the popular FreeSurfer registration algorithm. We validate the technique in two different settings: (1) parcellation in a set of in-vivo cortical surfaces and (2) Brodmann area localization in ex-vivo cortical surfaces. PMID:18979813

32 CFR 634.19 - Registration policy.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Registration policy. 634.19 Section 634.19 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Motor Vehicle Registration § 634.19 Registration policy. (a) Motor vehicles will be...

Computed tomography lung iodine contrast mapping by image registration and subtraction

Science.gov (United States)

Goatman, Keith; Plakas, Costas; Schuijf, Joanne; Beveridge, Erin; Prokop, Mathias

2014-03-01

Pulmonary embolism (PE) is a relatively common and potentially life threatening disease, affecting around 600,000 people annually in the United States alone. Prompt treatment using anticoagulants is effective and saves lives, but unnecessary treatment risks life threatening haemorrhage. The specificity of any diagnostic test for PE is therefore as important as its sensitivity. Computed tomography (CT) angiography is routinely used to diagnose PE. However, there are concerns it may over-report the condition. Additional information about the severity of an occlusion can be obtained from an iodine contrast map that represents tissue perfusion. Such maps tend to be derived from dual-energy CT acquisitions. However, they may also be calculated by subtracting pre- and post-contrast CT scans. Indeed, there are technical advantages to such a subtraction approach, including better contrast-to-noise ratio for the same radiation dose, and bone suppression. However, subtraction relies on accurate image registration. This paper presents a framework for the automatic alignment of pre- and post-contrast lung volumes prior to subtraction. The registration accuracy is evaluated for seven subjects for whom pre- and post-contrast helical CT scans were acquired using a Toshiba Aquilion ONE scanner. One hundred corresponding points were annotated on the pre- and post-contrast scans, distributed throughout the lung volume. Surface-to-surface error distances were also calculated from lung segmentations. Prior to registration the mean Euclidean landmark alignment error was 2.57mm (range 1.43-4.34 mm), and following registration the mean error was 0.54mm (range 0.44-0.64 mm). The mean surface error distance was 1.89mm before registration and 0.47mm after registration. There was a commensurate reduction in visual artefacts following registration. In conclusion, a framework for pre- and post-contrast lung registration has been developed that is sufficiently accurate for lung subtraction

The cost of entry: An analysis of pharmaceutical registration fees in low-, middle-, and high-income countries.

Directory of Open Access Journals (Sweden)

Steven G Morgan

Full Text Available Advances in pharmaceuticals offer improved health outcomes for a wide range of illnesses, yet medicines are often inaccessible for many patients worldwide. One potential barrier to making medicines available to all is the cost of product registration, the fees for regulatory review and licensing for the sale of medicines beyond the cost of clinical trials, if needed.We performed a cross-sectional analysis of pharmaceutical registration fees in low-, middle-, and high-income countries. We collected data on market authorization fees for new chemical entities and for generic drugs in 95 countries. We calculated measures of registration fee size relative to population, gross domestic product (GDP, and total health spending in each country. Each of the 95 countries had a fee for registering new chemical entities. On average, the ratio of registration fees to GDP was highest in Europe and North America and lowest in South and Central America. Across individual countries, the level of registration fees was positively correlated with GDP and total health spending, with relatively few outliers.We find that, generally speaking, the regulatory fees charged by medicines regulatory authorities are roughly proportional to the market size in their jurisdictions. The data therefore do not support the hypothesis that regulatory fees are a barrier to market entry in most countries.

Do Tumors in the Lung Deform During Normal Respiration? An Image Registration Investigation

International Nuclear Information System (INIS)

Wu Jianzhou; Lei Peng; Shekhar, Raj; Li Huiling; Suntharalingam, Mohan; D'Souza, Warren D.

2009-01-01

Purpose: The purpose of this study was to investigate whether lung tumors may be described adequately using a rigid body assumption or whether they deform during normal respiration. Methods and Materials: Thirty patients with early stage non-small-cell lung cancer underwent four-dimensional (4D) computed tomography (CT) simulation. The gross tumor volume (GTV) was delineated on the 4D CT images. Image registration was performed in the vicinity of the GTV. The volume of interest for registration was the GTV and minimal volume of surrounding non-GTV tissue. Three types of registration were performed: translation only, translation + rotation, and deformable. The GTV contour from end-inhale was mapped to end-exhale using the registration-derived transformation field. The results were evaluated using three metrics: overlap index (OI), root-mean-squared distance (RMS), and Hausdorff distance (HD). Results: After translation only image registration, on average OI increased by 21.3%, RMS and HD reduced by 1.2 mm and 2.0 mm, respectively. The succeeding increases in OI after translation + rotation and deformable registration were 1.1% and 1.4% respectively. The succeeding reductions in RMS were 0.1 mm and 0.2 mm respectively. No reduction in HD was observed after translation + rotation and deformable image registration compared with translation only registration. The difference in the results from the three registration scenarios was independent of GTV size and motion amplitude. Conclusions: The primary effect of normal respiration on lung tumors was the translation of tumors. Rotation and deformation of lung tumors was determined to be minimal.

A block matching-based registration algorithm for localization of locally advanced lung tumors

Energy Technology Data Exchange (ETDEWEB)

Robertson, Scott P.; Weiss, Elisabeth; Hugo, Geoffrey D., E-mail: gdhugo@vcu.edu [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia, 23298 (United States)

2014-04-15

Purpose: To implement and evaluate a block matching-based registration (BMR) algorithm for locally advanced lung tumor localization during image-guided radiotherapy. Methods: Small (1 cm{sup 3}), nonoverlapping image subvolumes (“blocks”) were automatically identified on the planning image to cover the tumor surface using a measure of the local intensity gradient. Blocks were independently and automatically registered to the on-treatment image using a rigid transform. To improve speed and robustness, registrations were performed iteratively from coarse to fine image resolution. At each resolution, all block displacements having a near-maximum similarity score were stored. From this list, a single displacement vector for each block was iteratively selected which maximized the consistency of displacement vectors across immediately neighboring blocks. These selected displacements were regularized using a median filter before proceeding to registrations at finer image resolutions. After evaluating all image resolutions, the global rigid transform of the on-treatment image was computed using a Procrustes analysis, providing the couch shift for patient setup correction. This algorithm was evaluated for 18 locally advanced lung cancer patients, each with 4–7 weekly on-treatment computed tomography scans having physician-delineated gross tumor volumes. Volume overlap (VO) and border displacement errors (BDE) were calculated relative to the nominal physician-identified targets to establish residual error after registration. Results: Implementation of multiresolution registration improved block matching accuracy by 39% compared to registration using only the full resolution images. By also considering multiple potential displacements per block, initial errors were reduced by 65%. Using the final implementation of the BMR algorithm, VO was significantly improved from 77% ± 21% (range: 0%–100%) in the initial bony alignment to 91% ± 8% (range: 56%–100%;p < 0

A block matching-based registration algorithm for localization of locally advanced lung tumors

International Nuclear Information System (INIS)

Robertson, Scott P.; Weiss, Elisabeth; Hugo, Geoffrey D.

2014-01-01

Purpose: To implement and evaluate a block matching-based registration (BMR) algorithm for locally advanced lung tumor localization during image-guided radiotherapy. Methods: Small (1 cm 3 ), nonoverlapping image subvolumes (“blocks”) were automatically identified on the planning image to cover the tumor surface using a measure of the local intensity gradient. Blocks were independently and automatically registered to the on-treatment image using a rigid transform. To improve speed and robustness, registrations were performed iteratively from coarse to fine image resolution. At each resolution, all block displacements having a near-maximum similarity score were stored. From this list, a single displacement vector for each block was iteratively selected which maximized the consistency of displacement vectors across immediately neighboring blocks. These selected displacements were regularized using a median filter before proceeding to registrations at finer image resolutions. After evaluating all image resolutions, the global rigid transform of the on-treatment image was computed using a Procrustes analysis, providing the couch shift for patient setup correction. This algorithm was evaluated for 18 locally advanced lung cancer patients, each with 4–7 weekly on-treatment computed tomography scans having physician-delineated gross tumor volumes. Volume overlap (VO) and border displacement errors (BDE) were calculated relative to the nominal physician-identified targets to establish residual error after registration. Results: Implementation of multiresolution registration improved block matching accuracy by 39% compared to registration using only the full resolution images. By also considering multiple potential displacements per block, initial errors were reduced by 65%. Using the final implementation of the BMR algorithm, VO was significantly improved from 77% ± 21% (range: 0%–100%) in the initial bony alignment to 91% ± 8% (range: 56%–100%;p < 0.001). Left

SU-E-J-222: Evaluation of Deformable Registration of PET/CT Images for Cervical Cancer Brachytherapy

International Nuclear Information System (INIS)

Liao, Y; Turian, J; Templeton, A; Kiel, K; Chu, J; Kadir, T

2014-01-01

Purpose: PET/CT provides important functional information for radiotherapy targeting of cervical cancer. However, repeated PET/CT procedures for external beam and subsequent brachytherapy expose patients to additional radiation and are not cost effective. Our goal is to investigate the possibility of propagating PET-active volumes for brachytherapy procedures through deformable image registration (DIR) of earlier PET/CT and ultimately to minimize the number of PET/CT image sessions required. Methods: Nine cervical cancer patients each received their brachytherapy preplanning PET/CT at the end of EBRT with a Syed template in place. The planning PET/CT was acquired on the day of brachytherapy treatment with the actual applicator (Syed or Tandem and Ring) and rigidly registered. The PET/CT images were then deformably registered creating a third (deformed) image set for target prediction. Regions of interest with standardized uptake values (SUV) greater than 65% of maximum SUV were contoured as target volumes in all three sets of PET images. The predictive value of the registered images was evaluated by comparing the preplanning and deformed PET volumes with the planning PET volume using Dice's coefficient (DC) and center-of-mass (COM) displacement. Results: The average DCs were 0.12±0.14 and 0.19±0.16 for rigid and deformable predicted target volumes, respectively. The average COM displacements were 1.9±0.9 cm and 1.7±0.7 cm for rigid and deformable registration, respectively. The DCs were improved by deformable registration, however, both were lower than published data for DIR in other modalities and clinical sites. Anatomical changes caused by different brachytherapy applicators could have posed a challenge to the DIR algorithm. The physiological change from interstitial needle placement may also contribute to lower DC. Conclusion: The clinical use of DIR in PET/CT for cervical cancer brachytherapy appears to be limited by applicator choice and requires further

SU-F-J-84: Comparison of Quantitative Deformable Image Registration Evaluation Tools: Application to Prostate IGART

Energy Technology Data Exchange (ETDEWEB)

Dogan, N [University of Miami, Miami, FL (United States); Weiss, E [Virginia Commonwealth University, Richmond, Virginia (United States); Sleeman, W; Williamson, J [Virginia Commonwealth University, Richmond, VA (United States); Christensen, G [University of Iowa, Iowa City, IA (United States); Ford, J [University of Miami Miller School of Medicine, Miami, FL (United States)

2016-06-15

Purpose: Errors in displacement vector fields (DVFs) generated by Deformable Image Registration (DIR) algorithms can give rise to significant uncertainties in contour propagation and dose accumulation in Image-Guided Adaptive Radiotherapy (IGART). The purpose of this work is to assess the accuracy of two DIR algorithms using a variety of quality metrics for prostate IGART. Methods: Pelvic CT images were selected from an anonymized database of nineteen prostate patients who underwent 8–12 serial scans during radiotherapy. Prostate, bladder, and rectum were contoured on 34 image-sets for three patients by the same physician. The planning CT was deformably-registered to daily CT using three variants of the Small deformation Inverse Consistent Linear Elastic (SICLE) algorithm: Grayscale-driven (G), Contour-driven (C, which utilizes segmented structures to drive DIR), combined (G+C); and also grayscale ITK demons (Gd). The accuracy of G, C, G+C SICLE and Gd registrations were evaluated using a new metric Edge Gradient Distance to Agreement (EGDTA) and other commonly-used metrics such as Pearson Correlation Coefficient (PCC), Dice Similarity Index (DSI) and Hausdorff Distance (HD). Results: C and G+C demonstrated much better performance at organ boundaries, revealing the lowest HD and highest DSI, in prostate, bladder and rectum. G+C demonstrated the lowest mean EGDTA (1.14 mm), which corresponds to highest registration quality, compared to G and C DVFs (1.16 and 2.34 mm). However, demons DIR showed the best overall performance, revealing lowest EGDTA (0.73 mm) and highest PCC (0.85). Conclusion: As expected, both C- and C+G SICLE more accurately reproduce manually-contoured target datasets than G-SICLE or Gd using HD and DSI metrics. In general, the Gd appears to have difficulty reproducing large daily position and shape changes in the rectum and bladder. However, Gd outperforms SICLE in terms of EGDTA and PCC metrics, possibly at the expense of topological quality of

Complexities of policy-driven pre-registration nursing curricula.

Science.gov (United States)

McCarthy, Jilian; Holt, Maxine

This article discusses the challenges faced by two nurse educators when incorporating current health policy into a new pre-registration nursing curriculum, using public health and e-learning as examples. The article, which features the results of preliminary work from the authors' doctoral studies, includes summaries of students' discourses about e-learning and public health and how these subject areas are perceived by learners. Practical solutions to the challenges encountered are suggested.

Registration of pencil beam proton radiography data with X-ray CT.

Science.gov (United States)

Deffet, Sylvain; Macq, Benoît; Righetto, Roberto; Vander Stappen, François; Farace, Paolo

2017-10-01

Proton radiography seems to be a promising tool for assessing the quality of the stopping power computation in proton therapy. However, range error maps obtained on the basis of proton radiographs are very sensitive to small misalignment between the planning CT and the proton radiography acquisitions. In order to be able to mitigate misalignment in postprocessing, the authors implemented a fast method for registration between pencil proton radiography data obtained with a multilayer ionization chamber (MLIC) and an X-ray CT acquired on a head phantom. The registration was performed by optimizing a cost function which performs a comparison between the acquired data and simulated integral depth-dose curves. Two methodologies were considered, one based on dual orthogonal projections and the other one on a single projection. For each methodology, the robustness of the registration algorithm with respect to three confounding factors (measurement noise, CT calibration errors, and spot spacing) was investigated by testing the accuracy of the method through simulations based on a CT scan of a head phantom. The present registration method showed robust convergence towards the optimal solution. For the level of measurement noise and the uncertainty in the stopping power computation expected in proton radiography using a MLIC, the accuracy appeared to be better than 0.3° for angles and 0.3 mm for translations by use of the appropriate cost function. The spot spacing analysis showed that a spacing larger than the 5 mm used by other authors for the investigation of a MLIC for proton radiography led to results with absolute accuracy better than 0.3° for angles and 1 mm for translations when orthogonal proton radiographs were fed into the algorithm. In the case of a single projection, 6 mm was the largest spot spacing presenting an acceptable registration accuracy. For registration of proton radiography data with X-ray CT, the use of a direct ray-tracing algorithm to compute

The First 500 Registrations to the Research Registry®: Advancing Registration of Under-registered Study Types

Directory of Open Access Journals (Sweden)

Riaz Agha

2016-09-01

Full Text Available The Declaration of Helsinki 2013 encourages the registration of all research studies involving human participants. However, emphasis has been placed on prospective clinical trials, and it is estimated that only 10% of observational studies are registered. In response, Research Registry® was launched in February 2015; a retrospectively curated registry that is free and easy to use. Research Registry® enables prospective or retrospective registration of studies, including those study types that cannot be registered on existing registries. In this study, we describe the first 500 registrations on Research Registry®.Since the launch of Research Registry® in February 2015, data of registrations have been collected, including type of studies registered, country of origin and data curation activity. Inappropriate registrations, such as duplicates, were identified by the data curation process. These were removed from the database or modified as required. A quality score was assigned for each registration, based on Bradford-Hill’s criteria on what research studies should convey. Changes in quality scores over time were assessed. 500 studies were registered on Research Registry® from February 2015 to October 2015, with a total of 1.7 million patients enrolled. The most common study types were retrospective cohort studies (37.2%, case series (14.8% and first-in-man case reports (10.4%. Registrations were received from 57 different countries; the most submissions were received from Turkey, followed by China and the United Kingdom. Retrospective data curation identified 80 studies that were initially registered as the incorrect study type, and were subsequently correct. The Kruskal-Wallis test identified a significant improvement in quality scores for registrations from February 2015 to October 2015 (p < 0.0001.Since its conception in February 2015, Research Registry® has established itself as a new registry that is free, easy to use and enables the

The First 500 Registrations to the Research Registry®: Advancing Registration of Under-Registered Study Types.

Science.gov (United States)

Agha, Riaz; Fowler, Alexander J; Limb, Christopher; Al Omran, Yasser; Sagoo, Harkiran; Koshy, Kiron; Jafree, Daniyal J; Anwar, Mohammed Omer; McCullogh, Peter; Orgill, Dennis Paul

2016-01-01

The Declaration of Helsinki 2013 encourages the registration of all research studies involving human participants. However, emphasis has been placed on prospective clinical trials, and it is estimated that only 10% of observational studies are registered. In response, Research Registry ® was launched in February 2015; a retrospectively curated registry that is free and easy to use. Research Registry ® enables prospective or retrospective registration of studies, including those study types that cannot be registered on existing registries. In this study, we describe the first 500 registrations on Research Registry ® . Since the launch of Research Registry ® in February 2015, data of registrations have been collected, including type of studies registered, country of origin, and data curation activity. Inappropriate registrations, such as duplicates, were identified by the data curation process. These were removed from the database or modified as required. A quality score was assigned for each registration, based on Sir Austin Bradford Hill's criteria on what research studies should convey. Changes in quality scores over time were assessed. A total of 500 studies were registered on Research Registry ® from February 2015 to October 2015, with a total of 1.7 million patients enrolled. The most common study types were retrospective cohort studies (37.2%), case series (14.8%), and first-in-man case reports (10.4%). Registrations were received from 57 different countries; the most submissions were received from Turkey, followed by China and the United Kingdom. Retrospective data curation identified 80 studies that were initially registered as the incorrect study type, and were subsequently correct. The Kruskal-Wallis test identified a significant improvement in quality scores for registrations from February 2015 to October 2015 ( p  < 0.0001). Since its conception in February 2015, Research Registry ® has established itself as a new registry that is free, easy to

78 FR 14308 - International Cooperation on Harmonisation of Technical Requirements for Registration of...

Science.gov (United States)

2013-03-05

...] International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal... been developed for veterinary use by the International Cooperation on Harmonisation of Technical... regulatory authorities and industry associations to promote the international harmonization of regulatory...

Validation of non-rigid point-set registration methods using a porcine bladder pelvic phantom

Science.gov (United States)

Zakariaee, Roja; Hamarneh, Ghassan; Brown, Colin J.; Spadinger, Ingrid

2016-01-01

The problem of accurate dose accumulation in fractionated radiotherapy treatment for highly deformable organs, such as bladder, has garnered increasing interest over the past few years. However, more research is required in order to find a robust and efficient solution and to increase the accuracy over the current methods. The purpose of this study was to evaluate the feasibility and accuracy of utilizing non-rigid (affine or deformable) point-set registration in accumulating dose in bladder of different sizes and shapes. A pelvic phantom was built to house an ex vivo porcine bladder with fiducial landmarks adhered onto its surface. Four different volume fillings of the bladder were used (90, 180, 360 and 480 cc). The performance of MATLAB implementations of five different methods were compared, in aligning the bladder contour point-sets. The approaches evaluated were coherent point drift (CPD), gaussian mixture model, shape context, thin-plate spline robust point matching (TPS-RPM) and finite iterative closest point (ICP-finite). The evaluation metrics included registration runtime, target registration error (TRE), root-mean-square error (RMS) and Hausdorff distance (HD). The reference (source) dataset was alternated through all four points-sets, in order to study the effect of reference volume on the registration outcomes. While all deformable algorithms provided reasonable registration results, CPD provided the best TRE values (6.4 mm), and TPS-RPM yielded the best mean RMS and HD values (1.4 and 6.8 mm, respectively). ICP-finite was the fastest technique and TPS-RPM, the slowest.

Validation of non-rigid point-set registration methods using a porcine bladder pelvic phantom

International Nuclear Information System (INIS)

Zakariaee, Roja; Hamarneh, Ghassan; Brown, Colin J; Spadinger, Ingrid

2016-01-01

The problem of accurate dose accumulation in fractionated radiotherapy treatment for highly deformable organs, such as bladder, has garnered increasing interest over the past few years. However, more research is required in order to find a robust and efficient solution and to increase the accuracy over the current methods. The purpose of this study was to evaluate the feasibility and accuracy of utilizing non-rigid (affine or deformable) point-set registration in accumulating dose in bladder of different sizes and shapes. A pelvic phantom was built to house an ex vivo porcine bladder with fiducial landmarks adhered onto its surface. Four different volume fillings of the bladder were used (90, 180, 360 and 480 cc). The performance of MATLAB implementations of five different methods were compared, in aligning the bladder contour point-sets. The approaches evaluated were coherent point drift (CPD), gaussian mixture model, shape context, thin-plate spline robust point matching (TPS-RPM) and finite iterative closest point (ICP-finite). The evaluation metrics included registration runtime, target registration error (TRE), root-mean-square error (RMS) and Hausdorff distance (HD). The reference (source) dataset was alternated through all four points-sets, in order to study the effect of reference volume on the registration outcomes. While all deformable algorithms provided reasonable registration results, CPD provided the best TRE values (6.4 mm), and TPS-RPM yielded the best mean RMS and HD values (1.4 and 6.8 mm, respectively). ICP-finite was the fastest technique and TPS-RPM, the slowest. (paper)

Multi-Modality Registration And Fusion Of Medical Image Data

International Nuclear Information System (INIS)

Kassak, P.; Vencko, D.; Cerovsky, I.

2008-01-01

Digitalisation of health care providing facilities allows US to maximize the usage of digital data from one patient obtained by various modalities. Complex view on to the problem can be achieved from the site of morphology as well as functionality. Multi-modal registration and fusion of medical image data is one of the examples that provides improved insight and allows more precise approach and treatment. (author)

Template-based CTA to x-ray angio rigid registration of coronary arteries in frequency domain with automatic x-ray segmentation

Energy Technology Data Exchange (ETDEWEB)

Aksoy, Timur; Unal, Gozde [Sabanci University, Tuzla, Istanbul 34956 (Turkey); Demirci, Stefanie; Navab, Nassir [Computer Aided Medical Procedures (CAMP), Technical University of Munich, Garching, 85748 (Germany); Degertekin, Muzaffer [Yeditepe University Hospital, Istanbul 34752 (Turkey)

2013-10-15

Purpose: A key challenge for image guided coronary interventions is accurate and absolutely robust image registration bringing together preinterventional information extracted from a three-dimensional (3D) patient scan and live interventional image information. In this paper, the authors present a novel scheme for 3D to two-dimensional (2D) rigid registration of coronary arteries extracted from preoperative image scan (3D) and a single segmented intraoperative x-ray angio frame in frequency and spatial domains for real-time angiography interventions by C-arm fluoroscopy.Methods: Most existing rigid registration approaches require a close initialization due to the abundance of local minima and high complexity of search algorithms. The authors' method eliminates this requirement by transforming the projections into translation-invariant Fourier domain for estimating the 3D pose. For 3D rotation recovery, template Digitally Reconstructed Radiographs (DRR) as candidate poses of 3D vessels of segmented computed tomography angiography are produced by rotating the camera (image intensifier) around the DICOM angle values with a specific range as in C-arm setup. The authors have compared the 3D poses of template DRRs with the segmented x-ray after equalizing the scales in three domains, namely, Fourier magnitude, Fourier phase, and Fourier polar. The best rotation pose candidate was chosen by one of the highest similarity measures returned by the methods in these domains. It has been noted in literature that frequency domain methods are robust against noise and occlusion which was also validated by the authors' results. 3D translation of the volume was then recovered by distance-map based BFGS optimization well suited to convex structure of the authors' objective function without local minima due to distance maps. A novel automatic x-ray vessel segmentation was also performed in this study.Results: Final results were evaluated in 2D projection space for

Template-based CTA to x-ray angio rigid registration of coronary arteries in frequency domain with automatic x-ray segmentation

International Nuclear Information System (INIS)

Aksoy, Timur; Unal, Gozde; Demirci, Stefanie; Navab, Nassir; Degertekin, Muzaffer

2013-01-01

Purpose: A key challenge for image guided coronary interventions is accurate and absolutely robust image registration bringing together preinterventional information extracted from a three-dimensional (3D) patient scan and live interventional image information. In this paper, the authors present a novel scheme for 3D to two-dimensional (2D) rigid registration of coronary arteries extracted from preoperative image scan (3D) and a single segmented intraoperative x-ray angio frame in frequency and spatial domains for real-time angiography interventions by C-arm fluoroscopy.Methods: Most existing rigid registration approaches require a close initialization due to the abundance of local minima and high complexity of search algorithms. The authors' method eliminates this requirement by transforming the projections into translation-invariant Fourier domain for estimating the 3D pose. For 3D rotation recovery, template Digitally Reconstructed Radiographs (DRR) as candidate poses of 3D vessels of segmented computed tomography angiography are produced by rotating the camera (image intensifier) around the DICOM angle values with a specific range as in C-arm setup. The authors have compared the 3D poses of template DRRs with the segmented x-ray after equalizing the scales in three domains, namely, Fourier magnitude, Fourier phase, and Fourier polar. The best rotation pose candidate was chosen by one of the highest similarity measures returned by the methods in these domains. It has been noted in literature that frequency domain methods are robust against noise and occlusion which was also validated by the authors' results. 3D translation of the volume was then recovered by distance-map based BFGS optimization well suited to convex structure of the authors' objective function without local minima due to distance maps. A novel automatic x-ray vessel segmentation was also performed in this study.Results: Final results were evaluated in 2D projection space for patient data; and

A comparison of publicly available linear MRI stereotaxic registration techniques.

Science.gov (United States)

Dadar, Mahsa; Fonov, Vladimir S; Collins, D Louis

2018-07-01

atrophy related changes between passed and failed registrations. Our experiments show that the Revised BestLinReg had the best performance among the evaluated registration techniques while all techniques performed worse for images with higher levels of noise and non-uniformity as well as atrophy related changes. Copyright © 2018 Elsevier Inc. All rights reserved.

Locally orderless registration code

DEFF Research Database (Denmark)

2012-01-01

This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows.......This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows....

76 FR 57058 - International Cooperation on Harmonisation of Technical Requirements for Registration of...

Science.gov (United States)

2011-09-15

...] International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal... has been developed for veterinary use by the International Cooperation on Harmonisation of Technical... been undertaken by regulatory authorities and industry associations to promote the international...

Improving alignment in Tract-based spatial statistics: evaluation and optimization of image registration

NARCIS (Netherlands)

de Groot, Marius; Vernooij, Meike W.; Klein, Stefan; Ikram, M. Arfan; Vos, Frans M.; Smith, Stephen M.; Niessen, Wiro J.; Andersson, Jesper L. R.

2013-01-01

Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS

Improving alignment in Tract-based spatial statistics : Evaluation and optimization of image registration

NARCIS (Netherlands)

De Groot, M.; Vernooij, M.W.; Klein, S.; Arfan Ikram, M.; Vos, F.M.; Smith, S.M.; Niessen, W.J.; Andersson, J.L.R.

2013-01-01

Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS

Validation of an elastic registration technique to estimate anatomical lung modification in Non-Small-Cell Lung Cancer Tomotherapy

International Nuclear Information System (INIS)

Faggiano, Elena; Cattaneo, Giovanni M; Ciavarro, Cristina; Dell'Oca, Italo; Persano, Diego; Calandrino, Riccardo; Rizzo, Giovanna

2011-01-01

The study of lung parenchyma anatomical modification is useful to estimate dose discrepancies during the radiation treatment of Non-Small-Cell Lung Cancer (NSCLC) patients. We propose and validate a method, based on free-form deformation and mutual information, to elastically register planning kVCT with daily MVCT images, to estimate lung parenchyma modification during Tomotherapy. We analyzed 15 registrations between the planning kVCT and 3 MVCT images for each of the 5 NSCLC patients. Image registration accuracy was evaluated by visual inspection and, quantitatively, by Correlation Coefficients (CC) and Target Registration Errors (TRE). Finally, a lung volume correspondence analysis was performed to specifically evaluate registration accuracy in lungs. Results showed that elastic registration was always satisfactory, both qualitatively and quantitatively: TRE after elastic registration (average value of 3.6 mm) remained comparable and often smaller than voxel resolution. Lung volume variations were well estimated by elastic registration (average volume and centroid errors of 1.78% and 0.87 mm, respectively). Our results demonstrate that this method is able to estimate lung deformations in thorax MVCT, with an accuracy within 3.6 mm comparable or smaller than the voxel dimension of the kVCT and MVCT images. It could be used to estimate lung parenchyma dose variations in thoracic Tomotherapy

Medical Image Registration and Surgery Simulation

DEFF Research Database (Denmark)

Bro-Nielsen, Morten

1996-01-01

This thesis explores the application of physical models in medical image registration and surgery simulation. The continuum models of elasticity and viscous fluids are described in detail, and this knowledge is used as a basis for most of the methods described here. Real-time deformable models......, and the use of selective matrix vector multiplication. Fluid medical image registration A new and faster algorithm for non-rigid registration using viscous fluid models is presented. This algorithm replaces the core part of the original algorithm with multi-resolution convolution using a new filter, which...... growth is also presented. Using medical knowledge about the growth processes of the mandibular bone, a registration algorithm for time sequence images of the mandible is developed. Since this registration algorithm models the actual development of the mandible, it is possible to simulate the development...

Image registration assessment in radiotherapy image guidance based on control chart monitoring.

Science.gov (United States)

Xia, Wenyao; Breen, Stephen L

2018-04-01

Image guidance with cone beam computed tomography in radiotherapy can guarantee the precision and accuracy of patient positioning prior to treatment delivery. During the image guidance process, operators need to take great effort to evaluate the image guidance quality before correcting a patient's position. This work proposes an image registration assessment method based on control chart monitoring to reduce the effort taken by the operator. According to the control chart plotted by daily registration scores of each patient, the proposed method can quickly detect both alignment errors and image quality inconsistency. Therefore, the proposed method can provide a clear guideline for the operators to identify unacceptable image quality and unacceptable image registration with minimal effort. Experimental results demonstrate that by using control charts from a clinical database of 10 patients undergoing prostate radiotherapy, the proposed method can quickly identify out-of-control signals and find special cause of out-of-control registration events.

Fast time-of-flight camera based surface registration for radiotherapy patient positioning.

Science.gov (United States)

Placht, Simon; Stancanello, Joseph; Schaller, Christian; Balda, Michael; Angelopoulou, Elli

2012-01-01

This work introduces a rigid registration framework for patient positioning in radiotherapy, based on real-time surface acquisition by a time-of-flight (ToF) camera. Dynamic properties of the system are also investigated for future gating/tracking strategies. A novel preregistration algorithm, based on translation and rotation-invariant features representing surface structures, was developed. Using these features, corresponding three-dimensional points were computed in order to determine initial registration parameters. These parameters became a robust input to an accelerated version of the iterative closest point (ICP) algorithm for the fine-tuning of the registration result. Distance calibration and Kalman filtering were used to compensate for ToF-camera dependent noise. Additionally, the advantage of using the feature based preregistration over an "ICP only" strategy was evaluated, as well as the robustness of the rigid-transformation-based method to deformation. The proposed surface registration method was validated using phantom data. A mean target registration error (TRE) for translations and rotations of 1.62 ± 1.08 mm and 0.07° ± 0.05°, respectively, was achieved. There was a temporal delay of about 65 ms in the registration output, which can be seen as negligible considering the dynamics of biological systems. Feature based preregistration allowed for accurate and robust registrations even at very large initial displacements. Deformations affected the accuracy of the results, necessitating particular care in cases of deformed surfaces. The proposed solution is able to solve surface registration problems with an accuracy suitable for radiotherapy cases where external surfaces offer primary or complementary information to patient positioning. The system shows promising dynamic properties for its use in gating/tracking applications. The overall system is competitive with commonly-used surface registration technologies. Its main benefit is the

Fast time-of-flight camera based surface registration for radiotherapy patient positioning

International Nuclear Information System (INIS)

Placht, Simon; Stancanello, Joseph; Schaller, Christian; Balda, Michael; Angelopoulou, Elli

2012-01-01

Purpose: This work introduces a rigid registration framework for patient positioning in radiotherapy, based on real-time surface acquisition by a time-of-flight (ToF) camera. Dynamic properties of the system are also investigated for future gating/tracking strategies. Methods: A novel preregistration algorithm, based on translation and rotation-invariant features representing surface structures, was developed. Using these features, corresponding three-dimensional points were computed in order to determine initial registration parameters. These parameters became a robust input to an accelerated version of the iterative closest point (ICP) algorithm for the fine-tuning of the registration result. Distance calibration and Kalman filtering were used to compensate for ToF-camera dependent noise. Additionally, the advantage of using the feature based preregistration over an ''ICP only'' strategy was evaluated, as well as the robustness of the rigid-transformation-based method to deformation. Results: The proposed surface registration method was validated using phantom data. A mean target registration error (TRE) for translations and rotations of 1.62 ± 1.08 mm and 0.07 deg. ± 0.05 deg., respectively, was achieved. There was a temporal delay of about 65 ms in the registration output, which can be seen as negligible considering the dynamics of biological systems. Feature based preregistration allowed for accurate and robust registrations even at very large initial displacements. Deformations affected the accuracy of the results, necessitating particular care in cases of deformed surfaces. Conclusions: The proposed solution is able to solve surface registration problems with an accuracy suitable for radiotherapy cases where external surfaces offer primary or complementary information to patient positioning. The system shows promising dynamic properties for its use in gating/tracking applications. The overall system is competitive with commonly-used surface registration

Medical image registration for analysis

International Nuclear Information System (INIS)

Petrovic, V.

2006-01-01

Full text: Image registration techniques represent a rich family of image processing and analysis tools that aim to provide spatial correspondences across sets of medical images of similar and disparate anatomies and modalities. Image registration is a fundamental and usually the first step in medical image analysis and this paper presents a number of advanced techniques as well as demonstrates some of the advanced medical image analysis techniques they make possible. A number of both rigid and non-rigid medical image alignment algorithms of equivalent and merely consistent anatomical structures respectively are presented. The algorithms are compared in terms of their practical aims, inputs, computational complexity and level of operator (e.g. diagnostician) interaction. In particular, the focus of the methods discussion is placed on the applications and practical benefits of medical image registration. Results of medical image registration on a number of different imaging modalities and anatomies are presented demonstrating the accuracy and robustness of their application. Medical image registration is quickly becoming ubiquitous in medical imaging departments with the results of such algorithms increasingly used in complex medical image analysis and diagnostics. This paper aims to demonstrate at least part of the reason why

Non-rigid point set registration of curves: registration of the superficial vessel centerlines of the brain

Science.gov (United States)

Marreiros, Filipe M. M.; Wang, Chunliang; Rossitti, Sandro; Smedby, Örjan

2016-03-01

In this study we present a non-rigid point set registration for 3D curves (composed by 3D set of points). The method was evaluated in the task of registration of 3D superficial vessels of the brain where it was used to match vessel centerline points. It consists of a combination of the Coherent Point Drift (CPD) and the Thin-Plate Spline (TPS) semilandmarks. The CPD is used to perform the initial matching of centerline 3D points, while the semilandmark method iteratively relaxes/slides the points. For the evaluation, a Magnetic Resonance Angiography (MRA) dataset was used. Deformations were applied to the extracted vessels centerlines to simulate brain bulging and sinking, using a TPS deformation where a few control points were manipulated to obtain the desired transformation (T1). Once the correspondences are known, the corresponding points are used to define a new TPS deformation(T2). The errors are measured in the deformed space, by transforming the original points using T1 and T2 and measuring the distance between them. To simulate cases where the deformed vessel data is incomplete, parts of the reference vessels were cut and then deformed. Furthermore, anisotropic normally distributed noise was added. The results show that the error estimates (root mean square error and mean error) are below 1 mm, even in the presence of noise and incomplete data.

Promoting learning transfer in post registration education: a collaborative approach.

Science.gov (United States)

Finn, Frances L; Fensom, Sue A; Chesser-Smyth, Patricia

2010-01-01

Pre-registration nurse education in Ireland became a four year undergraduate honors degree programme in 2002 (Government of Ireland, 2000. The Nursing Education Forum Report. Dublin, Dublin Stationary Office.). Consequently, the Irish Government invested significant resources in post registration nursing education in order to align certificate and diploma trained nurses with the qualification levels of new graduates. However, a general concern amongst academic and clinical staff in the South East of Ireland was that there was limited impact of this initiative on practice. These concerns were addressed through a collaborative approach to the development and implementation of a new part-time post registration degree that incorporated an enquiry and practice based learning philosophy. The principles of learning transfer (Ford, K., 1994. Defining transfer of learning the meaning is in the answers. Adult Learning 5 (4), p. 2214.) underpinned the curriculum development and implementation process with the goal of reducing the theory practice gap. This paper reports on all four stages of the curriculum development process: exploration, design, implementation and evaluation (Quinn, F.M., 2002. Principles and Practices of Nurse Education, fourth ed. Nelson Thornes, Cheltenham), and the subsequent impact of learning transfer on practice development. Eclectic approaches of quantitative and qualitative data collection techniques were utilised in the evaluation. The evaluation of this project to date supports our view that this practice based enquiry curriculum promotes the transfer of learning in the application of knowledge to practice, impacting both student and service development.

Endorsement of the CONSORT statement by high-impact medical journals in China: a survey of instructions for authors and published papers.

Science.gov (United States)

Li, Xiao-qian; Tao, Kun-ming; Zhou, Qing-hui; Moher, David; Chen, Hong-yun; Wang, Fu-zhe; Ling, Chang-quan

2012-01-01

The CONSORT Statement is a reporting guideline for authors when reporting randomized controlled trials (RCTs). It offers a standard way for authors to prepare RCT reports. It has been endorsed by many high-impact medical journals and by international editorial groups. This study was conducted to assess the endorsement of the CONSORT Statement by high-impact medical journals in China by reviewing their instructions for authors. A total of 200 medical journals were selected according to the Chinese Science and Technology Journal Citation Reports, 195 of which publish clinical research papers. Their instructions for authors were reviewed and all texts mentioning the CONSORT Statement or CONSORT extension papers were extracted. Any mention of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URM) developed by the International Committee of Medical Journal Editors (ICMJE) or 'clinical trial registration' was also extracted. For journals endorsing the CONSORT Statement, their most recently published RCT reports were retrieved and evaluated to assess whether the journals have followed what the CONSORT Statement required. Out of the 195 medical journals publishing clinical research papers, only six (6/195, 3.08%) mentioned 'CONSORT' in their instructions for authors; out of the 200 medical journals surveyed, only 14 (14/200, 7.00%) mentioned 'ICMJE' or 'URM' in their instructions for authors, and another five journals stated in their instructions for authors that clinical trials should have trial registration numbers and that priority would be given to clinical trials which had been registered. Among the 62 RCT reports published in the six journals endorsing the CONSORT Statement, 20 (20/62, 32.26%) contained flow diagrams and only three (3/62, 4.84%) provided trial registration information. Medical journals in China endorsing either the CONSORT Statement or the ICMJE's URM constituted a small percentage of the total; all of these journals used

Image fusion between whole body FDG PET images and whole body MRI images using a full-automatic mutual information-based multimodality image registration software

International Nuclear Information System (INIS)

Uchida, Yoshitaka; Nakano, Yoshitada; Fujibuchi, Toshiou; Isobe, Tomoko; Kazama, Toshiki; Ito, Hisao

2006-01-01

We attempted image fusion between whole body PET and whole body MRI of thirty patients using a full-automatic mutual information (MI) -based multimodality image registration software and evaluated accuracy of this method and impact of the coregistrated imaging on diagnostic accuracy. For 25 of 30 fused images in body area, translating gaps were within 6 mm in all axes and rotating gaps were within 2 degrees around all axes. In head and neck area, considerably much gaps caused by difference of head inclination at imaging occurred in 16 patients, however these gaps were able to decrease by fused separately. In 6 patients, diagnostic accuracy using PET/MRI fused images was superior compared by PET image alone. This work shows that whole body FDG PET images and whole body MRI images can be automatically fused using MI-based multimodality image registration software accurately and this technique can add useful information when evaluating FDG PET images. (author)

40 CFR 68.160 - Registration.

Science.gov (United States)

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.160 Registration. (a) The owner or operator shall... substances handled in covered processes. (b) The registration shall include the following data: (1...

Mesh-to-raster region-of-interest-based nonrigid registration of multimodal images.

Science.gov (United States)

Tatano, Rosalia; Berkels, Benjamin; Deserno, Thomas M

2017-10-01

Region of interest (RoI) alignment in medical images plays a crucial role in diagnostics, procedure planning, treatment, and follow-up. Frequently, a model is represented as triangulated mesh while the patient data is provided from computed axial tomography scanners as pixel or voxel data. Previously, we presented a 2-D method for curve-to-pixel registration. This paper contributes (i) a general mesh-to-raster framework to register RoIs in multimodal images; (ii) a 3-D surface-to-voxel application, and (iii) a comprehensive quantitative evaluation in 2-D using ground truth (GT) provided by the simultaneous truth and performance level estimation (STAPLE) method. The registration is formulated as a minimization problem, where the objective consists of a data term, which involves the signed distance function of the RoI from the reference image and a higher order elastic regularizer for the deformation. The evaluation is based on quantitative light-induced fluoroscopy (QLF) and digital photography (DP) of decalcified teeth. STAPLE is computed on 150 image pairs from 32 subjects, each showing one corresponding tooth in both modalities. The RoI in each image is manually marked by three experts (900 curves in total). In the QLF-DP setting, our approach significantly outperforms the mutual information-based registration algorithm implemented with the Insight Segmentation and Registration Toolkit and Elastix.

A dental implant-based registration method for measuring mandibular kinematics using cone beam computed tomography-based fluoroscopy.

Science.gov (United States)

Lin, Cheng-Chung; Chen, Chien-Chih; Chen, Yunn-Jy; Lu, Tung-Wu; Hong, Shih-Wun

2014-01-01

This study aimed to develop and evaluate experimentally an implant-based registration method for measuring three-dimensional (3D) kinematics of the mandible and dental implants in the mandible based on dental cone beam computed tomography (CBCT), modified to include fluoroscopic function. The proposed implant-based registration method was based on the registration of CBCT data of implants/bones with single-plane fluoroscopy images. Seven registration conditions that included one to three implants were evaluated experimentally for their performance in a cadaveric porcine headmodel. The implant-based registration method was shown to have measurement errors (SD) of less than -0.2 (0.3) mm, 1.1 (2.2) mm, and 0.7 degrees (1.3 degrees) for the in-plane translation, out-of-plane translation, and all angular components, respectively, regardless of the number of implants used. The corresponding errors were reduced to less than -0.1 (0.1) mm, -0.3 (1.7) mm, and 0.5 degree (0.4 degree) when three implants were used. An implant-based registration method was developed to measure the 3D kinematics of the mandible/implants. With its high accuracy and reliability, the new method will be useful for measuring the 3D motion of the bones/implants for relevant applications.

Semi-automatic registration of 3D orthodontics models from photographs

Science.gov (United States)

Destrez, Raphaël.; Treuillet, Sylvie; Lucas, Yves; Albouy-Kissi, Benjamin

2013-03-01

In orthodontics, a common practice used to diagnose and plan the treatment is the dental cast. After digitization by a CT-scan or a laser scanner, the obtained 3D surface models can feed orthodontics numerical tools for computer-aided diagnosis and treatment planning. One of the pre-processing critical steps is the 3D registration of dental arches to obtain the occlusion of these numerical models. For this task, we propose a vision based method to automatically compute the registration based on photos of patient mouth. From a set of matched singular points between two photos and the dental 3D models, the rigid transformation to apply to the mandible to be in contact with the maxillary may be computed by minimizing the reprojection errors. During a precedent study, we established the feasibility of this visual registration approach with a manual selection of singular points. This paper addresses the issue of automatic point detection. Based on a priori knowledge, histogram thresholding and edge detection are used to extract specific points in 2D images. Concurrently, curvatures information detects 3D corresponding points. To improve the quality of the final registration, we also introduce a combined optimization of the projection matrix with the 2D/3D point positions. These new developments are evaluated on real data by considering the reprojection errors and the deviation angles after registration in respect to the manual reference occlusion realized by a specialist.

Operation of the radiation dose registration system for decontamination and related works

International Nuclear Information System (INIS)

Ogawa, Tsubasa; Yasutake, Tsuneo; Itoh, Atsuo; Miyabe, Kenjiro

2017-01-01

The radiation dose registration system for decontamination and related works was established on 15 November 2013. Radiation dose registration center and primary contractors of decontamination and related works manage decontamination registration and management system. As of 31 March 2017, 384 primary contractors joined in the radiation dose registration system for decontamination and related works. 383,087 quarterly exposure dose records for decontamination and related works were registered. Based on the registered data provided by the primary contractors, radiation dose registration center has released the statistical data that represent the radiation control status for workers engaged in radiation work at the work areas of decontamination and related works, etc. The statistical data shows that there were 40,377 workers engaged in decontamination and related works in 2015. The average exposure dose for workers was 0.6 mSv in 2015. The maximum exposure dose for workers was 7.8 mSv in 2015. Dose distribution by age of workers shows the range of 60 to 64 years old were most engaged in decontamination and related works in 2015. Dose distribution by gender of workers shows 97% of workers were male in 2015. From 2012 to 2015, about 95% of workers were exposed to radiation less than 3 mSv. And about 80% of workers were exposed to radiation less than 1 mSv. The average exposure dose per year was ranged from 0.5 to 0.7 mSv. (author)

Optical registration of spaceborne low light remote sensing camera

Science.gov (United States)

Li, Chong-yang; Hao, Yan-hui; Xu, Peng-mei; Wang, Dong-jie; Ma, Li-na; Zhao, Ying-long

2018-02-01

For the high precision requirement of spaceborne low light remote sensing camera optical registration, optical registration of dual channel for CCD and EMCCD is achieved by the high magnification optical registration system. System integration optical registration and accuracy of optical registration scheme for spaceborne low light remote sensing camera with short focal depth and wide field of view is proposed in this paper. It also includes analysis of parallel misalignment of CCD and accuracy of optical registration. Actual registration results show that imaging clearly, MTF and accuracy of optical registration meet requirements, it provide important guarantee to get high quality image data in orbit.

Skull registration for prone patient position using tracked ultrasound

Science.gov (United States)

Underwood, Grace; Ungi, Tamas; Baum, Zachary; Lasso, Andras; Kronreif, Gernot; Fichtinger, Gabor

2017-03-01

PURPOSE: Tracked navigation has become prevalent in neurosurgery. Problems with registration of a patient and a preoperative image arise when the patient is in a prone position. Surfaces accessible to optical tracking on the back of the head are unreliable for registration. We investigated the accuracy of surface-based registration using points accessible through tracked ultrasound. Using ultrasound allows access to bone surfaces that are not available through optical tracking. Tracked ultrasound could eliminate the need to work (i) under the table for registration and (ii) adjust the tracker between surgery and registration. In addition, tracked ultrasound could provide a non-invasive method in comparison to an alternative method of registration involving screw implantation. METHODS: A phantom study was performed to test the feasibility of tracked ultrasound for registration. An initial registration was performed to partially align the pre-operative computer tomography data and skull phantom. The initial registration was performed by an anatomical landmark registration. Surface points accessible by tracked ultrasound were collected and used to perform an Iterative Closest Point Algorithm. RESULTS: When the surface registration was compared to a ground truth landmark registration, the average TRE was found to be 1.6+/-0.1mm and the average distance of points off the skull surface was 0.6+/-0.1mm. CONCLUSION: The use of tracked ultrasound is feasible for registration of patients in prone position and eliminates the need to perform registration under the table. The translational component of error found was minimal. Therefore, the amount of TRE in registration is due to a rotational component of error.

AUTOMATIC REGISTRATION OF MULTI-SOURCE DATA USING MUTUAL INFORMATION

Directory of Open Access Journals (Sweden)

E. G. Parmehr

2012-07-01

Full Text Available Automatic image registration is a basic step in multi-sensor data integration in remote sensing and photogrammetric applications such as data fusion. The effectiveness of Mutual Information (MI as a technique for automated multi-sensor image registration has previously been demonstrated for medical and remote sensing applications. In this paper, a new General Weighted MI (GWMI approach that improves the robustness of MI to local maxima, particularly in the case of registering optical imagery and 3D point clouds, is presented. Two different methods including a Gaussian Mixture Model (GMM and Kernel Density Estimation have been used to define the weight function of joint probability, regardless of the modality of the data being registered. The Expectation Maximizing method is then used to estimate parameters of GMM, and in order to reduce the cost of computation, a multi-resolution strategy has been used. The performance of the proposed GWMI method for the registration of aerial orthotoimagery and LiDAR range and intensity information has been experimentally evaluated and the results obtained are presented.

Technical Note: DIRART- A software suite for deformable image registration and adaptive radiotherapy research

International Nuclear Information System (INIS)

Yang Deshan; Brame, Scott; El Naqa, Issam; Aditya, Apte; Wu Yu; Murty Goddu, S.; Mutic, Sasa; Deasy, Joseph O.; Low, Daniel A.

2011-01-01

Purpose: Recent years have witnessed tremendous progress in image guide radiotherapy technology and a growing interest in the possibilities for adapting treatment planning and delivery over the course of treatment. One obstacle faced by the research community has been the lack of a comprehensive open-source software toolkit dedicated for adaptive radiotherapy (ART). To address this need, the authors have developed a software suite called the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART). Methods: DIRART is an open-source toolkit developed in MATLAB. It is designed in an object-oriented style with focus on user-friendliness, features, and flexibility. It contains four classes of DIR algorithms, including the newer inverse consistency algorithms to provide consistent displacement vector field in both directions. It also contains common ART functions, an integrated graphical user interface, a variety of visualization and image-processing features, dose metric analysis functions, and interface routines. These interface routines make DIRART a powerful complement to the Computational Environment for Radiotherapy Research (CERR) and popular image-processing toolkits such as ITK. Results: DIRART provides a set of image processing/registration algorithms and postprocessing functions to facilitate the development and testing of DIR algorithms. It also offers a good amount of options for DIR results visualization, evaluation, and validation. Conclusions: By exchanging data with treatment planning systems via DICOM-RT files and CERR, and by bringing image registration algorithms closer to radiotherapy applications, DIRART is potentially a convenient and flexible platform that may facilitate ART and DIR research.

Solid Mesh Registration for Radiotherapy Treatment Planning

DEFF Research Database (Denmark)

Noe, Karsten Østergaard; Sørensen, Thomas Sangild

2010-01-01

We present an algorithm for solid organ registration of pre-segmented data represented as tetrahedral meshes. Registration of the organ surface is driven by force terms based on a distance field representation of the source and reference shapes. Registration of internal morphology is achieved usi...

[Ideas about registration for sodium hyaluronate facial derma fillers].

Science.gov (United States)

Zhao, Peng; Shi, Xinli; Liu, Wenbo; Lu, Hong

2012-09-01

To review the registration and technical data for sodium hyaluronate facial derma fillers. Recent literature concerning registration for sodium hyaluronate facial derma fillers was reviewed and analyzed. The aspects on registration for sodium hyaluronate facial derma fillers include nominating the product, dividing registration unit, filling in a registration application form, preparing the technical data, developing the standard, and developing a registration specification. The main difficulty in registration is how to prepare the research data of that product, so the manufacturers need to enhance their basic research ability and work out a scientific technique routing which could ensure the safety and effectiveness of the product, also help to set up the supportive documents to medical device registration.

Pro Forma Registration of Companies

DEFF Research Database (Denmark)

Werlauff, Erik

2010-01-01

The article analyses the view taken by Community law on companies' pro forma registration in another EU or EEA country. Community law recognises pro forma registration under company law, i.e. a brass plate is sufficient, whereas it does not recognise pro forma registration under tax law, i.......e. a brass plate is not sufficient. The article provides reasons for the differential treatment of the two contexts and clarifies the difference on the basis of the Hubbard criterion, in which it was ruled that the effectiveness of Community law cannot vary according to the various branches of national law....

Fiducial-based registration with a touchable region model.

Science.gov (United States)

Kim, Sungmin; Kazanzides, Peter

2017-02-01

Image-guided surgery requires registration between an image coordinate system and an intraoperative coordinate system that is typically referenced to a tracking device. In fiducial-based registration methods, this is achieved by localizing points (fiducials) in each coordinate system. Often, both localizations are performed manually, first by picking a fiducial point in the image and then by using a hand-held tracked pointer to physically touch the corresponding fiducial on the patient. These manual procedures introduce localization error that is user-dependent and can significantly decrease registration accuracy. Thus, there is a need for a registration method that is tolerant of imprecise fiducial localization in the preoperative and intraoperative phases. We propose the iterative closest touchable point (ICTP) registration framework, which uses model-based localization and a touchable region model. This method consists of three stages: (1) fiducial marker localization in image space, using a fiducial marker model, (2) initial registration with paired-point registration, and (3) fine registration based on the iterative closest point method. We perform phantom experiments with a fiducial marker design that is commonly used in neurosurgery. The results demonstrate that ICTP can provide accuracy improvements compared to the standard paired-point registration method that is widely used for surgical navigation and surgical robot systems, especially in cases where the surgeon introduces large localization errors. The results demonstrate that the proposed method can reduce the effect of the surgeon's localization performance on the accuracy of registration, thereby producing more consistent and less user-dependent registration outcomes.

40 CFR 152.115 - Conditions of registration.

Science.gov (United States)

2010-07-01

... specify any provisions for sale and distribution of existing stocks of the pesticide product. (3) The... PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Agency Review of Applications § 152.115 Conditions of registration. (a) Substantially similar products and new uses. Each registration issued under § 152.113 shall...

Validation of an algorithm for the nonrigid registration of longitudinal breast MR images using realistic phantoms

Science.gov (United States)

Li, Xia; Dawant, Benoit M.; Welch, E. Brian; Chakravarthy, A. Bapsi; Xu, Lei; Mayer, Ingrid; Kelley, Mark; Meszoely, Ingrid; Means-Powell, Julie; Gore, John C.; Yankeelov, Thomas E.

2010-01-01

Purpose: The authors present a method to validate coregistration of breast magnetic resonance images obtained at multiple time points during the course of treatment. In performing sequential registration of breast images, the effects of patient repositioning, as well as possible changes in tumor shape and volume, must be considered. The authors accomplish this by extending the adaptive bases algorithm (ABA) to include a tumor-volume preserving constraint in the cost function. In this study, the authors evaluate this approach using a novel validation method that simulates not only the bulk deformation associated with breast MR images obtained at different time points, but also the reduction in tumor volume typically observed as a response to neoadjuvant chemotherapy. Methods: For each of the six patients, high-resolution 3D contrast enhanced T1-weighted images were obtained before treatment, after one cycle of chemotherapy and at the conclusion of chemotherapy. To evaluate the effects of decreasing tumor size during the course of therapy, simulations were run in which the tumor in the original images was contracted by 25%, 50%, 75%, and 95%, respectively. The contracted area was then filled using texture from local healthy appearing tissue. Next, to simulate the post-treatment data, the simulated (i.e., contracted tumor) images were coregistered to the experimentally measured post-treatment images using a surface registration. By comparing the deformations generated by the constrained and unconstrained version of ABA, the authors assessed the accuracy of the registration algorithms. The authors also applied the two algorithms on experimental data to study the tumor volume changes, the value of the constraint, and the smoothness of transformations. Results: For the six patient data sets, the average voxel shift error (mean±standard deviation) for the ABA with constraint was 0.45±0.37, 0.97±0.83, 1.43±0.96, and 1.80±1.17 mm for the 25%, 50%, 75%, and 95

Nonrigid registration with tissue-dependent filtering of the deformation field

International Nuclear Information System (INIS)

Staring, Marius; Klein, Stefan; Pluim, Josien P W

2007-01-01

In present-day medical practice it is often necessary to nonrigidly align image data. Current registration algorithms do not generally take the characteristics of tissue into account. Consequently, rigid tissue, such as bone, can be deformed elastically, growth of tumours may be concealed, and contrast-enhanced structures may be reduced in volume. We propose a method to locally adapt the deformation field at structures that must be kept rigid, using a tissue-dependent filtering technique. This adaptive filtering of the deformation field results in locally linear transformations without scaling or shearing. The degree of filtering is related to tissue stiffness: more filtering is applied at stiff tissue locations, less at parts of the image containing nonrigid tissue. The tissue-dependent filter is incorporated in a commonly used registration algorithm, using mutual information as a similarity measure and cubic B-splines to model the deformation field. The new registration algorithm is compared with this popular method. Evaluation of the proposed tissue-dependent filtering is performed on 3D computed tomography (CT) data of the thorax and on 2D digital subtraction angiography (DSA) images. The results show that tissue-dependent filtering of the deformation field leads to improved registration results: tumour volumes and vessel widths are preserved rather than affected

18F-FDG PET and high-resolution MRI co-registration for pre-surgical evaluation of patients with conventional MRI-negative refractory extra-temporal lobe epilepsy.

Science.gov (United States)

Ding, Yao; Zhu, Yuankai; Jiang, Biao; Zhou, Yongji; Jin, Bo; Hou, Haifeng; Wu, Shuang; Zhu, Junming; Wang, Zhong Irene; Wong, Chong H; Ding, Meiping; Zhang, Hong; Wang, Shuang; Tian, Mei

2018-04-18

Epilepsy that originates outside of the temporal lobe can present some of the most challenging problems for surgical therapy, especially for patients with conventional magnetic resonance imaging (MRI)-negative refractory extra-temporal lobe epilepsy (ETLE). This study aimed to evaluate the clinical value of pre-surgical 18 F-fluoro-deoxy-glucose positron emission tomography ( 18 F-FDG PET) and high-resolution MRI (HR-MRI) co-registration in patients with conventional MRI-negative refractory ETLE, and compare their surgical outcomes. Sixty-seven patients with conventional MRI-negative refractory ETLE were prospectively included for pre-surgical 18 F-FDG PET and HR-MRI examinations. Under the guidance of 18 F-FDG PET and HR-MRI co-registration, HR-MRI images were re-read. Based on the image result changes from first reading to re-reading, patients were divided into three groups: Change-1 (lesions of subtle abnormality could be identified in re-read), Change-2 (non-specific abnormalities reported in the first reading were considered as lesions on HR-MRI re-read) and No-change. Post-surgical follow-ups were conducted for up to 59 months. Visual analysis of 18 F-FDG PET showed focal or regional abnormality in 46 patients (68.6%), while the abnormal rate increased to 94.0% (P evaluation by co-registration of 18 F-FDG PET and HR-MRI could improve the identification of the epileptogenic onset zone (EOZ), and may further guide the surgical decision-making and improve the outcome of the refractory ETLE with normal conventional MRI; therefore, it should be recommended as a standard procedure for pre-surgical evaluation of these patients.

Project Management Series Case Study: The Office of Registration and Records

Science.gov (United States)

Burgher, Karl E.; Snyder, Michael

2012-01-01

This is the third in a series of eight articles on project management (PM) in the academy. In this article, the authors describe the step-by-step implementation of a structural change to Indiana State University's (ISU's) Office of Registration and Records (ORR). The process described may vary as it is implemented elsewhere, but the authors…

Whole-body gene expression pattern registration in Platynereis larvae.

Science.gov (United States)

Asadulina, Albina; Panzera, Aurora; Verasztó, Csaba; Liebig, Christian; Jékely, Gáspár

2012-12-03

Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the comparison of gene expression patterns is a widely used approach, such standardized anatomical atlases would allow a more rigorous assessment of the conservation of and changes in gene expression patterns during micro- and macroevolutionary time scales. Due to its small size and invariant early development, the annelid Platynereis dumerilii is particularly well suited for such studies. Recently a reference template with registered gene expression patterns has been generated for the anterior part (episphere) of the Platynereis trochophore larva and used for the detailed study of neuronal development. Here we introduce and evaluate a method for whole-body gene expression pattern registration for Platynereis trochophore and nectochaete larvae based on whole-mount in situ hybridization, confocal microscopy, and image registration. We achieved high-resolution whole-body scanning using the mounting medium 2,2'-thiodiethanol (TDE), which allows the matching of the refractive index of the sample to that of glass and immersion oil thereby reducing spherical aberration and improving depth penetration. This approach allowed us to scan entire whole-mount larvae stained with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP) in situ hybridization and counterstained fluorescently with an acetylated-tubulin antibody and the nuclear stain 4'6-diamidino-2-phenylindole (DAPI). Due to the submicron isotropic voxel size whole-mount larvae could be scanned in any orientation. Based on the whole-body scans, we generated four different reference templates by the iterative registration and averaging of 40 individual image stacks using either the acetylated-tubulin or the nuclear-stain signal for each developmental stage. We then registered to these templates the

Whole-body gene expression pattern registration in Platynereis larvae

Directory of Open Access Journals (Sweden)

Asadulina Albina

2012-12-01

Full Text Available Abstract Background Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the comparison of gene expression patterns is a widely used approach, such standardized anatomical atlases would allow a more rigorous assessment of the conservation of and changes in gene expression patterns during micro- and macroevolutionary time scales. Due to its small size and invariant early development, the annelid Platynereis dumerilii is particularly well suited for such studies. Recently a reference template with registered gene expression patterns has been generated for the anterior part (episphere of the Platynereis trochophore larva and used for the detailed study of neuronal development. Results Here we introduce and evaluate a method for whole-body gene expression pattern registration for Platynereis trochophore and nectochaete larvae based on whole-mount in situ hybridization, confocal microscopy, and image registration. We achieved high-resolution whole-body scanning using the mounting medium 2,2’-thiodiethanol (TDE, which allows the matching of the refractive index of the sample to that of glass and immersion oil thereby reducing spherical aberration and improving depth penetration. This approach allowed us to scan entire whole-mount larvae stained with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP in situ hybridization and counterstained fluorescently with an acetylated-tubulin antibody and the nuclear stain 4’6-diamidino-2-phenylindole (DAPI. Due to the submicron isotropic voxel size whole-mount larvae could be scanned in any orientation. Based on the whole-body scans, we generated four different reference templates by the iterative registration and averaging of 40 individual image stacks using either the acetylated-tubulin or the nuclear-stain signal for each developmental

The comprehensive registration and information system of radiation protection regulatory authority in the Czech Republic

International Nuclear Information System (INIS)

Petrova, K.

2004-01-01

The central registration system in radiation protection is created in the Czech Republic since the 1997 year. Since that time the central registries of licensees, ionizing radiation sources (IRS) and occupational of workers doses has been developed by the State Office for Nuclear Safety (SUJB) in accordance with the demands of the new Czech legislation. The core of this complex information system is created by the Central Register of Licensees (CRL). The Central Register of Occupational Exposure (CROE) and the Central Register of Ionising Radiation Sources (CRIRS) are connected to CRL and provides with the list of workers their doses and relevant sources for each licensee. The Central Register of Approvals (CRA) issued by SUJB has been also created in 2002 and it was implemented into the system. The further register of inspections is recently under development. The whole system is operated in Oracle database. CRL registers all relevant information on the level of licensee, their workplaces and also on the level of smaller working units (labs, buildings, ..) where is necessary for more precise information about the placement of sources. The data are updated continuously. CROE collects personal and dosimetric data for all monitored workers in whole country. This register also includes the information on the personal radiation passports distributed by SUJB to external workers. CRIRS registers sealed IRS, devices with sealed IRS, generators and specification of workplaces with unsealed IRS. Users are obliged to report information on new source specified by Decree on radiation protection within one months. They shall report also all changes of registered data including the transfer of source to another user or to final disposal. CRA enables to issue automatically the licence in unified form and provides users with the different control tools of issued licences. Described comprehensive information system serves as very important and useful tool for effective regulation

SU-F-J-96: Comparison of Frame-Based and Mutual Information Registration Techniques for CT and MR Image Sets

Energy Technology Data Exchange (ETDEWEB)

Popple, R; Bredel, M; Brezovich, I; Dobelbower, M; Fisher, W; Fiveash, J; Guthrie, B; Riley, K; Wu, X [The University of Alabama at Birmingham, Birmingham, AL (United States)

2016-06-15

Purpose: To compare the accuracy of CT-MR registration using a mutual information method with registration using a frame-based localizer box. Methods: Ten patients having the Leksell head frame and scanned with a modality specific localizer box were imported into the treatment planning system. The fiducial rods of the localizer box were contoured on both the MR and CT scans. The skull was contoured on the CT images. The MR and CT images were registered by two methods. The frame-based method used the transformation that minimized the mean square distance of the centroids of the contours of the fiducial rods from a mathematical model of the localizer. The mutual information method used automated image registration tools in the TPS and was restricted to a volume-of-interest defined by the skull contours with a 5 mm margin. For each case, the two registrations were adjusted by two evaluation teams, each comprised of an experienced radiation oncologist and neurosurgeon, to optimize alignment in the region of the brainstem. The teams were blinded to the registration method. Results: The mean adjustment was 0.4 mm (range 0 to 2 mm) and 0.2 mm (range 0 to 1 mm) for the frame and mutual information methods, respectively. The median difference between the frame and mutual information registrations was 0.3 mm, but was not statistically significant using the Wilcoxon signed rank test (p=0.37). Conclusion: The difference between frame and mutual information registration techniques was neither statistically significant nor, for most applications, clinically important. These results suggest that mutual information is equivalent to frame-based image registration for radiosurgery. Work is ongoing to add additional evaluators and to assess the differences between evaluators.

32 CFR 635.27 - Vehicle Registration System.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Vehicle Registration System. 635.27 Section 635.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS LAW ENFORCEMENT REPORTING Offense Reporting § 635.27 Vehicle Registration System. The Vehicle Registration System (VR...

37 CFR 1.293 - Statutory invention registration.

Science.gov (United States)

2010-07-01

... the date of publication of the statutory invention registration; (2) The required fee for filing a request for publication of a statutory invention registration as provided for in § 1.17 (n) or (o); (3) A... application. (b) Any request for publication of a statutory invention registration must include the following...

Landmark Optimization Using Local Curvature for Point-Based Nonlinear Rodent Brain Image Registration

Directory of Open Access Journals (Sweden)

Yutong Liu

2012-01-01

Full Text Available Purpose. To develop a technique to automate landmark selection for point-based interpolating transformations for nonlinear medical image registration. Materials and Methods. Interpolating transformations were calculated from homologous point landmarks on the source (image to be transformed and target (reference image. Point landmarks are placed at regular intervals on contours of anatomical features, and their positions are optimized along the contour surface by a function composed of curvature similarity and displacements of the homologous landmarks. The method was evaluated in two cases (=5 each. In one, MRI was registered to histological sections; in the second, geometric distortions in EPI MRI were corrected. Normalized mutual information and target registration error were calculated to compare the registration accuracy of the automatically and manually generated landmarks. Results. Statistical analyses demonstrated significant improvement (<0.05 in registration accuracy by landmark optimization in most data sets and trends towards improvement (<0.1 in others as compared to manual landmark selection.

Registration of FA and T1-weighted MRI data of healthy human brain based on template matching and normalized cross-correlation.

Science.gov (United States)

Malinsky, Milos; Peter, Roman; Hodneland, Erlend; Lundervold, Astri J; Lundervold, Arvid; Jan, Jiri

2013-08-01

In this work, we propose a new approach for three-dimensional registration of MR fractional anisotropy images with T1-weighted anatomy images of human brain. From the clinical point of view, this accurate coregistration allows precise detection of nerve fibers that is essential in neuroscience. A template matching algorithm combined with normalized cross-correlation was used for this registration task. To show the suitability of the proposed method, it was compared with the normalized mutual information-based B-spline registration provided by the Elastix software library, considered a reference method. We also propose a general framework for the evaluation of robustness and reliability of both registration methods. Both registration methods were tested by four evaluation criteria on a dataset consisting of 74 healthy subjects. The template matching algorithm has shown more reliable results than the reference method in registration of the MR fractional anisotropy and T1 anatomy image data. Significant differences were observed in the regions splenium of corpus callosum and genu of corpus callosum, considered very important areas of brain connectivity. We demonstrate that, in this registration task, the currently used mutual information-based parametric registration can be replaced by more accurate local template matching utilizing the normalized cross-correlation similarity measure.

46 CFR 401.220 - Registration of pilots.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Registration of pilots. 401.220 Section 401.220 Shipping... Registration of Pilots § 401.220 Registration of pilots. (a) The Director shall determine the number of pilots... waters of the Great Lakes and to provide for equitable participation of United States Registered Pilots...

Quantitative evaluation of an image registration method for a NIPAM gel dosimeter

International Nuclear Information System (INIS)

Chang, Yuan-Jen; Yao, Chun-Hsu; Wu, Jay; Hsieh, Bor-Tsung; Tsang, Yuk-Wah; Chen, Chin-Hsing

2015-01-01

One of the problems in obtaining quality results is image registration when a gel dosimeter is used in conjunction with optical computed tomography (CT). This study proposes a passive alignment mechanism to obtain a precisely measured dose map. A holder plate with two pin–hole pairs is placed on the gel container cap. These two pin–hole pairs attach the gel container to the vertical shaft and can be precisely aligned with the rotation center of the vertical shaft at any time. Accordingly, a better reconstructed image quality is obtained. After obtaining a precisely measured dose map, the scale invariant feature transform (SIFT)-flow algorithm is utilized as an image registration method to align the treatment plan software (TPS) image with the measured dose map image. The results show that the gamma pass rate for the single-field irradiation increases from 83.39% to 94.03% when the algorithm is applied. And the gamma pass rate for the five-field irradiation treatment plan increases from 87.36% to 94.34%. The translation, scaling, and rotation occurring in the dose map image constructed using an optical CT scanner are also aligned with those in the TPS image using the SIFT-flow algorithm. Accordingly, improved gamma comparison results and a higher gamma pass rate are obtained. - Highlights: • A passive alignment method for obtaining a precisely measured dose map is developed. • The SIFT-flow algorithm is adopted as an image registration method for the gel dosimeter. • The SIFT-flow algorithm increases the gamma pass rate from 83.39% to 94.03% for the single-field irradiation. • The SIFT-flow algorithm increases the gamma pass rate from 87.36% to 94.34% for the five-field irradiation. • The translation, scaling, and rotation in the measured dose map image are aligned with those in the TPS image using the SIFT-flow algorithm

Quantitative evaluation of an image registration method for a NIPAM gel dosimeter

Energy Technology Data Exchange (ETDEWEB)

Chang, Yuan-Jen [Department of Management Information Systems, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China); Yao, Chun-Hsu [School of Chinese Medicine, China Medical University, Taichung, Taiwan (R.O.C.) (China); Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan (R.O.C.) (China); Department of Biomedical Informatics, Asia University, Taichung, Taiwan (R.O.C.) (China); Wu, Jay [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (R.O.C.) (China); Hsieh, Bor-Tsung [Department of Biomedical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan (R.O.C.) (China); Tsang, Yuk-Wah [Department of Radiation Oncology, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi, Taiwan (R.O.C.) (China); Chen, Chin-Hsing [Department of Management Information Systems, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City, Taiwan (R.O.C.) (China)

2015-06-01

One of the problems in obtaining quality results is image registration when a gel dosimeter is used in conjunction with optical computed tomography (CT). This study proposes a passive alignment mechanism to obtain a precisely measured dose map. A holder plate with two pin–hole pairs is placed on the gel container cap. These two pin–hole pairs attach the gel container to the vertical shaft and can be precisely aligned with the rotation center of the vertical shaft at any time. Accordingly, a better reconstructed image quality is obtained. After obtaining a precisely measured dose map, the scale invariant feature transform (SIFT)-flow algorithm is utilized as an image registration method to align the treatment plan software (TPS) image with the measured dose map image. The results show that the gamma pass rate for the single-field irradiation increases from 83.39% to 94.03% when the algorithm is applied. And the gamma pass rate for the five-field irradiation treatment plan increases from 87.36% to 94.34%. The translation, scaling, and rotation occurring in the dose map image constructed using an optical CT scanner are also aligned with those in the TPS image using the SIFT-flow algorithm. Accordingly, improved gamma comparison results and a higher gamma pass rate are obtained. - Highlights: • A passive alignment method for obtaining a precisely measured dose map is developed. • The SIFT-flow algorithm is adopted as an image registration method for the gel dosimeter. • The SIFT-flow algorithm increases the gamma pass rate from 83.39% to 94.03% for the single-field irradiation. • The SIFT-flow algorithm increases the gamma pass rate from 87.36% to 94.34% for the five-field irradiation. • The translation, scaling, and rotation in the measured dose map image are aligned with those in the TPS image using the SIFT-flow algorithm.

Nonrigid Registration of Prostate Diffusion-Weighted MRI

Directory of Open Access Journals (Sweden)

Lei Hao

2017-01-01

Full Text Available Motion and deformation are common in prostate diffusion-weighted magnetic resonance imaging (DWI during acquisition. These misalignments lead to errors in estimating an apparent diffusion coefficient (ADC map fitted with DWI. To address this problem, we propose an image registration algorithm to align the prostate DWI and improve ADC map. First, we apply affine transformation to DWI to correct intraslice motions. Then, nonrigid registration based on free-form deformation (FFD is used to compensate for intraimage deformations. To evaluate the influence of the proposed algorithm on ADC values, we perform statistical experiments in three schemes: no processing of the DWI, with the affine transform approach, and with FFD. The experimental results show that our proposed algorithm can correct the misalignment of prostate DWI and decrease the artifacts of ROI in the ADC maps. These ADC maps thus obtain sharper contours of lesions, which are helpful for improving the diagnosis and clinical staging of prostate cancer.

Quality assurance of CT-PET alignment and image registration for radiation treatment planning

International Nuclear Information System (INIS)

Gong, S.J.; O'Keefe, G.J.; Gunawardana, D.H.

2005-01-01

A multi-layer point source phantom was first used to calibrate and verify the CT-PET system alignment. A partial whole-body Aldcrson RANDO Man Phantom (head through mid-femur) was externally and internally marked with small metal cannulas filled with 18F-FDG and then scanned with both modalities. Six series of phantom studies with different acquisition settings and scan positions were performed to reveal possible system bias and evaluate the accuracy and reliabilities of Philips Syntegra program in image alignment, coregistration and fusion. The registration error was assessed quantitatively by measuring the root-mean-square distance between the iso-centers of corresponding fiducial marker geometries in reference CT volumes and transformed CT or PET volumes. Results: Experimental data confirms the accuracy of manual, parameter, point and image-based registration using Syntegra is better than 2 mm. Comparisons between blind and cross definition of iso-centers of fiducial marks indicate that the fused CT and PET is superior to visual correlation of CT and PET side-by-side. Conclusion: In this work we demonstrate the QA procedures of Gemini image alignment and registration. Syntegra produces intrinsic and robust multi-modality image registration and fusion with careful user interaction. The registration accuracy is generally better than the spatial resolution of the PET scanner used and this appears to be sufficient for most RTP CT-PET registration procedures

TU-A-19A-01: Image Registration I: Deformable Image Registration, Contour Propagation and Dose Mapping: 101 and 201

Energy Technology Data Exchange (ETDEWEB)

Kessler, M [The University of Michigan, Ann Arbor, MI (United States)

2014-06-15

Deformable image registration, contour propagation and dose mapping have become common, possibly essential tools for modern image-guided radiation therapy. Historically, these tools have been largely developed at academic medical centers and used in a rather limited and well controlled fashion. Today these tools are now available to the radiotherapy community at large, both as stand-alone applications and as integrated components of both treatment planning and treatment delivery systems. Unfortunately, the details of how these tools work and their limitations are not generally documented or described by the vendors that provide them. Although “it looks right”, determining that unphysical deformations may have occurred is crucial. Because of this, understanding how and when to use, and not use these tools to support everyday clinical decisions is far from straight forward. The goal of this session will be to present both the theory (basic and advanced) and practical clinical use of deformable image registration, contour propagation and dose mapping. To the extent possible, the “secret sauce” that different vendor use to produce reasonable/acceptable results will be described. A detailed explanation of the possible sources of errors and actual examples of these will be presented. Knowing the underlying principles of the process and understanding the confounding factors will help the practicing medical physicist be better able to make decisions (about making decisions) using these tools available. Learning Objectives: Understand the basic (101) and advanced (201) principles of deformable image registration, contour propagation and dose mapping data mapping. Understand the sources and impact of errors in registration and data mapping and the methods for evaluating the performance of these tools. Understand the clinical use and value of these tools, especially when used as a “black box”.

Deformable 4DCT lung registration with vessel bifurcations

International Nuclear Information System (INIS)

Hilsmann, A.; Vik, T.; Kaus, M.; Franks, K.; Bissonette, J.P.; Purdie, T.; Beziak, A.; Aach, T.

2007-01-01

In radiotherapy planning of lung cancer, breathing motion causes uncertainty in the determination of the target volume. Image registration makes it possible to get information about the deformation of the lung and the tumor movement in the respiratory cycle from a few images. A dedicated, automatic, landmark-based technique was developed that finds corresponding vessel bifurcations. Hereby, we developed criteria to characterize pronounced bifurcations for which correspondence finding was more stable and accurate. The bifurcations were extracted from automatically segmented vessel trees in maximum inhale and maximum exhale CT thorax data sets. To find corresponding bifurcations in both data sets we used the shape context approach of Belongie et al. Finally, a volumetric lung deformation was obtained using thin-plate spline interpolation and affine registration. The method is evaluated on 10 4D-CT data sets of patients with lung cancer. (orig.)

Guideline development and impact assessment for registration of medical, dental and veterinary x-ray apparatus

International Nuclear Information System (INIS)

Colgan, P.; Harrison, D.; Moore, W.

1996-01-01

Under the NSW Radiation Control Act 1990, radiation apparatus used for diagnostic medical, dental and veterinary purposes will be required to become registered. The inspection required prior to registration will be conducted by a Consulting Radiation Expert who has been accredited by the Environment Protection Authority (EPA) as being competent in the field of quality assurance assessment of radiation apparatus used for diagnostic medical, dental and veterinary purposes. When regulating any activity in NSW, there is a requirement to undertake a regulatory impact statement of the proposed regulation. In addition, the introduction of any accompanying guideline requires a cost-benefit analysis. Costs may include enforcement, administrative and compliance activities. The calculation of benefit relies heavily on the improvement in apparatus performance (and hence dose reduction) that can be obtained with the introduction of a mandatory practice such as apparatus registration. This paper discusses the development of the registration guideline for NSW, including a summary of the public comments received. It further discusses the methodology and data used for the accompanying cost-benefit analysis. Information in this paper is presented in three parts: EPA field survey, cost analysis, and benefit analysis. For NSW it was estimated that the introduction of registration of these apparatus, over a two year period, would result in early replacement and repair costs (present values) to the medical industry of between $5.7 and $11.0 million, with an additional $2.5 million in EPA enforcement costs. The introduction of the proposed system of registration is expected to result in an estimated savings in quantifiable health detriment costs to NSW of between $11.8 and $17.7 million, and reduce the risk of radiation induced mortality. (authors)

SU-E-J-266: A Pitfall of a Deformable Image Registration in Lung Cancer

Energy Technology Data Exchange (ETDEWEB)

Sugawara, Y [The National Center for Global Health and Medicine, Shinjuku, Tokyo (Japan); Tachibana, H [The National Cancer Center Hospital East, Kashiwa, Chiba (Japan); Moriya, S [Komazawa University, Setagaya, Tokyo (Japan); Sawant, A [UT Southwestern Medical Center, Dallas, TX (United States)

2014-06-01

Purpose: For four-dimensional (4D) planning and adaptive radiotherapy, deformable image registration (DIR) is needed and the accuracy is essential. We evaluated the accuracy of one free-downloadable DIR software library package (NiftyReg) and one commercial DIR software (MIM) in lung SBRT cancer patients. Methods: A rigid and non-rigid registrations were implemented to our in-house software. The non-rigid registration algorithm of the NiftyReg and MIM was based on the free-form deformation. The accuracy of the two software was evaluated when contoured structures to peak-inhale and peak-exhale 4DCT image data sets were measured using the dice similarity coefficient (DSC). The evaluation was performed in 20 lung SBRT patients. Results: In our visual evaluation, the eighteen cases show good agreement between the deformed structures for the peak-inhale phase and the peak-exhale phase structures (more than 0.8 DSC value). In the evaluation of the DSC in-house software, averaged DSC values of GTV and lung, heart, spinal cord, stomach and body were 0.862 and 0.979, 0.932, 0.974, 0.860, 0.998, respectively. As the Resultof the registration using the MIM program in the two cases which had less than 0.7 DSC value when analyzed using the in-house software, the DSC value were improved to 0.8. The CT images in a case with low DSC value shows the tumor was surrounded by the structure with the similar CT values, which were the chest wall or the diaphragm. Conclusion: Not only a free-downloadable DIR software but also a commercial software may provide unexpected results and there is a possibility that the results would make us misjudge the treatment planning. Therefore, we recommend that a commissioning test of any DIR software should be performed before clinical use and we should understand the characteristics of the software.

SU-E-J-266: A Pitfall of a Deformable Image Registration in Lung Cancer

International Nuclear Information System (INIS)

Sugawara, Y; Tachibana, H; Moriya, S; Sawant, A

2014-01-01

Purpose: For four-dimensional (4D) planning and adaptive radiotherapy, deformable image registration (DIR) is needed and the accuracy is essential. We evaluated the accuracy of one free-downloadable DIR software library package (NiftyReg) and one commercial DIR software (MIM) in lung SBRT cancer patients. Methods: A rigid and non-rigid registrations were implemented to our in-house software. The non-rigid registration algorithm of the NiftyReg and MIM was based on the free-form deformation. The accuracy of the two software was evaluated when contoured structures to peak-inhale and peak-exhale 4DCT image data sets were measured using the dice similarity coefficient (DSC). The evaluation was performed in 20 lung SBRT patients. Results: In our visual evaluation, the eighteen cases show good agreement between the deformed structures for the peak-inhale phase and the peak-exhale phase structures (more than 0.8 DSC value). In the evaluation of the DSC in-house software, averaged DSC values of GTV and lung, heart, spinal cord, stomach and body were 0.862 and 0.979, 0.932, 0.974, 0.860, 0.998, respectively. As the Resultof the registration using the MIM program in the two cases which had less than 0.7 DSC value when analyzed using the in-house software, the DSC value were improved to 0.8. The CT images in a case with low DSC value shows the tumor was surrounded by the structure with the similar CT values, which were the chest wall or the diaphragm. Conclusion: Not only a free-downloadable DIR software but also a commercial software may provide unexpected results and there is a possibility that the results would make us misjudge the treatment planning. Therefore, we recommend that a commissioning test of any DIR software should be performed before clinical use and we should understand the characteristics of the software

Use of the CT component of PET-CT to improve PET-MR registration: demonstration in soft-tissue sarcoma

International Nuclear Information System (INIS)

Somer, Edward J; Benatar, Nigel A; O'Doherty, Michael J; Smith, Mike A; Marsden, Paul K

2007-01-01

We have investigated improvements to PET-MR image registration offered by PET-CT scanning. Ten subjects with suspected soft-tissue sarcomas were scanned with an in-line PET-CT and a clinical MR scanner. PET to CT, CT to MR and PET to MR image registrations were performed using a rigid-body external marker technique and rigid and non-rigid voxel-similarity algorithms. PET-MR registration was also performed using transformations derived from the registration of CT to MR. The external marker technique gave fiducial registration errors of 2.1 mm, 5.1 mm and 5.3 mm for PET-CT, PET-MR and CT-MR registration. Target registration errors were 3.9 mm, 9.0 mm and 9.3 mm, respectively. Voxel-based algorithms were evaluated by measuring the distance between corresponding fiducials after registration. Registration errors of 6.4 mm, 14.5 mm and 9.5 mm, respectively, for PET-CT, PET-MR and CT-MR were observed for rigid-body registration while non-rigid registration gave errors of 6.8 mm, 16.3 mm and 7.6 mm for the same modality combinations. The application of rigid and non-rigid CT to MR transformations to accompanying PET data gives significantly reduced PET-MR errors of 10.0 mm and 8.5 mm, respectively. Visual comparison by two independent observers confirmed the improvement over direct PET-MR registration. We conclude that PET-MR registration can be more accurately and reliably achieved using the hybrid technique described than through direct rigid-body registration of PET to MR

Is Mandatory Prospective Trial Registration Working to Prevent Publication of Unregistered Trials and Selective Outcome Reporting? An Observational Study of Five Psychiatry Journals That Mandate Prospective Clinical Trial Registration.

Directory of Open Access Journals (Sweden)

Amelia Scott

.4% of the 181 the trials were prospectively registered and did not alter their POMs or the time frames at which they were measured. Prospective registration with no changes in POMs occurred more frequently with pharmaceutical funding.Although standards are in place to improve prospective registration and transparency in clinical trials, less than 15% of psychiatry trials were prospectively registered with no changes in POMs. Most trials were either not prospectively registered, changed POMs or the timeframes at some point after registration or changed participant numbers. Authors, journal editors and reviewers need to further efforts to highlight the value of prospective trial registration.

Toward adaptive radiotherapy for head and neck patients: Feasibility study on using CT-to-CBCT deformable registration for "dose of the day" calculations.

Science.gov (United States)

Veiga, Catarina; McClelland, Jamie; Moinuddin, Syed; Lourenço, Ana; Ricketts, Kate; Annkah, James; Modat, Marc; Ourselin, Sébastien; D'Souza, Derek; Royle, Gary

2014-03-01

The aim of this study was to evaluate the appropriateness of using computed tomography (CT) to cone-beam CT (CBCT) deformable image registration (DIR) for the application of calculating the "dose of the day" received by a head and neck patient. NiftyReg is an open-source registration package implemented in our institution. The affine registration uses a Block Matching-based approach, while the deformable registration is a GPU implementation of the popular B-spline Free Form Deformation algorithm. Two independent tests were performed to assess the suitability of our registrations methodology for "dose of the day" calculations in a deformed CT. A geometric evaluation was performed to assess the ability of the DIR method to map identical structures between the CT and CBCT datasets. Features delineated in the planning CT were warped and compared with features manually drawn on the CBCT. The authors computed the dice similarity coefficient (DSC), distance transformation, and centre of mass distance between features. A dosimetric evaluation was performed to evaluate the clinical significance of the registrations errors in the application proposed and to identify the limitations of the approximations used. Dose calculations for the same intensity-modulated radiation therapy plan on the deformed CT and replan CT were compared. Dose distributions were compared in terms of dose differences (DD), gamma analysis, target coverage, and dose volume histograms (DVHs). Doses calculated in a rigidly aligned CT and directly in an extended CBCT were also evaluated. A mean value of 0.850 in DSC was achieved in overlap between manually delineated and warped features, with the distance between surfaces being less than 2 mm on over 90% of the pixels. Deformable registration was clearly superior to rigid registration in mapping identical structures between the two datasets. The dose recalculated in the deformed CT is a good match to the dose calculated on a replan CT. The DD is smaller

Reducing uncertainties in volumetric image based deformable organ registration

International Nuclear Information System (INIS)

Liang, J.; Yan, D.

2003-01-01

Applying volumetric image feedback in radiotherapy requires image based deformable organ registration. The foundation of this registration is the ability of tracking subvolume displacement in organs of interest. Subvolume displacement can be calculated by applying biomechanics model and the finite element method to human organs manifested on the multiple volumetric images. The calculation accuracy, however, is highly dependent on the determination of the corresponding organ boundary points. Lacking sufficient information for such determination, uncertainties are inevitable--thus diminishing the registration accuracy. In this paper, a method of consuming energy minimization was developed to reduce these uncertainties. Starting from an initial selection of organ boundary point correspondence on volumetric image sets, the subvolume displacement and stress distribution of the whole organ are calculated and the consumed energy due to the subvolume displacements is computed accordingly. The corresponding positions of the initially selected boundary points are then iteratively optimized to minimize the consuming energy under geometry and stress constraints. In this study, a rectal wall delineated from patient CT image was artificially deformed using a computer simulation and utilized to test the optimization. Subvolume displacements calculated based on the optimized boundary point correspondence were compared to the true displacements, and the calculation accuracy was thereby evaluated. Results demonstrate that a significant improvement on the accuracy of the deformable organ registration can be achieved by applying the consuming energy minimization in the organ deformation calculation

MRI-based treatment planning with pseudo CT generated through atlas registration

International Nuclear Information System (INIS)

Uh, Jinsoo; Merchant, Thomas E.; Hua, Chiaho; Li, Yimei; Li, Xingyu

2014-01-01

Purpose: To evaluate the feasibility and accuracy of magnetic resonance imaging (MRI)-based treatment planning using pseudo CTs generated through atlas registration. Methods: A pseudo CT, providing electron density information for dose calculation, was generated by deforming atlas CT images previously acquired on other patients. The authors tested 4 schemes of synthesizing a pseudo CT from single or multiple deformed atlas images: use of a single arbitrarily selected atlas, arithmetic mean process using 6 atlases, and pattern recognition with Gaussian process (PRGP) using 6 or 12 atlases. The required deformation for atlas CT images was derived from a nonlinear registration of conjugated atlas MR images to that of the patient of interest. The contrasts of atlas MR images were adjusted by histogram matching to reduce the effect of different sets of acquisition parameters. For comparison, the authors also tested a simple scheme assigning the Hounsfield unit of water to the entire patient volume. All pseudo CT generating schemes were applied to 14 patients with common pediatric brain tumors. The image similarity of real patient-specific CT and pseudo CTs constructed by different schemes was compared. Differences in computation times were also calculated. The real CT in the treatment planning system was replaced with the pseudo CT, and the dose distribution was recalculated to determine the difference. Results: The atlas approach generally performed better than assigning a bulk CT number to the entire patient volume. Comparing atlas-based schemes, those using multiple atlases outperformed the single atlas scheme. For multiple atlas schemes, the pseudo CTs were similar to the real CTs (correlation coefficient, 0.787–0.819). The calculated dose distribution was in close agreement with the original dose. Nearly the entire patient volume (98.3%–98.7%) satisfied the criteria of chi-evaluation (<2% maximum dose and 2 mm range). The dose to 95% of the volume and the

MRI-based treatment planning with pseudo CT generated through atlas registration

Energy Technology Data Exchange (ETDEWEB)

Uh, Jinsoo, E-mail: jinsoo.uh@stjude.org; Merchant, Thomas E.; Hua, Chiaho [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States); Li, Yimei; Li, Xingyu [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States)

2014-05-15

Purpose: To evaluate the feasibility and accuracy of magnetic resonance imaging (MRI)-based treatment planning using pseudo CTs generated through atlas registration. Methods: A pseudo CT, providing electron density information for dose calculation, was generated by deforming atlas CT images previously acquired on other patients. The authors tested 4 schemes of synthesizing a pseudo CT from single or multiple deformed atlas images: use of a single arbitrarily selected atlas, arithmetic mean process using 6 atlases, and pattern recognition with Gaussian process (PRGP) using 6 or 12 atlases. The required deformation for atlas CT images was derived from a nonlinear registration of conjugated atlas MR images to that of the patient of interest. The contrasts of atlas MR images were adjusted by histogram matching to reduce the effect of different sets of acquisition parameters. For comparison, the authors also tested a simple scheme assigning the Hounsfield unit of water to the entire patient volume. All pseudo CT generating schemes were applied to 14 patients with common pediatric brain tumors. The image similarity of real patient-specific CT and pseudo CTs constructed by different schemes was compared. Differences in computation times were also calculated. The real CT in the treatment planning system was replaced with the pseudo CT, and the dose distribution was recalculated to determine the difference. Results: The atlas approach generally performed better than assigning a bulk CT number to the entire patient volume. Comparing atlas-based schemes, those using multiple atlases outperformed the single atlas scheme. For multiple atlas schemes, the pseudo CTs were similar to the real CTs (correlation coefficient, 0.787–0.819). The calculated dose distribution was in close agreement with the original dose. Nearly the entire patient volume (98.3%–98.7%) satisfied the criteria of chi-evaluation (<2% maximum dose and 2 mm range). The dose to 95% of the volume and the

Central research registration at Technical University of Denmark (DTU)

DEFF Research Database (Denmark)

Sand, Ane Ahrenkiel

Some five years ago, DTU switched from decentralized research registration, where researchers entered their publications into the DTU research repository themselves to centralized research registration, whereby library staff upload academic publications to the repository on behalf...... up the registration team, the configuration of the repository platform (Pure), the registration workflow and last but not least the results since DTU switched to centralized research registration....

Central Research Registration at Technical University of Denmark (DTU)

DEFF Research Database (Denmark)

Sand, Ane Ahrenkiel

Some five years ago, DTU switched from decentralized research registration, where researchers entered their publications into the DTU research repository themselves to centralized research registration, whereby library staff upload academic publications to the repository on behalf...... up the registration team, the configuration of the repository platform (Pure), the registration workflow and last but not least the results since DTU switched to centralized research registration....

Fuels Registration, Reporting, and Compliance Help

Science.gov (United States)

Information about the requirements for registration and health effects testing of new fuels or fuel additives and mandatory registration for fuels reporting and about mandatory reporting forms for parties regulated under EPA fuel programs.

The cadastral registration of the property right

Directory of Open Access Journals (Sweden)

D.-G. IONAȘ

2017-12-01

Full Text Available Real rights are subjective patrimonial rights which provide the holder with the right to directly exercise certain prerogatives over a determined good. Real rights over immobile goods, registered in the cadastral register are called tabular rights. Cadastral registration is that certain form of registration by which a real right over an immobile good is acquired, changed or ended, from the time de registration request is filed. At this time, registration in the cadastral register provides the opposability effect, as the constitutive effect is suspended until the cadastral works are finalized and new cadastral registers are created for each administrative unit.

Pain education in pre-registration professional health courses: a protocol for a scoping review.

Science.gov (United States)

Thompson, Kate; Milligan, James; Johnson, Mark I; Briggs, Michelle

2016-07-18

Pain is a global health concern causing significant health and social problems with evidence that patients experiencing pain are receiving inadequate care. The content of pain education in pre-registration professional health courses is thought to be lacking both in the UK and internationally which is unacceptable considering the prevalence of pain. Evaluating the effect of education is complex in that the outcome (improved healthcare) is some distance from the educational approach. Best evidence medical education has been proposed as a continuum between 'opinion-based teaching' and 'evidence-based teaching'. Searching for evidence to inform best practice in health education is complex. A scoping review provides a practical and comprehensive strategy to locate and synthesise literature of varied methodology including reports from a variety of sources. The aim of this article is to describe a protocol for a scoping review that will locate, map and report research, guidelines and policies for pain education in pre-registration professional health courses. The extent, range and nature of reports will be examined, and where possible titles for potential systematic review will be identified. Reports will be included for review that are directly relevant to the development of the pain curriculum in pre-registration professional health courses, eg nursing, medicine, physiotherapy. The search strategy will identify reports that include [pain] AND [pre-registration education or curriculum] AND [health professionals] in the title or abstract. Two authors will independently screen retrieved studies against eligibility criteria. A numerical analysis regarding the extent, nature and distribution of reports will be given along with a narrative synthesis to describe characteristics of relevant reports. Formal ethical approval was not required to undertake this scoping review. Findings will be published in scientific peer-reviewed journals and via conference presentations

4D co-registration of X-ray and MR-mammograms: initial clinical results and potential incremental diagnostic value.

Science.gov (United States)

Dietzel, Matthias; Hopp, Torsten; Ruiter, Nicole V; Kaiser, Clemens G; Kaiser, Werner A; Baltzer, Pascal A

2015-01-01

4D co-registration of X-ray- and MR-mammograms (XM and MM) is a new method of image fusion. The present study aims to evaluate its clinical feasibility, radiological accuracy, and potential clinical value. XM and MM of 25 patients were co-registered. Results were evaluated by a blinded reader. Precision of the 4D co-registration was "very good" (mean-score [ms]=7), and lesions were "easier to delineate" (ms=5). In 88.8%, "relevant additional diagnostic information" was present, accounting for a more "confident diagnosis" in 76% (ms=5). 4D co-registration is feasible, accurate, and of potential clinical value. Copyright © 2015 Elsevier Inc. All rights reserved.

Consistency and accuracy of diagnostic cancer codes generated by automated registration: comparison with manual registration

Directory of Open Access Journals (Sweden)

Codazzi Tiziana

2006-09-01

Full Text Available Abstract Background Automated procedures are increasingly used in cancer registration, and it is important that the data produced are systematically checked for consistency and accuracy. We evaluated an automated procedure for cancer registration adopted by the Lombardy Cancer Registry in 1997, comparing automatically-generated diagnostic codes with those produced manually over one year (1997. Methods The automatically generated cancer cases were produced by Open Registry algorithms. For manual registration, trained staff consulted clinical records, pathology reports and death certificates. The social security code, present and checked in both databases in all cases, was used to match the files in the automatic and manual databases. The cancer cases generated by the two methods were compared by manual revision. Results The automated procedure generated 5027 cases: 2959 (59% were accepted automatically and 2068 (41% were flagged for manual checking. Among the cases accepted automatically, discrepancies in data items (surname, first name, sex and date of birth constituted 8.5% of cases, and discrepancies in the first three digits of the ICD-9 code constituted 1.6%. Among flagged cases, cancers of female genital tract, hematopoietic system, metastatic and ill-defined sites, and oropharynx predominated. The usual reasons were use of specific vs. generic codes, presence of multiple primaries, and use of extranodal vs. nodal codes for lymphomas. The percentage of automatically accepted cases ranged from 83% for breast and thyroid cancers to 13% for metastatic and ill-defined cancer sites. Conclusion Since 59% of cases were accepted automatically and contained relatively few, mostly trivial discrepancies, the automatic procedure is efficient for routine case generation effectively cutting the workload required for routine case checking by this amount. Among cases not accepted automatically, discrepancies were mainly due to variations in coding practice.

Three dimensional image alignment, registration and fusion

International Nuclear Information System (INIS)

Treves, S.T.; Mitchell, K.D.; Habboush, I.H.

1998-01-01

Combined assessment of three dimensional anatomical and functional images (SPECT, PET, MRI, CT) is useful to determine the nature and extent of lesions in many parts of the body. Physicians principally rely on their spatial sense of mentally re-orient and overlap images obtained with different imaging modalities. Objective methods that enable easy and intuitive image registration can help the physician arrive at more optimal diagnoses and better treatment decisions. This review describes a simple, intuitive and robust image registration approach developed in our laboratory. It differs from most other registration techniques in that it allows the user to incorporate all of the available information within the images in the registration process. This method takes full advantage of the ability of knowledgeable operators to achieve image registration and fusion using an intuitive interactive visual approach. It can register images accurately and quickly without the use of elaborate mathematical modeling or optimization techniques. The method provides the operator with tools to manipulate images in three dimensions, including visual feedback techniques to assess the accuracy of registration (grids, overlays, masks, and fusion of images in different colors). Its application is not limited to brain imaging and can be applied to images from any region in the body. The overall effect is a registration algorithm that is easy to implement and can achieve accuracy on the order of one pixel

Sulcal set optimization for cortical surface registration.

Science.gov (United States)

Joshi, Anand A; Pantazis, Dimitrios; Li, Quanzheng; Damasio, Hanna; Shattuck, David W; Toga, Arthur W; Leahy, Richard M

2010-04-15

Flat mapping based cortical surface registration constrained by manually traced sulcal curves has been widely used for inter subject comparisons of neuroanatomical data. Even for an experienced neuroanatomist, manual sulcal tracing can be quite time consuming, with the cost increasing with the number of sulcal curves used for registration. We present a method for estimation of an optimal subset of size N(C) from N possible candidate sulcal curves that minimizes a mean squared error metric over all combinations of N(C) curves. The resulting procedure allows us to estimate a subset with a reduced number of curves to be traced as part of the registration procedure leading to optimal use of manual labeling effort for registration. To minimize the error metric we analyze the correlation structure of the errors in the sulcal curves by modeling them as a multivariate Gaussian distribution. For a given subset of sulci used as constraints in surface registration, the proposed model estimates registration error based on the correlation structure of the sulcal errors. The optimal subset of constraint curves consists of the N(C) sulci that jointly minimize the estimated error variance for the subset of unconstrained curves conditioned on the N(C) constraint curves. The optimal subsets of sulci are presented and the estimated and actual registration errors for these subsets are computed. Copyright 2009 Elsevier Inc. All rights reserved.

An efficient strategy based on an individualized selection of registration methods. Application to the coregistration of MR and SPECT images in neuro-oncology

International Nuclear Information System (INIS)

Tacchella, Jean-Marc; Lefort, Muriel; Habert, Marie-Odile; Yeni, Nathanaëlle; Kas, Aurélie; Frouin, Frédérique; Roullot, Elodie; Cohen, Mike-Ely; Guillevin, Rémy; Petrirena, Grégorio; Delattre, Jean-Yves

2014-01-01

An efficient registration strategy is described that aims to help solve delicate medical imaging registration problems. It consists of running several registration methods for each dataset and selecting the best one for each specific dataset, according to an evaluation criterion. Finally, the quality of the registration results, obtained with the best method, is visually scored by an expert as excellent, correct or poor. The strategy was applied to coregister Technetium-99m Sestamibi SPECT and MRI data in the framework of a follow-up protocol in patients with high grade gliomas receiving antiangiogenic therapy. To adapt the strategy to this clinical context, a robust semi-automatic evaluation criterion based on the physiological uptake of the Sestamibi tracer was defined. A panel of eighteen multimodal registration algorithms issued from BrainVisa, SPM or AIR software environments was systematically applied to the clinical database composed of sixty-two datasets. According to the expert visual validation, this new strategy provides 85% excellent registrations, 12% correct ones and only 3% poor ones. These results compare favorably to the ones obtained by the globally most efficient registration method over the whole database, for which only 61% of excellent registration results have been reported. Thus the registration strategy in its current implementation proves to be suitable for clinical application. (paper)

New York Power Authority`s energy-efficient refigerator program for the New York City Housing Authority - savings evaluation

Energy Technology Data Exchange (ETDEWEB)

Pratt, R.G.; Miller, J.D.

1997-09-01

The New York Power Authority (NYPA) and the New York City Housing Authority (NYCHA) are replacing refrigerators in New York City public housing with new, highly energy-efficient models over a five-year period. This report describes the analysis of the energy cost savings achieved through the replacement of 20,000 refrigerators in 1996, the first year of the NYPA/NYCHA program. The NYPA/NYCHA project serves as the lynchpin of a larger program designed to offer energy-efficient appliances to housing authorities across the country. The national program is a partnership between the U.S. Department of Energy (DOE) and the Consortium for Energy Efficiency (CEE). Starting with the 1997 refrigerator contract, this program invites other housing authorities to join NYPA in its volume purchase of energy-efficient refrigerators, at the same price and terms available to NYPA. Through these volume purchases, DOE`s ENERGY STAR{reg_sign} Partnerships program hopes to encourage appliance manufacturers to bring more efficient appliances to the market and to provide volume purchasers with the per-unit price savings of a bulk purchaser. DOE asked the Pacific Northwest National Laboratory (PNNL) to establish a protocol for evaluating the savings achieved with the NYPA refrigerators. That protocol is summarized in this report.

Prostate multimodality image registration based on B-splines and quadrature local energy.

Science.gov (United States)

Mitra, Jhimli; Martí, Robert; Oliver, Arnau; Lladó, Xavier; Ghose, Soumya; Vilanova, Joan C; Meriaudeau, Fabrice

2012-05-01

Needle biopsy of the prostate is guided by Transrectal Ultrasound (TRUS) imaging. The TRUS images do not provide proper spatial localization of malignant tissues due to the poor sensitivity of TRUS to visualize early malignancy. Magnetic Resonance Imaging (MRI) has been shown to be sensitive for the detection of early stage malignancy, and therefore, a novel 2D deformable registration method that overlays pre-biopsy MRI onto TRUS images has been proposed. The registration method involves B-spline deformations with Normalized Mutual Information (NMI) as the similarity measure computed from the texture images obtained from the amplitude responses of the directional quadrature filter pairs. Registration accuracy of the proposed method is evaluated by computing the Dice Similarity coefficient (DSC) and 95% Hausdorff Distance (HD) values for 20 patients prostate mid-gland slices and Target Registration Error (TRE) for 18 patients only where homologous structures are visible in both the TRUS and transformed MR images. The proposed method and B-splines using NMI computed from intensities provide average TRE values of 2.64 ± 1.37 and 4.43 ± 2.77 mm respectively. Our method shows statistically significant improvement in TRE when compared with B-spline using NMI computed from intensities with Student's t test p = 0.02. The proposed method shows 1.18 times improvement over thin-plate splines registration with average TRE of 3.11 ± 2.18 mm. The mean DSC and the mean 95% HD values obtained with the proposed method of B-spline with NMI computed from texture are 0.943 ± 0.039 and 4.75 ± 2.40 mm respectively. The texture energy computed from the quadrature filter pairs provides better registration accuracy for multimodal images than raw intensities. Low TRE values of the proposed registration method add to the feasibility of it being used during TRUS-guided biopsy.

Markerless registration for image guided surgery. Preoperative image, intraoperative video image, and patient

International Nuclear Information System (INIS)

Kihara, Tomohiko; Tanaka, Yuko

1998-01-01

Real-time and volumetric acquisition of X-ray CT, MR, and SPECT is the latest trend of the medical imaging devices. A clinical challenge is to use these multi-modality volumetric information complementary on patient in the entire diagnostic and surgical processes. The intraoperative image and patient integration intents to establish a common reference frame by image in diagnostic and surgical processes. This provides a quantitative measure during surgery, for which we have been relied mostly on doctors' skills and experiences. The intraoperative image and patient integration involves various technologies, however, we think one of the most important elements is the development of markerless registration, which should be efficient and applicable to the preoperative multi-modality data sets, intraoperative image, and patient. We developed a registration system which integrates preoperative multi-modality images, intraoperative video image, and patient. It consists of a real-time registration of video camera for intraoperative use, a markerless surface sampling matching of patient and image, our previous works of markerless multi-modality image registration of X-ray CT, MR, and SPECT, and an image synthesis on video image. We think these techniques can be used in many applications which involve video camera like devices such as video camera, microscope, and image Intensifier. (author)

Clinical leadership in pre-registration nursing programmes--an international literature review.

Science.gov (United States)

Brown, Angela; Crookes, Patrick; Dewing, Jan

2015-01-01

Clinical leadership and the safety, quality and efficiency of patient/client care are inextricably linked in government reports, major inquiries and the professional literature. This review explores the literature on clinical leadership development within pre-registration nursing programmes. The literature retrieved from a scoping review was evaluated to identify what is already published on the development of clinical leadership within pre-registration nursing programmes. Twenty-seven publications matched the inclusion criteria and were included in this review, 14 journal articles, one thesis and 11 chapters within one book were analysed and three themes were identified: clinical leadership; curriculum content and pedagogy. RESULTS AND MAIN OUTCOMES: This review identified a paucity of literature specifically relating to clinical leadership and pre-registration nursing programmes and what is available is inconclusive and unconvincing. Academics, curriculum development leaders and accreditation bodies have a responsibility to influence how nurses are prepared for the profession as such clinical leadership and the new graduate should be considered an area of greater importance.

Progressive attenuation fields: Fast 2D-3D image registration without precomputation

International Nuclear Information System (INIS)

Rohlfing, Torsten; Russakoff, Daniel B.; Denzler, Joachim; Mori, Kensaku; Maurer, Calvin R. Jr.

2005-01-01

Computation of digitally reconstructed radiograph (DRR) images is the rate-limiting step in most current intensity-based algorithms for the registration of three-dimensional (3D) images to two-dimensional (2D) projection images. This paper introduces and evaluates the progressive attenuation field (PAF), which is a new method to speed up DRR computation. A PAF is closely related to an attenuation field (AF). A major difference is that a PAF is constructed on the fly as the registration proceeds; it does not require any precomputation time, nor does it make any prior assumptions of the patient pose or limit the permissible range of patient motion. A PAF effectively acts as a cache memory for projection values once they are computed, rather than as a lookup table for precomputed projections like standard AFs. We use a cylindrical attenuation field parametrization, which is better suited for many medical applications of 2D-3D registration than the usual two-plane parametrization. The computed attenuation values are stored in a hash table for time-efficient storage and access. Using clinical gold-standard spine image data sets from five patients, we demonstrate consistent speedups of intensity-based 2D-3D image registration using PAF DRRs by a factor of 10 over conventional ray casting DRRs with no decrease of registration accuracy or robustness

Quantitative evaluation of an image registration method for a NIPAM gel dosimeter

Science.gov (United States)

Chang, Yuan-Jen; Yao, Chun-Hsu; Wu, Jay; Hsieh, Bor-Tsung; Tsang, Yuk-Wah; Chen, Chin-Hsing

2015-06-01

One of the problems in obtaining quality results is image registration when a gel dosimeter is used in conjunction with optical computed tomography (CT). This study proposes a passive alignment mechanism to obtain a precisely measured dose map. A holder plate with two pin-hole pairs is placed on the gel container cap. These two pin-hole pairs attach the gel container to the vertical shaft and can be precisely aligned with the rotation center of the vertical shaft at any time. Accordingly, a better reconstructed image quality is obtained. After obtaining a precisely measured dose map, the scale invariant feature transform (SIFT)-flow algorithm is utilized as an image registration method to align the treatment plan software (TPS) image with the measured dose map image. The results show that the gamma pass rate for the single-field irradiation increases from 83.39% to 94.03% when the algorithm is applied. And the gamma pass rate for the five-field irradiation treatment plan increases from 87.36% to 94.34%. The translation, scaling, and rotation occurring in the dose map image constructed using an optical CT scanner are also aligned with those in the TPS image using the SIFT-flow algorithm. Accordingly, improved gamma comparison results and a higher gamma pass rate are obtained.

Improving supervised classification accuracy using non-rigid multimodal image registration: detecting prostate cancer

Science.gov (United States)

Chappelow, Jonathan; Viswanath, Satish; Monaco, James; Rosen, Mark; Tomaszewski, John; Feldman, Michael; Madabhushi, Anant

2008-03-01

Computer-aided diagnosis (CAD) systems for the detection of cancer in medical images require precise labeling of training data. For magnetic resonance (MR) imaging (MRI) of the prostate, training labels define the spatial extent of prostate cancer (CaP); the most common source for these labels is expert segmentations. When ancillary data such as whole mount histology (WMH) sections, which provide the gold standard for cancer ground truth, are available, the manual labeling of CaP can be improved by referencing WMH. However, manual segmentation is error prone, time consuming and not reproducible. Therefore, we present the use of multimodal image registration to automatically and accurately transcribe CaP from histology onto MRI following alignment of the two modalities, in order to improve the quality of training data and hence classifier performance. We quantitatively demonstrate the superiority of this registration-based methodology by comparing its results to the manual CaP annotation of expert radiologists. Five supervised CAD classifiers were trained using the labels for CaP extent on MRI obtained by the expert and 4 different registration techniques. Two of the registration methods were affi;ne schemes; one based on maximization of mutual information (MI) and the other method that we previously developed, Combined Feature Ensemble Mutual Information (COFEMI), which incorporates high-order statistical features for robust multimodal registration. Two non-rigid schemes were obtained by succeeding the two affine registration methods with an elastic deformation step using thin-plate splines (TPS). In the absence of definitive ground truth for CaP extent on MRI, classifier accuracy was evaluated against 7 ground truth surrogates obtained by different combinations of the expert and registration segmentations. For 26 multimodal MRI-WMH image pairs, all four registration methods produced a higher area under the receiver operating characteristic curve compared to that

Mammogram CAD, hybrid registration and iconic analysis

Science.gov (United States)

Boucher, A.; Cloppet, F.; Vincent, N.

2013-03-01

This paper aims to develop a computer aided diagnosis (CAD) based on a two-step methodology to register and analyze pairs of temporal mammograms. The concept of "medical file", including all the previous medical information on a patient, enables joint analysis of different acquisitions taken at different times, and the detection of significant modifications. The developed registration method aims to superimpose at best the different anatomical structures of the breast. The registration is designed in order to get rid of deformation undergone by the acquisition process while preserving those due to breast changes indicative of malignancy. In order to reach this goal, a referent image is computed from control points based on anatomical features that are extracted automatically. Then the second image of the couple is realigned on the referent image, using a coarse-to-fine approach according to expert knowledge that allows both rigid and non-rigid transforms. The joint analysis detects the evolution between two images representing the same scene. In order to achieve this, it is important to know the registration error limits in order to adapt the observation scale. The approach used in this paper is based on an image sparse representation. Decomposed in regular patterns, the images are analyzed under a new angle. The evolution detection problem has many practical applications, especially in medical images. The CAD is evaluated using recall and precision of differences in mammograms.

Deformable registration of the planning image (kVCT) and the daily images (MVCT) for adaptive radiation therapy

International Nuclear Information System (INIS)

Lu Weiguo; Olivera, Gustavo H; Chen, Quan; Ruchala, Kenneth J; Haimerl, Jason; Meeks, Sanford L; Langen, Katja M; Kupelian, Patrick A

2006-01-01

The incorporation of daily images into the radiotherapy process leads to adaptive radiation therapy (ART), in which the treatment is evaluated periodically and the plan is adaptively modified for the remaining course of radiotherapy. Deformable registration between the planning image and the daily images is a key component of ART. In this paper, we report our researches on deformable registration between the planning kVCT and the daily MVCT image sets. The method is based on a fast intensity-based free-form deformable registration technique. Considering the noise and contrast resolution differences between the kVCT and the MVCT, an 'edge-preserving smoothing' is applied to the MVCT image prior to the deformable registration process. We retrospectively studied daily MVCT images from commercial TomoTherapy machines from different clinical centers. The data set includes five head-neck cases, one pelvis case, two lung cases and one prostate case. Each case has one kVCT image and 20-40 MVCT images. We registered the MVCT images with their corresponding kVCT image. The similarity measures and visual inspections of contour matches by physicians validated this technique. The applications of deformable registration in ART, including 'deformable dose accumulation', 'automatic re-contouring' and 'tumour growth/regression evaluation' throughout the course of radiotherapy are also studied

Toward adaptive radiotherapy for head and neck patients: Feasibility study on using CT-to-CBCT deformable registration for “dose of the day” calculations

Energy Technology Data Exchange (ETDEWEB)

Veiga, Catarina, E-mail: catarina.veiga.11@ucl.ac.uk; Lourenço, Ana; Ricketts, Kate; Annkah, James; Royle, Gary [Radiation Physics Group, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom); McClelland, Jamie; Modat, Marc; Ourselin, Sébastien [Centre for Medical Image Computing, Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom); Moinuddin, Syed [Department of Radiotherapy, University College London Hospital, London NW1 2BU (United Kingdom); D’Souza, Derek [Department of Radiotherapy Physics, University College London Hospital, London NW1 2PG (United Kingdom)

2014-03-15

Purpose: The aim of this study was to evaluate the appropriateness of using computed tomography (CT) to cone-beam CT (CBCT) deformable image registration (DIR) for the application of calculating the “dose of the day” received by a head and neck patient. Methods: NiftyReg is an open-source registration package implemented in our institution. The affine registration uses a Block Matching-based approach, while the deformable registration is a GPU implementation of the popular B-spline Free Form Deformation algorithm. Two independent tests were performed to assess the suitability of our registrations methodology for “dose of the day” calculations in a deformed CT. A geometric evaluation was performed to assess the ability of the DIR method to map identical structures between the CT and CBCT datasets. Features delineated in the planning CT were warped and compared with features manually drawn on the CBCT. The authors computed the dice similarity coefficient (DSC), distance transformation, and centre of mass distance between features. A dosimetric evaluation was performed to evaluate the clinical significance of the registrations errors in the application proposed and to identify the limitations of the approximations used. Dose calculations for the same intensity-modulated radiation therapy plan on the deformed CT and replan CT were compared. Dose distributions were compared in terms of dose differences (DD), gamma analysis, target coverage, and dose volume histograms (DVHs). Doses calculated in a rigidly aligned CT and directly in an extended CBCT were also evaluated. Results: A mean value of 0.850 in DSC was achieved in overlap between manually delineated and warped features, with the distance between surfaces being less than 2 mm on over 90% of the pixels. Deformable registration was clearly superior to rigid registration in mapping identical structures between the two datasets. The dose recalculated in the deformed CT is a good match to the dose calculated on

Toward adaptive radiotherapy for head and neck patients: Feasibility study on using CT-to-CBCT deformable registration for “dose of the day” calculations

International Nuclear Information System (INIS)

Veiga, Catarina; Lourenço, Ana; Ricketts, Kate; Annkah, James; Royle, Gary; McClelland, Jamie; Modat, Marc; Ourselin, Sébastien; Moinuddin, Syed; D’Souza, Derek

2014-01-01

Purpose: The aim of this study was to evaluate the appropriateness of using computed tomography (CT) to cone-beam CT (CBCT) deformable image registration (DIR) for the application of calculating the “dose of the day” received by a head and neck patient. Methods: NiftyReg is an open-source registration package implemented in our institution. The affine registration uses a Block Matching-based approach, while the deformable registration is a GPU implementation of the popular B-spline Free Form Deformation algorithm. Two independent tests were performed to assess the suitability of our registrations methodology for “dose of the day” calculations in a deformed CT. A geometric evaluation was performed to assess the ability of the DIR method to map identical structures between the CT and CBCT datasets. Features delineated in the planning CT were warped and compared with features manually drawn on the CBCT. The authors computed the dice similarity coefficient (DSC), distance transformation, and centre of mass distance between features. A dosimetric evaluation was performed to evaluate the clinical significance of the registrations errors in the application proposed and to identify the limitations of the approximations used. Dose calculations for the same intensity-modulated radiation therapy plan on the deformed CT and replan CT were compared. Dose distributions were compared in terms of dose differences (DD), gamma analysis, target coverage, and dose volume histograms (DVHs). Doses calculated in a rigidly aligned CT and directly in an extended CBCT were also evaluated. Results: A mean value of 0.850 in DSC was achieved in overlap between manually delineated and warped features, with the distance between surfaces being less than 2 mm on over 90% of the pixels. Deformable registration was clearly superior to rigid registration in mapping identical structures between the two datasets. The dose recalculated in the deformed CT is a good match to the dose calculated on

17 CFR 240.15Bc3-1 - Withdrawal from registration of municipal securities dealers.

Science.gov (United States)

2010-04-01

... update any inaccurate information. (b) Every notice of withdrawal from registration as a municipal... Depository (operated by the Financial Industry Regulatory Authority, Inc.) in accordance with applicable... public interest or for the protection of investors, or within such shorter period of time as the...

Language proficiency and nursing registration.

Science.gov (United States)

Müller, Amanda

2016-02-01

This discussion paper focuses on English proficiency standards for nursing registration in Australia, how Australia has dealt with the issue of language proficiency, and the factors which have led to the establishment of the current language standards. Also, this paper will provide a comparison of the two language tests that are currently accepted in Australia (OET and IELTS), including the appropriateness of these tests and the minimum standards used. The paper will also examine the use of educational background as an indicator of language proficiency. Finally, communication-based complaints in the post-registration environment will be explored, and some discussion will be provided about why pre-registration measures might have failed to prevent such problematic situations from occurring. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inverse consistent non-rigid image registration based on robust point set matching

Science.gov (United States)

2014-01-01

Background Robust point matching (RPM) has been extensively used in non-rigid registration of images to robustly register two sets of image points. However, except for the location at control points, RPM cannot estimate the consistent correspondence between two images because RPM is a unidirectional image matching approach. Therefore, it is an important issue to make an improvement in image registration based on RPM. Methods In our work, a consistent image registration approach based on the point sets matching is proposed to incorporate the property of inverse consistency and improve registration accuracy. Instead of only estimating the forward transformation between the source point sets and the target point sets in state-of-the-art RPM algorithms, the forward and backward transformations between two point sets are estimated concurrently in our algorithm. The inverse consistency constraints are introduced to the cost function of RPM and the fuzzy correspondences between two point sets are estimated based on both the forward and backward transformations simultaneously. A modified consistent landmark thin-plate spline registration is discussed in detail to find the forward and backward transformations during the optimization of RPM. The similarity of image content is also incorporated into point matching in order to improve image matching. Results Synthetic data sets, medical images are employed to demonstrate and validate the performance of our approach. The inverse consistent errors of our algorithm are smaller than RPM. Especially, the topology of transformations is preserved well for our algorithm for the large deformation between point sets. Moreover, the distance errors of our algorithm are similar to that of RPM, and they maintain a downward trend as whole, which demonstrates the convergence of our algorithm. The registration errors for image registrations are evaluated also. Again, our algorithm achieves the lower registration errors in same iteration number

Line-Based Registration of Panoramic Images and LiDAR Point Clouds for Mobile Mapping

Directory of Open Access Journals (Sweden)

Tingting Cui

2016-12-01

Full Text Available For multi-sensor integrated systems, such as the mobile mapping system (MMS, data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and LiDAR, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a LiDAR point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D LiDAR scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the LiDAR datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable.

Slice-to-Volume Nonrigid Registration of Histological Sections to MR Images of the Human Brain

Science.gov (United States)

Osechinskiy, Sergey; Kruggel, Frithjof

2011-01-01

Registration of histological images to three-dimensional imaging modalities is an important step in quantitative analysis of brain structure, in architectonic mapping of the brain, and in investigation of the pathology of a brain disease. Reconstruction of histology volume from serial sections is a well-established procedure, but it does not address registration of individual slices from sparse sections, which is the aim of the slice-to-volume approach. This study presents a flexible framework for intensity-based slice-to-volume nonrigid registration algorithms with a geometric transformation deformation field parametrized by various classes of spline functions: thin-plate splines (TPS), Gaussian elastic body splines (GEBS), or cubic B-splines. Algorithms are applied to cross-modality registration of histological and magnetic resonance images of the human brain. Registration performance is evaluated across a range of optimization algorithms and intensity-based cost functions. For a particular case of histological data, best results are obtained with a TPS three-dimensional (3D) warp, a new unconstrained optimization algorithm (NEWUOA), and a correlation-coefficient-based cost function. PMID:22567290

Slice-to-Volume Nonrigid Registration of Histological Sections to MR Images of the Human Brain

Directory of Open Access Journals (Sweden)

Sergey Osechinskiy

2011-01-01

Full Text Available Registration of histological images to three-dimensional imaging modalities is an important step in quantitative analysis of brain structure, in architectonic mapping of the brain, and in investigation of the pathology of a brain disease. Reconstruction of histology volume from serial sections is a well-established procedure, but it does not address registration of individual slices from sparse sections, which is the aim of the slice-to-volume approach. This study presents a flexible framework for intensity-based slice-to-volume nonrigid registration algorithms with a geometric transformation deformation field parametrized by various classes of spline functions: thin-plate splines (TPS, Gaussian elastic body splines (GEBS, or cubic B-splines. Algorithms are applied to cross-modality registration of histological and magnetic resonance images of the human brain. Registration performance is evaluated across a range of optimization algorithms and intensity-based cost functions. For a particular case of histological data, best results are obtained with a TPS three-dimensional (3D warp, a new unconstrained optimization algorithm (NEWUOA, and a correlation-coefficient-based cost function.

Mass Preserving Registration for lung CT

DEFF Research Database (Denmark)

Gorbunova, Vladlena; Lo, Pechin Chien Pau; Loeve, Martin

2009-01-01

intensities due to differences in inspiration level, we propose to adjust the intensity of lung tissue according to the local expansion or compression. An image registration method without intensity adjustment is compared to the proposed method. Both approaches are evaluated on a set of 10 pairs of expiration...... and inspiration CT scans of children with cystic fibrosis lung disease. The proposed method with mass preserving adjustment results in significantly better alignment of the vessel trees. Analysis of local volume change for regions with trapped air compared to normally ventilated regions revealed larger...

Overlay improvement by exposure map based mask registration optimization

Science.gov (United States)

Shi, Irene; Guo, Eric; Chen, Ming; Lu, Max; Li, Gordon; Li, Rivan; Tian, Eric

2015-03-01

Along with the increased miniaturization of semiconductor electronic devices, the design rules of advanced semiconductor devices shrink dramatically. [1] One of the main challenges of lithography step is the layer-to-layer overlay control. Furthermore, DPT (Double Patterning Technology) has been adapted for the advanced technology node like 28nm and 14nm, corresponding overlay budget becomes even tighter. [2][3] After the in-die mask registration (pattern placement) measurement is introduced, with the model analysis of a KLA SOV (sources of variation) tool, it's observed that registration difference between masks is a significant error source of wafer layer-to-layer overlay at 28nm process. [4][5] Mask registration optimization would highly improve wafer overlay performance accordingly. It was reported that a laser based registration control (RegC) process could be applied after the pattern generation or after pellicle mounting and allowed fine tuning of the mask registration. [6] In this paper we propose a novel method of mask registration correction, which can be applied before mask writing based on mask exposure map, considering the factors of mask chip layout, writing sequence, and pattern density distribution. Our experiment data show if pattern density on the mask keeps at a low level, in-die mask registration residue error in 3sigma could be always under 5nm whatever blank type and related writer POSCOR (position correction) file was applied; it proves random error induced by material or equipment would occupy relatively fixed error budget as an error source of mask registration. On the real production, comparing the mask registration difference through critical production layers, it could be revealed that registration residue error of line space layers with higher pattern density is always much larger than the one of contact hole layers with lower pattern density. Additionally, the mask registration difference between layers with similar pattern density

48 CFR 52.204-7 - Central Contractor Registration.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Central Contractor....204-7 Central Contractor Registration. As prescribed in 4.1105, use the following clause: Central Contractor Registration (APR 2008) (a) Definitions. As used in this clause— Central Contractor Registration...

Pesticide authorization in the EU-environment unprotected?

Science.gov (United States)

Stehle, Sebastian; Schulz, Ralf

2015-12-01

Pesticides constitute an integral part of high-intensity European agriculture. Prior to their authorization, a highly elaborated environmental risk assessment is mandatory according to EU pesticide legislation, i.e., Regulation (EC) No. 1107/2009. However, no field data-based evaluation of the risk assessment outcome, i.e., the regulatory acceptable concentrations (RACs), and therefore of the overall protectiveness of EU pesticide regulations exists. We conducted here a comprehensive meta-analysis using peer-reviewed literature on agricultural insecticide concentrations in EU surface waters and evaluated associated risks using the RACs derived from official European pesticide registration documents. As a result, 44.7 % of the 1566 cases of measured insecticide concentrations (MICs) in EU surface waters exceeded their respective RACs. It follows that current EU pesticide regulations do not protect the aquatic environment and that insecticides threaten aquatic biodiversity. RAC exceedances were significantly higher for insecticides authorized using conservative tier-I RACs and for more recently developed insecticide classes, i.e., pyrethroids. In addition, we identified higher risks, e.g., for smaller surface waters that are specifically considered in the regulatory risk assessment schemes. We illustrate the shortcomings of the EU regulatory risk assessment using two case studies that contextualize the respective risk assessment outcomes to field exposure. Overall, our meta-analysis challenges the field relevance and protectiveness of the regulatory environmental risk assessment conducted for pesticide authorization in the EU and indicates that critical revisions of related pesticide regulations and effective mitigation measures are urgently needed to substantially reduce the environmental risks arising from agricultural insecticide use.

Optimal registration conditions for tooth EPR dosimetry at low accumulated dose

International Nuclear Information System (INIS)

Galtsev, V.E.; Galtseva, E.V.; Lebedev, Y.S.

1997-01-01

The spectrum registration under rapid passage conditions (the second harmonic phase quadrature of the absorption signal) allows one to enhance substantially the sensitivity of tooth enamel and bone EPR dosimetry at a low accumulated dose. In the present work the dependencies of the radiation and background signals on EPR spectrometer parameters are described and the optimal conditions in RPM for EPR dosimetry are obtained. (Author)

Surface-to-surface registration using level sets

DEFF Research Database (Denmark)

Hansen, Mads Fogtmann; Erbou, Søren G.; Vester-Christensen, Martin

2007-01-01

This paper presents a general approach for surface-to-surface registration (S2SR) with the Euclidean metric using signed distance maps. In addition, the method is symmetric such that the registration of a shape A to a shape B is identical to the registration of the shape B to the shape A. The S2SR...... problem can be approximated by the image registration (IR) problem of the signed distance maps (SDMs) of the surfaces confined to some narrow band. By shrinking the narrow bands around the zero level sets the solution to the IR problem converges towards the S2SR problem. It is our hypothesis...... that this approach is more robust and less prone to fall into local minima than ordinary surface-to-surface registration. The IR problem is solved using the inverse compositional algorithm. In this paper, a set of 40 pelvic bones of Duroc pigs are registered to each other w.r.t. the Euclidean transformation...

Contacts in the Office of Pesticide Programs, Registration Division

Science.gov (United States)

The Registration Division (RD) is responsible product registrations, amendments, registrations, tolerances, experimental use permits, and emergency exemptions for conventional chemical pesticides. Find contacts in this division.

Endorsement of the CONSORT statement by high-impact medical journals in China: a survey of instructions for authors and published papers.

Directory of Open Access Journals (Sweden)

Xiao-qian Li

Full Text Available BACKGROUND: The CONSORT Statement is a reporting guideline for authors when reporting randomized controlled trials (RCTs. It offers a standard way for authors to prepare RCT reports. It has been endorsed by many high-impact medical journals and by international editorial groups. This study was conducted to assess the endorsement of the CONSORT Statement by high-impact medical journals in China by reviewing their instructions for authors. METHODOLOGY/PRINCIPAL FINDINGS: A total of 200 medical journals were selected according to the Chinese Science and Technology Journal Citation Reports, 195 of which publish clinical research papers. Their instructions for authors were reviewed and all texts mentioning the CONSORT Statement or CONSORT extension papers were extracted. Any mention of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URM developed by the International Committee of Medical Journal Editors (ICMJE or 'clinical trial registration' was also extracted. For journals endorsing the CONSORT Statement, their most recently published RCT reports were retrieved and evaluated to assess whether the journals have followed what the CONSORT Statement required. Out of the 195 medical journals publishing clinical research papers, only six (6/195, 3.08% mentioned 'CONSORT' in their instructions for authors; out of the 200 medical journals surveyed, only 14 (14/200, 7.00% mentioned 'ICMJE' or 'URM' in their instructions for authors, and another five journals stated in their instructions for authors that clinical trials should have trial registration numbers and that priority would be given to clinical trials which had been registered. Among the 62 RCT reports published in the six journals endorsing the CONSORT Statement, 20 (20/62, 32.26% contained flow diagrams and only three (3/62, 4.84% provided trial registration information. CONCLUSIONS/SIGNIFICANCE: Medical journals in China endorsing either the CONSORT Statement or the

SU-F-J-98: Improvement and Evaluation Of Deformation Image Registration On Parotid Glands During Radiation Therapy for Nasopharyngeal Cancer

Energy Technology Data Exchange (ETDEWEB)

Xu, S [Tsinghua University, Beijing (China); PLA General Hospital, Beijing (China); Wu, Z; Liu, Y [Tsinghua University, Beijing (China); Liu, B; Li, Y; Zhou, F [Beihang University, Beijing (China); Gong, H; Qu, B [PLA General Hospital, Beijing (China)

2016-06-15

Purpose: To quantitatively evaluate the strategic innovation and accuracy variation of deformation registration algorithm for parotid glands using the similarity Dice coefficient during the course of radiation therapy (RT) for nasopharyngeal cancer (NPC). Methods: Daily MVCT data for 10 patients with pathologically proven nasopharyngeal cancers were analyzed. The data were acquired using tomotherapy (TomoTherapy, Accuray) at the PLA General Hospital. The prescription dose to the primary target was 70Gy in 33 fractions. Two kinds of contours for parotid glands on daily MVCTs were obtained by populating these contours from planning CTs to the daily CTs via rigid-body registration with or without the rotation shifts using the in-house tools and the Adaptive plan software (Adaptive Plan, TomoTherapy), and were edited manually if necessary. The diffeomorphic Demons algorithm developed in the in-house tool was used to propagate the parotid structures from the daily CTs to planning CTs. The differences of the mapped parotid contours in two methods were evaluated using Dice similarity index (DSI). Two-tailed t-test analysis was carried out to compare the DSI changes during the course of RT. Results: For 10 patient plans, the accuracy of deformation image registration (DIR) with the rotation shift was obviously better than those without the rotation shift. The Dice scores of the ipsi- and contra-lateral parotids for with and without the rotation shifts were found to be correlated with each other [0.904±0.031 vs 0.919±0.030 (p<0.001); 0.900±0.031 vs 0.910±0.032 (p<0.001)]. The Dice scores for the parotids have shown the reduction with the changes of parotid volumes during RT. The DSI values between the first and last fraction were 0.932±0.020 vs 0.899±0.030 in 10 patient plans. Conclusion: DIR was successfully improved using the strategic innovation for ART. And the decrease of DIR accuracy has also been found during the delivery of fractionated radiotherapy. This work

High performance deformable image registration algorithms for manycore processors

CERN Document Server

Shackleford, James; Sharp, Gregory

2013-01-01

High Performance Deformable Image Registration Algorithms for Manycore Processors develops highly data-parallel image registration algorithms suitable for use on modern multi-core architectures, including graphics processing units (GPUs). Focusing on deformable registration, we show how to develop data-parallel versions of the registration algorithm suitable for execution on the GPU. Image registration is the process of aligning two or more images into a common coordinate frame and is a fundamental step to be able to compare or fuse data obtained from different sensor measurements. E

Visitor Registration System

Data.gov (United States)

US Agency for International Development — Visitor Registration System (VRS) streamlines visitor check-in and check-out process for expediting visitors into USAID. The system captures visitor information...

Investigation of six-degree-of-freedom image registration between planning and cone beam computed tomography in esophageal cancer

International Nuclear Information System (INIS)

Li Jiancheng; Pan Jianji; Hu Cairong; Wang Xiaoliang; Cheng Wenfang; Zhao Yunhui

2010-01-01

Objective: To explore six-degree-of-freedom (6-DF) registration methods between planning and cone beam computed tomography (CBCT) during image-guided radiation therapy (IGRT) in esophageal cancer. Methods: Thirty pairs of CBCT images acquired before radiation and the corresponding planning computed tomography (CT) images of esophageal cancer were selected for further investigation. Registration markers for 6-DF image registration were determined and contoured in those images. The results of registration as well as time cost were compared among different registration methods of bone match, gray value match, manual match, and bone plus manual match. Results: Contouring bone and spinal canal posterior to the target volume of esophageal carcinoma as registration marker could make 6-DF registration quick and precise. Compared with manual match, set-up errors of v rotation in bone plus manual match (-0.55 degree vs.-0.88 degree, t=2.55, P=0.020), of x-axis and v rotation in bone match (0.12 mm vs.-2.33 mm, t=5.75, P=0.000; -0.35 degree vs. -0.88 degree, t=3.00, P=0.007), and of x-axis and w rotation in gray value match (7.20 mm vs. -2.33 mm, t=3.10, P=0.006; -0.10 degree vs. -0.59 degree, t=2.81, P =0.011) were significantly different. Compared with manual match, the coincidence rate of bone plus manual match was the highest (85.55%), followed by bone match and gray value match (74.45% and 74.45%). The time cost of each registration method from longest to shortest was: 6.00 -10.00 minutes for manual match, 1.00 - 5.00 minutes for bone plus manual match, 0.75 - 1.50 minutes for gray value match, and 0.50 - 0.83 minutes for bone match. Conclusions: Registration marker is useful for image registration of CBCT and planning CT in patients with esophageal cancer. Bone plus manual match may be the best registration method considering both registration time and accuracy. (authors)

Development of a QA Phantom for online image registration and resultant couch shifts

International Nuclear Information System (INIS)

Arumugam, S.; Jameson, M.G.; Holloway, L.C.

2010-01-01

Full text: Purpose Recently our centre purchased an Elekta-Synergy accelerator with kV-CBCT and a hexapod couch attachment. This system allows six degrees of freedom for couch lOp shifts, based on registration of on line imaging. We designed and built a phantom in our centre to test the accuracy and precision of this system. The goal of this project was to investigate the accuracy and practical utilisation of this phantom. Method The phantom was constructed from perspex sheets and high density dental putty (Fig. I). Five high density regions (three small regions to simulate prostate seeds and two larger regions to simulate boney anatomy) were incorporated to test the manual and automatic registrations within the software. The phantom was utilised to test the accuracy and precision of repositioning with the hexapod couch and imaging system. To achieve this, the phantom was placed on the couch at known orientations and the shifts were quantified using the registration of verification and reference image data sets. True shifts and those predicted by the software were compared. Results The geometrical accuracy of the phantom was verified with measurements of the CT scan to be with I mm of the intended geometry. The image registration and resultant couch shifts were found to be accurate within I mm and 0.5 degrees. The phantom was found to be practical and easy to use. Conclusion The presented phantom provides a less expensive and effective alternative to commercially available systems for verifying imaging registration and corresponding six degrees of freedom couch shifts. (author)

12 CFR 998.2 - Registration and periodic disclosures.

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2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Registration and periodic disclosures. 998.2 Section 998.2 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK DISCLOSURES REGISTRATION OF FEDERAL HOME LOAN BANK EQUITY SECURITIES § 998.2 Registration and periodic disclosures. (a...

17 CFR 31.6 - Registration of leverage commodities.

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2010-04-01

... taking delivery to buy or sell the leverage commodity; (2) Explain the effect of such changes upon the... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Registration of leverage... LEVERAGE TRANSACTIONS § 31.6 Registration of leverage commodities. (a) Registration of leverage commodities...

Remote Sensing Image Registration Using Multiple Image Features

Directory of Open Access Journals (Sweden)

Kun Yang

2017-06-01

Full Text Available Remote sensing image registration plays an important role in military and civilian fields, such as natural disaster damage assessment, military damage assessment and ground targets identification, etc. However, due to the ground relief variations and imaging viewpoint changes, non-rigid geometric distortion occurs between remote sensing images with different viewpoint, which further increases the difficulty of remote sensing image registration. To address the problem, we propose a multi-viewpoint remote sensing image registration method which contains the following contributions. (i A multiple features based finite mixture model is constructed for dealing with different types of image features. (ii Three features are combined and substituted into the mixture model to form a feature complementation, i.e., the Euclidean distance and shape context are used to measure the similarity of geometric structure, and the SIFT (scale-invariant feature transform distance which is endowed with the intensity information is used to measure the scale space extrema. (iii To prevent the ill-posed problem, a geometric constraint term is introduced into the L2E-based energy function for better behaving the non-rigid transformation. We evaluated the performances of the proposed method by three series of remote sensing images obtained from the unmanned aerial vehicle (UAV and Google Earth, and compared with five state-of-the-art methods where our method shows the best alignments in most cases.

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

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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.

40 CFR 152.99 - Petitions to cancel registration.

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2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Petitions to cancel registration. 152... Submitters' Rights § 152.99 Petitions to cancel registration. An original data submitter may petition the Agency to deny or cancel the registration of a product in accordance with this section if he has...

49 CFR 107.503 - Registration statement.

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2010-10-01

... tank motor vehicles which the registrant intends to manufacture, assemble, repair, inspect, test or... this section, each person who repairs a cargo tank or cargo tank motor vehicle must submit a copy of... PROGRAM PROCEDURES Registration of Cargo Tank and Cargo Tank Motor Vehicle Manufacturers, Assemblers...

76 FR 57045 - Announcement of Requirements and Registration for “Reporting Device Adverse Events Challenge”

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2011-09-15

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Announcement of Requirements and Registration for ``Reporting Device Adverse Events Challenge'' Authority: 15 U.S.C. 3719. AGENCY: Office of the National..., specifically as it relates to monitoring product safety and effectiveness. The ``Reporting Device Adverse...

Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation

International Nuclear Information System (INIS)

Chono, Taiki; Shimoshige, Shinya; Yoshikawa, Kenta; Mizonobe, Kazuhusa; Ogura, Keishi

2013-01-01

In CARTOMERGE for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time. (author)

2D/3D registration using a rotation-invariant cost function based on Zernike moments

Science.gov (United States)

Birkfellner, Wolfgang; Yang, Xinhui; Burgstaller, Wolfgang; Baumann, Bernard; Jacob, Augustinus L.; Niederer, Peter F.; Regazzoni, Pietro; Messmer, Peter

2004-05-01

We present a novel in-plane rotation invariant cost function for 2D/3D registration utilizing projection-invariant transformation properties and the decomposition of the X-ray nad the DRR under comparision into orhogonal Zernike moments. As a result, only five dof have to be optimized, and the number of iteration necessary for registration can be significantly reduced. Results in a phantom study show that an accuracy of approximately 0.7° and 2 mm can be achieved using this method. We conclude that reduction of coupled dof and usage of linear independent coefficients for cost function evaluation provide intersting new perspectives for the field of 2D/3D registration.

Registration of synthetic tomographic projection data sets using cross-correlation

International Nuclear Information System (INIS)

Fitchard, E.E.; Aldridge, J.S.; Reckwerdt, P.J.; Mackie, T.R.

1998-01-01

Tomographic registration, a method that makes possible accurate patient registration directly from projection data, consists of three processing steps: (i) manual coarse positioning, (ii) tomographic projection set acquisition, and (iii) computer mediated refined positioning. In the coarse positioning stage, the degree of patient alignment is comparable with that achieved with the standard radiotherapy set-up. However, the accuracy requirements are somewhat more relaxed in that meticulous alignment of the patient using external laser indicators is not necessary. Instead, tomographic projection sets are compared with planning CTs in order to achieve improved patient set-up. The projection sets are cross-correlated to obtain the best-fit translation and rotation offsets. The algorithm has been tested on synthetic data with the incorporation of varying amounts of Gaussian pseudo-random noise. These tests demonstrate the algorithm's stability and also confirm that alignment can be achieved with an accuracy of less than one projection pixel. (author)

Fast parallel image registration on CPU and GPU for diagnostic classification of Alzheimer's disease.

Science.gov (United States)

Shamonin, Denis P; Bron, Esther E; Lelieveldt, Boudewijn P F; Smits, Marion; Klein, Stefan; Staring, Marius

2013-01-01

Nonrigid image registration is an important, but time-consuming task in medical image analysis. In typical neuroimaging studies, multiple image registrations are performed, i.e., for atlas-based segmentation or template construction. Faster image registration routines would therefore be beneficial. In this paper we explore acceleration of the image registration package elastix by a combination of several techniques: (i) parallelization on the CPU, to speed up the cost function derivative calculation; (ii) parallelization on the GPU building on and extending the OpenCL framework from ITKv4, to speed up the Gaussian pyramid computation and the image resampling step; (iii) exploitation of certain properties of the B-spline transformation model; (iv) further software optimizations. The accelerated registration tool is employed in a study on diagnostic classification of Alzheimer's disease and cognitively normal controls based on T1-weighted MRI. We selected 299 participants from the publicly available Alzheimer's Disease Neuroimaging Initiative database. Classification is performed with a support vector machine based on gray matter volumes as a marker for atrophy. We evaluated two types of strategies (voxel-wise and region-wise) that heavily rely on nonrigid image registration. Parallelization and optimization resulted in an acceleration factor of 4-5x on an 8-core machine. Using OpenCL a speedup factor of 2 was realized for computation of the Gaussian pyramids, and 15-60 for the resampling step, for larger images. The voxel-wise and the region-wise classification methods had an area under the receiver operator characteristic curve of 88 and 90%, respectively, both for standard and accelerated registration. We conclude that the image registration package elastix was substantially accelerated, with nearly identical results to the non-optimized version. The new functionality will become available in the next release of elastix as open source under the BSD license.

Endorsement of the CONSORT guidelines, trial registration, and the quality of reporting randomised controlled trials in leading nursing journals: A cross-sectional analysis.

Science.gov (United States)

Jull, Andrew; Aye, Phyu Sin

2015-06-01

To establish the reporting quality of trials published in leading nursing journals and investigate associations between CONSORT Statement or trial registration endorsment and reporting of design elements. The top 15 nursing journals were searched using Medline for randomised controlled trials published in 2012. Journals were categorised as CONSORT and trial registration promoting based on requirements of submitting authors or the journal's webpage as at January 2014. Data on sequence generation, allocation concealment, follow up, blinding, baseline equivalence and sample size calculation were extracted by one author and independently verified by the second author against source data. Seven journals were CONSORT promoting and three of these journals were also trial registration promoting. 114 citations were identified and 83 were randomised controlled trials. Eighteen trials (21.7%) were registered and those published in trial registration promoting journals were more likely to be registered (RR 2.64 95%CI 1.14-6.09). We assessed 68.7% of trials to be low risk of bias for sequence generation, 20.5% for allocation concealment, 38.6% for blinding, 55.4% for completeness of follow up and 79.5% for baseline equivalence. Trials published in CONSORT promoting journals were more likely to be at low risk of bias for blinding (RR 2.33, 95%CI 1.01-5.34) and completeness of follow up (RR 1.77, 95%CI 1.02-3.10), but journal endorsement of the CONSORT Statement or trial registration otherwise had no significant effect. Trials published in CONSORT and trial registration promoting journals were more likely to have high quality sample size calculations (RR 2.91, 95%CI 1.18-7.19 and RR 1.69, 95%CI 1.08-2.64, respectively). Simple endorsement of the CONSORT Statement and trials registration is insufficient action to encourage improvement of the quality of trial reporting across the most important of trial design elements. Copyright © 2014 Elsevier Ltd. All rights reserved.

32 CFR 636.9 - Registration requirement.

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2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Registration requirement. 636.9 Section 636.9 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.9 Registration requirement. In...

Fast fluid registration of medical images

DEFF Research Database (Denmark)

Bro-Nielsen, Morten; Gramkow, Claus

1996-01-01

This paper offers a new fast algorithm for non-rigid viscous fluid registration of medical images that is at least an order of magnitude faster than the previous method by (Christensen et al., 1994). The core algorithm in the fluid registration method is based on a linear elastic deformation...

Workplace-based assessment for vocational registration of international medical graduates.

Science.gov (United States)

Lillis, Steven; Van Dyk, Valencia

2014-01-01

Medical regulatory authorities need efficient and effective methods of ensuring the competence of immigrating international medical graduates (IMGs). Not all IMGs who apply for specialist vocational registration will have directly comparable qualifications to those usually accepted. As general licensure examinations are inappropriate for these doctors, workplace-based assessment (WBA) techniques would appear to provide a solution. However, there is little published data on such outcomes. All cases of WBA (n = 81) used for vocational registration of IMGs in New Zealand between 2008 and 2013 were collated and analyzed. The successful completion rate of IMGs through the pathway was 87%. The majority (64%) undertook the year of supervised practice and the final assessment in a provincial center. For those unsuccessful in the pathway, inadequate clinical knowledge was the most common deficit found, followed by poor clinical reasoning. A WBA approach for assessing readiness of IMGs for vocational registration is feasible. The constructivist theoretical perspective of WBA has particular advantages in assessing the standard of practice for experienced practitioners working in narrow scopes than traditional methods of assessment. The majority of IMGs undertook both the clinical year and the assessment in provincial hospitals, thus providing a workforce for underserved areas. © 2014 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on Continuing Medical Education, Association for Hospital Medical Education.

Geometric registration of remotely sensed data with SAMIR

Science.gov (United States)

Gianinetto, Marco; Barazzetti, Luigi; Dini, Luigi; Fusiello, Andrea; Toldo, Roberto

2015-06-01

The commercial market offers several software packages for the registration of remotely sensed data through standard one-to-one image matching. Although very rapid and simple, this strategy does not take into consideration all the interconnections among the images of a multi-temporal data set. This paper presents a new scientific software, called Satellite Automatic Multi-Image Registration (SAMIR), able to extend the traditional registration approach towards multi-image global processing. Tests carried out with high-resolution optical (IKONOS) and high-resolution radar (COSMO-SkyMed) data showed that SAMIR can improve the registration phase with a more rigorous and robust workflow without initial approximations, user's interaction or limitation in spatial/spectral data size. The validation highlighted a sub-pixel accuracy in image co-registration for the considered imaging technologies, including optical and radar imagery.

Development of a registration framework to validate MRI with histology for prostate focal therapy.

Science.gov (United States)

Reynolds, H M; Williams, S; Zhang, A; Chakravorty, R; Rawlinson, D; Ong, C S; Esteva, M; Mitchell, C; Parameswaran, B; Finnegan, M; Liney, G; Haworth, A

2015-12-01

Focal therapy has been proposed as an alternative method to whole-gland treatment for prostate cancer when aiming to reduce treatment side effects. The authors recently validated a radiobiological model which takes into account tumor location and tumor characteristics including tumor cell density, Gleason score, and hypoxia in order to plan optimal dose distributions for focal therapy. The authors propose that this model can be informed using multiparametric MRI (mpMRI) and in this study present a registration framework developed to map prostate mpMRI and histology data, where histology will provide the "ground truth" data regarding tumor location and biology. The authors aim to apply this framework to a growing database to develop a prostate biological atlas which will enable MRI based planning for prostate focal therapy treatment. Six patients scheduled for routine radical prostatectomy were used in this proof-of-concept study. Each patient underwent mpMRI scanning prior to surgery, after which the excised prostate specimen was formalin fixed and mounted in agarose gel in a custom designed sectioning box. T2-weighted MRI of the specimen in the sectioning box was acquired, after which 5 mm sections of the prostate were cut and histology sections were microtomed. A number of image processing and registration steps were used to register histology images with ex vivo MRI and deformable image registration (DIR) was applied to 3D T2w images to align the in vivo and ex vivo MRI data. Dice coefficient metrics and corresponding feature points from two independent annotators were selected in order to assess the DIR accuracy. Images from all six patients were registered, providing histology and in vivo MRI in the ex vivo MRI frame of reference for each patient. Results demonstrated that their DIR methodology to register in vivo and ex vivo 3D T2w MRI improved accuracy in comparison with an initial manual alignment for prostates containing features which were readily visible

Registration in the Danish Regional Nonmelanoma Skin Cancer Dermatology Database: completeness of registration and accuracy of key variables

Directory of Open Access Journals (Sweden)

Anna L Lamberg

2010-05-01

Full Text Available Anna L Lamberg1, Deirdre Cronin-Fenton2, Anne B Olesen11Department of Dermatology, 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, C, DenmarkObjective: To validate a clinical database for nonmelanoma skin cancer (NMSC with the aim of monitoring and predicting the prognosis of NMSC treated by dermatologists in clinics in the central and north Denmark regions.Methods: We assessed the completeness of registration of patients and follow-up visits, and positive predictive value (PPV, negative predictive value (NPV, sensitivity, and specificity of registrations in the database. We used the Danish Pathology Registry (DPR (n = 288 and a review of randomly selected medical records (n = 67 from two clinics as gold standards.Results: The completeness of registration of patients was 62% and 76% with DPR and medical record review as gold standards, respectively. The completeness of registration of 1st and 2nd follow up visits was 85% and 69%, respectively. The PPV and NPV ranged from 85% to 99%, and the sensitivity and specificity from 67% to 100%.Conclusion: Overall, the accuracy of variables registered in the NMSC database was satisfactory but completeness of patient registration and follow-up visits were modest. The NMSC database is a potentially valuable tool for monitoring and facilitating improvement of NMSC treatment in dermatology clinics. However, there is still room for improvement of registration of both patients and their follow-up visits.Keywords: nonmelanoma skin cancer, validation, database, positive predictive value, completeness

Determination of optimal ultrasound planes for the initialisation of image registration during endoscopic ultrasound-guided procedures.

Science.gov (United States)

Bonmati, Ester; Hu, Yipeng; Gibson, Eli; Uribarri, Laura; Keane, Geri; Gurusami, Kurinchi; Davidson, Brian; Pereira, Stephen P; Clarkson, Matthew J; Barratt, Dean C

2018-06-01

Navigation of endoscopic ultrasound (EUS)-guided procedures of the upper gastrointestinal (GI) system can be technically challenging due to the small fields-of-view of ultrasound and optical devices, as well as the anatomical variability and limited number of orienting landmarks during navigation. Co-registration of an EUS device and a pre-procedure 3D image can enhance the ability to navigate. However, the fidelity of this contextual information depends on the accuracy of registration. The purpose of this study was to develop and test the feasibility of a simulation-based planning method for pre-selecting patient-specific EUS-visible anatomical landmark locations to maximise the accuracy and robustness of a feature-based multimodality registration method. A registration approach was adopted in which landmarks are registered to anatomical structures segmented from the pre-procedure volume. The predicted target registration errors (TREs) of EUS-CT registration were estimated using simulated visible anatomical landmarks and a Monte Carlo simulation of landmark localisation error. The optimal planes were selected based on the 90th percentile of TREs, which provide a robust and more accurate EUS-CT registration initialisation. The method was evaluated by comparing the accuracy and robustness of registrations initialised using optimised planes versus non-optimised planes using manually segmented CT images and simulated ([Formula: see text]) or retrospective clinical ([Formula: see text]) EUS landmarks. The results show a lower 90th percentile TRE when registration is initialised using the optimised planes compared with a non-optimised initialisation approach (p value [Formula: see text]). The proposed simulation-based method to find optimised EUS planes and landmarks for EUS-guided procedures may have the potential to improve registration accuracy. Further work will investigate applying the technique in a clinical setting.

Registration of central paths and colonic polyps between supine and prone scans in computed tomography colonography: Pilot study

International Nuclear Information System (INIS)

Li Ping; Napel, Sandy; Acar, Burak; Paik, David S.; Jeffrey, R. Brooke Jr.; Beaulieu, Christopher F.

2004-01-01

Computed tomography colonography (CTC) is a minimally invasive method that allows the evaluation of the colon wall from CT sections of the abdomen/pelvis. The primary goal of CTC is to detect colonic polyps, precursors to colorectal cancer. Because imperfect cleansing and distension can cause portions of the colon wall to be collapsed, covered with water, and/or covered with retained stool, patients are scanned in both prone and supine positions. We believe that both reading efficiency and computer aided detection (CAD) of CTC images can be improved by accurate registration of data from the supine and prone positions. We developed a two-stage approach that first registers the colonic central paths using a heuristic and automated algorithm and then matches polyps or polyp candidates (CAD hits) by a statistical approach. We evaluated the registration algorithm on 24 patient cases. After path registration, the mean misalignment distance between prone and supine identical anatomic landmarks was reduced from 47.08 to 12.66 mm, a 73% improvement. The polyp registration algorithm was specifically evaluated using eight patient cases for which radiologists identified polyps separately for both supine and prone data sets, and then manually registered corresponding pairs. The algorithm correctly matched 78% of these pairs without user input. The algorithm was also applied to the 30 highest-scoring CAD hits in the prone and supine scans and showed a success rate of 50% in automatically registering corresponding polyp pairs. Finally, we computed the average number of CAD hits that need to be manually compared in order to find the correct matches among the top 30 CAD hits. With polyp registration, the average number of comparisons was 1.78 per polyp, as opposed to 4.28 comparisons without polyp registration

27 CFR 25.112 - Dealer registration.

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2010-04-01

.... Every brewer who sells, or offers for sale, any alcohol product (distilled spirits, wines, or beer) fit... registration. Registration covers all sales from the same location, including sales of wine, spirits, or other... for making sales of wine or beer at the customer's place of business. Otherwise, a brewer who conducts...

Tenure Security Reformand Electronic Registration: Exploring ...

African Journals Online (AJOL)

This paper examines the potential significance of updating registration practices in resolving some of the issues about tenure security in a transformative context. It deals with the importance of good governance in the context of land administration and considers its impact on intended reforms. Land registration practice as an ...

19 CFR 360.102 - Online registration.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Online registration. 360.102 Section 360.102... ANALYSIS SYSTEM § 360.102 Online registration. (a) In general. (1) Any importer, importing company, customs.... boxes will not be accepted. A user identification number will be issued within two business days...

Deformable image registration for cone-beam CT guided transoral robotic base-of-tongue surgery

International Nuclear Information System (INIS)

Reaungamornrat, S; Liu, W P; Otake, Y; Uneri, A; Siewerdsen, J H; Taylor, R H; Wang, A S; Nithiananthan, S; Schafer, S; Tryggestad, E; Richmon, J; Sorger, J M

2013-01-01

Transoral robotic surgery (TORS) offers a minimally invasive approach to resection of base-of-tongue tumors. However, precise localization of the surgical target and adjacent critical structures can be challenged by the highly deformed intraoperative setup. We propose a deformable registration method using intraoperative cone-beam computed tomography (CBCT) to accurately align preoperative CT or MR images with the intraoperative scene. The registration method combines a Gaussian mixture (GM) model followed by a variation of the Demons algorithm. First, following segmentation of the volume of interest (i.e. volume of the tongue extending to the hyoid), a GM model is applied to surface point clouds for rigid initialization (GM rigid) followed by nonrigid deformation (GM nonrigid). Second, the registration is refined using the Demons algorithm applied to distance map transforms of the (GM-registered) preoperative image and intraoperative CBCT. Performance was evaluated in repeat cadaver studies (25 image pairs) in terms of target registration error (TRE), entropy correlation coefficient (ECC) and normalized pointwise mutual information (NPMI). Retraction of the tongue in the TORS operative setup induced gross deformation >30 mm. The mean TRE following the GM rigid, GM nonrigid and Demons steps was 4.6, 2.1 and 1.7 mm, respectively. The respective ECC was 0.57, 0.70 and 0.73, and NPMI was 0.46, 0.57 and 0.60. Registration accuracy was best across the superior aspect of the tongue and in proximity to the hyoid (by virtue of GM registration of surface points on these structures). The Demons step refined registration primarily in deeper portions of the tongue further from the surface and hyoid bone. Since the method does not use image intensities directly, it is suitable to multi-modality registration of preoperative CT or MR with intraoperative CBCT. Extending the 3D image registration to the fusion of image and planning data in stereo-endoscopic video is anticipated to

Survey of Non-Rigid Registration Tools in Medicine.

Science.gov (United States)

Keszei, András P; Berkels, Benjamin; Deserno, Thomas M

2017-02-01

We catalogue available software solutions for non-rigid image registration to support scientists in selecting suitable tools for specific medical registration purposes. Registration tools were identified using non-systematic search in Pubmed, Web of Science, IEEE Xplore® Digital Library, Google Scholar, and through references in identified sources (n = 22). Exclusions are due to unavailability or inappropriateness. The remaining (n = 18) tools were classified by (i) access and technology, (ii) interfaces and application, (iii) living community, (iv) supported file formats, and (v) types of registration methodologies emphasizing the similarity measures implemented. Out of the 18 tools, (i) 12 are open source, 8 are released under a permissive free license, which imposes the least restrictions on the use and further development of the tool, 8 provide graphical processing unit (GPU) support; (ii) 7 are built on software platforms, 5 were developed for brain image registration; (iii) 6 are under active development but only 3 have had their last update in 2015 or 2016; (iv) 16 support the Analyze format, while 7 file formats can be read with only one of the tools; and (v) 6 provide multiple registration methods and 6 provide landmark-based registration methods. Based on open source, licensing, GPU support, active community, several file formats, algorithms, and similarity measures, the tools Elastics and Plastimatch are chosen for the platform ITK and without platform requirements, respectively. Researchers in medical image analysis already have a large choice of registration tools freely available. However, the most recently published algorithms may not be included in the tools, yet.

Wavelet based free-form deformations for nonrigid registration

Science.gov (United States)

Sun, Wei; Niessen, Wiro J.; Klein, Stefan

2014-03-01

In nonrigid registration, deformations may take place on the coarse and fine scales. For the conventional B-splines based free-form deformation (FFD) registration, these coarse- and fine-scale deformations are all represented by basis functions of a single scale. Meanwhile, wavelets have been proposed as a signal representation suitable for multi-scale problems. Wavelet analysis leads to a unique decomposition of a signal into its coarse- and fine-scale components. Potentially, this could therefore be useful for image registration. In this work, we investigate whether a wavelet-based FFD model has advantages for nonrigid image registration. We use a B-splines based wavelet, as defined by Cai and Wang.1 This wavelet is expressed as a linear combination of B-spline basis functions. Derived from the original B-spline function, this wavelet is smooth, differentiable, and compactly supported. The basis functions of this wavelet are orthogonal across scales in Sobolev space. This wavelet was previously used for registration in computer vision, in 2D optical flow problems,2 but it was not compared with the conventional B-spline FFD in medical image registration problems. An advantage of choosing this B-splines based wavelet model is that the space of allowable deformation is exactly equivalent to that of the traditional B-spline. The wavelet transformation is essentially a (linear) reparameterization of the B-spline transformation model. Experiments on 10 CT lung and 18 T1-weighted MRI brain datasets show that wavelet based registration leads to smoother deformation fields than traditional B-splines based registration, while achieving better accuracy.

SU-C-17A-03: Evaluation of Deformable Image Registration Methods Between MRI and CT for Prostate Cancer Radiotherapy

International Nuclear Information System (INIS)

Wen, N; Glide-Hurst, C; Zhong, H; Chin, K; Kumarasiri, A; Liu, C; Liu, M; Siddiqui, S

2014-01-01

Purpose: We evaluated the performance of two commercially available and one open source B-Spline deformable image registration (DIR) algorithms between T2-weighted MRI and treatment planning CT using the DICE indices. Methods: CT simulation (CT-SIM) and MR simulation (MR-SIM) for four prostate cancer patients were conducted on the same day using the same setup and immobilization devices. CT images (120 kVp, 500 mAs, voxel size = 1.1x1.1x3.0 mm3) were acquired using an open-bore CT scanner. T2-weighted Turbo Spine Echo (T2W-TSE) images (TE/TR/α = 80/4560 ms/90°, voxel size = 0.7×0.7×2.5 mm3) were scanned on a 1.0T high field open MR-SIM. Prostates, seminal vesicles, rectum and bladders were delineated on both T2W-TSE and CT images by the attending physician. T2W-TSE images were registered to CT images using three DIR algorithms, SmartAdapt (Varian), Velocity AI (Velocity) and Elastix (Klein et al 2010) and contours were propagated. DIR results were evaluated quantitatively or qualitatively by image comparison and calculating organ DICE indices. Results: Significant differences in the contours of prostate and seminal vesicles were observed between MR and CT. On average, volume changes of the propagated contours were 5%, 2%, 160% and 8% for the prostate, seminal vesicles, bladder and rectum respectively. Corresponding mean DICE indices were 0.7, 0.5, 0.8, and 0.7. The intraclass correlation coefficient (ICC) was 0.9 among three algorithms for the Dice indices. Conclusion: Three DIR algorithms for CT/MR registration yielded similar results for organ propagation. Due to the different soft tissue contrasts between MRI and CT, organ delineation of prostate and SVs varied significantly, thus efforts to develop other DIR evaluation metrics are warranted. Conflict of interest: Submitting institution has research agreements with Varian Medical System and Philips Healthcare

SU-C-17A-03: Evaluation of Deformable Image Registration Methods Between MRI and CT for Prostate Cancer Radiotherapy

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Wen, N; Glide-Hurst, C; Zhong, H; Chin, K; Kumarasiri, A; Liu, C; Liu, M; Siddiqui, S [I Chetty, Henry Ford Health System, Detroit, MI (United States)

2014-06-15

Purpose: We evaluated the performance of two commercially available and one open source B-Spline deformable image registration (DIR) algorithms between T2-weighted MRI and treatment planning CT using the DICE indices. Methods: CT simulation (CT-SIM) and MR simulation (MR-SIM) for four prostate cancer patients were conducted on the same day using the same setup and immobilization devices. CT images (120 kVp, 500 mAs, voxel size = 1.1x1.1x3.0 mm3) were acquired using an open-bore CT scanner. T2-weighted Turbo Spine Echo (T2W-TSE) images (TE/TR/α = 80/4560 ms/90°, voxel size = 0.7×0.7×2.5 mm3) were scanned on a 1.0T high field open MR-SIM. Prostates, seminal vesicles, rectum and bladders were delineated on both T2W-TSE and CT images by the attending physician. T2W-TSE images were registered to CT images using three DIR algorithms, SmartAdapt (Varian), Velocity AI (Velocity) and Elastix (Klein et al 2010) and contours were propagated. DIR results were evaluated quantitatively or qualitatively by image comparison and calculating organ DICE indices. Results: Significant differences in the contours of prostate and seminal vesicles were observed between MR and CT. On average, volume changes of the propagated contours were 5%, 2%, 160% and 8% for the prostate, seminal vesicles, bladder and rectum respectively. Corresponding mean DICE indices were 0.7, 0.5, 0.8, and 0.7. The intraclass correlation coefficient (ICC) was 0.9 among three algorithms for the Dice indices. Conclusion: Three DIR algorithms for CT/MR registration yielded similar results for organ propagation. Due to the different soft tissue contrasts between MRI and CT, organ delineation of prostate and SVs varied significantly, thus efforts to develop other DIR evaluation metrics are warranted. Conflict of interest: Submitting institution has research agreements with Varian Medical System and Philips Healthcare.

Phantom study and accuracy evaluation of an image-to-world registration approach used with electro-magnetic tracking system for neurosurgery

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Li, Senhu; Sarment, David

2015-12-01

Minimally invasive neurosurgery needs intraoperative imaging updates and high efficient image guide system to facilitate the procedure. An automatic image guided system utilized with a compact and mobile intraoperative CT imager was introduced in this work. A tracking frame that can be easily attached onto the commercially available skull clamp was designed. With known geometry of fiducial and tracking sensor arranged on this rigid frame that was fabricated through high precision 3D printing, not only was an accurate, fully automatic registration method developed in a simple and less-costly approach, but also it helped in estimating the errors from fiducial localization in image space through image processing, and in patient space through the calibration of tracking frame. Our phantom study shows the fiducial registration error as 0.348+/-0.028mm, comparing the manual registration error as 1.976+/-0.778mm. The system in this study provided a robust and accurate image-to-patient registration without interruption of routine surgical workflow and any user interactions involved through the neurosurgery.

Registration of DRRs and portal images for verification of stereotactic body radiotherapy: a feasibility study in lung cancer treatment

International Nuclear Information System (INIS)

Kuenzler, Thomas; Grezdo, Jozef; Bogner, Joachim; Birkfellner, Wolfgang; Georg, Dietmar

2007-01-01

Image guidance has become a pre-requisite for hypofractionated radiotherapy where the applied dose per fraction is increased. Particularly in stereotactic body radiotherapy (SBRT) for lung tumours, one has to account for set-up errors and intrafraction tumour motion. In our feasibility study, we compared digitally reconstructed radiographs (DRRs) of lung lesions with MV portal images (PIs) to obtain the displacement of the tumour before irradiation. The verification of the tumour position was performed by rigid intensity based registration and three different merit functions such as the sum of squared pixel intensity differences, normalized cross correlation and normalized mutual information. The registration process then provided a translation vector that defines the displacement of the target in order to align the tumour with the isocentre. To evaluate the registration algorithms, 163 test images were created and subsequently, a lung phantom containing an 8 cm 3 tumour was built. In a further step, the registration process was applied on patient data, containing 38 tumours in 113 fractions. To potentially improve registration outcome, two filter types (histogram equalization and display equalization) were applied and their impact on the registration process was evaluated. Generated test images showed an increase in successful registrations when applying a histogram equalization filter whereas the lung phantom study proved the accuracy of the selected algorithms, i.e. deviations of the calculated translation vector for all test algorithms were below 1 mm. For clinical patient data, successful registrations occurred in about 59% of anterior-posterior (AP) and 46% of lateral projections, respectively. When patients with a clinical target volume smaller than 10 cm 3 were excluded, successful registrations go up to 90% in AP and 50% in lateral projection. In addition, a reliable identification of the tumour position was found to be difficult for clinical target

Registration of DRRs and portal images for verification of stereotactic body radiotherapy: a feasibility study in lung cancer treatment

Energy Technology Data Exchange (ETDEWEB)

Kuenzler, Thomas [Department of Radiotherapy and Radiobiology, Medical University Vienna, Vienna (Austria); Grezdo, Jozef [Department of Radiotherapy, St Elisabeth Institute of Oncology, Bratislava (Slovakia); Bogner, Joachim [Department of Radiotherapy and Radiobiology, Medical University Vienna, Vienna (Austria); Birkfellner, Wolfgang [Center for Biomedical Engineering and Physics, Medical University Vienna, Vienna (Austria); Georg, Dietmar [Department of Radiotherapy and Radiobiology, Medical University Vienna, Vienna (Austria)

2007-04-21

Image guidance has become a pre-requisite for hypofractionated radiotherapy where the applied dose per fraction is increased. Particularly in stereotactic body radiotherapy (SBRT) for lung tumours, one has to account for set-up errors and intrafraction tumour motion. In our feasibility study, we compared digitally reconstructed radiographs (DRRs) of lung lesions with MV portal images (PIs) to obtain the displacement of the tumour before irradiation. The verification of the tumour position was performed by rigid intensity based registration and three different merit functions such as the sum of squared pixel intensity differences, normalized cross correlation and normalized mutual information. The registration process then provided a translation vector that defines the displacement of the target in order to align the tumour with the isocentre. To evaluate the registration algorithms, 163 test images were created and subsequently, a lung phantom containing an 8 cm{sup 3} tumour was built. In a further step, the registration process was applied on patient data, containing 38 tumours in 113 fractions. To potentially improve registration outcome, two filter types (histogram equalization and display equalization) were applied and their impact on the registration process was evaluated. Generated test images showed an increase in successful registrations when applying a histogram equalization filter whereas the lung phantom study proved the accuracy of the selected algorithms, i.e. deviations of the calculated translation vector for all test algorithms were below 1 mm. For clinical patient data, successful registrations occurred in about 59% of anterior-posterior (AP) and 46% of lateral projections, respectively. When patients with a clinical target volume smaller than 10 cm{sup 3} were excluded, successful registrations go up to 90% in AP and 50% in lateral projection. In addition, a reliable identification of the tumour position was found to be difficult for clinical

Efficient Variational Approaches for Deformable Registration of Images

Directory of Open Access Journals (Sweden)

Mehmet Ali Akinlar

2012-01-01

Full Text Available Dirichlet, anisotropic, and Huber regularization terms are presented for efficient registration of deformable images. Image registration, an ill-posed optimization problem, is solved using a gradient-descent-based method and some fundamental theorems in calculus of variations. Euler-Lagrange equations with homogeneous Neumann boundary conditions are obtained. These equations are discretized by multigrid and finite difference numerical techniques. The method is applied to the registration of brain MR images of size 65×65. Computational results indicate that the presented method is quite fast and efficient in the registration of deformable medical images.

21 CFR 1309.45 - Extension of registration pending final order.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Extension of registration pending final order. 1309.45 Section 1309.45 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE... for Registration: Revocation Or Suspension of Registration § 1309.45 Extension of registration pending...

32 CFR 636.8 - Registration policy.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Registration policy. 636.8 Section 636.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.8 Registration policy. In addition to th...

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.

elastix: a toolbox for intensity-based medical image registration.

Science.gov (United States)

Klein, Stefan; Staring, Marius; Murphy, Keelin; Viergever, Max A; Pluim, Josien P W

2010-01-01

Medical image registration is an important task in medical image processing. It refers to the process of aligning data sets, possibly from different modalities (e.g., magnetic resonance and computed tomography), different time points (e.g., follow-up scans), and/or different subjects (in case of population studies). A large number of methods for image registration are described in the literature. Unfortunately, there is not one method that works for all applications. We have therefore developed elastix, a publicly available computer program for intensity-based medical image registration. The software consists of a collection of algorithms that are commonly used to solve medical image registration problems. The modular design of elastix allows the user to quickly configure, test, and compare different registration methods for a specific application. The command-line interface enables automated processing of large numbers of data sets, by means of scripting. The usage of elastix for comparing different registration methods is illustrated with three example experiments, in which individual components of the registration method are varied.

COMPARISON OF VOLUMETRIC REGISTRATION ALGORITHMS FOR TENSOR-BASED MORPHOMETRY.

Science.gov (United States)

Villalon, Julio; Joshi, Anand A; Toga, Arthur W; Thompson, Paul M

2011-01-01

Nonlinear registration of brain MRI scans is often used to quantify morphological differences associated with disease or genetic factors. Recently, surface-guided fully 3D volumetric registrations have been developed that combine intensity-guided volume registrations with cortical surface constraints. In this paper, we compare one such algorithm to two popular high-dimensional volumetric registration methods: large-deformation viscous fluid registration, formulated in a Riemannian framework, and the diffeomorphic "Demons" algorithm. We performed an objective morphometric comparison, by using a large MRI dataset from 340 young adult twin subjects to examine 3D patterns of correlations in anatomical volumes. Surface-constrained volume registration gave greater effect sizes for detecting morphometric associations near the cortex, while the other two approaches gave greater effects sizes subcortically. These findings suggest novel ways to combine the advantages of multiple methods in the future.

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.

Fast Parallel Image Registration on CPU and GPU for Diagnostic Classification of Alzheimer's Disease

Directory of Open Access Journals (Sweden)

Denis P Shamonin

2014-01-01

Full Text Available Nonrigid image registration is an important, but time-consuming taskin medical image analysis. In typical neuroimaging studies, multipleimage registrations are performed, i.e. for atlas-based segmentationor template construction. Faster image registration routines wouldtherefore be beneficial.In this paper we explore acceleration of the image registrationpackage elastix by a combination of several techniques: iparallelization on the CPU, to speed up the cost function derivativecalculation; ii parallelization on the GPU building on andextending the OpenCL framework from ITKv4, to speed up the Gaussianpyramid computation and the image resampling step; iii exploitationof certain properties of the B-spline transformation model; ivfurther software optimizations.The accelerated registration tool is employed in a study ondiagnostic classification of Alzheimer's disease and cognitivelynormal controls based on T1-weighted MRI. We selected 299participants from the publicly available Alzheimer's DiseaseNeuroimaging Initiative database. Classification is performed with asupport vector machine based on gray matter volumes as a marker foratrophy. We evaluated two types of strategies (voxel-wise andregion-wise that heavily rely on nonrigid image registration.Parallelization and optimization resulted in an acceleration factorof 4-5x on an 8-core machine. Using OpenCL a speedup factor of ~2was realized for computation of the Gaussian pyramids, and 15-60 forthe resampling step, for larger images. The voxel-wise and theregion-wise classification methods had an area under thereceiver operator characteristic curve of 88% and 90%,respectively, both for standard and accelerated registration.We conclude that the image registration package elastix wassubstantially accelerated, with nearly identical results to thenon-optimized version. The new functionality will become availablein the next release of elastix as open source under the BSD license.

A posteriori registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment.

Science.gov (United States)

Kreich, Eliane Maria; Chibinski, Ana Cláudia; Coelho, Ulisses; Wambier, Letícia Stadler; Zedebski, Rosário de Arruda Moura; de Moraes, Mari Eli Leonelli; de Moraes, Luiz Cesar

2016-03-01

This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment.

A posterior registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment

Energy Technology Data Exchange (ETDEWEB)

Kreich, Eliane Maria; Chibinski, Ana Claudia; Coelho, Ulisses; Wambier, Leticia Stadler; Zedebski, Rosaio De Arruda Moura [School of Dentistry, Ponta Grossa State University, Ponta Grossa, Parana (Brazil); De Moraes, Mari Eli Leonelli; De Moraes, Luiz Cesar [Dept. of Dental Radiology, School of Dentistry, State University of Sao Paulo, Sao Jose dos Campos, Sao Paulo (Brazil)

2016-03-15

This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment.

A posterior registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment

International Nuclear Information System (INIS)

Kreich, Eliane Maria; Chibinski, Ana Claudia; Coelho, Ulisses; Wambier, Leticia Stadler; Zedebski, Rosaio De Arruda Moura; De Moraes, Mari Eli Leonelli; De Moraes, Luiz Cesar

2016-01-01

This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment

A Comparative Evaluation of 3 Different Free-Form Deformable Image Registration and Contour Propagation Methods for Head and Neck MRI: The Case of Parotid Changes During Radiotherapy.

Science.gov (United States)

Broggi, Sara; Scalco, Elisa; Belli, Maria Luisa; Logghe, Gerlinde; Verellen, Dirk; Moriconi, Stefano; Chiara, Anna; Palmisano, Anna; Mellone, Renata; Fiorino, Claudio; Rizzo, Giovanna

2017-06-01

To validate and compare the deformable image registration and parotid contour propagation process for head and neck magnetic resonance imaging in patients treated with radiotherapy using 3 different approaches-the commercial MIM, the open-source Elastix software, and an optimized version of it. Twelve patients with head and neck cancer previously treated with radiotherapy were considered. Deformable image registration and parotid contour propagation were evaluated by considering the magnetic resonance images acquired before and after the end of the treatment. Deformable image registration, based on free-form deformation method, and contour propagation available on MIM were compared to Elastix. Two different contour propagation approaches were implemented for Elastix software, a conventional one (DIR_Trx) and an optimized homemade version, based on mesh deformation (DIR_Mesh). The accuracy of these 3 approaches was estimated by comparing propagated to manual contours in terms of average symmetric distance, maximum symmetric distance, Dice similarity coefficient, sensitivity, and inclusiveness. A good agreement was generally found between the manual contours and the propagated ones, without differences among the 3 methods; in few critical cases with complex deformations, DIR_Mesh proved to be more accurate, having the lowest values of average symmetric distance and maximum symmetric distance and the highest value of Dice similarity coefficient, although nonsignificant. The average propagation errors with respect to the reference contours are lower than the voxel diagonal (2 mm), and Dice similarity coefficient is around 0.8 for all 3 methods. The 3 free-form deformation approaches were not significantly different in terms of deformable image registration accuracy and can be safely adopted for the registration and parotid contour propagation during radiotherapy on magnetic resonance imaging. More optimized approaches (as DIR_Mesh) could be preferable for critical

Validation of nonrigid registration for multi-tracer PET-CT treatment planning in rectal cancer radiotherapy

Science.gov (United States)

Slagmolen, Pieter; Roels, Sarah; Loeckx, Dirk; Haustermans, Karin; Maes, Frederik

2009-02-01

The goal of radiotherapy is to deliver maximal dose to the tumor and minimal dose to the surrounding tissue. This requires accurate target definition. In sites were the tumor is difficult to see on the CT images, such as for rectal cancer, PET-CT imaging can be used to better define the target. If the information from multiple PETCT images with different tracers needs to be combined, a nonrigid registration is indispensable to compensate for rectal tissue deformations. Such registration is complicated by the presence of different volumes of bowel gas in the images to be registered. In this paper, we evaluate the performance of different nonrigid registration approaches by looking at the overlap of manually delineated rectum contours after registration. Using a B-spline transformation model, the results for two similarity measures, sum of squared differences and mutual information, either calculated over the entire image or on a region of interest are compared. Finally, we also assess the effect of the registration direction. We show that the combination of MI with a region of interest is best able to cope with residual rectal contrast and differences in bowel filling. We also show that for optimal performance the registration direction should be chosen depending on the difference in bowel filling in the images to be registered.

Socioeconomic determinants of accessibility to birth registration in Lao PDR.

Science.gov (United States)

Nomura, Marika; Xangsayarath, Phonepadith; Takahashi, Kenzo; Kamiya, Yusuke; Siengsounthone, Latsamy; Ogino, Hina; Kobayashi, Jun

2018-01-08

The global coverage rate of birth registration is only around 65% for the population of children under five although birth registration secures protection and access to health services that are fundamental rights for all babies. This study aimed to perform a basic analysis of the accessibility to birth registration to better understand how to improve the birth registration system in the Lao PDR. For the analysis of birth registration and related socioeconomic factors, 9576 mother-child pairs were chosen from the data set of The Lao Social Indicator Survey 2011-12. After bivariate analysis with statistical tests including the chi-square test were conducted, logistic regression was performed to determine the variables that statistically influence accessibility to birth registration. Ethno-geographic factors and place of delivery were observed to be the factors associated with birth registration in this analysis. Many mothers in the Lao PDR deliver in their local communities. Therefore, capacity development of various human resources, such as Skilled Birth Attendant, to support the local administrative procedure of birth registration in their communities could be one option to overcoming the bottlenecks in the birth registration process in the Lao PDR.

Depth-resolved registration of transesophageal echo to x-ray fluoroscopy using an inverse geometry fluoroscopy system

Energy Technology Data Exchange (ETDEWEB)

Hatt, Charles R. [Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Tomkowiak, Michael T.; Dunkerley, David A. P.; Slagowski, Jordan M. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Funk, Tobias [Triple Ring Technologies, Inc., Newark, California 94560 (United States); Raval, Amish N. [Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Speidel, Michael A., E-mail: speidel@wisc.edu [Departments of Medical Physics and Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

2015-12-15

Purpose: Image registration between standard x-ray fluoroscopy and transesophageal echocardiography (TEE) has recently been proposed. Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system designed for cardiac procedures. This study presents a method for 3D registration of SBDX and TEE images based on the tomosynthesis and 3D tracking capabilities of SBDX. Methods: The registration algorithm utilizes the stack of tomosynthetic planes produced by the SBDX system to estimate the physical 3D coordinates of salient key-points on the TEE probe. The key-points are used to arrive at an initial estimate of the probe pose, which is then refined using a 2D/3D registration method adapted for inverse geometry fluoroscopy. A phantom study was conducted to evaluate probe pose estimation accuracy relative to the ground truth, as defined by a set of coregistered fiducial markers. This experiment was conducted with varying probe poses and levels of signal difference-to-noise ratio (SDNR). Additional phantom and in vivo studies were performed to evaluate the correspondence of catheter tip positions in TEE and x-ray images following registration of the two modalities. Results: Target registration error (TRE) was used to characterize both pose estimation and registration accuracy. In the study of pose estimation accuracy, successful pose estimates (3D TRE < 5.0 mm) were obtained in 97% of cases when the SDNR was 5.9 or higher in seven out of eight poses. Under these conditions, 3D TRE was 2.32 ± 1.88 mm, and 2D (projection) TRE was 1.61 ± 1.36 mm. Probe localization error along the source-detector axis was 0.87 ± 1.31 mm. For the in vivo experiments, mean 3D TRE ranged from 2.6 to 4.6 mm and mean 2D TRE ranged from 1.1 to 1.6 mm. Anatomy extracted from the echo images appeared well aligned when projected onto the SBDX images. Conclusions: Full 6 DOF image registration between SBDX and TEE is feasible and accurate to within 5 mm. Future studies will focus on

Estimation of mouse organ locations through registration of a statistical mouse atlas with micro-CT images.

Science.gov (United States)

Wang, Hongkai; Stout, David B; Chatziioannou, Arion F

2012-01-01

Micro-CT is widely used in preclinical studies of small animals. Due to the low soft-tissue contrast in typical studies, segmentation of soft tissue organs from noncontrast enhanced micro-CT images is a challenging problem. Here, we propose an atlas-based approach for estimating the major organs in mouse micro-CT images. A statistical atlas of major trunk organs was constructed based on 45 training subjects. The statistical shape model technique was used to include inter-subject anatomical variations. The shape correlations between different organs were described using a conditional Gaussian model. For registration, first the high-contrast organs in micro-CT images were registered by fitting the statistical shape model, while the low-contrast organs were subsequently estimated from the high-contrast organs using the conditional Gaussian model. The registration accuracy was validated based on 23 noncontrast-enhanced and 45 contrast-enhanced micro-CT images. Three different accuracy metrics (Dice coefficient, organ volume recovery coefficient, and surface distance) were used for evaluation. The Dice coefficients vary from 0.45 ± 0.18 for the spleen to 0.90 ± 0.02 for the lungs, the volume recovery coefficients vary from 0.96 ± 0.10 for the liver to 1.30 ± 0.75 for the spleen, the surface distances vary from 0.18 ± 0.01 mm for the lungs to 0.72 ± 0.42 mm for the spleen. The registration accuracy of the statistical atlas was compared with two publicly available single-subject mouse atlases, i.e., the MOBY phantom and the DIGIMOUSE atlas, and the results proved that the statistical atlas is more accurate than the single atlases. To evaluate the influence of the training subject size, different numbers of training subjects were used for atlas construction and registration. The results showed an improvement of the registration accuracy when more training subjects were used for the atlas construction. The statistical atlas-based registration was also compared with

Depth-resolved registration of transesophageal echo to x-ray fluoroscopy using an inverse geometry fluoroscopy system

International Nuclear Information System (INIS)

Hatt, Charles R.; Tomkowiak, Michael T.; Dunkerley, David A. P.; Slagowski, Jordan M.; Funk, Tobias; Raval, Amish N.; Speidel, Michael A.

2015-01-01

Purpose: Image registration between standard x-ray fluoroscopy and transesophageal echocardiography (TEE) has recently been proposed. Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system designed for cardiac procedures. This study presents a method for 3D registration of SBDX and TEE images based on the tomosynthesis and 3D tracking capabilities of SBDX. Methods: The registration algorithm utilizes the stack of tomosynthetic planes produced by the SBDX system to estimate the physical 3D coordinates of salient key-points on the TEE probe. The key-points are used to arrive at an initial estimate of the probe pose, which is then refined using a 2D/3D registration method adapted for inverse geometry fluoroscopy. A phantom study was conducted to evaluate probe pose estimation accuracy relative to the ground truth, as defined by a set of coregistered fiducial markers. This experiment was conducted with varying probe poses and levels of signal difference-to-noise ratio (SDNR). Additional phantom and in vivo studies were performed to evaluate the correspondence of catheter tip positions in TEE and x-ray images following registration of the two modalities. Results: Target registration error (TRE) was used to characterize both pose estimation and registration accuracy. In the study of pose estimation accuracy, successful pose estimates (3D TRE < 5.0 mm) were obtained in 97% of cases when the SDNR was 5.9 or higher in seven out of eight poses. Under these conditions, 3D TRE was 2.32 ± 1.88 mm, and 2D (projection) TRE was 1.61 ± 1.36 mm. Probe localization error along the source-detector axis was 0.87 ± 1.31 mm. For the in vivo experiments, mean 3D TRE ranged from 2.6 to 4.6 mm and mean 2D TRE ranged from 1.1 to 1.6 mm. Anatomy extracted from the echo images appeared well aligned when projected onto the SBDX images. Conclusions: Full 6 DOF image registration between SBDX and TEE is feasible and accurate to within 5 mm. Future studies will focus on

Efficient point cloud data processing in shipbuilding: Reformative component extraction method and registration method

Directory of Open Access Journals (Sweden)

Jingyu Sun

2014-07-01

Full Text Available To survive in the current shipbuilding industry, it is of vital importance for shipyards to have the ship components’ accuracy evaluated efficiently during most of the manufacturing steps. Evaluating components’ accuracy by comparing each component’s point cloud data scanned by laser scanners and the ship’s design data formatted in CAD cannot be processed efficiently when (1 extract components from point cloud data include irregular obstacles endogenously, or when (2 registration of the two data sets have no clear direction setting. This paper presents reformative point cloud data processing methods to solve these problems. K-d tree construction of the point cloud data fastens a neighbor searching of each point. Region growing method performed on the neighbor points of the seed point extracts the continuous part of the component, while curved surface fitting and B-spline curved line fitting at the edge of the continuous part recognize the neighbor domains of the same component divided by obstacles’ shadows. The ICP (Iterative Closest Point algorithm conducts a registration of the two sets of data after the proper registration’s direction is decided by principal component analysis. By experiments conducted at the shipyard, 200 curved shell plates are extracted from the scanned point cloud data, and registrations are conducted between them and the designed CAD data using the proposed methods for an accuracy evaluation. Results show that the methods proposed in this paper support the accuracy evaluation targeted point cloud data processing efficiently in practice.

SU-E-J-42: Customized Deformable Image Registration Using Open-Source Software SlicerRT

Energy Technology Data Exchange (ETDEWEB)

Gaitan, J Cifuentes; Chin, L; Pignol, J [Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Kirby, N; Pouliot, J [UC San Francisco, San Francisco, CA (United States); Lasso, A; Pinter, C; Fichtinger, G [Queen' s University, Kingston, Ontario (Canada)

2014-06-01

Purpose: SlicerRT is a flexible platform that allows the user to incorporate the necessary images registration and processing tools to improve clinical workflow. This work validates the accuracy and the versatility of the deformable image registration algorithm of the free open-source software SlicerRT using a deformable physical pelvic phantom versus available commercial image fusion algorithms. Methods: Optical camera images of nonradiopaque markers implanted in an anatomical pelvic phantom were used to measure the ground-truth deformation and evaluate the theoretical deformations for several DIR algorithms. To perform the registration, full and empty bladder computed tomography (CT) images of the phantom were obtained and used as fixed and moving images, respectively. The DIR module, found in SlicerRT, used a B-spline deformable image registration with multiple optimization parameters that allowed customization of the registration including a regularization term that controlled the amount of local voxel displacement. The virtual deformation field at the center of the phantom was obtained and compared to the experimental ground-truth values. The parameters of SlicerRT were then varied to improve spatial accuracy. To quantify image similarity, the mean absolute difference (MAD) parameter using Hounsfield units was calculated. In addition, the Dice coefficient of the contoured rectum was evaluated to validate the strength of the algorithm to transfer anatomical contours. Results: Overall, SlicerRT achieved one of the lowest MAD values across the algorithm spectrum, but slightly smaller mean spatial errors in comparison to MIM software (MIM). On the other hand, SlicerRT created higher mean spatial errors than Velocity Medical Solutions (VEL), although obtaining an improvement on the DICE to 0.91. The large spatial errors were attributed to the poor contrast in the prostate bladder interface of the phantom. Conclusion: Based phantom validation, SlicerRT is capable of

Monte Carlo Registration and Its Application with Autonomous Robots

Directory of Open Access Journals (Sweden)

Christian Rink

2016-01-01

Full Text Available This work focuses on Monte Carlo registration methods and their application with autonomous robots. A streaming and an offline variant are developed, both based on a particle filter. The streaming registration is performed in real-time during data acquisition with a laser striper allowing for on-the-fly pose estimation. Thus, the acquired data can be instantly utilized, for example, for object modeling or robot manipulation, and the laser scan can be aborted after convergence. Curvature features are calculated online and the estimated poses are optimized in the particle weighting step. For sampling the pose particles, uniform, normal, and Bingham distributions are compared. The methods are evaluated with a high-precision laser striper attached to an industrial robot and with a noisy Time-of-Flight camera attached to service robots. The shown applications range from robot assisted teleoperation, over autonomous object modeling, to mobile robot localization.

Multi-modal image registration: matching MRI with histology

Science.gov (United States)

Alic, Lejla; Haeck, Joost C.; Klein, Stefan; Bol, Karin; van Tiel, Sandra T.; Wielopolski, Piotr A.; Bijster, Magda; Niessen, Wiro J.; Bernsen, Monique; Veenland, Jifke F.; de Jong, Marion

2010-03-01

Spatial correspondence between histology and multi sequence MRI can provide information about the capabilities of non-invasive imaging to characterize cancerous tissue. However, shrinkage and deformation occurring during the excision of the tumor and the histological processing complicate the co registration of MR images with histological sections. This work proposes a methodology to establish a detailed 3D relation between histology sections and in vivo MRI tumor data. The key features of the methodology are a very dense histological sampling (up to 100 histology slices per tumor), mutual information based non-rigid B-spline registration, the utilization of the whole 3D data sets, and the exploitation of an intermediate ex vivo MRI. In this proof of concept paper, the methodology was applied to one tumor. We found that, after registration, the visual alignment of tumor borders and internal structures was fairly accurate. Utilizing the intermediate ex vivo MRI, it was possible to account for changes caused by the excision of the tumor: we observed a tumor expansion of 20%. Also the effects of fixation, dehydration and histological sectioning could be determined: 26% shrinkage of the tumor was found. The annotation of viable tissue, performed in histology and transformed to the in vivo MRI, matched clearly with high intensity regions in MRI. With this methodology, histological annotation can be directly related to the corresponding in vivo MRI. This is a vital step for the evaluation of the feasibility of multi-spectral MRI to depict histological groundtruth.

[History of the evaluation of medicines aiming for marketing authorization].

Science.gov (United States)

Caulin, C

2008-01-01

The European Directive on Medicines Evaluation and Marketing Authorization were issued in 1975. For more than 30 years, Marketing Authorization criteria have been defined as pharmaceutical and biological quality, therapeutic efficacy, and safety. The application comes from the pharmaceutical company and must include the full data on drug development. French procedures have always included practical assessment of the drug by health practitioners: clinicians, pharmacists, biologists, and specialists in biostatistics.

Avoiding Stair-Step Artifacts in Image Registration for GOES-R Navigation and Registration Assessment

Science.gov (United States)

Grycewicz, Thomas J.; Tan, Bin; Isaacson, Peter J.; De Luccia, Frank J.; Dellomo, John

2016-01-01

In developing software for independent verification and validation (IVV) of the Image Navigation and Registration (INR) capability for the Geostationary Operational Environmental Satellite R Series (GOES-R) Advanced Baseline Imager (ABI), we have encountered an image registration artifact which limits the accuracy of image offset estimation at the subpixel scale using image correlation. Where the two images to be registered have the same pixel size, subpixel image registration preferentially selects registration values where the image pixel boundaries are close to lined up. Because of the shape of a curve plotting input displacement to estimated offset, we call this a stair-step artifact. When one image is at a higher resolution than the other, the stair-step artifact is minimized by correlating at the higher resolution. For validating ABI image navigation, GOES-R images are correlated with Landsat-based ground truth maps. To create the ground truth map, the Landsat image is first transformed to the perspective seen from the GOES-R satellite, and then is scaled to an appropriate pixel size. Minimizing processing time motivates choosing the map pixels to be the same size as the GOES-R pixels. At this pixel size image processing of the shift estimate is efficient, but the stair-step artifact is present. If the map pixel is very small, stair-step is not a problem, but image correlation is computation-intensive. This paper describes simulation-based selection of the scale for truth maps for registering GOES-R ABI images.

Size variation and collapse of emphysema holes at inspiration and expiration CT scan: evaluation with modified length scale method and image co-registration

Directory of Open Access Journals (Sweden)

Oh SY

2017-07-01

Full Text Available Sang Young Oh,1,* Minho Lee,1,* Joon Beom Seo,1,* Namkug Kim,1,2,* Sang Min Lee,1 Jae Seung Lee,3 Yeon Mok Oh3 1Department of Radiology, 2Department of Convergence Medicine, 3Department of Pulmonology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: A novel approach of size-based emphysema clustering has been developed, and the size variation and collapse of holes in emphysema clusters are evaluated at inspiratory and expiratory computed tomography (CT. Thirty patients were visually evaluated for the size-based emphysema clustering technique and a total of 72 patients were evaluated for analyzing collapse of the emphysema hole in this study. A new approach for the size differentiation of emphysema holes was developed using the length scale, Gaussian low-pass filtering, and iteration approach. Then, the volumetric CT results of the emphysema patients were analyzed using the new method, and deformable registration was carried out between inspiratory and expiratory CT. Blind visual evaluations of EI by two readers had significant correlations with the classification using the size-based emphysema clustering method (r-values of reader 1: 0.186, 0.890, 0.915, and 0.941; reader 2: 0.540, 0.667, 0.919, and 0.942. The results of collapse of emphysema holes using deformable registration were compared with the pulmonary function test (PFT parameters using the Pearson’s correlation test. The mean extents of low-attenuation area (LAA, E1 (<1.5 mm, E2 (<7 mm, E3 (<15 mm, and E4 (≥15 mm were 25.9%, 3.0%, 11.4%, 7.6%, and 3.9%, respectively, at the inspiratory CT, and 15.3%, 1.4%, 6.9%, 4.3%, and 2.6%, respectively at the expiratory CT. The extents of LAA, E2, E3, and E4 were found to be significantly correlated with the PFT ­parameters (r=−0.53, −0.43, −0.48, and −0.25, with forced expiratory volume in 1 second (FEV1; −0.81, −0.62, −0.75, and

Intensity-based hierarchical elastic registration using approximating splines.

Science.gov (United States)

Serifovic-Trbalic, Amira; Demirovic, Damir; Cattin, Philippe C

2014-01-01

We introduce a new hierarchical approach for elastic medical image registration using approximating splines. In order to obtain the dense deformation field, we employ Gaussian elastic body splines (GEBS) that incorporate anisotropic landmark errors and rotation information. Since the GEBS approach is based on a physical model in form of analytical solutions of the Navier equation, it can very well cope with the local as well as global deformations present in the images by varying the standard deviation of the Gaussian forces. The proposed GEBS approximating model is integrated into the elastic hierarchical image registration framework, which decomposes a nonrigid registration problem into numerous local rigid transformations. The approximating GEBS registration scheme incorporates anisotropic landmark errors as well as rotation information. The anisotropic landmark localization uncertainties can be estimated directly from the image data, and in this case, they represent the minimal stochastic localization error, i.e., the Cramér-Rao bound. The rotation information of each landmark obtained from the hierarchical procedure is transposed in an additional angular landmark, doubling the number of landmarks in the GEBS model. The modified hierarchical registration using the approximating GEBS model is applied to register 161 image pairs from a digital mammogram database. The obtained results are very encouraging, and the proposed approach significantly improved all registrations comparing the mean-square error in relation to approximating TPS with the rotation information. On artificially deformed breast images, the newly proposed method performed better than the state-of-the-art registration algorithm introduced by Rueckert et al. (IEEE Trans Med Imaging 18:712-721, 1999). The average error per breast tissue pixel was less than 2.23 pixels compared to 2.46 pixels for Rueckert's method. The proposed hierarchical elastic image registration approach incorporates the GEBS

Evaluation of optimization methods for nonrigid medical image registration using mutual information and B-splines

NARCIS (Netherlands)

Klein, S.; Staring, M.; Pluim, J.P.W.

2007-01-01

A popular technique for nonrigid registration of medical images is based on the maximization of their mutual information, in combination with a deformation field parameterized by cubic B-splines. The coordinate mapping that relates the two images is found using an iterative optimization procedure.

REGISTRATION OF OVERLAPPING 3D POINT CLO UDS USING EXTRACTED LINE SEGMENTS

Directory of Open Access Journals (Sweden)

Poręba Martyna

2014-12-01

Full Text Available The registration of 3D point clouds collected from different scanner positions is necessary in order to avoid occlusions, ensure a full coverage of areas, and collect useful data for analyzing an d documenting the surrounding environment. This procedure involves three main stages: 1 choosing appropriate features, which can be reliably extracted; 2 matching conjugate primitives; 3 estimating the transformation parameters. Currently, points and spheres are most frequently chosen as the registration features. However, due to limited point cloud resolution, proper identification and precise measurement of a common point within the overlapping laser data is almost impossible. One possible solution to this problem may be a registration process based on the Iterative Closest Point (ICP algorithm or its variation. Alternatively, planar and linear feature - based registration techniques can also be applied. In this paper, we propose the use of line segments obtained from intersecting planes modelled within individual scans. Such primitives can be easily extracted even from low - density point clouds. Working with synthetic data, several existing line - based registration methods are evaluated according to their robustness to noise and the precision of the estimated transformation parameters. For the purpose of quantitative assessment, an accuracy criterion based on a modified Hausdorff distance is defined. Since a n automated matching of segments is a challenging task that influences the correctness of the transformation parameters, a correspondence - finding algorithm is developed. The tests show that our matching algorithm provides a correct pairing with an accuracy of 99 % at least, and about 8% of omitted line pairs.

Ex-Post Analysis of Land Title Registration in Ghana Since 2008 Merger

Directory of Open Access Journals (Sweden)

Richmond J. Ehwi

2016-04-01

Full Text Available Land ownership and security of title have continued to dominate land management discourses in many developing economies, leading to a proliferation of studies that explore, among other things, the nexus between land title registration and land security, women’s access to land, innovation in agriculture, access to finance, and economic development. For many years, Ghana experienced minimal success in formalizing land ownership and title registration. However, public confidence and expectations were raised once more in 2008 with the merger of four disparate land agencies into the New Lands Commission (NLC under the overarching ambit of the Land Administration Project (LAP. This article contributes to existing studies by evaluating the impact of the 2008 merger. This is accomplished by matching the project’s stated objectives with actual outcomes and situating the findings in the broader theoretical debate about land title registration and economic development. Using data gathered through interviews with officials of the Greater Accra Lands Commission and with prospective land title holders, the study concludes that there have not been any great gains in achieving the complete digitization of the title registration process and follow-up procedures. However, there has been a reduction in the turn-around time for processing land documents, from more than 36 months to about 3 months, as well as increased public awareness about the process of title registration. The study recommends further training of staff members of the NLC in handling the digitization process, institutionalization of anti-corruption and anti-bribery practices, and the introduction of a well-functioning customer feedback system.

The influence of the image registration method on the adaptive radiotherapy. A proof of the principle in a selected case of prostate IMRT.

Science.gov (United States)

Berenguer, Roberto; de la Vara, Victoria; Lopez-Honrubia, Veronica; Nuñez, Ana Teresa; Rivera, Miguel; Villas, Maria Victoria; Sabater, Sebastia

2018-01-01

To analyse the influence of the image registration method on the adaptive radiotherapy of an IMRT prostate treatment, and to compare the dose accumulation according to 3 different image registration methods with the planned dose. The IMRT prostate patient was CT imaged 3 times throughout his treatment. The prostate, PTV, rectum and bladder were segmented on each CT. A Rigid, a deformable (DIR) B-spline and a DIR with landmarks registration algorithms were employed. The difference between the accumulated doses and planned doses were evaluated by the gamma index. The Dice coefficient and Hausdorff distance was used to evaluate the overlap between volumes, to quantify the quality of the registration. When comparing adaptive vs no adaptive RT, the gamma index calculation showed large differences depending on the image registration method (as much as 87.6% in the case of DIR B-spline). The quality of the registration was evaluated using an index such as the Dice coefficient. This showed that the best result was obtained with DIR with landmarks compared with the rest and it was always above 0.77, reported as a recommended minimum value for prostate studies in a multi-centre review. Apart from showing the importance of the application of an adaptive RT protocol in a particular treatment, this work shows that the election of the registration method is decisive in the result of the adaptive radiotherapy and dose accumulation. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

A spline-based non-linear diffeomorphism for multimodal prostate registration.

Science.gov (United States)

Mitra, Jhimli; Kato, Zoltan; Martí, Robert; Oliver, Arnau; Lladó, Xavier; Sidibé, Désiré; Ghose, Soumya; Vilanova, Joan C; Comet, Josep; Meriaudeau, Fabrice

2012-08-01

This paper presents a novel method for non-rigid registration of transrectal ultrasound and magnetic resonance prostate images based on a non-linear regularized framework of point correspondences obtained from a statistical measure of shape-contexts. The segmented prostate shapes are represented by shape-contexts and the Bhattacharyya distance between the shape representations is used to find the point correspondences between the 2D fixed and moving images. The registration method involves parametric estimation of the non-linear diffeomorphism between the multimodal images and has its basis in solving a set of non-linear equations of thin-plate splines. The solution is obtained as the least-squares solution of an over-determined system of non-linear equations constructed by integrating a set of non-linear functions over the fixed and moving images. However, this may not result in clinically acceptable transformations of the anatomical targets. Therefore, the regularized bending energy of the thin-plate splines along with the localization error of established correspondences should be included in the system of equations. The registration accuracies of the proposed method are evaluated in 20 pairs of prostate mid-gland ultrasound and magnetic resonance images. The results obtained in terms of Dice similarity coefficient show an average of 0.980±0.004, average 95% Hausdorff distance of 1.63±0.48 mm and mean target registration and target localization errors of 1.60±1.17 mm and 0.15±0.12 mm respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Deformable image registration using convolutional neural networks

NARCIS (Netherlands)

Eppenhof, Koen A.J.; Lafarge, Maxime W.; Moeskops, Pim; Veta, Mitko; Pluim, Josien P.W.

2018-01-01

Deformable image registration can be time-consuming and often needs extensive parameterization to perform well on a specific application. We present a step towards a registration framework based on a three-dimensional convolutional neural network. The network directly learns transformations between

78 FR 59685 - Registration Review; Draft Human Health and Ecological Risk Assessment; Notice of Availability

Science.gov (United States)

2013-09-27

... issues, the Agency seeks information on any groups or segments of the population who, as a result of... document, compared to the general population. II. Authority EPA is conducting its registration review of... on specific areas that will reduce the uncertainties associated with the characterization of risk to...

Registration-based segmentation with articulated model from multipostural magnetic resonance images for hand bone motion animation.

Science.gov (United States)

Chen, Hsin-Chen; Jou, I-Ming; Wang, Chien-Kuo; Su, Fong-Chin; Sun, Yung-Nien

2010-06-01

The quantitative measurements of hand bones, including volume, surface, orientation, and position are essential in investigating hand kinematics. Moreover, within the measurement stage, bone segmentation is the most important step due to its certain influences on measuring accuracy. Since hand bones are small and tubular in shape, magnetic resonance (MR) imaging is prone to artifacts such as nonuniform intensity and fuzzy boundaries. Thus, greater detail is required for improving segmentation accuracy. The authors then propose using a novel registration-based method on an articulated hand model to segment hand bones from multipostural MR images. The proposed method consists of the model construction and registration-based segmentation stages. Given a reference postural image, the first stage requires construction of a drivable reference model characterized by hand bone shapes, intensity patterns, and articulated joint mechanism. By applying the reference model to the second stage, the authors initially design a model-based registration pursuant to intensity distribution similarity, MR bone intensity properties, and constraints of model geometry to align the reference model to target bone regions of the given postural image. The authors then refine the resulting surface to improve the superimposition between the registered reference model and target bone boundaries. For each subject, given a reference postural image, the proposed method can automatically segment all hand bones from all other postural images. Compared to the ground truth from two experts, the resulting surface image had an average margin of error within 1 mm (mm) only. In addition, the proposed method showed good agreement on the overlap of bone segmentations by dice similarity coefficient and also demonstrated better segmentation results than conventional methods. The proposed registration-based segmentation method can successfully overcome drawbacks caused by inherent artifacts in MR images and

Automated registration of freehand B-mode ultrasound and magnetic resonance imaging of the carotid arteries based on geometric features

DEFF Research Database (Denmark)

Carvalho, Diego D. B.; Arias Lorza, Andres Mauricio; Niessen, Wiro J.

2017-01-01

and segmentations by minimizing a weighted sum of the Euclidean distance between centerlines and the dissimilarity between segmentations. The method was evaluated in 28 carotid arteries from eight patients and six healthy volunteers. First, the automated US lumen segmentation method was validated and optimized......-and-point-based method, a registration using only the centerlines and a registration using manual US lumen segmentations. Registration accuracy was measured in terms of the mean surface distance between manual US segmentations and the registered MRI segmentations. The average mean surface distance was 0.78 ± 0.34 mm...

Validation of the deformable image registration system elastix in the head and neck region

DEFF Research Database (Denmark)

Zukauskaite, R.; Brink, C.; Hansen, C. R.

2015-01-01

evaluates the accuracy of the open source deformable registration tool elastix when used for registration of different organ structures on planning CT and relapse CT scans of head and neck patients. Materials and Methods: Twenty patients treated with definitive IMRT for oral cavity, oropharynx...... cord, mandible, right/left parotid and submandibular glands, thyroid gland and vertebrae C3-5) on planning CT (pCT), relapse CT (rCT) and re-delineated again on the planning CT (reCT). The contouring on the relapse CT was mapped to the planning CT using elastix (http://elastix.isi.uu.nl/). Spatial...... delineation. Significant correlations within single organs were not found. Conclusions: Deformable registration of head and neck CT images using elastix resulted in a combined delineation and deformation uncertainty of approximately twice the uncertainty related to the manual delineation performed on one CT...

Measuring the impact of a public awareness campaign to increase Welfare Power of Attorney registrations in Scotland.

Science.gov (United States)

Levin, Kate A; Carson, Jill; Crighton, Emilia

2017-07-01

to measure the impact of the 'My Power of Attorney' media campaign on the number of new power of attorney (POA) registrations in Scotland. POA registrations in Scotland processed by the Office of the Public Guardian during January 2010 to June 2015. multilevel Poisson models for POA registrations nested by council and annual quarter were run using Markov chain Monte Carlo methods, adjusting for time, campaign (variable ranging between 0 and 5 dependent on intensity of campaign measured by the number of media platforms received) and offset term mid-year population estimate for those aged 25 years+/65 years+. POA registrations saw a reduction between 2010 and 2011 but overall, increased between 2010 and 2015. POA registrations rose by 33.3% in Glasgow City between 2013 and 2014, when the campaign began, while the rest of Scotland saw a rise of 17.3%. When the data were modelled, Relative Risk (RR) of a POA registration increased with increasing intensity of campaign, so that in an area in receipt of the full campaign was RR = 1.31 (1.28, 1.34) that of an area with no campaign. Between council variation persisted after adjustment for campaign (Variance = 0.041 (0.011)). during the period of the campaign, area-level increases in POA registrations were observed associated with the 'My Power of Attorney' timing and location, in an approximate dose-response relationship with campaign intensity, suggesting that this is likely to be due to the campaign that began in Glasgow City. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

3D/2D model-to-image registration by imitation learning for cardiac procedures.

Science.gov (United States)

Toth, Daniel; Miao, Shun; Kurzendorfer, Tanja; Rinaldi, Christopher A; Liao, Rui; Mansi, Tommaso; Rhode, Kawal; Mountney, Peter

2018-05-12

In cardiac interventions, such as cardiac resynchronization therapy (CRT), image guidance can be enhanced by involving preoperative models. Multimodality 3D/2D registration for image guidance, however, remains a significant research challenge for fundamentally different image data, i.e., MR to X-ray. Registration methods must account for differences in intensity, contrast levels, resolution, dimensionality, field of view. Furthermore, same anatomical structures may not be visible in both modalities. Current approaches have focused on developing modality-specific solutions for individual clinical use cases, by introducing constraints, or identifying cross-modality information manually. Machine learning approaches have the potential to create more general registration platforms. However, training image to image methods would require large multimodal datasets and ground truth for each target application. This paper proposes a model-to-image registration approach instead, because it is common in image-guided interventions to create anatomical models for diagnosis, planning or guidance prior to procedures. An imitation learning-based method, trained on 702 datasets, is used to register preoperative models to intraoperative X-ray images. Accuracy is demonstrated on cardiac models and artificial X-rays generated from CTs. The registration error was [Formula: see text] on 1000 test cases, superior to that of manual ([Formula: see text]) and gradient-based ([Formula: see text]) registration. High robustness is shown in 19 clinical CRT cases. Besides the proposed methods feasibility in a clinical environment, evaluation has shown good accuracy and high robustness indicating that it could be applied in image-guided interventions.

Segmentation and registration duality from echographic images by use of physiological and morphological knowledge

International Nuclear Information System (INIS)

Ionescu, G.

1998-01-01

Echographic imaging could potentially play a major role in the field of Computer Assisted Surgery (CAS). For doctors and surgeons to make full use of tool in planning and executing surgical operations, they also need user-friendly automatic software based on fast, precise and reliable algorithms. The main goal of this thesis is to take advantage of the segmentation/registration duality to extract the relevant information from echo graphical images. This information will allow the precise and automatic registration both of anatomical structures contained in the pre-operative model and of per-operative data contained in echographic images. The result of registration will be further to guide a computer-assisted tool. In the first part we propose different methods for filtering, segmentation and calibration of echographic images. The development of fast, precise and reliable algorithms is emphasized. The second part concerns the segmentation-registration duality and the corrections of elastic deformations of soft tissues. High-level segmentation algorithms for echographic images were developed. They are based on results of low -level segmentation, a priori anatomical knowledge as well as on information provided by the pre-operative model. The third part deals with detailed descriptions of applications and interpretation of results. The cases studied include: screwing inside the vertebral pedicles, ilio-sacral screwing, prostatic radiotherapy and puncture of pericardial effusion. Future developments for this approach are discussed. (author)

Which authority, whose land? Access to land in Paser, East Kalimantan

NARCIS (Netherlands)

Bakker, L.G.H.

2010-01-01

The key issue in this study is access to land registration, which is the official responsibility of the National Land Agency (Badan Pertanahan Nasional, hereafter NLA). Nonetheless other official institutions such as the Department of Forestry and regional governments have authority over issues

The role of image registration in brain mapping

Science.gov (United States)

Toga, A.W.; Thompson, P.M.

2008-01-01

Image registration is a key step in a great variety of biomedical imaging applications. It provides the ability to geometrically align one dataset with another, and is a prerequisite for all imaging applications that compare datasets across subjects, imaging modalities, or across time. Registration algorithms also enable the pooling and comparison of experimental findings across laboratories, the construction of population-based brain atlases, and the creation of systems to detect group patterns in structural and functional imaging data. We review the major types of registration approaches used in brain imaging today. We focus on their conceptual basis, the underlying mathematics, and their strengths and weaknesses in different contexts. We describe the major goals of registration, including data fusion, quantification of change, automated image segmentation and labeling, shape measurement, and pathology detection. We indicate that registration algorithms have great potential when used in conjunction with a digital brain atlas, which acts as a reference system in which brain images can be compared for statistical analysis. The resulting armory of registration approaches is fundamental to medical image analysis, and in a brain mapping context provides a means to elucidate clinical, demographic, or functional trends in the anatomy or physiology of the brain. PMID:19890483

Optimization of PET-MR Registrations for Nonhuman Primates Using Mutual Information Measures: A Multi-Transform Method (MTM)

Science.gov (United States)

Sandiego, Christine M.; Weinzimmer, David; Carson, Richard E.

2012-01-01

An important step in PET brain kinetic analysis is the registration of functional data to an anatomical MR image. Typically, PET-MR registrations in nonhuman primate neuroreceptor studies used PET images acquired early post-injection, (e.g., 0–10 min) to closely resemble the subject’s MR image. However, a substantial fraction of these registrations (~25%) fail due to the differences in kinetics and distribution for various radiotracer studies and conditions (e.g., blocking studies). The Multi-Transform Method (MTM) was developed to improve the success of registrations between PET and MR images. Two algorithms were evaluated, MTM-I and MTM-II. The approach involves creating multiple transformations by registering PET images of different time intervals, from a dynamic study, to a single reference (i.e., MR image) (MTM-I) or to multiple reference images (i.e., MR and PET images pre-registered to the MR) (MTM-II). Normalized mutual information was used to compute similarity between the transformed PET images and the reference image(s) to choose the optimal transformation. This final transformation is used to map the dynamic dataset into the animal’s anatomical MR space, required for kinetic analysis. The chosen transformed from MTM-I and MTM-II were evaluated using visual rating scores to assess the quality of spatial alignment between the resliced PET and reference. One hundred twenty PET datasets involving eleven different tracers from 3 different scanners were used to evaluate the MTM algorithms. Studies were performed with baboons and rhesus monkeys on the HR+, HRRT, and Focus-220. Successful transformations increased from 77.5%, 85.8%, to 96.7% using the 0–10 min method, MTM-I, and MTM-II, respectively, based on visual rating scores. The Multi-Transform Methods proved to be a robust technique for PET-MR registrations for a wide range of PET studies. PMID:22926293

Multimodality image registration with software: state-of-the-art

International Nuclear Information System (INIS)

Slomka, Piotr J.; Baum, Richard P.

2009-01-01

Multimodality image integration of functional and anatomical data can be performed by means of dedicated hybrid imaging systems or by software image co-registration techniques. Hybrid positron emission tomography (PET)/computed tomography (CT) systems have found wide acceptance in oncological imaging, while software registration techniques have a significant role in patient-specific, cost-effective, and radiation dose-effective application of integrated imaging. Software techniques allow accurate (2-3 mm) rigid image registration of brain PET with CT and MRI. Nonlinear techniques are used in whole-body image registration, and recent developments allow for significantly accelerated computing times. Nonlinear software registration of PET with CT or MRI is required for multimodality radiation planning. Difficulties remain in the validation of nonlinear registration of soft tissue organs. The utilization of software-based multimodality image integration in a clinical environment is sometimes hindered by the lack of appropriate picture archiving and communication systems (PACS) infrastructure needed to efficiently and automatically integrate all available images into one common database. In cardiology applications, multimodality PET/single photon emission computed tomography and coronary CT angiography imaging is typically not required unless the results of one of the tests are equivocal. Software image registration is likely to be used in a complementary fashion with hybrid PET/CT or PET/magnetic resonance imaging systems. Software registration of stand-alone scans ''paved the way'' for the clinical application of hybrid scanners, demonstrating practical benefits of image integration before the hybrid dual-modality devices were available. (orig.)

Integration of breathing in radiotherapy: contribution of the image deformable registration

International Nuclear Information System (INIS)

Boldea, Vlad

2006-01-01

As taking organ movements and deformations into account in radiotherapy for the treatment of lung cancer is a challenge as it allows the delivered dose to be increased while better sparing surrounding sane tissues, this research thesis addresses non-rigid (or deformable) registration iconic methods applied to thorax X ray computed tomography (X-ray CT) 3D acquisitions. The objective is to extract the information regarding lung and tumour movement and deformation. The author thus reports the development of deformable registration framework with several methods of regularisation of vector fields. Three main studies have been performed and are reported. In the first one, deformable registration allowed the breathe blockage reproducibility to be controlled. Experiments performed on ten patients showed that this blockage is efficient (displacement less than 5 mm), except for three of them with functional anomalies. In a second study, 4D X-ray CT acquisitions (3D X-ray CT images acquired at different moments of the normal breathing cycle) have been analysed to extract and follow thorax movements and deformations in order to take them into account in free breathing and to perform 4D dynamic dosimetric studies. A first 4D X-ray CT image model has been developed from 3D X-ray CT images acquired in breathe blockage at the end of expiration and at the end on inhalation [fr

Effectiveness of an Integrated Tertiary Software Mobile Information System for Student Registration and Admission at a University in Gauteng

Directory of Open Access Journals (Sweden)

Frans MASHABELA

2017-07-01

Full Text Available This study investigates whether the new online registration and admission system implemented at a Tertiary Institution in Gauteng, South Africa, was successful and effective. The Institution under study is the first in South Africa to implement this new online registration system from the 3rd of January 2013 using a system called the Integrated Tertiary Software (ITS Mobile information system. The information system enables students to apply online without physically visiting the institution and provides the status of their registration and admission applications via their smartphones. A total of one hundred 1st year students and ten personnel were sampled to respond to self-completed questionnaires. The efficiency of this new online system was evaluated using the Technology Acceptance Model (TAM, the Web of System Performance (WOSP model and the DeLone and McLean IS Success model as well as the indicators of system ineffectiveness and attributes on the basis of which an information system was evaluated. Key findings emerging from the data analysis and interpretation show that the new online system met the expectations of most staff and students with the exception of few staff members and students. The findings show that the investment made on the new online registration system is benefiting the University and students. The implementation of the new online registration and admission system was a success to a larger extent because the expectations of most users were met. The online system is effective as it was evaluated using the conventional measuring methods and resulted in positive outcomes.

An evaluation of author productivity in international radiography journals 2004–2011