A rapid method of evaluating fluoroscopic system performance

International Nuclear Information System (INIS)

Sprawls, P.

1989-01-01

This paper presents a study to develop a method for the rapid evaluation and documentation of fluoroscopic image quality. All objects contained within a conventional contrast-detail test phantom (Leeds TO-10) are displayed in an array format according to their contrast and size. A copy of the display is used as the data collection form and a permanent record of system performance. A fluoroscope is evaluated by viewing the test phantom and marking the visible objects on the display. A line drawn through the objects with minimum visibility in each size group forms a contrast-detail curve for the system. This is compared with a standard or reference line, which is in the display.Deviations in curve position are useful indicators of specific image quality problems, such as excessive noise or blurring. The use of a special object-visibility array format display makes it possible to collect data, analyze the results, and create a record of fluoroscopic performance in less than 2 minutes for each viewing mode

Fluoroscopic Imaging Systems. Chapter 8

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Jones, A. K. [University of Texas MD Anderson Cancer Center, Houston (United States)

2014-09-15

Fluoroscopy refers to the use of an X ray beam and a suitable image receptor for viewing images of processes or instruments in the body in real time. Fluoroscopic imaging trades the high signal to noise ratio (SNR) of radiography for high temporal resolution, as factors that maintain patient dose at an acceptable level must be used.

Objective masurement of image quality in fluoroscopic x-ray equipment FluoroQuality

CERN Document Server

Tapiovaara, M

2003-01-01

The report describes FluoroQuality, a computer program that is developed in STUK and used for measuring the image quality in medical fluoroscopic equipment. The method is based on the statistical decision theory (SDT) and the main measurement result is given in terms of the accumulation rate of the signal-to-noise ratio squared (SNR sup 2 sub r sub a sub t sub e). In addition to this quantity several other quantities are measured. These quantities include the SNR of single image frames, the spatio-temporal noise power spectrum and the temporal lag. The measurement method can be used, for example, for specifying the image quality in fluoroscopic images, for optimising the image quality and dose rate in fluoroscopy and for quality control of fluoroscopic equipment. The theory behind the measurement method is reviewed and the measurement of the various quantities is explained. An example of using the method for optimising a specified fluoroscopic procedure is given. The User's Manual of the program is included a...

Trial manufacture of round mask for TV fluoroscopic unit

International Nuclear Information System (INIS)

Matsuoka, Shoji; Matsumoto, Yukio

1977-01-01

Demands for revision of existing medical law were described together with an introduction of TV fluoroscopic unit. Round mask, which does not always press out the bottom face of used x-ray beam from the effective primary fluorescent face of photomultiplier inspite of shifting of a spot in time of TV fluoroscopy, was manufactured for trial, and it was furnished with already established fluoroscopic stand. It is used in daily examination without any trouble. Round mask was divided into two parts, and opened upward and downward quickly by lod motor in time of photographing. Multiple iris was operated in order to fit to film size, and round mask was closed at the same time of the finishment of photographing and fluoroscopy was performed again. Item 3 of Para 2 of Art 30 of the existing medical low states that it is good not to press out, the distance between x-ray focus and fluorescent screen, and used x-ray beam from fluorescent screen. However, a regulation, which states that x-ray beam should not be pressed out from effective primary fluorescent face in x-ray fluoroscopy using photomultiplier, must be added. Improvement of the existing unit is expected, and decrease of unnecessary exposure even in small amount is proposed. (Tsunoda, M.)

Clinical application of transnasal feeding tube placement under fluoroscopic guidance

International Nuclear Information System (INIS)

Ge Kunyuan; Ni Caifang; Liu Yizhi; Zhu Xiaoli; Zou Jianwei; Jin Yonghai; Chen Long; Sun Ge; Sun Lingfang; Zhang Dong

2008-01-01

Objective: To evaluate the feasibility and effectiveness of duodenal feeding tube placement under fluoroscopic guidance and its clinical application. Methods: The transnasal duodenal nutriment tubes placement under fluoroscopic guidance were performed in 59 patients from June 3th, 2003 to August 17th, 2007. The successful placement of the feeding tube was defined as that of the tube tip was fixed at or distal to the duodenojejunal junction. Results: 57 out of 59 patients were successfully managed by feeding tube placement, with primary successful rate of 96.6% (57/59). The remaining two failures were due to overdistention of the stomach and were further managed after gastrointestinal decompression thoroughly. The mean fluoroscopy time of the procedure was 17.8 minutes with no severe immediate or delayed complications. Conclusion: The transnasal duodenal nutrient feeding tube placement under fluoroscopic guidance is a safe,economic, and effective management for enteral nutrition, providing extensive clinical utilization. (authors)

Reducing radiation exposure in an electrophysiology lab with introduction of newer fluoroscopic technology

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Munish Sharma

2017-09-01

Full Text Available The use of fluoroscopic devices exposes patients and operators to harmful effects of ionizing radiation in an electrophysiology (EP lab. We sought to know if the newer fluoroscopic technology (Allura Clarity installed in a hybrid EP helps to reduce prescribed radiation dose. We performed radiation dose analysis of 90 patients who underwent various procedures in the EP lab at a community teaching hospital after the introduction of newer fluoroscopic technology in June of 2016.Watchman device insertion, radiofrequency ablation procedures, permanent pacemaker (PPM/implantable cardioverter defibrillator (ICD placement and battery changes were included in the study to compare radiation exposure during different procedures performed commonly in an EP lab. In all cases of watchman device placement, radiofrequency ablation procedures, PPM/ICD placement and battery changes, there was a statistically significant difference (<0.05 in radiation dose exposure. Significant reduction in radiation exposure during various procedures performed in an EP lab was achieved with aid of newer fluoroscopic technology and better image detection technology.

New Jersey's Thomas Edison and the fluoroscope.

Science.gov (United States)

Tselos, G D

1995-11-01

Thomas Edison played a major role in the development of early x-ray technology in 1896, notably increasing tube power and reliability and making the fluoroscope a practical instrument. Eventually, Edison would move x-ray technology from the laboratory to the marketplace.

Radiation exposure from shoe-fitting fluoroscopes

International Nuclear Information System (INIS)

Busch, Uwe

2015-01-01

It is 40 years ago that a very popular X-ray device disappeared in German shoe shops: the shoe-fitting fluoroscope or Pedoskop. Since the 1930s, these X-ray machines were an integral part of any good shoe business. Following the entry into force X-Ray Regulation (RoeV 1973) the use of these devices was prohibited in Germany.

Technique of Peritoneal Catheter Placement under Fluoroscopic Guidance

International Nuclear Information System (INIS)

Abdel-Aal, A.K.; Gaddikeri, S.; Saddekni, S.

2011-01-01

Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

Fluoroscopically guided fallopian tube recanalization with a simplified set of instruments

International Nuclear Information System (INIS)

Schmitz-Rode, T.; Guenther, R.W.; Neulen, J.

2004-01-01

Purpose: Fluoroscopically guided transcervical fallopian tube recanalization is recognized as an important step in the workup of female infertility. In the present study, a simplified set of recanalization instruments was tested. Materials and Methods: Forty-two women with infertility and sonographically confirmed or suspected uni- or bilateral tubal occlusion were examined. After vaginal placement of a plastic speculum and fixation of a tenaculum, a 4F glide catheter with a 0.89 mm glidewire was advanced transcervically. After documentation of tubal occlusion by hysterosalpingography, the uterotubal junction was catheterized with the same instruments. Under fluoroscopic guidance, the glidewire was negotiated beyond the intramural portion of the tube. Selective salpingography documented the outcome of the recanalization. Results: Hysterosalpingography confirmed tubal occlusions in 26 of 42 patients (in 12 cases unilateral and in 14 cases bilateral). Fallopian tube recanalization was successful in 23 of 26 patients (technical success rate of 88%). The resulting fertility rate was 30% (7/23), without any ectopic pregnancy. Complications such as tubal perforation, infection, or bleeding did not occur. Tubal catheterization was straightforward and smooth in 17/23 cases. For a hyperflexed uterus (6/23), a curved tip of the catheter was helpful in tubal probing. (orig.)

Fluoroscopic guidance for placing a double lumen endotracheal tube in adults.

Science.gov (United States)

Calenda, Emile; Baste, Jean Marc; Hajjej, Ridha; Rezig, Najiba; Moriceau, Jerome; Diallo, Yaya; Sghaeir, Slim; Danielou, Eric; Peillon, Christophe

2014-09-01

The aim of this study was to assess the right placement of the double lumen endotracheal tube with fluoroscopic guidance, which is used in first intention prior to the fiberscope in our institution. This was a prospective observational study. The study was conducted in vascular and thoracic operating rooms. We enrolled 205 patients scheduled for thoracic surgery, with ASA physical statuses of I (n = 37), II (n = 84), III (n = 80), and IV (n = 4). Thoracic procedures were biopsy (n = 20), wedge (n = 34), culminectomy (n = 6), lobectomy (n = 82), pneumonectomy (n = 4), sympathectomy (n = 9), symphysis (n = 47), and thymectomy (n = 3). The intubation with a double lumen tube was performed with the help of a laryngoscope. Tracheal and bronchial balloons were inflated and auscultation was performed after right and left exclusions. One shot was performed to locate the position of the bronchial tube and the hook. Fluoroscopic guidance was used to relocate the tube in case of a wrong position. When the fluoroscopic guidance failed to position the tube, a fiberscope was used. Perioperative collapse of the lung was assessed by the surgeon during the surgery. Correct fluoroscopic image was obtained after the first attempt in 58.5% of patients therefore a misplaced position was encountered in 41.5%. The fluoroscopic guidance allowed an exact repositioning in 99.5% of cases, and the mean duration of the procedure was 8 minutes. A fiberscope was required to move the hook for one patient. We did not notice a moving of the double lumen endotracheal tube during the surgery. The surgeon satisfaction was 100%. The fluoroscopy evidenced the right position of the double lumen tube and allowed a right repositioning in 99.5% of patients with a very simple implementation. Copyright © 2014. Published by Elsevier B.V.

3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

International Nuclear Information System (INIS)

Dhou, S; Hurwitz, M; Cai, W; Rottmann, J; Williams, C; Wagar, M; Berbeco, R; Lewis, J H; Mishra, P; Li, R; Ionascu, D

2015-01-01

3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we developed and performed initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and used these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparison to ground truth digital and physical phantom images. The performance of 4DCBCT-based and 4DCT-based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery. (paper)

Edge enhancement algorithm for low-dose X-ray fluoroscopic imaging.

Science.gov (United States)

Lee, Min Seok; Park, Chul Hee; Kang, Moon Gi

2017-12-01

Low-dose X-ray fluoroscopy has continually evolved to reduce radiation risk to patients during clinical diagnosis and surgery. However, the reduction in dose exposure causes quality degradation of the acquired images. In general, an X-ray device has a time-average pre-processor to remove the generated quantum noise. However, this pre-processor causes blurring and artifacts within the moving edge regions, and noise remains in the image. During high-pass filtering (HPF) to enhance edge detail, this noise in the image is amplified. In this study, a 2D edge enhancement algorithm comprising region adaptive HPF with the transient improvement (TI) method, as well as artifacts and noise reduction (ANR), was developed for degraded X-ray fluoroscopic images. The proposed method was applied in a static scene pre-processed by a low-dose X-ray fluoroscopy device. First, the sharpness of the X-ray image was improved using region adaptive HPF with the TI method, which facilitates sharpening of edge details without overshoot problems. Then, an ANR filter that uses an edge directional kernel was developed to remove the artifacts and noise that can occur during sharpening, while preserving edge details. The quantitative and qualitative results obtained by applying the developed method to low-dose X-ray fluoroscopic images and visually and numerically comparing the final images with images improved using conventional edge enhancement techniques indicate that the proposed method outperforms existing edge enhancement methods in terms of objective criteria and subjective visual perception of the actual X-ray fluoroscopic image. The developed edge enhancement algorithm performed well when applied to actual low-dose X-ray fluoroscopic images, not only by improving the sharpness, but also by removing artifacts and noise, including overshoot. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical application of percutaneous gastrostomy and gastrojejunostomy under fluoroscopic guidance

International Nuclear Information System (INIS)

Zhou Jianping; Wang Zhongmin; Liu Tao; Chen Kemin; Gong Ju; Zheng Yunfeng; Chen Zhijin; Shen Jieyun

2011-01-01

Objective: To evaluate the safety and effectiveness of percutaneous gastrostomy (PRG) and gastrojejunostomy (PRGJ) under fluoroscopic guidance, and to discuss its technical manipulation, the indications and contraindications as well as the complications. Methods: During the period from May 2002 to June 2010 in authors' hospital fluoroscopically-guided PRG or PRGJ was carried out in 40 patients. The clinical data were retrospectively analyzed. With Seldinger technique and under fluoroscopic guidance, a 14 F radiopaque gastrostomy or gastrojejunostomy feeding catheter was successfully placed. The indications, operation procedures, clinical success rate, procedure-related complications, and tube indwelling time, etc. were discussed and analyzed. Results: PRG was conducted in 30 patients. The reasons for performing PRG included neurologic disease (n=13), recurrent aspiration pneumonia (n=6), gastroesophageal reflux due to disfunction of gastrointestinal tract (n=3), subtotal gastrectomy (n=2), esophagomediastinal fistula (n=1) and esophageal carcinoma (n=5). PRGJ was carried out in 10 patients. The disorders included bulbar paralysis (n=3), malignant duodenal obstruction (n=4) and previous gastrostomy-related complications (n=3). Two anchors were used in all patients receiving PRG or PRGJ. Clinical success was achieved in all study patients. No procedure-related or severe complications occurred. Minor complications were observed in four patients (10%), which included local soft tissue infection (n=1), severe puncture site pain (n=1), gastrostomy tube dislodgement (n=1) and obstruction of gastrojejunostomy tube (n=1). During the follow-up period, no aggravation of gastroesophageal reflux or aspiration pneumonia was observed in all patients. The tube indwelling time was 115 to 585 days (mean of 150 days) after tube placement. Conclusion: Fluoroscopically-guided percutaneous gastrostomy or gastrojejunostomy is a safe, simple and minimally-invasive technique. This

Relationship between source-surface distance and patient dose in fluoroscopic X-ray examinations

International Nuclear Information System (INIS)

Suzuki, Shoichi; Asada, Yasuki; Nishi, Kazuta; Mizuno, Emiko; Hara, Natsue; Orito, Takeo; Kamei, Tetsuya; Koga, Sukehiko

2000-01-01

The International Electrotechnical Commission, IEC provided in its standard IEC 60601-1-3 (1994) to prevent the use during radioscopic irradiation of focal spot to skin distances less than 20 cm if the X-RAY EQUIPMENT is specified for RADIOSCOPY during surgery or 30 cm for other specified applications. This standard was reflected in the Japanese Industrial Standard JIS Z 4701-1997, which provided the minimum distance from focal spot to skin to be 30 cm for the use of a fluoroscopic and radiographic table (Under-table type). However, JIS had formerly provided the minimum distance to be 40 cm and so does the current Medical Treatment Law. The draft revision for the Medical Treatment Law currently discussed has consideration to adopt the value 30 cm in accordance with the current JIS. Our research intended to investigate the impact on the entrance surface dose for the change of the focal spot to skin distance from 40 cm to 30 cm. The result was 20-30% increase of the entrance surface dose for the focal spot to skin distance 30 cm. Taking patient exposure dose into account, we need further and more sufficient discussion with this result before adopting this value to the Medical Treatment Law. (author)

[Computer optical topography: a study of the repeatability of the results of human body model examination].

Science.gov (United States)

Sarnadskiĭ, V N

2007-01-01

The problem of repeatability of the results of examination of a plastic human body model is considered. The model was examined in 7 positions using an optical topograph for kyphosis diagnosis. The examination was performed under television camera monitoring. It was shown that variation of the model position in the camera view affected the repeatability of the results of topographic examination, especially if the model-to-camera distance was changed. A study of the repeatability of the results of optical topographic examination can help to increase the reliability of the topographic method, which is widely used for medical screening of children and adolescents.

Cryo-balloon catheter localization in fluoroscopic images

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Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2013-03-01

Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

Radiofrequency catheter ablation: Relationship between fluoroscopic time and skin doses according to diagnoses. Basis to establish a quality assurance programme

International Nuclear Information System (INIS)

Cotelo, E.; Pouso, J.; Reyes, W.

2001-01-01

Radiofrequency Cardiac Catheter Ablation is an Interventional Radiology procedure of great complexity because the cardiologist needs a simultaneous evaluation of fluoroscopic images and electrophysiologic information. Therefore, the procedure typically involves extended fluoroscopic time that may cause radiation-skin injures to patients. Skin doses depend on many factors: equipment design features and its proper use, cardiologist practice, fluoroscopic time, irradiated areas, application of radiation protection recommendations, etc. We evaluate fluoroscopic time in relation to pathology and we estimate skin doses on 233 procedures at the Electrophysiology Laboratory in Casa de Galicia, Montevideo, Uruguay. Significant differences among the medians of fluoroscopic time were found in those procedures depending on diagnoses and results. Higher fluoroscopic time was found in flutter and auricular tachycardia (median was 83 minutes, p=0.0001). In successful procedures (almost 90%), median skin doses was 2.0 Grays (p=0.0001). On the basis of records information, the standard operating procedure and the clinical protocol, expanding close cooperation between the cardiologists and the experts in Radiation Protection will secure the establishment of an Assurance Quality Program. (author)

Management of pediatric radiation dose using GE fluoroscopic equipment

International Nuclear Information System (INIS)

Belanger, Barry; Boudry, John

2006-01-01

In this article, we present GE Healthcare's design philosophy and implementation of X-ray imaging systems with dose management for pediatric patients, as embodied in its current radiography and fluoroscopy and interventional cardiovascular X-ray product offerings. First, we present a basic framework of image quality and dose in the context of a cost-benefit trade-off, with the development of the concept of imaging dose efficiency. A set of key metrics of image quality and dose efficiency is presented, including X-ray source efficiency, detector quantum efficiency (DQE), detector dynamic range, and temporal response, with an explanation of the clinical relevance of each. Second, we present design methods for automatically selecting optimal X-ray technique parameters (kVp, mA, pulse width, and spectral filtration) in real time for various clinical applications. These methods are based on an optimization scheme where patient skin dose is minimized for a target desired image contrast-to-noise ratio. Operator display of skin dose and Dose-Area Product (DAP) is covered, as well. Third, system controls and predefined protocols available to the operator are explained in the context of dose management and the need to meet varying clinical procedure imaging demands. For example, fluoroscopic dose rate is adjustable over a range of 20:1 to adapt to different procedure requirements. Fourth, we discuss the impact of image processing techniques upon dose minimization. In particular, two such techniques, dynamic range compression through adaptive multiband spectral filtering and fluoroscopic noise reduction, are explored in some detail. Fifth, we review a list of system dose-reduction features, including automatic spectral filtration, virtual collimation, variable-rate pulsed fluoroscopic, grid and no-grid techniques, and fluoroscopic loop replay with store. In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an

Scale-space for empty catheter segmentation in PCI fluoroscopic images.

Science.gov (United States)

Bacchuwar, Ketan; Cousty, Jean; Vaillant, Régis; Najman, Laurent

2017-07-01

In this article, we present a method for empty guiding catheter segmentation in fluoroscopic X-ray images. The guiding catheter, being a commonly visible landmark, its segmentation is an important and a difficult brick for Percutaneous Coronary Intervention (PCI) procedure modeling. In number of clinical situations, the catheter is empty and appears as a low contrasted structure with two parallel and partially disconnected edges. To segment it, we work on the level-set scale-space of image, the min tree, to extract curve blobs. We then propose a novel structural scale-space, a hierarchy built on these curve blobs. The deep connected component, i.e. the cluster of curve blobs on this hierarchy, that maximizes the likelihood to be an empty catheter is retained as final segmentation. We evaluate the performance of the algorithm on a database of 1250 fluoroscopic images from 6 patients. As a result, we obtain very good qualitative and quantitative segmentation performance, with mean precision and recall of 80.48 and 63.04% respectively. We develop a novel structural scale-space to segment a structured object, the empty catheter, in challenging situations where the information content is very sparse in the images. Fully-automatic empty catheter segmentation in X-ray fluoroscopic images is an important and preliminary step in PCI procedure modeling, as it aids in tagging the arrival and removal location of other interventional tools.

Contrast media for fluoroscopic examinations of the GI and GU tracts: current challenges and recommendations.

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Federle, Michael P; Jaffe, Tracy A; Davis, Peter L; Al-Hawary, Mahmoud M; Levine, Marc S

2017-01-01

One of the significant challenges facing radiologists who perform and interpret studies of the gastrointestinal and genitourinary systems have been periodic interruptions in the availability of barium and iodinated contrast media specially formulated for gastrointestinal (GI) and genitourinary (GU) studies. These interruptions are due to the US Food and Drug Administration's recent requirement for more stringent documentation of the safety and efficacy of contrast media and the consolidation among contrast manufacturers. Therefore, radiologists may be required to recommend an alternative means of evaluation, such as computed tomography, magnetic resonance, or endoscopy, or they may need to substitute a different formulation of a contrast agent not specifically developed for GI or GU use, for example the utilization of an agent designed and marketed for vascular use. This article reviews the current status of fluoroscopic contrast media, and provides suggestions and recommendations for the optimal and alternative use of contrast media formulations.

Fluoroscopic dose reduction by acquisition frame rate reduction and image processing

International Nuclear Information System (INIS)

Fritz, S.L.; Mirvis, S.E.; Pals, S.O.

1986-01-01

A new design for fluoroscopic exposure reduction incorporates pulsed x-ray exposure, progressive scan video acquisition at frame rates below 30 Hz, interlaced video display at 30 Hz, and a video rate image processing. To evaluate this design, a variety of phantom systems have been developed to measure the impact of low frame rate pulsed digital fluoroscopy on the performance of several clinical tasks (e.g., catheter placement). The authors are currently using these phantoms with a digital fluoroscopy system using continuous x-ray, interlaced video acquisition and variable acquisition frame rate. The design of their target digital fluoroscopic system, sample image sequences, and the results of some preliminary phantom studies are reported

Experiences upgrading a fluoroscopic system to digital specifications

International Nuclear Information System (INIS)

Fox, T.; Fenzl, G.

1995-01-01

In 1993, an undertable fluoroscopic system was retrofitted with a Fluorospot HC digital system at the radiological clinic of the Knappschaftskrankenhaus in Puettlingen, Germany. The experiences and possibilities resulting from this digital upgrade are related by the authors, whose narrative is also accompanied by examples of clinical images. The costs involved are also discussed in this article. (orig.)

Adjustable radiation protection device of the fluoroscope DG 10

International Nuclear Information System (INIS)

Hoermann, D.

1980-01-01

In cooperation with the 'VEB Transformatoren- und Roentgenwerk Hermann Matern', Dresden, an adjustable radiation protection device has been developed. This supplementary equipment for fluoroscopes ensures a sufficient protection of the gonads against undesirable X radiation, can be handled easily and does not annoy patients, esp. children

SU-D-209-02: Percent Depth Dose Curves for Fluoroscopic X-Ray Beam Qualities Incorporating Copper Filtration

Energy Technology Data Exchange (ETDEWEB)

Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation was to quantify percent depth dose (PDD) curves for fluoroscopic x-ray beam qualities incorporating added copper filtration. Methods: A PTW (Freiburg, Germany) MP3 water tank was used with a Standard Imaging (Middleton, WI) Exradin Model 11 Spokas Chamber to measure PDD curves for 60, 80, 100 and 120 kVp x-ray beams with copper filtration ranging from 0.0–0.9 mm at 22cm and 42cm fields of view from 0 to 150 mm of water. A free-in-air monitor chamber was used to normalize the water tank data to fluctuations in output from the fluoroscope. The measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope. The fluoroscope was inverted from the typical orientation providing an x-ray beam originating from above the water tank. The water tank was positioned so that the water level was located at 60cm from the focal spot; which also represents the focal spot to interventional reference plane distance for that fluoroscope. Results: PDDs for 60, 80, 100, and 120 kVp with 0 mm of copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)] for those beam qualities given differences in fluoroscopes, geometric orientation, type of ionization chamber, and the water tank used for data collection. PDDs for 60, 80, 100, and 120 kVp with copper filtration were obtained and are presented, which have not been previously investigated and published. Conclusion: The equipment and processes used to acquire the reported data were sound and compared well with previously published data for PDDs without copper filtration. PDD data for the fluoroscopic x-ray beams incorporating copper filtration can be used as reference data for estimating organ or soft tissue dose at depth involving similar beam qualities or for comparison with mathematical models.

Fluoroscopic guidance of retrograde exchange of ureteral stents in women.

Science.gov (United States)

Chang, Ruey-Sheng; Liang, Huei-Lung; Huang, Jer-Shyung; Wang, Po-Chin; Chen, Matt Chiung-Yu; Lai, Ping-Hong; Pan, Huay-Ben

2008-06-01

The purpose of this study was to review our experience with fluoroscopically guided retrograde exchange of ureteral stents in women. During a 48-month period, 28 women (age range, 38-76 years) were referred to our department for retrograde exchange of a ureteral stent. The causes of urinary obstruction were tumor compression in 26 patients and benign fibrotic stricture in two patients. A large-diameter snare catheter (25-mm single loop or 18- to 35-mm triple loop) or a foreign body retrieval forceps (opening width, 11.3 mm) was used to grasp the bladder end of the stent under fluoroscopic guidance. The technique entailed replacement of a patent or occluded ureteral stent with a 0.035- or 0.018-inch guidewire with or without the aid of advancement of an angiographic sheath. A total of 54 ureteral stents were exchanged with a snare catheter in 42 cases or a forceps in 12 cases. One stent misplaced too far up the ureter was replaced successfully through antegrade percutaneous nephrostomy. Ten occluded stents, including one single-J stent, were managed with a 0.018-inch guidewire in three cases, advancement of an angiographic sheath over the occluded stent into the ureter in five cases, and recannulation of the ureteral orifice with a guidewire in two cases. No complications of massive hemorrhage, ureter perforation, or infection were encountered. With proper selection of a snare or forceps catheter, retrograde exchange of ureteral stents in women can be easily performed under fluoroscopic guidance with high technical success and a low complication rate.

Validation of Diagnostic Imaging Based on Repeat Examinations. An Image Interpretation Model

International Nuclear Information System (INIS)

Isberg, B.; Jorulf, H.; Thorstensen, Oe.

2004-01-01

Purpose: To develop an interpretation model, based on repeatedly acquired images, aimed at improving assessments of technical efficacy and diagnostic accuracy in the detection of small lesions. Material and Methods: A theoretical model is proposed. The studied population consists of subjects that develop focal lesions which increase in size in organs of interest during the study period. The imaging modality produces images that can be re-interpreted with high precision, e.g. conventional radiography, computed tomography, and magnetic resonance imaging. At least four repeat examinations are carried out. Results: The interpretation is performed in four or five steps: 1. Independent readers interpret the examinations chronologically without access to previous or subsequent films. 2. Lesions found on images at the last examination are included in the analysis, with interpretation in consensus. 3. By concurrent back-reading in consensus, the lesions are identified on previous images until they are so small that even in retrospect they are undetectable. The earliest examination at which included lesions appear is recorded, and the lesions are verified by their growth (imaging reference standard). Lesion size and other characteristics may be recorded. 4. Records made at step 1 are corrected to those of steps 2 and 3. False positives are recorded. 5. (Optional) Lesion type is confirmed by another diagnostic test. Conclusion: Applied on subjects with progressive disease, the proposed image interpretation model may improve assessments of technical efficacy and diagnostic accuracy in the detection of small focal lesions. The model may provide an accurate imaging reference standard as well as repeated detection rates and false-positive rates for tested imaging modalities. However, potential review bias necessitates a strict protocol

Common fluoroscopic studies in radiology : conduct and analysis method

International Nuclear Information System (INIS)

Valverde Sanchez, Allan

2011-01-01

A countless number of radiological procedures, that have involved the use of fluoroscopy and contrast media of different indole, have been carried out in all radiology services and medical images of Costa Rica for the diagnosis of diseases or conditions, in both adults and in children. Fluoroscopic studies, often called special or contrast studies, have had particular conditions for its realization. Some from the medical point of view: adequate training in the technical and cognitive development when evaluating the images to not miss important details. Other by the patient: adequate preparation to achieve the best images for optimal diagnosis. For example, adequate bowel preparation is essential for a barium enema, to cooperation by the patient to meet specific indications that the physician dictates when swallowing postures or just when you are prompted. Criteria have been met and unified for contrast studies in different hospitals and clinics. The indications, contra, method, technique of procedure, points to remember, number of images or projections minimum required in the interpretation of contrast studies, as well as a report template of standard and ideal study are presented in a simple, systematic and logical. The manual is intended for residents and attending physicians specialists in radiology and medical imaging including contrast studies more common. Spaces are promoted with current technology studies to set aside more complicated and less sophisticated as have been the fluoroscopic studies; however, in the national reality, access to computerized tomography and magnetic resonance imaging is not as easy. Radiological studies with fluoroscopy performed by trained staff led the treating physician to make sound decisions based on studies relatively simple and easy to do. The tests with the use of fluoroscopic have been named: the esophagogram, gastroduodenal series, gastro intestinal transit, the hysterosalpingography, the cystography and the

Role of fluoroscopic guided self expandable metallic stents in the management of malignant esophageal strictures

OpenAIRE

Mohamed Shaker; Ahmed Deif; Amr Abdelaal

2016-01-01

Objectives: To evaluate the role of fluoroscopic guided self expanding metallic stents in the management of dysphagia caused by malignant esophageal strictures. Materials and methods: During the period between April 2010 and October 2012, 31 patients with malignant esophageal strictures were subjected to fluoroscopic guided self expanding metallic stent application. The study included 22 males and 9 females ranging in age between 22 and 75 years old with mean age of 56.8 years. Lesions wer...

Measurements for testing of fluoroscopic screens, including the photofluorographic units

International Nuclear Information System (INIS)

Balfanz, R.

1986-01-01

Image quality control measurements for fluoroscopic screens and photofluorographs have shown that both types of equipment have a long operating life, so that constancy and technical performance tests are absolutely necessary. It is recommended to conclude in-service maintenance contracts with the manufacturers. (DG) [de

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

Science.gov (United States)

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

2018-02-01

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

Fluoroscopic tomography. [for body section synthesis

Science.gov (United States)

Baily, N. A.; Crepeau, R. L.; Lasser, E. C.

1974-01-01

A fluoroscopic tomography system capable of synthesizing body sections at a number of levels within the body has been developed. The synthesized body sections may lie either in a range of planes parallel to, tilted with respect to, skewed with respect to, or both tilted and skewed with respect to the plane of motion of the X-ray tube target. In addition, body sections can be presented which are contoured to the patient's anatomy. That is to say, they may even encompass such complex surfaces as a quadratic hyperplane. In addition, tomograms of organs in motion can be imaged.

Fluoroscopically-guided foam sclerotherapy with sodium morrhuate for the treatment of lower extremity varices

International Nuclear Information System (INIS)

Wang Haiting; Jiang Zhongpu; Zhou Yi

2011-01-01

Objective: To evaluate fluoroscopically-guided foam sclerotherapy with injection of domestic sodium morrhuate in treating lower extremity varices. Methods: A total of 30 cases (39 diseased lower limbs) with lower extremity varices were enrolled in this study. Under fluoroscopic guidance foam sclerotherapy with injection of domestic sodium morrhuate was carried out in all patients. The obstructed condition of the great saphenous vein was observed during the following three months. Results: The technical success was achieved in all 39 patients. The mean dose of foam sclerosant used for each diseased limb was 5.9 ml (3.4-8.2 ml). Disappearance of blood flow reflux in lower extremity vein immediately after the treatment was seen in 35 patients (90%). Three months after the therapy, vascular sonography showed that the great saphenous vein was obstructed, and no serious complications occurred. Conclusion: For the treatment of lower extremity varices, fluoroscopically-guided foam sclerotherapy with injection of domestic sodium morrhuate is safe and effective with satisfactory results. This technique is a newly-developed micro-invasive therapy for lower extremity varices. (authors)

The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method

International Nuclear Information System (INIS)

Bender, Greg N.; Mullins, Daniel J.; Makuch, Richard S.

1999-01-01

Purpose: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. Materials and methods: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. Results: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89% whereas the sensitivity of greater curvature biopsy is 62%. The difference is considered clinically significant at P≤0.05. Conclusions: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy

The need for using fluoroscopic guidance to obtain gastric biopsies when in search of Helicobacter pylori with a nonendoscopic method

Energy Technology Data Exchange (ETDEWEB)

Bender, Greg N.; Mullins, Daniel J.; Makuch, Richard S

1999-12-01

Purpose: Nonendoscopic, fluoroscopic biopsy of the gastric mucosa, following barium examination of the stomach, has gained attention with its ease of performance and cost savings potential over endoscopy. Endoscopic research concerning the efficacy of biopsy sites has revealed an increased sensitivity of antral biopsies over greater curvature biopsies for the detection of Helicobacter pylori. Fluoroscopically guided biopsies of the gastric mucosal are studied to determine whether such a difference between site sensitivity held true. If not, blind biopsy through a nasogastric tube, which traditionally samples only the greater curvature, might prove an even less expensive alternative. Materials and methods: Seventy-two patients underwent nonendoscopic, fluoroscopically guided, mucosal biopsy of both the gastric antrum and the greater curvature of the stomach. Pathologic reports from both sites, using each patient as their own control, are compared to assess site sensitivity in the diagnosis of H. pylori gastritis. Results: The sensitivity for the detection of H. pylori gastritis by antral biopsy is 89% whereas the sensitivity of greater curvature biopsy is 62%. The difference is considered clinically significant at P{<=}0.05. Conclusions: This study confirms the need for antral biopsies when desiring a nonendoscopic approach to gastric mucosal sampling, in order to obtain a reasonable yield of data in dyspeptic patients with H. pylori gastritis. Blind techniques cannot reliably reach the antrum. Fluoroscopy can, and remains a less expensive alternative to endoscopy.

A study of the x-ray image quality improvement in the examination of the respiratory system based on the new image processing technique

Science.gov (United States)

Nagai, Yuichi; Kitagawa, Mayumi; Torii, Jun; Iwase, Takumi; Aso, Tomohiko; Ihara, Kanyu; Fujikawa, Mari; Takeuchi, Yumiko; Suzuki, Katsumi; Ishiguro, Takashi; Hara, Akio

2014-03-01

Recently, the double contrast technique in a gastrointestinal examination and the transbronchial lung biopsy in an examination for the respiratory system [1-3] have made a remarkable progress. Especially in the transbronchial lung biopsy, better quality of x-ray fluoroscopic images is requested because this examination is performed under a guidance of x-ray fluoroscopic images. On the other hand, various image processing methods [4] for x-ray fluoroscopic images have been developed as an x-ray system with a flat panel detector [5-7] is widely used. A recursive filtering is an effective method to reduce a random noise in x-ray fluoroscopic images. However it has a limitation for its effectiveness of a noise reduction in case of a moving object exists in x-ray fluoroscopic images because the recursive filtering is a noise reduction method by adding last few images. After recursive filtering a residual signal was produced if a moving object existed in x-ray images, and this residual signal disturbed a smooth procedure of the examinations. To improve this situation, new noise reduction method has been developed. The Adaptive Noise Reduction [ANR] is the brand-new noise reduction technique which can be reduced only a noise regardless of the moving object in x-ray fluoroscopic images. Therefore the ANR is a very suitable noise reduction method for the transbronchial lung biopsy under a guidance of x-ray fluoroscopic images because the residual signal caused of the moving object in x-ray fluoroscopic images is never produced after the ANR. In this paper, we will explain an advantage of the ANR by comparing of a performance between the ANR images and the conventional recursive filtering images.

Real-Time Verification of a High-Dose-Rate Iridium 192 Source Position Using a Modified C-Arm Fluoroscope

Energy Technology Data Exchange (ETDEWEB)

Nose, Takayuki, E-mail: nose-takayuki@nms.ac.jp [Department of Radiation Oncology, Nippon Medical School Tamanagayama Hospital, Tama (Japan); Chatani, Masashi [Department of Radiation Oncology, Osaka Rosai Hospital, Sakai (Japan); Otani, Yuki [Department of Radiology, Kaizuka City Hospital, Kaizuka (Japan); Teshima, Teruki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Kumita, Shinichirou [Department of Radiology, Nippon Medical School Hospital, Tokyo (Japan)

2017-03-15

Purpose: High-dose-rate (HDR) brachytherapy misdeliveries can occur at any institution, and they can cause disastrous results. Even a patient's death has been reported. Misdeliveries could be avoided with real-time verification methods. In 1996, we developed a modified C-arm fluoroscopic verification of an HDR Iridium 192 source position prevent these misdeliveries. This method provided excellent image quality sufficient to detect errors, and it has been in clinical use at our institutions for 20 years. The purpose of the current study is to introduce the mechanisms and validity of our straightforward C-arm fluoroscopic verification method. Methods and Materials: Conventional X-ray fluoroscopic images are degraded by spurious signals and quantum noise from Iridium 192 photons, which make source verification impractical. To improve image quality, we quadrupled the C-arm fluoroscopic X-ray dose per pulse. The pulse rate was reduced by a factor of 4 to keep the average exposure compliant with Japanese medical regulations. The images were then displayed with quarter-frame rates. Results: Sufficient quality was obtained to enable observation of the source position relative to both the applicators and the anatomy. With this method, 2 errors were detected among 2031 treatment sessions for 370 patients within a 6-year period. Conclusions: With the use of a modified C-arm fluoroscopic verification method, treatment errors that were otherwise overlooked were detected in real time. This method should be given consideration for widespread use.

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

International Nuclear Information System (INIS)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark

1997-01-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)

1997-11-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

Fluoroscopic-guided covered metallic stent placement for gastric outlet obstruction and post-operative gastroenterostomy anastomotic stricture

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Young; Lee, Soo Teik; Yang, Doo Hyun

2001-07-01

AIM: To evaluate the feasibility and safety of fluoroscopic-guided covered metallic stent placements in providing palliative care for patients with inoperable malignant gastric outlet obstruction. MATERIALS AND METHODS: Under fluoroscopic guidance, placement of self-expandable, covered stents was attempted in 20 patients with inoperable or recurrent gastric cancer (age range 36-79 years). All patients had inoperable gastric outlet obstruction, 13 with native anatomy and seven with post-operative anatomy (gastrointestinal anastomotic sites). All patients had intolerance to oral alimentation and/or vomiting after ingestion. Success was defined both technically and clinically. RESULTS: The placement of the stent was technically successful in 18 patients and failed in two patients (technical success: 90%). The cause of the technical failures was an inability to negotiate the guide wire through the obstruction sites in spite of the use of both fluoroscopic and endoscopic guidance. After stent placement, 15 patients were able to ingest at least liquids and had a markedly decreased incidence of vomiting (clinical success: 75%). During the mean follow-up of 6 weeks, there have been no stent reocclusion and no life-threatening complications except migration of two stents in one patient. CONCLUSION: Fluoroscopically guided covered metallic stent placement appears to be valuable for the palliative treatment of malignant obstruction of gastric outlet and post-operative gastrointestinal anastomoses. Lee, J.M. et al. (2001)

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

Science.gov (United States)

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

2016-06-01

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

Problems of dentistrical prophylactic medical examination of persons dealing with ionizing radiation sources

International Nuclear Information System (INIS)

Kalinin, V.I.; Ramzaeva, L.V.; Zamanova, L.V.

1988-01-01

A comparative study of data of individual dosimetric control of radiological personnel and additional radiation contribution of annual fluoroscopy of chest into radiation load was carried out. It is stated that chest fluoroscopy adds 13 % of collective dose to the occupational irradiation. Efficiency of preventive chest fluoroscopic examination was simultaneously analyzed in 1388 persons engaged in occupational radiology. Investigation results permit to state a question on advisability of transition to differential chest fluoroscopic examination in persons of A category, being guided by clinical indications and potential risk of carcinogenesis and tuberculosis. 5 refs

Use of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement

International Nuclear Information System (INIS)

Bae, Jae-Ik; Shin, Ji Hoon; Song, Ho-Young; Yoon, Chang Jin; Nam, Deok Ho; Choi, Won-Chan; Lim, Jin-Oh

2005-01-01

Our purpose was to assess the safety and usefulness of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement. Two types of guiding sheath were made from straight polytetrafluoroethylene tubes. Type A was 80 cm in length, 4 mm in outer diameter and 3 mm in inner diameter. Type B was 70 cm in length, 6 mm in outer diameter and 5 mm in inner diameter. The type A sheath was used in 18 patients in whom a catheter-guide wire combination failed to pass through a stricture. The type B sheath was used in 22 patients in whom a stent delivery system failed to pass through the stricture due to loop formation within the gastric lumen. The overall success rate for guiding a catheter-guide wire through a stricture after using the type A sheath was 89%. The overall success rate for passing a stent delivery system through a stricture after using the type B sheath was 100%. All procedures were tolerated by the patients without any significant complications. The guiding sheaths were safe and useful in peroral fluoroscopic gastroduodenal stent placement. (orig.)

Short-term outcome of fluoroscopic-guided steroid injection therapy of lumber facet cyst-induced radicular pain

Energy Technology Data Exchange (ETDEWEB)

Kwon, Mi Ri; Kwon, Jong Won; Lee, Jong Seo; Kim, Eu Sang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2015-04-15

To determine the short-term effect of fluoroscopic-guided steroid injection therapy of lumbar facet cyst-induced radicular pain. Seventeen patients with radiculopathy due to lumbar synovial cysts, who were treated with fluoroscopically guided injection, were retrospectively evaluated. All plain radiographic images and MR images before the therapy were reviewed. Five patients underwent only the facet joint injection, whereas twelve patients underwent the facet joint injection with perineural injection therapy. The clinical course of pain was evaluated on the first follow-up after therapy. Effective pain relief was achieved in 11 (64.7%) of the 17 patients. Among 12 patients who underwent facet joint injection with perineural injection, 9 patients (75%) had an effective pain relief. Of 5 patients, 2 (40%) patients only took the facet joint injection and had an effective pain relief. Fluoroscopic-guided steroid injection therapy shows a good short-term effect in patients with symptomatic lumbar facet joint synovial cysts.

Image quality evaluation and patient dose assessment of medical fluoroscopic X-ray systems: A national study

International Nuclear Information System (INIS)

Economides, S.; Hourdakis, C. J.; Kalivas, N.; Kalathaki, M.; Simantirakis, G.; Tritakis, P.; Manousaridis, G.; Vogiatzi, S.; Kipouros, P.; Boziari, A.; Kamenopoulou, V.

2008-01-01

This study presents the results from a survey conducted by the Greek Atomic Energy Commission (GAEC), during the period 1998-2003, in 530 public and private owned fluoroscopic X-ray systems in Greece. Certain operational parameters for conventional and remote control systems were assessed, according to a quality control protocol developed by GAEC on the basis of the current literature. Public (91.5%) and private (81.5%) owned fluoroscopic units exhibit high-contrast resolution values over 1 lp mm -1 . Moreover, 88.5 and 87.1% of the fluoroscopic units installed in the public and private sector, respectively, present Maximum Patient Entrance Kerma Rate values lower than 100 mGy min -1 . Additionally, 68.3% of the units assessed were found to perform within the acceptance limits. Finally, the third quartile of the Entrance Surface Dose Rate distribution was estimated according to the Dose Reference Level definition and found equal to 35 mGy min -1 . (authors)

MO-F-CAMPUS-I-02: Occupational Conceptus Doses From Fluoroscopically-Guided Interventional Procedures

Energy Technology Data Exchange (ETDEWEB)

Damilakis, J; Perisinakis, K; Solomou, G [University of Crete (Greece); Stratakis, J [University of Crete, Heraklion, Crete (Greece)

2015-06-15

Purpose: The aim of this method was to provide dosimetric data on conceptus dose for the pregnant employee who participates in fluoroscopically-guided interventional procedures. Methods: Scattered air-kerma dose rates were obtained for 17 fluoroscopic projections involved in interventional procedures. These projections were simulated on an anthropomorphic phantom placed on the examination table supine. The operating theater was divided into two grids relative to the long table sides. Each grid consisted of 33 cells spaced 0.50 m apart. During the simulated exposures, at each cell, scatter air-kerma rate was measured at 110 cm from the floor i.e. at the height of the waist of the pregnant worker. Air-kerma rates were divided by the dose area product (DAP) rate of each exposure to obtain normalized data. For each projection, measurements were performed for 3 kVp and 3 filtration values i.e. for 9 different x-ray spectra. All measurements were performed by using a modern C-arm angiographic system (Siemens Axiom Artis, Siemens, Germany) and a radiation meter equipped with an ionization chamber. Results: The results consist of 153 iso-dose maps, which show the spatial distribution of DAP-normalized scattered air-kerma doses at the waist level of a pregnant worker. Conceptus dose estimation is possible using air-kerma to embryo/fetal dose conversion coefficients published in a previous study (J Cardiovasc Electrophysiol, Vol. 16, pp. 1–8, July 2005). Using these maps, occupationally exposed pregnant personnel may select a working position for a certain projection that keeps abdominal dose as low as reasonably achievable. Taking into consideration the regulatory conceptus dose limit for occupational exposure, determination of the maximum workload allowed for the pregnant personnel is also possible. Conclusion: Data produced in this work allow for the anticipation of conceptus dose and the determination of the maximum workload for a pregnant worker from any

MO-F-CAMPUS-I-02: Occupational Conceptus Doses From Fluoroscopically-Guided Interventional Procedures

International Nuclear Information System (INIS)

Damilakis, J; Perisinakis, K; Solomou, G; Stratakis, J

2015-01-01

Purpose: The aim of this method was to provide dosimetric data on conceptus dose for the pregnant employee who participates in fluoroscopically-guided interventional procedures. Methods: Scattered air-kerma dose rates were obtained for 17 fluoroscopic projections involved in interventional procedures. These projections were simulated on an anthropomorphic phantom placed on the examination table supine. The operating theater was divided into two grids relative to the long table sides. Each grid consisted of 33 cells spaced 0.50 m apart. During the simulated exposures, at each cell, scatter air-kerma rate was measured at 110 cm from the floor i.e. at the height of the waist of the pregnant worker. Air-kerma rates were divided by the dose area product (DAP) rate of each exposure to obtain normalized data. For each projection, measurements were performed for 3 kVp and 3 filtration values i.e. for 9 different x-ray spectra. All measurements were performed by using a modern C-arm angiographic system (Siemens Axiom Artis, Siemens, Germany) and a radiation meter equipped with an ionization chamber. Results: The results consist of 153 iso-dose maps, which show the spatial distribution of DAP-normalized scattered air-kerma doses at the waist level of a pregnant worker. Conceptus dose estimation is possible using air-kerma to embryo/fetal dose conversion coefficients published in a previous study (J Cardiovasc Electrophysiol, Vol. 16, pp. 1–8, July 2005). Using these maps, occupationally exposed pregnant personnel may select a working position for a certain projection that keeps abdominal dose as low as reasonably achievable. Taking into consideration the regulatory conceptus dose limit for occupational exposure, determination of the maximum workload allowed for the pregnant personnel is also possible. Conclusion: Data produced in this work allow for the anticipation of conceptus dose and the determination of the maximum workload for a pregnant worker from any

Nonsurgical Fluoroscopically Guided Dacryocystoplasty of Common Canalicular Obstructions

Energy Technology Data Exchange (ETDEWEB)

Wilhelm, Kai E; Hofer, Ulrich; Textor, Hans J [Department of Radiology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany); Boeker, Thorsten [Department of Ophthalmology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany); Strunk, Holger; Schild, Hans H [Department of Radiology, University Hospital Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany)

2000-01-15

Purpose: To assess dacryocystoplasty in the treatment of epiphora due to obstructions of the common canaliculus.Methods: Twenty patients with severe epiphora due to partial (n = 16) or complete (n = 4) obstruction of the common canaliculus underwent fluoroscopically guided dacryocystoplasty. In all cases of incomplete obstruction balloon dilation was performed. Stent implantation was attempted in cases with complete obstruction. Dacryocystography and clinical follow-up was performed at intervals of 1 week, and 3, 6, 12, and 18 months after the procedure. The mean follow-up was 6 months (range 3-18 months).Results: Balloon dilation was technically successfully performed in all patients with incomplete obstructions (n = 16). In three of four patients with complete obstruction stent implantation was performed successfully. Subsequent to failure of stent implantation in one of these patients balloon dilation was performed instead. The long-term primary patency rate in patients with incomplete obstructions was 88% (n = 14/16). In three of four cases with complete obstruction long-term patency was achieved during follow-up. Severe complications, infections, or punctal splitting were not observed.Conclusion: Fluoroscopically guided balloon dacryocystoplasty is a feasible nonsurgical therapy in canalicular obstructions with good clinical results that may be used as an alternative to surgical procedures. In patients with complete obstructions stent placement is possible but further investigations are needed to assess the procedural and long-term results.

Nonsurgical Fluoroscopically Guided Dacryocystoplasty of Common Canalicular Obstructions

International Nuclear Information System (INIS)

Wilhelm, Kai E.; Hofer, Ulrich; Textor, Hans J.; Boeker, Thorsten; Strunk, Holger; Schild, Hans H.

2000-01-01

Purpose: To assess dacryocystoplasty in the treatment of epiphora due to obstructions of the common canaliculus.Methods: Twenty patients with severe epiphora due to partial (n = 16) or complete (n = 4) obstruction of the common canaliculus underwent fluoroscopically guided dacryocystoplasty. In all cases of incomplete obstruction balloon dilation was performed. Stent implantation was attempted in cases with complete obstruction. Dacryocystography and clinical follow-up was performed at intervals of 1 week, and 3, 6, 12, and 18 months after the procedure. The mean follow-up was 6 months (range 3-18 months).Results: Balloon dilation was technically successfully performed in all patients with incomplete obstructions (n = 16). In three of four patients with complete obstruction stent implantation was performed successfully. Subsequent to failure of stent implantation in one of these patients balloon dilation was performed instead. The long-term primary patency rate in patients with incomplete obstructions was 88% (n = 14/16). In three of four cases with complete obstruction long-term patency was achieved during follow-up. Severe complications, infections, or punctal splitting were not observed.Conclusion: Fluoroscopically guided balloon dacryocystoplasty is a feasible nonsurgical therapy in canalicular obstructions with good clinical results that may be used as an alternative to surgical procedures. In patients with complete obstructions stent placement is possible but further investigations are needed to assess the procedural and long-term results

Assessment of patient exposure for barium enema examinations

International Nuclear Information System (INIS)

Bednarek, D.R.; Rudin, S.; Wong, R.

1983-01-01

Methods are described for the assessment of patient exposure during clinical fluoroscopic procedures. Values of the roentgen-area-product (RAP) and their distribution throughout the examination are presented for both single-contrast and double-contrast barium enema studies. The double-contrast procedure was measured to give 50% more radiation to the patient than the single-contrast procedure when the same size optical aperture is used between the intensifier and TV pick-up tube. However, it was possible to decrease the fluoroscopic RAP value by over a factor of two for the double-contrast procedure without an adverse clinical effect by increasing the area of the aperture diaphragm

Percutaneous ethanol injection under interventional radiographic computed tomography-fluoroscopic guidance for the treatment of small hepatocellular carcinomas

Energy Technology Data Exchange (ETDEWEB)

Furuse, Junji; Satake, Mitsuo; Iwasaki, Masahiko; Sekiguchi, Ryuzo; Moriyama, Noriyuki; Yoshino, Masahiro [National Cancer Center, Kashiwa, Chiba (Japan). Hospital East

1998-04-01

Some small hepatocellular carcinoma (HCC) lesions show as tumor stains by dynamic CT, but cannot be detected by ultrasonography. Percutaneous ethanol injection (PEI) is effective for treating small HCC lesions, but lack of adequate visualization of some lesions can limit its use. In this study, interventional radiographic, CT-fluoroscopically-guided PEI was performed as a new method for treating small HCC lesions that were difficult to detect by ultrasonography. Interventional radiographic, CT-fluoroscopically-guided PEI was performed on 11 patients (12 lesions) with HCC lesions measuring 2 cm or less in diameter. A thin needle was introduced into each tumor under CT-fluoroscopic guidance, with injection of contrast medium into the dominant hepatic artery. While lesions were observed using CT-fluoroscopy with the arteriogram, absolute ethanol was injected into the tumors. The ethanol injection rate and volume were monitored by observation of loss of tumor staining during real-time CT angiography. Needle introduction was successful in all 12 lesions, and disappearance of tumor staining was immediately observed on CT images after ethanol injection. Complications noted after treatment were local abdominal pain in all 11 patients, a slight fever in 9 patients, pneumothorax, right pleural effusion, and ascites, each in 1 patient. No other serious complications were observed. Interventional radiographic, CT-fluoroscopically-guided PEI is effective in the treatment of small HCC lesions, which are difficult to show by ultrasonography and treat by conventional PEI. (author)

Role of fluoroscopic guided self expandable metallic stents in the management of malignant esophageal strictures

Directory of Open Access Journals (Sweden)

Mohamed Shaker

2016-09-01

Conclusion: Fluoroscopic guided esophageal stenting is a highly effective and safe method for palliating dysphagia in patients with obstructing esophageal cancer with significant clinical improvement.

Fluoroscopically guided fallopian tube recanalization with a simplified set of instruments; Durchleuchtungsgesteuerte Eileiter-Rekanalisation mit vereinfachtem Instrumentarium

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Schmitz-Rode, T.; Guenther, R.W. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Neulen, J. [Technische Hochschule Aachen (Germany). Frauenklinik fuer gynaekologische Endokrinologie und Reproduktionsmedizin

2004-10-01

Purpose: Fluoroscopically guided transcervical fallopian tube recanalization is recognized as an important step in the workup of female infertility. In the present study, a simplified set of recanalization instruments was tested. Materials and Methods: Forty-two women with infertility and sonographically confirmed or suspected uni- or bilateral tubal occlusion were examined. After vaginal placement of a plastic speculum and fixation of a tenaculum, a 4F glide catheter with a 0.89 mm glidewire was advanced transcervically. After documentation of tubal occlusion by hysterosalpingography, the uterotubal junction was catheterized with the same instruments. Under fluoroscopic guidance, the glidewire was negotiated beyond the intramural portion of the tube. Selective salpingography documented the outcome of the recanalization. Results: Hysterosalpingography confirmed tubal occlusions in 26 of 42 patients (in 12 cases unilateral and in 14 cases bilateral). Fallopian tube recanalization was successful in 23 of 26 patients (technical success rate of 88%). The resulting fertility rate was 30% (7/23), without any ectopic pregnancy. Complications such as tubal perforation, infection, or bleeding did not occur. Tubal catheterization was straightforward and smooth in 17/23 cases. For a hyperflexed uterus (6/23), a curved tip of the catheter was helpful in tubal probing. (orig.)

Video dosimetry: evaluation of X-radiation dose by video fluoroscopic image

International Nuclear Information System (INIS)

Nova, Joao Luiz Leocadio da; Lopes, Ricardo Tadeu

1996-01-01

A new methodology to evaluate the entrance surface dose on patients under radiodiagnosis is presented. A phantom is used in video fluoroscopic procedures in on line video signal system. The images are obtained from a Siemens Polymat 50 and are digitalized. The results show that the entrance surface dose can be obtained in real time from video imaging

Intra-examiner repeatability and agreement in accommodative response measurements.

Science.gov (United States)

Antona, B; Sanchez, I; Barrio, A; Barra, F; Gonzalez, E

2009-11-01

Clinical measurement of the accommodative response (AR) identifies the focusing plane of a subject with respect to the accommodative target. To establish whether a significant change in AR has occurred, it is important to determine the repeatability of this measurement. This study had two aims: First, to determine the intraexaminer repeatability of AR measurements using four clinical methods: Nott retinoscopy, monocular estimate method (MEM) retinoscopy, binocular crossed cylinder test (BCC) and near autorefractometry. Second, to study the level of agreement between AR measurements obtained with the different methods. The AR of the right eye at one accommodative demand of 2.50 D (40 cm) was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18-32 years). The intraexaminer repeatability of the tests, and agreement between them, were estimated by the Bland-Altman method. We determined mean differences (MD) and the 95% limits of agreement [coefficient of repeatability (COR) and coefficient of agreement (COA)]. Nott retinoscopy and BCC offered the best repeatability, showing the lowest MD and narrowest 95% interval of agreement (Nott: -0.10 +/- 0.66 D, BCC: -0.05 +/- 0.75 D). The 95% limits of agreement for the four techniques were similar (COA = +/- 0.92 to +/-1.00 D) yet clinically significant, according to the expected values of the AR. The two dynamic retinoscopy techniques (Nott and MEM) had a better agreement (COA = +/-0.64 D) although this COA must be interpreted in the context of the low MEM repeatability (COR = +/-0.98 D). The best method of assessing AR was Nott retinoscopy. The BCC technique was also repeatable, and both are recommended as suitable methods for clinical use. Despite better agreement between MEM and Nott, agreement among the remaining methods was poor such that their interchangeable use in clinical practice is not recommended.

SU-F-I-76: Fluoroscopic X-Ray Beam Profiles for Spectra Incorporating Copper Filtration

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Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation is to characterize and quantify X-ray beam profiles for fluoroscopic x-ray beam spectra incorporating spectral (copper) filtration. Methods: A PTW (Freiburg, Germany) type 60016 silicon diode detector and PTW MP3 water tank were used to measure X-ray beam profiles for 60, 80, 100 and 120 kVp x-ray beams at five different copper filtration thicknesses ranging from 0–0.9 mm at 22 and 42 cm fields of view and depths of 1, 5, and 10 cm in both the anode-cathode axis (inplane) and cross-plane directions. All measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope inverted from the typical orientation providing an x-ray beam originating from above the water surface with the water level set at 60 cm from the focal spot. Results: X-ray beam profiles for beam spectra without copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. Our data collection benefited from the geometric orientation of the fluoroscope, providing a beam perpendicular to the tank water surface, rather than through a thin side wall as did the previously mentioned study. Profiles for beams with copper filtration were obtained which have not been previously investigated and published. Beam profiles in the anode-cathode axis near the surface and at lower x-ray energy exhibited substantial heel effect, which became less pronounced at greater depth. At higher energy with copper filtration in the beam, the dose falloff out-of-field became less pronounced, as would be anticipated given higher scatter photon energy. Conclusion: The x-ray beam profile data for the fluoroscopic x-ray beams incorporating copper filtration are intended for use as reference data for estimating doses to organs or soft tissue, including fetal dose, involving similar beam qualities or for comparison with mathematical models.

Transrectal Drainage of Deep Pelvic Abscesses Using a Combined Transrectal Sonographic and Fluoroscopic Guidance

International Nuclear Information System (INIS)

Jeong, Kyung Soon; Lee, Eun Jung; Ko, Ji Ho; Joh, Young Duk; Jung, Gyoo Sik

2005-01-01

To evaluate the feasibility and clinical efficacy of transrectal drainage of a deep pelvic abscess using combined transrectal sonographic and fluoroscopic guidance. From March 1995 and August 2004, 17 patients (9 men; 8 women; mean age, 39 years) suffering from pelvic pain, fever and leukocytosis were enrolled in this retrospective study. Ultrasound (US) or computed tomography (CT), which was obtained prior to the procedure, showed pelvic fluid collections that were deemed unapproachable by the percutaneous trans abdominal routes. Transrectal drainage of the pelvic abscess was performed under combined transrectal sonographic and fluoroscopic guidance. The causes of the deep pelvic abscess were postoperative complications (n=7), complications associated with radiation (n=3) and chemotherapy (n=1) as well as unknown causes (n=6). A 7.5-MHz end-firing transrectal US probe with a needle biopsy guide attachment was advanced into the rectum. Once the abscess was identified, a needle was advanced via the biopsy guide and the abscess was punctured. Under US guidance, either a 0.018'or 0.035' guide wire was passed through the needle in the abscess. Under fluoroscopic guidance, the tract was dilated to the appropriate diameter with sequential fascial dilators, and a catheter was placed over the guide wire within the abscess. Clinical success of drainage was determined by a combination closure of the cavity on the follow up images and diminished leukocytosis. The technical and clinical success rate, complications, and patient's discomfort were analyzed. Drainage was technically successful in all patients and there were no serious complications. Surgery was eventually performed in two cases due to fistular formation with the rectum and leakage of the anastomosis site. The procedure was well tolerated in all but one patient who complained of discomfort while the catheter was inserted . The catheter did not interfere with defecation and there was no incidence of catheter

Stochastic risk estimation from medical x-ray diagnostic examinations, 2

International Nuclear Information System (INIS)

Hashizume, Tadashi; Maruyama, Takashi; Noda, Yutaka; Iwai, Kazuo; Tateno, Y.; Nishizawa, Kanae.

1981-01-01

The risks of genetic, leukemia and malignant diseases from medical X-ray diagnostic examinations were estimated using the frequency of radiographic and fluoroscopic exposures per diagnostic examination, child expectancy, leukemia and malignancy significant factors, and using a weighting factor determined on the basis of data concerning the cancer mortality among atomic bomb survivors in Nagasaki and of a recommendation of International Commission of Radiological Protection. The organ or tissue doses with respect to the stochastic risks were determined with ionization chambers and thermoluminescent dosimeters placed at the positions of the organs or tissues in a RANDO woman phantom which was exposed to diagnostic X-rays according to technical factors of typical radiographic and fluoroscopic examinations obtained from a nationwide survey. The resultant risks by age-group and type of radiographic and fluoroscopic examination are tabulated in terms of risk level of 10 -6 . In general, the total risk defined as the sum of genetic, leukemia and malignant risks was a high value for the X-ray diagnosis of digestive organs involving barium meal and barium enema. For example, the total risk for young age-group was 100 to 200 x 10 -6 for the X-ray diagnosis of digestive organs. The total risk from the chest radiography was lower value as compared with the risk from the X-ray diagnosis of other organs or tissues. On the contrary, the risk from the chest tomography was comparable to the risk from the diagnosis of digestive organs. The total risk decreased with increasing of age for every X-ray diagnostic examination. (author)

SU-F-I-75: Half-Value Layer Thicknesses and Homogeneity Coefficients for Fluoroscopic X-Ray Beam Spectra Incorporating Spectral Filtration

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Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation is to quantify various first half-value-layers (HVLs), second HVLs and homogeneity coefficients (HCs) for a state-of-the-art fluoroscope utilizing spectral (copper) filtration. Methods: A Radcal (Monrovia, Ca) AccuPro dosimeter with a 10×6-6 calibrated ionization chamber was used to measure air kerma for radiographic x-ray exposures made on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope operated in the service mode. The ionization chamber was centered in the x-ray beam at 72 cm from the focal spot with a source-to-image-distance of 120 cm. The collimators were introduced to limit the x-ray field to approximately 5 cm × 5 cm at the ionization chamber plane. Type-1100 aluminum filters, in 0.5 mm increments, were used to determine the HVL. Two HVL calculation methods were used, log-linear interpolation and Lambert-W interpolation as described by Mathieu [Med Phys, 38(8), 4546 (2011)]. Multiple measurements were made at 60, 80, 100, 120 kVp at spectral filtration thicknesses of 0, 0.1, 0.3, 0.6 and 0.9 mm. Results: First HVL, second HVL, and HCs are presented for the fluoroscopic x-ray beam spectra indicated above, with nearly identical results from the two interpolation methods. Accuracy of the set kVp was also determined and deviated less than 2%. First HVLs for fluoroscopic x-ray beam spectra without spectral filtration determined in our study were 7%–16% greater than previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. However, the FDA minimum HVL requirements changed since that publication, requiring larger HVLs as of 2006. Additionally, x-ray tube and generator architecture have substantially changed over the last 15 years providing different beam spectra. Conclusion: X-ray beam quality characteristics for state-of-the-art fluoroscopes with spectral filtration have not been published. This study provides reference data which will be useful for defining beam qualities encountered on

C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

Science.gov (United States)

Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

2010-05-01

Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

Dosimetry in endoscopic examinations

International Nuclear Information System (INIS)

Aldred, Martha Aurelia; Paes, Walter Siqueira; Fausto, Agnes M.F.; Nucci, Jose Roberto; Yoshimura, Elisabeth Mateus; Okuno, Emico; Maruta, Luis Massuo

1996-01-01

Equivalent and effective doses in occupational exposures are evaluated considering that some specific endoscopic examinations, radiographic and fluoroscopic images of patients are taken with the medical staff near to the radiation field. Examinations are simulated using an anthropomorphic phantom as a member of the medical staff. Thermoluminescent dosemeters are attached in several positions of the phantom in order to determine some organ doses. From the comparison between the doses experimentally determined and the International and the Brazilian recommended occupational dose limits, the maximum number of examination that any member of the staff can perform was calculated

28 CFR 552.13 - X-ray, major instrument, fluoroscope, or surgical intrusion.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false X-ray, major instrument, fluoroscope, or... INSTITUTIONAL MANAGEMENT CUSTODY Searches of Housing Units, Inmates, and Inmate Work Areas § 552.13 X-ray, major... reasons only, with the inmate's consent. (b) The institution physician may authorize use of an X-ray for...

An engineering development of fluoroscopic X-ray medical equipment based-on fluorescent screen

International Nuclear Information System (INIS)

Ferry Suyatno; I Putu Susila; Djoko Sukmono

2011-01-01

Fluoroscopic x-ray medical equipment uses fluorescent screen to capture structural image of organs. Unlike conventional x-ray equipment which uses film, in the fluoroscopic x-ray, the resulting image is visualized on the fluorescent screen and directly observed by physicians in the patients' rooms. In this study, we developed an image capture system that transforms the image on the fluorescent screen into digital data, which is then transferred to computer for visualization and further processing. By using this system, the observation of the resulting image can be done on a computer that is placed in the control room. The image can also be stored easily and at low cost compared to conventional film. The experiment shows that the system could be used to capture image of the object. However, its quality needs to be improved. In the future, the system will be modified and tested with different types of cameras to obtain better results. (author)

Diagnostic value of the fluoroscopic triggering 3D LAVA technique for primary liver cancer.

Science.gov (United States)

Shen, Xiao-Yong; Chai, Chun-Hua; Xiao, Wen-Bo; Wang, Qi-Dong

2010-04-01

Primary liver cancer (PLC) is one of the common malignant tumors. Liver acquisition with acceleration volume acquisition (LAVA), which allows simultaneous dynamic enhancement of the hepatic parenchyma and vasculature imaging, is of great help in the diagnosis of PLC. This study aimed to evaluate application of the fluoroscopic triggering 3D LAVA technique in the imaging of PLC and liver vasculature. The clinical data and imaging findings of 38 adults with PLC (22 men and 16 women; average age 52 years), pathologically confirmed by surgical resection or biopsy, were collected and analyzed. All magnetic resonance images were obtained with a 1.5-T system (General Electrics Medical Systems) with an eight-element body array coil and application of the fluoroscopic triggering 3D LAVA technique. Overall image quality was assessed on a 5-point scale by two experienced radiologists. All the nodules and blood vessel were recorded and compared. The diagnostic accuracy and feasibility of LAVA were evaluated. Thirty-eight patients gave high quality images of 72 nodules in the liver for diagnosis. The accuracy of LAVA was 97.2% (70/72), and the coincidence rate between the extent of tumor judged by dynamic enhancement and pathological examination was 87.5% (63/72). Displayed by the maximum intensity projection reconstruction, nearly all cases gave satisfactory images of branches III and IV of the hepatic artery. Furthermore, small early-stage enhancing hepatic lesions and the parallel portal vein were also well displayed. Sequence of LAVA provides good multi-phase dynamic enhancement scanning of hepatic lesions. Combined with conventional scanning technology, LAVA effectively and safely displays focal hepatic lesions and the relationship between tumor and normal tissues, especially blood vessels.

Comparison of MR and fluoroscopic mucous fistulography in the pre-operative evaluation of infants with anorectal malformation: a pilot study

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Alves, Jose C.G.; Lotz, Jan W.; Pitcher, Richard D. [Stellenbosch University, Division of Radiodiagnosis, Department of Medical Imaging and Clinical Oncology, Tygerberg Academic Hospital, Cape Town (South Africa); Sidler, Daniel [Stellenbosch University, Division of Pediatric Surgery, Department of Surgical Sciences, Tygerberg Academic Hospital, Cape Town (South Africa)

2013-08-15

Anorectal malformations are often associated with rectal pouch fistulas. Surgical correction requires accurate evaluation of the presence and position of such fistulas. Fluoroscopy is currently the chosen modality for the detection of fistulas. The role of MRI is unexplored. To compare the diagnostic accuracy of MR versus fluoroscopic fistulography in the pre-operative evaluation of infants with anorectal malformation. We conducted a pilot study of infants requiring defunctioning colostomy for initial management of anorectal malformation. Dynamic sagittal steady-state free-precession MRI of the pelvis was acquired during introduction of saline into the mucous fistulas. Findings were compared among MR fistulography, fluoroscopic fistulography and intraoperative inspection. Eight children were included. Median age at fistulography was 15 weeks, inter-quartile range 13-20 weeks; all were boys. There was full agreement among MR fistulography, fluoroscopic fistulography and surgical findings. The pilot data suggest that MR fistulography is promising in the pre-operative evaluation of children with anorectal malformation. (orig.)

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent.

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Full Text Available Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability.

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent.

Science.gov (United States)

List, Renate; Postolka, Barbara; Schütz, Pascal; Hitz, Marco; Schwilch, Peter; Gerber, Hans; Ferguson, Stephen J; Taylor, William R

2017-01-01

Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability.

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent

Science.gov (United States)

Postolka, Barbara; Schütz, Pascal; Hitz, Marco; Schwilch, Peter; Gerber, Hans

2017-01-01

Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability. PMID:29016647

Study of problems associated with the ultrasonic examination of repeatedly repaired austenitic stainless steel welds

International Nuclear Information System (INIS)

Subbaratnam, R.; Palaniappan, M.; Baskaran, A.; Chandramohan, R.

1994-01-01

In recent years the ultrasonic examination of austenitic stainless steel weldments has gained increased importance as an NDE technique for the volumetric examination in the nuclear power plant construction and other industries. A study has been undertaken to evaluate the effects of multiple repairs on austenitic stainless steel weldments, for the successful ultrasonic examination. The test welds have been subjected to repeated welding cycles and the ultrasonic parameters including the defect characterization have been evaluated for analysis. The paper discusses the approach followed, analysis, results obtained and the recommendations based on the above. 1 fig., 2 tabs

Effectiveness of Fluoroscopic and US - Guided Percutaneous Catheter Drainage for Iliopsoas Abscess through the Anterolateral Transabdominal Approach

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Choi, Ho Cheol; Shin, Tae Beom; Park, Mee Jung; Kim, Ji Eun; Choi, Hye Young; Bae, Kyung Soo; Choi, Dae Seob; Na, Jae Boem; Jeong, Seong Hoon [Gyeongsang National University Hospital, College of Medicine, Jinju (Korea, Republic of)

2011-02-15

We evaluated the effectiveness of performing fluoroscopic and ultrasonography guided percutaneous catheter drainage (PCD) through the anterolateral transabdominal approach for treating iliopsoas abscess. From January 2008 to December 2009, fluoroscopic and US-guided PCD through the anterolateral transabdominal approach was performed on sixteen iliopsoas abscesses of fourteen patients (7 males and 7 females; mean age: 63 years; age range: 30-87 years). Six abscesses were on the right side and ten abscesses were on the left side. The location of the abscesses were the psoas muscle (n=7), the iliacus muscle (n=7) and the iliopsoas muscle (n=2). All the procedures were performed under fluoroscopy and US guidance in the angiography room. The clinical findings before and after the procedure, the duration of catheter insertion and the procedure-related complications were evaluated. 15 out of the 16 iliopsoas abscesses were effectively treated. The duration of catheter insertion was 5- 27 days (mean: 14.6) days. No patient had significant complications during or after drainage. One patient died of uncontrolled diabetes complications and shock on the 9th day after percutaneous catheter drainage. One recurrence was noted 5 months after removal of the catheter. This patient underwent aspiration and antibiotic treatment for this lesion and the patient improved. Fluoroscopic and US-guided PCD for iliopsoas abscess through the anterolateral transabdominal approach is an effective and safe procedure

Fluoroscopically guided percutaneous jejunostomy: outcomes in 25 consecutive patients

International Nuclear Information System (INIS)

Yang, Z.Q.; Shin, J.H.; Song, H.-Y.; Kwon, J.H.; Kim, J.-W.; Kim, K.R.; Kim, J.-H.

2007-01-01

Aim: To assess the feasibility and safety of fluoroscopically guided percutaneous jejunostomy. Material and methods: Between May 1999 and August 2006 percutaneous jejunostomy was attempted in 25 patients. A 5 F vascular catheter (n = 20) or a 7.5 F multifunctional coil catheter (n = 5) was used to insufflate the jejunum. The distended jejunum was punctured using a 17 G needle (n = 19) or a 21 G Chiba needle (n = 6) with the inserted catheter as a target. A 12 or 14 F loop feeding tube was inserted after serial dilations. The technical success, complications, 30-day mortality, and in-dwelling period of the feeding tube placement were evaluated. Results: The technical success rate was 92% (23/25). Technical failures (n = 2) resulted from the inability to insufflate the jejunum secondary to failure to pass the catheter through a malignant stricture at the oesophagojejunostomy site and thus subsequent puncture of the undistended jejunum failed, or failure to introduce the Neff catheter into the jejunum. Pericatheter leakage with pneumoperitoneum was a complication in three patients (12%) and was treated conservatively. The 30-day mortality was 13% (3/23); however, there was no evidence that these deaths were attributed to the procedure. Except for four patients who were lost to follow-up and two failed cases, 15 of the 19 jejunostomy catheters were removed because of patient death (n = 12) or completion of treatment (n = 3), with a mean and median in-dwelling period of 231 and 87 days, respectively. Conclusions: Fluoroscopically guided percutaneous jejunostomy is a feasible procedure with a high technical success and a low complication rate. In addition to a 17 G needle, a 21 G needle can safely be used to puncture the jejunum

Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions

International Nuclear Information System (INIS)

Galster, M.; Adamus, R.; Guhl, C.; Uder, M.

2013-01-01

Purpose: Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. Materials and Methods: A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. Results: The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25 LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. Conclusion: The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. (orig.)

A review of two methods used in the USA to assess HE during fluoroscopic-based radiology

International Nuclear Information System (INIS)

Craig Yoder, R.; Salasky, Mark R.

2016-01-01

Dosemeter results for ∼81 500 people performing fluoroscopic and interventional radiology procedures were examined to identify differences between groups monitored either by using two dosemeters, one placed at the collar above the apron and a second placed under the apron on the torso (EDE1) or by using one single dosemeter placed at the collar above the apron (EDE2). The median annual HE was 0.17 mSv for those monitored using the EDE1 protocol and 0.26 mSv for the group using the EDE2 protocol. The EDE2 method was used most frequently with the EDE1 method preferred for those more highly exposed. Approximately, 22 % of dosemeter results for EDE1 were inconsistent with expected norms based on over and under apron dosemeter relationships. (authors)

High-speed rotary atherectomy under fluoroscopic and angioscopic guidance

International Nuclear Information System (INIS)

Deutsch, L.S.; Ahn, S.S.; Yeatman, L.A.; Marcus, D.R.; Auth, D.P.; Moore, W.S.

1988-01-01

This paper describes thirteen stenotic arteries treated by high-speed rotary abrasive burr atherectomy performed in the operating room under fluoroscopic-angioscopic control by a multidisciplinary team consisting of a vascular surgeon, an interventional radiologist, and an interventional cardiologist. Incrementally sized atherectomy burrs were used in each patient (1.75-4.0 mm in diameter). Rotary artherectomy was successful in 11 of 13 arteries ranging from 1 to 40 cm (median, 5 cm) with stenoses ranging from 50% to 99% (median, 90%), which improved to less than 30% in all 11 successfully atherectomized segments. Two early posttreatment failures (intimal dissection, burr shaft disruption), two posttreatment thromboses (unrelated to atherectomy), and two late failures (restenosis) occurred

Percutaneous interventional forceps removal of radiopaque foreign bodies in soft-tissue under fluoroscopic guidance

International Nuclear Information System (INIS)

Yang Xiujun; Xing Guangfu; Shi Changwen; Li Wei

2011-01-01

Objective: To evaluate the clinical value and limitations of percutaneous interventional forceps retrieval technique under fluoroscopic guidance in removing radiopaque foreign bodies in soft-tissue. Methods: A total of 4 105 consecutive soft-tissue injury patients with radiopaque foreign bodies, encountered in authors' hospital during the period from June 2005 to June 2010, were involved in this study. The diagnosis was confirmed by plain X-ray films in all patients. Additional CT scanning was performed in 1 591 patients, in some of them 3D reconstruction was adopted. With local anesthesia percutaneous interventional forceps retrieval of radiopaque foreign bodies (PIRFB) was carried out under C-arm video-fluoroscopic guidance. Results: Of all patients in this study, 61.34% (2 518/4 105) was treated by PIRFB (study group), and 38.66% (1 587/4 105) was not treated with PIRFB (control group). In study group,the complete and partial curative rate was 95.07% (2 394/2 518) and 4.81% (121/2 518) respectively, and the failure rate was 0.12% (3/2 518). Of 1 587 patients in control group, 25.02% (n=397) left hospital by patient's own reasons and 74.98% (n=1190) was discharged from hospital due to medical or technical reasons. In control group,the foreign objects were close to big vessels in 65.22% (1 035/1 587), large local hematoma was accompanied in 2.90% (46/1 587), associated traumatic pseudoaneurysm was seen in 1.32% (21/1 587) and the foreign objects were glass pieces and the like were found in 5.55% (88/1 587). No serious postoperative complications that required specific therapy, such as bleeding, infection and nerve damage, etc. occurred. CT, especially enhanced CT three-dimensional images, could precisely display the vasculatures nearby the foreign body, which helped make the correct judgment of the removal ability and the operation risk for foreign bodies with interventional procedure. Conclusion: Percutaneous interventional forceps retrieval technique under

Evaluation of methods to produce an image library for automatic patient model localization for dose mapping during fluoroscopically guided procedures

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Kilian-Meneghin, Josh; Xiong, Z.; Rudin, S.; Oines, A.; Bednarek, D. R.

2017-03-01

The purpose of this work is to evaluate methods for producing a library of 2D-radiographic images to be correlated to clinical images obtained during a fluoroscopically-guided procedure for automated patient-model localization. The localization algorithm will be used to improve the accuracy of the skin-dose map superimposed on the 3D patient- model of the real-time Dose-Tracking-System (DTS). For the library, 2D images were generated from CT datasets of the SK-150 anthropomorphic phantom using two methods: Schmid's 3D-visualization tool and Plastimatch's digitally-reconstructed-radiograph (DRR) code. Those images, as well as a standard 2D-radiographic image, were correlated to a 2D-fluoroscopic image of a phantom, which represented the clinical-fluoroscopic image, using the Corr2 function in Matlab. The Corr2 function takes two images and outputs the relative correlation between them, which is fed into the localization algorithm. Higher correlation means better alignment of the 3D patient-model with the patient image. In this instance, it was determined that the localization algorithm will succeed when Corr2 returns a correlation of at least 50%. The 3D-visualization tool images returned 55-80% correlation relative to the fluoroscopic-image, which was comparable to the correlation for the radiograph. The DRR images returned 61-90% correlation, again comparable to the radiograph. Both methods prove to be sufficient for the localization algorithm and can be produced quickly; however, the DRR method produces more accurate grey-levels. Using the DRR code, a library at varying angles can be produced for the localization algorithm.

Initial Experience with Computed Tomography and Fluoroscopically Guided Placement of Push-Type Gastrostomy Tubes Using a Rupture-Free Balloon Catheter

International Nuclear Information System (INIS)

Fujita, Takeshi; Tanabe, Masahiro; Yamatogi, Shigenari; Shimizu, Kensaku; Matsunaga, Naofumi

2011-01-01

The purpose of this study was to evaluate the safety and feasibility of percutaneous radiologic gastrostomy placement of push-type gastrostomy tubes using a rupture-free balloon (RFB) catheter under computed tomography (CT) and fluoroscopic guidance. A total of 35 patients (23 men and 12 women; age range 57–93 years [mean 71.7]) underwent percutaneous CT and fluoroscopically guided gastrostomy placement of a push-type gastrostomy tube using an RFB catheter between April 2005 and July 2008. Technical success, procedure duration, and complications were analyzed. Percutaneous radiologic gastrostomy placement was considered technically successful in all patients. The median procedure time was 39 ± 13 (SD) min (range 24–78). The average follow-up time interval was 103 days (range 7–812). No major complications related to the procedure were encountered. No tubes failed because of blockage, and neither tube dislodgement nor intraperitoneal leakage occurred during the follow-up period. The investigators conclude that percutaneous CT and fluoroscopically guided gastrostomy placement with push-type tubes using an RFB catheter is a safe and effective means of gastric feeding when performed by radiologists.

Leaded eyeglasses substantially reduce radiation exposure of the surgeon's eyes during acquisition of typical fluoroscopic views of the hip and pelvis.

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Burns, Sean; Thornton, Raymond; Dauer, Lawrence T; Quinn, Brian; Miodownik, Daniel; Hak, David J

2013-07-17

Despite recommendations to do so, few orthopaedists wear leaded glasses when performing operative fluoroscopy. Radiation exposure to the ocular lens causes cataracts, and regulatory limits for maximum annual occupational exposure to the eye continue to be revised downward. Using anthropomorphic patient and surgeon phantoms, radiation dose at the surgeon phantom's lens was measured with and without leaded glasses during fluoroscopic acquisition of sixteen common pelvic and hip views. The magnitude of lens dose reduction from leaded glasses was calculated by dividing the unprotected dose by the dose measured behind leaded glasses. On average, the use of leaded glasses reduced radiation to the surgeon phantom's eye by tenfold, a 90% reduction in dose. However, there was widespread variation in the amount of radiation that reached the phantom surgeon's eye among the various radiographic projections we studied. Without leaded glasses, the dose measured at the surgeon's lens varied more than 250-fold among these sixteen different views. In addition to protecting the surgeon's eye from the deleterious effects of radiation, the use of leaded glasses could permit an orthopaedist to perform fluoroscopic views on up to ten times more patients before reaching the annual dose limit of 20 mSv of radiation to the eye recommended by the International Commission on Radiological Protection. Personal safety and adherence to limits of occupational radiation exposure should compel orthopaedists to wear leaded glasses for fluoroscopic procedures if other protective barriers are not in use. Leaded glasses are a powerful tool for reducing the orthopaedic surgeon's lens exposure to radiation during acquisition of common intraoperative fluoroscopic views.

Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

Science.gov (United States)

Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Dore, Antonio; Aringhieri, Giacomo; Caramella, Davide

2018-03-01

To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

Lung tumor tracking in fluoroscopic video based on optical flow

International Nuclear Information System (INIS)

Xu Qianyi; Hamilton, Russell J.; Schowengerdt, Robert A.; Alexander, Brian; Jiang, Steve B.

2008-01-01

Respiratory gating and tumor tracking for dynamic multileaf collimator delivery require accurate and real-time localization of the lung tumor position during treatment. Deriving tumor position from external surrogates such as abdominal surface motion may have large uncertainties due to the intra- and interfraction variations of the correlation between the external surrogates and internal tumor motion. Implanted fiducial markers can be used to track tumors fluoroscopically in real time with sufficient accuracy. However, it may not be a practical procedure when implanting fiducials bronchoscopically. In this work, a method is presented to track the lung tumor mass or relevant anatomic features projected in fluoroscopic images without implanted fiducial markers based on an optical flow algorithm. The algorithm generates the centroid position of the tracked target and ignores shape changes of the tumor mass shadow. The tracking starts with a segmented tumor projection in an initial image frame. Then, the optical flow between this and all incoming frames acquired during treatment delivery is computed as initial estimations of tumor centroid displacements. The tumor contour in the initial frame is transferred to the incoming frames based on the average of the motion vectors, and its positions in the incoming frames are determined by fine-tuning the contour positions using a template matching algorithm with a small search range. The tracking results were validated by comparing with clinician determined contours on each frame. The position difference in 95% of the frames was found to be less than 1.4 pixels (∼0.7 mm) in the best case and 2.8 pixels (∼1.4 mm) in the worst case for the five patients studied.

[Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions].

Science.gov (United States)

Galster, M; Guhl, C; Uder, M; Adamus, R

2013-05-01

Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25°LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. © Georg Thieme Verlag KG Stuttgart · New York.

Fluoroscopically Guided Extraforaminal Cervical Nerve Root Blocks: Analysis of Epidural Flow of the Injectate with Respect to Needle Tip Position

Science.gov (United States)

Shipley, Kyle; Riew, K. Daniel; Gilula, Louis A.

2013-01-01

Study Design Retrospective evaluation of consecutively performed fluoroscopically guided cervical nerve root blocks. Objective To describe the incidence of injectate central epidural flow with respect to needle tip position during fluoroscopically guided extraforaminal cervical nerve root blocks (ECNRBs). Methods Between February 19, 2003 and June 11, 2003, 132 consecutive fluoroscopically guided ECNRBs performed with contrast media in the final injected material (injectate) were reviewed on 95 patients with average of 1.3 injections per patient. Fluoroscopic spot images documenting the procedure were obtained as part of standard quality assurance. An independent observer not directly involved in the procedures retrospectively reviewed the images, and the data were placed into a database. Image review was performed to determine optimal needle tip positioning for injectate epidural flow. Results Central epidural injectate flow was obtained in only 28.9% of injections with the needle tip lateral to midline of the lateral mass (zone 2). 83.8% of injectate went into epidural space when the needle tip was medial to midline of the lateral mass (zone 3). 100% of injectate flowed epidurally when the needle tip was medial to or at the medial cortex of the lateral mass (zone 4). There was no statistically significant difference with regards to central epidural flow and the needle tip position on lateral view. Conclusion To ensure central epidural flow with ECNRBs one must be prepared to pass the needle tip medial to midplane of the lateral mass or to medial cortex of the lateral mass. Approximately 16% of ECNRBs with needle tip medial to midline of the lateral mass did not flow into epidural space. One cannot claim a nerve block is an epidural block unless epidural flow of injectate is observed. PMID:24494176

Fluoroscopic extraction of esophageal foreign body

International Nuclear Information System (INIS)

Chon, Su Bin; Han, Young Min; Chung, Gyung Ho; Sohn, Myung Hee; Kim, Chong Soo; Choi, Ki Chul; Song, Young Ho; Choi, Yeon Wha

1993-01-01

The purpose of this study is to report our 5 year experience with fluoroscopic removal of blunt esophageal foreign body or impacted food in 15 consecutive patients who were referred by endoscopists because they couln't remove it endoscopically. The foreign body or impacted food was a piece of meat, a bean, a badug stone or a beef bone. Thirteen patients had underlying disease (11 of corrosive stricture, 2 of postopertive stricture) but 2 patient did not. We removed the object using one of the following 4 techniques: Basket extraction technique. Foley catheter technique, single balloon technique (dilatation of stenosis for passing the food into the stomach and for the treatment of the stricture as well), double balloon technique (removal of the foregin body by trapping it with two valvuloplasty balloons). Removal was successful in all patients. Esophageal performation occurred in one patient using the sibgle balloon technique, who treated nonoperatively by means of fasting, antibiotics and parenteral alimentation. No procedure related death occurred in these series. In conclusion, fliuroscopic removal of blunt esophageal foreign bodies of impacted food with various techniques is promising alternative to esophagoscopic removal

ESTIMATION OF THE CONVERSION COEFFICIENTS FROM DOSE-AREA PRODUCT TO EFFECTIVE DOSE FOR BARIUM MEAL EXAMINATIONS FOR ADULT PATIENTS

Directory of Open Access Journals (Sweden)

A. V. Vodovatov

2018-01-01

Full Text Available Fluoroscopic examinations of the upper gastro-intestinal tract and, especially, barium meal examinations, are commonly performed in a majority of hospitals. These examinations are associated both with substantial individual patient doses and contribution to the collective dose from medical exposure. Effective dose estimation for this type of examinations is complicated due to: 1 the necessity to simulate the moving X-ray irradiation field; 2 differences in study structure for the individual patients; 3 subjectivity of the operators; and 4 differences in the X-ray equipment. The aim of the current study was to estimate conversion coefficients from dose-area product to effective dose for barium meal examinations for the over couch and under couch exposure conditions. The study was based on data collected in the X-ray unit of the surgical department of the St-Petersburg Mariinsky hospital. A model of patient exposure during barium meal examination was developed based on the collected data on fluoroscopy protocols and adult patient irradiation geometry. Conversion coefficients were calculated using PCXMC 2.0 software. Complete examinations were converted into a set of typical fluoroscopy phases and X-ray images, specified by the examined anatomical region and the projection of patient exposure. Conversion coefficients from dose-area product to effective dose were calculated for each phase of the examination and for the complete examination. The resulting values of the conversion coefficients are comparable with published data. Variations in the absolute values of the conversion coefficients can be explained by differences in clinical protocols, models for the estimation of the effective dose and parameters of barium meal examinations. The proposed approach for estimation of effective dose considers such important features of fluoroscopic examinations as: 1 non-uniform structure of examination, 2 significant movement of the X-ray tube within a single

SU-G-JeP1-11: Feasibility Study of Markerless Tracking Using Dual Energy Fluoroscopic Images for Real-Time Tumor-Tracking Radiotherapy System

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Shiinoki, T; Shibuya, K [Yamaguchi University, Ube, Yamaguchi (Japan); Sawada, A [Kyoto college of medical science, Nantan, Kyoto (Japan); Uehara, T; Yuasa, Y; Koike, M; Kawamura, S [Yamaguchi University Hospital, Ube, Yamaguchi (Japan)

2016-06-15

Purpose: The new real-time tumor-tracking radiotherapy (RTRT) system was installed in our institution. This system consists of two x-ray tubes and color image intensifiers (I.I.s). The fiducial marker which was implanted near the tumor was tracked using color fluoroscopic images. However, the implantation of the fiducial marker is very invasive. Color fluoroscopic images enable to increase the recognition of the tumor. However, these images were not suitable to track the tumor without fiducial marker. The purpose of this study was to investigate the feasibility of markerless tracking using dual energy colored fluoroscopic images for real-time tumor-tracking radiotherapy system. Methods: The colored fluoroscopic images of static and moving phantom that had the simulated tumor (30 mm diameter sphere) were experimentally acquired using the RTRT system. The programmable respiratory motion phantom was driven using the sinusoidal pattern in cranio-caudal direction (Amplitude: 20 mm, Time: 4 s). The x-ray condition was set to 55 kV, 50 mA and 105 kV, 50 mA for low energy and high energy, respectively. Dual energy images were calculated based on the weighted logarithmic subtraction of high and low energy images of RGB images. The usefulness of dual energy imaging for real-time tracking with an automated template image matching algorithm was investigated. Results: Our proposed dual energy subtraction improve the contrast between tumor and background to suppress the bone structure. For static phantom, our results showed that high tracking accuracy using dual energy subtraction images. For moving phantom, our results showed that good tracking accuracy using dual energy subtraction images. However, tracking accuracy was dependent on tumor position, tumor size and x-ray conditions. Conclusion: We indicated that feasibility of markerless tracking using dual energy fluoroscopic images for real-time tumor-tracking radiotherapy system. Furthermore, it is needed to investigate the

Reduction of radiation exposure while maintaining high-quality fluoroscopic images during interventional cardiology using novel x-ray tube technology with extra beam filtering.

Science.gov (United States)

den Boer, A; de Feyter, P J; Hummel, W A; Keane, D; Roelandt, J R

1994-06-01

Radiographic technology plays an integral role in interventional cardiology. The number of interventions continues to increase, and the associated radiation exposure to patients and personnel is of major concern. This study was undertaken to determine whether a newly developed x-ray tube deploying grid-switched pulsed fluoroscopy and extra beam filtering can achieve a reduction in radiation exposure while maintaining fluoroscopic images of high quality. Three fluoroscopic techniques were compared: continuous fluoroscopy, pulsed fluoroscopy, and a newly developed high-output pulsed fluoroscopy with extra filtering. To ascertain differences in the quality of images and to determine differences in patient entrance and investigator radiation exposure, the radiated volume curve was measured to determine the required high voltage levels (kVpeak) for different object sizes for each fluoroscopic mode. The fluoroscopic data of 124 patient procedures were combined. The data were analyzed for radiographic projections, image intensifier field size, and x-ray tube kilovoltage levels (kVpeak). On the basis of this analysis, a reference procedure was constructed. The reference procedure was tested on a phantom or dummy patient by all three fluoroscopic modes. The phantom was so designed that the kilovoltage requirements for each projection were comparable to those needed for the average patient. Radiation exposure of the operator and patient was measured during each mode. The patient entrance dose was measured in air, and the operator dose was measured by 18 dosimeters on a dummy operator. Pulsed compared with continuous fluoroscopy could be performed with improved image quality at lower kilovoltages. The patient entrance dose was reduced by 21% and the operator dose by 54%. High-output pulsed fluoroscopy with extra beam filtering compared with continuous fluoroscopy improved the image quality, lowered the kilovoltage requirements, and reduced the patient entrance dose by 55% and

Selecting appropriate gastroenteric contrast media for diagnostic fluoroscopic imaging in infants and children: a practical approach.

Science.gov (United States)

Callahan, Michael J; Talmadge, Jennifer M; MacDougall, Robert D; Kleinman, Patricia L; Taylor, George A; Buonomo, Carlo

2017-04-01

In our experience, questions about the appropriate use of enteric contrast media for pediatric fluoroscopic studies are common. The purpose of this article is to provide a comprehensive review of enteric contrast media used for pediatric fluoroscopy, highlighting the routine use of these media at a large tertiary care pediatric teaching hospital.

Eye lens dosimetry for fluoroscopically guided clinical procedures: practical approaches to protection and dose monitoring

International Nuclear Information System (INIS)

Martin, Colin J.

2016-01-01

Doses to the eye lenses of clinicians undertaking fluoroscopically guided procedures can exceed the dose annual limit of 20 mSv, so optimisation of radiation protection is essential. Ceiling-suspended shields and disposable radiation absorbing pads can reduce eye dose by factors of 2-7. Lead glasses that shield against exposures from the side can lower doses by 2.5-4.5 times. Training in effective use of protective devices is an essential element in achieving good protection and acceptable eye doses. Effective methods for dose monitoring are required to identify protection issues. Dosemeters worn adjacent to the eye provide the better option for interventional clinicians, but an unprotected dosemeter worn at the neck will give an indication of eye dose that is adequate for most interventional staff. Potential requirements for protective devices and dose monitoring can be determined from risk assessments using generic values for dose linked to examination workload. (author)

Stochastic risk estimation from medical x-ray diagnostic examinations, 2. Risk estimates of individuals from x-ray diagnosis

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Maruyama, T; Noda, Y; Iwai, K; Tateno, Y [National Inst. of Radiological Sciences, Chiba (Japan); Nishizawa, K

1981-01-01

The risks of genetic, leukemia and malignant diseases from medical X-ray diagnostic examinations were estimated using the frequency of radiographic and fluoroscopic exposures per diagnostic examination, child expectancy, leukemia and malignancy significant factors, and using a weighting factor determined on the basis of data concerning the cancer mortality among atomic bomb survivors in Nagasaki and of a recommendation of International Commission of Radiological Protection. The organ or tissue doses with respect to the stochastic risks were determined with ionization chambers and thermoluminescent dosimeters placed at the positions of the organs or tissues in a RANDO woman phantom which was exposed to diagnostic X-rays according to technical factors of typical radiographic and fluoroscopic examinations obtained from a nationwide survey. The resultant risks by age-group and type of radiographic and fluoroscopic examination are tabulated in terms of risk level of 10/sup -6/. In general, the total risk defined as the sum of genetic, leukemia and malignant risks was a high value for the X-ray diagnosis of digestive organs involving barium meal and barium enema. For example, the total risk for young age-group was 100 to 200 x 10/sup -6/ for the X-ray diagnosis of digestive organs. The total risk from the chest radiography was lower value as compared with the risk from the X-ray diagnosis of other organs or tissues. On the contrary, the risk from the chest tomography was comparable to the risk from the diagnosis of digestive organs. The total risk decreased with increasing of age for every X-ray diagnostic examination.

SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

International Nuclear Information System (INIS)

Feng, C; Thai, L; Wagner, L; Ozus, B

2016-01-01

Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm"3 ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

Energy Technology Data Exchange (ETDEWEB)

Feng, C; Thai, L; Wagner, L [The University of Texas Health Science Center at Houston, Houston, TX (United States); Ozus, B [CHI St Luke’s Health, Baylor St Luke’s Medical Center, Houston, TX (United States)

2016-06-15

Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm{sup 3} ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

Scattered radiation dose to radiologist's cornea, thyroid and gonads while performing some x-ray fluoroscopic investigations

International Nuclear Information System (INIS)

Chougle, Arun

1993-01-01

The mankind has been immensely benefited from discovery of X-ray and it has found wide spread application in diagnosis and treatment. Radiation is harmful and can produce somatic and genetic effects in the exposed person. International Commission on Radiation Protection (ICRP) has recommended a system of dose limitation based on principle of ALARA. All the efforts should be made to keep the radiation dose to the radiation worker as low as possible. Fluoroscopy gives maximum dose to the patient and staff and hence we have attempted to quantify the scattered radiation dose to the cornea, thyroid and gonads of the radiologist performing fluoroscopic examinations such as barium meal, barium swallow, barium enema, myelography, histerosalpingography and fracture reduction. Thermoluminescence dosimetry (TLD) method using CaSO 4 :Dy TLD disc was employed for these measurements. Use of lead apron has reduced the dose to radiologist's gonad. (author). 3 refs., 4 tabs

Percutaneous Transhepatic Drainage of Inaccessible Abdominal Abscesses Following Abdominal Surgery Under Real-Time CT-Fluoroscopic Guidance

International Nuclear Information System (INIS)

Yamakado, Koichiro; Takaki, Haruyuki; Nakatsuka, Atsuhiro; Kashima, Masataka; Uraki, Junji; Yamanaka, Takashi; Takeda, Kan

2010-01-01

This study evaluated the safety, feasibility, and clinical utility of transhepatic drainage of inaccessible abdominal abscesses retrospectively under real-time computed tomographic (CT) guidance. For abdominal abscesses, 12 consecutive patients received percutaneous transhepatic drainage. Abscesses were considered inaccessible using the usual access route because they were surrounded by the liver and other organs. The maximum diameters of abscesses were 4.6-9.5 cm (mean, 6.7 ± 1.4 cm). An 8-Fr catheter was advanced into the abscess cavity through the liver parenchyma using real-time CT fluoroscopic guidance. Safety, feasibility, procedure time, and clinical utility were evaluated. Drainage catheters were placed with no complications in abscess cavities through the liver parenchyma in all patients. The mean procedure time was 18.8 ± 9.2 min (range, 12-41 min). All abscesses were drained. They shrank immediately after catheter placement. In conclusions, this transhepatic approach under real-time CT fluoroscopic guidance is a safe, feasible, and useful technique for use of drainage of inaccessible abdominal abscesses.

Under digital fluoroscopic guidance multiple-point injection with absolute alcohol and pinyangmycin for the treatment of superficial venous malformations

International Nuclear Information System (INIS)

Yang Ming; Xiao Gang; Peng Youlin

2010-01-01

Objective: to investigate the therapeutic efficacy of multiple-point injection with absolute alcohol and pinyangmycin under digital fluoroscopic guidance for superficial venous malformations. Methods: By using a disposal venous transfusion needle the superficial venous malformation was punctured and then contrast media lohexol was injected in to visualize the tumor body, which was followed by the injection of ethanol and pinyangmycin when the needle was confirmed in the correct position. The procedure was successfully performed in 31 patients. The clinical results were observed and analyzed. Results: After one treatment complete cure was achieved in 21 cases and marked effect was obtained in 8 cases, with a total effectiveness of 93.5%. Conclusion: Multiple-point injection with ethanol and pinyangmycin under digital fluoroscopic guidance is an effective and safe technique for the treatment of superficial venous malformations, especially for the lesions that are deeply located and ill-defined. (authors)

The ALARA (as low as reasonably achievable) concept in pediatric interventional and fluoroscopic imaging: striving to keep radiation doses as low as possible during fluoroscopy of pediatric patients - a white paper executive summary

International Nuclear Information System (INIS)

Strauss, Keith J.; Kaste, Sue C.

2006-01-01

ALARA represents a practice mandate adhering to the principle of keeping radiation doses to patients and personnel As Low As Reasonably Achievable. This concept is strongly endorsed by the Society for Pediatric Radiology, particularly in the use of procedures and modalities involving higher radiation doses such as CT and fluoroscopic examinations of pediatric patients. There is no doubt that medical imaging, which has undergone tremendous technological advances in recent decades, is integral to patient care. However, these technological advances generally precede the knowledge of end-users concerning the optimal use and correct operation of the resulting imaging equipment, and such knowledge is essential to minimizing potential risks to the patients. Current imaging methods must be optimized for radiation dose reduction in pediatric patients who might be as much as ten times more radiosensitive than adults. Unlike straightforward radiographic examinations, radiation dose to the patient during fluoroscopy is dependent on the operator's training, experience with the fluoroscope, and efficiency in completing a diagnostic study. The range of pediatric radiation doses from fluoroscopy is wide because this examination is performed not only by pediatric radiologists but also by general radiologists who occasionally care for children, interventional cardiologists, gastroenterologists, urologists and others. Thus, a venue where multidisciplinary interaction by this variety of operators can occur serves to improve pediatric patient care

Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts in the treatment of acute malignant colorectal obstruction.

Science.gov (United States)

Kim, Honsoul; Kim, Seung Hyoung; Choi, Sun Young; Lee, Kwang-Hun; Won, Jong Yoon; Lee, Do Yun; Lee, Jong Tae

2008-12-01

To evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for acute malignant colorectal obstruction. Radiologic images and clinical reports of 42 patients (22 men, 20 women; age range, 28-93 years; median age, 65.5 years) who underwent fluoroscopically guided colorectal stent insertion without endoscopic assistance for acute malignant obstruction were reviewed retrospectively. Eighteen patients received bare stents as a bridge to surgery. Twenty-four patients received 27 insertions of either a bare stent (n = 15) or a stent-graft (n = 12) for palliation. The obstruction was located in the rectum (n = 8), sigmoid (n = 17), descending colon (n = 8), splenic flexure (n = 3), and transverse colon (n = 6). Clinical success, defined as more than 50% dilatation of the stent with subsequent symptomatic improvement, was achieved in 41 of the 42 patients (98%). No major procedure-related complications occurred. Minor complications occurred in eight of the 45 procedures (18%). No perioperative mortalities occurred within 1 month after surgery. In the palliative group, the median stent patency was 62 days (range, 0-1,014 days). There was no statistically significant difference in stent patency between the bare stents (range, 0-855 days; median, 68 days) and stent-grafts (range, 1-1,014 days; median, 81 days). Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for the relief of acute malignant colorectal obstruction was technically feasible without endoscopic assistance-even in lesions proximal to the splenic flexure and transverse colon-and clinically effective in both bridge to surgery and palliative management.

Stent placement under fluoroscopic monitoring and endoscopic direct vision for the treatment of malignant gastroduodenal obstruction: a report of 47 cases

International Nuclear Information System (INIS)

Zhang Baoyang; Li Weiping; Jiang Haosheng; Liu Shiyi; Hu Yi

2009-01-01

Objective: To discuss the operational technique and clinical effect of metallic stent placement in treating malignant gastroduodenal obstruction. Methods: Metallic stent placement under fluoroscopic monitoring and endoscopic direct vision was performed in 47 patients with malignant gastroduodenal obstruction. A total of 54 metallic stents was used. Results: The procedure was successfully completed in all 47 patients. During the follow-up period, all the patients could take liquid or ordinary diet and were markedly relived of vomiting. The living quality was much improved and no serious complications occurred. Conclusion: Under fluoroscopic monitoring and endoscopic direct vision, stent placement is a safe, effective, technically-simple and time-saving procedure for the treatment of malignant gastroduodenal obstruction with less sufferings to the patient. Therefore, it is definitely worth popularizing this technique in clinical practice. (authors)

Robust fluoroscopic tracking of fiducial markers: exploiting the spatial constraints

International Nuclear Information System (INIS)

Li Rui; Sharp, Gregory

2013-01-01

Two new fluoroscopic fiducial tracking methods that exploit the spatial relationship among the multiple implanted fiducial to achieve fast, accurate and robust tracking are proposed in this paper. The spatial relationship between multiple implanted markers are modeled as Gaussian distributions of their pairwise distances over time. The means and standard deviations of these distances are learned from training sequences, and pairwise distances that deviate from these learned distributions are assigned a low spatial matching score. The spatial constraints are incorporated in two different algorithms: a stochastic tracking method and a detection based method. In the stochastic method, hypotheses of the ‘true’ fiducial position are sampled from a pre-trained respiration motion model. Each hypothesis is assigned an importance value based on image matching score and spatial matching score. Learning the parameters of the motion model is needed in addition to learning the distribution parameters of the pairwise distances in the proposed stochastic tracking approach. In the detection based method, a set of possible marker locations are identified by using a template matching based fiducial detector. The best location is obtained by optimizing the image matching score and spatial matching score through non-serial dynamic programming. In this detection based approach, there is no need to learn the respiration motion model. The two proposed algorithms are compared with a recent work using a multiple hypothesis tracking (MHT) algorithm which is denoted by MHT, Tang et al (2007 Phys. Med. Biol. 52 4081–98). Phantom experiments were performed using fluoroscopic videos captured with known motion relative to an anthropomorphic phantom. The patient experiments were performed using a retrospective study of 16 fluoroscopic videos of liver cancer patients with implanted fiducials. For the motion phantom data sets, the detection based approach has the smallest tracking error (�

Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis; Vergleich von konventioneller Wirbelsaeulenganzaufnahme und fluoroskopischer Scan-Methode bei jungen Patienten mit idiopathischer Skoliose

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Schaefer, J.; Kottke, R.; Claussen, C. [Abt. fuer Radiologische Diagnostik, Universitaetsklinikum Tuebingen (Germany); Kluba, T.; Niemeyer, T.; Hahnfeldt, T. [Klinik und Poliklinik fuer Orthopaedie, Universitaetsklinikum Tuebingen (Germany); Vonthein, R. [Inst. fuer Medizinische Biometrie, Universitaetsklinikum Tuebingen (Germany); Kamm, K.F. [Philips Medizin Systeme GmbH, Hamburg (Germany)

2005-08-01

Purpose: evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. Material and methods: twenty-one consecutive patients (aged 10-27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software easy spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. Results: the mean DAP values for conventional imaging was 94.9 cGy x cm{sup 2} and for fluoroscopy 7.8 cGy x cm{sup 2}, respectively. A significant dose reduction of 91.8% (CI 91% to 95%) was calculated. The average absolute angle difference between the observers was found to be 2.7 for conventional imaging and 2.4 for the fluoroscopic method. Interobserver standard deviation of 2.9 was lower than the 5.3 for conventional images. Image quality was better in the conventional images. Conclusion: using the scanning method, we could achieve a mean reduction of the radiation dose of 92%, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy. (orig.)

Characterization of a high-elbow, fluoroscopic electronic portal imaging device for portal dosimetry

International Nuclear Information System (INIS)

Boer, J.C.J. de; Visser, A.G.

2000-01-01

The application of a newly developed fluoroscopic (CCD-camera based) electronic portal imaging device (EPID) in portal dosimetry is investigated. A description of the EPID response to dose is presented in terms of stability, linearity and optical cross-talk inside the mechanical structure. The EPID has a relatively large distance (41 cm on-axis) between the fluorescent screen and the mirror (high-elbow), which results in cross-talk with properties quite different from that of the low-elbow fluoroscopic EPIDs that have been studied in the literature. In contrast with low-elbow systems, the maximum cross-talk is observed for points of the fluorescent screen that have the largest distance to the mirror, which is explained from the geometry of the system. An algorithm to convert the images of the EPID into portal dose images (PDIs) is presented. The correction applied for cross-talk is a position-dependent additive operation on the EPID image pixel values, with a magnitude that depends on a calculated effective field width. Deconvolution with a point spread function, as applied for low-elbow systems, is not required. For a 25 MV beam, EPID PDIs and ionization chamber measurements in the EPID detector plane were obtained behind an anthropomorphic phantom and a homogeneous absorber for various field shapes. The difference in absolute dose between the EPID and ionization chamber measurements, averaged over the four test fields presented in this paper, was 0.1±0.5% (1 SD) over the entire irradiation field, with no deviation larger than 2%. (author)

Accurate 3D kinematic measurement of temporomandibular joint using X-ray fluoroscopic images

Science.gov (United States)

Yamazaki, Takaharu; Matsumoto, Akiko; Sugamoto, Kazuomi; Matsumoto, Ken; Kakimoto, Naoya; Yura, Yoshiaki

2014-04-01

Accurate measurement and analysis of 3D kinematics of temporomandibular joint (TMJ) is very important for assisting clinical diagnosis and treatment of prosthodontics and orthodontics, and oral surgery. This study presents a new 3D kinematic measurement technique of the TMJ using X-ray fluoroscopic images, which can easily obtain the TMJ kinematic data in natural motion. In vivo kinematics of the TMJ (maxilla and mandibular bone) is determined using a feature-based 2D/3D registration, which uses beads silhouette on fluoroscopic images and 3D surface bone models with beads. The 3D surface models of maxilla and mandibular bone with beads were created from CT scans data of the subject using the mouthpiece with the seven strategically placed beads. In order to validate the accuracy of pose estimation for the maxilla and mandibular bone, computer simulation test was performed using five patterns of synthetic tantalum beads silhouette images. In the clinical applications, dynamic movement during jaw opening and closing was conducted, and the relative pose of the mandibular bone with respect to the maxilla bone was determined. The results of computer simulation test showed that the root mean square errors were sufficiently smaller than 1.0 mm and 1.0 degree. In the results of clinical application, during jaw opening from 0.0 to 36.8 degree of rotation, mandibular condyle exhibited 19.8 mm of anterior sliding relative to maxillary articular fossa, and these measurement values were clinically similar to the previous reports. Consequently, present technique was thought to be suitable for the 3D TMJ kinematic analysis.

Fluoroscopically guided closed reduction and internal fixation of fractures of the lateral portion of the humeral condyle: prospective clinical study of the technique and results in ten dogs.

Science.gov (United States)

Cook, J L; Tomlinson, J L; Reed, A L

1999-01-01

To report a technique for fluoroscopically guided closed reduction with internal fixation of fractures of the lateral portion of the humeral condyle (FLHC) and determine the long-term results in 10 clinical cases. Prospective clinical case study. Ten dogs with 11 fractures. Fractures of the lateral portion of the humeral condyle were stabilized with transcondylar screws and Kirschner wires. Closed reduction and implant placement were achieved using intraoperative fluoroscopic guidance. After fracture repair, postoperative radiographs were evaluated for articular alignment and implant placement. Dogs were evaluated after surgery by means of lameness scores, elbow range of motion (ROM), radiographic assessment, and owner evaluation of function. Postoperative reduction was considered anatomic in 6 fractures with all other fractures having ROM values between affected and unaffected elbows. All of the dogs in this study regained 90-100% of full function, based on owner assessment. Fluoroscopic guidance for closed reduction and internal fixation of FLHC in dogs is an effective technique.

WE-G-207-06: 3D Fluoroscopic Image Generation From Patient-Specific 4DCBCT-Based Motion Models Derived From Physical Phantom and Clinical Patient Images

International Nuclear Information System (INIS)

Dhou, S; Cai, W; Hurwitz, M; Rottmann, J; Myronakis, M; Cifter, F; Berbeco, R; Lewis, J; Williams, C; Mishra, P; Ionascu, D

2015-01-01

Purpose: Respiratory-correlated cone-beam CT (4DCBCT) images acquired immediately prior to treatment have the potential to represent patient motion patterns and anatomy during treatment, including both intra- and inter-fractional changes. We develop a method to generate patient-specific motion models based on 4DCBCT images acquired with existing clinical equipment and used to generate time varying volumetric images (3D fluoroscopic images) representing motion during treatment delivery. Methods: Motion models are derived by deformably registering each 4DCBCT phase to a reference phase, and performing principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated by optimizing the resulting PCA coefficients iteratively through comparison of the cone-beam projections simulating kV treatment imaging and digitally reconstructed radiographs generated from the motion model. Patient and physical phantom datasets are used to evaluate the method in terms of tumor localization error compared to manually defined ground truth positions. Results: 4DCBCT-based motion models were derived and used to generate 3D fluoroscopic images at treatment time. For the patient datasets, the average tumor localization error and the 95th percentile were 1.57 and 3.13 respectively in subsets of four patient datasets. For the physical phantom datasets, the average tumor localization error and the 95th percentile were 1.14 and 2.78 respectively in two datasets. 4DCBCT motion models are shown to perform well in the context of generating 3D fluoroscopic images due to their ability to reproduce anatomical changes at treatment time. Conclusion: This study showed the feasibility of deriving 4DCBCT-based motion models and using them to generate 3D fluoroscopic images at treatment time in real clinical settings. 4DCBCT-based motion models were found to account for the 3D non-rigid motion of the patient anatomy during treatment and have the potential

Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor

International Nuclear Information System (INIS)

Shirato, Hiroki; Shimizu, Shinichi; Kitamura, Kei; Nishioka, Takeshi; Kagei, Kenji; Hashimoto, Seiko; Aoyama, Hidefumi; Kunieda, Tatsuya; Shinohara, Nobuo; Dosaka-Akita, Hirotoshi; Miyasaka, Kazuo

2000-01-01

Purpose: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice. Methods and Materials: We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second. The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter. Results: The coordinates of the marker were detected with an accuracy of ± 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a 'tight' planning target volume (PTV) margin. They were surviving without relapse or complications with a median follow-up of 6 months. Conclusion: Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors

Efficacy of repeated 5-fluorouracil needling for failing and failed filtering surgeries based on simple gonioscopic examination

Directory of Open Access Journals (Sweden)

Rashad MA

2012-12-01

Full Text Available Mohammad A RashadOphthalmology Department, Faculty of Medicine, Ain Shams University, Cairo, EgyptPurpose: To evaluate the success rate of a modified bleb needling technique in eyes with previous glaucoma surgery that had elevated intraocular pressure.Methods: A retrospective study of 24 eyes of 24 patients that underwent repeated bleb needling performed for failing and failed blebs on slit lamp with 5-fluorouracil (5-FU injections on demand. This was performed after gonioscopic examination to define levels of filtration block.Results: There was significant reduction of mean IOP from 36.91 mmHg to 14.73 mmHg at the final follow-up (P < 0.001. The overall success rate was 92%.Conclusion: Repeated needling with adjunctive 5-FU proved a highly effective, safe alternative to revive filtration surgery rather than another medication or surgery.Keywords: bleb, failure, 5-FU, needling, gonioscopy

The effect of barium temperature on esophageal and castric motility in dogs: a fluoroscopic study

International Nuclear Information System (INIS)

Eville, P.; Ackerman, N.

1984-01-01

The influence of barium temperature on canine esophageal transit time and gastric motility were studied fluoroscopically. Micropulverized barium sulfate (30% wt/vol) at 35°F, 70°F, and 100°F was given orally to each of five dogs with a minimum of two hours between each temperature. Esophageal transit times ranged from 4 to 9.67 seconds, and gastric contractions average four per minute. Barium temperature had no significant effect on either esophageal transit time or gastric motility

SU-E-J-01: 3D Fluoroscopic Image Estimation From Patient-Specific 4DCBCT-Based Motion Models

International Nuclear Information System (INIS)

Dhou, S; Hurwitz, M; Lewis, J; Mishra, P

2014-01-01

Purpose: 3D motion modeling derived from 4DCT images, taken days or weeks before treatment, cannot reliably represent patient anatomy on the day of treatment. We develop a method to generate motion models based on 4DCBCT acquired at the time of treatment, and apply the model to estimate 3D time-varying images (referred to as 3D fluoroscopic images). Methods: Motion models are derived through deformable registration between each 4DCBCT phase, and principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated based on cone-beam projections simulating kV treatment imaging. PCA coefficients are optimized iteratively through comparison of these cone-beam projections and projections estimated based on the motion model. Digital phantoms reproducing ten patient motion trajectories, and a physical phantom with regular and irregular motion derived from measured patient trajectories, are used to evaluate the method in terms of tumor localization, and the global voxel intensity difference compared to ground truth. Results: Experiments included: 1) assuming no anatomic or positioning changes between 4DCT and treatment time; and 2) simulating positioning and tumor baseline shifts at the time of treatment compared to 4DCT acquisition. 4DCBCT were reconstructed from the anatomy as seen at treatment time. In case 1) the tumor localization error and the intensity differences in ten patient were smaller using 4DCT-based motion model, possible due to superior image quality. In case 2) the tumor localization error and intensity differences were 2.85 and 0.15 respectively, using 4DCT-based motion models, and 1.17 and 0.10 using 4DCBCT-based models. 4DCBCT performed better due to its ability to reproduce daily anatomical changes. Conclusion: The study showed an advantage of 4DCBCT-based motion models in the context of 3D fluoroscopic images estimation. Positioning and tumor baseline shift uncertainties were mitigated by the 4DCBCT

Estimation of lung shunt fraction from simultaneous fluoroscopic and nuclear images

Science.gov (United States)

van der Velden, Sandra; Bastiaannet, Remco; Braat, Arthur J. A. T.; Lam, Marnix G. E. H.; Viergever, Max A.; de Jong, Hugo W. A. M.

2017-11-01

Radioembolisation with yttrium-90 (90Y) is increasingly used as a treatment of unresectable liver malignancies. For safety, a scout dose of technetium-99m macroaggregated albumin (99mTc-MAA) is used prior to the delivery of the therapeutic activity to mimic the deposition of 90Y. One-day procedures are currently limited by the lack of nuclear images in the intervention room. To cope with this limitation, an interventional simultaneous fluoroscopic and nuclear imaging device is currently being developed. The purpose of this simulation study was to evaluate the accuracy of estimating the lung shunt fraction (LSF) of the scout dose in the intervention room with this device and compare it against current clinical methods. Methods: A male and female XCAT phantom, both with two respiratory profiles, were used to simulate various LSFs resulting from a scout dose of 150 MBq 99mTc-MAA. Hybrid images were Monte Carlo simulated for breath-hold (5 s) and dynamic breathing (10 frames of 0.5 s) acquisitions. Nuclear images were corrected for attenuation with the fluoroscopic image and for organ overlap effects using a pre-treatment CT-scan. For comparison purposes, planar scintigraphy and mobile gamma camera images (both 300 s acquisition time) were simulated. Estimated LSFs were evaluated for all methods and compared to the phantom ground truth. Results: In the clinically relevant range of 10-20% LSF, hybrid imaging overestimated LSF with approximately 2 percentage points (pp) and 3 pp for the normal and irregular breathing phantoms, respectively. After organ overlap correction, LSF was estimated with a more constant error. Errors in planar scintigraphy and mobile gamma camera imaging were more dependent on LSF, body shape and breathing profile. Conclusion: LSF can be estimated with a constant minor error with a hybrid imaging device. Estimated LSF is highly dependent on true LSF, body shape and breathing pattern when estimated with current clinical methods. The hybrid

Brain pathology after mild traumatic brain injury: an exploratory study by repeated magnetic resonance examination.

Science.gov (United States)

Lannsjö, Marianne; Raininko, Raili; Bustamante, Mariana; von Seth, Charlotta; Borg, Jörgen

2013-09-01

To explore brain pathology after mild traumatic brain injury by repeated magnetic resonance examination. A prospective follow-up study. Nineteen patients with mild traumatic brain injury presenting with Glasgow Coma Scale (GCS) 14-15. The patients were examined on day 2 or 3 and 3-7 months after the injury. The magnetic resonance protocol comprised conventional T1- and T2-weighted sequences including fluid attenuated inversion recovery (FLAIR), two susceptibility-weighted sequences to reveal haemorrhages, and diffusion-weighted sequences. Computer-aided volume comparison was performed. Clinical outcome was assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Hospital Anxiety and Depression Scale (HADS) and Glasgow Outcome Scale Extended (GOSE). At follow-up, 7 patients (37%) reported ≥  3 symptoms in RPQ, 5 reported some anxiety and 1 reported mild depression. Fifteen patients reported upper level of good recovery and 4 patients lower level of good recovery (GOSE 8 and 7, respectively). Magnetic resonance pathology was found in 1 patient at the first examination, but 4 patients (21%) showed volume loss at the second examination, at which 3 of them reported GOSE scores of 8. Loss of brain volume, demonstrated by computer-aided magnetic resonance imaging volumetry, may be a feasible marker of brain pathology after mild traumatic brain injury.

Fluoroscopic study of the normal gastrointestinal motility and measurements in the Hispaniolan Amazon parrot (Amazona ventralis).

Science.gov (United States)

Beaufrère, Hugues; Nevarez, Javier; Taylor, W Michael; Jankowski, Gwendolyn; Rademacher, Nathalie; Gaschen, Lorrie; Pariaut, Romain; Tully, Thomas N

2010-01-01

Contrast fluoroscopy is a valuable tool to examine avian gastrointestinal motility. However, the lack of a standardized examination protocol and reference ranges prevents the objective interpretation of motility disorders and other gastrointestinal abnormalities. Our goals were to evaluate gastrointestinal motility in 20 Hispaniolan Amazon parrots (Amazona ventralis) by contrast fluoroscopy. Each parrot was crop-fed an equal part mixture of barium sulfate and hand-feeding formula and placed in a cardboard box for fluoroscopy. Over a 3-h period, 1.5 minute segments of lateral and ventrodorsal fluoroscopy were recorded every 30 min. The gastric cycle and patterns of intestinal motility were described. The frequency of crop contractions, esophageal boluses, and gastric cycles were determined in lateral and ventrodorsal views. A range of 3.4-6.6 gastric cycles/min was noted on the lateral view and 3.0-6.6 gastric cycles/min on the ventrodorsal view. Circular measurements of the proventriculus diameter, ventriculus width, and length were obtained using the midshaft femoral diameter as a standard reference unit. The upper limits of the reference ranges were 3.6 and 4.7 femoral units for the proventriculus diameter in the lateral and ventrodorsal view, respectively. Two consecutive measurements were obtained and the measurement technique was found to have high reproducibility. In this study, we established a standardized protocol for contrast fluoroscopic examination of the gastrointestinal tract and a reliable measurement method of the proventriculus and ventriculus using femoral units in the Hispaniolan Amazon parrot.

Identification of arteries and veins in cerebral angiography fluoroscopic images

Science.gov (United States)

Andra Tache, Irina

2017-11-01

In the present study a new method for pixels tagging into arteries and veins classes from temporal cerebral angiography is presented. This need comes from the neurosurgeon who is evaluating the fluoroscopic angiography and the magnetic resonance images from the brain in order to locate the fistula of the patients who suffer from arterio-venous malformation. The method includes the elimination of the background pixels from a previous segmentation and the generation of the time intensity curves for each remaining pixel. The later undergo signal processing in order to extract the characteristic parameters needed for applying the k-means clustering algorithm. Some of the parameters are: the phase and the maximum amplitude extracted from the Fourier transform, the standard deviation and the mean value. The tagged classes are represented into images which then are re-classified by an expert into artery and vein pixels.

Closed reduction and fluoroscopic assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats

OpenAIRE

Boekhout-Ta, Christina L; Kim, Stanley E; Corss, Alan R; Pozzi, Antonio; Evans, Richard

2017-01-01

OBJECTIVE: To report complications and clinical outcome of dogs and cats that underwent fluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned dogs (n = 37) and cats (n = 4). MATERIALS AND METHODS: Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated. Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harris classi...

Fluoroscopic gating without implanted fiducial markers for lung cancer radiotherapy based on support vector machines

International Nuclear Information System (INIS)

Cui Ying; Dy, Jennifer G; Alexander, Brian; Jiang, Steve B

2008-01-01

Various problems with the current state-of-the-art techniques for gated radiotherapy have prevented this new treatment modality from being widely implemented in clinical routine. These problems are caused mainly by applying various external respiratory surrogates. There might be large uncertainties in deriving the tumor position from external respiratory surrogates. While tracking implanted fiducial markers has sufficient accuracy, this procedure may not be widely accepted due to the risk of pneumothorax. Previously, we have developed a technique to generate gating signals from fluoroscopic images without implanted fiducial markers using template matching methods (Berbeco et al 2005 Phys. Med. Biol. 50 4481-90, Cui et al 2007b Phys. Med. Biol. 52 741-55). In this note, our main contribution is to provide a totally different new view of the gating problem by recasting it as a classification problem. Then, we solve this classification problem by a well-studied powerful classification method called a support vector machine (SVM). Note that the goal of an automated gating tool is to decide when to turn the beam ON or OFF. We treat ON and OFF as the two classes in our classification problem. We create our labeled training data during the patient setup session by utilizing the reference gating signal, manually determined by a radiation oncologist. We then pre-process these labeled training images and build our SVM prediction model. During treatment delivery, fluoroscopic images are continuously acquired, pre-processed and sent as an input to the SVM. Finally, our SVM model will output the predicted labels as gating signals. We test the proposed technique on five sequences of fluoroscopic images from five lung cancer patients against the reference gating signal as ground truth. We compare the performance of the SVM to our previous template matching method (Cui et al 2007b Phys. Med. Biol. 52 741-55). We find that the SVM is slightly more accurate on average (1-3%) than

Endoscopy dose examinations at the Sao Paulo University Hospital

International Nuclear Information System (INIS)

Aldred, M.A.; Siqueira P, W.; Fonseca F, A.M. da; Nucci, J.R.; Yoshimura, E. M.; Okuno, E.

1996-01-01

During some specific endoscopic examinations, radiographic and fluoroscopic images of patients are taken with the medical staff near to them. To evaluate the equivalent and effective doses in these occupational exposures, simulated examinations have been performed, using an anthropomorphic phantom in place of one of the members of the staff. Thermoluminescent dosimeters were attached in various positions of the phantom in order to determine some organ doses. From the comparison between the experimentally determined doses the International and the Brazilian recommended occupational dose limits, the maximum number of examinations that any member of the staff can perform, was calculated. If a protective apron is used, this number is limited by the high equivalent dose to the eye lens (average of 1.67 mSv/examination) of the staff's member. (authors). 3 refs., 4 tabs

A radiographic examination system

International Nuclear Information System (INIS)

Cable, A.P.; Cable, W.S.

1983-01-01

A system for performing radiographic examination, particularly of large items such as international container units is disclosed. The system is formed as an installation comprising housings for respective linear accelerators transmitting a beam of radiation across the path of a conveyor along which the units can be displaced continuously or incrementally. On either end of the installation are container handling areas including roller conveyors with drag chains and transverse manipulators, and the whole installation is secured within automatically operated doors which seal the high energy region when a container on the conveyor is being subjected to examination. The radiation transmitted through a container is detected in a detector system incorporating a fluoroscopic screen light output from which is detected in a camera system such as a television camera, and transmitted as coded pulsed signals by a coding transfer unit to display screens where an image of the transmitted information can be displayed and/or recorded for further use. (author)

Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

International Nuclear Information System (INIS)

Lubis, L E; Badawy, M K

2016-01-01

The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care. (paper)

Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy

International Nuclear Information System (INIS)

Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Awai, Kazuo; Matsumoto, Tomohiro; Hasebe, Terumitsu; Kakizawa, Hideaki; Toyoda, Naoyuki

2014-01-01

This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. (orig.)

Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy

Energy Technology Data Exchange (ETDEWEB)

Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Awai, Kazuo [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Matsumoto, Tomohiro; Hasebe, Terumitsu [Tokai University Hachioji Hospital, Tokai University School of Medicine, Department of Radiology, Hachioji, Tokyo (Japan); Kakizawa, Hideaki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Hiroshima Red Cross Hospital and Atomic-bomb Survivors Hospital, Department of Diagnostic Radiology, Naka-Ku, Hiroshima (Japan); Toyoda, Naoyuki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); National Hospital Organisation Kure Medical Centre, Department of Diagnostic Radiology, Kure, Hiroshima (Japan)

2014-05-15

This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. (orig.)

Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge

Science.gov (United States)

Jalali, Maryam; Farahmand, Farzam; Mousavi, Seyed Mohammad Ebrahim; Golestanha, Seyed Ali; Rezaeian, Tahmineh; Shirvani Broujeni, Shahram; Rahgozar, Mehdi; Esfandiarpour, Fateme

2015-01-01

Background: Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. Objectives: In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL) injured patients. Patients and Methods: For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results: Results indicated that the overall anterior translations of the tibia during the eccentric (down) and concentric (up) phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Conclusion: Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL deficient

Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge.

Science.gov (United States)

Jalali, Maryam; Farahmand, Farzam; Mousavi, Seyed Mohammad Ebrahim; Golestanha, Seyed Ali; Rezaeian, Tahmineh; Shirvani Broujeni, Shahram; Rahgozar, Mehdi; Esfandiarpour, Fateme

2015-07-01

Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL) injured patients. For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results indicated that the overall anterior translations of the tibia during the eccentric (down) and concentric (up) phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL deficient patients during lunge exercise.

Value of Examination Under Fluoroscopy for the Assessment of Sacroiliac Joint Dysfunction.

Science.gov (United States)

Eskander, Jonathan P; Ripoll, Juan G; Calixto, Frank; Beakley, Burton D; Baker, Jeffrey T; Healy, Patrick J; Gunduz, O H; Shi, Lizheng; Clodfelter, Jamie A; Liu, Jinan; Kaye, Alan D; Sharma, Sanjay

2015-01-01

Pain emanating from the sacroiliac (SI) joint can have variable radiation patterns. Single physical examination tests for SI joint pain are inconsistent with multiple tests increasing both sensitivity and specificity. To evaluate the use of fluoroscopy in the diagnosis of SI joint pain. Prospective double blind comparison study. Pain clinic and radiology setting in urban Veterans Administration (VA) in New Orleans, Louisiana. Twenty-two adult men, patients at a southeastern United States VA interventional pain clinic, presented with unilateral low back pain of more than 2 months' duration. Patients with previous back surgery were excluded from the study. Each patient was given a Gapping test, Patrick (FABERE) test, and Gaenslen test. A second blinded physician placed each patient prone under fluoroscopic guidance, asking each patient to point to the most painful area. Pain was provoked by applying pressure with the heel of the palm in that area to determine the point of maximum tenderness. The area was marked with a radio-opaque object and was placed on the mark with a fluoroscopic imgage. A site within 1 cm of the SI joint was considered as a positive test. This was followed by a diagnostic injection under fluoroscopy with 1 mL 2% lidocaine. A positive result was considered as more than 2 hours of greater than 75% reduction in pain. Then, in 2-3 days this was followed by a therapeutic injection under fluoroscopy with 1 mL 0.5% bupivacaine and 40 mg methylprednisolone. Each patient was reassessed after 6 weeks. The sensitivity and specificity in addition to the positive and negative predictive values were determined for both the conventional examinations, as well as the examination under fluoroscopy. Finally, a receiver operating characteristic (ROC) curve was constructed to evaluate test performance. The sensitivity and specificity of the fluoroscopic examination were 0.82 and 0.80 respectively; Positive predictive value and negative predictive value were 0.93 and

An exploration of fluoroscopically guided spinal steroid injections in patients with non-specific exercise-related lower-limb pain

Directory of Open Access Journals (Sweden)

Leon Neve

2010-09-01

Full Text Available Leon Neve1, John Orchard2, Nathan Gibbs3, Willem van Mechelen4, Evert Verhagen4, Ken Sesel5, Ian Burgess6, Brett Hines61VU University, Amsterdam, The Netherlands; 2School of Public Health, University of Sydney, Sydney, NSW, Australia; 3South Sydney Sports Medicine, Sydney, NSW, Australia; 4EMGO, VU University, Amsterdam, The Netherlands; 5Sydney X-ray Centre, Sydney, NSW, Australia; 6Mater Imaging, Sydney, NSW, AustraliaBackground: Fluoroscopically guided lumbar cortisone injections have been proven useful in cases of lower-limb pain caused by lumbar disc prolapse (with evidence levels ll-1/ll-2. These injections are also sometimes used clinically in sports medicine for patients with non-specific exercise-related lower-limb pain, where no prolapse or other obvious cause of nerve-impingement is diagnosed via magnetic resonance imaging (MRI or computed tomography (CT, even though this treatment scenario has not been adequately studied for this last diagnosis.Objectives: To explore whether fluoroscopically guided transforaminal lumbar cortisone injections may be a valid treatment method for non-specific exercise-related lower-limb pain.Study design: Retrospective case series.Methods: Patients were selected from databases at two sports clinics and divided into two groups: Group D, with back-related lower-limb pain and disc prolapse proven on CT or MR; and Group N, with non-specific exercise-related lower-limb pain. Patients were sent a questionnaire regarding: symptoms, improvement, effect of injections, satisfaction, side effects and other used treatments. Outcomes were compared between Group D and N.Results: 153 patients were eligible for the study (Group D: 93/Group N: 60. Eventually 110 patients responded (Group D: 67/Group N: 43. Twelve percent of Group D and 14% of Group N indicated that the injections had fully cured their symptoms. Altogether, 27% of Group D and 24% of Group N were certain the injections had improved their symptoms in the

SU-E-I-42: Normalized Embryo/fetus Doses for Fluoroscopically Guided Pacemaker Implantation Procedures Calculated Using a Monte Carlo Technique

Energy Technology Data Exchange (ETDEWEB)

Damilakis, J; Stratakis, J; Solomou, G [University of Crete, Heraklion (Greece)

2014-06-01

Purpose: It is well known that pacemaker implantation is sometimes needed in pregnant patients with symptomatic bradycardia. To our knowledge, there is no reported experience regarding radiation doses to the unborn child resulting from fluoroscopy during pacemaker implantation. The purpose of the current study was to develop a method for estimating embryo/fetus dose from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all trimesters of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study. Three mathematical anthropomorphic phantoms representing the average pregnant patient at the first, second and third trimesters of gestation were generated using Bodybuilder software (White Rock science, White Rock, NM). The normalized embryo/fetus dose from the posteroanterior (PA), the 30° left-anterior oblique (LAO) and the 30° right-anterior oblique (RAO) projections were calculated for a wide range of kVp (50–120 kVp) and total filtration values (2.5–9.0 mm Al). Results: The results consist of radiation doses normalized to a) entrance skin dose (ESD) and b) dose area product (DAP) so that the dose to the unborn child from any fluoroscopic technique and x-ray device used can be calculated. ESD normalized doses ranged from 0.008 (PA, first trimester) to 2.519 μGy/mGy (RAO, third trimester). DAP normalized doses ranged from 0.051 (PA, first trimester) to 12.852 μGy/Gycm2 (RAO, third trimester). Conclusion: Embryo/fetus doses from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all stages of gestation can be estimated using the method developed in this study. This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ‘Education and Lifelong Learning’, ARISTIA (Research project: CONCERT)

SU-E-I-42: Normalized Embryo/fetus Doses for Fluoroscopically Guided Pacemaker Implantation Procedures Calculated Using a Monte Carlo Technique

International Nuclear Information System (INIS)

Damilakis, J; Stratakis, J; Solomou, G

2014-01-01

Purpose: It is well known that pacemaker implantation is sometimes needed in pregnant patients with symptomatic bradycardia. To our knowledge, there is no reported experience regarding radiation doses to the unborn child resulting from fluoroscopy during pacemaker implantation. The purpose of the current study was to develop a method for estimating embryo/fetus dose from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all trimesters of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study. Three mathematical anthropomorphic phantoms representing the average pregnant patient at the first, second and third trimesters of gestation were generated using Bodybuilder software (White Rock science, White Rock, NM). The normalized embryo/fetus dose from the posteroanterior (PA), the 30° left-anterior oblique (LAO) and the 30° right-anterior oblique (RAO) projections were calculated for a wide range of kVp (50–120 kVp) and total filtration values (2.5–9.0 mm Al). Results: The results consist of radiation doses normalized to a) entrance skin dose (ESD) and b) dose area product (DAP) so that the dose to the unborn child from any fluoroscopic technique and x-ray device used can be calculated. ESD normalized doses ranged from 0.008 (PA, first trimester) to 2.519 μGy/mGy (RAO, third trimester). DAP normalized doses ranged from 0.051 (PA, first trimester) to 12.852 μGy/Gycm2 (RAO, third trimester). Conclusion: Embryo/fetus doses from fluoroscopically guided pacemaker implantation procedures performed on pregnant patients during all stages of gestation can be estimated using the method developed in this study. This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ‘Education and Lifelong Learning’, ARISTIA (Research project: CONCERT)

Repeating and non-repeating fast radio bursts from binary neutron star mergers

Science.gov (United States)

Yamasaki, Shotaro; Totani, Tomonori; Kiuchi, Kenta

2018-04-01

Most fast radio bursts (FRB) do not show evidence of repetition, and such non-repeating FRBs may be produced at the time of a merger of binary neutron stars (BNS), provided that the BNS merger rate is close to the high end of the currently possible range. However, the merger environment is polluted by dynamical ejecta, which may prohibit the radio signal from propagating. We examine this by using a general-relativistic simulation of a BNS merger, and show that the ejecta appears about 1 ms after the rotation speed of the merged star becomes the maximum. Therefore there is a time window in which an FRB signal can reach outside, and the short duration of non-repeating FRBs can be explained by screening after ejecta formation. A fraction of BNS mergers may leave a rapidly rotating and stable neutron star, and such objects may be the origin of repeating FRBs like FRB 121102. We show that a merger remnant would appear as a repeating FRB on a time scale of ˜1-10 yr, and expected properties are consistent with the observations of FRB 121102. We construct an FRB rate evolution model that includes these two populations of repeating and non-repeating FRBs from BNS mergers, and show that the detection rate of repeating FRBs relative to non-repeating ones rapidly increases with improving search sensitivity. This may explain why only the repeating FRB 121102 was discovered by the most sensitive FRB search with Arecibo. Several predictions are made, including the appearance of a repeating FRB 1-10 yr after a BNS merger that is localized by gravitational waves and subsequent electromagnetic radiation.

Fluoroscopically-guided transnasal insertion of ileus tube intestinal decompression in patients with inoperable malignant bowel obstruction

International Nuclear Information System (INIS)

Fang Shiming; Li Haili; Lin Qing; Mao Aiwu; Wu Shaoqiu; Jiang Haosheng; Cao Yan; Wang Zhenlei

2011-01-01

Objective: To assess the technical feasibility and effectiveness of fluoroscopically-guided transnasal insertion of ileus tube for intestinal decompression in the treatment of inoperable malignant bowel obstruction. Methods: A total of 211 patients with inoperable malignant bowel obstruction were enrolled in this study. The median KPS scale was 40 (ranged from 20 to 60). Under fluoroscopic guidance, transnasal insertion of ileus tube by using conventional technique or guidewire-catheter exchange technique was performed in all patients. The technical success rate, the clinical effective rate, the curative rate and adverse reactions as well as complications were documented. The correlation among the obstructive sites, obstruction causes and therapeutic effectiveness was analyzed. The ileus tube used in this study was a four-cavity and double-balloon catheter with a diameter of 16 F/18 f, which is produced by Cliny Company. Results: Transnasal drainage tube was successfully inserted into the proximal jejunum in all 211 patients with malignant bowel obstruction, and the total technical success rate was 100%. The initial technical success rate of the traditional technique and the catheter-guidewire exchange method was 85.5% (65/76) and 100% (135/135) respectively, the difference between the two was significant (P<0.05). After 24 hours, the clinical remission rate in the patients with high-level intestinal obstruction, lower-level intestinal obstruction and colorectal obstruction was 95.8% (46/48), 92.9% (117/126) and 83.8% (31/37), respectively. A follow-up of 4-245 days (mean 138 days) was conducted, and the total clinical cure rate was 27.5% (58/211). The clinical cure rate in small intestine obstruction and colorectal obstruction caused by primary tumor or recurrence was 12.7% (20/157) and 59.5% (22/37), respectively (P<0.05). The adverse reactions and complications included uncomfortable pharynx feeling or pain (99.1%, 199/221), the tube obstruction (23.2%, 49

Accuracy and repeatability of quantitative fluoroscopy for the measurement of sagittal plane translation and finite centre of rotation in the lumbar spine.

Science.gov (United States)

Breen, Alexander; Breen, Alan

2016-07-01

Quantitative fluoroscopy (QF) was developed to measure intervertebral mechanics in vivo and has been found to have high repeatability and accuracy for the measurement of intervertebral rotations. However, sagittal plane translation and finite centre of rotation (FCR) are potential measures of stability but have not yet been fully validated for current QF. This study investigated the repeatability and accuracy of QF for measuring these variables. Repeatability was assessed from L2-S1 in 20 human volunteers. Accuracy was investigated using 10 consecutive measurements from each of two pairs of linked and instrumented dry human vertebrae as reference; one which tilted without translation and one which translated without tilt. The results found intra- and inter-observer repeatability for translation to be 1.1mm or less (SEM) with fair to substantial reliability (ICC 0.533-0.998). Intra-observer repeatability of FCR location for inter-vertebral rotations of 5° and above ranged from 1.5mm to 1.8mm (SEM) with moderate to substantial reliability (ICC 0.626-0.988). Inter-observer repeatability for FCR ranged from 1.2mm to 5.7mm, also with moderate to substantial reliability (ICC 0.621-0.878). Reliability was substantial (ICC>0.81) for 10/16 measures for translation and 5/8 for FCR location. Accuracy for translation was 0.1mm (fixed centre) and 2.2mm (moveable centre), with an FCR error of 0.3mm(x) and 0.4mm(y) (fixed centre). This technology was found to have a high level of accuracy and with a few exceptions, moderate to substantial repeatability for the measurement of translation and FCR from fluoroscopic motion sequences. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Repeated DNA sequences in fungi

Energy Technology Data Exchange (ETDEWEB)

Dutta, S K

1974-11-01

Several fungal species, representatives of all broad groups like basidiomycetes, ascomycetes and phycomycetes, were examined for the nature of repeated DNA sequences by DNA:DNA reassociation studies using hydroxyapatite chromatography. All of the fungal species tested contained 10 to 20 percent repeated DNA sequences. There are approximately 100 to 110 copies of repeated DNA sequences of approximately 4 x 10/sup 7/ daltons piece size of each. Repeated DNA sequence homoduplexes showed on average 5/sup 0/C difference of T/sub e/50 (temperature at which 50 percent duplexes dissociate) values from the corresponding homoduplexes of unfractionated whole DNA. It is suggested that a part of repetitive sequences in fungi constitutes mitochondrial DNA and a part of it constitutes nuclear DNA. (auth)

A digital fluoroscopic imaging system for verification during external beam radiotherapy

International Nuclear Information System (INIS)

Takai, Michikatsu

1990-01-01

A digital fluoroscopic (DF) imaging system has been constructed to obtain portal images for verification during external beam radiotherapy. The imaging device consists of a fluorescent screen viewed by a highly sensitive video camera through a mirror. The video signal is digitized and processed by an image processor which is linked on-line with a host microcomputer. The image quality of the DF system was compared with that of film for portal images of the Burger phantom and the Alderson anthropomorphic phantom using 10 MV X-rays. Contrast resolution of the DF image integrated for 8.5 sec. was superior to the film resolution, while spatial resolution was slightly inferior. The DF image of the Alderson phantom processed by the adaptive histogram equalization was better in showing anatomical landmarks than the film portal image. The DF image integrated for 1 sec. which is used for movie mode can show patient movement during treatment. (author)

Radiation injury of the skin following diagnostic and interventional fluoroscopic procedures

International Nuclear Information System (INIS)

Koenig, T.R.; Wagner, L.K.; Mettler, F.A.

2001-01-01

Many radiation injuries to the skin, resulting from diagnostic and interventional fluoroscopic procedures, have been reported in recent years. In some cases skin damage was severe and debilitating. We analyzed 72 reports of skin injuries for progression and location of injury, type and number of procedures, and contributing patient and operator factors. Most cases (46) were related to coronary angiography and percutaneous transluminal coronary angioplasty (PTCA). A smaller number was documented after cardiac radiofrequency catheter ablation (12), transjugular intrahepatic portosystemic shunt (TIPS) placement (7), neuroradiological interventions (3) and other procedures (4). Important factors leading to skin injuries were long exposure times over the same skin area, use of high dose rates, irradiation through thick tissue masses, hypersensitivity to radiation, and positioning of arms or breasts into the radiation entrance beam. Physicians were frequently unaware of the high radiation doses involved and did not recognize the injuries as radiation induced. Based on these findings, recommendations to reduce dose and improve patient care are provided. (author)

Fluoroscopic removal of metallic foreign bodies in the stomach with a magnetic orogastric tube

International Nuclear Information System (INIS)

Paulson, E.K.; Jaffe, R.B.

1989-01-01

Thirty-six cases of metallic foreign bodies in the stomach were referred for fluoroscopically guided removal by means of a 5-mm diameter magnet coupled to an orogastric tube. The foreign bodies included 29 disk batteries, two nails, two screws, a nut and bolt, an unopened jack knife, and a metallic whistle. The average patient age was 4 years (range, 11 months to 13 years). Removal was successful in 33 of the 36 cases (92%). The three failures were the result of inadvertent passage of the foreign body into the duodenum (two cases) and lack of magnetic attraction (one case). There were no complications. No patient required general anesthesia, hospital admission, or endoscopic surgical intervention

Clinical comparison between 100 mm photofluorography and digital (1024/sup 2/) fluoroscopic image acquisition

International Nuclear Information System (INIS)

Hynes, D.M.; Edmonds, E.W.; Rowlands, J.A.; Porter, A.J.; Toth, B.D.

1986-01-01

The authors describe current work in progress in which a clinical image can be recorded on both 100-mm film and a 1,024/sup 2/ image store with the same exposure. The 100-mm film is exposed in the usual manner. However, the same radiation exposure is utilized by the optics of the beam splitter to transfer the output image of the intensifier into a 1,024/sup 2/ image store and thence to hard copy by multiformat camera or laser printer. Comparative phantom and clinical images will be presented, along with observations on dose rates needed for diagnostic digital imaging. Use of this system may allow fluoroscopic dose rates to be reduced

Revisiting the TALE repeat.

Science.gov (United States)

Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

2014-04-01

Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

Characterization of MOSFET Dosimeter Angular Response Using a Spherical Phantom for Fluoroscopic Dosimetry.

Science.gov (United States)

Wang, Chu; Hill, Kevin; Yoshizumi, Terry

2016-01-01

Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET) dosimeters, placed in anthropomorphic phantoms, are a standard method for organ dosimetry in medical x-ray imaging applications. However, many x-ray applications, particularly fluoroscopy procedures, use variable projection angles. During dosimetry, the MOSFET detector active area may not always be perpendicular to the x-ray beam. The goal of this study was to characterize the dosimeter's angular response in the fluoroscopic irradiation involved in pediatric cardiac catheterization procedures, during which a considerable amount of fluoroscopic x-ray irradiation is often applied from various projection angles. A biological x-ray irradiator was used to simulate the beam quality of a biplane fluoroscopy imaging system. A custom-designed acrylic spherical scatter phantom was fabricated to measure dosimeter response (in mV) in two rotational axes, axial (ψ) and normal-to-axial (θ), in 30° increments, as well as four common oblique angles used in cardiac catheterization: a) 90° Left Anterior Oblique (LAO); b) 70° LAO/ 20° Cranial; c) 20° LAO/ 15° Cranial; and d) 30° Right Anterior Oblique (RAO). All results were normalized to the angle where the dosimeter epoxy is perpendicular to the beam or the Posterior-Anterior projection angle in the clinical setup. The relative response in the axial rotation was isotropic (within ± 10% deviation); that in the normal-to-axial rotation was isotropic in all angles except the ψ = 270° angle, where the relative response was 83 ± 9%. No significant deviation in detector response was observed in the four common oblique angles, with their relative responses being: a) 102 ± 3%; b) 90 ± 3%; c) 92 ± 3%; and d) 95 ± 3%, respectively. These angular correction factors will be used in future dosimetry studies for fluoroscopy. The spherical phantom may be useful for other applications, as it allows the measurement of dosimeter response in virtually all angles in the 3

Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

Energy Technology Data Exchange (ETDEWEB)

Mets, Onno M.; Gietema, Hester A.; Jong, Pim A. de [University Medical Center Utrecht, Radiology, Heidelberglaan 100, Postbus 85500, Utrecht (Netherlands); Isgum, Ivana; Mol, Christian P. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Zanen, Pieter [University Medical Center Utrecht, Pulmonology, Utrecht (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Centre, Radiology, Nijmegen (Netherlands); University Medical Center Utrecht, Radiology, Heidelberglaan 100, Postbus 85500, Utrecht (Netherlands)

2012-12-15

To determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers. We analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3 months. Inspiratory and expiratory low-dose CT was obtained using breath hold instructions. CT air trapping was defined as the percentage of voxels in expiratory CT with an attenuation below -856 HU (EXP{sub -856}) and the expiratory to inspiratory ratio of mean lung density (E/I-ratio{sub MLD}). Variation was determined using limits of agreement, defined as 1.96 times the standard deviation of the mean difference. The effect of both lung volume correction and breath hold reproducibility was determined. The limits of agreement for uncorrected CT air trapping measurements were -15.0 to 11.7 % (EXP{sub -856}) and -9.8 to 8.0 % (E/I-ratio{sub MLD}). Good breath hold reproducibility significantly narrowed the limits for EXP{sub -856} (-10.7 to 7.5 %, P = 0.002), but not for E/I-ratio{sub MLD} (-9.2 to 7.9 %, P = 0.75). Statistical lung volume correction did not improve the limits for EXP{sub -856} (-12.5 to 8.8 %, P = 0.12) and E/I-ratio{sub MLD} (-7.5 to 5.8 %, P = 0.17). Quantitative air trapping measures on low-dose CT of heavy smokers show considerable variation on repeat CT examinations, regardless of lung volume correction or reproducible breath holds. (orig.)

Supplementation of bone marrow aspirate-derived platelet-rich plasma for treating radiation-induced ulcer after cardiac fluoroscopic procedures: A preliminary report

Directory of Open Access Journals (Sweden)

Soh Nishimoto

2012-01-01

Full Text Available Background: The frequency of encountering radiodermatitis caused by X-ray fluoroscopic procedures for ischaemic heart disease is increasing. In severe cases, devastating ulcers with pain, for which conservative therapy is ineffective, emerge. Radiation-induced ulcers are notorious for being difficult to treat. Simple skin grafting often fails because of the poor state of the wound bed. A vascularized flap is a very good option. However, the non-adherence of the well-vascularized flap with the irradiated wound bed is frequently experienced. Aim: To ameliorate the irradiated wound bed, bone marrow-derived platelet-rich plasma (bm-PRP was delivered during the surgery. Materials and Methods: Four patients with severe cutaneous radiation injury accompanied by unbearable pain after multiple fluoroscopic procedures for ischaemic heart disease were treated. Wide excision of the lesion and coverage with a skin flap supplemented with bm-PRP injection was performed. Results: All patients obtained wound closure and were relieved from pain. No complication concerning the bone marrow aspiration and delivery of bm-PRP was observed. Conclusions: Supplementation of bm-PRP can be an option without major complications, time, and cost to improve the surgical outcome for irradiated wounds.

Value of radiographic examination of the knee joint for the orthopedic surgeon

International Nuclear Information System (INIS)

Pietsch, M.; Hofmann, S.

2006-01-01

Extended radiographic examinations offer excellent options for diagnosis and strategy for treatment of the knee joint. The whole-leg radiograph is indispensable in measuring alignment for osteotomy or total knee arthroplasty (TKA). Fluoroscopically assisted varus-valgus stress radiographs provide the possibility for verifying mechanical function of the implanted knee prosthesis. Ultrasound examinations have been widely replaced by magnetic resonance imaging (MRI). MRI is the golden standard to examine intra-articular structures of the knee (meniscus, ligaments, cartilage) and surrounding soft tissue. For evaluating femoral and tibial torsion and determining axial rotation of TKA, computed tomography (CT) is best qualified. Imaging of the patellofemoral joint (patella instability) is difficult; CT scans in combination with true lateral radiographs seem to be helpful. (orig.) [de

Clinical significance of fluoroscopic patterns specific for the mitotic spindle in patients with reumatic diseases

Directory of Open Access Journals (Sweden)

S. Todesco

2011-09-01

Full Text Available Objective: we proposed to determine the clinical significance of anti-NuMA and anti-HsEg5 antibodies in a group of patients affected with rheumatic diseases. Materials and methods: indirect immunofluorescence on HEp-2000 cells at serum dilution of 1:40 was used to examin 26 sera which had previously showed a “mitotic spindle” fluoroscopic pattern type during laboratory routine. Results: 21 sera (80,7% were identified with NuMA and 5 (19,3% with HsEg5 patterns alone or associated with other ANA patterns. However only patients with isolated positiveness and that is 15 with NuMA and 4 with HsEg5 stainings were included in this study. Of the NuMA positive patients 5 were affected with arthropathies associated to different forms of thyroiditis, 2 with seronegative arthritis, 2 with antiphospholipid syndrome, 1 with systemic lupus erythematosus (SLE, 1 with rheumatoid arthritis, 1 with sicca syndrome, 1 with undifferentiated connective tissue disease, 1 with Mycoplasma pneumaniae infection and 1 with retinal thrombosis. Of the HsEg5 positive patients 3 were affected with SLE and 1 with seronegative arthritis. Conclusions: NuMA does not prevail in any defined rheumatic disease, while HsEg5 staining were more frequent (75% in patients affected with SLE all of whom showing high antibody titres.

Fluoroscopic and CT enteroclysis in children: initial experience, technical feasibility, and utility

International Nuclear Information System (INIS)

Brown, Shanaree; Applegate, Kimberly E.; Sandrasegaran, Kumar; Jennings, S.G.; Garrett, Joshua; Maglinte, Dean T.; Skantharajah, Arunan

2008-01-01

Partial small-bowel obstruction can be difficult to diagnose on clinical examination. These obstructions might not be detected on routine abdominal/pelvic CT. To evaluate the feasibility, safety, and techniques of fluoroscopic enteroclysis (FE) and CT enteroclysis (CTE), and to review their indications and findings in children. We retrospectively reviewed all enteroclysis studies in children younger than 18 years performed between January 2002 and March 2007. We correlated the results with other abdominal imaging and surgical and pathological findings. The review revealed 112 FE and 74 CTE studies performed in 175 children (mean age 14 years, range 3-18 years). FE and CTE studies were performed most commonly for evaluation of known Crohn disease (FE 38%, CTE 29%) and abdominal pain (FE 26%, CTE 26%). One FE study was terminated because of patient anxiety, and one CTE study was terminated because of patient discomfort. No complications of FE or CTE were reported. The findings were normal in 54% of the FE studies and 46% of the CTE studies. The most common small bowel diagnoses were Crohn disease (FE 34%, CTE 28%) and partial small bowel obstruction (FE 3%, CTE 10%). Two FE studies (2%) and 14 CTE studies (19%) showed abnormalities outside the small bowel. In 54 patients with inflammatory bowel disease, 11 FE studies and 25 CTE studies showed additional bowel abnormalities. Overall, 14 and 21 patients had surgery as a result of the findings of FE and CTE, respectively. FE and CTE are safe, feasible, and accurate in depicting small-bowel pathology in children. These techniques can be particularly useful in children with Crohn disease involving the small bowel. (orig.)

Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures

International Nuclear Information System (INIS)

Sandblom, V; Almén, A; Cederblad, A.; Båth, M; Lundh, C; Mai, T; Rystedt, H

2013-01-01

Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of the present study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection in fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff were compared to radiation doses collected when the radiation dose rates were displayed. When the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose (H p (10)) per procedure decreased from 68 to 28 μSv (p = 0.003) for this cardiologist and from 4.3 to 2.5 μSv (p = 0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection. (paper)

Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

Energy Technology Data Exchange (ETDEWEB)

Shah, Sweta [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Desouches, Stephane L. [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); St. Luke' s Hospital, Department of Radiology, Kansas City, MO (United States); Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Children' s Mercy Hospitals and Clinics, Department of Radiology, Kansas City, MO (United States)

2014-07-24

Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

International Nuclear Information System (INIS)

Shah, Sweta; Desouches, Stephane L.; Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton

2015-01-01

Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

Radiation exposure of the UK population from medical and dental x-ray examinations

International Nuclear Information System (INIS)

Hart, D.; Wall, B.F.

2002-03-01

Knowledge of recent trends in the radiation doses from x-ray examinations and their distribution for the UK population provides useful guidance on where best to concentrate efforts on patient dose reduction in order to optimise the protection of the population in a cost-effective manner. In this report, the results of a recent survey of the frequency of medical and dental x-ray examinations in the UK and contemporary data on the radiation doses typically received by patients, are used to assess trends in the extent and the pattern of the population exposure. Individual patient doses, expressed in terms of the effective dose, range from a few microsieverts for simple radiographic examinations of the teeth, limbs or chest to tens of millisieverts for prolonged fluoroscopic procedures or some computed tomography (CT) examinations. A total of about 41.5 million medical and dental x-ray examinations are now conducted each year in the UK (0.70 examination per head of population) resulting in an annual per caput effective dose of 330 μSv. This is not significantly different from the previous rough estimate of 350 μSv for 1991. However, over the last ten years CT has more than doubled its contribution and is now responsible for 40% of the total dose to the population from medical x-rays. In contrast, the contribution from conventional radiographic and fluoroscopic examinations has nearly halved to about 44%. Interventional and angiographic procedures together contribute the remaining 16%. The annual per caput dose of 330 μSv is low in comparison with other countries having similarly developed systems of health care. This is due to both a lower frequency of x-ray examinations per head of population and generally lower doses in the UK than in other developed countries. However, the much increased contributions of CT, angiography and interventional procedures to the UK population dose indicate an urgent need to develop radiation protection and optimisation activities for

Design considerations for a new, high resolution Micro-Angiographic Fluoroscope based on a CMOS sensor (MAF-CMOS).

Science.gov (United States)

Loughran, Brendan; Swetadri Vasan, S N; Singh, Vivek; Ionita, Ciprian N; Jain, Amit; Bednarek, Daniel R; Titus, Albert; Rudin, Stephen

2013-03-06

The detectors that are used for endovascular image-guided interventions (EIGI), particularly for neurovascular interventions, do not provide clinicians with adequate visualization to ensure the best possible treatment outcomes. Developing an improved x-ray imaging detector requires the determination of estimated clinical x-ray entrance exposures to the detector. The range of exposures to the detector in clinical studies was found for the three modes of operation: fluoroscopic mode, high frame-rate digital angiographic mode (HD fluoroscopic mode), and DSA mode. Using these estimated detector exposure ranges and available CMOS detector technical specifications, design requirements were developed to pursue a quantum limited, high resolution, dynamic x-ray detector based on a CMOS sensor with 50 μm pixel size. For the proposed MAF-CMOS, the estimated charge collected within the full exposure range was found to be within the estimated full well capacity of the pixels. Expected instrumentation noise for the proposed detector was estimated to be 50-1,300 electrons. Adding a gain stage such as a light image intensifier would minimize the effect of the estimated instrumentation noise on total image noise but may not be necessary to ensure quantum limited detector operation at low exposure levels. A recursive temporal filter may decrease the effective total noise by 2 to 3 times, allowing for the improved signal to noise ratios at the lowest estimated exposures despite consequent loss in temporal resolution. This work can serve as a guide for further development of dynamic x-ray imaging prototypes or improvements for existing dynamic x-ray imaging systems.

Fluoroscopically-guided transforaminal epidural steroid injection for the treatment of sciatica due to herniated nucleus pulposus

International Nuclear Information System (INIS)

Liu Xiao; Wang Jianhui; Duan Zhaohui; Xu Zhitao; Shu Xiaomin; Qiu Ronghua

2009-01-01

Objective: To discuss the therapeutic benefit of fluoroscopically-guided lumbar transforaminal epidural steroid injections (TFESI) in treating patients with sciatica due to a herniated nucleus pulposus. Methods: From October 2004 to November 2007, fluoroscopically-guided lumbar TFESI as performed in 79 patients (41 males and 38 females with a mean age of 45.75 years,ranged from 20 to 70 years) with sciatica due to a herniated nucleus pulposus. Patients had a symptomatic course of disease from 8 weeks to 22 years and showed no response to conservative treatment. The diagnosis was confirmed by computed tomography or magnetic resonance imaging. TFESI was performed at patient's request. Additional injections, up to 3 times, were given with an interval of 7 or 10 days. The injection medicine consisted of 25 mg of prednisolone acetate and (9-14) ml of 0.5% lidocaine. Patients were evaluated by an independent observer and received questionnaires before the initial injection and at 6,12 months after TFESI. Questionnaires included an eleven points visual analog scale (VAS) and a five points patient satisfaction scale. A successful outcome required a patient satisfaction scale score of 3 (very good) or 4(excellent) and a reduction on the VAS score of 2 or more points after TFESI. Pain relief was classified as 'excellent' when the pain was completely resolved or diminished by 5 points or more, as 'good' when a diminution of pain was 2 points or more, as 'fair' and 'poor' when a diminution of pain was 1 point or less, or even an increase in pain. Results: Twenty-nine patients received single injection, 22 patients received two, 15 patients received three and 13 patients received four times of injection, with a mean of 1.96 times per patient. The mean VAS scores were 6.5(ranged 3.5-9.5) before and 3.8(ranged 0-9.5) 6 months after the procedure. Pain relief was graded as excellent in 35 patients (44.3%), good in 26 patients(32.9%), fair in 10 patients(12.7%), and poor in 8

Fluoroscopic removal of retrievable self-expandable metal stents in patients with malignant oesophageal strictures: Experience with a non-endoscopic removal system.

Science.gov (United States)

Kim, Pyeong Hwa; Song, Ho-Young; Park, Jung-Hoon; Zhou, Wei-Zhong; Na, Han Kyu; Cho, Young Chul; Jun, Eun Jung; Kim, Jun Ki; Kim, Guk Bae

2017-03-01

To evaluate clinical outcomes of fluoroscopic removal of retrievable self-expandable metal stents (SEMSs) for malignant oesophageal strictures, to compare clinical outcomes of three different removal techniques, and to identify predictive factors of successful removal by the standard technique (primary technical success). A total of 137 stents were removed from 128 patients with malignant oesophageal strictures. Primary overall technical success and removal-related complications were evaluated. Logistic regression models were constructed to identify predictive factors of primary technical success. Primary technical success rate was 78.8 % (108/137). Complications occurred in six (4.4 %) cases. Stent location in the upper oesophagus (P=0.004), stricture length over 8 cm (P=0.030), and proximal granulation tissue (Pstent location in the upper oesophagus, and stricture length over 8 cm were negative predictive factors for primary technical success by standard extraction and may require a modified removal technique. • Fluoroscopic retrievable SEMS removal is safe and effective. • Standard removal technique by traction is effective in the majority of patients. • Three negative predictive factors of primary technical success were identified. • Caution should be exercised during the removal in those situations. • Eversion technique is effective in cases of proximal granulation tissue.

Complement consumption by double culture of Paramecium caudatum and Aerobacter cloacae in repeated examination in relation to the individual radiosensitivity

International Nuclear Information System (INIS)

Bernasovsky, I.; Cabadaj, S.; Praslicka, M.; Chlebovska, K.

1976-01-01

Two sets of rats were repeatedly examined by the complement consumption test with a double culture of Paramecium caudatum and Aerobacter cloacae (DPA). The first set was examined 11 days and 1 day before irradiation with 0.15 C/kg, the second 6 days before and 4 days after irradiation with 0.15 C/kg. The intensity of reaction and thus the relative titres of the examined antibodies were expressed numerically by the NMHD symbol, i.e., by the number of minimal hemolytical complement doses consumed in the reaction. This reaction is known as the NMHD test. The proportion of rats with a high NMHD which survived 30 days after irradiation was higher than that of rats with low reaction values. Rats having in one examination a high NMHD value and in the second a low one (the sequence high-low or low-high is not important) were more radioresistant than those with permanently low reaction values and did not basically differ from the animals with permanently high NMHD values. Bacteriae Aerobacter cloacae represent the antigenically effective substance of DNA. (author)

Complement consumption by double culture of Paramecium caudatum and Aerobacter cloacae in repeated examination in relation to the individual radiosensitivity

Energy Technology Data Exchange (ETDEWEB)

Bernasovsky, I; Cabadaj, S; Praslicka, M; Chlebovska, K [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

1976-01-01

Two sets of rats were repeatedly examined by the complement consumption test with a double culture of Paramecium caudatum and Aerobacter cloacae (DPA). The first set was examined 11 days and 1 day before irradiation with 0.15 C/kg, the second 6 days before and 4 days after irradiation with 0.15 C/kg. The intensity of reaction and thus the relative titres of the examined antibodies were expressed numerically by the NMHD symbol, i.e., by the number of minimal hemolytical complement doses consumed in the reaction. This reaction is known as the NMHD test. The proportion of rats with a high NMHD which survived 30 days after irradiation was higher than that of rats with low reaction values. Rats having in one examination a high NMHD value and in the second a low one (the sequence high-low or low-high is not important) were more radioresistant than those with permanently low reaction values and did not basically differ from the animals with permanently high NMHD values. Bacteriae Aerobacter cloacae represent the antigenically effective substance of DNA.

Radiation dosages absorbed by the skin during videofluorographic examination of velopharyngeal function

International Nuclear Information System (INIS)

Ohara, Hirotoshi; Ogata, Hisao; Nakajima, Tatsuo; Sone, Kiyoaki

2008-01-01

Radiographic assessment has become essential in examining the function of the soft palate and pharyngeal walls in patients with velopharyngeal insufficiency. However, in our search of the literature, there was no report on the exposure dose during videofluorographic examination of velopharyngeal function in Japan. Radiation dosages from videofluorography were measured by attaching a glass dosimeter to the submental skin in 17 patients undergoing examination of velopharyngeal function. Sixteen patients underwent a complete videofluorographic examination. For these 16 patients, the mean time of examination was 96.4 sec; the mean radiation dosage absorbed by the skin was 14.4 mGy, equivalent to approximately 7 standard skull x-rays and lower than that during other fluoroscopic procedures. This dose was also lower than the threshold dose at which the skin damage occurs. In light of increasing concern among the general public over radiation exposure, we consider that these data should provide useful information to patients being asked to give informed consent for this examination. (author)

Fluoroscopically guided caudal epidural steroid injection for management of degenerative lumbar spinal stenosis: short-term and long-term results

Energy Technology Data Exchange (ETDEWEB)

Lee, Joon Woo; Myung, Jae Sung; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Seong Nam, Gyeongi-do (Korea); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Seong Nam, Gyeongi-do (Korea); Kim, Ki-Jeong; Kim, Hyun-Jib [Seoul National University Bundang Hospital, Department of Neurosurgery, Seong Nam, Gyeongi-do (Korea)

2010-07-15

To evaluate the short-term and long-term effects of fluoroscopically guided caudal epidural steroid injection (ESI) for the management of degenerative lumbar spinal stenosis (DLSS) and to analyze outcome predictors. All patients who underwent caudal ESI in 2006 for DLSS were included in the study. Response was based on chart documentation (aggravated, no change, slightly improved, much improved, no pain). In June 2009 telephone interviews were conducted, using formatted questions including the North American Spine Society (NASS) patient satisfaction scale. For short-term and long-term effects, age difference was evaluated by the Mann-Whitney U test, and gender, duration of symptoms, level of DLSS, spondylolisthesis, and previous operations were evaluated by Fisher's exact test. Two hundred and sixteen patients (male: female = 75:141; mean age 69.2 years; range 48{proportional_to}91 years) were included in the study. Improvements (slightly improved, much improved, no pain) were seen in 185 patients (85.6%) after an initial caudal ESI and in 189 patients (87.5%) after a series of caudal ESIs. Half of the patients (89/179, 49.8%) replied positively to the NASS patient satisfaction scale (1 or 2). There were no significant outcome predictors for either the short-term or the long-term responses. Fluoroscopically guided caudal ESI was effective for the management of DLSS (especially central canal stenosis) with excellent short-term and good long-term results, without significant outcome predictors. (orig.)

The effect of repeated testing vs repeated practice on skills learning in undergraduate dental education.

Science.gov (United States)

Sennhenn-Kirchner, S; Goerlich, Y; Kirchner, B; Notbohm, M; Schiekirka, S; Simmenroth, A; Raupach, T

2018-02-01

Recent studies in undergraduate medical education have demonstrated the advantage of repeated testing over repeated practice with regard to knowledge and skills retention. The aim of this study was to investigate whether this "testing effect" also applies to skills retention in undergraduate dental education. In this prospective, randomised controlled trial, fourth-year dental students at Göttingen University Medical Centre participated in a training session on surgical suturing in winter term 2014/2015. Following this, they were either assigned to two sessions of additional skills training (group A) or two sessions of skills assessment with feedback (group B). These sessions were spaced over a period of 4 weeks. Skills retention was assessed in a summative objective structured clinical examination (OSCE) at the end of term, that is 6 months after the initial teaching session. A total of 32 students completed the study. With regard to suturing, OSCE performance was significantly better in group B than group A (81.9±13.1% vs 63.0±15.4%; P=0.001; Cohen's d=1.33). There was no significant OSCE performance difference in the two groups with regard to other learning objectives that were addressed in the end-of-term examination. Thus, the group difference was specific to suturing skills. This is the first study to demonstrate that in dental education, repeated testing produces more favourable skills retention than repeated practice. Test-enhanced learning might be a viable concept for skills retention in undergraduate dentistry education. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Effects of Repeated Experience on Children's Suggestibility.

Science.gov (United States)

Powell, Martine B.; Roberts, Kim P.; Ceci, Stephen J.; Hembrooke, Helene

1999-01-01

Examined effect of suggestive questions on 3- to 5-year-olds' and 6- to 8-year-olds' recall of the final occurrence of repeated event. Found that relative to reports of children experiencing single occurrence, reports about fixed items of repeated events were less contaminated by false suggestions. Children's age and delay of interview were…

Repeated Causal Decision Making

Science.gov (United States)

Hagmayer, York; Meder, Bjorn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

Discrepancy between fluoroscopic arthrography and magnetic resonance arthrography in patients with arthroscopically confirmed supraspinatus tendon tears: The additional benefit of cine fluoroscopic arthrography images

International Nuclear Information System (INIS)

Hahn, Seok; Lee, Young Han; Suh, Jin Suck

2016-01-01

To determine the additional diagnostic benefits of fluoroscopic arthrography (FA) in patients with full-thickness supraspinatus tendon (SST) tears by comparing FA images with magnetic resonance arthrography (MRA) images. This study included FA and MRA images of 53 patients who were confirmed to have full-thickness SST tears by arthroscopy. In the FA analysis, the presence of contrast leakage into the subacromial-subdeltoid bursa was recorded. In the MRA analysis, contrast leakage, retraction of a torn tendon, width and length of the tear, and supraspinatus atrophy were evaluated. Patients were divided into the concordant group or the discordant group based on the presence of contrast leakage to compare the characteristics of SST tears. We used Fisher's exact test and two-sample t-test for the comparison. Of the 53 patients, 34 were included in the concordant group and 19 were included in the discordant group. In the concordant group, the grades of retraction were higher than those in the discordant group; the width and length of the tears were larger. Muscle atrophy was more severe in the concordant group. A full-thickness SST tear did not always exhibit contrast leakage on FA, particularly small SST tears or tears with low-grade retraction. FA can provide diagnostic information regarding the severity of full-thickness SST tears by itself

Discrepancy between fluoroscopic arthrography and magnetic resonance arthrography in patients with arthroscopically confirmed supraspinatus tendon tears: The additional benefit of cine fluoroscopic arthrography images

Energy Technology Data Exchange (ETDEWEB)

Hahn, Seok; Lee, Young Han; Suh, Jin Suck [Dept. Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2016-12-15

To determine the additional diagnostic benefits of fluoroscopic arthrography (FA) in patients with full-thickness supraspinatus tendon (SST) tears by comparing FA images with magnetic resonance arthrography (MRA) images. This study included FA and MRA images of 53 patients who were confirmed to have full-thickness SST tears by arthroscopy. In the FA analysis, the presence of contrast leakage into the subacromial-subdeltoid bursa was recorded. In the MRA analysis, contrast leakage, retraction of a torn tendon, width and length of the tear, and supraspinatus atrophy were evaluated. Patients were divided into the concordant group or the discordant group based on the presence of contrast leakage to compare the characteristics of SST tears. We used Fisher's exact test and two-sample t-test for the comparison. Of the 53 patients, 34 were included in the concordant group and 19 were included in the discordant group. In the concordant group, the grades of retraction were higher than those in the discordant group; the width and length of the tears were larger. Muscle atrophy was more severe in the concordant group. A full-thickness SST tear did not always exhibit contrast leakage on FA, particularly small SST tears or tears with low-grade retraction. FA can provide diagnostic information regarding the severity of full-thickness SST tears by itself.

Dosimetry measurements of X-Ray machine operating at ordinary radiology and fluoroscopic examinations

International Nuclear Information System (INIS)

Ayad, M.; Bakazi, A.; Elharby, H.

2002-01-01

An assessment of radiation dose levels inside diagnostic radiology rooms at King Khalid University Hospital was made. The measurements were taken using lithium Flouride detectors Also, an assessment of doses received by patients during some radiographic examinations especially at fluoroscopy has been measured. It has been noted that when rare-earth image intensifying screens were used the radiation dose received by the patient was reduced by 60%. It has been shown that a lead glass viewer caused a reduction of the radiation intensity by more than 50%. The variation of dose rate with the operating conditions of the X-ray tube has been studied, as well as the machine factor (P)

Reject/repeat analysis and the effect prior film viewing has on a department's reject/repeat rate

International Nuclear Information System (INIS)

Clark, P.A.; Hogg, P.

2003-01-01

Purpose: Achieving cost-effectiveness within the NHS is an old initiative but one that has again been highlighted by recent government policies (The New NHS-Modern and Dependable, Stationary Office, London, 1997). It has been reiterated that it is the responsibility of individual Trusts to devise means to provide such a service. Reject/repeat analyses have long been the primary tool used to assess the cost-effectiveness of radiography departments (Quality Assurance in Diagnostic Radiology, WHO, Geneva, 1982). This research paper examines an in-house initiative (viewing patients' previous films) commonly employed in other Health Trusts in order to reduce departmental repeat/reject rates. Method: Three hundred orthopaedic patients with hip, knee and ankle prostheses were included in a reject/repeat analysis. The aim was to investigate whether or not viewing patient's previous relevant radiographs would be advantageous to the practicing radiographer. This was done through an audit cycle consisting of two audit periods each lasting for 3 months. The primary audit period recorded the baseline repeat/reject rate, with the secondary audit period recording the repeat/reject rate under an experimental condition of viewing the relevant radiographs. Results: The baseline audit revealed repeat rates of 33% in orthopaedic patients with hip, knee and ankle prostheses. The availability of prior film viewing to the radiographer reduced this repeat rate to 10.6%. Conclusion: Prior film viewing dramatically reduced the department's repeat/reject rate by 22.4%. This provides scope for significant patient dose reductions as well as reducing departmental film expenses. This is an underestimated initiative and should be used appropriately in routine clinical practice

TU-D-209-03: Alignment of the Patient Graphic Model Using Fluoroscopic Images for Skin Dose Mapping

Energy Technology Data Exchange (ETDEWEB)

Oines, A; Oines, A; Kilian-Meneghin, J; Karthikeyan, B; Rudin, S; Bednarek, D [University at Buffalo (SUNY) School of Med., Buffalo, NY (United States)

2016-06-15

Purpose: The Dose Tracking System (DTS) was developed to provide realtime feedback of skin dose and dose rate during interventional fluoroscopic procedures. A color map on a 3D graphic of the patient represents the cumulative dose distribution on the skin. Automated image correlation algorithms are described which use the fluoroscopic procedure images to align and scale the patient graphic for more accurate dose mapping. Methods: Currently, the DTS employs manual patient graphic selection and alignment. To improve the accuracy of dose mapping and automate the software, various methods are explored to extract information about the beam location and patient morphology from the procedure images. To match patient anatomy with a reference projection image, preprocessing is first used, including edge enhancement, edge detection, and contour detection. Template matching algorithms from OpenCV are then employed to find the location of the beam. Once a match is found, the reference graphic is scaled and rotated to fit the patient, using image registration correlation functions in Matlab. The algorithm runs correlation functions for all points and maps all correlation confidences to a surface map. The highest point of correlation is used for alignment and scaling. The transformation data is saved for later model scaling. Results: Anatomic recognition is used to find matching features between model and image and image registration correlation provides for alignment and scaling at any rotation angle with less than onesecond runtime, and at noise levels in excess of 150% of those found in normal procedures. Conclusion: The algorithm provides the necessary scaling and alignment tools to improve the accuracy of dose distribution mapping on the patient graphic with the DTS. Partial support from NIH Grant R01-EB002873 and Toshiba Medical Systems Corp.

TU-D-209-03: Alignment of the Patient Graphic Model Using Fluoroscopic Images for Skin Dose Mapping

International Nuclear Information System (INIS)

Oines, A; Oines, A; Kilian-Meneghin, J; Karthikeyan, B; Rudin, S; Bednarek, D

2016-01-01

Purpose: The Dose Tracking System (DTS) was developed to provide realtime feedback of skin dose and dose rate during interventional fluoroscopic procedures. A color map on a 3D graphic of the patient represents the cumulative dose distribution on the skin. Automated image correlation algorithms are described which use the fluoroscopic procedure images to align and scale the patient graphic for more accurate dose mapping. Methods: Currently, the DTS employs manual patient graphic selection and alignment. To improve the accuracy of dose mapping and automate the software, various methods are explored to extract information about the beam location and patient morphology from the procedure images. To match patient anatomy with a reference projection image, preprocessing is first used, including edge enhancement, edge detection, and contour detection. Template matching algorithms from OpenCV are then employed to find the location of the beam. Once a match is found, the reference graphic is scaled and rotated to fit the patient, using image registration correlation functions in Matlab. The algorithm runs correlation functions for all points and maps all correlation confidences to a surface map. The highest point of correlation is used for alignment and scaling. The transformation data is saved for later model scaling. Results: Anatomic recognition is used to find matching features between model and image and image registration correlation provides for alignment and scaling at any rotation angle with less than onesecond runtime, and at noise levels in excess of 150% of those found in normal procedures. Conclusion: The algorithm provides the necessary scaling and alignment tools to improve the accuracy of dose distribution mapping on the patient graphic with the DTS. Partial support from NIH Grant R01-EB002873 and Toshiba Medical Systems Corp.

Concomitant Intracranial and Lumbar Chronic Subdural Hematoma Treated by Fluoroscopic Guided Lumbar Puncture: A Case Report and Literature Review

Science.gov (United States)

ICHINOSE, Daisuke; TOCHIGI, Satoru; TANAKA, Toshihide; SUZUKI, Tomoya; TAKEI, Jun; HATANO, Keisuke; KAJIWARA, Ikki; MARUYAMA, Fumiaki; SAKAMOTO, Hiroki; HASEGAWA, Yuzuru; TANI, Satoshi; MURAYAMA, Yuichi

2018-01-01

A 40-year-old man presented with a severe headache, lower back pain, and lower abdominal pain 1 month after a head injury caused by falling. Computed tomography (CT) of the head demonstrated bilateral chronic subdural hematoma (CSDH) with a significant amount in the left frontoparietal region. At the same time, magnetic resonance imaging (MRI) of the lumbar spine also revealed CSDH from L2 to S1 level. A simple drainage for the intracranial CSDH on the left side was performed. Postoperatively, the headache was improved; however, the lower back and abdominal pain persisted. Aspiration of the liquefied spinal subdural hematoma was performed by a lumbar puncture under fluoroscopic guidance. The clinical symptoms were dramatically improved postoperatively. Concomitant intracranial and spinal CSDH is considerably rare so only 23 cases including the present case have been reported in the literature so far. The etiology and therapeutic strategy were discussed with a review of the literature. Therapeutic strategy is not established for these two concomitant lesions. Conservative follow-up was chosen for 14 cases, resulting in a favorable clinical outcome. Although surgical evacuation of lumbosacral CSDH was performed in seven cases, an alteration of cerebrospinal fluid (CSF) pressure following spinal surgery should be reminded because of the intracranial lesion. Since CSDH is well liquefied in both intracranial and spinal lesion, a less invasive approach is recommended not only for an intracranial lesion but also for spinal lesion. Fluoroscopic-guided lumbar puncture for lumbosacral CSDH following burr hole surgery for intracranial CSDH could be a recommended strategy. PMID:29479039

Radiation dose to the operator during fluoroscopically guided spine procedures

Energy Technology Data Exchange (ETDEWEB)

Roccatagliata, Luca; Pravata, Emanuele; Cianfoni, Alessandro [Department of Neuroradiology, Neurocenter of Southern Switzerland, Ospedale Regionale di Lugano, Lugano (Switzerland); Presilla, Stefano [Unita di Fisica Medica, Ente Ospedaliero Cantonale (EOC), Bellinzona (Switzerland)

2017-09-15

Fluoroscopy is widely used to guide diagnostic and therapeutic spine procedures. The purpose of this study was to quantify radiation incident on the operator (operator Air Kerma) during a wide range of fluoroscopy-guided spine procedures and its correlation with the amount of radiation incident on the patient (Kerma Area Product - KAP). We retrospectively included 57 consecutive fluoroscopically guided spine procedures. KAP [Gy cm{sup 2}] and total fluoroscopy time were recorded for each procedure. An electronic dosimeter recorded the operator Air Kerma [μGy] for each procedure. Operator Air Kerma for each procedure, correlation between KAP and operator Air Kerma, and between KAP and fluoroscopy time was obtained. Operator Air Kerma was widely variable across procedures, with median value of 6.4 μGy per procedure. Median fluoroscopy time and median KAP per procedure were 2.6 min and 4.7 Gy cm{sup 2}, respectively. There was correlation between operator Air Kerma and KAP (r{sup 2} = 0.60), with a slope of 1.6 μGy Air Kerma per unit Gy cm{sup 2} KAP incident on the patient and between fluoroscopy time and KAP (r{sup 2} = 0.63). Operator Air Kerma during individual fluoroscopy-guided spine procedures can be approximated from the commonly and readily available information of the total amount of radiation incident on the patient, measured as KAP. (orig.)

Myotonin protein-kinase [AGC]n trinucleotide repeat in seven nonhuman primates

Energy Technology Data Exchange (ETDEWEB)

Novelli, G.; Sineo, L.; Pontieri, E. [Catholic Univ. of Rome (Italy)]|[Univ. of Milan (Italy)]|[Univ. Florence (Italy)] [and others

1994-09-01

Myotonic dystrophy (DM) is due to a genomic instability of a trinucleotide [AGC]n motif, located at the 3{prime} UTR region of a protein-kinase gene (myotonin protein kinase, MT-PK). The [AGC] repeat is meiotically and mitotically unstable, and it is directly related to the manifestations of the disorder. Although a gene dosage effect of the MT-PK has been demonstrated n DM muscle, the mechanism(s) by which the intragenic repeat expansion leads to disease is largely unknown. This non-standard mutational event could reflect an evolutionary mechanism widespread among animal genomes. We have isolated and sequenced the complete 3{prime}UTR region of the MT-PK gene in seven primates (macaque, orangutan, gorilla, chimpanzee, gibbon, owl monkey, saimiri), and examined by comparative sequence nucleotide analysis the [AGC]n intragenic repeat and the surrounding nucleotides. The genomic organization, including the [AGC]n repeat structure, was conserved in all examined species, excluding the gibbon (Hylobates agilis), in which the [AGC]n upstream sequence (GGAA) is replaced by a GA dinucleotide. The number of [AGC]n in the examined species ranged between 7 (gorilla) and 13 repeats (owl monkeys), with a polymorphism informative content (PIC) similar to that observed in humans. These results indicate that the 3{prime}UTR [AGC] repeat within the MT-PK gene is evolutionarily conserved, supporting that this region has important regulatory functions.

Upper cervical spine movement during intubation: fluoroscopic comparison of the AirWay Scope, McCoy laryngoscope, and Macintosh laryngoscope.

Science.gov (United States)

Maruyama, K; Yamada, T; Kawakami, R; Kamata, T; Yokochi, M; Hara, K

2008-01-01

The AirWay Scope (AWS) is a new fibreoptic intubation device, which allows visualization of the glottic structures without alignment of the oral, pharyngeal, and tracheal axes, and thus may be useful in patients with limited cervical spine (C-spine) movement. We fluoroscopically evaluated upper C-spine movement during intubation with the AWS or Macintosh or McCoy laryngoscope. Forty-five patients, with normal C-spine, scheduled for elective surgery were randomly assigned to one of the three intubation devices. Movement of the upper C-spine was examined by measuring angles formed by adjacent vertebrae during intubation. Time to intubation was also recorded. Median cumulative upper C-spine movement was 22.3 degrees, 32.3 degrees, and 36.5 degrees with the AWS, Macintosh laryngoscope, and McCoy laryngoscope, respectively (Pmovement of the C-spine at C1/C2 in comparison with the Macintosh or McCoy laryngoscope (P=0.012), and at C3/C4 in comparison with the McCoy laryngoscope (P=0.019). Intubation time was significantly longer in the AWS group than in the Macintosh group (P=0.03). Compared with the Macintosh or McCoy laryngoscope, the AWS produced less movement of upper C-spine for intubation in patients with a normal C-spine.

Pediatric patient and staff dose measurements in barium meal fluoroscopic procedures

Science.gov (United States)

Filipov, D.; Schelin, H. R.; Denyak, V.; Paschuk, S. A.; Porto, L. E.; Ledesma, J. A.; Nascimento, E. X.; Legnani, A.; Andrade, M. E. A.; Khoury, H. J.

2015-11-01

This study investigates patient and staff dose measurements in pediatric barium meal series fluoroscopic procedures. It aims to analyze radiographic techniques, measure the air kerma-area product (PKA), and estimate the staff's eye lens, thyroid and hands equivalent doses. The procedures of 41 patients were studied, and PKA values were calculated using LiF:Mg,Ti thermoluminescent dosimeters (TLDs) positioned at the center of the patient's upper chest. Furthermore, LiF:Mg,Cu,P TLDs were used to estimate the equivalent doses. The results showed a discrepancy in the radiographic techniques when compared to the European Commission recommendations. Half of the results of the analyzed literature presented lower PKA and dose reference level values than the present study. The staff's equivalent doses strongly depends on the distance from the beam. A 55-cm distance can be considered satisfactory. However, a distance decrease of ~20% leads to, at least, two times higher equivalent doses. For eye lenses this dose is significantly greater than the annual limit set by the International Commission on Radiological Protection. In addition, the occupational doses were found to be much higher than in the literature. Changing the used radiographic techniques to the ones recommended by the European Communities, it is expected to achieve lower PKA values ​​and occupational doses.

Patient doses from fluoroscopically guided cardiac procedures in pediatrics

International Nuclear Information System (INIS)

Martinez, L C; Vano, E; Gutierrez, F; Rodriguez, C; Gilarranz, R; Manzanas, M J

2007-01-01

Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for 2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers

Self-Expandable Metallic Stent for the Palliative Treatment of Obstructing Left-Sided Colorectal Cancer under Fluoroscopic Guidance: A Comparison of the Clinical Results according to Stent Diameter

Energy Technology Data Exchange (ETDEWEB)

Kang, Pyeong Guk; Hong, Hyun Pyo; Choi, Yoon Jung; Lee, Min Hee; Park, Hae Won; Chung, Eun Chul [Kangbuk Samsung Hospital, Seoul (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

2010-03-15

To evaluate the feasibility, effectiveness, and safety of self-expandable metallic stent for the palliative treatment of obstructing left-sided colorectal cancer under fluoroscopic guidance, and to compare results according to the stent diameter. Under fluoroscopic guidance, 31 self-expandable metallic stents were placed into 25 patients for palliative purposes. The rates of technical success, clinical success, complications associated with stent insertion, patient survival, and primary stent patency were evaluated. The results were also compared between two groups: 13 patients using stents with a diameter of 22 mm and 12 patients using stents with a diameter of 26 mm. The technical and clinical success rates were 93.5 and 90.3%, respectively. The complications included severe abdominal pain (6.5%), minor rectal bleeding (9.7%), stent migration (9.7%), and tumor ingrowth or overgrowth (9.7%). No statistical differences in technical were detected between the two groups for the clinical success rate and complication rates. The mean survival time was 5.5 +- 1.4 months. The primary stent patency rates were 91.3% at 5 months, 85.2% at 10 months, and 77.4% at 15 months. The mean period of stent patency was 12.4 +- 2.6 months. The mean period of primary stent patency was 16.4 +- 2.6 months in the 26 mm stent group, and significantly higher than 5.4 +- 1.4 months in the 22 mm stent group (p=0.031). A self-expandable metallic stent under fluoroscopic guidance, for the palliative treatment of obstructing left-sided colorectal cancer, was feasible and effective, and yielded good clinical results. The period of primary stent patency of the 26 mm stent group was longer than the 22 mm stent group, and the complication rate was not significantly different between the two stent groups

Self-Expandable Metallic Stent for the Palliative Treatment of Obstructing Left-Sided Colorectal Cancer under Fluoroscopic Guidance: A Comparison of the Clinical Results according to Stent Diameter

International Nuclear Information System (INIS)

Kang, Pyeong Guk; Hong, Hyun Pyo; Choi, Yoon Jung; Lee, Min Hee; Park, Hae Won; Chung, Eun Chul; Kim, Sam Soo

2010-01-01

To evaluate the feasibility, effectiveness, and safety of self-expandable metallic stent for the palliative treatment of obstructing left-sided colorectal cancer under fluoroscopic guidance, and to compare results according to the stent diameter. Under fluoroscopic guidance, 31 self-expandable metallic stents were placed into 25 patients for palliative purposes. The rates of technical success, clinical success, complications associated with stent insertion, patient survival, and primary stent patency were evaluated. The results were also compared between two groups: 13 patients using stents with a diameter of 22 mm and 12 patients using stents with a diameter of 26 mm. The technical and clinical success rates were 93.5 and 90.3%, respectively. The complications included severe abdominal pain (6.5%), minor rectal bleeding (9.7%), stent migration (9.7%), and tumor ingrowth or overgrowth (9.7%). No statistical differences in technical were detected between the two groups for the clinical success rate and complication rates. The mean survival time was 5.5 ± 1.4 months. The primary stent patency rates were 91.3% at 5 months, 85.2% at 10 months, and 77.4% at 15 months. The mean period of stent patency was 12.4 ± 2.6 months. The mean period of primary stent patency was 16.4 ± 2.6 months in the 26 mm stent group, and significantly higher than 5.4 ± 1.4 months in the 22 mm stent group (p=0.031). A self-expandable metallic stent under fluoroscopic guidance, for the palliative treatment of obstructing left-sided colorectal cancer, was feasible and effective, and yielded good clinical results. The period of primary stent patency of the 26 mm stent group was longer than the 22 mm stent group, and the complication rate was not significantly different between the two stent groups

Feasibility of differential quantification of 3D temporomandibular kinematics during various oral activities using a cone-beam computed tomography-based 3D fluoroscopic method

Directory of Open Access Journals (Sweden)

Chien-Chih Chen

2013-06-01

Conclusion: A new CBCT-based 3D fluoroscopic method was proposed and shown to be capable of quantitatively differentiating TMJ movement patterns among complicated functional activities. It also enabled a complete description of the rigid-body mandibular motion and descriptions of as many reference points as needed for future clinical applications. It will be helpful for dental practice and for a better understanding of the functions of the TMJ.

An assessment of methods for monitoring entrance surface dose in fluoroscopically guided interventional procedures

International Nuclear Information System (INIS)

Waite, J.C.; Fitzgerald, M.

2001-01-01

In the light of a growing awareness of the risks of inducing skin injuries as a consequence of fluoroscopically guided interventional procedures (FGIPs), this paper compares three methods of monitoring entrance surface dose (ESD). It also reports measurements of ESDs made during the period August 1998 to June 1999 on 137 patients undergoing cardiac, neurological and general FGIPs. Although the sample is small, the results reinforce the need for routine assessments to be made of ESDs in FGIPs. At present, the most reliable and accurate form of ESD measurement would seem to be arrays of TLDs. However, transducer based methods, although likely to be less accurate, have considerable advantages in relation to a continuous monitoring programme. It is also suggested that there may be the potential locally for threshold dose area product (DAP) values to be set for specific procedures. These could be used to provide early warning of the potential for skin injuries. (author)

Fluoroscopically guided tunneled trans-caudal epidural catheter technique for opioid-free neonatal epidural analgesia.

Science.gov (United States)

Franklin, Andrew D; Hughes, Elisabeth M

2016-06-01

Epidural analgesia confers significant perioperative advantages to neonates undergoing surgical procedures but may be very technically challenging to place using a standard interlaminar loss-of-resistance to saline technique given the shallow depth of the epidural space. Thoracic epidural catheters placed via the caudal route may reduce the risk of direct neural injury from needle placement, but often pose higher risks of infection and/or improper positioning if placed without radiographic guidance. We present a detailed method of placing a fluoroscopically guided, tunneled transcaudal epidural catheter, which may reduce both of these risks. The accuracy and precision of this technique often provides adequate analgesia to allow for opioid-free epidural infusions as well as significant reductions in systemic opioids through the perioperative period. Opioid-free analgesia using a regional anesthetic technique allows for earlier extubation and reduced perioperative sedation, which may have a less deleterious neurocognitive effect on the developing brain of the neonate.

Perfectionism and negative affect after repeated failure: Anxiety, depression, and anger

OpenAIRE

Stoeber, Joachim; Schneider, Natalia; Hussain, Rimi; Matthews, Kelly

2014-01-01

Perfectionists have shown increased negative affect after failure compared to nonperfectionists. However, little is known about how perfectionists react to repeated failure. This study investigated the effects of two forms of perfectionism--self-oriented perfectionism and socially prescribed perfectionism--on 100 university students’ reactions to repeated failure (versus repeated success) examining three negative emotions: anxiety, depression, and anger. Results showed that socially prescribe...

Fluoroscopically guided automated gun biopsy of chest lesions: diagnostic accuracy and complications

International Nuclear Information System (INIS)

Oh, Hee Sul; Han, Young Min; Choi, Ki Chul and others

1998-01-01

To determine the diagnostic accuracy and frequency of complications of fluoroscopyguided transthoracic needle biopsy, using an automated gun biopsy system. We retrospectively reviewed 86 patients who underwent automated gun biopsy between October 1995 and October 1996. An 18-gauge cutting needle was used in all cases. All biopsies were performed under fluoroscopic guidance by one interventional radiologist. Tissue sufficient for histologic diagnosis was obtained in 73 of 86 biopsies(84.9%). Fifty-six lesions were malignent and 30 were benign. Sensitivity and diagnostic accuracy for malignant lesions were 87.5% and 87.5%, respectively while cell type specificity in malignant diagnosis was 91.7%(11/12). Sensitivity and diagnostic accuracy for benign lesions were 80.0% and 73.3%, respectively. Postbioptic pneumothorax occurred in three of 86 biopsies(3.5%), one of which required placement of a chest tube. Automated gun biopsy is a simple, safe method for the diagnosis of focal chest lesions. An automated biopsy device offers high diagnostic accuracy in casis involving malignant and benign lesions of the chest, and is particularly useful for determining malignant cell type and specific diagnosis of benign lesions.=20

Variations of Patient Doses in Interventional Examinations at Different Angiographic Units

International Nuclear Information System (INIS)

Bor, Dogan; Toklu, Tuerkay; Olgar, Turan; Sancak, Tanzer; Cekirge, Saruhan; Onal, Baran; Bilgic, Sadik

2006-01-01

Purpose. We analyzed doses for various angiographic procedures using different X-ray systems in order to assess dose variations. Methods. Dose-area product (DAP), skin doses from thermoluminescent dosimeters and air kerma measurements of 308 patients (239 diagnostic and 69 interventional) were assessed for five different angiographic units. All fluoroscopic and radiographic exposure parameters were recorded online for single and multiprojection studies. Radiation outputs of each X-ray system were also measured for all the modes of exposure using standard protocols for such measurements. Results. In general, the complexity of the angiographic procedure was found to be the most important reason for high radiation doses. Skill of the radiologist, management of the exposure parameters and calibration of the system are the other factors to be considered. Lateral cerebral interventional studies carry the highest risk for deterministic effects on the lens of the eye. Effective doses were calculated from DAP measurements and maximum fatal cancer risk factors were found for carotid studies. Conclusions. Interventional radiologists should measure patient doses for their examinations. If there is a lack of necessary instrumentation for this purpose, then published dose reports should be used in order to predict the dose levels from some of the exposure parameters. Patient dose information should include not only the measured quantity but also the measured radiation output of the X-ray unit and exposure parameters used during radiographic and fluoroscopic exposures

Transbronchial lung biopsy without fluoroscopic guide in Tehran Imam Khomeini’s Hospital (1999

Directory of Open Access Journals (Sweden)

"Firoozbakhsh S

2002-08-01

Full Text Available Background: Transbronchial lung biopsy (TBLB is an attractive alternative to open lung biopsy as an initial diagnostic procedure for patients with diffuse parenchymal disease or localized densities beyond direct endoscopic vision. TBLB can be carried out safely without fluoroscopy in patients with diffuse lung disease. Since in our bronchoscopic department fluoroscopy is not available, we planned to evaluate the blind (without fluoroscopic guide TBLB being performed in our department to determine the success rate in obtaining lung tissue, the sensitivity of the procedure and the risk of complications. Materials and Methods: Sixty-Four TBLB were done in our department during a 6 month period (March-September 1999. Results: Lung tissue wasn’t detected in two (3.1 percent samples. Pathological results were helpful in 46 (71.9 percent cases. No evidence of hemoptysis was found after the procedure. Three (4.68 percent cases of pneumothorax was detected. Only one of them required chest tube (1.51 percent. Conclusion: We concluded that blind TBLB was successful in our department with rates of complications comparable to other approved centers.

Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions; Exposition der Augenlinse des Untersuchers und Effizienz der Strahlenschutzmittel bei fluoroskopischen Interventionen

Energy Technology Data Exchange (ETDEWEB)

Galster, M.; Adamus, R. [Klinikum Nuernberg-Nord, Nuernberg (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Guhl, C. [Klinikum Nuernberg (Germany). Inst. fuer Medizinische Physik; Uder, M. [Erlangen Univ. (Germany). Radiologisches Inst.

2013-05-15

Purpose: Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. Materials and Methods: A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. Results: The exposition of the lens of about 110 to 550 {mu}Sv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25 LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. Conclusion: The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. (orig.)

Quantification of the gravity-dependent change in the C-arm image center for image compensation in fluoroscopic spinal neuronavigation.

Science.gov (United States)

Hariri, S; Abbasi, H R; Chin, S; Steinberg, G; Shahidi, R

2001-01-01

In the quest to develop a viable, frameless spinal navigation system, many researchers are utilizing the C-arm fluoroscope. However, there is a significant problem with the C-arm that must be quantified: the gravity-dependent sag effect resulting from the geometry of the C-arm and aggravated by the inequity of weight at each end of the C-arm. This study quantified the C-arm sag effect, giving researchers the protocol and data needed to develop a program that accounts for this distortion. The development of spinal navigation algorithms that account for the C-arm sag effect should produce a more accurate spinal navigation system.

The effectiveness of eye-closure in repeated interviews

NARCIS (Netherlands)

Vredeveldt, A.; Baddeley, A.D.; Hitch, G.J.

2014-01-01

Purpose Closing the eyes during recall can help witnesses remember more about a witnessed event. This study examined the effectiveness of eye-closure in a repeated recall paradigm with immediate free recall followed 1 week later by both free and cued recall. We examined whether eye-closure was more

The repeatability of three diagnostic methods (visual using ICDAS II, laser fluorescence, and radiographic) for early caries detection

Science.gov (United States)

Sukmasari, S.; Lestari, W.; Ko, B. B.; Noh, Z.; Asmail, N.; Yaacob, N.

2017-08-01

Newly introduced ICDAS II as a visual method, laser fluorescence as another technique that have ability to quantify early mineral loss of tooth structure and intra oral radiograph, are methods can be used in the clinic. To provide standardization for comprehensive caries management at an early stage, all methods supposed to be tested between users. The objective of this research is to evaluate the repeatability of each system. It is a comparative cross sectional study using 100 extracted permanent teeth without obvious cavitation (premolar & molar) that were collected and stored in thymol solution. The teeth were embedded on the wax block and labeled with numbers. All 5 surfaces were examined by 5 examiners using visual (ICDAS II), laser fluorescence (LF) and radiographic examination. The data were then analyzed to measure intra and inter examiner repeatability using Cronbach’s alpha and inter-item correlation matrix. Intra-examiner repeatability for all examiners was >0.7. Chronbach’s a value for inter-examiner repeatability for ICDAS II was >0.8 on 3 surfaces except on buccal and lingual. LF exhibit repeatability of >0.8 on all surfaces. Radiograph shows a low value of inter examiner repeatability (students for inter-item correlation while the 2nd and 3rd reading of LF displays the best agreement. ICDAS II score favors more non-invasive treatment compared to LF. ICDAS II showed good repeatability except on buccal and lingual surfaces. In line with some of the previous study, ICDAS II is applicable for caries detection in daily clinical basis. Laser fluorescence exhibits the highest repeatability while the radiograph showed weak inter-examiner repeatability. Treatment decisions of ICDAS II propose more preventive treatment for early caries lesions compared to laser fluorescence.

Impact of Inclusion or Exclusion of Repeaters on Test Equating

Science.gov (United States)

Puhan, Gautam

2011-01-01

This study examined the effect of including or excluding repeaters on the equating process and results. New forms of two tests were equated to their respective old forms using either all examinees or only the first timer examinees in the new form sample. Results showed that for both tests used in this study, including or excluding repeaters in the…

Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures

Science.gov (United States)

Marshall, Emily L.; Borrego, David; Tran, Trung; Fudge, James C.; Bolch, Wesley E.

2018-03-01

Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient’s true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient

Fluoroscopic-guided primary single-step percutaneous gastrostomy. Initial results using the Freka {sup registered} GastroTube; Primaere einzeitige durchleuchtungsgesteuerte perkutane Gastrostomie (PG). Erste Ergebnisse mit dem Freka {sup registered} GastroTube

Energy Technology Data Exchange (ETDEWEB)

Hahne, J.D.; Schoennagel, B.P.; Arndt, C.; Bannas, P.; Koops, A.; Adam, G.; Habermann, C.R. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Zentrum fuer Radiologie; Herrmann, J. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Zentrum fuer Radiologie; Universitaetsklinikum Hamburg-Eppendorf (Germany). Abt. Paediatrische Radiologie

2011-07-15

Purpose: To determine the practicability and outcome of fluoroscopic-guided primary one-step treatment of percutaneous gastrostomy (PG) with the system Freka {sup registered} Gastro Tube (Fresenius Kabi, Germany). Materials and Methods: In 39 patients (mean age 62.7 {+-} 12.0 years), primary PG was performed based on clinical indication from August 2009 to April 2010. The intervention was performed by an experienced radiologist under aseptic conditions by direct puncture with Freka {sup registered} Gastro Tube under fluoroscopic guidance. The clinical data and outcome as well as any complications originated from the electronic archive of the University Medical Center Hamburg-Eppendorf. Results: The intervention was technically successful in all 39 patients. Within the mean follow-up time of 155.3 {+-} 73.6 days, 29 patients (74.4 %) did not experience complications. 10 patients (25.6 %) had to be revised. Complications manifested after a mean of 135.6 {+-} 61.2 days and mainly corresponded to accidental dislocation (50 %). One patient had to be surgically revised under suspicion of a malpositioned tube and suspected intestinal perforation. Clinically relevant wound infections were not detected. The total costs per patient were 553.17 Euro for our single-step treatment (OPS 5 - 431.x) vs. 963.69 Euro (OPS 5 - 431.x and OPS 8 - 123.0) for the recommended two-step treatment. Conclusion: Fluoroscopic-guided primary single-step treatment with Freka {sup registered} Gastro Tube system is feasible and not associated with an increased complication rate when compared to published literature applying a two-step treatment approach. Material costs as well as human and time resources could be significantly reduced using the single-step treatment. (orig.)

Measurement of patient skin absorbed dose in ablation of paroxysmal atrial fibrillation, and examination of treatment protocol

International Nuclear Information System (INIS)

Shohji, Tomokazu; Hiramatsu, Masaki; Hasome, Hideki

2005-01-01

The ablation for atrial fibrillation minute movement done in our hospital is 250 minutes or less, within an average time of 150 minutes during a fluoroscopic time of about 7 hours, with very large average inspection times numerical values. However, the skin-absorbed dose could be understood only from the numerical value of the area dosimeter. It was considered that the total dose that reached the threshold was sufficient, although radiation injury would not be reported from the ablation currently done at our hospital. Therefore, we aimed to examine the inspection protocol in this hospital, and to request the patient be given an inspection dose that was the average skin-absorbed dose by using the acryl board. The amount of a total dose for an inspection of 150 minutes of fluoroscopic time was about 2.7 Gy. Moreover, a value of 1.5 Gy was indicated in the hot spot as a result of repetition in some exposure fields. However, it was thought that the possibility of exceeding the threshold of 2 Gy depending on the inspection situation in the future and other factors was tolerable because these measurements were done so as not to overvalue it more than the necessary. (author)

Temporal Alcohol Availability Predicts First-Time Drunk Driving, but Not Repeat Offending

OpenAIRE

Schofield, Timothy P.; Denson, Thomas F.

2013-01-01

Alcohol availability has been linked to drunk driving, but research has not examined whether this relationship is the same for first-time and repeat offenses. We examined the relationship between the business hours of alcohol outlets licensed to serve alcohol for on-premises consumption and misdemeanor-level (first offense) and felony-level drunk driving (repeat offense) charges in New York State in 2009. Longer outlet business hours were associated with more misdemeanor drunk driving charges...

A study on radiographic repeat rate data of several hospitals in Jeddah

International Nuclear Information System (INIS)

Al-Malki, M.A.; Abulfaraj, W.H.; Bhuiyan, S.I.; Kinsara, A.A.

2003-01-01

Radiographic repeat rate data in diagnostic radiology in King Fahad Hospital (KFH), King Abdulaziz Hospital (KAH), and Maternity and Children Hospital (MCH) in Jeddah, Saudi Arabia, have been studied. The study provided valuable information to suggest preventive measures to reduce repeats. The variables included in the study are exposure techniques, examination types, total number of films used, number of films repeated, the film sizes, gender, the age groups of the patients, and reason for repetition. The total number of examinations in all three hospitals is 6001 using 8887 films on 5412 patients. The average repeat rate was 7.93%, where the individual hospital repeat rates were 9.57% in the MCH, 7.84% in KAH and 7.44% in KFH. The repeat rate for children and infants was found to be undesirable. The quality assurance (QA) programme can effectively reduce the unnecessary exposure and can identify the cause of the exposure. The overexposure, underexposure and position fault were the foremost contributors for repeats and constitute 32.91%, 28.94% and 22.98% of the total respectively. The QA study identified that human error and equipment malfunction are the major contributors to these causes of repeats. The highest repetition rate was for pelvis, 13.64%, followed by skull, 11.59%, and abdomen, 10.41%. It is estimated that the total area of wasted film in all three hospitals is 74.3 m 2 . As per the average repeat rate, the cost of repeat films in the entire kingdom per year has been projected to be about US$1.82 million (SR 6.83 million) in the government hospitals only. Based on the findings of this study a set of recommendations have been prescribed for the radiology department to reduce the repeat rate and to improve the safety culture. (author)

A study on radiographic repeat rate data of several hospitals in Jeddah

Energy Technology Data Exchange (ETDEWEB)

Al-Malki, M.A.; Abulfaraj, W.H.; Bhuiyan, S.I.; Kinsara, A.A

2003-07-01

Radiographic repeat rate data in diagnostic radiology in King Fahad Hospital (KFH), King Abdulaziz Hospital (KAH), and Maternity and Children Hospital (MCH) in Jeddah, Saudi Arabia, have been studied. The study provided valuable information to suggest preventive measures to reduce repeats. The variables included in the study are exposure techniques, examination types, total number of films used, number of films repeated, the film sizes, gender, the age groups of the patients, and reason for repetition. The total number of examinations in all three hospitals is 6001 using 8887 films on 5412 patients. The average repeat rate was 7.93%, where the individual hospital repeat rates were 9.57% in the MCH, 7.84% in KAH and 7.44% in KFH. The repeat rate for children and infants was found to be undesirable. The quality assurance (QA) programme can effectively reduce the unnecessary exposure and can identify the cause of the exposure. The overexposure, underexposure and position fault were the foremost contributors for repeats and constitute 32.91%, 28.94% and 22.98% of the total respectively. The QA study identified that human error and equipment malfunction are the major contributors to these causes of repeats. The highest repetition rate was for pelvis, 13.64%, followed by skull, 11.59%, and abdomen, 10.41%. It is estimated that the total area of wasted film in all three hospitals is 74.3 m{sup 2}. As per the average repeat rate, the cost of repeat films in the entire kingdom per year has been projected to be about US$1.82 million (SR 6.83 million) in the government hospitals only. Based on the findings of this study a set of recommendations have been prescribed for the radiology department to reduce the repeat rate and to improve the safety culture. (author)

Patient doses from fluoroscopically guided cardiac procedures in pediatrics

Science.gov (United States)

Martinez, L. C.; Vano, E.; Gutierrez, F.; Rodriguez, C.; Gilarranz, R.; Manzanas, M. J.

2007-08-01

Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for <1 year; 52 for 1-<5 years; 25 for 5-<10 years and 13 for 10-<16 years. Median values of KAP were 1.9, 2.9, 4.5 and 15.4 Gy cm2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers.

Esophageal achalasia : results of balloon dilation

Energy Technology Data Exchange (ETDEWEB)

Ki, Won Woo; Kang, Sung Gwon; Yoon, Kwon Ha; Kim, Nam Hyeon; Lee, Hyo Jeong; Yoon, Hyun Ki; Sung, Kyu Bo; Song, Ho Young [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of)

1996-08-01

To evaluate the clinical effectiveness of fluoroscopically guided balloon dilation in the treatment of esophageal achalasia. Under fluoroscopic guidance, 21 balloon dilation procedures were performed in 14 patients with achalasia. A balloon with a diameter of 20 mm was used for the initial attempt.If the patient tolerated this well, the procedure was repeated with a 10-20 mm balloon, placed alongside at the same session. If, however the patient complained of severe chest pain and/or a postprocedural esophagogram showed an improvement,the additional balloon was not used. For patients whose results were unsatisfactory, the dilation procedure was repeated at sessions three to seven days apart. Succesful dilation was achieved in 13 of 14 patients(92.9%), who needed a total of 20 sessions of balloon dilation, ranging from one to three sessions per patient(mean, 1.54 sessions). Esophageal rupture occured in one of 14 patients(7.1%) ; of the 13 patients who underwent a successful dilation procedure, 12(92.3%) were free of recurrent symptoms during the follow-up period of 1-56(mean, 18.5) months. The remaning patient(7.7%) had a recurrence seven months after dilation. Fluoroscopically guided balloon dilation seems to be safe and effective in the treatment of esophageal achalasia.

Esophageal achalasia : results of balloon dilation

International Nuclear Information System (INIS)

Ki, Won Woo; Kang, Sung Gwon; Yoon, Kwon Ha; Kim, Nam Hyeon; Lee, Hyo Jeong; Yoon, Hyun Ki; Sung, Kyu Bo; Song, Ho Young

1996-01-01

To evaluate the clinical effectiveness of fluoroscopically guided balloon dilation in the treatment of esophageal achalasia. Under fluoroscopic guidance, 21 balloon dilation procedures were performed in 14 patients with achalasia. A balloon with a diameter of 20 mm was used for the initial attempt.If the patient tolerated this well, the procedure was repeated with a 10-20 mm balloon, placed alongside at the same session. If, however the patient complained of severe chest pain and/or a postprocedural esophagogram showed an improvement,the additional balloon was not used. For patients whose results were unsatisfactory, the dilation procedure was repeated at sessions three to seven days apart. Succesful dilation was achieved in 13 of 14 patients(92.9%), who needed a total of 20 sessions of balloon dilation, ranging from one to three sessions per patient(mean, 1.54 sessions). Esophageal rupture occured in one of 14 patients(7.1%) ; of the 13 patients who underwent a successful dilation procedure, 12(92.3%) were free of recurrent symptoms during the follow-up period of 1-56(mean, 18.5) months. The remaning patient(7.7%) had a recurrence seven months after dilation. Fluoroscopically guided balloon dilation seems to be safe and effective in the treatment of esophageal achalasia

Contrast fluoroscopic evaluation of gastrointestinal transit times with and without the use of falconry hoods in red-tailed hawks (Buteo jamaicensis).

Science.gov (United States)

Doss, Grayson A; Williams, Jackie M; Mans, Christoph

2017-11-01

OBJECTIVE To evaluate gastrointestinal transit times in red-tailed hawks (Buteo jamaicensis) by use of contrast fluoroscopic imaging and investigate the effect of falconry hooding in these hawks on gastrointestinal transit time. DESIGN Prospective, randomized, blinded, complete crossover study. ANIMALS 9 healthy red-tailed hawks. PROCEDURES Hawks were gavage-fed a 30% weight-by-volume barium suspension (25 mL/kg [11.3 mL/lb]) into the crop. Fluoroscopic images were obtained at multiple time points after barium administration. Time to filling and emptying of various gastrointestinal tract organs and overall transit time were measured. The effect of hooding (hooded vs nonhooded) on these variables was assessed in a randomized complete crossover design. RESULTS In nonhooded birds, overall gastrointestinal transit time ranged from 30 to 180 minutes (mean ± SD, 100 ± 52 min). Time to complete crop emptying ranged from 30 to 180 minutes (83 ± 49 min). Contrast medium was present in the ventriculus in all birds within 5 minutes of administration and in the small intestines within 5 to 15 minutes (median, 5 min). Hooding of red-tailed hawks resulted in a significant delay of complete crop emptying (no hood, 83 ± 49 minutes; hood, 133 ± 48 minutes), but no significant effects of hooding were found on other measured variables. CONCLUSIONS AND CLINICAL RELEVANCE These results indicated that overall gastrointestinal transit times are faster in red-tailed hawks than has been reported for psittacines and that the use of a falconry hood in red-tailed hawks may result in delayed crop emptying. Hooding did not exert significant effects on overall gastrointestinal transit time in this raptorial species.

Proposed Optimal Fluoroscopic Targets for Cooled Radiofrequency Neurotomy of the Sacral Lateral Branches to Improve Clinical Outcomes: An Anatomical Study.

Science.gov (United States)

Stout, Alison; Dreyfuss, Paul; Swain, Nathan; Roberts, Shannon; Loh, Eldon; Agur, Anne

2017-11-23

Current sacroiliac joint (SIJ) cooled radiofrequency (RF) is based on fluoroscopic anatomy of lateral branches (LBs) in three specimens. Recent studies confirm significant variation in LB positions. To determine if common fluoroscopic needle placements for cooled SIJ RF are adequate to lesion all S1-3 LBs. If not, would different targets improve lesion accuracy? The LBs of 20 cadavers were dissected bilaterally (40 SIJs), and 26 G radiopaque wires were sutured to the LBs. With a 10-mm radius ruler centered at each foramen, standard targets were assessed, as judged by a clockface on the right, for S1 and S2 at 2:30, 4:00, and 5:30 positions and at S3 at 2:30 and 4:00. Mirror image targets were assessed on the left. Assuming an 8-mm lesion diameter, the percentage of LBs that would not be ablated for each level was determined. Imaging through the superior end plate of S1 was compared against segment specific (SS) imaging. Nine point four percent of LBs would not be ablated at S1 vs 0.99% at S2 vs 35% at S3, and 60% of the 40 SIJs would be completely denervated using current targets. SS imaging did not improve results. Alternate target locations could improve the miss rate to 2.8% at S1 and 0% at S3 and would ablate all LBs in 95% of SIJs. Using a conservative 8-mm lesion measurement, contemporary cooled RF needle targets are inadequate to lesion all target LBs. Modifications to current targets are recommended to increase the effectiveness of the procedure. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Learning With Repeated-Game Strategies

Directory of Open Access Journals (Sweden)

Christos A. Ioannou

2014-07-01

Full Text Available We use the self-tuning Experience Weighted Attraction model with repeated-game strategies as a computer testbed to examine the relative frequency, speed of convergence and progression of a set of repeated-game strategies in four symmetric 2x2 games: Prisoner's Dilemma, Battle of the Sexes, Stag-Hunt, and Chicken. In the Prisoner's Dilemma game, we fi□nd that the strategy with the most occurrences is the Grim-Trigger. In the Battle of the Sexes game, a cooperative pair that alternates between the two pure-strategy Nash equilibria emerges as the one with the most occurrences. In the Stag-Hunt and Chicken games, the Win-Stay, Lose-Shift and Grim-Trigger strategies are the ones with the most occurrences. Overall, the pairs that converged quickly ended up at the cooperative outcomes, whereas the ones that were extremely slow to reach convergence ended up at non-cooperative outcomes.

The Usefulness of Virtual Fluoroscopic Preprocedural Planning During Percutaneous Transhepatic Biliary Drainage

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Mitsuhiro, E-mail: kinoshita.3216@tokushima-u.ac.jp [Tokushima University Hospital, Department of Radiology (Diagnostic Radiology) (Japan); Shirono, Ryozo; Takechi, Katsuya [Tokushima Red Cross Hospital, Department of Radiology (Japan); Yonekura, Hironobu [Tokushima Red Cross Hospital, Department of Radiological Technology (Japan); Iwamoto, Seiji [Tokushima University Graduate School, Department of Radiology and Radiation Oncology, Institute of Biomedical Sciences (Japan); Shinya, Takayoshi [Tokushima University Hospital, Department of Radiology (Diagnostic Radiology) (Japan); Takao, Shoichiro [Tokushima University Graduate School of Health Science, Department of Diagnostic Radiology (Japan); Harada, Masafumi [Tokushima University Graduate School, Department of Radiology and Radiation Oncology, Institute of Biomedical Sciences (Japan)

2017-06-15

Purpose To retrospectively evaluate the usefulness of virtual fluoroscopic preprocedural planning (VFPP) in the percutaneous transhepatic biliary drainage (PTBD) procedure.Materials and MethodsTwenty-two patients who were treated by PTBD were included in this study. Twelve patients were treated using PTBD intraoperative referencing coronal computed tomography (CT) images (i.e., coronal CT group), and ten patients were treated using PTBD intraoperative referencing VFPP images (i.e., VFPP group). To analyze the effect of the intraoperative referencing VFPP image, the VFPP group was retrospectively compared with the coronal CT group.ResultsThe characteristics of both patient groups were not statistically significantly different. There were no significant differences in the targeted bile duct, diameter and depth of the target bile, breath-holding ability, number of targeted bile duct puncture attempts, change in the targeted bile duct, and exchange of the drainage catheter. However, the X-ray fluoroscopy time and the procedure time were significantly shorter in the VFPP group than in the coronal CT group (196 vs. 334 s, P < 0.05; and 16.0 vs. 27.2 min, P < 0.05).ConclusionIntraoperative referencing using the VFPP imaging in PTBD intuitively can be a useful tool for better localization of the guidewire in the bile duct and thereby shorten the X-ray fluoroscopy time and procedure time while minimizing radiation exposure and complications.

Repeat cesarean delivery: what indications are recorded in the medical chart?

Science.gov (United States)

Lydon-Rochelle, Mona T; Gardella, Carolyn; Cárdenas, Vicky; Easterling, Thomas R

2006-03-01

National surveillance estimates reported a troubling 63 percent decline in the rate of vaginal birth after cesarean delivery (VBAC) from 1996 (28.3%) to 2003 (10.6%), with subsequent rising rates of repeat cesarean delivery. The study objective was to examine patterns of documented indications for repeat cesarean delivery in women with and without labor. We conducted a population-based validation study of 19 nonfederal short-stay hospitals in Washington state. Of the 4,541 women who had live births in 2000, 11 percent (n = 493) had repeat cesarean without labor and 3 percent (n = 138) had repeat cesarean with labor. Incidence of medical conditions and pregnancy complications, patterns of documented indications for repeat cesarean delivery, and perioperative complications in relation to repeat cesarean delivery with and without labor were calculated. Of the 493 women who underwent a repeat cesarean delivery without labor, "elective"(36%) and "maternal request"(18%) were the most common indications. Indications for maternal medical conditions (3.0%) were uncommon. Among the 138 women with repeat cesarean delivery with labor, 60.1 percent had failure to progress, 24.6 percent a non-reassuring fetal heart rate, 8.0 percent cephalopelvic disproportion, and 7.2 percent maternal request during labor. Fetal indications were less common (5.8%). Breech, failed vacuum, abruptio placentae, maternal complications, and failed forceps were all indicated less than 5.0 percent. Women's perioperative complications did not vary significantly between women without and with labor. Regardless of a woman's labor status, nearly 10 percent of women with repeat cesarean delivery had no documented indication as to why a cesarean delivery was performed. "Elective" and "maternal request" were common indications among women undergoing repeat cesarean delivery without labor, and nearly 10 percent of women had undocumented indications for repeat cesarean delivery in their medical record

Effects of intra-operative fluoroscopic 3D-imaging on peri-operative imaging strategy in calcaneal fracture surgery.

Science.gov (United States)

Beerekamp, M S H; Backes, M; Schep, N W L; Ubbink, D T; Luitse, J S; Schepers, T; Goslings, J C

2017-12-01

Previous studies demonstrated that intra-operative fluoroscopic 3D-imaging (3D-imaging) in calcaneal fracture surgery is promising to prevent revision surgery and save costs. However, these studies limited their focus to corrections performed after 3D-imaging, thereby neglecting corrections after intra-operative fluoroscopic 2D-imaging (2D-imaging). The aim of this study was to assess the effects of additional 3D-imaging on intra-operative corrections, peri-operative imaging used, and patient-relevant outcomes compared to 2D-imaging alone. In this before-after study, data of adult patients who underwent open reduction and internal fixation (ORIF) of a calcaneal fracture between 2000 and 2014 in our level-I Trauma center were collected. 3D-imaging (BV Pulsera with 3D-RX, Philips Healthcare, Best, The Netherlands) was available as of 2007 at the surgeons' discretion. Patient and fracture characteristics, peri-operative imaging, intra-operative corrections and patient-relevant outcomes were collected from the hospital databases. Patients in whom additional 3D-imaging was applied were compared to those undergoing 2D-imaging alone. A total of 231 patients were included of whom 107 (46%) were operated with the use of 3D-imaging. No significant differences were found in baseline characteristics. The median duration of surgery was significantly longer when using 3D-imaging (2:08 vs. 1:54 h; p = 0.002). Corrections after additional 3D-imaging were performed in 53% of the patients. However, significantly fewer corrections were made after 2D-imaging when 3D-imaging was available (Risk difference (RD) -15%; 95% Confidence interval (CI) -29 to -2). Peri-operative imaging, besides intra-operative 3D-imaging, and patient-relevant outcomes were similar between groups. Intra-operative 3D-imaging provides additional information resulting in additional corrections. Moreover, 3D-imaging probably changed the surgeons' attitude to rely more on 3D-imaging, hence a 15%-decrease of

Contrast-enhanced MR angiography of the carotid artery using 3D time-resolved imaging of contrast kinetics. Comparison with real-time fluoroscopic triggered 3D-elliptical centric view ordering

International Nuclear Information System (INIS)

Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Sakurai, Yasuo; Ishiguchi, Tsuneo; Ishigaki, Takeo; Ichinose, Nobuyasu

2001-01-01

The purpose of this study was to evaluate contrast-enhanced MR angiography using the 3D time-resolved imaging of contrast kinetics technique (3D-TRICKS) by direct comparison with the fluoroscopic triggered 3D-elliptical centric view ordering (3D-ELLIP) technique. 3D-TRICKS and 3D-ELLIP were directly compared on a 1.5-Tesla MR unit using the same spatial resolution and matrix. In 3D-TRICKS, the central part of the k-space is updated more frequently than the peripheral part of the k-space, which is divided in the slice-encoding direction. The carotid arteries were imaged using 3D-TRICKS and 3D-ELLIP sequentially in 14 patients. Temporal resolution was 12 sec for 3D-ELLIP and 6 sec for 3D-TRICKS. The signal-to-noise ratio (S/N) of the common carotid artery was measured, and the quality of MIP images was then scored in terms of venous overlap and blurring of vessel contours. No significant difference in mean S/N was seen between the two methods. Significant venous overlap was not seen in any of the patients examined. Moderate blurring of vessel contours was noted on 3D-TRICKS in five patients and on 3D-ELLIP in four patients. Blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. However, qualitative analysis scores showed no significant differences. When the spatial resolution of the two methods was identical, the performance of 3D-TRICKS was found to be comparable in static visualization of the carotid arteries with 3D-ELLIP, although blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. 3D-TRICKS is a more robust technique than 3D-ELLIP, because 3D-ELLIP requires operator-dependent fluoroscopic triggering. Furthermore, 3D-TRICKS can achieve higher temporal resolution. For the spatial resolution employed in this study, 3D-TRICKS may be the method of choice. (author)

Layered Architectures for Quantum Computers and Quantum Repeaters

Science.gov (United States)

Jones, Nathan C.

This chapter examines how to organize quantum computers and repeaters using a systematic framework known as layered architecture, where machine control is organized in layers associated with specialized tasks. The framework is flexible and could be used for analysis and comparison of quantum information systems. To demonstrate the design principles in practice, we develop architectures for quantum computers and quantum repeaters based on optically controlled quantum dots, showing how a myriad of technologies must operate synchronously to achieve fault-tolerance. Optical control makes information processing in this system very fast, scalable to large problem sizes, and extendable to quantum communication.

Temporal alcohol availability predicts first-time drunk driving, but not repeat offending.

Science.gov (United States)

Schofield, Timothy P; Denson, Thomas F

2013-01-01

Alcohol availability has been linked to drunk driving, but research has not examined whether this relationship is the same for first-time and repeat offenses. We examined the relationship between the business hours of alcohol outlets licensed to serve alcohol for on-premises consumption and misdemeanor-level (first offense) and felony-level drunk driving (repeat offense) charges in New York State in 2009. Longer outlet business hours were associated with more misdemeanor drunk driving charges, but were not associated with felony drunk driving charges. The per capita density of on-premises alcohol outlets did not affect misdemeanor or felony drunk driving charges. The results suggest that temporal alcohol availability may be an impelling factor for first-time drunk driving, but other factors likely influence repeat drunk driving behaviors.

Temporal alcohol availability predicts first-time drunk driving, but not repeat offending.

Directory of Open Access Journals (Sweden)

Timothy P Schofield

Full Text Available Alcohol availability has been linked to drunk driving, but research has not examined whether this relationship is the same for first-time and repeat offenses. We examined the relationship between the business hours of alcohol outlets licensed to serve alcohol for on-premises consumption and misdemeanor-level (first offense and felony-level drunk driving (repeat offense charges in New York State in 2009. Longer outlet business hours were associated with more misdemeanor drunk driving charges, but were not associated with felony drunk driving charges. The per capita density of on-premises alcohol outlets did not affect misdemeanor or felony drunk driving charges. The results suggest that temporal alcohol availability may be an impelling factor for first-time drunk driving, but other factors likely influence repeat drunk driving behaviors.

Estimation of population doses from diagnostic medical examinations in Japan, 1974. III. Per caput mean marrow dose and leukemia significant dose

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Maruyama, T; Kumamoto, Y [National Inst. of Radiological Sciences, Chiba (Japan)

1976-03-01

The mean per capita marrow dose and leukemia-significant dose from radiographic and fluoroscopic examinations in Japan have been estimated based on a 1974 nation wide survey of randomly sampled hospitals and clinics. To determine the mean marrow dose to an individual from a certain exposure of a given type of examination, the active marrow in the whole body was divided into 119 parts for an adult and 103 for a child. Dosimetric points on which the individual marrow doses were determined were set up in the center of each marrow part. The individual marrow doses at the dosimetric points in the beams of practical diagnostic x-rays were calculated on the basis of the exposure data on the patients selected in the nation wide survey, using depth dose curves experimentally determined for diagnostic x-rays. The mean individual marrow dose was averaged over the active marrow by summing, for each dosimetric point, the product of the fraction of active marrow exposed and the individual marrow dose at the dosimetric point. The leukemia significant dose was calculated by adopting a weighting factor that is, a leukemia significant factor. The factor was determined from the shape of the time-incidence curve for radiation-induced leukemia from the Hiroshima A-bomb and from the survival statistics for the average population. The resultant mean per capita marrow dose from radiographic and fluoroscopic examination was 37.0 and 70.0 mrad/person/year, respectively, with a total of 107.05 mrad/person/year. The leukemia significant dose was 32.1 mrad/person/year for radiographic examination and 61.2 mrad/person/year, with a total of 93.3. These values were compared with those of 1960 and 1969.

Fluoroscopic position of the second-generation cryoballoon during ablation in the right superior pulmonary vein as a predictor of phrenic nerve injury.

Science.gov (United States)

Saitoh, Yukio; Ströker, Erwin; Irfan, Ghazala; Mugnai, Giacomo; Ciconte, Giuseppe; Hünük, Burak; Velagić, Vedran; Overeinder, Ingrid; Tanaka, Kaoru; Brugada, Pedro; de Asmundis, Carlo; Chierchia, Gian-Battista

2016-08-01

Phrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein isolation procedure using the second-generation cryoballoon (CB). Our objective was to analyse the correlation between the fluoroscopic position of the 28 mm CB during ablation in the right superior pulmonary vein (RSPV) and the occurrence of PNI. A total of 165 patients having undergone the large 28 mm CB ablation were retrospectively reviewed. Positioning of the CB relative to the cardiac silhouette was classified under fluoroscopic guidance in antero-posterior projection during RSPV ablation. Regarding the lower half of the balloon, CB positioning was defined as follows: (A) completely inside the cardiac shadow; (B1) Phrenic nerve injury occurred in 9.7% (16/165) during ablation in the RSPV. The occurrence of PNI was 0.9, 10.6, and 90.1% in positions A, B1, and B2, respectively (A vs. B1, P = 0.01; B1 vs. B2, P < 0.0001). Among other pre-procedural and procedural variables, the B2 position was the strongest independent determinant for predicting PNI at RSPV (P = 0.001, odds ratio: 119.9; 95% confidence interval: 11.6-1234.7) after multivariable analysis. The incidence of PNI at the RSPV significantly increased in case of more distal positioning of the CB relative to the cardiac shadow. This simple and straightforward intra-procedural indicator might prone the operators to attempt occluding the RPSV more proximally in order to avoid PNI. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Radiation dose and intra-articular access: comparison of the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections

Energy Technology Data Exchange (ETDEWEB)

Huang, Ambrose J.; Torriani, Martin; Bredella, Miriam A.; Chang, Connie Y.; Simeone, Frank J.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Balza, Rene [Centro Medico de Occidente, Department of Radiology, Maracaibo (Venezuela, Bolivarian Republic of)

2016-03-15

To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP). This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (μGy-m{sup 2}) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP). There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 μGy-m{sup 2} versus 13.5 ± 17.3 μGy-m{sup 2}, P = 0.006). Both injection approaches resulted in nearly 100 % rates of intra-articular needle placement, but the lateral mortise approach used approximately 40 % less fluoroscopy time and delivered 15 % lower radiation dose and DAP to the patient. (orig.)

Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK).

Science.gov (United States)

Telles, Rosa Weiss; Costa-Silva, Luciana; Machado, Luciana A C; Reis, Rodrigo Citton Padilha Dos; Barreto, Sandhi Maria

To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA) in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK). A test-retest design including 19 adults (38 knee images) was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD) values. Repeatability was assessed for IMD and joint space width (JSW) measured at three different locations. Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1mm) ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5mm and ≤1.7mm, respectively). Repeatability analyses yielded the following results: IMD [SD of mean difference=1.08; coefficient of variation (%CV)=54.68%; intraclass correlation coefficient (ICC) (95%CI)=0.59 (0.34-0.77)]; JSW [SD of mean difference=0.34-0.61; %CV=4.48%-9.80%; ICC (95%CI)=0.74 (0.55-0.85)-0.94 (0.87-0.97)]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK. Copyright © 2016. Published by Elsevier Editora Ltda.

Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK

Directory of Open Access Journals (Sweden)

Rosa Weiss Telles

Full Text Available Abstract Objective: To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK. Material and methods: A test–retest design including 19 adults (38 knee images was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD values. Repeatability was assessed for IMD and joint space width (JSW measured at three different locations. Results: Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1 mm ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5 mm and ≤1.7 mm, respectively. Repeatability analyses yielded the following results: IMD [SD of mean difference = 1.08; coefficient of variation (%CV = 54.68%; intraclass correlation coefficient (ICC (95%CI = 0.59 (0.34–0.77]; JSW [SD of mean difference = 0.34–0.61; %CV = 4.48%–9.80%; ICC (95%CI = 0.74 (0.55–0.85–0.94 (0.87–0.97]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Conclusions: Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10 mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK.

Psychological and physiological responses following repeated peer death.

Directory of Open Access Journals (Sweden)

Judith Pizarro Andersen

Full Text Available Undergraduates at a university in the United States were exposed - directly and indirectly - to 14 peer deaths during one academic year. We examined how individual and social factors were associated with psychological (e.g., anxiety, depression, somatization and physiological (i.e., cortisol distress responses following this unexpected and repeated experience with loss.Two to three months after the final peer death, respondents (N = 122, 61% female, 18-23 years, M = 20.13, SD = 1.14 reported prior adverse experiences, degree of closeness with the deceased, acute responses to the peer deaths, ongoing distress responses, social support, support seeking, and media viewing. A subset (n = 24 returned hair samples for evaluation of cortisol responses during the previous 3 months.Ongoing psychological distress was associated with a prior interpersonal trauma, b fewer social supports, and c media exposure to news of the deaths (p's25 p/mg compared to individuals with one or two prior bereavement experiences (who were, on average, within the normal range, 10 to 25 p/mg (p<.05. Only 8% of the sample utilized available university psychological or physical health resources and support groups.Limited research has examined the psychological and physiological impact of exposure to chronic, repeated peer loss, despite the fact that there are groups of individuals (e.g., police, military soldiers that routinely face such exposures. Prior adversity appears to play a role in shaping psychological and physiological responses to repeated loss. This topic warrants further research given the health implications of repeated loss for individuals in high-risk occupations and university settings.

Two cases of radiodermatitis following repeated PTCA

International Nuclear Information System (INIS)

Hayami, Makoto

1998-01-01

Percutaneous transluminal coronary angioplasty (PTCA) is the most important procedure for the treatment of ischemic cardiac diseases. Under fluoroscopic imaging, the equipment is guided into coronary arteries via femoral artery. Excessive dosis of X-rays, in rare cases, may be irradiated to the patients during this complicated procedure. Recently I have observed 2 patients who developed radiodermatitis following multiple PTCAs on the location of the tube. Sixty-four and 63-year-old patients, both males, have been suffered from severe ulcerative radiodermatitis after being exposed to PTCAs 5 and 8 times, respectively. Two published literatures of the radiodermatitis caused by PTCA were previously reported from Israel and France. However, to the best of my knowledge, no report on the above injury has ever been seen in our country. (author)

Do repeated rumble strip hits improve driver alertness?

NARCIS (Netherlands)

Watling, C.N.; Akerstedt, T.; Kecklund, L.G.; Anund, A.

2016-01-01

Driving while sleepy is associated with increased crash risk. Rumble strips are designed to alert a sleepy or inattentive driver when they deviate outside their driving lane. The current study sought to examine the effects of repeated rumble strip hits on levels of physiological and subjective

Potentials and limitations of histone repeat sequences for phylogenetic reconstruction of Sophophora.

Science.gov (United States)

Baldo, A M; Les, D H; Strausbaugh, L D

1999-11-01

Simplified DNA sequence acquisition has provided many new data sets that are useful for phylogenetic reconstruction, including single- and multiple-copy nuclear and organellar genes. Although transcribed regions receive much attention, nontranscribed regions have recently been added to the repertoire of sequences suitable for phylogenetic studies, especially for closely related taxa. We evaluated the efficacy of a small portion of the histone repeat for phylogenetic reconstruction among Drosophila species. Histone repeats in invertebrates offer distinct advantages similar to those of widely used ribosomal repeats. First, the units are tandemly repeated and undergo concerted evolution. Second, histone repeats include both highly conserved coding and variable intergenic regions. This composition facilitates application of "universal" primers spanning potentially informative sites. We examined a small region of the histone repeat, including the intergenic spacer segments of coding regions from the divergently transcribed H2A and H2B histone genes. The spacer (about 230 bp) exists as a mosaic with highly conserved functional motifs interspersed with rapidly diverging regions; the former aid in alignment of the spacer. There are no ambiguities in alignment of coding regions. Coding and noncoding regions were analyzed together and separately for phylogenetic information. Parsimony, distance, and maximum-likelihood methods successfully retrieve the corroborated phylogeny for the taxa examined. This study demonstrates the resolving power of a small histone region which may now be added to the growing collection of phylogenetically useful DNA sequences.

RNA FISH for detecting expanded repeats in human diseases.

Science.gov (United States)

Urbanek, Martyna O; Krzyzosiak, Wlodzimierz J

2016-04-01

RNA fluorescence in situ hybridization (FISH) is a widely used technique for detecting transcripts in fixed cells and tissues. Many variants of RNA FISH have been proposed to increase signal strength, resolution and target specificity. The current variants of this technique facilitate the detection of the subcellular localization of transcripts at a single molecule level. Among the applications of RNA FISH are studies on nuclear RNA foci in diseases resulting from the expansion of tri-, tetra-, penta- and hexanucleotide repeats present in different single genes. The partial or complete retention of mutant transcripts forming RNA aggregates within the nucleoplasm has been shown in multiple cellular disease models and in the tissues of patients affected with these atypical mutations. Relevant diseases include, among others, myotonic dystrophy type 1 (DM1) with CUG repeats, Huntington's disease (HD) and spinocerebellar ataxia type 3 (SCA3) with CAG repeats, fragile X-associated tremor/ataxia syndrome (FXTAS) with CGG repeats, myotonic dystrophy type 2 (DM2) with CCUG repeats, amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) with GGGGCC repeats and spinocerebellar ataxia type 32 (SCA32) with GGCCUG. In this article, we summarize the results obtained with FISH to examine RNA nuclear inclusions. We provide a detailed protocol for detecting RNAs containing expanded CAG and CUG repeats in different cellular models, including fibroblasts, lymphoblasts, induced pluripotent stem cells and murine and human neuronal progenitors. We also present the results of the first single-molecule FISH application in a cellular model of polyglutamine disease. Copyright © 2015 Elsevier Inc. All rights reserved.

A Unified Model for Repeating and Non-repeating Fast Radio Bursts

International Nuclear Information System (INIS)

Bagchi, Manjari

2017-01-01

The model that fast radio bursts (FRBs) are caused by plunges of asteroids onto neutron stars can explain both repeating and non-repeating bursts. If a neutron star passes through an asteroid belt around another star, there would be a series of bursts caused by a series of asteroid impacts. Moreover, the neutron star would cross the same belt repetitively if it were in a binary with the star hosting the asteroid belt, leading to a repeated series of bursts. I explore the properties of neutron star binaries that could lead to the only known repeating FRB so far (FRB121102). In this model, the next two epochs of bursts are expected around 2017 February 27 and 2017 December 18. On the other hand, if the asteroid belt is located around the neutron star itself, then a chance fall of an asteroid from that belt onto the neutron star would lead to a non-repeating burst. Even a neutron star grazing an asteroid belt can lead to a non-repeating burst caused by just one asteroid plunge during the grazing. This is possible even when the neutron star is in a binary with the asteroid-hosting star, if the belt and the neutron star orbit are non-coplanar.

A Unified Model for Repeating and Non-repeating Fast Radio Bursts

Energy Technology Data Exchange (ETDEWEB)

Bagchi, Manjari, E-mail: manjari@imsc.res.in [The Institute of Mathematical Sciences (IMSc-HBNI), 4th Cross Road, CIT Campus, Taramani, Chennai 600113 (India)

2017-04-01

The model that fast radio bursts (FRBs) are caused by plunges of asteroids onto neutron stars can explain both repeating and non-repeating bursts. If a neutron star passes through an asteroid belt around another star, there would be a series of bursts caused by a series of asteroid impacts. Moreover, the neutron star would cross the same belt repetitively if it were in a binary with the star hosting the asteroid belt, leading to a repeated series of bursts. I explore the properties of neutron star binaries that could lead to the only known repeating FRB so far (FRB121102). In this model, the next two epochs of bursts are expected around 2017 February 27 and 2017 December 18. On the other hand, if the asteroid belt is located around the neutron star itself, then a chance fall of an asteroid from that belt onto the neutron star would lead to a non-repeating burst. Even a neutron star grazing an asteroid belt can lead to a non-repeating burst caused by just one asteroid plunge during the grazing. This is possible even when the neutron star is in a binary with the asteroid-hosting star, if the belt and the neutron star orbit are non-coplanar.

Repeatability of Cryogenic Multilayer Insulation

Science.gov (United States)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-12-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

Exploring antecedents of consumer satisfaction and repeated search behavior on e-health information.

Science.gov (United States)

Lee, Yun Jung; Park, Jungkun; Widdows, Richard

2009-03-01

E-health information has become an important resource for people seeking health information. Even though many studies have been conducted to examine the quality of e-health information, only a few studies have explored the effects of the information seekers' motivations on the perceived quality of e-health information. There is even less information about repeated searches for e-health information after the users' initial experience of e-health information use. Using an online survey of information seekers, 252 e-health information users' responses were collected. The research examines the relationship among motivation, perceived quality, satisfaction, and intention to repeat-search e-health information. The results identify motivations to search e-health information and confirm the relationship among motivation, perceived quality dimensions, and satisfaction and intention to repeat searches for e-health information.

Overcoming fixation with repeated memory suppression.

Science.gov (United States)

Angello, Genna; Storm, Benjamin C; Smith, Steven M

2015-01-01

Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

Frequency of X-ray diagnostic examinations in Japan, 1986

International Nuclear Information System (INIS)

Maruyama, Takashi; Kumamoto, Yoshikazu; Nishizawa, Kanae; Noda, Yutaka; Iwai, Kazuo; Mase, Naomichi.

1993-01-01

This is the results of actural survey done during a period October 17-24, 1986. Questionnaire was sent to randomely selected 1596 hospitals throughout the country. Nine hundred and fifty-seven hospitals responded it, consisting of 30 with 1000 beds or more, 58 with 300-999 beds, 216 with 20-299 beds, 623 with 20 beds or less, and 30 other special hospitals. The annual number of diagnostic X-ray examinations was 497 millions and 100 thousands (261 millions and 300 thousands for men and 235 millions and 800 thousands for women), which was increased by approximately 50%, as compared with the figure in 1979. The number of X-rays per patient averaged 3.5, being almost equal to that in 1979. The total number of X-ray examinations per diagnosis was 141 millions and 500 thousands (75 millions for men and 66 millions and 500 thousands for women). This figure was also increased by approximately 50% as compared with 1979. The number of X-ray examinations per person of the population increased with advancing age; the average of X-ray examinations was approximately 4 once a year at the age of 40, approximately 8 twice a year at the age of 60, and approximately 10 three times a year at the age of 70. The annual number of fluoroscopic examinations was 25 millions and 290 thousands (14 millions and 510 thousands for men and 10 millions and 780 thousands for women). The number of X-ray examinations for pregnant women was 660 thousands. (N.K.)

Deployment Repeatability

Science.gov (United States)

2016-04-01

evaluating the deployment repeatability builds upon the testing or analysis of deployment kinematics (Chapter 6) and adds repetition. Introduction...material yield or failure during a test. For the purposes of this chapter, zero shift will refer to permanent changes in the structure, while reversible ...the content of other chapters in this book: Gravity Compensation (Chapter 4) and Deployment Kinematics and Dynamics (Chapter 6). Repeating the

Patient and staff doses and relationships between them in fluoroscopically guided procedures

International Nuclear Information System (INIS)

Avramova-Cholakova, S.; Christova-Popova, Y.; Sagorska, A.

2015-01-01

Full text: Medical exposure has the main contribution to man-made sources of exposures to the population in developed countries. Fluoroscopically guided procedures in interventional cardiology, gastroenterology, urology, orthopaedics and others may be related to high doses to both patients and staff. The main risk for both groups is the radiation carcinogenesis and it is increasing with dose. However deterministic effects are also possible: severe patient skin injuries occur sometimes. There are such cases in Bulgarian radiological practice. For the medical staff, involved in the procedures, radiation induced cataract is observed occasionally. Learning objective: In many cases there is direct correlation between patient and staff doses. Several simple rules must be observed in order to decrease exposure. Rules related to patient: Patient dose (dose-area product (DAP), fluoroscopy time, number of series,number of images) should be recorded for every patient; The patient should be positioned as far away as possible from the x-ray tube and as closer as possible to the image intensifier/digital image receptor; Fluoroscopy time should be minimized; Pulsed fluoroscopy with the lowest dose rate and the lowest frame rate providing acceptable image quality should be used; Different skin areas should be exposed in different projections; Oblique projections increase the dose - they should be avoided; Magnification also increases the dose several times and should be avoided; The acquisition mode should be avoided; it delivers dozens of times higher doses. Minimal number of frames and cine runs should be used. Use of “last image hold” is encouraged; The x-ray beam should be collimated to the area of interest. Rules related to staff: The staff receives scattered radiation from patient’s body. Every measure to decrease patient’s dose decreases staff dose as well; Every available protective device should be used (lead apron, thyroid collar, lead glasses, screens). They

Palliation of malignant gastric obstruction : fluoroscopic guided covered metallic stent placement

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Yong; Choi, Ki Chul; Lee, Soo Tak; Han, Hyun Young

2000-01-01

To demonstrate the feasibility and clinical efficacy of self-expanding, covered metallic stent placement for the palliative treatment of malignant gastric obstruction. Under fluoroscopic guidance, the placement of self-expanding, covered stents was attempted in 23 patients (age range, 31-78 years) with inoperable or recurrent gastric malignancies. All 23 suffered dysphagia and/or vomiting after the ingestion of soft foods, or swallowing difficulty. Three different types of self-expanding, covered metallic stents were used and in all patients, these were placed perorally using over the guide wire technique. Success was defined both technically and clinically. Stent placement was technically successful in 19 patients (82.6%) but because the guidewire failed to successfully negotiate the sites at which there was obstruction, was unsuccessful in four (17.4%). Stent placement was well tolerated in all patients except one, in whom an acutely angled efferent loop from remnant stomach was present. In this case, stent placement required a strong metallic guidewire. After placement, 17 of the 19 patients (89.5%) were able to ingest solid and/or soft foods without dysphagia and showed a markedly decreased incidence of vomiting. Two others showed some improvement in the frequency of vomiting but were able to ingest only a liquid diet. In one patient, the stent migrated two days after the procedure. During the follow-up period of 2-7 months (mean, 74 days), there were no clinically significant complications. For the short-term palliative treatment of patients with gastric inlet or outlet obstruction, the placement of self-expanding metallic stents has proven relatively easy and safe, as well as reasonably effective. (author)

Reconfigurable multiport EPON repeater

Science.gov (United States)

Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

2009-11-01

An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

The effectiveness of eye-closure in repeated interviews

OpenAIRE

Vredeveldt, A.; Baddeley, A.D.; Hitch, G.J.

2014-01-01

Purpose Closing the eyes during recall can help witnesses remember more about a witnessed event. This study examined the effectiveness of eye-closure in a repeated recall paradigm with immediate free recall followed 1 week later by both free and cued recall. We examined whether eye-closure was more or less effective during the second free-recall attempt compared with the first, whether eye-closure during the first recall attempt had an impact on subsequent free- and cued-recall performance, a...

Repeated oral administration of capsaicin increases anxiety-like ...

Indian Academy of Sciences (India)

This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy ...

Improvement of Repeated-Sprint Ability and Horizontal-Jumping Performance in Elite Young Basketball Players With Low-Volume Repeated-Maximal-Power Training.

Science.gov (United States)

Gonzalo-Skok, Oliver; Tous-Fajardo, Julio; Arjol-Serrano, José Luis; Suarez-Arrones, Luis; Casajús, José Antonio; Mendez-Villanueva, Alberto

2016-05-01

To examine the effects of a low-volume repeated-power-ability (RPA) training program on repeated-sprint and change-of- direction (COD) ability and functional jumping performance. Twenty-two male elite young basketball players (age 16.2 ± 1.2 y, height 190.0 ± 10.0 cm, body mass 82.9 ± 10.1 kg) were randomly assigned either to an RPA-training group (n = 11) or a control group (n = 11). RPA training consisted of leg-press exercise, twice a week for 6 wk, of 1 or 2 blocks of 5 sets × 5 repetitions with 20 s of passive recovery between sets and 3 min between blocks with the load that maximized power output. Before and after training, performance was assessed by a repeated-sprint-ability (RSA) test, a repeated-COD-ability test, a hop for distance, and a drop jump followed by tests of a double unilateral hop with the right and left legs. Within-group and between-groups differences showed substantial improvements in slowest (RSAs) and mean time (RSAm) on RSA; best, slowest and mean time on repeated-COD ability; and unilateral right and left hop in the RPA group in comparison with control. While best time on RSA showed no improvement in any group, there was a large relationship (r = .68, 90% CI .43;.84) between the relative decrement in RSAm and RSAs, suggesting better sprint maintenance with RPA training. The relative improvements in best and mean repeated-COD ability were very largely correlated (r = .89, 90% CI .77;.94). Six weeks of lowvolume (4-14 min/wk) RPA training improved several physical-fitness tests in basketball players.

Repeatability study of replicate crash tests: A signal analysis approach.

Science.gov (United States)

Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

2017-10-03

To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

Repeated passive stretching : Acute effect on the passive muscle moment and extensibility of short hamstrings

NARCIS (Netherlands)

Halbertsma, JPK; Mulder, [No Value; Goeken, LNH; Eisma, WH; Mulder, I.; Göeken, L.N.

Objective: To examine the response of short hamstring muscles to repeated passive stretching. Design: A repeated measures design. Setting: A university laboratory for human movement analysis in a department of rehabilitation. Subjects: Students (7 men, 10 women) from the Department of Human Movement

Poor methodological detail precludes experimental repeatability and hampers synthesis in ecology.

Science.gov (United States)

Haddaway, Neal R; Verhoeven, Jos T A

2015-10-01

Despite the scientific method's central tenets of reproducibility (the ability to obtain similar results when repeated) and repeatability (the ability to replicate an experiment based on methods described), published ecological research continues to fail to provide sufficient methodological detail to allow either repeatability of verification. Recent systematic reviews highlight the problem, with one example demonstrating that an average of 13% of studies per year (±8.0 [SD]) failed to report sample sizes. The problem affects the ability to verify the accuracy of any analysis, to repeat methods used, and to assimilate the study findings into powerful and useful meta-analyses. The problem is common in a variety of ecological topics examined to date, and despite previous calls for improved reporting and metadata archiving, which could indirectly alleviate the problem, there is no indication of an improvement in reporting standards over time. Here, we call on authors, editors, and peer reviewers to consider repeatability as a top priority when evaluating research manuscripts, bearing in mind that legacy and integration into the evidence base can drastically improve the impact of individual research reports.

Expansion of protein domain repeats.

Directory of Open Access Journals (Sweden)

Asa K Björklund

2006-08-01

Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

Patient radiation dose audits for fluoroscopically guided interventional procedures

International Nuclear Information System (INIS)

Balter, Stephen; Rosenstein, Marvin; Miller, Donald L.; Schueler, Beth; Spelic, David

2011-01-01

Purpose: Quality management for any use of medical x-ray imaging should include monitoring of radiation dose. Fluoroscopically guided interventional (FGI) procedures are inherently clinically variable and have the potential for inducing deterministic injuries in patients. The use of a conventional diagnostic reference level is not appropriate for FGI procedures. A similar but more detailed quality process for management of radiation dose in FGI procedures is described. Methods: A method that takes into account both the inherent variability of FGI procedures and the risk of deterministic injuries from these procedures is suggested. The substantial radiation dose level (SRDL) is an absolute action level (with regard to patient follow-up) below which skin injury is highly unlikely and above which skin injury is possible. The quality process for FGI procedures collects data from all instances of a given procedure from a number of facilities into an advisory data set (ADS). An individual facility collects a facility data set (FDS) comprised of all instances of the same procedure at that facility. The individual FDS is then compared to the multifacility ADS with regard to the overall shape of the dose distributions and the percent of instances in both the ADS and the FDS that exceed the SRDL. Results: Samples of an ADS and FDS for percutaneous coronary intervention, using the dose metric of reference air kerma (K a,r ) (i.e., the cumulative air kerma at the reference point), are used to illustrate the proposed quality process for FGI procedures. Investigation is warranted whenever the FDS is noticeably different from the ADS for the specific FGI procedure and particularly in two circumstances: (1) When the facility's local median K a,r exceeds the 75th percentile of the ADS and (2) when the percent of instances where K a,r exceeds the facility-selected SRDL is greater for the FDS than for the ADS. Conclusions: Analysis of the two data sets (ADS and FDS) and of the

The leucine-rich repeat structure.

Science.gov (United States)

Bella, J; Hindle, K L; McEwan, P A; Lovell, S C

2008-08-01

The leucine-rich repeat is a widespread structural motif of 20-30 amino acids with a characteristic repetitive sequence pattern rich in leucines. Leucine-rich repeat domains are built from tandems of two or more repeats and form curved solenoid structures that are particularly suitable for protein-protein interactions. Thousands of protein sequences containing leucine-rich repeats have been identified by automatic annotation methods. Three-dimensional structures of leucine-rich repeat domains determined to date reveal a degree of structural variability that translates into the considerable functional versatility of this protein superfamily. As the essential structural principles become well established, the leucine-rich repeat architecture is emerging as an attractive framework for structural prediction and protein engineering. This review presents an update of the current understanding of leucine-rich repeat structure at the primary, secondary, tertiary and quaternary levels and discusses specific examples from recently determined three-dimensional structures.

Children's Conceptions of Bullying and Repeated Conventional Transgressions: Moral, Conventional, Structuring and Personal-Choice Reasoning

Science.gov (United States)

Thornberg, Robert; Thornberg, Ulrika Birberg; Alamaa, Rebecca; Daud, Noor

2016-01-01

This study examined 307 elementary school children's judgements and reasoning about bullying and other repeated transgressions when school rules regulating these transgressions have been removed in hypothetical school situations. As expected, children judged bullying (repeated moral transgressions) as wrong independently of rules and as more wrong…

Fluoroscopically Guided Transcervical Fallopian Tube Recanalization of Post-Sterilization Reversal Mid-Tubal Obstructions

International Nuclear Information System (INIS)

Houston, J. Graeme; Anderson, David; Mills, John; Harrold, Anthony

2000-01-01

Purpose: To assess the technical success and early outcome of fluoroscopically guided transcervical fallopian tube recanalization (FTR) in mid-tubal occlusion following sterilization reversal surgery.Methods: From July 1995 to January 1998, patients with greater than 12 months secondary infertility underwent hysterosalpingography (HSG). FTR was performed in proximal or mid-tubal occlusion. Cases of FTR in mid-tubal occlusion were included in this study. Technical success (defined as complete tubal patency) using a standard guidewire and hydrophilic glidewire, the number of patients with at least one patent tube, and the intrauterine and ectopic pregnancy rates were determined.Results: Twenty-six infertile patients with previous sterilization reversal underwent HSG. Eight of 26 (31%) patients (mean age 32 years, range 23-37 years), had attempted FTR for mid-tubal occlusion at the site of surgical anastomosis. Fourteen tubes were attempted as there were two previous salpingectomies. Technical success was achieved in eight of 14 (57%) tubes attempted, resulting in five of eight (62%) patients having at least one patent tube. At follow-up (mean 18 months, range 12-28 months) in these five patients there was one intrauterine pregnancy. There were no ectopic pregnancies.Conclusions: FTR in mid-tubal obstruction in infertile patients following sterilization reversal surgery is technically feasible and may result in intrauterine pregnancy. In this small group there was a lower technical success rate and lower pregnancy rate than in unselected proximal tubal occlusion

Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

Science.gov (United States)

Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

2014-02-01

The Gd5Ge2Si2 alloy and the off-stoichiometric Ni50Mn35In15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd5Ge2Si2 and Ni50Mn35In15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

International Nuclear Information System (INIS)

Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

2014-01-01

The Gd 5 Ge 2 Si 2 alloy and the off-stoichiometric Ni 50 Mn 35 In 15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd 5 Ge 2 Si 2 and Ni 50 Mn 35 In 15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis

Characteristics of intergenerational contractions of the CTG repeat in myotonic dystropy

Energy Technology Data Exchange (ETDEWEB)

Ashizawa, T.; Anvret, M.; Grandell, U.; Baiget, M.; Cobo, A.M.; Barcelo, J.M.; Korneluk, R.G.; Dallapiccola, B.; Novelli, G.; Fenwick, R.G. Jr. (and others)

1994-03-01

In myotonic dystropy (DM), the size of a CTG repeat in the DM kinase gene generally increases in successive generations with clinical evidence of anticipation. However, there have also been cases with an intergenerational contraction of the repeat. The authors have examined 1,489 DM parent-offspring pairs, of which 95 (6.4%) showed such contractions in peripheral blood leukocytes (PBL). In 56 of th 95 pairs, clinical data allowed an analysis of their anticipation status. It is surprising that anticipation occurred in 27 (48%) of these 56 pairs, while none clearly showed a later onset of DM in the asymptomatic offspring. The contraction occurred in 76 (10%) of 753 paternal transmission and in 19 (3%) of 736 maternal transmissions. Anticipation was observed more frequently in maternal (85%) than in paternal (37%) transmissions (P<.001). The parental repeat size correlated with the size of intergenerational contraction (r[sup 2] = .50, P [much lt].001), and the slope of linear regression was steeper in paternal ([minus].62) than in maternal ([minus].30) transmissions (P [much lt].001). Sixteen DM parents had multiple DM offspring with the CTG repeat contractions. This frequency was higher than the frequency expected from the probability of the repeat contractions (6.4%) and the size of DM sib population (1.54 DM offspring per DM parent, in 968 DM parents). The authors conclude that (1) intergenerational contraction of the CTG repeat in leukocyte DNA frequently accompanies apparent anticipation, especially when DM is maternally transmitted, and (2) the paternal origin of the repeat and the presence of the repeat contraction in a sibling increase the probability of the CTG repeat contraction. 43 refs., 1 fig., 4 tabs.

All-photonic quantum repeaters

Science.gov (United States)

Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

2015-01-01

Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

Repeated swim stress alters brain benzodiazepine receptors measured in vivo

International Nuclear Information System (INIS)

Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

1989-01-01

The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of [ 3 H]Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in [14C]iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress [an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures], although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results

Repeated swim stress alters brain benzodiazepine receptors measured in vivo

Energy Technology Data Exchange (ETDEWEB)

Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

1989-06-01

The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

The value of the repeated examination of BRAF V600E mutation status in diagnostics of papillary thyroid cancer.

Science.gov (United States)

Beiša, Augustas; Beiša, Virgilijus; Stoškus, Mindaugas; Ostanevičiūtė, Elvyra; Griškevičius, Laimonas; Strupas, Kęstutis

2016-01-01

Nodular thyroid disease is one of the most frequently diagnosed pathologies of the adult population in iodine-deficient regions. Approximately 30% of thyroid aspirates are classified as nondiagnostic/unsatisfactory or indeterminate. However, patients with indeterminate cytology still undergo surgery. The object of this study was to determine the diagnostic value of re-examining the BRAF V600E mutation in papillary thyroid carcinoma patients. All patients underwent ultrasound guided fine-needle aspiration of a thyroid nodule. They were assigned to one of the four groups (indeterminate or positive for malignant cells) of the Bethesda System for Reporting Thyroid Cytopathology. Genetic investigation of the BRAF V600E mutation was performed for all of the fine-needle aspiration cytology specimens. All of the patients underwent surgery. Subsequently, histological investigation of the removed tissues was performed. Additional analysis of the BRAF V600E mutation from the histology specimen was then performed for the initially BRAF-negative cases. Two hundred and fourteen patients were involved in the study. One hundred and six (49.53%) patients were diagnosed with thyroid cancer. Of these 106 patients, 95 (89.62%) patients were diagnosed with papillary thyroid cancer. The BRAF V600E mutation was positive in 62 (65.26%) and negative in 33 (34.74%) histologically confirmed papillary thyroid cancer cases. After the genetic investigation, a total of 74 (77.89%) papillary thyroid cancer cases were positive for the BRAF V600E mutation and 21 (22.11%) were negative. Repeated examination of the BRAF V600E mutation status in the fine-needle aspiration may potentially increase the sensitivity of papillary thyroid cancer diagnostics.

The relationship of social support concept and repeat mammography among Iranian women.

Science.gov (United States)

Farhadifar, Fariba; Taymoori, Parvaneh; Bahrami, Mitra; Zarea, Shamsy

2015-10-24

Breast cancer ranks as the first most common cancer among the Iranian women. The regular repeat of mammography with 1-2 year intervals leads to the increased efficiency of early detection of breast cancer. The present study examined the predictors of repeat mammography. It was hypothesized that higher social support is connected with mammography repeat. A cross-sectional study was carried out among 400 women 50 years and older in Sanandaj, Iran. Data was collected by the questionnaire including information on socio demographical variables and measuring social support level. Data was analyzed by SPSS16 software. Multiple logistic regression was used to determine the predictive power of demographic variables and dimensions of social support for repeat mammography. Women aged 50-55 years had three times odds of repeat mammography compared to women aged 56-60 years) OR, 3.02). Married women had greater odds of repeat mammography compared to single women (P women with higher social support was 0.93 times greater than the women with lower social support (OR, 0.93; 95 % CI, 0.91-0.95; P women are less likely repeat mammography than other Asian women. Identifying the associations between perceived social support and repeat mammography may offer detailed information to allow for future study and guide the development of interventions not only for Iranian women but also for similar cultural that received pay too little attention to date in the breast cancer literature.

Construction of Subgame-Perfect Mixed Strategy Equilibria in Repeated Games

NARCIS (Netherlands)

Berg, Kimmo; Schoenmakers, Gijsbertus

2017-01-01

This paper examines how to construct subgame-perfect mixed-strategy equilibria in discounted repeated games with perfect monitoring.We introduce a relatively simple class of strategy profiles that are easy to compute and may give rise to a large set of equilibrium payoffs. These sets are called

Intra-rater repeatability of the Oxford foot model in healthy children in different stages of the foot roll over process during gait

DEFF Research Database (Denmark)

Curtis, D J; Bencke, J; Stebbins, J A

2009-01-01

BACKGROUND: The repeatability of the Oxford foot model has been reported, but possible variations in the repeatability during the foot roll over process have not been examined. The aim of this study was to determine the relative and absolute repeatability of the model for each stage of the foot...... roll over process during gait and to compare foot kinematic data from this study with that from another centre as a preliminary examination of the model's inter-centre repeatability and validity. METHOD: Eight healthy children were tested twice at the gait laboratory. Foot kinematics from this study...... were plotted against those from an earlier repeatability study and repeatability statistics calculated for the three rockers of stance phase and swing phase. RESULTS: Foot kinematics from this study and an earlier repeatability study produced similar kinematic patterns and joint angle ranges...

Peripheral Insertion of a Central Venous Access Device Under Fluoroscopic Guidance Using a Peripherally Accessed System (PAS) Port in the Forearm

International Nuclear Information System (INIS)

Hata, Yasuhiro; Morita, Sojiro; Morita, Yoshitaka; Awatani, Toshihide; Takasaki, Motohiro; Horimi, Tadashi; Ozawa, Zen

1998-01-01

Purpose: We describe the technique, efficacy, and complications of fluoroscopy-guided implantation of a central venous access device using a peripherally accessed system (PAS) port via the forearm. Methods: Beginning in July 1994, 105 central venous access devices were implanted in 104 patients for the long-term infusion of antibiotics or antineoplasmic agents, blood products, or parenteral nutrition. The devices was inserted under fluoroscopic guidance with real-time venography from a peripheral route. Results: All ports were successfully implanted. There were no procedure-related complications. No thrombosis or local infection was observed; however, in six patients catheter-related phlebitis occurred. Conclusion: Fluoroscopy-guided implantation of a central venous access device using a PAS port via the forearm is safe and efficacious, and injection of contrast medium through a peripheral IV catheter before introduction of the catheter helps to avoid catheter-related phlebitis

Heart failure re-admission: measuring the ever shortening gap between repeat heart failure hospitalizations.

Directory of Open Access Journals (Sweden)

Jeffrey A Bakal

Full Text Available Many quality-of-care and risk prediction metrics rely on time to first rehospitalization even though heart failure (HF patients may undergo several repeat hospitalizations. The aim of this study is to compare repeat hospitalization models. Using a population-based cohort of 40,667 patients, we examined both HF and all cause re-hospitalizations using up to five years of follow-up. Two models were examined: the gap-time model which estimates the adjusted time between hospitalizations and a multistate model which considered patients to be in one of four states; community-dwelling, in hospital for HF, in hospital for any reason, or dead. The transition probabilities and times were then modeled using patient characteristics and number of repeat hospitalizations. We found that during the five years of follow-up roughly half of the patients returned for a subsequent hospitalization for each repeat hospitalization. Additionally, we noted that the unadjusted time between hospitalizations was reduced ∼40% between each successive hospitalization. After adjustment each additional hospitalization was associated with a 28 day (95% CI: 22-35 reduction in time spent out of hospital. A similar pattern was seen when considering the four state model. A large proportion of patients had multiple repeat hospitalizations. Extending the gap between hospitalizations should be an important goal of treatment evaluation.

Estimation of population doses from diagnostic medical examinations in Japan, 1974. II. Estimation of genetically significant dose

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Maruyama, T; Kumamoto, Y [National Inst. of Radiological Sciences, Chiba (Japan)

1976-03-01

The genetically significant dose from radiographic and fluoroscopic examination in Japan has been estimated based on a 1974 nation wide survey of randomly sampled hospitals and clinics. The gonad dose during x-ray diagnosis was determined with an ionization chamber placed at the positions of ovary and testis in a Rando phantom. The instrumented phantom was irradiated with medical diagnostic x-rays on the basis of the exposure data on the patients selected in the nation wide survey. In the calculation of the genetically significant dose, the child expectancy of the patients that undergo each particular type of examination was assumed to be same as that of the general population. The resultant genetically significant dose was 11.1 and 5.43 mrad per person per year for radiography and fluoroscopy, respectively. These values were compared with those of 1960 and 1969. Though the number of examinations per year shows a yearly increase, the genetically significant dose is gradually on the decrease. This may be due to technical improvements in medical radiological practices.

78 FR 65594 - Vehicular Repeaters

Science.gov (United States)

2013-11-01

... coordinators estimate the effect on coordination fees? Does the supposed benefit that mobile repeater stations... allow the licensing and operation of vehicular repeater systems and other mobile repeaters by public... email: [email protected] or phone: 202-418- 0530 or TTY: 202-418-0432. For detailed instructions for...

Tevatron serial data repeater system

International Nuclear Information System (INIS)

Ducar, R.J.

1981-01-01

A ten megabit per second serial data repeater system has been developed for the 6.28km Tevatron accelerator. The repeaters are positioned at each of the thirty service buildings and accommodate control and abort system communications as well as distribution of the Tevatron time and energy clocks. The repeaters are transparent to the particular protocol of the transmissions. Serial data are encoded locally as unipolar two volt signals employing the self-clocking Manchester Bi-Phase code. The repeaters modulate the local signals to low-power bursts of 50 MHz rf carrier for the 260m transmission between service buildings. The repeaters also demodulate the transmission and restructure the data for local utilization. The employment of frequency discrimination techniques yields high immunity to the characteristic noise spectrum

Upper ankle joint space detection on low contrast intraoperative fluoroscopic C-arm projections

Science.gov (United States)

Thomas, Sarina; Schnetzke, Marc; Brehler, Michael; Swartman, Benedict; Vetter, Sven; Franke, Jochen; Grützner, Paul A.; Meinzer, Hans-Peter; Nolden, Marco

2017-03-01

Intraoperative mobile C-arm fluoroscopy is widely used for interventional verification in trauma surgery, high flexibility combined with low cost being the main advantages of the method. However, the lack of global device-to- patient orientation is challenging, when comparing the acquired data to other intrapatient datasets. In upper ankle joint fracture reduction accompanied with an unstable syndesmosis, a comparison to the unfractured contralateral site is helpful for verification of the reduction result. To reduce dose and operation time, our approach aims at the comparison of single projections of the unfractured ankle with volumetric images of the reduced fracture. For precise assessment, a pre-alignment of both datasets is a crucial step. We propose a contour extraction pipeline to estimate the joint space location for a prealignment of fluoroscopic C-arm projections containing the upper ankle joint. A quadtree-based hierarchical variance comparison extracts potential feature points and a Hough transform is applied to identify bone shaft lines together with the tibiotalar joint space. By using this information we can define the coarse orientation of the projections independent from the ankle pose during acquisition in order to align those images to the volume of the fractured ankle. The proposed method was evaluated on thirteen cadaveric datasets consisting of 100 projections each with manually adjusted image planes by three trauma surgeons. The results show that the method can be used to detect the joint space orientation. The correlation between angle deviation and anatomical projection direction gives valuable input on the acquisition direction for future clinical experiments.

Repeat Customer Success in Extension

Science.gov (United States)

Bess, Melissa M.; Traub, Sarah M.

2013-01-01

Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

Film repeats in radiology department

International Nuclear Information System (INIS)

Suwan, A. Z.; Al-Shakharah, A. I

1997-01-01

During a one year period, 4910 radiographs of 55780 films were repeated. The objective of our study was to analyse and to classify the causes in order to minimize the repeats, cut the expenses and to provide optimal radiographs for accurate diagnosis. Analysis of the different factors revealed that, 43.6% of film repeats in our service were due to faults in exposure factors, centering comprises 15.9% of the repeats, while too much collimation was responsible for 7.6% of these repeats. All of which can be decreased by awareness and programmed training of technicians. Film blurring caused by patient motion was also responsible for 4.9% for radiographs reexamination, which can be minimized by detailed explanation to the patient and providing the necessary privacy. Fogging of X-Ray films by improper storage or inadequate handling or processing faults were responsible for 14.5% in repeats in our study. Methods and criteria for proper storage and handling of films were discussed. Recommendation for using modern day-light and laser processor has been high lighted. Artefacts are noticeably high in our cases, due to spinal dresses and frequent usage of precious metals for c osmotic purposes in this part of the world. The repeated films comprise 8.8% of all films We conclude that, the main factor responsible for repeats of up to 81.6% of cases was the technologists, thus emphasizing the importance of adequate training of the technologists. (authors). 15 refs., 9 figs., 1 table

Visual attention to repeated print advertising : A test of scanpath theory

NARCIS (Netherlands)

Pieters, F.G.M.; Rosbergen, E.; Wedel, M.

1999-01-01

The authors examine consumers' visual attention during repeated exposures to print advertisements using eye-tracking methodology. The authors propose a statistical model comprising submodels for two key measures of visual attention to elements of the advertisement: attention duration and inter- and

Visual attention to repeated print advertising : A test of scanpath theory

NARCIS (Netherlands)

Pieters, F.G.M.; Rosbergen, E.; Wedel, M.

The authors examine consumers' visual attention during repeated exposures to print advertisements using eye-tracking methodology. The authors propose a statistical model comprising submodels for two key measures of visual attention to elements of the advertisement: attention duration and inter- and

Repeat migration and disappointment.

Science.gov (United States)

Grant, E K; Vanderkamp, J

1986-01-01

This article investigates the determinants of repeat migration among the 44 regions of Canada, using information from a large micro-database which spans the period 1968 to 1971. The explanation of repeat migration probabilities is a difficult task, and this attempt is only partly successful. May of the explanatory variables are not significant, and the overall explanatory power of the equations is not high. In the area of personal characteristics, the variables related to age, sex, and marital status are generally significant and with expected signs. The distance variable has a strongly positive effect on onward move probabilities. Variables related to prior migration experience have an important impact that differs between return and onward probabilities. In particular, the occurrence of prior moves has a striking effect on the probability of onward migration. The variable representing disappointment, or relative success of the initial move, plays a significant role in explaining repeat migration probabilities. The disappointment variable represents the ratio of actural versus expected wage income in the year after the initial move, and its effect on both repeat migration probabilities is always negative and almost always highly significant. The repeat probabilities diminish after a year's stay in the destination region, but disappointment in the most recent year still has a bearing on the delayed repeat probabilities. While the quantitative impact of the disappointment variable is not large, it is difficult to draw comparisons since similar estimates are not available elsewhere.

Real-time fluoroscopic needle guidance in the interventional radiology suite using navigational software for percutaneous bone biopsies in children

Energy Technology Data Exchange (ETDEWEB)

Shellikeri, Sphoorti; Srinivasan, Abhay; Krishnamurthy, Ganesh; Vatsky, Seth; Zhu, Xiaowei; Keller, Marc S.; Cahill, Anne Marie [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Setser, Randolph M. [Siemens Medical Solutions USA, Inc., Hoffman Estates, IL (United States); Hwang, Tiffany J. [University of Southern California, Keck School of Medicine, Los Angeles, CA (United States); Girard, Erin [Siemens Medical Solutions USA, Inc., Princeton, NJ (United States)

2017-07-15

Navigational software provides real-time fluoroscopic needle guidance for percutaneous procedures in the Interventional Radiology (IR) suite. We describe our experience with navigational software for pediatric percutaneous bone biopsies in the IR suite and compare technical success, diagnostic accuracy, radiation dose and procedure time with that of CT-guided biopsies. Pediatric bone biopsies performed using navigational software (Syngo iGuide, Siemens Healthcare) from 2011 to 2016 were prospectively included and anatomically matched CT-guided bone biopsies from 2008 to 2016 were retrospectively reviewed with institutional review board approval. C-arm CT protocols used for navigational software-assisted cases included institution-developed low-dose (0.1/0.17 μGy/projection), regular-dose (0.36 μGy/projection), or a combination of low-dose/regular-dose protocols. Estimated effective radiation dose and procedure times were compared between software-assisted and CT-guided biopsies. Twenty-six patients (15 male; mean age: 10 years) underwent software-assisted biopsies (15 pelvic, 7 lumbar and 4 lower extremity) and 33 patients (13 male; mean age: 9 years) underwent CT-guided biopsies (22 pelvic, 7 lumbar and 4 lower extremity). Both modality biopsies resulted in a 100% technical success rate. Twenty-five of 26 (96%) software-assisted and 29/33 (88%) CT-guided biopsies were diagnostic. Overall, the effective radiation dose was significantly lower in software-assisted than CT-guided cases (3.0±3.4 vs. 6.6±7.7 mSv, P=0.02). The effective dose difference was most dramatic in software-assisted cases using low-dose C-arm CT (1.2±1.8 vs. 6.6±7.7 mSv, P=0.001) or combined low-dose/regular-dose C-arm CT (1.9±2.4 vs. 6.6±7.7 mSv, P=0.04), whereas effective dose was comparable in software-assisted cases using regular-dose C-arm CT (6.0±3.5 vs. 6.6±7.7 mSv, P=0.7). Mean procedure time was significantly lower for software-assisted cases (91±54 vs. 141±68 min, P=0

Quantum repeated games revisited

International Nuclear Information System (INIS)

Frąckiewicz, Piotr

2012-01-01

We present a scheme for playing quantum repeated 2 × 2 games based on Marinatto and Weber’s approach to quantum games. As a potential application, we study the twice repeated Prisoner’s Dilemma game. We show that results not available in the classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games proposed by Iqbal and Toor. We point out the drawbacks that make their results unacceptable. (paper)

Fluoroscopically-Guided Posterior Approach for Shoulder Magnetic Resonance Arthrography: Comparison with Conventional Anterior Approach

International Nuclear Information System (INIS)

Yoo, Koun J.; Ha, Doo Hoe; Lee, Sang Min

2011-01-01

To prospectively evaluate the usefulness of the fluoroscopically-guided posterior approach compared with the anterior approach for shoulder magnetic resonance(MR) arthrography. Institutional review board approval and informed consent were obtained. Among 60 shoulder MR arthrographies performed on 59 patients with symptomatic shoulders, an intra-articular injection was performed (30 cases using the anterior approach and 30 using the posterior approach). Procedure-related pain was assessed by using a 5 score visual analogue scale (VAS). Depth of the puncture and standardized depth of puncture by body mass index (BMI) were recorded. The contrast leakage along the course of the puncture was evaluated by reviewing the MR. The statistical analyses included the Mann-Whitney U and Kruskal-Wallis test. There was no significant difference in VAS scores between the anterior and posterior groups (1.77 ± 1.10 vs. 1.80 ± 0.96). Depth of puncture and standardized depth of puncture by BMI were significantly shorter in the posterior group than those in the anterior group (4.4 ± 0.8 cm and 1.8 ± 0.3 cm vs. 6.6 ± 0.9 cm and 2.8 ± 0.4 cm, p < 0.001), respectively. The incidence of contrast leakage was more frequent in the posterior group (p = 0.003). The posterior approach will be useful in shoulder MR arthrography with a suspected anterior pathology, a postoperative follow-up study or obese patient.

Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

Energy Technology Data Exchange (ETDEWEB)

Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S. [University of Colorado School of Medicine, Department of Radiology, Aurora, CO (United States)

2018-01-15

To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

International Nuclear Information System (INIS)

Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S.

2018-01-01

To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

Repeatability and accuracy of reproductive tract scoring to determine pubertal status in beef heifers.

Science.gov (United States)

Rosenkrans, Kelly S; Hardin, David K

2003-03-01

The objective of this study was to compare the repeatability and accuracy of palpation per rectum to transrectal ultrasonography and serum progesterone concentrations for determining pubertal status in beef heifers. One hundred and seventy-four rectal examinations were performed on 29 predominantly Angus heifers by two veterinarians (A and B) and assigned individual reproductive tract scores (RTS) during monthly examinations over a 3-month period. Heifers were examined in the morning by both veterinarians, randomized, and re-examined in the afternoon. The size and location of ovarian structures of each heifer were determined by ultrasonography. Heifers with follicles >10mm in diameter or corpora lutea were classified as pubertal. Serum progesterone concentrations at the time of the examination and 10 days later were determined by radioimmunoassay and used to classify heifers as prepubertal (or=1 ng/ml). Kappa, which describes degree of agreement beyond chance, was used to determine repeatability of the RTS system. Multicategory Kappa for agreement was 0.64 within veterinarian, 0.46 between veterinarian, and 0.35 between palpation per rectum and transrectal ultrasonography. Sensitivity and specificity of palpation per rectum for diagnosis of pubertal status compared to serum progesterone levels were higher (82 and 69%, respectively) than sensitivity and specificity of ultrasonography (79 and 59%, respectively). This study validates the RTS system as a repeatable and accurate screening test to evaluate pubertal status in groups of heifers prior to the onset of the breeding season.

Closed reduction and fluoroscopic-assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats.

Science.gov (United States)

Boekhout-Ta, Christina L; Kim, Stanley E; Cross, Alan R; Evans, Richard; Pozzi, Antonio

2017-01-01

To report complications and clinical outcome of dogs and cats that underwent fluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. Retrospective study. Client-owned dogs (n = 37) and cats (n = 4). Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated. Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harris classification, preoperative and postoperative displacement), surgical information (implant size, surgical duration), and outcome assessment information (functional outcome, radiographic outcome, and complications). The majority of animals (92%) were classified as full functional outcome. No significant predictors of functional outcome were identified. The overall complication rate was 15% (n = 6). Elective pin removal rate was 41% (n = 17). Goniometry and limb circumference measurements of the affected and contralateral limbs were not significantly different in dogs for which measurements were obtained. Seventeen of 18 animals (16 dogs, 2 cats) measured had bone length changes on follow-up radiographs. FAPP is associated with an excellent functional outcome in a narrow selection of fracture configurations, specifically those with minimal displacement and for which anatomical alignment can be achieved with closed reduction. © 2016 The American College of Veterinary Surgeons.

Occupational exposures during abdominal fluoroscopically guided interventional procedures for different patient sizes - A Monte Carlo approach.

Science.gov (United States)

Santos, William S; Belinato, Walmir; Perini, Ana P; Caldas, Linda V E; Galeano, Diego C; Santos, Carla J; Neves, Lucio P

2018-01-01

In this study we evaluated the occupational exposures during an abdominal fluoroscopically guided interventional radiology procedure. We investigated the relation between the Body Mass Index (BMI), of the patient, and the conversion coefficient values (CC) for a set of dosimetric quantities, used to assess the exposure risks of medical radiation workers. The study was performed using a set of male and female virtual anthropomorphic phantoms, of different body weights and sizes. In addition to these phantoms, a female and a male phantom, named FASH3 and MASH3 (reference virtual anthropomorphic phantoms), were also used to represent the medical radiation workers. The CC values, obtained as a function of the dose area product, were calculated for 87 exposure scenarios. In each exposure scenario, three phantoms, implemented in the MCNPX 2.7.0 code, were simultaneously used. These phantoms were utilized to represent a patient and medical radiation workers. The results showed that increasing the BMI of the patient, adjusted for each patient protocol, the CC values for medical radiation workers decrease. It is important to note that these results were obtained with fixed exposure parameters. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

No impact of repeated extinction exposures on operant responding maintained by different reinforcer rates.

Science.gov (United States)

Bai, John Y H; Podlesnik, Christopher A

2017-05-01

Greater rates of intermittent reinforcement in the presence of discriminative stimuli generally produce greater resistance to extinction, consistent with predictions of behavioral momentum theory. Other studies reveal more rapid extinction with higher rates of reinforcers - the partial reinforcement extinction effect. Further, repeated extinction often produces more rapid decreases in operant responding due to learning a discrimination between training and extinction contingencies. The present study examined extinction repeatedly with training with different rates of intermittent reinforcement in a multiple schedule. We assessed whether repeated extinction would reverse the pattern of greater resistance to extinction with greater reinforcer rates. Counter to this prediction, resistance to extinction was consistently greater across twelve assessments of training followed by six successive sessions of extinction. Moreover, patterns of responding during extinction resembled those observed during satiation tests, which should not alter discrimination processes with repeated testing. These findings join others suggesting operant responding in extinction can be durable across repeated tests. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic Contributors to Intergenerational CAG Repeat Instability in Huntington's Disease Knock-In Mice.

Science.gov (United States)

Neto, João Luís; Lee, Jong-Min; Afridi, Ali; Gillis, Tammy; Guide, Jolene R; Dempsey, Stephani; Lager, Brenda; Alonso, Isabel; Wheeler, Vanessa C; Pinto, Ricardo Mouro

2017-02-01

Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in exon 1 of the HTT gene. Longer repeat sizes are associated with increased disease penetrance and earlier ages of onset. Intergenerationally unstable transmissions are common in HD families, partly underlying the genetic anticipation seen in this disorder. HD CAG knock-in mouse models also exhibit a propensity for intergenerational repeat size changes. In this work, we examine intergenerational instability of the CAG repeat in over 20,000 transmissions in the largest HD knock-in mouse model breeding datasets reported to date. We confirmed previous observations that parental sex drives the relative ratio of expansions and contractions. The large datasets further allowed us to distinguish effects of paternal CAG repeat length on the magnitude and frequency of expansions and contractions, as well as the identification of large repeat size jumps in the knock-in models. Distinct degrees of intergenerational instability were observed between knock-in mice of six background strains, indicating the occurrence of trans-acting genetic modifiers. We also found that lines harboring a neomycin resistance cassette upstream of Htt showed reduced expansion frequency, indicative of a contributing role for sequences in cis, with the expanded repeat as modifiers of intergenerational instability. These results provide a basis for further understanding of the mechanisms underlying intergenerational repeat instability. Copyright © 2017 by the Genetics Society of America.

Repeated Recall and PKM? Maintain Fear Memories in Juvenile Rats

Science.gov (United States)

Oliver, Chicora F.; Kabitzke, Patricia; Serrano, Peter; Egan, Laura J.; Barr, Gordon A.; Shair, Harry N.; Wiedenmayer, Christoph

2016-01-01

We examined the neural substrates of fear memory formation and maintenance when repeated recall was used to prevent forgetting in young animals. In contrast to adult rats, juveniles failed to show contextual fear responses at 4 d post-fear conditioning. Reconsolidation sessions 3 and 6 d after conditioning restored contextual fear responses in…

Near-Peer Teaching in Paramedic Education: A Repeated Measures Design

Science.gov (United States)

Williams, Brett; Nguyen, David

2017-01-01

The transition of the Australian paramedic discipline from vocation education and training to the higher education sector has seen a sharp rise in interest in near-peer teaching (NPT). The objective of this study was to examine satisfaction levels of NPT over one academic semester among undergraduate paramedic students. A repeated measured design…

Repeatability of visual acuity measurement.

Science.gov (United States)

Raasch, T W; Bailey, I L; Bullimore, M A

1998-05-01

This study investigates features of visual acuity chart design and acuity testing scoring methods which affect the validity and repeatability of visual acuity measurements. Visual acuity was measured using the Sloan and British Standard letter series, and Landolt rings. Identifiability of the different letters as a function of size was estimated, and expressed in the form of frequency-of-seeing curves. These functions were then used to simulate acuity measurements with a variety of chart designs and scoring criteria. Systematic relationships exist between chart design parameters and acuity score, and acuity score repeatability. In particular, an important feature of a chart, that largely determines the repeatability of visual acuity measurement, is the amount of size change attributed to each letter. The methods used to score visual acuity performance also affect repeatability. It is possible to evaluate acuity score validity and repeatability using the statistical principles discussed here.

Studies on Section XI ultrasonic repeatability

International Nuclear Information System (INIS)

Jamison, T.D.; McDearman, W.R.

1981-05-01

A block representative of a nuclear component has been welded containing intentional defects. Acoustic emission data taken during the welding correlate well with ultrasonic data. Repetitive ultrasonic examinations have been performed by skilled operators using a procedure based on that desribed in ASME Section XI. These examinations were performed by different examination teams using different ultrasonic equipment in such a manner that the effects on the repeatability of the ultrasonic test method caused by the operator and by the use of different equipment could be estimated. It was tentatively concluded that when considering a large number of inspections: (1) there is no significant difference in indication sizing between operators, and (2) there is a significant difference in amplitude and defect sizing when instruments having different, Code acceptable operating characteristics are used. It was determined that the Section XI sizing parameters follow a bivariate normal distribution. Data derived from ultrasonically and physically sizing indications in nuclear components during farication show that the Section XI technique tends to overestimate the size of the reflectors

Somatic mosaicism of androgen receptor CAG repeats in colorectal carcinoma epithelial cells from men.

Science.gov (United States)

Di Fabio, Francesco; Alvarado, Carlos; Gologan, Adrian; Youssef, Emad; Voda, Linda; Mitmaker, Elliot; Beitel, Lenore K; Gordon, Philip H; Trifiro, Mark

2009-06-01

The X-linked human androgen receptor gene (AR) contains an exonic polymorphic trinucleotide CAG. The length of this encoded CAG tract inversely affects AR transcriptional activity. Colorectal carcinoma is known to express the androgen receptor, but data on somatic CAG repeat lengths variations in malignant and normal epithelial cells are still sporadic. Using laser capture microdissection (LCM), epithelial cells from colorectal carcinoma and normal-appearing mucosa were collected from the fresh tissue of eight consecutive male patients undergoing surgery (mean age, 70 y; range, 54-82). DNA isolated from each LCM sample underwent subsequent PCR and DNA sequencing to precisely determine AR CAG repeat lengths and the presence of microsatellite instability (MSI). Different AR CAG repeat lengths were observed in colorectal carcinoma (ranging from 0 to 36 CAG repeats), mainly in the form of multiple shorter repeat lengths. This genetic heterogeneity (somatic mosaicism) was also found in normal-appearing colorectal mucosa. Half of the carcinoma cases examined tended to have a higher number of AR CAG repeat lengths with a wider range of repeat size variation compared to normal mucosa. MSI carcinomas tended to have longer median AR CAG repeat lengths (n = 17) compared to microsatellite stable carcinomas (n = 14), although the difference was not significant (P = 0.31, Mann-Whitney test). Multiple unique somatic mutations of the AR CAG repeats occur in colorectal mucosa and in carcinoma, predominantly resulting in shorter alleles. Colorectal epithelial cells carrying AR alleles with shorter CAG repeat lengths may be more androgen-sensitive and therefore have a growth advantage.

Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: a report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council.

Science.gov (United States)

Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

2012-05-01

Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology "automatic dose rate and image quality" (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

Energy Technology Data Exchange (ETDEWEB)

Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith [Henry Ford Health System, Detroit, Michigan 48202 (United States); Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115 (United States); Columbia University Medical Center, New York, New York 10032 (United States); Shiga Medical Center for Children, Moriyama City, Shiga-Ken, Japan 524-0022 (Japan); University of Virginia Health Science Center, Charlottesville, Virginia 22908 (United States); Baystate Health Systems, Inc., Springfield, Massachusetts 01199 (United States); Columbia University Medical Center, New York, New York 10032 (United States); University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Cincinnati Children' s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

2012-05-15

Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology ''automatic dose rate and image quality'' (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which

Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

International Nuclear Information System (INIS)

Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

2012-01-01

Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology ''automatic dose rate and image quality'' (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

Fostering repeat donations in Ghana.

Science.gov (United States)

Owusu-Ofori, S; Asenso-Mensah, K; Boateng, P; Sarkodie, F; Allain, J-P

2010-01-01

Most African countries are challenged in recruiting and retaining voluntary blood donors by cost and other complexities and in establishing and implementing national blood policies. The availability of replacement donors who are a cheaper source of blood has not enhanced repeat voluntary donor initiatives. An overview of activities for recruiting and retaining voluntary blood donors was carried out. Donor records from mobile sessions were reviewed from 2002 to 2008. A total of 71,701 blood donations; 45,515 (63.5%) being voluntary donations with 11,680 (25%) repeat donations were collected during the study period. Donations from schools and colleges contributed a steady 60% of total voluntary whilst radio station blood drives increased contribution from 10 to 27%. Though Muslim population is less than 20%, blood collection was above the 30-donation cost-effectiveness threshold with a repeat donation trend reaching 60%. In contrast Christian worshippers provided donations. Repeat donation trends amongst school donors and radio blood drives were 20% and 70% respectively. Repeat donations rates have been variable amongst different blood donor groups in Kumasi, Ghana. The impact of community leaders in propagating altruism cannot be overemphasized. Programs aiming at motivating replacement donors to be repeat donors should be developed and assessed. Copyright 2009 The International Association for Biologicals. All rights reserved.

Comparing Destination Image and Loyalty between First-time and Repeat-visit Tourists

Directory of Open Access Journals (Sweden)

Mohamad M.

2014-01-01

Full Text Available The objective of this study was to investigate the difference between destination image and loyalty among first-time and repeat-visit tourists. The study was undertaken to examine aspects of underlying factors of destination image that influenced tourists’ willingness to recommend Malaysia to their friends and relatives as well as spread positive word-of-mouth to others. In addition, it was to ascertain the relationship between destination image and loyalty among first-time and repeat-visit tourists. The data was collected at Kuala Lumpur International Airport at the departure hall using self-administered questionnaires. 248 usable questionnaires were returned and analysed. The findings of the study revealed that both groups of tourists perceived Malaysia as providing a nature-based destination. The study also empirically proved that both first-time and repeat-visit tourists were willing to disseminate positive word-of-mouth and recommend Malaysia to their friends and relatives as a vacation destination to visit. However, there was a significant difference in destination loyalty between first-visit and repeat-visit tourists.

Fluoroscopy without the grid: a method of reducing the radiation dose

International Nuclear Information System (INIS)

Drury, P.; Robinson, A.

1980-01-01

The anti-scatter grid has been removed from the fluoroscopic set during the course of over 80 contrast examinations performed routinely during the ordinary workload of a busy paediatric radiology department. This manoeuvre approximatley halves the radiation dose to the patient during both fluoroscopy and radiography. Experience suggests that the degree of loss of contrast consequent on the abandonment of the grid is diagnostically acceptable during many examinations performed on children (of all ages), when balanced against the lower radiation dose received. In addition, an assessment has been made of the contrast improvement factor of the grids in two fluoroscopic sets in common use, using tissue-equivalent phantoms of various thicknesses. Although the contrast was significantly improved by the use of the grid, to a degree dependent on various factors, the relevance of this improvement in clinical radiology depends on exactly what information is being sought. It is recommended that radiologists should use the grid with discretion when performing fluoroscopic examinations on children and that the apparatus for such examinations should have the capability for easy removal and reintroduction of the grid. (author)

Radiation brain dose to vascular surgeons during fluoroscopically guided interventions is not effectively reduced by wearing lead equivalent surgical caps.

Science.gov (United States)

Kirkwood, Melissa L; Arbique, Gary M; Guild, Jeffrey B; Zeng, Katie; Xi, Yin; Rectenwald, John; Anderson, Jon A; Timaran, Carlos

2018-03-12

Radiation to the interventionalist's brain during fluoroscopically guided interventions (FGIs) may increase the incidence of cerebral neoplasms. Lead equivalent surgical caps claim to reduce radiation brain doses by 50% to 95%. We sought to determine the efficacy of the RADPAD (Worldwide Innovations & Technologies, Lenexa, Kan) No Brainer surgical cap (0.06 mm lead equivalent at 90 kVp) in reducing radiation dose to the surgeon's and trainee's head during FGIs and to a phantom to determine relative brain dose reductions. Optically stimulated, luminescent nanoDot detectors (Landauer, Glenwood, Ill) inside and outside of the cap at the left temporal position were used to measure cap attenuation during FGIs. To check relative brain doses, nanoDot detectors were placed in 15 positions within an anthropomorphic head phantom (ATOM model 701; CIRS, Norfolk, Va). The phantom was positioned to represent a primary operator performing femoral access. Fluorography was performed on a plastic scatter phantom at 80 kVp for an exposure of 5 Gy reference air kerma with or without the hat. For each brain location, the percentage dose reduction with the hat was calculated. Means and standard errors were calculated using a pooled linear mixed model with repeated measurements. Anatomically similar locations were combined into five groups: upper brain, upper skull, midbrain, eyes, and left temporal position. This was a prospective, single-center study that included 29 endovascular aortic aneurysm procedures. The average procedure reference air kerma was 2.6 Gy. The hat attenuation at the temporal position for the attending physician and fellow was 60% ± 20% and 33% ± 36%, respectively. The equivalent phantom measurements demonstrated an attenuation of 71% ± 2.0% (P < .0001). In the interior phantom locations, attenuation was statistically significant for the skull (6% ± 1.4%) and upper brain (7.2% ± 1.0%; P < .0001) but not for the middle brain (1.4% ± 1.0%; P = .15

Topological characteristics of helical repeat proteins

NARCIS (Netherlands)

Groves, M R; Barford, D

The recent elucidation of protein structures based upon repeating amino acid motifs, including the armadillo motif, the HEAT motif and tetratricopeptide repeats, reveals that they belong to the class of helical repeat proteins. These proteins share the common property of being assembled from tandem

SU-G-BRA-05: Application of a Feature-Based Tracking Algorithm to KV X-Ray Fluoroscopic Images Toward Marker-Less Real-Time Tumor Tracking

Energy Technology Data Exchange (ETDEWEB)

Nakamura, M; Matsuo, Y; Mukumoto, N; Iizuka, Y; Yokota, K; Mizowaki, T; Hiraoka, M [Kyoto University, Graduate School of Medicine, Kyoto (Japan); Nakao, M [Kyoto University, Graduate School of Informatics, Kyoto (Japan)

2016-06-15

Purpose: To detect target position on kV X-ray fluoroscopic images using a feature-based tracking algorithm, Accelerated-KAZE (AKAZE), for markerless real-time tumor tracking (RTTT). Methods: Twelve lung cancer patients treated with RTTT on the Vero4DRT (Mitsubishi Heavy Industries, Japan, and Brainlab AG, Feldkirchen, Germany) were enrolled in this study. Respiratory tumor movement was greater than 10 mm. Three to five fiducial markers were implanted around the lung tumor transbronchially for each patient. Before beam delivery, external infrared (IR) markers and the fiducial markers were monitored for 20 to 40 s with the IR camera every 16.7 ms and with an orthogonal kV x-ray imaging subsystem every 80 or 160 ms, respectively. Target positions derived from the fiducial markers were determined on the orthogonal kV x-ray images, which were used as the ground truth in this study. Meanwhile, tracking positions were identified by AKAZE. Among a lot of feature points, AKAZE found high-quality feature points through sequential cross-check and distance-check between two consecutive images. Then, these 2D positional data were converted to the 3D positional data by a transformation matrix with a predefined calibration parameter. Root mean square error (RMSE) was calculated to evaluate the difference between 3D tracking and target positions. A total of 393 frames was analyzed. The experiment was conducted on a personal computer with 16 GB RAM, Intel Core i7-2600, 3.4 GHz processor. Results: Reproducibility of the target position during the same respiratory phase was 0.6 +/− 0.6 mm (range, 0.1–3.3 mm). Mean +/− SD of the RMSEs was 0.3 +/− 0.2 mm (range, 0.0–1.0 mm). Median computation time per frame was 179 msec (range, 154–247 msec). Conclusion: AKAZE successfully and quickly detected the target position on kV X-ray fluoroscopic images. Initial results indicate that the differences between 3D tracking and target position would be clinically acceptable.

SU-G-BRA-05: Application of a Feature-Based Tracking Algorithm to KV X-Ray Fluoroscopic Images Toward Marker-Less Real-Time Tumor Tracking

International Nuclear Information System (INIS)

Nakamura, M; Matsuo, Y; Mukumoto, N; Iizuka, Y; Yokota, K; Mizowaki, T; Hiraoka, M; Nakao, M

2016-01-01

Purpose: To detect target position on kV X-ray fluoroscopic images using a feature-based tracking algorithm, Accelerated-KAZE (AKAZE), for markerless real-time tumor tracking (RTTT). Methods: Twelve lung cancer patients treated with RTTT on the Vero4DRT (Mitsubishi Heavy Industries, Japan, and Brainlab AG, Feldkirchen, Germany) were enrolled in this study. Respiratory tumor movement was greater than 10 mm. Three to five fiducial markers were implanted around the lung tumor transbronchially for each patient. Before beam delivery, external infrared (IR) markers and the fiducial markers were monitored for 20 to 40 s with the IR camera every 16.7 ms and with an orthogonal kV x-ray imaging subsystem every 80 or 160 ms, respectively. Target positions derived from the fiducial markers were determined on the orthogonal kV x-ray images, which were used as the ground truth in this study. Meanwhile, tracking positions were identified by AKAZE. Among a lot of feature points, AKAZE found high-quality feature points through sequential cross-check and distance-check between two consecutive images. Then, these 2D positional data were converted to the 3D positional data by a transformation matrix with a predefined calibration parameter. Root mean square error (RMSE) was calculated to evaluate the difference between 3D tracking and target positions. A total of 393 frames was analyzed. The experiment was conducted on a personal computer with 16 GB RAM, Intel Core i7-2600, 3.4 GHz processor. Results: Reproducibility of the target position during the same respiratory phase was 0.6 +/− 0.6 mm (range, 0.1–3.3 mm). Mean +/− SD of the RMSEs was 0.3 +/− 0.2 mm (range, 0.0–1.0 mm). Median computation time per frame was 179 msec (range, 154–247 msec). Conclusion: AKAZE successfully and quickly detected the target position on kV X-ray fluoroscopic images. Initial results indicate that the differences between 3D tracking and target position would be clinically acceptable.

Repeatability and Reproducibility in Proteomic Identifications by Liquid Chromatography—Tandem Mass Spectrometry

Science.gov (United States)

Tabb, David L.; Vega-Montoto, Lorenzo; Rudnick, Paul A.; Variyath, Asokan Mulayath; Ham, Amy-Joan L.; Bunk, David M.; Kilpatrick, Lisa E.; Billheimer, Dean D.; Blackman, Ronald K.; Cardasis, Helene L.; Carr, Steven A.; Clauser, Karl R.; Jaffe, Jacob D.; Kowalski, Kevin A.; Neubert, Thomas A.; Regnier, Fred E.; Schilling, Birgit; Tegeler, Tony J.; Wang, Mu; Wang, Pei; Whiteaker, Jeffrey R.; Zimmerman, Lisa J.; Fisher, Susan J.; Gibson, Bradford W.; Kinsinger, Christopher R.; Mesri, Mehdi; Rodriguez, Henry; Stein, Steven E.; Tempst, Paul; Paulovich, Amanda G.; Liebler, Daniel C.; Spiegelman, Cliff

2009-01-01

The complexity of proteomic instrumentation for LC-MS/MS introduces many possible sources of variability. Data-dependent sampling of peptides constitutes a stochastic element at the heart of discovery proteomics. Although this variation impacts the identification of peptides, proteomic identifications are far from completely random. In this study, we analyzed interlaboratory data sets from the NCI Clinical Proteomic Technology Assessment for Cancer to examine repeatability and reproducibility in peptide and protein identifications. Included data spanned 144 LC-MS/MS experiments on four Thermo LTQ and four Orbitrap instruments. Samples included yeast lysate, the NCI-20 defined dynamic range protein mix, and the Sigma UPS 1 defined equimolar protein mix. Some of our findings reinforced conventional wisdom, such as repeatability and reproducibility being higher for proteins than for peptides. Most lessons from the data, however, were more subtle. Orbitraps proved capable of higher repeatability and reproducibility, but aberrant performance occasionally erased these gains. Even the simplest protein digestions yielded more peptide ions than LC-MS/MS could identify during a single experiment. We observed that peptide lists from pairs of technical replicates overlapped by 35–60%, giving a range for peptide-level repeatability in these experiments. Sample complexity did not appear to affect peptide identification repeatability, even as numbers of identified spectra changed by an order of magnitude. Statistical analysis of protein spectral counts revealed greater stability across technical replicates for Orbitraps, making them superior to LTQ instruments for biomarker candidate discovery. The most repeatable peptides were those corresponding to conventional tryptic cleavage sites, those that produced intense MS signals, and those that resulted from proteins generating many distinct peptides. Reproducibility among different instruments of the same type lagged behind

An examination of practice during radiography of the clavicle

International Nuclear Information System (INIS)

McEntee, Mark F.; Kinsella, Catherine

2010-01-01

Background: Variation in techniques is a well reported phenomenon in Radiography that can lead to dose discrepancies. Radiography of the clavicle is an examination which can result in a scattered extra-focal radiation dose to the radiosensitive organs of the thyroid, breast and eyes. Techniques for imaging the clavicle are examined and causal factors of repeats examined. Given the recent increase of the tissue weighting factor of breast tissue, an increased importance is placed upon dose reduction techniques to this area. Aims: This study aims to investigate the variation in techniques used in imaging of the clavicle and to investigate whether AP or PA position resulted in a higher level of repeat imaging. Method: To investigate current practice amongst hospitals a sample of large teaching hospitals was chosen (n = 5). An interview with radiographers was carried out along with an examination of the stated protocols in each of these hospital plus retrospective analysis of the images produced in each of these hospitals. Results: Variations in practice were established, significant differences in collimation and vertical centring were found. AP coned view of the clavicle was performed by 80% of radiographers interviewed with 20% of radiographers performing an AP shoulder. This variation being 100% correlated with country of training. 60% of radiographers were found to perform AP15 o cranial angulation clavicle as a second projection with 28%, 8% and 4% of those interview performing AP25 o , AP20 o , and AP30 o cranial angulation, respectively. The comparison of error and repeat rates study demonstrated a lack of confidence, reduced employment of collimation and reduced accuracy while centring in the PA position and it was deemed necessary to repeat in 30% of cases compared to 40% repeats were necessary. Conclusion: Wide variation exists in technique and PA imaging is not being implemented. The author recommends training and information on PA technique be disseminated

DNA Replication Dynamics of the GGGGCC Repeat of the C9orf72 Gene.

Science.gov (United States)

Thys, Ryan Griffin; Wang, Yuh-Hwa

2015-11-27

DNA has the ability to form a variety of secondary structures in addition to the normal B-form DNA, including hairpins and quadruplexes. These structures are implicated in a number of neurological diseases and cancer. Expansion of a GGGGCC repeat located at C9orf72 is associated with familial amyotrophic lateral sclerosis and frontotemporal dementia. This repeat expands from two to 24 copies in normal individuals to several hundreds or thousands of repeats in individuals with the disease. Biochemical studies have demonstrated that as little as four repeats have the ability to form a stable DNA secondary structure known as a G-quadruplex. Quadruplex structures have the ability to disrupt normal DNA processes such as DNA replication and transcription. Here we examine the role of GGGGCC repeat length and orientation on DNA replication using an SV40 replication system in human cells. Replication through GGGGCC repeats leads to a decrease in overall replication efficiency and an increase in instability in a length-dependent manner. Both repeat expansions and contractions are observed, and replication orientation is found to influence the propensity for expansions or contractions. The presence of replication stress, such as low-dose aphidicolin, diminishes replication efficiency but has no effect on instability. Two-dimensional gel electrophoresis analysis demonstrates a replication stall with as few as 20 GGGGCC repeats. These results suggest that replication of the GGGGCC repeat at C9orf72 is perturbed by the presence of expanded repeats, which has the potential to result in further expansion, leading to disease. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

UK 2009-2010 repeat station report

Directory of Open Access Journals (Sweden)

Thomas J.G. Shanahan

2013-03-01

Full Text Available The British Geological Survey is responsible for conducting the UK geomagnetic repeat station programme. Measurements made at the UK repeat station sites are used in conjunction with the three UK magnetic observatories: Hartland, Eskdalemuir and Lerwick, to produce a regional model of the local field each year. The UK network of repeat stations comprises 41 stations which are occupied at approximately 3-4 year intervals. Practices for conducting repeat station measurements continue to evolve as advances are made in survey instrumentation and as the usage of the data continues to change. Here, a summary of the 2009 and 2010 UK repeat station surveys is presented, highlighting the measurement process and techniques, density of network, reduction process and recent results.

Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

International Nuclear Information System (INIS)

Ling, B.C.; Lee, J.W.; Man, H.S.J.; Grace, M.G.A.; Lambert, R.G.W.; Jhangri, G.S.

2006-01-01

Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed. CT scans of pelvises were reformatted on 41 subjects, aged 51.7 (±15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 to +30 at 15 increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test. Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation

Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

Energy Technology Data Exchange (ETDEWEB)

Ling, B.C.; Lee, J.W.; Man, H.S.J.; Grace, M.G.A.; Lambert, R.G.W. [Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, Edmonton (Canada); Jhangri, G.S. [Department of Public Health Sciences, University of Alberta Hospital, Edmonton (Canada)

2006-11-15

Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed. CT scans of pelvises were reformatted on 41 subjects, aged 51.7 ({+-}15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 to +30 at 15 increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test. Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation.

Analysis of oligonucleotide array experiments with repeated measures using mixed models

Directory of Open Access Journals (Sweden)

Getchell Thomas V

2004-12-01

Full Text Available Abstract Background Two or more factor mixed factorial experiments are becoming increasingly common in microarray data analysis. In this case study, the two factors are presence (Patients with Alzheimer's disease or absence (Control of the disease, and brain regions including olfactory bulb (OB or cerebellum (CER. In the design considered in this manuscript, OB and CER are repeated measurements from the same subject and, hence, are correlated. It is critical to identify sources of variability in the analysis of oligonucleotide array experiments with repeated measures and correlations among data points have to be considered. In addition, multiple testing problems are more complicated in experiments with multi-level treatments or treatment combinations. Results In this study we adopted a linear mixed model to analyze oligonucleotide array experiments with repeated measures. We first construct a generalized F test to select differentially expressed genes. The Benjamini and Hochberg (BH procedure of controlling false discovery rate (FDR at 5% was applied to the P values of the generalized F test. For those genes with significant generalized F test, we then categorize them based on whether the interaction terms were significant or not at the α-level (αnew = 0.0033 determined by the FDR procedure. Since simple effects may be examined for the genes with significant interaction effect, we adopt the protected Fisher's least significant difference test (LSD procedure at the level of αnew to control the family-wise error rate (FWER for each gene examined. Conclusions A linear mixed model is appropriate for analysis of oligonucleotide array experiments with repeated measures. We constructed a generalized F test to select differentially expressed genes, and then applied a specific sequence of tests to identify factorial effects. This sequence of tests applied was designed to control for gene based FWER.

Repeated mild closed head injury impairs short-term visuospatial memory and complex learning.

Science.gov (United States)

Hylin, Michael J; Orsi, Sara A; Rozas, Natalia S; Hill, Julia L; Zhao, Jing; Redell, John B; Moore, Anthony N; Dash, Pramod K

2013-05-01

Concussive force can cause neurocognitive and neurobehavioral dysfunction by inducing functional, electrophysiological, and/or ultrastructural changes within the brain. Although concussion-triggered symptoms typically subside within days to weeks in most people, in 15%-20% of the cases, symptomology can continue beyond this time point. Problems with memory, attention, processing speed, and cognitive flexibility (e.g., problem solving, conflict resolution) are some of the prominent post-concussive cognitive symptoms. Repeated concussions (with loss or altered consciousness), which are common to many contact sports, can exacerbate these symptoms. The pathophysiology of repeated concussions is not well understood, nor is an effective treatment available. In order to facilitate drug discovery to treat post-concussive symptoms (PCSs), there is a need to determine if animal models of repeated mild closed head injury (mCHI) can mimic the neurocognitive and histopathological consequences of repeated concussions. To this end, we employed a controlled cortical impact (CCI) device to deliver a mCHI directly to the skull of mice daily for 4 days, and examined the ensuing neurological and neurocognitive functions using beam balance, foot-fault, an abbreviated Morris water maze test, context discrimination, and active place avoidance tasks. Repeated mCHI exacerbated vestibulomotor, motor, short-term memory and conflict learning impairments as compared to a single mCHI. Learning and memory impairments were still observed in repeated mCHI mice when tested 3 months post-injury. Repeated mCHI also reduced cerebral perfusion, prolonged the inflammatory response, and in some animals, caused hippocampal neuronal loss. Our results show that repeated mCHI can reproduce some of the deficits seen after repeated concussions in humans and may be suitable for drug discovery studies and translational research.

Effect of repeated burning on plant and soil carbon and nitrogen in cheatgrass (Bromus tectorum) dominated ecosystems

Science.gov (United States)

Rachel Jones; Jeanne C. Chambers; Dale W. Johnson; Robert R. Blank; David I. Board

2015-01-01

Fire has profound effects on ecosystem properties, but few studies have addressed the effect of repeated burns on soil nutrients, and none have been conducted in cold desert ecosystems where invasion by exotic annual grasses is resulting in greater fire frequency. In a 5 year study, we examined effects of repeated burning, litter removal, and post-fire seeding on...

Proportional lumbar spine inter-vertebral motion patterns: a comparison of patients with chronic, non-specific low back pain and healthy controls

OpenAIRE

Mellor, Fiona E.; Thomas, Peter; Thompson, Paul W.; Breen, Alan C.

2014-01-01

Introduction: Identifying biomechanical subgroups in chronic, non-specific low back pain (CNSLBP) populations from inter-vertebral displacements has proven elusive. Quantitative fluoroscopy (QF) has excellent repeatability and provides continuous standardised inter-vertebral kinematic data from fluoroscopic sequences allowing assessment of mid-range motion. The aim of this study was to determine whether proportional continuous IV rotational patterns were different in patients and controls. A ...

Radiation doses to patients in medical diagnostic x-ray examinations in New Zealand: a 1983-84 survey

International Nuclear Information System (INIS)

Williamson, B.D.P.; Poletti, J.L.; Cartwright, P.H.; Le Heron, J.C.

1993-06-01

A survey of doses to patients undergoing diagnostic x-ray examinations was performed in 1983-84. Developments since 1983-84 were reviewed and estimates made of the frequency of x-ray examinations, and doses to patients, as at 1992. The collective effective dose from general medical diagnostic radiology in 1983-84 was estimated to have been about 443 μSv per capita per annum. The figure excluded computed tomography which was estimated to have contributed about 5.6 μSv per capita per annum and mammography gave 0.3 μSv per annum. The total per capital effective dose from all medical diag over the whole period from 1983-84 to 1992. The highest dose examinations in 1983-84 were the fluoroscopic procedures barium enema and meal. Over the whole period 1983-84 to 1992 the genetically significant dose (GSD) to the population of New Zealand from medical diagnostic radiology was estimated to have been in the range 200-250 μSv per capita per annum. The two opposing tendencies noted for effective dose, viz, the fall in frequency of some examination types and the rise of Computed tomography, acted also upon this dose index. 43 refs., tabs., figs., ills

Repeating Marx

DEFF Research Database (Denmark)

Fuchs, Christian; Monticelli, Lara

2018-01-01

This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

Patient and staff doses in fluoroscopically guided invasive diagnostic and interventional urology procedures

International Nuclear Information System (INIS)

Ivanova, D.; Hristova-Popova, J.; Avramova-Cholakova, S.; Deyanova, Ts.; Dobrikov, R.

2015-01-01

Full text: The aim of this study is to evaluate patient and staff doses in fluoroscopically guided invasive diagnostic and interventional urology procedures. All the data were collected in the Emergency Hospital 'N. I. Pirogov'. While recording data for the patients, a real time dosimetry measurement of the medical staff was made. Air kerma-area product (KAP) was recorded for intravenous pyelogram (IVP), percutaneous nephrostomy (PN) and ureteral 'double-J' stenting. Patient data sex, age and weight were also taken. Staff doses were estimated with the system RaySafe i2. It contains four dosimeters, with a wireless connection to a real time display. The dosimeters were worn on the unprotected upper part of the body and measured the personal dose equivalent Hp(10). The mean KAP values for the procedures are: 3.21 Gy.cm 2 for IVP, 10.37 Gy.cm 2 for PN and 4.15 Gy.cm 2 for 'double-J' respectively. The highest staff dose for PN and 'double-J' is received by the urologist (160 μSv and 47.3 μSv, respectively), while for the IVP the radiographer has the highest exposure (20 μSv). Each member of the medical staff was on a different position in respect to the X-ray tube and the patient, which is the main reason for the differences in the staff doses. The variations in the mean patient and staff doses are mostly due to the interventions themselves, their complexity and the individual treatment of every patient. RaySafe i2 is very useful as guideline for making a choice of a better position and in the decreasing of radiation exposure to the staff

Examination of the effect of the annealing cation on higher order structures containing guanine or isoguanine repeats

Science.gov (United States)

Pierce, Sarah E.; Wang, Junmei; Jayawickramarajah, Janarthanan; Hamilton, Andrew D.; Brodbelt, Jennifer S.

2010-01-01

Isoguanine (2-oxo-6-amino-guanine), a natural but non-standard base, exhibits unique self-association properties compared to its isomer, guanine, and results in formation of different higher order DNA structures. In this work, the higher order structures formed by oligonucleotides containing guanine repeats or isoguanine repeats after annealing in solutions containing various cations are evaluated by electrospray ionization mass spectrometry (ESI-MS) and circular dichroism (CD) spectroscopy. The guanine-containing strand (G9) consistently formed quadruplexes upon annealing, whereas the isoguanine strand (Ig9) formed both pentaplexes and quadruplexes depending on the annealing cation. Quadruplex formation with G9 showed some dependence on the identity of the cation present during annealing with high relative quadruplex formation detected with six of ten cations. Analogous annealing experiments with Ig9 resulted in complex formation with all ten cations, and the majority of the resulting complexes were pentaplexes. CD results indicated most of the original complexes survived the desalting process necessary for ESI-MS analysis. In addition, several complexes, especially the pentaplexes, were found to be capable of cation exchange with ammonium ions. Ab initio calculations were conducted for isoguanine tetrads and pentads coordinated with all ten cations to predict the most energetically stable structures of the complexes in the gas phase. The observed preference of forming quadruplexes versus pentaplexes as a function of the coordinated cation can be interpreted by the calculated reaction energies of both the tetrads and pentads in combination with the distortion energies of tetrads. PMID:19746468

An Examination of Disciplinary Procedures with Children

Science.gov (United States)

Forehand, Rex; And Others

1976-01-01

Experiment 1 examined the effect of negative attention and repeated demands on the noncompliant behavior of children. Experiment 2 studied the relative effectiveness of negative attention, isolation, ignoring, and a combination of procedures in reducing noncompliance in children. (GO)

Entrance surface dose measurements in pediatric radiological examinations

International Nuclear Information System (INIS)

Ribeiro, L.A.; Yoshimura, E.M.

2008-01-01

A survey of pediatric radiological examinations was carried out in a reference pediatric hospital of the city of Sao Paulo, in order to investigate the doses to children undergoing conventional X-ray examinations. The results showed that the majority of pediatric patients are below 4 years, and that about 80% of the examinations correspond to chest projections. Doses to typical radiological examinations were measured in vivo with thermoluminescent dosimeters (LiF: Mg, Ti and LiF: Mg, Cu, P) attached to the skin of the children to determine entrance surface dose (ESD). Also homogeneous phantoms were used to obtain ESD to younger children, because the technique uses a so small kVp that the dosimeters would produce an artifact image in the patient radiograph. Four kinds of pediatric examinations were investigated: three conventional examinations (chest, skull and abdomen) and a fluoroscopic procedure (barium swallow). Relevant information about kVp and mAs values used in the examinations was collected, and we discuss how these parameters can affect the ESD. The ESD values measured in this work are compared to reference levels published by the European Commission for pediatric patients. The results obtained (third-quartile of the ESD distribution) for chest AP examinations in three age groups were: 0.056 mGy (2-4 years old); 0.068 mGy (5-9 years old); 0.069 mGy (10-15 years old). All of them are below the European reference level (0.100 mGy). ESD values measured to the older age group in skull and abdomen AP radiographs (mean values 3.44 and 1.20 mGy, respectively) are above the European reference levels (1.5 mGy to skull and 1.0 mGy to abdomen). ESD values measured in the barium swallow examination reached 10 mGy in skin regions corresponding to thyroid and esophagus. It was noticed during this survey that some technicians use, improperly, X-ray fluoroscopy in conventional examinations to help them in positioning the patient. The results presented here are a

Analysis of repeated measures data

CERN Document Server

Islam, M Ataharul

2017-01-01

This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

Genome-wide analysis of tandem repeats in plants and green algae

Science.gov (United States)

Zhixin Zhao; Cheng Guo; Sreeskandarajan Sutharzan; Pei Li; Craig Echt; Jie Zhang; Chun Liang

2014-01-01

Tandem repeats (TRs) extensively exist in the genomes of prokaryotes and eukaryotes. Based on the sequenced genomes and gene annotations of 31 plant and algal species in Phytozome version 8.0 (http://www.phytozome.net/), we examined TRs in a genome-wide scale, characterized their distributions and motif features, and explored their putative biological functions. Among...

Repeat-associated plasticity in the Helicobacter pylori RD gene family.

Science.gov (United States)

Shak, Joshua R; Dick, Jonathan J; Meinersmann, Richard J; Perez-Perez, Guillermo I; Blaser, Martin J

2009-11-01

The bacterium Helicobacter pylori is remarkable for its ability to persist in the human stomach for decades without provoking sterilizing immunity. Since repetitive DNA can facilitate adaptive genomic flexibility via increased recombination, insertion, and deletion, we searched the genomes of two H. pylori strains for nucleotide repeats. We discovered a family of genes with extensive repetitive DNA that we have termed the H. pylori RD gene family. Each gene of this family is composed of a conserved 3' region, a variable mid-region encoding 7 and 11 amino acid repeats, and a 5' region containing one of two possible alleles. Analysis of five complete genome sequences and PCR genotyping of 42 H. pylori strains revealed extensive variation between strains in the number, location, and arrangement of RD genes. Furthermore, examination of multiple strains isolated from a single subject's stomach revealed intrahost variation in repeat number and composition. Despite prior evidence that the protein products of this gene family are expressed at the bacterial cell surface, enzyme-linked immunosorbent assay and immunoblot studies revealed no consistent seroreactivity to a recombinant RD protein by H. pylori-positive hosts. The pattern of repeats uncovered in the RD gene family appears to reflect slipped-strand mispairing or domain duplication, allowing for redundancy and subsequent diversity in genotype and phenotype. This novel family of hypervariable genes with conserved, repetitive, and allelic domains may represent an important locus for understanding H. pylori persistence in its natural host.

Repeated irradiations with γ-rays at a dose of 0.5 Gy may exacerbate asthma

International Nuclear Information System (INIS)

Fang, Su-ping; Tago, Fumitoshi; Tanaka, Takashi; Simura, Noriko; Kojima, Shuji; Muto, Yasuko; Goto, Resuke

2005-01-01

We previously showed that 0.5 Gy whole-body γ-ray irradiation with a single or small number of repeated exposures inhibits tumor growth in mice, via elevation of the IFNγ/IL-4 ratio concomitantly with a decrease in the percentage of B cells. Here we examined whether repeated 0.5 Gy γ-rays irradiation can improve asthma in an ovalbumin (OVA)-induced asthmatic mouse model. We found that repeated irradiation (10 times) with 0.5 Gy of γ-rays significantly increased total IgE in comparison with the disease-control group. The levels of IL-4 and IL-5 were also significantly higher in the γ-ray-irradiated group, while that of IFN-γ was significantly lower, resulting in a further decrease of the IFN-γ/IL-4 ratio from the normal value. These results indicate that the repeated irradiation with γ-rays may exacerbate asthma, and may have opposite effects on different immune reactions unlike the irradiation with a single or small number of repeated exposures. (author)

Repeated Strains, Social Control, Social Learning, and Delinquency: Testing an Integrated Model of General Strain Theory in China

Science.gov (United States)

Bao, Wan-Ning; Haas, Ain; Chen, Xiaojin; Pi, Yijun

2014-01-01

In Agnew's general strain theory, repeated strains can generate crime and delinquency by reducing social control and fostering social learning of crime. Using a sample of 615 middle-and high-school students in China, this study examines how social control and social learning variables mediate the effect of repeated strains in school and at home on…

Repeated wildfires alter forest recovery of mixed-conifer ecosystems.

Science.gov (United States)

Stevens-Rumann, Camille; Morgan, Penelope

2016-09-01

Most models project warmer and drier climates that will contribute to larger and more frequent wildfires. However, it remains unknown how repeated wildfires alter post-fire successional patterns and forest structure. Here, we test the hypothesis that the number of wildfires, as well as the order and severity of wildfire events interact to alter forest structure and vegetation recovery and implications for vegetation management. In 2014, we examined forest structure, composition, and tree regeneration in stands that burned 1-18 yr before a subsequent 2007 wildfire. Three important findings emerged: (1) Repeatedly burned forests had 15% less woody surface fuels and 31% lower tree seedling densities compared with forests that only experienced one recent wildfire. These repeatedly burned areas are recovering differently than sites burned once, which may lead to alternative ecosystem structure. (2) Order of burn severity (high followed by low severity compared with low followed by high severity) did influence forest characteristics. When low burn severity followed high, forests had 60% lower canopy closure and total basal area with 92% fewer tree seedlings than when high burn severity followed low. (3) Time between fires had no effect on most variables measured following the second fire except large woody fuels, canopy closure and tree seedling density. We conclude that repeatedly burned areas meet many vegetation management objectives of reduced fuel loads and moderate tree seedling densities. These differences in forest structure, composition, and tree regeneration have implications not only for the trajectories of these forests, but may reduce fire intensity and burn severity of subsequent wildfires and may be used in conjunction with future fire suppression tactics. © 2016 by the Ecological Society of America.

Intraoperative CT in the assessment of posterior wall acetabular fracture stability.

Science.gov (United States)

Cunningham, Brian; Jackson, Kelly; Ortega, Gil

2014-04-01

Posterior wall acetabular fractures that involve 10% to 40% of the posterior wall may or may not require an open reduction and internal fixation. Dynamic stress examination of the acetabular fracture under fluoroscopy has been used as an intraoperative method to assess joint stability. The aim of this study was to demonstrate the value of intraoperative ISO computed tomography (CT) examination using the Siemens ISO-C imaging system (Siemens Corp, Malvern, Pennsylvania) in the assessment of posterior wall acetabular fracture stability during stress examination under anesthesia. In 5 posterior wall acetabular fractures, standard fluoroscopic images (including anteroposterior pelvis and Judet radiographs) with dynamic stress examinations were compared with the ISO-C CT imaging system to assess posterior wall fracture stability during stress examination. After review of standard intraoperative fluoroscopic images under dynamic stress examination, all 5 cases appeared to demonstrate posterior wall stability; however, when the intraoperative images from the ISO-C CT imaging system demonstrated that 1 case showed fracture instability of the posterior wall segment during stress examination, open reduction and internal fixation was performed. The use of intraoperative ISO CT imaging has shown an initial improvement in the surgeon's ability to assess the intraoperative stability of posterior wall acetabular fractures during stress examination when compared with standard fluoroscopic images. Copyright 2014, SLACK Incorporated.

simple sequence repeats (EST-SSR)

African Journals Online (AJOL)

Yomi

2012-01-19

Jan 19, 2012 ... 212 primer pairs selected, based on repeat patterns of n≥8 for di-, tri-, tetra- and penta-nucleotide repeat ... Cluster analysis revealed a high genetic similarity among the sugarcane (Saccharum spp.) breeding lines which could reduce the genetic gain in ..... The multiple allele characteristic of SSR com-.

Nifty Nines and Repeating Decimals

Science.gov (United States)

Brown, Scott A.

2016-01-01

The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

Repeated Prescribed Burning in Aspen

Science.gov (United States)

Donald A. Perala

1974-01-01

Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

Some anemonefish lack personality: a comparative assessment of behavioral variation and repeatability in relation to environmental and social factors

Science.gov (United States)

Wong, Marian Y. L.; Beasley, Amanda L.; Douglass, Tasman; Whalan, Steve; Scott, Anna

2017-12-01

Determining the extent of repeatable differences in the behavior of animals and the factors that influence behavioral expression is important for understanding individual fitness and population processes, thereby aiding in species conservation. However, little is known about the causes of variation in the repeatability of behavioral differences among species because rarely have comparative studies been undertaken to examine the repeatability of behavioral differences among individuals within their natural ecological settings. Using two species of endemic subtropical anemonefishes, Amphiprion mccullochi and A. latezonatus at Lord Howe and North Solitary Islands, Australia, we conducted an in situ comparative analysis of personality traits, examining the repeatability of boldness, sociability and aggression as well as the potential role of environmental and social factors on behavioral expression. For A. mccullochi, only boldness and aggression were highly repeatable and these behaviors formed a behavioral syndrome. For A. latezonatus, none of the three behaviors were repeatable due to low-inter-individual variation in behavior. We suggest that the harsher and more variable environmental and social conditions experienced by A. latezonatus have resulted in reduced repeatability in behavior, in contrast to A. mccullochi which typically inhabits a more stable lagoonal reef environment. Additionally, group size and size rank, rather than nearest-neighbor distance and anemone size, influenced the expression of these behaviors in both species, suggesting that behavioral variation was more sensitive to social than environmental factors. Overall, differences in repeatability between these closely related species likely reflect adaptations to contrasting environmental and social conditions, although alternative explanations must be considered. The differences in behavioral consistency between these two endemic anemonefishes could lead to disparity in their resilience to

Regret in repeat purchase versus switching decisions : The attenuating role of decision justifiability

NARCIS (Netherlands)

Inman, J.J.; Zeelenberg, M.

2002-01-01

The decision-making literature has consistently reported that decisions to maintain the status quo tend to be regretted less than decisions to change it. We examine the consequences of repeat purchasing (maintaining the status quo) versus switching in the context of information regarding the reason

Repeatability of measures of inflammatory cell number in bronchial biopsies in atopic asthma

NARCIS (Netherlands)

Sont, J. K.; Willems, L. N.; Evertse, C. E.; Hooijer, R.; Sterk, P. J.; van Krieken, J. H.

1997-01-01

Airway pathology is increasingly considered to be a major outcome in asthma research. The aim of this study was to examine the intra-observer, within-section and between-biopsy repeatability, together with the implications for statistical power of a computerized quantitative analysis of inflammatory

Overactive pelvic floor muscles (OPFM): improving diagnostic accuracy with clinical examination and functional studies.

Science.gov (United States)

Aw, Hau Choong; Ranasinghe, Weranja; Tan, Philip Huang Min; O'Connell, Helen E

2017-07-01

To identify the functional correlation of overactive pelvic floor muscles (OPFM) with cystoscopic and fluoroscopic urodynamic studies (FUDS), including urethral pressure measurements. Patients refractory to conservative therapy including bladder retraining, medications and pelvic muscle exercises for a variety of gamut of storage and voiding disorders were evaluated. Prospective data for 201 patients across both genders who underwent flexible cystoscopy and urodynamics for lower urinary tract symptoms (LUTS) refractory to conservative management between 01 Jan 2014 and 01 Jan 2016 was collected. Factors studied included history of LUTS, voiding patterns, physical examination, cystoscopic findings and functional studies, with maximum urethral closing pressure (MUCP). A total of 201 were patients recruited. The 85 were diagnosed with OPFM based on clinical presentation and presence of pelvic floor tenderness on examination. Significant differences were noted on functional studies with FUDS and urethral pressure measurement. Subjects with pelvic floor tenderness were found to have a higher (MUCP) at 93.1 cm H2O compared to 80.6 cm H2O (P=0.015). There are distinct characteristics of OPFM on clinical examination and functional studies, in particular MUCP. In patients refractory to conservative treatments, specific urodynamics tests are useful in sub-categorising patients. When OPFM is diagnosed, the impact on patient management is significant, and targeted intervention with pelvic floor physiotherapy is central in the multimodal approach of this complex condition.

The Enigma of Rapid Repeat Pregnancy: A Qualitative Study of Teen Mothers.

Science.gov (United States)

Conroy, K N; Engelhart, T G; Martins, Y; Huntington, N L; Snyder, A F; Coletti, K D; Cox, J E

2016-06-01

Rapid repeat pregnancy accounts for 18% of teen pregnancies and leads to adverse health, economic, and developmental outcomes for teen mothers and their children. Few interventions have been successful in reducing rapid repeat pregnancy. In this qualitative study we examined adolescent mothers' perceptions of their decision-making and behaviors that helped prevent or promote a rapid repeat pregnancy. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Semistructured interviews were conducted with 31 adolescent mothers, aged 16-21 years; 15 of these subjects experienced a repeat pregnancy within a year of their first child's birth and 16 had not. Two researchers used a grounded, inductive technique to identify emergent themes; interviews were subsequently coded accordingly. Counts were tabulated of the number of times themes were endorsed among those with or without a repeat pregnancy. Four overarching themes emerged from the interviews: intentionality regarding pregnancy planning, patients' degree of independence in making contraceptive choices, sense of control over life experience, and barriers to follow-through on contraceptive planning. Teens who had not experienced a rapid repeat pregnancy more often endorsed themes of intentionality in preventing or promoting a pregnancy, independence in decision-making, and feelings of control over their experience. Ambivalence and lack of decision-making about seeking another pregnancy were frequently endorsed by mothers who had experienced a second pregnancy. Decision-making regarding seeking or preventing a rapid repeat pregnancy is complex for teen mothers; techniques to help support decision-making or to delay pregnancy until decision-repeat making is complete might be important in reducing rapid pregnancy. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

Directory of Open Access Journals (Sweden)

Lawrence Paszat

2017-01-01

Full Text Available Background. The goal of this study is to examine utilization of early repeat colonoscopy ≤ 6 months after an index procedure. Methods. We identified persons having repeat colonoscopy ≤ 6 months following outpatient colonoscopy without prior colonoscopy ≤ 5 years or prior diagnosis of colorectal cancer (CRC. We modeled repeat colonoscopy using a generalized estimating equation with an exchangeable correlation structure to account for clustering of patients by endoscopist. Results. The population included 334,663 persons, 7,892 (2.36% of whom had an early repeat colonoscopy within 6 months. Overall, endoscopist prior year colonoscopy volume was inversely related to repeat ≤ 6 months. Repeat colonoscopy ≤ 6 months varied by the clinical setting of the index colonoscopy (adjusted OR = 1.41 (95% CI 1.29–1.55 at nonhospital facilities compared to teaching or community hospitals. Among those who had polypectomy or biopsy, the adjusted OR for early repeat ≤ 6 months was elevated among those whose index colonoscopy was at a nonhospital facility (OR 1.44, 95% CI 1.30–1.60, compared to those at a teaching hospital or community hospital. Conclusions. Repeat colonoscopy ≤ 6 months after an index procedure is associated with the clinical setting of the index colonoscopy.

Fixed-flexion radiography of the knee provides reproducible joint space width measurements in osteoarthritis

International Nuclear Information System (INIS)

Kothari, Manish; Sieffert, Martine; Block, Jon E.; Peterfy, Charles G.; Guermazi, Ali; Ingersleben, Gabriele von; Miaux, Yves; Stevens, Randall

2004-01-01

The validity of a non-fluoroscopic fixed-flexion radiographic acquisition and analysis protocol for measurement of joint space width (JSW) in knee osteoarthritis is determined. A cross-sectional study of 165 patients with documented knee osteoarthritis participating in a multicenter, prospective study of chondroprotective agents was performed. All patients had posteroanterior, weight-bearing, fixed-flexion radiography with 10 caudal beam angulation. A specially designed frame (SynaFlexer) was used to standardize the positioning. Minimum medial and lateral JSW were measured manually and twice by an automated analysis system to determine inter-technique and intra-reader concordance and reliability. A random subsample of 30 patients had repeat knee radiographs 2 weeks apart to estimate short-term reproducibility using automated analysis. Concordance between manual and automated medial JSW measurements was high (ICC=0.90); lateral compartment measurements showed somewhat less concordance (ICC=0.72). There was excellent concordance between repeated automated JSW measurements performed 6 months apart for the medial (ICC=0.94) and lateral (ICC=0.86) compartments. Short-term reproducibility for the subsample of 30 cases with repeat acquisitions demonstrated an average SD of 0.14 mm for medial JSW (CV=4.3%) and 0.23 mm for lateral JSW (CV=4.0%). Fixed-flexion radiography of the knee using a positioning device provides consistent, reliable and reproducible measurement of minimum JSW in knee osteoarthritis without the need for concurrent fluoroscopic guidance. (orig.)

Balloon dilation and airway stenting for benign and malignant tracheal stenosis

International Nuclear Information System (INIS)

Guo Jianhai; Yang Renjie; Zhang Hongzhi

2009-01-01

Objective: To assess the effectiveness of balloon dilation and airway stenting performed under fluoroscopic guidance for the treatment of benign and malignant tracheal stenosis. Methods: Under fluoroscopic guidance, balloon dilation and airway stenting were performed in 45 patients with tracheobronchial stricture. Of the 45 patients,malignant tracheal stenosis was seen in 37, including mediastinal nodal metastases (n=14), esophageal carcinoma (n=13), lung carcinoma (n= 4), adenocarcinoma of bronchus (n=3), lymphoma (n=2) and laryngocarcinoma (n=1), and benign tracheal stenosis was seen in 8, including endobronchial tuberculosis (n=6), retrosternal thyroid adenoma (n=1) and endotracheal intubation (n=1). Airway stenting with self-expandable metal stent was employed in 38 patients and balloon dilation in 7 patients. All the procedures were performed under fluoroscopic guidance. Results: A total of 53 self-expandable metal stents was implanted in 38 patients. The clinical symptoms were immediately relived after the procedure in all patients except for one patient who died from choking of sputum. No stent migration was observed. Restenosis developed in 4 patients, which was successfully treated with repeated stenting and balloon dilation. Nineteen times of balloon dilation procedure were accomplished in 7 patients. Marked remission of clinical symptoms was seen in most cases. During a follow-up period (ranged from 0 to 124 months with a mean of 24.5 months) 31 patients died. Conclusion: For both benign and malignant tracheal stenosis, balloon dilation with airway stenting performed under fluoroscopic guidance is a safe and efficient therapy with instant curative effect in relieving clinical symptoms. (authors)

The Pentapeptide Repeat Proteins

OpenAIRE

Vetting, Matthew W.; Hegde, Subray S.; Fajardo, J. Eduardo; Fiser, Andras; Roderick, Steven L.; Takiff, Howard E.; Blanchard, John S.

2006-01-01

The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S,T,A,V][D,N][L,F]-[S,T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Myc...

Microsatellite instability at a tetranucleotide repeat in type I endometrial carcinoma

Directory of Open Access Journals (Sweden)

Choi Ho

2008-12-01

Full Text Available Abstract Background Microsatellite instability (MSI at tri- or tetranucleotide repeat markers (elevated microsatellite alterations at selected tetranucleotide repeat, EMAST has been recently described. But, the underlying genetic mechanism of EMAST is unclear. This study was to investigate the prevalence of EMAST, in type I endometrial carcinoma, and to determine the correlation between the MSI status and mismatch repair genes (MMR or p53. Methods We examined the 3 mono-, 3 di-, and 6 tetranucleotide repeat markers by PCR in 39 cases of type I endometrial carcinoma and performed the immunohistochemistry of hMSH2, hMLH1, and p53 protein. Results More than two MSI at mono- and dinucleotide repeat markers was noted in 8 cases (MSI-H, 20.5%. MSI, at a tetranucleotide repeat, was detected in 15 cases (EMAST, 38.5%. In remaining 16 cases, any MSI was not observed. (MSS, 42.1%, MSI status was not associated with FIGO stage, grade or depth of invasion. The absence of expression of either one of both hMSH2 or hMLH1 was noted in seven (87.5% of eight MSI-H tumors, one (6.3% of 16 MSS tumors, and five (33.3% of 15 EMAST tumors. (p = 0.010 The expression of p53 protein was found in one (12.5% of eight MSI-H tumors, five (31.3% of 16 MSS tumors, and seven of 15 EMAST tumors. (p = 0.247 Conclusion Our results showed that about 38.5% of type I endometrial carcinomas exhibited EMAST, and that EMAST was rarely associated with alteration of hMSH2 or hMLH1.

Preservice science teachers' experiences with repeated, guided inquiry

Science.gov (United States)

Slack, Amy B.

The purpose of this study was to examine preservice science teachers' experiences with repeated scientific inquiry (SI) activities. The National Science Education Standards (National Research Council, 1996) stress students should understand and possess the abilities to do SI. For students to meet these standards, science teachers must understand and be able to perform SI; however, previous research demonstrated that many teachers have naive understandings in this area. Teacher preparation programs provide an opportunity to facilitate the development of inquiry understandings and abilities. In this study, preservice science teachers had experiences with two inquiry activities that were repeated three times each. The research questions for this study were (a) How do preservice science teachers' describe their experiences with repeated, guided inquiry activities? (b) What are preservice science teachers' understandings and abilities of SI? This study was conducted at a large, urban university in the southeastern United States. The 5 participants had bachelor's degrees in science and were enrolled in a graduate science education methods course. The researcher was one of the course instructors but did not lead the activities. Case study methodology was used. Data was collected from a demographic survey, an open-ended questionnaire with follow-up interviews, the researcher's observations, participants' lab notes, personal interviews, and participants' journals. Data were coded and analyzed through chronological data matrices to identify patterns in participants' experiences. The five domains identified in this study were understandings of SI, abilities to conduct SI, personal feelings about the experience, science content knowledge, and classroom implications. Through analysis of themes identified within each domain, the four conclusions made about these preservice teachers' experiences with SI were that the experience increased their abilities to conduct inquiry

In situ detection of tandem DNA repeat length

Energy Technology Data Exchange (ETDEWEB)

Yaar, R.; Szafranski, P.; Cantor, C.R.; Smith, C.L. [Boston Univ., MA (United States)

1996-11-01

A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats of known lengths. Single-stranded loop structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase. 7 refs., 4 figs.

Automated genotyping of dinucleotide repeat markers

Energy Technology Data Exchange (ETDEWEB)

Perlin, M.W.; Hoffman, E.P. [Carnegie Mellon Univ., Pittsburgh, PA (United States)]|[Univ. of Pittsburgh, PA (United States)

1994-09-01

The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

Repeat-Associated Plasticity in the Helicobacter pylori RD Gene Family▿ †

Science.gov (United States)

Shak, Joshua R.; Dick, Jonathan J.; Meinersmann, Richard J.; Perez-Perez, Guillermo I.; Blaser, Martin J.

2009-01-01

The bacterium Helicobacter pylori is remarkable for its ability to persist in the human stomach for decades without provoking sterilizing immunity. Since repetitive DNA can facilitate adaptive genomic flexibility via increased recombination, insertion, and deletion, we searched the genomes of two H. pylori strains for nucleotide repeats. We discovered a family of genes with extensive repetitive DNA that we have termed the H. pylori RD gene family. Each gene of this family is composed of a conserved 3′ region, a variable mid-region encoding 7 and 11 amino acid repeats, and a 5′ region containing one of two possible alleles. Analysis of five complete genome sequences and PCR genotyping of 42 H. pylori strains revealed extensive variation between strains in the number, location, and arrangement of RD genes. Furthermore, examination of multiple strains isolated from a single subject's stomach revealed intrahost variation in repeat number and composition. Despite prior evidence that the protein products of this gene family are expressed at the bacterial cell surface, enzyme-linked immunosorbent assay and immunoblot studies revealed no consistent seroreactivity to a recombinant RD protein by H. pylori-positive hosts. The pattern of repeats uncovered in the RD gene family appears to reflect slipped-strand mispairing or domain duplication, allowing for redundancy and subsequent diversity in genotype and phenotype. This novel family of hypervariable genes with conserved, repetitive, and allelic domains may represent an important locus for understanding H. pylori persistence in its natural host. PMID:19749042

Intraoperative mapping during repeat awake craniotomy reveals the functional plasticity of adult cortex.

Science.gov (United States)

Southwell, Derek G; Hervey-Jumper, Shawn L; Perry, David W; Berger, Mitchel S

2016-05-01

OBJECT To avoid iatrogenic injury during the removal of intrinsic cerebral neoplasms such as gliomas, direct electrical stimulation (DES) is used to identify cortical and subcortical white matter pathways critical for language, motor, and sensory function. When a patient undergoes more than 1 brain tumor resection as in the case of tumor recurrence, the use of DES provides an unusual opportunity to examine brain plasticity in the setting of neurological disease. METHODS The authors examined 561 consecutive cases in which patients underwent DES mapping during surgery forglioma resection. "Positive" and "negative" sites-discrete cortical regions where electrical stimulation did (positive) or did not (negative) produce transient sensory, motor, or language disturbance-were identified prior to tumor resection and documented by intraoperative photography for categorization into functional maps. In this group of 561 patients, 18 were identified who underwent repeat surgery in which 1 or more stimulation sites overlapped with those tested during the initial surgery. The authors compared intraoperative sensory, motor, or language mapping results between initial and repeat surgeries, and evaluated the clinical outcomes for these patients. RESULTS A total of 117 sites were tested for sensory (7 sites, 6.0%), motor (9 sites, 7.7%), or language (101 sites, 86.3%) function during both initial and repeat surgeries. The mean interval between surgical procedures was 4.1 years. During initial surgeries, 95 (81.2%) of 117 sites were found to be negative and 22 (18.8%) of 117 sites were found to be positive. During repeat surgeries, 103 (88.0%) of 117 sites were negative and 14 (12.0%) of 117 were positive. Of the 95 sites that were negative at the initial surgery, 94 (98.9%) were also negative at the repeat surgery, while 1 (1.1%) site was found to be positive. Of the 22 sites that were initially positive, 13 (59.1%) remained positive at repeat surgery, while 9 (40.9%) had become

THE EFFECTS OF SINGLE VERSUS REPEATED PLYOMETRICS ON LANDING BIOMECHANICS AND JUMPING PERFORMANCE IN MEN

Directory of Open Access Journals (Sweden)

H. Makaruk

2014-07-01

Full Text Available The aim of this study was to examine the chronic effects of single and repeated jumps training on vertical landing force (VGRF and jump height in untrained men. The VGRF and jump height were compared after a six-week plyometric training programme containing single and repeated jumps, together with two additional parameters: landing time (LT and range of the knee flexion during landing (KF. Thirty-six untrained physical education students with a plyometric training background were randomly assigned to a single jump group (SJG, n =12, repeated jumps group (RJG, n =12, and control group (CON, n =12. The SJG performed only single jumps, the RJG executed repeated (consecutive jumps, whereas the CON did not perform any exercises at all. A countermovement jump (CMJ, repeated countermovement jumps (RCMJ, and a drop jump (DJ were tested before and after the training. Only the RJG showed a significantly reduced VGRF (p<0.05 in all tests. Both plyometric groups significantly improved (p<0.05 their jump height in all tests. The LT was significantly greater in the RJG, compared to the SJG, in all tests. The KF was also significantly (p<0.05 greater in the RJG than in the SJG for CMJ and RCMJ. The results suggest that repeated jumps are beneficial for simultaneous landing force reduction and jumping performance enhancement.

Repeated E-Book Reading and Its Contribution to Learning New Words among Kindergartners

Science.gov (United States)

Korat, Ofra; Kozlov-Peretz, Olla; Segal-Drori, Ora

2017-01-01

The contribution of repeated e-book reading with and without word explanation support and its effect on receptive and expressive word learning among preschoolers was examined. Seventy-eight kindergartners were randomly divided into an experimental and a control group. The experimental group received two individual reading sessions of an e-book…

Impact of depressive symptoms, self-esteem and neuroticism on trajectories of overgeneral autobiographical memory over repeated trials.

Science.gov (United States)

Kashdan, Todd B; Roberts, John E; Carlos, Erica L

2006-04-01

The present study examined trajectories of change in the frequency of overgeneral autobiographical memory (OGM) over the course of repeated trials, and tested whether particular dimensions of depressive symptomatology (somatic and cognitive-affective distress), self-esteem, and neuroticism account for individual differences in these trajectories. Given that depression is associated with impairments in effortful processing, we predicted that over repeated trials depression would be associated with increasingly OGM. Generalised Linear Mixed Models with Penalised Quasi-Likelihood demonstrated significant linear and quadratic trends in OGM over repeated trials, and somatic distress and self-esteem moderated these slopes. The form of these interactions suggested that somatic distress and low self-esteem primarily contribute to OGM during the second half of the trial sequence. The present findings demonstrate the value of a novel analytical approach to OGM that estimates individual trajectories of change over repeated trials.

Ubiquitous expression of CUG or CAG trinucleotide repeat RNA causes common morphological defects in a Drosophila model of RNA-mediated pathology.

Directory of Open Access Journals (Sweden)

Kynan T Lawlor

Full Text Available Expanded DNA repeat sequences are known to cause over 20 diseases, including Huntington's disease, several types of spinocerebellar ataxia and myotonic dystrophy type 1 and 2. A shared genetic basis, and overlapping clinical features for some of these diseases, indicate that common pathways may contribute to pathology. Multiple mechanisms, mediated by both expanded homopolymeric proteins and expanded repeat RNA, have been identified by the use of model systems, that may account for shared pathology. The use of such animal models enables identification of distinct pathways and their 'molecular hallmarks' that can be used to determine the contribution of each pathway in human pathology. Here we characterise a tergite disruption phenotype in adult flies, caused by ubiquitous expression of either untranslated CUG or CAG expanded repeat RNA. Using the tergite phenotype as a quantitative trait we define a new genetic system in which to examine 'hairpin' repeat RNA-mediated cellular perturbation. Further experiments use this system to examine whether pathways involving Muscleblind sequestration or Dicer processing, which have been shown to mediate repeat RNA-mediated pathology in other model systems, contribute to cellular perturbation in this model.

Examiner Reliability of Fluorosis Scoring: A Comparison of Photographic and Clinical Examination Findings

Science.gov (United States)

Cruz-Orcutt, Noemi; Warren, John J.; Broffitt, Barbara; Levy, Steven M.; Weber-Gasparoni, Karin

2012-01-01

Objective To assess and compare examiner reliability of clinical and photographic fluorosis examinations using the Fluorosis Risk Index (FRI) among children in the Iowa Fluoride Study (IFS). Methods The IFS examined 538 children for fluorosis and dental caries at age 13 and obtained intra-oral photographs from nearly all of them. To assess examiner reliability, duplicate clinical examinations were conducted for 40 of the subjects. In addition, 200 of the photographs were scored independently for fluorosis by two examiners in a standardized manner. Fluorosis data were compared between examiners for the clinical exams and separately for the photographic exams, and a comparison was made between clinical and photographic exams. For all 3 comparisons, examiner reliability was assessed using kappa statistics at the tooth level. Results Inter-examiner reliability for the duplicate clinical exams on the sample of 40 subjects as measured by kappa was 0.59, while the repeat exams of the 200 photographs yielded a kappa of 0.64. For the comparison of photographic and clinical exams, inter-examiner reliability, as measured by weighted kappa, was 0.46. FRI scores obtained using the photographs were higher on average than those obtained from the clinical exams. Fluorosis prevalence was higher for photographs (33%) than found for clinical exam (18%). Conclusion Results suggest inter-examiner reliability is greater and fluorosis scores higher when using photographic compared to clinical examinations. PMID:22316120

Characterization of the repeat expansion size in C9orf72 in amyotrophic lateral sclerosis and frontotemporal dementia.

Science.gov (United States)

Dols-Icardo, Oriol; García-Redondo, Alberto; Rojas-García, Ricard; Sánchez-Valle, Raquel; Noguera, Aina; Gómez-Tortosa, Estrella; Pastor, Pau; Hernández, Isabel; Esteban-Pérez, Jesús; Suárez-Calvet, Marc; Antón-Aguirre, Sofía; Amer, Guillermo; Ortega-Cubero, Sara; Blesa, Rafael; Fortea, Juan; Alcolea, Daniel; Capdevila, Aura; Antonell, Anna; Lladó, Albert; Muñoz-Blanco, José Luís; Mora, Jesús S; Galán-Dávila, Lucía; Rodríguez De Rivera, Francisco Javier; Lleó, Alberto; Clarimón, Jordi

2014-02-01

Hexanucleotide repeat expansions within the C9orf72 gene are the most important genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The difficulty of developing a precise method to determine the expansion size has hampered the study of possible correlations between the hexanucleotide repeat number and clinical phenotype. Here we characterize, through a new non-radioactive Southern blot protocol, the expansion size range in a series of 38 ALS and 22 FTD heterozygous carriers of >30 copies of the repeat. Maximum, median and modal hexanucleotide repeat number were higher in ALS patients than in FTD patients (P< 0.05 in all comparisons). A higher median number of repeats correlated with a bigger range of repeat sizes (Spearman's ρ = 0.743, P = 1.05 × 10(-11)). We did not find any correlation between age of onset or disease duration with the repeat size in neither ALS nor FTD mutation carriers. Clinical presentation (bulbar or spinal) in ALS patients did not correlate either with the repeat length. We finally analyzed two families with affected and unaffected repeat expansion carriers, compared the size of the repeat expansion between two monozygotic (MZ) twins (one affected of ALS and the other unaffected), and examined the expansion size in two different tissues (cerebellum and peripheral blood) belonging to the same FTD patient. The results suggested that the length of the C9orf72 repeat varies between family members, including MZ twins, and among different tissues from the same individual.

Digital repeat analysis; setup and operation.

Science.gov (United States)

Nol, J; Isouard, G; Mirecki, J

2006-06-01

Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors.

Apraxia of Speech: Perceptual Analysis of Trisyllabic Word Productions across Repeated Sampling Occasions

Science.gov (United States)

Mauszycki, Shannon C.; Wambaugh, Julie L.; Cameron, Rosalea M.

2012-01-01

Purpose: Early apraxia of speech (AOS) research has characterized errors as being variable, resulting in a number of different error types being produced on repeated productions of the same stimuli. Conversely, recent research has uncovered greater consistency in errors, but there are limited data examining sound errors over time (more than one…

TH-E-209-01: Fluoroscopic Dose Monitoring and Patient Follow-Up Program at Massachusetts General Hospital

International Nuclear Information System (INIS)

Liu, B.

2016-01-01

Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

TH-E-209-01: Fluoroscopic Dose Monitoring and Patient Follow-Up Program at Massachusetts General Hospital

Energy Technology Data Exchange (ETDEWEB)

Liu, B. [Massachusetts General Hospital (United States)

2016-06-15

Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

The Student Volunteer Army: a 'repeat emergent' emergency response organisation.

Science.gov (United States)

Carlton, Sally; Mills, Colleen E

2017-10-01

This paper seeks to contribute to understanding of the factors associated with an effective emergent emergency response organisation and to provide new insights into this understudied area. It examines, through an analysis of a range of textual resources, the emergence and re-emergence of the Student Volunteer Army (SVA) during the devastating earthquakes in Canterbury, New Zealand, in 2010-11. This evaluation is conducted in relation to the four key features of an effective emergency response organisation: adaptability; direction; leadership; and communication. In addition, the paper aims to further understanding of 'emergency entrepreneurship' and thus of the values and strategies that underpin social entrepreneur organisations in times of normalcy. The paper concludes that the unique position of the SVA as a 'repeat emergent' emergency response organisation enabled it to innovate continually and to improve repeatedly its systems, relationships, and image, such that it exhibited features common to emergent and established emergency response organisations. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

Comparability and repeatability of three commonly used methods for measuring endurance capacity.

Science.gov (United States)

Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

2017-12-01

Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

Genus-specific protein binding to the large clusters of DNA repeats (short regularly spaced repeats) present in Sulfolobus genomes

DEFF Research Database (Denmark)

Peng, Xu; Brügger, Kim; Shen, Biao

2003-01-01

terminally modified and corresponds to SSO454, an open reading frame of previously unassigned function. It binds specifically to DNA fragments carrying double and single repeat sequences, binding on one side of the repeat structure, and producing an opening of the opposite side of the DNA structure. It also...... recognizes both main families of repeat sequences in S. solfataricus. The recombinant protein, expressed in Escherichia coli, showed the same binding properties to the SRSR repeat as the native one. The SSO454 protein exhibits a tripartite internal repeat structure which yields a good sequence match...... with a helix-turn-helix DNA-binding motif. Although this putative motif is shared by other archaeal proteins, orthologs of SSO454 were only detected in species within the Sulfolobus genus and in the closely related Acidianus genus. We infer that the genus-specific protein induces an opening of the structure...

Coexistence of 3G repeaters with LTE base stations.

Science.gov (United States)

Yeo, Woon-Young; Lee, Sang-Min; Hwang, Gyung-Ho; Kim, Jae-Hoon

2013-01-01

Repeaters have been an attractive solution for mobile operators to upgrade their wireless networks at low cost and to extend network coverage effectively. Since the first LTE commercial deployment in 2009, many mobile operators have launched LTE networks by upgrading their 3G and legacy networks. Because all 3G frequency bands are shared with the frequency bands for LTE deployment and 3G mobile operators have an enormous number of repeaters, reusing 3G repeaters in LTE networks is definitely a practical and cost-efficient solution. However, 3G repeaters usually do not support spatial multiplexing with multiple antennas, and thus it is difficult to reuse them directly in LTE networks. In order to support spatial multiplexing of LTE, the role of 3G repeaters should be replaced with small LTE base stations or MIMO-capable repeaters. In this paper, a repeater network is proposed to reuse 3G repeaters in LTE deployment while still supporting multilayer transmission of LTE. Interestingly, the proposed network has a higher cluster throughput than an LTE network with MIMO-capable repeaters.

Repeatability & Workability Evaluation of SIGMOD 2009

KAUST Repository

Manegold, Stefan

2010-12-15

SIGMOD 2008 was the first database conference that offered to test submitters\\' programs against their data to verify the repeatability of the experiments published [1]. Given the positive feedback concerning the SIGMOD 2008 repeatability initiative, SIGMOD 2009 modified and expanded the initiative with a workability assessment.

Repeatability & Workability Evaluation of SIGMOD 2009

KAUST Repository

Manegold, Stefan; Manolescu, Ioana; Afanasiev, Loredana; Feng, Jieling; Gou, G.; Hadjieleftheriou, Marios; Harizopoulos, Stavros; Kalnis, Panos; Karanasos, Konstantinos; Laurent, Dominique; Lupu, M.; Onose, N.; Ré , C.; Sans, Virginie; Senellart, Pierre; Wu, T.; Shasha, Dennis E.

2010-01-01

SIGMOD 2008 was the first database conference that offered to test submitters' programs against their data to verify the repeatability of the experiments published [1]. Given the positive feedback concerning the SIGMOD 2008 repeatability initiative, SIGMOD 2009 modified and expanded the initiative with a workability assessment.

Firefighting and mental health: Experiences of repeated exposure to trauma.

Science.gov (United States)

Jahnke, Sara A; Poston, Walker S Carlos; Haddock, Christopher K; Murphy, Beth

2016-02-15

Firefighters must be ready to respond to a broad range of emergencies every duty day. In the course of many of these emergencies, firefighters witness events which have the potential to induce emotional trauma, such as badly injured people, deceased children, and individuals who are highly distraught. Previous research suggests that repeated exposure to these traumas (RET) may have negative impacts on the emotional and mental health of fire service personnel. Research on the mental health of firefighters has been limited to small surveys reporting the prevalence of specific mental health problems such as depression and post-traumatic stress disorder among firefighters. Despite the likelihood that RET leads to negative outcomes in firefighters, data is lacking on how exposure impacts fire service personnel. The current study examines the experiences of firefighters related to RET. Using formative research methods, we examined the beliefs and experiences of firefighters and administrators from across the United States regarding the impact of RET on firefighter health. Study findings highlight the cumulative psychological toll of repeated exposure to traumatic events including desensitization, flashbacks, and irritability. Results of the current study suggest that RET is a significant concern for emergency responders that warrants additional research and attention. It is likely that the long term consequences of RET are closely intertwined with other mental health outcomes and general well-being of this important occupational group.

Study of Optimal Perimetric Testing in Children (OPTIC: Feasibility, Reliability and Repeatability of Perimetry in Children.

Directory of Open Access Journals (Sweden)

Dipesh E Patel

Full Text Available To investigate feasibility, reliability and repeatability of perimetry in children.A prospective, observational study recruiting 154 children aged 5-15 years, without an ophthalmic condition that affects the visual field (controls, identified consecutively between May 2012 and November 2013 from hospital eye clinics. Perimetry was undertaken in a single sitting, with standardised protocols, in a randomised order using the Humphrey static (SITA 24-2 FAST, Goldmann and Octopus kinetic perimeters. Data collected included test duration, subjective experience and test quality (incorporating examiner ratings on comprehension of instructions, fatigue, response to visual and auditory stimuli, concentration and co-operation to assess feasibility and reliability. Testing was repeated within 6 months to assess repeatability.Overall feasibility was very high (Goldmann=96.1%, Octopus=89% and Humphrey=100% completed the tests. Examiner rated reliability was 'good' in 125 (81.2% children for Goldmann, 100 (64.9% for Octopus and 98 (63.6% for Humphrey perimetry. Goldmann perimetry was the most reliable method in children under 9 years of age. Reliability improved with increasing age (multinomial logistic regression (Goldmann, Octopus and Humphrey, p<0.001. No significant differences were found for any of the three test strategies when examining initial and follow-up data outputs (Bland-Altman plots, n=43, suggesting good test repeatability, although the sample size may preclude detection of a small learning effect.Feasibility and reliability of formal perimetry in children improves with age. By the age of 9 years, all the strategies used here were highly feasible and reliable. Clinical assessment of the visual field is achievable in children as young as 5 years, and should be considered where visual field loss is suspected. Since Goldmann perimetry is the most effective strategy in children aged 5-8 years and this perimeter is no longer available, further

FRB 121102: A Starquake-induced Repeater?

Science.gov (United States)

Wang, Weiyang; Luo, Rui; Yue, Han; Chen, Xuelei; Lee, Kejia; Xu, Renxin

2018-01-01

Since its initial discovery, the fast radio burst (FRB) FRB 121102 has been found to be repeating with millisecond-duration pulses. Very recently, 14 new bursts were detected by the Green Bank Telescope during its continuous monitoring observations. In this paper, we show that the burst energy distribution has a power-law form which is very similar to the Gutenberg–Richter law of earthquakes. In addition, the distribution of burst waiting time can be described as a Poissonian or Gaussian distribution, which is consistent with earthquakes, while the aftershock sequence exhibits some local correlations. These findings suggest that the repeating FRB pulses may originate from the starquakes of a pulsar. Noting that the soft gamma-ray repeaters (SGRs) also exhibit such distributions, the FRB could be powered by some starquake mechanisms associated with the SGRs, including the crustal activity of a magnetar or solidification-induced stress of a newborn strangeon star. These conjectures could be tested with more repeating samples.

Reproducibility of regional DEXA examinations of abdominal fat and lean tissue.

Science.gov (United States)

Tallroth, Kaj; Kettunen, Jyrki A; Kujala, Urho M

2013-01-01

The aim of this study was to develop and test the validity of a new repeatable method to delimit abdominal areas for follow-up of fat mass (FM) and lean tissue mass (LM) in DEXA examinations. 37 male volunteers underwent two DEXA examinations. Total body FM and LM measurements and corresponding abdominal measurements in a carefully defined region were calculated from the first scan. After repositioning of the subjects and a second scan, the delimited region was copied and the abdominal tissues re-calculated. The mean LM of the abdominal area was 2.804 kg (SD 0.556), and the mean FM was 1.026 kg (SD 0.537). The intra-class correlation coefficient for the repeated abdominal LM, FM, and LM/FM ratio measurements was 0.99. The mean difference (bias) for the repeated abdominal LM measurements was -13 g (95% confidence interval (CI) -193.0 to 166.8), and for the repeated abdominal FM measurements it was -35 g (95% CI -178.9 to 108.5). The results indicate that regional DEXA is a sensitive method with excellent reproducibility in the measurements of the abdominal fat and lean tissues. The method may serve as a useful tool for evaluation and follow-up of various dietary and training programmes.

Evaluation of the dosimetric performance characteristic of fluoroscopy system used in medicine

International Nuclear Information System (INIS)

Qi Xuesong; Wei Kedao; Cheng Yuxi; Zhou Qifu; Ge Lijuan; Hou Changsong

2001-01-01

Objective: To discuss establishment of diagnostic reference dose value in fluoroscopic examinations for survey of 16 different types of fluoroscopy systems. Methods: Choosing dosimetric characteristic parameters including: IIESDR, ESDR (typical value) and ESDR max (ESDR maximum), and DAP, which was calibrated in situ on the X-ray unit. Results: Results of dose survey are summarized in three tables, from these we could get wide changes in accordance with those in many other countries resulting from maximum and minimum of IIESDR, ESDR and ESDRmax when measurements were performed at same entrance field size on I.I. Image Intensifier of the 15 fluoroscopy systems and under conditions of ABC. And also we could get less changes of DAP mean values, though differences for patient weight, technological parameters of fluoroscopic exam setting, fluoroscopic time and number of film were more remarkable. Conclusions: Measurements on IIESDR, ESDR (typical value) and ESDRmax (ESDR maximum) are not satisfied as diagnostic reference level. But it is suggested that DAP values, in fluoroscopic exam, are used as a tool to achieve this. (author)

Repeat Syphilis Among Men Who Have Sex With Men in California, 2002–2006: Implications for Syphilis Elimination Efforts

Science.gov (United States)

Chew Ng, Rilene A.; Katz, Kenneth A.; Bernstein, Kyle T.; Samuel, Michael C.; Kerndt, Peter R.; Bolan, Gail

2012-01-01

Objectives. We examined rates of and risk factors for repeat syphilis infection among men who have sex with men (MSM) in California. Methods. We analyzed 2002 to 2006 California syphilis surveillance system data. Results. During the study period, a mean of 5.9% (range: 4.9%–7.1% per year) of MSM had a repeat primary or secondary (PS) syphilis infection within 2 years of an initial infection. There was no significant increase in the annual proportion of MSM with a repeat syphilis infection (P = .42). In a multivariable model, factors associated with repeat syphilis infection were HIV infection (odds ratio [OR] = 1.65; 95% confidence interval [CI] = 1.14, 2.37), Black race (OR = 1.84; 95% CI = 1.12, 3.04), and 10 or more recent sex partners (OR = 1.99; 95% CI = 1.12, 3.50). Conclusions. Approximately 6% of MSM in California have a repeat PS syphilis infection within 2 years of an initial infection. HIV infection, Black race, and having multiple sex partners are associated with increased odds of repeat infection. Syphilis elimination efforts should include messages about the risk for repeat infection and the importance of follow-up testing. Public health attention to individuals repeatedly infected with syphilis may help reduce local disease burdens. PMID:22095364

Relational stressors as predictors for repeat aggressive and self-harming incidents in child and adolescent psychiatric inpatient settings.

Science.gov (United States)

Ulke, Christine; Klein, Annette M; von Klitzing, Kai

2014-01-01

This study examined whether relational stressors such as psychosocial stressors, the therapist's absence and a change of therapist are associated with repeat aggressive or self-harming incidents in child and adolescent psychiatric inpatient care. The study data were derived from critical incident reports and chart reviews of 107 inpatients. In multinomial regression analysis, patients with repeat aggressive or self-harming incidents were compared with patients with single incidents. Results suggested that a higher number of psychosocial stressors and a change of therapist, but not the therapist's absence are predictors for repeat aggressive and self-harming incidents. There was a high prevalence of therapist's absence during both, single and repeat, incidents. Repeat aggressive incidents were common in male children and adolescents with disruptive behavior disorders. Repeat self-harming incidents were common in adolescent females with trauma-related disorders. Patients with repeat aggressive or self-harming incidents had a higher number of abnormal intrafamilial relationships and acute life events than patients with single incidents. Interventions to reduce a change of therapist should in particular target children and adolescents with a higher number of psychosocial stressors and/or a known history of traumatic relational experiences. After a first incident, patients should have a psychosocial assessment to evaluate whether additional relational support is needed.

Lesser Neural Pattern Similarity across Repeated Tests Is Associated with Better Long-Term Memory Retention.

Science.gov (United States)

Karlsson Wirebring, Linnea; Wiklund-Hörnqvist, Carola; Eriksson, Johan; Andersson, Micael; Jonsson, Bert; Nyberg, Lars

2015-07-01

Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability--the altering or adding of underlying memory representations. Human participants studied 60 Swahili-Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgotten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. Repeated testing is known to produce superior long-term retention of the to-be-learned material compared with repeated encoding and other learning techniques, much because it fosters repeated memory retrieval. This study demonstrates that repeated memory

Fluoroscopic-guided radiofrequency ablation of the basivertebral nerve: application and analysis with multiple imaging modalities in an ovine model (Invited Paper)

Science.gov (United States)

Bergeron, Jeffrey A.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, Thomas P.; Pellegrino, Richard; Sutton, Jeffrey; Crombie, John; Paul, B. T.; Hoopes, P. J.

2005-04-01

Pathologic involvement of the basivertebral nerve, an intraosseous vertebral nerve found in humans and most mammalian species, may play a role in some forms of back pain. This study was designed to assess the feasibility and effects of the percutaneous delivery of radiofrequency (RF) energy to thermally ablate the basivertebral nerve in the lumbar vertebrae of mature sheep. Using fluoroscopic guidance, a RF bipolar device was placed and a thermal dose delivered to lumbar vertebral bodies in sheep. Post-treatment assessment included multiple magnetic resonance imaging (MRI) techniques and computed tomography (CT). These data were analyzed and correlated to histopathology and morphometry findings to describe the cellular and boney structural changes resulting from the treatment. Imaging modalities MRI and CT can be implemented to non-invasively describe treatment region and volume, marrow cellular effects, and bone density alterations immediately following RF treatment and during convalescence. Such imaging can be utilized to assess treatment effects and refine the thermal dose to vertebral body volume ratio used in treatment planning. This information will be used to improve the therapeutic ratio and develop a treatment protocol for human applications.

Novel expressed sequence tag- simple sequence repeats (EST ...

African Journals Online (AJOL)

Using different bioinformatic criteria, the SUCEST database was used to mine for simple sequence repeat (SSR) markers. Among 42,189 clusters, 1,425 expressed sequence tag- simple sequence repeats (EST-SSRs) were identified in silico. Trinucleotide repeats were the most abundant SSRs detected. Of 212 primer pairs ...

Role of memory errors in quantum repeaters

International Nuclear Information System (INIS)

Hartmann, L.; Kraus, B.; Briegel, H.-J.; Duer, W.

2007-01-01

We investigate the influence of memory errors in the quantum repeater scheme for long-range quantum communication. We show that the communication distance is limited in standard operation mode due to memory errors resulting from unavoidable waiting times for classical signals. We show how to overcome these limitations by (i) improving local memory and (ii) introducing two operational modes of the quantum repeater. In both operational modes, the repeater is run blindly, i.e., without waiting for classical signals to arrive. In the first scheme, entanglement purification protocols based on one-way classical communication are used allowing to communicate over arbitrary distances. However, the error thresholds for noise in local control operations are very stringent. The second scheme makes use of entanglement purification protocols with two-way classical communication and inherits the favorable error thresholds of the repeater run in standard mode. One can increase the possible communication distance by an order of magnitude with reasonable overhead in physical resources. We outline the architecture of a quantum repeater that can possibly ensure intercontinental quantum communication

Ocular surface sensitivity repeatability with Cochet-Bonnet esthesiometer.

Science.gov (United States)

Chao, Cecilia; Stapleton, Fiona; Badarudin, Ezailina; Golebiowski, Blanka

2015-02-01

To determine the repeatability of ocular surface threshold measurements using the Cochet-Bonnet esthesiometer on the same day and 3 months apart. Two separate studies were conducted to determine the repeatability of ocular surface threshold measurements made on the same day (n = 20 subjects) and 3 months apart (n = 29 subjects). The Cochet-Bonnet esthesiometer was used to measure corneal and inferior conjunctival thresholds using the ascending method of limits. The pressure exerted by the Cochet-Bonnet esthesiometer was determined using an analytical balance, for both the 0.08- and 0.12-mm-diameter filaments. This calibration was then used to convert filament length measurements to pressure. Repeatability was determined using a Bland and Altman analysis. The pressure exerted at each filament length differed between the two filament diameters. The measured pressure also differed from values provided by the manufacturer. Repeatability of threshold measurements at the central cornea was shown to be good, with better repeatability for same-day measurements (coefficient of repeatability [CoR] = ±0.23 g/mm²) than for those 3 months apart (CoR = ±0.52 g/mm²). Threshold measurements at the inferior conjunctiva, in contrast, were poorly repeatable (CoR = ±12.78 g/mm²). Cochet-Bonnet esthesiometry is repeatable when performed on the central cornea on the same day and 3 months apart, but this instrument is not recommended for conjunctival threshold measurements.

How repeated 15-minute assertiveness training sessions reduce wrist cutting in patients with borderline personality disorder.

Science.gov (United States)

Hayakawa, Masaya

2009-01-01

The aim of this work was to examine a possible treatment for patients with borderline personality disorder who have wrist-cutting syndrome, a condition characterized by repeated, superficial wrist cutting in a non-suicidal fashion. Within the current healthcare system in Japan, the average amount of time a doctor can spend with a psychiatric outpatient is about 8 to 15 minutes. We, therefore, examined whether repeated 15-minute psychotherapy sessions to improve patient assertiveness would be effective for reducing wrist cutting and possibly other forms of self-mutilation. We treated 13 patients diagnosed with borderline personality disorder and wrist-cutting syndrome with assertiveness training during 15-minute, biweekly therapy sessions over a course of one to four years. At the conclusion of psychotherapeutic treatment, 69% of outpatients showed a statistically significant reduction in wrist-cutting behavior.

Safety of Repeated Yttrium-90 Radioembolization

International Nuclear Information System (INIS)

Lam, Marnix G. E. H.; Louie, John D.; Iagaru, Andrei H.; Goris, Michael L.; Sze, Daniel Y.

2013-01-01

Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver’s cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51–71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction

Safety of Repeated Yttrium-90 Radioembolization

Energy Technology Data Exchange (ETDEWEB)

Lam, Marnix G. E. H.; Louie, John D. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Iagaru, Andrei H.; Goris, Michael L. [Stanford University School of Medicine, Division of Nuclear Medicine (United States); Sze, Daniel Y., E-mail: dansze@stanford.edu [Stanford University School of Medicine, Division of Interventional Radiology (United States)

2013-10-15

Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

The importance of position and path repeatability on force at the knee during six-DOF joint motion.

Science.gov (United States)

Darcy, Shon P; Gil, Jorge E; Woo, Savio L-Y; Debski, Richard E

2009-06-01

Mechanical devices, such as robotic manipulators have been designed to measure joint and ligament function because of their ability to position a diarthrodial joint in six degrees-of-freedom with fidelity. However, the precision and performance of these testing devices vary. Therefore, the objective of this study was to determine the effect of systematic errors in position and path repeatability of two high-payload robotic manipulators (Manipulators 1 and 2) on the resultant forces at the knee. Using a porcine knee, the position and path repeatability of these manipulators were determined during passive flexion-extension with a coordinate measuring machine. The position repeatability of Manipulator 1 was 0.3 mm in position and 0.2 degrees in orientation while Manipulator 2 had a better position repeatability of 0.1 mm in position and 0.1 degrees in orientation throughout the range of positions examined. The corresponding variability in the resultant force at the knee for these assigned positions was 32+/-33 N for Manipulator 1 and 4+/-1 N for Manipulator 2. Furthermore, the repeatability of the trajectory of each manipulator while moving between assigned positions (path repeatability) was 0.8 mm for Manipulator 1 while the path repeatability for Manipulator 2 was improved (0.1 mm). These path discrepancies produced variability in the resultant force at the knee of 44+/-24 and 21+/-8 N, respectively, for Manipulators 1 and 2 primarily due to contact between the articular surfaces of the tibia and femur. Therefore, improved position and path repeatability yields lower variability in the resultant forces at the knee. Although position repeatability has been the most common criteria for evaluating biomechanical testing devices, the current study has clearly demonstrated that path repeatability can have an even larger effect on the variability in resultant force at the knee. Consequently, the repeatability of the path followed by the joint throughout its prescribed

Dental Fear in Children with Repeated Tooth Injuries.

Science.gov (United States)

Negovetić Vranić, Dubravka; Ivančić Jokić, Nataša; Bakarčić, Danko; Carek, Andreja; Rotim, Željko; Verzak, Željko

2016-06-01

Tooth injuries are serious clinical conditions. Some children experience dental trauma only once, while others are more prone to repeated tooth injuries. Repeated dental trauma occurs in 19.4% to 30% of patients. Pain and dental trauma are the most common reasons for fear and anxiety. The main objective of this study was to investigate how dental trauma, as well as repeated dental trauma affects the occurrence and development of dental fear in children. The study was conducted on a random sample of 147 subjects (88 boys and 59 girls) aged 5-8 and 9-12 years. Subjects in both age groups were divided into subroups without dental trauma, with one dental trauma and with repeated dental trauma. The validated Children’s Fear Survey Schedule – Dental Subscale was used on fear assessment. Results showed that only 12.2% of children without trauma, 33.3% with one trauma and 51.7% with repeated trauma were not afraid of injection. Older children had a significantly lower fear of injections, touch of an unknown person, choking, going to the hospital and people in white uniforms. Dentist was not the cause of fear in 65.5% of patients with repeated trauma. With each repeated injury of teeth, the degree of their fear of dental treatment was lower.

Erroneous Memories Arising from Repeated Attempts to Remember

Science.gov (United States)

Henkel, Linda A.

2004-01-01

The impact of repeated and prolonged attempts at remembering on false memory rates was assessed in three experiments. Participants saw and imagined pictures and then made repeated recall attempts before taking a source memory test. Although the number of items recalled increased with repeated tests, the net gains were associated with more source…

Identification, variation and transcription of pneumococcal repeat sequences

Science.gov (United States)

2011-01-01

Background Small interspersed repeats are commonly found in many bacterial chromosomes. Two families of repeats (BOX and RUP) have previously been identified in the genome of Streptococcus pneumoniae, a nasopharyngeal commensal and respiratory pathogen of humans. However, little is known about the role they play in pneumococcal genetics. Results Analysis of the genome of S. pneumoniae ATCC 700669 revealed the presence of a third repeat family, which we have named SPRITE. All three repeats are present at a reduced density in the genome of the closely related species S. mitis. However, they are almost entirely absent from all other streptococci, although a set of elements related to the pneumococcal BOX repeat was identified in the zoonotic pathogen S. suis. In conjunction with information regarding their distribution within the pneumococcal chromosome, this suggests that it is unlikely that these repeats are specialised sequences performing a particular role for the host, but rather that they constitute parasitic elements. However, comparing insertion sites between pneumococcal sequences indicates that they appear to transpose at a much lower rate than IS elements. Some large BOX elements in S. pneumoniae were found to encode open reading frames on both strands of the genome, whilst another was found to form a composite RNA structure with two T box riboswitches. In multiple cases, such BOX elements were demonstrated as being expressed using directional RNA-seq and RT-PCR. Conclusions BOX, RUP and SPRITE repeats appear to have proliferated extensively throughout the pneumococcal chromosome during the species' past, but novel insertions are currently occurring at a relatively slow rate. Through their extensive secondary structures, they seem likely to affect the expression of genes with which they are co-transcribed. Software for annotation of these repeats is freely available from ftp://ftp.sanger.ac.uk/pub/pathogens/strep_repeats/. PMID:21333003

Repeated causal decision making.

Science.gov (United States)

Hagmayer, York; Meder, Björn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in such situations and how they use their knowledge to adapt to changes in the decision context. Our studies show that decision makers' behavior is strongly contingent on their causal beliefs and that people exploit their causal knowledge to assess the consequences of changes in the decision problem. A high consistency between hypotheses about causal structure, causally expected values, and actual choices was observed. The experiments show that (a) existing causal hypotheses guide the interpretation of decision feedback, (b) consequences of decisions are used to revise existing causal beliefs, and (c) decision makers use the experienced feedback to induce a causal model of the choice situation even when they have no initial causal hypotheses, which (d) enables them to adapt their choices to changes of the decision problem. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Nonparametric additive regression for repeatedly measured data

KAUST Repository

Carroll, R. J.; Maity, A.; Mammen, E.; Yu, K.

2009-01-01

We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements

Emergency Department Referrals for Adolescent Urgent Psychiatric Consultation: Comparison of Clinical Characteristics of Repeat-presentations and Single-presentation.

Science.gov (United States)

Roberts, Nasreen; Nesdole, Robert; Hu, Tina

2018-01-01

a) to examine the demographic and clinical characteristics of repeat-presentations to an adolescent urgent psychiatric clinic, and b) to compare them with single-time presentation. This 18-month retrospective study compared repeat-presenters to age and gender matched single-time presenters. Demographic variables included age gender and ethnicity. Clinical variables included reason for referral, family history, diagnosis, recommendations and compliance. Data were analyzed using descriptive statistics, McNemar's Chi-square tests for matched pairs, and conditional logistic regression. Of 624 assessments 24% (N=151) were repeat-presentations. Compared with single-presentation, repeat-presentation group had a higher proportion of Aboriginal youth (X2 (1) = 108.28 p presentation group had higher odds of past hospital admission (OR: 3.50, p presentations for urgent psychiatric consultation constitute a quarter of referrals to the urgent psychiatric clinic. Identifying and addressing factors that contribute to repeat-presentations may, assist in improving treatment compliance by ensuring focused interventions and service delivery for these youth. In turn, this will improve access to the limited urgent services for other youth.

Quantum key distribution with two-segment quantum repeaters

Energy Technology Data Exchange (ETDEWEB)

Kampermann, Hermann; Abruzzo, Silvestre; Bruss, Dagmar [Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf (Germany)

2014-07-01

Quantum repeaters represent one possible way to achieve long-distance quantum key distribution. One way of improving the repeater rate and decreasing the memory coherence time is the usage of multiplexing. Motivated by the experimental fact that long-range connections are practically demanding, we extend the analysis of the quantum repeater multiplexing protocol to the case of short-range connections. We derive formulas for the repeater rate and we show that short-range connections lead to most of the benefits of a full-range multiplexing protocol. A less demanding QKD-protocol without quantum memories was recently introduced by Lo et al. We generalize this measurement-device-independent quantum key Distribution protocol to the scenario where the repeater Station contains also heralded quantum memories. We assume either single-photon sources or weak coherent pulse sources plus decay states. We show that it is possible to significantly outperform the original proposal, even in presence of decoherence of the quantum memory. We give formulas in terms of device imperfections i.e., the quantum bit error rate and the repeater rate.

Patient Dose Optimization in Fluoroscopically Guided Interventional Procedures. Final Report of a Coordinated Research Project

International Nuclear Information System (INIS)

2010-01-01

In recent years, many surgical procedures have increasingly been replaced by interventional procedures that guide catheters into the arteries under X ray fluoroscopic guidance to perform a variety of operations such as ballooning, embolization, implantation of stents etc. The radiation exposure to patients and staff in such procedures is much higher than in simple radiographic examinations like X ray of chest or abdomen such that radiation induced skin injuries to patients and eye lens opacities among workers have been reported in the 1990's and after. Interventional procedures have grown both in frequency and importance during the last decade. This Coordinated Research Project (CRP) and TECDOC were developed within the International Atomic Energy Agency's (IAEA) framework of statutory responsibility to provide for the worldwide application of the standards for the protection of people against exposure to ionizing radiation. The CRP took place between 2003 and 2005 in six countries, with a view of optimizing the radiation protection of patients undergoing interventional procedures. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation (BSS) issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organization (ILO), the World Health Organization (WHO), the Pan American Health Organization (PAHO) and the Nuclear Energy Agency (NEA), among others, require the radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. In keeping with its responsibility on the application of standards, the IAEA programme on Radiological Protection of Patients encourages the reduction of patient doses. To facilitate this, it has issued specific advice on the application of the BSS in the field of radiology in Safety Reports Series No. 39 and the three volumes on Radiation

Deployment Repeatability

Science.gov (United States)

2016-08-31

large cohort of trials to spot unusual cases. However, deployment repeatability is inherently a nonlinear phenomenon, which makes modeling difficult...and GEMS tip position were both tracked during ground testing by a laser target tracking system. Earlier SAILMAST testing in 2005 [8] used...recalls the strategy used by SRTM, where a constellation of lights was installed at the tip of the boom and a modified star tracker was used to track tip

Variable presence of the inverted repeat and plastome stability in Erodium

OpenAIRE

Blazier, John C.; Jansen, Robert K.; Mower, Jeffrey P.; Govindu, Madhu; Zhang, Jin; Weng, Mao-Lun; Ruhlman, Tracey A.

2016-01-01

Background and Aims Several unrelated lineages such as plastids, viruses and plasmids, have converged on quadripartite genomes of similar size with large and small single copy regions and a large inverted repeat (IR). Except for Erodium (Geraniaceae), saguaro cactus and some legumes, the plastomes of all photosynthetic angiosperms display this structure. The functional significance of the IR is not understood and Erodium provides a system to examine the role of the IR in the long-term stabili...

Repeated superovulation increases the risk of osteoporosis and cardiovascular diseases by accelerating ovarian aging in mice.

Science.gov (United States)

Zhang, Jinjin; Lai, Zhiwen; Shi, Liangyan; Tian, Yong; Luo, Aiyue; Xu, Zheyuan; Ma, Xiangyi; Wang, Shixuan

2018-05-22

Superovulation procedures and assisted reproductive technologies have been widely used to treat couples who have infertility problems. Although generally safe, the superovulation procedures are associated with a series of complications, such as ovarian hyper-stimulation syndrome, thromboembolism, and adnexal torsion. The role of long-term repeated superovulation in ovarian aging and especially in associated disorders such as osteoporosis and cardiovascular diseases is still unclear. In this study, we sought to determine if repeated superovulation by ten cycles of treatment with pregnant mare serum gonadotropin/human chorionic gonadotropin could affect ovarian reserve, ovarian function, bone density and heart function. Ovarian reserve and function were reflected by the size of the primordial follicle pool, anti-Mullerian hormone expressions, hormone levels and fertility status. Furthermore, we examined bone density and heart function by microCT and cardiovascular ultrasonography, respectively. After repeated superovulation, the size of the primordial follicle pool and the expression of anti-mullerian hormone decreased, along with the concentrations of estrogen and progesterone. Mice exposed to repeated superovulation showed an obvious decrease in fertility and fecundity. Furthermore, both bone density and heart ejection fraction significantly decreased. These results suggest that repeated superovulation may increase the risk of osteoporosis and cardiovascular diseases by accelerating ovarian aging.

Reliability of near-infrared spectroscopy for measuring biceps brachii oxygenation during sustained and repeated isometric contractions.

Science.gov (United States)

Muthalib, Makii; Millet, Guillaume Y; Quaresima, Valentina; Nosaka, Kazunori

2010-01-01

We examine the test-retest reliability of biceps brachii tissue oxygenation index (TOI) parameters measured by near-infrared spectroscopy during a 10-s sustained and a 30-repeated (1-s contraction, 1-s relaxation) isometric contraction task at 30% of maximal voluntary contraction (30% MVC) and maximal (100% MVC) intensities. Eight healthy men (23 to 33 yr) were tested on three sessions separated by 3 h and 24 h, and the within-subject reliability of torque and each TOI parameter were determined by Bland-Altman+/-2 SD limits of agreement plots and coefficient of variation (CV). No significant (P>0.05) differences between the three sessions were found for mean values of torque and TOI parameters during the sustained and repeated tasks at both contraction intensities. All TOI parameters were within+/-2 SD limits of agreement. The CVs for torque integral were similar between the sustained and repeated task at both intensities (4 to 7%); however, the CVs for TOI parameters during the sustained and repeated task were lower for 100% MVC (7 to 11%) than for 30% MVC (22 to 36%). It is concluded that the reliability of the biceps brachii NIRS parameters during both sustained and repeated isometric contraction tasks is acceptable.

Cost-effectiveness analysis of repeat fine-needle aspiration for thyroid biopsies read as atypia of undetermined significance.

Science.gov (United States)

Heller, Michael; Zanocco, Kyle; Zydowicz, Sara; Elaraj, Dina; Nayar, Ritu; Sturgeon, Cord

2012-09-01

The 2007 National Cancer Institute (NCI) conference on Thyroid Fine-Needle Aspiration (FNA) introduced the category atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS). Repeat FNA in 3 to 6 months was recommended for low-risk patients. Compliance with these recommendations has been suboptimal. We hypothesized that repeat FNA would be more effective than diagnostic lobectomy, with decreased costs and improved rates of cancer detection. Cost-effectiveness analysis was performed in which we compared diagnostic lobectomy with repeat FNA. A Markov model was developed. Outcomes and probabilities were identified from literature review. Third-party payer costs were estimated in 2010 US dollars. Outcomes were weighted by use of the quality-of-life utility factors, yielding quality-adjusted life years (QALYs). Monte Carlo simulation and sensitivity analysis were used to examine the uncertainty of probability, cost, and utility estimates. The diagnostic lobectomy strategy cost $8,057 and produced 23.99 QALYs. Repeat FNA cost $2,462 and produced 24.05 QALYs. Repeat FNA was dominant until the cost of FNA increased to $6,091. Dominance of the repeat FNA strategy was not sensitive to the cost of operation or the complication rate. The NCI recommendations for repeat FNA regarding follow-up of AUS/FLUS results are cost-effective. Improving compliance with these guidelines should lead to less overall costs, greater quality of life, and fewer unnecessary operations. Copyright © 2012 Mosby, Inc. All rights reserved.

R-loops: targets for nuclease cleavage and repeat instability.

Science.gov (United States)

Freudenreich, Catherine H

2018-01-11

R-loops form when transcribed RNA remains bound to its DNA template to form a stable RNA:DNA hybrid. Stable R-loops form when the RNA is purine-rich, and are further stabilized by DNA secondary structures on the non-template strand. Interestingly, many expandable and disease-causing repeat sequences form stable R-loops, and R-loops can contribute to repeat instability. Repeat expansions are responsible for multiple neurodegenerative diseases, including Huntington's disease, myotonic dystrophy, and several types of ataxias. Recently, it was found that R-loops at an expanded CAG/CTG repeat tract cause DNA breaks as well as repeat instability (Su and Freudenreich, Proc Natl Acad Sci USA 114, E8392-E8401, 2017). Two factors were identified as causing R-loop-dependent breaks at CAG/CTG tracts: deamination of cytosines and the MutLγ (Mlh1-Mlh3) endonuclease, defining two new mechanisms for how R-loops can generate DNA breaks (Su and Freudenreich, Proc Natl Acad Sci USA 114, E8392-E8401, 2017). Following R-loop-dependent nicking, base excision repair resulted in repeat instability. These results have implications for human repeat expansion diseases and provide a paradigm for how RNA:DNA hybrids can cause genome instability at structure-forming DNA sequences. This perspective summarizes mechanisms of R-loop-induced fragility at G-rich repeats and new links between DNA breaks and repeat instability.

Repeat profile analysis in an x-ray department

International Nuclear Information System (INIS)

Bassey, C.E.; Ojo, O.O.; Akpabio, I.

1991-01-01

The repeat profile of an x-ray department in a developing country was analysed monthly between July 1989 and June 1990. Results showed an average repeat rate of 3.7% for the period of study. The main causes of film repetition were: equipment fault, 33.9%; radiographer's fault, 27.4%; film fault, 19.3%; processing fault, 10.8% and patient's fault, 8.6%. The average repeat rate in the first 6 months of study reduced by 50% in the last 6 months. This was due to the effectiveness of implementation of corrective actions. The overall repeat rate was found to correlate well with both the equipment fault and radiographer's fault with correlation coefficients, r, of 0.94 and 0.91, respectively. It is expected that a further reduction in the repeat rate will be obtained after the introduction of quality assurance programmes. (author)

Exceptionally long 5' UTR short tandem repeats specifically linked to primates.

Science.gov (United States)

Namdar-Aligoodarzi, P; Mohammadparast, S; Zaker-Kandjani, B; Talebi Kakroodi, S; Jafari Vesiehsari, M; Ohadi, M

2015-09-10

We have previously reported genome-scale short tandem repeats (STRs) in the core promoter interval (i.e. -120 to +1 to the transcription start site) of protein-coding genes that have evolved identically in primates vs. non-primates. Those STRs may function as evolutionary switch codes for primate speciation. In the current study, we used the Ensembl database to analyze the 5' untranslated region (5' UTR) between +1 and +60 of the transcription start site of the entire human protein-coding genes annotated in the GeneCards database, in order to identify "exceptionally long" STRs (≥5-repeats), which may be of selective/adaptive advantage. The importance of this critical interval is its function as core promoter, and its effect on transcription and translation. In order to minimize ascertainment bias, we analyzed the evolutionary status of the human 5' UTR STRs of ≥5-repeats in several species encompassing six major orders and superorders across mammals, including primates, rodents, Scandentia, Laurasiatheria, Afrotheria, and Xenarthra. We introduce primate-specific STRs, and STRs which have expanded from mouse to primates. Identical co-occurrence of the identified STRs of rare average frequency between 0.006 and 0.0001 in primates supports a role for those motifs in processes that diverged primates from other mammals, such as neuronal differentiation (e.g. APOD and FGF4), and craniofacial development (e.g. FILIP1L). A number of the identified STRs of ≥5-repeats may be human-specific (e.g. ZMYM3 and DAZAP1). Future work is warranted to examine the importance of the listed genes in primate/human evolution, development, and disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Investigation of first ray mobility during gait by kinematic fluoroscopic imaging-a novel method

Directory of Open Access Journals (Sweden)

Martin Heiner

2012-02-01

Full Text Available Abstract Background It is often suggested that sagittal instability at the first tarso-metatarsal joint level is a primary factor for hallux valgus and that sagittal instability increases with the progression of the deformity. The assessment of the degree of vertical instability is usually made by clinical evaluation while any measurements mostly refer to a static assessment of medial ray mobility (i.e. the plantar/dorsal flexion in the sagittal plane. Testing methods currently available cannot attribute the degree of mobility to the corresponding anatomical joints making up the medial column of the foot. The aim of this study was to develop a technique which allows for a quantification of the in-vivo sagittal mobility of the joints of the medial foot column during the roll-over process under full weight bearing. Methods Mobility of first ray bones was investigated by dynamic distortion-free fluoroscopy (25 frames/s of 14 healthy volunteers and 8 patients with manifested clinical instability of the first ray. A CAD-based evaluation method allowed the determination of mobility and relative displacements and rotations of the first ray bones within the sagittal plane during the stance phase of gait. Results Total flexion of the first ray was found to be 13.63 (SD 6.14 mm with the healthy volunteers and 13.06 (SD 8.01 mm with the patients (resolution: 0.245 mm/pixel. The dorsiflexion angle was 5.27 (SD 2.34 degrees in the healthy volunteers and increased to 5.56 (SD 3.37 degrees in the patients. Maximum rotations were found at the naviculo-cuneiform joints and least at the first tarso-metatarsal joint level in both groups. Conclusions Dynamic fluoroscopic assessment has been shown to be a valuable tool for characterisation of the kinematics of the joints of the medial foot column during gait. A significant difference in first ray flexion and angular rotation between the patients and healthy volunteers however could not be found.

The "saying is repeating" effect: dyadic communication can generate cultural stereotypes.

Science.gov (United States)

Bratanova, Boyka; Kashima, Yoshi

2014-01-01

It has been long established that interpersonal communication underpins the existence of cultural stereotypes. However, research has either examined the formation of new or the maintenance of existing stereotypes. In a series of three studies, the present research bridges the gap between these phases by showing that newly formed stereotypes can spread through repeated dyadic communication with others. The stereotypic representation arose due to the audience tuning in to communication to a first audience. Further transmission to two types of subsequent audiences was simulated: a newcomer and an old-timer with an unknown attitude towards the target. A "saying-is-repeating" effect was obtained: the stereotypic representation was invariably transmitted to the newcomer, regardless of whether communicators personally believed in the bias; perceived group-level consensus moderated its transmission to the old-timer. These findings demonstrate that once a stereotypic representation is formed, it is likely to spread in a community and potentially become a cultural stereotype.

Repeated Sprint Ability in Young Basketball Players: Multi-direction vs. One-Change of Direction (Part 1)

OpenAIRE

Padulo, Johnny; Bragazzi, Nicola L.; Nikolaidis, Pantelis T.; Dello Iacono, Antonio; Attene, Giuseppe; Pizzolato, Fabio; Dal Pupo, Juliano; Zagatto, Alessandro M.; Oggianu, Marcello; Migliaccio, Gian M.

2016-01-01

The aim of the present study was to examine the reliability of a novel multi-direction repeated sprint ability test (RSM; 10×(6×5-m)) compared with a repeated sprint ability test (RSA) with one change of direction (10×(2×15-m)), and the relationship of the RSM and RSA with Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) and jump performances [squat jump (SJ) and counter-movement-jump (CMJ)]. Thirty-six (male, n=14, female n=22) young basketball players (age 16.0±0.9 yrs) performed the RS...

Repeated isoflurane exposure and neuroapoptosis in the midgestation fetal sheep brain.

Science.gov (United States)

Olutoye, Olutoyin A; Sheikh, Fariha; Zamora, Irving J; Yu, Ling; Akinkuotu, Adesola C; Adesina, Adekunle M; Olutoye, Oluyinka O

2016-04-01

Advances in surgery and technology have resulted in increased in-utero procedures. However, the effect of anesthesia on the fetal brain is not fully known. The inhalational anesthetic agent, isoflurane, other gamma amino butyric acid agonists (benzodiazepines, barbiturates, propofol, other inhalation anesthetics), and N-methyl D aspartate antagonists, eg, ketamine, have been shown to induce neuroapoptosis. The ovine model has been used extensively to study maternal-fetal physiologic interactions and to investigate different surgical interventions on the fetus. The purpose of this study was to determine effects of different doses and duration of isoflurane on neuroapoptosis in midgestation fetal sheep. We hypothesized that repeated anesthetic exposure and high concentrations of isoflurane would result in increased neuroapoptosis. Time-dated, pregnant sheep at 70 days gestation (term 145 days) received either isoflurane 2% × 1 hour, 4% × 3 hours, or 2% × 1 hour every other day for 3 exposures (repeated exposure group). Euthanasia occurred following anesthetic exposure and fetal brains were processed. Neuroapoptosis was detected by immunohistochemistry using anticaspase-3 antibodies. Fetuses unexposed to anesthesia served as controls. Another midgestation group with repeated 2% isoflurane exposure was examined at day 130 (long-term group) and neuronal cell density compared to age-matched controls. Representative sections of the brain were analyzed using Aperio Digital imaging (Leica Microsystems Inc, Buffalo Grove, IL). Data, reported by number of neurons per cubic millimeter of brain tissue are presented as means and SEM. Data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests as appropriate. A total of 34 fetuses were studied. There was no significant difference in neuroapoptosis observed in fetuses exposed to 2% isoflurane for 1 hour or 4% isoflurane for 3 hours. Increased neuroapoptosis was observed in the frontal cortex following repeated 2

Repeatability of the Oxford Foot Model for Kinematic Gait Analysis of the Foot and Ankle

NARCIS (Netherlands)

van Hoeve, S.; Vos, J.; Weijers, P.; Verbruggen, J.; Willems, P.; Poeze, M.; Meijer, K.

2015-01-01

INTRODUCTION: Kinematic gait analysis via the multi-segmental Oxford foot model (OFM) may be a valuable addition to the biomechanical examination of the foot and ankle. The aim of this study is to assess the repeatability of the OFM in healthy subjects. METHODS: Nine healthy subjects, without a

Modeling intraindividual variability with repeated measures data methods and applications

CERN Document Server

Hershberger, Scott L

2013-01-01

This book examines how individuals behave across time and to what degree that behavior changes, fluctuates, or remains stable.It features the most current methods on modeling repeated measures data as reported by a distinguished group of experts in the field. The goal is to make the latest techniques used to assess intraindividual variability accessible to a wide range of researchers. Each chapter is written in a ""user-friendly"" style such that even the ""novice"" data analyst can easily apply the techniques.Each chapter features:a minimum discussion of mathematical detail;an empirical examp

GENETIC DIVERSITY OF TYPHA LATIFOLIA (TYPHACEAE) AND THE IMPACT OF POLLUTANTS EXAMINED WITH TANDEM-REPETITIVE DNA PROBES

Science.gov (United States)

Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated "core" sequences (GACA, GATA, and GCAC). The principal objectives of this investigation w...

Relationships Among Two Repeated Activity Tests and Aerobic Fitness of Volleyball Players.

Science.gov (United States)

Meckel, Yoav; May-Rom, Moran; Ekshtien, Aya; Eisenstein, Tamir; Nemet, Dan; Eliakim, Alon

2015-08-01

The purpose of the study was to determine performance indices of a repeated sprint test (RST) and to examine their relationships with performance indices of a repeated jump test (RJT) and with aerobic fitness among trained volleyball players. Sixteen male volleyball players performed RST (6 × 30 m sprints), RJT (6 sets of 6 consecutive jumps), and an aerobic power test (20-m Shuttle Run Test). Performance indices for the RST and the RJT were (a) the ideal 30-m run time (IS), the total run time (TS) of the 6 sprints, and the performance decrement (PD) during the test and (b) the ideal jump height (IJ), the total jump height (TJ) of all the jumps, and the PD during the test, respectively. No significant correlations were found between performance indices of the RST and RJT. Significant correlations were found between PD, IS, and TS in the RST protocol and predicted peak V[Combining Dot Above]O2 (r = -0.60, -0.75, -0.77, respectively). No significant correlations were found between performance indices of the RJT (IJ, TJ, and PD) and peak V[Combining Dot Above]O2. The findings suggest that a selection of repeated activity test protocols should acknowledge the specific technique used in the sport, and that a distinct RJT, rather than the classic RST, is more appropriate for assessing the anaerobic capabilities of volleyball players. The findings also suggest that aerobic fitness plays only a minor role in performance maintenance throughout characteristic repeated jumping activity of a volleyball game.

Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

International Nuclear Information System (INIS)

Hinzpeter, Ricarda; Sprengel, Kai; Wanner, Guido A.; Mildenberger, Peter; Alkadhi, Hatem

2017-01-01

Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

Energy Technology Data Exchange (ETDEWEB)

Hinzpeter, Ricarda, E-mail: Ricarda.Hinzpeter@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland); Sprengel, Kai, E-mail: Kai.Sprengel@usz.ch [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Wanner, Guido A., E-mail: Guido.Wanner@sbk-vs.de [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Department of General Surgery, Schwarzwald-Baar Klinikum, University of Freiburg, Klinikstr. 11, D-78052 Villingen-Schwenningen (Germany); Mildenberger, Peter, E-mail: peter.mildenberger@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, University Hospital of Mainz, Langenbeckstr. 1, D-55131 Mainz (Germany); Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland)

2017-03-15

Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

Anterior prostate biopsy at initial and repeat evaluation: is it useful to detect significant prostate cancer?

Directory of Open Access Journals (Sweden)

Pietro Pepe

2015-10-01

Full Text Available ABSTRACT Purpose: Detection rate for anterior prostate cancer (PCa in men who underwent initial and repeat biopsy has been prospectively evaluated. Materials and Methods: From January 2013 to March 2014, 400 patients all of Caucasian origin (median age 63.5 years underwent initial (285 cases and repeat (115 cases prostate biopsy; all the men had negative digital rectal examination and the indications to biopsy were: PSA values > 10 ng/mL, PSA between 4.1-10 or 2.6-4 ng/mL with free/total PSA≤25% and ≤20%, respectively. A median of 22 (initial biopsy and 31 cores (repeat biopsy were transperineally performed including 4 cores of the anterior zone (AZ and 4 cores of the AZ plus 2 cores of the transition zone (TZ, respectively. Results: Median PSA was 7.9 ng/mL; overall, a PCa was found in 180 (45% patients: in 135 (47.4% and 45 (36% of the men who underwent initial and repeat biopsy, respectively. An exclusive PCa of the anterior zone was found in the 8.9 (initial biopsy vs 13.3% (repeat biopsy of the men: a single microfocus of cancer was found in the 61.2% of the cases; moreover, in 7 out 18 AZ PCa the biopsy histology was predictive of significant cancer in 2 (28.5% and 5 (71.5% men who underwent initial and repeat biopsy, respectively. Conclusions: However AZ biopsies increased detection rate for PCa (10% of the cases, the majority of AZ PCa with histological findings predictive of clinically significant cancer were found at repeat biopsy (about 70% of the cases.

[Effects of repeated firing on microleakage of selective laser melting ceramic crowns].

Science.gov (United States)

Zhong, Qun; Peng, Yan; Wu, Xue-Ying; Weng, Jia-Wei

2016-12-01

To investigate the effects of repeated firing on microleakage of selective laser melting ceramic crowns. Fifty molars were randomly divided into 2 groups (25 teeth in each group). Teeth in group A received a chamfer finish line preparation, whereas teeth in group B received a shoulder finish line. After SLM metal crowns were fabricated, all the crowns received initial oxidation step, opaque firing, dentin firing and glaze firing, then crowns in each group were randomly divided into 5 sub-groups according to different time of clinical firings. Glass ionomer was applied for bonding. After 5000 thermocycles ranging from 5degrees centigrade to 55degrees centigrade, all the specimens was evaluated by dye penetration and then microleakage was examined under light microscopy. The data were analyzed with SPSS 20.0 software package. Microleakage between all specimens of group A were not statistically significant (P>0.05) whereas that of group B were statistically significant (P<0.05); After the fifth time of clinical firing, microleakage of specimens in group B(B5) were significantly higher than that of group A(A5). Repeated firings had no significant influence on marginal microleakage of SLM ceramic crowns whereas the crowns of chamfer finish lines result in better clinical performance after repeated firings.

Development of analog watch with minute repeater

Science.gov (United States)

Okigami, Tomio; Aoyama, Shigeru; Osa, Takashi; Igarashi, Kiyotaka; Ikegami, Tomomi

A complementary metal oxide semiconductor with large scale integration was developed for an electronic minute repeater. It is equipped with the synthetic struck sound circuit to generate natural struck sound necessary for the minute repeater. This circuit consists of an envelope curve drawing circuit, frequency mixer, polyphonic mixer, and booster circuit made by using analog circuit technology. This large scale integration is a single chip microcomputer with motor drivers and input ports in addition to the synthetic struck sound circuit, and it is possible to make an electronic system of minute repeater at a very low cost in comparison with the conventional type.

RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

Directory of Open Access Journals (Sweden)

Aisling Frizzell

2014-03-01

Full Text Available Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG repeat expansions and fragility, likely by unwinding problematic hairpins.

Isolation of human simple repeat loci by hybridization selection.

Science.gov (United States)

Armour, J A; Neumann, R; Gobert, S; Jeffreys, A J

1994-04-01

We have isolated short tandem repeat arrays from the human genome, using a rapid method involving filter hybridization to enrich for tri- or tetranucleotide tandem repeats. About 30% of clones from the enriched library cross-hybridize with probes containing trimeric or tetrameric tandem arrays, facilitating the rapid isolation of large numbers of clones. In an initial analysis of 54 clones, 46 different tandem arrays were identified. Analysis of these tandem repeat loci by PCR showed that 24 were polymorphic in length; substantially higher levels of polymorphism were displayed by the tetrameric repeat loci isolated than by the trimeric repeats. Primary mapping of these loci by linkage analysis showed that they derive from 17 chromosomes, including the X chromosome. We anticipate the use of this strategy for the efficient isolation of tandem repeats from other sources of genomic DNA, including DNA from flow-sorted chromosomes, and from other species.

On balanced minimal repeated measurements designs

Directory of Open Access Journals (Sweden)

Shakeel Ahmad Mir

2014-10-01

Full Text Available Repeated Measurements designs are concerned with scientific experiments in which each experimental unit is assigned more than once to a treatment either different or identical. This class of designs has the property that the unbiased estimators for elementary contrasts among direct and residual effects are obtainable. Afsarinejad (1983 provided a method of constructing balanced Minimal Repeated Measurements designs p < t , when t is an odd or prime power, one or more than one treatment may occur more than once in some sequences and  designs so constructed no longer remain uniform in periods. In this paper an attempt has been made to provide a new method to overcome this drawback. Specifically, two cases have been considered                RM[t,n=t(t-t/(p-1,p], λ2=1 for balanced minimal repeated measurements designs and  RM[t,n=2t(t-t/(p-1,p], λ2=2 for balanced  repeated measurements designs. In addition , a method has been provided for constructing              extra-balanced minimal designs for special case RM[t,n=t2/(p-1,p], λ2=1.

ATXN2 trinucleotide repeat length correlates with risk of ALS.

Science.gov (United States)

Sproviero, William; Shatunov, Aleksey; Stahl, Daniel; Shoai, Maryam; van Rheenen, Wouter; Jones, Ashley R; Al-Sarraj, Safa; Andersen, Peter M; Bonini, Nancy M; Conforti, Francesca L; Van Damme, Philip; Daoud, Hussein; Del Mar Amador, Maria; Fogh, Isabella; Forzan, Monica; Gaastra, Ben; Gellera, Cinzia; Gitler, Aaron D; Hardy, John; Fratta, Pietro; La Bella, Vincenzo; Le Ber, Isabelle; Van Langenhove, Tim; Lattante, Serena; Lee, Yi-Chung; Malaspina, Andrea; Meininger, Vincent; Millecamps, Stéphanie; Orrell, Richard; Rademakers, Rosa; Robberecht, Wim; Rouleau, Guy; Ross, Owen A; Salachas, Francois; Sidle, Katie; Smith, Bradley N; Soong, Bing-Wen; Sorarù, Gianni; Stevanin, Giovanni; Kabashi, Edor; Troakes, Claire; van Broeckhoven, Christine; Veldink, Jan H; van den Berg, Leonard H; Shaw, Christopher E; Powell, John F; Al-Chalabi, Ammar

2017-03-01

We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we systematically searched PubMed for case-control studies published after 1 August 2010 that investigated the association between ATXN2 intermediate repeats and ALS. We conducted a meta-analysis of the new and existing studies for the relative risks of ATXN2 intermediate repeat alleles of between 24 and 34 CAG trinucleotide repeats and ALS. There was an overall increased risk of ALS for those carrying intermediate sized trinucleotide repeat alleles (odds ratio 3.06 [95% confidence interval 2.37-3.94]; p = 6 × 10 -18 ), with an exponential relationship between repeat length and ALS risk for alleles of 29-32 repeats (R 2  = 0.91, p = 0.0002). No relationship was seen for repeat length and age of onset or survival. In contrast to trinucleotide repeat diseases, intermediate ATXN2 trinucleotide repeat expansion in ALS does not predict age of onset but does predict disease risk. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

OpenAIRE

Aisling Frizzell; Jennifer H.G. Nguyen; Mark I.R. Petalcorin; Katherine D. Turner; Simon J. Boulton; Catherine H. Freudenreich; Robert S. Lahue

2014-01-01

SUMMARY Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG·CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vi...

Germ-line CAG repeat instability causes extreme CAG repeat expansion with infantile-onset spinocerebellar ataxia type 2

DEFF Research Database (Denmark)

Vinther-Jensen, Tua; Ek, Jakob; Duno, Morten

2013-01-01

The spinocerebellar ataxias (SCA) are a genetically and clinically heterogeneous group of diseases, characterized by dominant inheritance, progressive cerebellar ataxia and diverse extracerebellar symptoms. A subgroup of the ataxias is caused by unstable CAG-repeat expansions in their respective ...... of paternal germ-line repeat sequence instability of the expanded SCA2 locus.European Journal of Human Genetics advance online publication, 10 October 2012; doi:10.1038/ejhg.2012.231....

Performance Comparisons of Improved Regular Repeat Accumulate (RA and Irregular Repeat Accumulate (IRA Turbo Decoding

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Ahmed Abdulkadhim Hamad

2017-08-01

Full Text Available In this paper, different techniques are used to improve the turbo decoding of regular repeat accumulate (RA and irregular repeat accumulate (IRA codes. The adaptive scaling of a-posteriori information produced by Soft-output Viterbi decoder (SOVA is proposed. The encoded pilots are another scheme that applied for short length RA codes. This work also suggests a simple and a fast method to generate a random interleaver having a free 4 cycle Tanner graph. Progressive edge growth algorithm (PEG is also studied and simulated to create the Tanner graphs which have a great girth.

Behavioral sensitization after repeated formaldehyde exposure in rats.

Science.gov (United States)

Sorg, B A; Hochstatter, T

1999-01-01

Multiple chemical sensitivity (MCS) is a phenomenon whereby individuals report increased sensitivity to chemicals in the environment, and attribute their sensitivities to prior exposure to the same or often structurally unrelated chemicals. A leading hypothesis suggests that MCS is akin to behavioral sensitization observed in rodents after repeated exposure to drugs of abuse or environmental stressors. Sensitization occurring within limbic circuitry of the central nervous system (CNS) may explain the multisymptom complaints in individuals with MCS. The present studies represent the continuing development of an animal model for MCS, the basis of which is the CNS sensitization hypothesis. Three behaviors were assessed in rats repeatedly exposed to formaldehyde (Form) inhalation. In the first series of experiments, rats were given high-dose Form exposure (11 parts per million [ppm]; 1 h/day x 7 days) or low-dose Form exposure (1 ppm; either 1 h/day x 7 days or 1 h/day x 5 days/week x 4 weeks). Within a few days after discontinuing daily Form, cocaine-induced locomotor activity was elevated after high-dose Form or 20 days of low-dose Form inhalation. Approximately 1 month later, cocaine-induced locomotor activity remained significantly elevated in the 20-day Form-exposed rats. The second experiment assessed whether prior exposure to Form (20 days, as above) would alter the ability to condition to an odor (orange oil) paired with footshock. The results suggested a tendency to increase the conditioned fear response to the odor but not the context of the footshock box, and a decreased tendency to extinguish the conditioned fear response to odor. The third experiment examined whether CNS sensitization to daily cocaine or stress would alter subsequent avoidance responding to odor (Form). Daily cocaine significantly elevated approach responses to Form, while daily stress pretreatment produced a trend in the opposite direction, producing greater avoidance of Form. Preliminary

ALTERED HIPPOCAMPAL NEUROGENESIS AND AMYGDALAR NEURONAL ACTIVITY IN ADULT MICE WITH REPEATED EXPERIENCE OF AGGRESSION

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Dmitriy eSmagin

2015-12-01

Full Text Available The repeated experience of winning in a social conflict setting elevates levels of aggression and may lead to violent behavioral patterns. Here we use a paradigm of repeated aggression and fighting deprivation to examine changes in behavior, neurogenesis, and neuronal activity in mice with positive fighting experience. We show that for males, repeated positive fighting experience induces persistent demonstration of aggression and stereotypic behaviors in daily agonistic interactions, enhances aggressive motivation, and elevates levels of anxiety. When winning males are deprived of opportunities to engage in further fights, they demonstrate increased levels of aggressiveness. Positive fighting experience results in increased levels of progenitor cell proliferation and production of young neurons in the hippocampus. This increase is not diminished after a fighting deprivation period. Furthermore, repeated winning experience decreases the number of activated (c-fos positive cells in the basolateral amygdala and increases the number of activated cells in the hippocampus; a subsequent no-fight period restores the number of c-fos-positive cells. Our results indicate that extended positive fighting experience in a social conflict heightens aggression, increases proliferation of neuronal progenitors and production of young neurons in the hippocampus, and decreases neuronal activity in the amygdala; these changes can be modified by depriving the winners of the opportunity for further fights.

Aging and repeated thought suppression success.

Directory of Open Access Journals (Sweden)

Ann E Lambert

Full Text Available Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility.

Analysis of CR1 Repeats in the Zebra Finch Genome

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George E. Liu

2013-06-01

Full Text Available Most bird species have smaller genomes and fewer repeats than mammals. Chicken Repeat 1 (CR1 repeat is one of the most abundant families of repeats, ranging from ~133,000 to ~187,000 copies accounting for ~50 to ~80% of the interspersed repeats in the zebra finch and chicken genomes, respectively. CR1 repeats are believed to have arisen from the retrotransposition of a small number of master elements, which gave rise to multiple CR1 subfamilies in the chicken. In this study, we performed a global assessment of the divergence distributions, phylogenies, and consensus sequences of CR1 repeats in the zebra finch genome. We identified and validated 34 CR1 subfamilies and further analyzed the correlation between these subfamilies. We also discovered 4 novel lineage-specific CR1 subfamilies in the zebra finch when compared to the chicken genome. We built various evolutionary trees of these subfamilies and concluded that CR1 repeats may play an important role in reshaping the structure of bird genomes.

Measurement of repeat effects in Chicago’s criminal social network

Directory of Open Access Journals (Sweden)

Paul Kump

2016-07-01

Full Text Available The “near-repeat” effect is a well-known criminological phenomenon in which the occurrence of a crime incident gives rise to a temporary elevation of crime risk within close physical proximity to an initial incident. Adopting a social network perspective, we instead define a near repeat in terms of geodesic distance within a criminal social network, rather than spatial distance. Specifically, we report a statistical analysis of repeat effects in arrest data for Chicago during the years 2003–2012. We divide the arrest data into two sets (violent crimes and other crimes and, for each set, we compare the distributions of time intervals between repeat incidents to theoretical distributions in which repeat incidents occur only by chance. We first consider the case of the same arrestee participating in repeat incidents (“exact repeats” and then extend the analysis to evaluate repeat risks of those arrestees near one another in the social network. We observe repeat effects that diminish as a function of geodesic distance and time interval, and we estimate typical time scales for repeat crimes in Chicago.

Large Polyglutamine Repeats Cause Muscle Degeneration in SCA17 Mice

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Shanshan Huang

2015-10-01

Full Text Available In polyglutamine (polyQ diseases, large polyQ repeats cause juvenile cases with different symptoms than those of adult-onset patients, who carry smaller expanded polyQ repeats. The mechanisms behind the differential pathology mediated by different polyQ repeat lengths remain unknown. By studying knockin mouse models of spinal cerebellar ataxia-17 (SCA17, we found that a large polyQ (105 glutamines in the TATA-box-binding protein (TBP preferentially causes muscle degeneration and reduces the expression of muscle-specific genes. Direct expression of TBP with different polyQ repeats in mouse muscle revealed that muscle degeneration is mediated only by the large polyQ repeats. Different polyQ repeats differentially alter TBP’s interaction with neuronal and muscle-specific transcription factors. As a result, the large polyQ repeat decreases the association of MyoD with TBP and DNA promoters. Our findings suggest that specific alterations in protein interactions by large polyQ repeats may account for the unique pathology in juvenile polyQ diseases.

Large Polyglutamine Repeats Cause Muscle Degeneration in SCA17 Mice

Science.gov (United States)

Huang, Shanshan; Yang, Su; Guo, Jifeng; Yan, Sen; Gaertig, Marta A.; Li, Shihua; Li, Xiao-Jiang

2015-01-01

SUMMARY In polyglutamine (polyQ) diseases, large polyQ repeats cause juvenile cases with different symptoms than adult-onset patients, who carry smaller expanded polyQ repeats. The mechanisms behind the differential pathology mediated by different polyQ repeat lengths remain unknown. By studying knock-in mouse models of spinal cerebellar ataxia-17 (SCA17), we found that a large polyQ (105 glutamines) in the TATA box-binding protein (TBP) preferentially causes muscle degeneration and reduces the expression of muscle-specific genes. Direct expression of TBP with different polyQ repeats in mouse muscle revealed that muscle degeneration is mediated only by the large polyQ repeats. Different polyQ repeats differentially alter TBP’s interaction with neuronal and muscle-specific transcription factors. As a result, the large polyQ repeat decreases the association of MyoD with TBP and DNA promoters. Our findings suggest that specific alterations in protein interactions by large polyQ repeats may account for the unique pathology in juvenile polyQ diseases. PMID:26387956

Giant panda (Ailuropoda melanoleuca) sperm morphometry and function after repeated freezing and thawing.

Science.gov (United States)

Santiago-Moreno, J; Esteso, M C; Pradiee, J; Castaño, C; Toledano-Díaz, A; O'Brien, E; Lopez-Sebastián, A; Martínez-Nevado, E; Delclaux, M; Fernández-Morán, J; Zhihe, Z

2016-05-01

This work examines the effects of subsequent cycles of freezing-thawing on giant panda (Ailuropoda melanoleuca) sperm morphometry and function, and assesses whether density-gradient centrifugation (DGC) can increase the number of freezing-thawing cycles this sperm can withstand. A sperm sample was collected by electroejaculation from a mature giant panda and subjected to five freezing-thawing cycles. Although repeated freezing-thawing negatively affected (P 60% of the sperm cells in both treatments showed acrosome integrity even after the fifth freezing cycle. In fresh semen, the sperm head length was 4.7 μm, the head width 3.6 μm, area 14.3 μm(2) and perimeter length 14.1 μm. The present results suggest that giant panda sperm trends to be resistant to repeated freezing-thawing, even without DGC selection. © 2015 Blackwell Verlag GmbH.

A repeating fast radio burst.

Science.gov (United States)

Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

2016-03-10

Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

RTEL1 inhibits trinucleotide repeat expansions and fragility.

Science.gov (United States)

Frizzell, Aisling; Nguyen, Jennifer H G; Petalcorin, Mark I R; Turner, Katherine D; Boulton, Simon J; Freudenreich, Catherine H; Lahue, Robert S

2014-03-13

Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG) repeat expansions and fragility, likely by unwinding problematic hairpins. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Contraceptive Use among Women Seeking Repeat Abortion in ...

African Journals Online (AJOL)

AJRH Managing Editor

Compared with women seeking their first abortion, significantly more repeat abortion clients had ever used contraceptives ... findings, the level of repeat abortions in Europe, .... and contraceptive history, and post-abortion ..... working women.

Environmental stress induces trinucleotide repeat mutagenesis in human cells.

Science.gov (United States)

Chatterjee, Nimrat; Lin, Yunfu; Santillan, Beatriz A; Yotnda, Patricia; Wilson, John H

2015-03-24

The dynamic mutability of microsatellite repeats is implicated in the modification of gene function and disease phenotype. Studies of the enhanced instability of long trinucleotide repeats (TNRs)-the cause of multiple human diseases-have revealed a remarkable complexity of mutagenic mechanisms. Here, we show that cold, heat, hypoxic, and oxidative stresses induce mutagenesis of a long CAG repeat tract in human cells. We show that stress-response factors mediate the stress-induced mutagenesis (SIM) of CAG repeats. We show further that SIM of CAG repeats does not involve mismatch repair, nucleotide excision repair, or transcription, processes that are known to promote TNR mutagenesis in other pathways of instability. Instead, we find that these stresses stimulate DNA rereplication, increasing the proportion of cells with >4 C-value (C) DNA content. Knockdown of the replication origin-licensing factor CDT1 eliminates both stress-induced rereplication and CAG repeat mutagenesis. In addition, direct induction of rereplication in the absence of stress also increases the proportion of cells with >4C DNA content and promotes repeat mutagenesis. Thus, environmental stress triggers a unique pathway for TNR mutagenesis that likely is mediated by DNA rereplication. This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential.

Oxidative stress adaptation with acute, chronic, and repeated stress.

Science.gov (United States)

Pickering, Andrew M; Vojtovich, Lesya; Tower, John; A Davies, Kelvin J

2013-02-01

Oxidative stress adaptation, or hormesis, is an important mechanism by which cells and organisms respond to, and cope with, environmental and physiological shifts in the level of oxidative stress. Most studies of oxidative stress adaption have been limited to adaptation induced by acute stress. In contrast, many if not most environmental and physiological stresses are either repeated or chronic. In this study we find that both cultured mammalian cells and the fruit fly Drosophila melanogaster are capable of adapting to chronic or repeated stress by upregulating protective systems, such as their proteasomal proteolytic capacity to remove oxidized proteins. Repeated stress adaptation resulted in significant extension of adaptive responses. Repeated stresses must occur at sufficiently long intervals, however (12-h or more for MEF cells and 7 days or more for flies), for adaptation to be successful, and the levels of both repeated and chronic stress must be lower than is optimal for adaptation to acute stress. Regrettably, regimens of adaptation to both repeated and chronic stress that were successful for short-term survival in Drosophila nevertheless also caused significant reductions in life span for the flies. Thus, although both repeated and chronic stress can be tolerated, they may result in a shorter life. Copyright © 2012 Elsevier Inc. All rights reserved.

Pediatric Emergency Department Suicidal Patients: Two-Site Evaluation of Suicide Ideators, Single Attempters, and Repeat Attempters

Science.gov (United States)

Asarnow, Joan Rosenbaum; Baraff, Larry J.; Berk, Michele; Grob, Charles; Devich-Navarro, Mona; Suddath, Robert; Piacentini, John; Tang, Lingqi

2008-01-01

The study examines ideators, single attempters, and repeats attempters of suicide to clarify optimal strategies for emergency department management and risk assessment to help them in reducing youth suicide and suicide attempts. Depression was found to be a strong predictor of suicide/suicide attempts along with substance use, externalizing…

To be so bold: boldness is repeatable and related to within individual behavioural variability in North Island robins.

Science.gov (United States)

He, Ruchuan; Pagani-Núñez, Emilio; Chevallier, Clément; Barnett, Craig R A

2017-07-01

Behavioural research traditionally focusses on the mean responses of a group of individuals rather than variation in behaviour around the mean or among individuals. However, examining the variation in behaviour among and within individuals may also yield important insights into the evolution and maintenance of behaviour. Repeatability is the most commonly used measure of variability among individuals in behavioural research. However, there are other forms of variation within populations that have received less attention. One such measure is intraindividual variation in behaviour (IIV), which is a short-term fluctuation of within-individual behaviour. Such variation in behaviour might be important during interactions because it could decrease the ability of conspecific and heterospecific individuals to predict the behaviour of the subject, thus increasing the cost of the interaction. In this experiment, we made repeated measures of the latency of North Island robins to attack a prey in a novel situation (a form of boldness) and examined (i) repeatability of boldness (the propensity to take a risk), (ii) IIV of boldness, and (iii) whether there was a significant relationship between these two traits (a behavioural syndrome). We found that boldness was highly repeatable, that there were high levels of IIV in boldness, and that there was a negative relationship between boldness and IIV in boldness. This suggests that despite high levels of repeatability for this behaviour, there were also still significant differences in IIV among different individuals within the population. Moreover, bolder individuals had significantly less IIV in their boldness, which suggests that they were forming routines (which reduces behavioural variability) compared to shyer individuals. Our results definitively demonstrate that IIV itself varies across individuals and is linked with key behavioural traits, and we argue for the importance of future studies aimed at understanding its causes

Intra-operative fiducial-based CT/fluoroscope image registration framework for image-guided robot-assisted joint fracture surgery.

Science.gov (United States)

Dagnino, Giulio; Georgilas, Ioannis; Morad, Samir; Gibbons, Peter; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

2017-08-01

Joint fractures must be accurately reduced minimising soft tissue damages to avoid negative surgical outcomes. To this regard, we have developed the RAFS surgical system, which allows the percutaneous reduction of intra-articular fractures and provides intra-operative real-time 3D image guidance to the surgeon. Earlier experiments showed the effectiveness of the RAFS system on phantoms, but also key issues which precluded its use in a clinical application. This work proposes a redesign of the RAFS's navigation system overcoming the earlier version's issues, aiming to move the RAFS system into a surgical environment. The navigation system is improved through an image registration framework allowing the intra-operative registration between pre-operative CT images and intra-operative fluoroscopic images of a fractured bone using a custom-made fiducial marker. The objective of the registration is to estimate the relative pose between a bone fragment and an orthopaedic manipulation pin inserted into it intra-operatively. The actual pose of the bone fragment can be updated in real time using an optical tracker, enabling the image guidance. Experiments on phantom and cadavers demonstrated the accuracy and reliability of the registration framework, showing a reduction accuracy (sTRE) of about [Formula: see text] (phantom) and [Formula: see text] (cadavers). Four distal femur fractures were successfully reduced in cadaveric specimens using the improved navigation system and the RAFS system following the new clinical workflow (reduction error [Formula: see text], [Formula: see text]. Experiments showed the feasibility of the image registration framework. It was successfully integrated into the navigation system, allowing the use of the RAFS system in a realistic surgical application.

Training Distal Locking Screw Insertion Skills to Novice Trainees: A Comparison Between Fluoroscopic- and Electromagnetic-Guided Techniques.

Science.gov (United States)

Leroux, Timothy; Khoshbin, Amir; Nousiainen, Markku T

2015-10-01

To compare the effect fluoroscopy or electromagnetic (EM) guidance has on the learning of locking screw insertion in tibial nails in surgical novices. A randomized, prospective, controlled trial was conducted involving 18 surgical trainees with no prior experience inserting locking screws in intramedullary nails. After a training session using fluoroscopy, participants underwent a pretest using fluoroscopic guidance. Participants were then randomized into either the fluoroscopy or EM group and were further trained using their respective technique. Post, retention, and transfer tests were conducted. Outcomes included task completion, drill attempts, screw changes, and radiation time. Intragroup comparisons revealed that the EM group used significantly less drill attempts during the post and retention tests compared with the pretest (P = 0.016 and P = 0.016, respectively). Intergroup comparisons revealed that the EM group was (1) more likely to complete the task during the retention test (P = 0.043) and (2) had significantly less radiation time during the post and retention tests (P = 0.002 and P = 0.003, respectively). Radiation time in the EM group during the transfer test increased to a level equal to what the fluoroscopy group used during the post and retention tests (P = 0.71 and P = 0.92, respectively). No other significant between-group differences occurred. EM guidance may be safely used to assist in the training of surgical novices in the skill of distal locking screw insertion. Not only does this technology significantly improve the ability to complete the task and decrease radiation use but also it does so without compromising skill acquisition. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

The repeatability of interleukin-6, tumor necrosis factor-alpha, and C-reactive protein in COPD patients over one year

DEFF Research Database (Denmark)

Kolsum, Umme; Roy, Kay; Starkey, Cerys

2009-01-01

BACKGROUND: Many of the systemic manifestations of chronic obstructive pulmonary disease (COPD) are mediated through increased systemic levels of inflammatory proteins. We assessed the long term repeatability of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein......(i)) and the Bland-Altman method. Pearson correlations were used to determine the relationships between the systemic markers at both visits. RESULTS: There was moderate repeatability with a very high degree of statistical significance (p...... (CRP) over one year and examined the relationships between these systemic markers in COPD. METHODS: Fifty-eight stable COPD patients completed a baseline and one-year visit. Serum IL-6, plasma CRP, and plasma TNF-alpha were measured. Repeatability was expressed by intraclass correlation coefficient (R...

The repeatability of interleukin-6, tumor necrosis factor-alpha, and C-reactive protein in COPD patients over one year

DEFF Research Database (Denmark)

Kolsum, Umme; Roy, Kay; Starkey, Cerys

2009-01-01

BACKGROUND: Many of the systemic manifestations of chronic obstructive pulmonary disease (COPD) are mediated through increased systemic levels of inflammatory proteins. We assessed the long term repeatability of Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein......(i)) and the Bland-Altman method. Pearson correlations were used to determine the relationships between the systemic markers at both visits. RESULTS: There was moderate repeatability with a very high degree of statistical significance (p...... (CRP) over one year and examined the relationships between these systemic markers in COPD. METHODS: Fifty-eight stable COPD patients completed a baseline and one-year visit. Serum IL-6, plasma CRP, and plasma TNF-alpha were measured. Repeatability was expressed by intraclass correlation coefficient (R...

The effectiveness of immediate feedback during the objective structured clinical examination.

Science.gov (United States)

Hodder, R V; Rivington, R N; Calcutt, L E; Hart, I R

1989-03-01

Using eight different physical examination or technical stations, 400 examinations were conducted to evaluate the effectiveness of immediate feedback during the Objective Structured Clinical Examination (OSCE). The test group comprised 50 medical students who underwent a standard 4-minute examination followed by 2 minutes of feedback. Immediately following feedback the students repeated an identical 4-minute examination scored by the same examiners. The control group consisted of 50 students from the same class who underwent an identical testing sequence, but instead of receiving feedback, they were instructed to continue their examinations for an additional 2 minutes before repeating the stations. Simple repetition of the task did not significantly improve score (mean increase 2.0%, NS). Extending the testing period from 4 to 6 minutes resulted in a small but significant increase in score (mean 6.7%, P less than 0.001). However, there was a much larger increase in the scores obtained following 2 minutes of immediate feedback compared to pre-feedback performance (mean 26.3%, P less than 0.0001). The majority of students and examiners felt that feedback, as administered in this study, was valuable both as a learning and teaching experience. Short periods of immediate feedback during an OSCE are practical and can improve competency in the performance of criterion-based tasks, at least over the short term. In addition, such feedback provides students with valuable self-assessment that may stimulate further learning.

Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

International Nuclear Information System (INIS)

Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

2011-01-01

Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80–90). The mean retreatment dose was 84.4 Gy (range, 60–90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

Energy Technology Data Exchange (ETDEWEB)

Aubuchon, Adam C., E-mail: acaubuchon@gmail.com [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Chan, Michael D. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Lovato, James F. [Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Balamucki, Christopher J. [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ellis, Thomas L.; Tatter, Stephen B. [Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, NC (United States); McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States)

2011-11-15

Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

Effect of heavy back squats on repeated sprint performance in trained men.

Science.gov (United States)

Duncan, M J; Thurgood, G; Oxford, S W

2014-04-01

This study examined the impact of post activation potentiation on repeated sprint performance in trained Rugby Union players. Ten, male, professional Rugby Union players (mean age=25.2±5.02 years) performed 7, 30-meter sprints, separated by 25 seconds, 4 minutes following back squats (90% 1 repetition maximum) or a control condition performed in a counterbalanced order. Significant condition X sprint interactions for 10-meter (P=0.02) and 30-meter (P=0.05) indicated that times were significantly faster in the PAP condition for sprints 5, 6 and 7 across both distances. Fatigue rate was also significantly lower in the PAP condition for 10-meter (P=0.023) and 30-meter (P=0.006) sprint running speed. This study evidences that a heavy resistance exercise stimulus administered four minutes prior to repeated sprints can offset the decline in sprint performance seen during subsequent maximal sprinting over 10 and 30-meters in Rugby Union players.

Repeat Assessed Values Model for Housing Price Index

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Carini Manuela

2017-12-01

Full Text Available This study proposes an innovative methodology, named Repeat Appraised Price Model (RAV, useful for determining the price index numbers for real estate markets and the corresponding index numbers of hedonic prices of main real estate characteristics in the case of a lack of data. The methodological approach proposed in this paper aims to appraise the time series of price index numbers. It integrates the principles of the method of repeat sales with the peculiarities of the Hedonic Price Method, overcoming the problem of an almost total absence of repeat sales for the same property in a given time range; on the other hand, the technique aims to overcome the limitation of the repeat sales technique concerning the inability to take into account the characteristics of individual properties.

Detection of organ movement in cervix cancer patients using a fluoroscopic electronic portal imaging device and radiopaque markers

International Nuclear Information System (INIS)

Kaatee, Robert S.J.P.; Olofsen, Manouk J.J.; Verstraate, Marjolein B.J.; Quint, Sandra; Heijmen, Ben J.M.

2002-01-01

Purpose: To investigate the use of a fluoroscopic electronic portal imaging device (EPID) and radiopaque markers to detect internal cervix movement. Methods and Materials: For 10 patients with radiopaque markers clamped to the cervix, electronic portal images were made during external beam irradiation. Bony structures and markers in the portal images were registered with the same structures in the corresponding digitally reconstructed radiographs of the planning computed tomogram. Results: The visibility of the markers in the portal images was good, but their fixation should be improved. Generally, the correlation between bony structure displacements and marker movement was poor, the latter being substantially larger. The standard deviations describing the systematic and random bony anatomy displacements were 1.2 and 2.6 mm, 1.7 and 2.9 mm, and 1.6 and 2.7 mm in the lateral, cranial-caudal, and dorsal-ventral directions, respectively. For the marker movement those values were 3.4 and 3.4 mm, 4.3 and 5.2 mm, 3.2 and 5.2 mm, respectively. Estimated clinical target volume to planning target volume (CTV-PTV) planning margins (∼11 mm) based on the observed overall marker displacements (bony anatomy + internal cervix movement) are only marginally larger than the margins required to account for internal marker movement alone. Conclusions: With our current patient setup techniques and methods of setup verification and correction, the required CTV-PTV margins are almost fully determined by internal organ motion. Setup verification and correction using radiopaque markers might allow decreasing those margins, but technical improvements are needed

Heat stress impairs repeated jump ability after competitive elite soccer games

DEFF Research Database (Denmark)

Mohr, Magni; Krustrup, Peter

2013-01-01

ABSTRACT:: The present study examined the effect of environmental heat stress on repeated jump performance after elite competitive soccer games. Male elite soccer players (n=19) from two Scandinavian teams participated (age; 26.7±1.0 yrs, height; 181.7±1.1 cm, body mass; 75.8±1.0 kg). The players...... had a Yo-Yo IR2 performance of 1032±42 m (range: 920-1400 m). The players took part in the Champions League Qualification (CL), where six games (three home and three away) were played. The home games took place at an average ambient temperature of 12.2±0.5 oC (control game; CON) and the away games...... in hot conditions (30.0±0.3 oC; HOT). In resting condition (Baseline) and immediately after CON and HOT, the players performed a repeated countermovement jump (CMJ) test consisting of five jumps separated by 10 s of recovery. Game-induced body mass loss was determined based on change in body mass after...

Comparative and functional characterization of intragenic tandem repeats in 10 Aspergillus genomes.

Science.gov (United States)

Gibbons, John G; Rokas, Antonis

2009-03-01

Intragenic tandem repeats (ITRs) are consecutive repeats of three or more nucleotides found in coding regions. ITRs are the underlying cause of several human genetic diseases and have been associated with phenotypic variation, including pathogenesis, in several clades of the tree of life. We have examined the evolution and functional role of ITRs in 10 genomes spanning the fungal genus Aspergillus, a clade of relevance to medicine, agriculture, and industry. We identified several hundred ITRs in each of the species examined. ITR content varied extensively between species, with an average 79% of ITRs unique to a given species. For the fraction of conserved ITR regions, sequence comparisons within species and between close relatives revealed that they were highly variable. ITR-containing proteins were evolutionarily less conserved, compositionally distinct, and overrepresented for domains associated with cell-surface localization and function relative to the rest of the proteome. Furthermore, ITRs were preferentially found in proteins involved in transcription, cellular communication, and cell-type differentiation but were underrepresented in proteins involved in metabolism and energy. Importantly, although ITRs were evolutionarily labile, their functional associations appeared. To be remarkably conserved across eukaryotes. Fungal ITRs likely participate in a variety of developmental processes and cell-surface-associated functions, suggesting that their contribution to fungal lifestyle and evolution may be more general than previously assumed.

Reproducibility and Reliability of Repeated Quantitative Fluorescence Angiography

DEFF Research Database (Denmark)

Nerup, Nikolaj; Knudsen, Kristine Bach Korsholm; Ambrus, Rikard

2017-01-01

INTRODUCTION: When using fluorescence angiography (FA) in perioperative perfusion assessment, repeated measures with re-injections of fluorescent dye (ICG) may be required. However, repeated injections may cause saturation of dye in the tissue, exceeding the limit of fluorescence intensity...... that the camera can detect. As the emission of fluorescence is dependent of the excitatory light intensity, reduction of this may solve the problem. The aim of the present study was to investigate the reproducibility and reliability of repeated quantitative FA during a reduction of excitatory light....

Clinical oversight and the avoidance of repeat induced abortion.

Science.gov (United States)

Jacovetty, Erica L; Clare, Camille A; Squire, Mary-Beatrice; Kubal, Keshar P; Liou, Sherry; Inchiosa, Mario A

2018-06-03

To evaluate the impact of patient counseling, demographics, and contraceptive methods on repeat induced abortion in women attending family planning clinics. A retrospective chart review of repeat induced abortions was performed. The analysis included patients with an initial induced abortion obtained between January 1, 2001, and March 31, 2014, at New York City Health + Hospitals/Metropolitan. The duration of involvement in the family planning program, the use of contraceptive interventions, and 18 patient factors were analyzed for their correlation with the incidence of repeat induced abortions per year of follow-up. A decreased rate of repeat induced abortions was associated with a longer duration of clinical oversight (r 2 =0.449, Pabortions. By determining the patient characteristics that most influence repeat induced abortion rates, providers can best choose the most efficacious method of contraception available. © 2018 International Federation of Gynecology and Obstetrics.

Effect of repeated small-dose γ-ray irradiation on atopic dermatitis in NC/Nga mice

International Nuclear Information System (INIS)

Fang, Su-Ping; Muto, Yasuko; Tago, Fumitoshi; Simura, Noriko; Kojima, Shuji

2006-01-01

We previously showed that several small-dose 0.5 Gy whole-body γ-ray irradiation inhibits tumor growth in mice via elevation of the interferon (IFN)-γ/interleukin 4 (IL-4) ratio concomitantly with a decrease in the percentage of B cells. Here, we examined whether repeated small-dose (0.5 Gy, 10 times) γ-ray irradiation influences atopic dermatitis in an NC/Nga mouse model. It was found that repeated γ-ray irradiation increased total IgE in comparison with the disease-control group. Levels of IL-4 and IL-5 were increased versus the disease-control group, while IFN-γ was slightly decreased, resulting in a further decrease of the IFN-γ/IL-4 ratio compared with the disease-control group. These results indicate that repeated small-dose γ-ray irradiation may exacerbate atopic dermatitis. This may be because the irradiation induces not helper T lymphocyte 1 (Th1), but Th2 polarization in this atopic mouse model, i.e., the effects of small-dose irradiation may be different in conditions involving immune hypersensitivity and impaired immunity. (author)

Determinants and Experiences of Repeat Pregnancy among HIV-Positive Kenyan Women--A Mixed-Methods Analysis.

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Victor Akelo

Full Text Available To identify factors associated with repeat pregnancy subsequent to an index pregnancy among women living with HIV (WLWH in western Kenya who were enrolled in a 24-month phase-II clinical trial of triple-ART prophylaxis for prevention of mother-to-child transmission, and to contextualize social and cultural influences on WLWH's reproductive decision making.A mixed-methods approach was used to examine repeat pregnancy within a 24 month period after birth. Counselor-administered questionnaires were collected from 500 WLWH. Forty women (22 with a repeat pregnancy; 18 with no repeat pregnancy were purposively selected for a qualitative interview (QI. Simple and multiple logistic regression analyses were performed for quantitative data. Thematic coding and saliency analysis were undertaken for qualitative data.Eighty-eight (17.6% women had a repeat pregnancy. Median maternal age was 23 years (range 15-43 years and median gestational age at enrollment was 34 weeks. In multiple logistic regression analyses, living in the same compound with a husband (adjusted odds ratio (AOR: 2.33; 95% confidence interval (CI: 1.14, 4.75 was associated with increased odds of repeat pregnancy (p ≤ 0.05. Being in the 30-43 age group (AOR: 0.25; 95% CI: 0.07, 0.87, having talked to a partner about family planning (FP use (AOR: 0.53; 95% CI: 0.29, 0.98, and prior usage of FP (AOR: 0.45; 95% CI: 0.25, 0.82 were associated with a decrease in odds of repeat pregnancy. QI findings centered on concerns about modern contraception methods (side effects and views that they 'ruined the womb' and a desire to have the right number of children. Religious leaders, family, and the broader community were viewed as reinforcing cultural expectations for married women to have children. Repeat pregnancy was commonly attributed to contraception failure or to lack of knowledge about post-delivery fertility.In addition to cultural context, reproductive health programs for WLWH may need to

A versatile palindromic amphipathic repeat coding sequence horizontally distributed among diverse bacterial and eucaryotic microbes

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Glass John I

2010-07-01

Full Text Available Abstract Background Intragenic tandem repeats occur throughout all domains of life and impart functional and structural variability to diverse translation products. Repeat proteins confer distinctive surface phenotypes to many unicellular organisms, including those with minimal genomes such as the wall-less bacterial monoderms, Mollicutes. One such repeat pattern in this clade is distributed in a manner suggesting its exchange by horizontal gene transfer (HGT. Expanding genome sequence databases reveal the pattern in a widening range of bacteria, and recently among eucaryotic microbes. We examined the genomic flux and consequences of the motif by determining its distribution, predicted structural features and association with membrane-targeted proteins. Results Using a refined hidden Markov model, we document a 25-residue protein sequence motif tandemly arrayed in variable-number repeats in ORFs lacking assigned functions. It appears sporadically in unicellular microbes from disparate bacterial and eucaryotic clades, representing diverse lifestyles and ecological niches that include host parasitic, marine and extreme environments. Tracts of the repeats predict a malleable configuration of recurring domains, with conserved hydrophobic residues forming an amphipathic secondary structure in which hydrophilic residues endow extensive sequence variation. Many ORFs with these domains also have membrane-targeting sequences that predict assorted topologies; others may comprise reservoirs of sequence variants. We demonstrate expressed variants among surface lipoproteins that distinguish closely related animal pathogens belonging to a subgroup of the Mollicutes. DNA sequences encoding the tandem domains display dyad symmetry. Moreover, in some taxa the domains occur in ORFs selectively associated with mobile elements. These features, a punctate phylogenetic distribution, and different patterns of dispersal in genomes of related taxa, suggest that the

Tandem repeat regions within the Burkholderia pseudomallei genome and their application for high resolution genotyping

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Harvey Steven P

2007-03-01

Full Text Available Abstract Background The facultative, intracellular bacterium Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine 66 B. pseudomallei and 21 B. mallei isolates from around the world, as well as 95 lineages from a serial transfer experiment encompassing ~18,000 generations. Results B. pseudomallei contains a preponderance of tandem repeat loci throughout its genome, many of which are duplicated elsewhere in the genome. The majority of these loci are composed of repeat motif lengths of 6 to 9 bp with 4 to 10 repeat units and are predominately located in intergenic regions of the genome. Across geographically diverse B. pseudomallei and B.mallei isolates, the 32 VNTR loci displayed between 7 and 28 alleles, with Nei's diversity values ranging from 0.47 and 0.94. Mutation rates for these loci are comparable (>10-5 per locus per generation to that of the most diverse tandemly repeated regions found in other less diverse bacteria. Conclusion The frequency, location and duplicate nature of tandemly repeated regions within the B. pseudomallei genome indicate that these tandem repeat regions may play a role in generating and maintaining adaptive genomic variation. Multiple-locus VNTR analysis revealed extensive diversity within the global isolate set containing B. pseudomallei and B. mallei, and it detected genotypic differences within clonal lineages of both species that were

Mood and autonomic responses to repeated exposure to the Trier Social Stress Test for Groups (TSST-G).

Science.gov (United States)

Boesch, Maria; Sefidan, Sandra; Ehlert, Ulrike; Annen, Hubert; Wyss, Thomas; Steptoe, Andrew; La Marca, Roberto

2014-05-01

A group version of the Trier Social Stress Test (TSST-G) was introduced as a standardized, economic and efficient tool to induce a psychobiological stress response simultaneously in a group of subjects. The aim of the present study was to examine the efficacy of the TSST-G to repeatedly induce an affective and autonomic stress response while comparing two alternative protocols for the second examination. Healthy young male recruits participated twice in the TSST-G 10 weeks apart. In the first examination, the TSST-G consisted of a combination of mental arithmetic and a fake job interview (TSST-G-1st; n=294). For the second examination, mental arithmetic was combined with either (a) a defensive speech in response to a false shoplifting accusation (TSST-G-2nd-defence; n=105), or (b) a speech on a more neutral topic selected by the investigators (TSST-G-2nd-presentation; n=100). Affect ratings and salivary alpha-amylase (sAA) were determined immediately before and after the stress test, while heart rate (HR) and heart rate variability (HRV) were measured continuously. TSST-G-1st resulted in a significant increase of negative affect, HR, and sAA, and a significant decrease in positive affect and HRV. TSST-G-2nd, overall, resulted in a significant increase of HR and sAA (the latter only in response to TSST-G-2nd-defence) and a decrease in HRV, while no significant affect alterations were found. When comparing both, TSST-G-2nd-defence and -2nd-presentation, the former resulted in a stronger stress response with regard to HR and HRV. The findings reveal that the TSST-G is a useful protocol to repeatedly evoke an affective and autonomic stress response, while repetition leads to affective but not necessarily autonomic habituation. When interested in examining repeated psychosocial stress reactivity, a task that requires an ego-involving effort, such as a defensive speech, seems to be significantly superior to a task using an impersonal speech. Copyright © 2014 Elsevier

Repeatability of a 3D multi-segment foot model during anterior and lateral step down tests.

Science.gov (United States)

Lucareli, Paulo Roberto Garcia; Contani, Luciane Beatriz Grohs; Lima, Bruna; Rabelo, Nayra Deise dos Anjos; Ferreira, Cintia Lopes; Lima, Fernanda Pulpio Silva; Correa, João Carlos Ferrari; Politti, Fabiano

2016-01-01

The aim of the present study was to analyse the reproducibility of the Oxford Foot Model (OFM) when used with healthy adults during two clinical tests, i.e., the Anterior Step Down Test (SDA) and the Lateral Step Down Test (SDL). Five healthy participants (one male and four females, 10 limbs in total) with a mean age of 22.2 (19-30) years were assessed in four sessions of tests conducted at intervals of one week. Two independent examiners performed two of the sessions of each of the tests. For each session (intra-day), nine repetitions of each clinical test (SDA and SDL) were performed. After an interval of three hours, the data were collected again. The tests were conducted again after an interval of one week using the same experimental conditions. The intra- and inter-session repeatabilities of the ranges of motion of the feet were determined according to the standard error of measurement (SEM) for each examiner and for the differences between the examiners. The repeatabilities of the results were high for both of the conducted tests. The SEM results were as follows: 0.47-1.94° for the intra-examiner assessment (SDA), 0.55-2.01° for the inter-examiner comparison (SDA), 0.44-2.43° for the intra-examiner assessment (SDL), and 0.54-1.89° for the inter-examiner comparison (SDL). The OFM model was shown to be reproducible in terms of assessing the range of motion of healthy adults during functional tests (SDA and SDL). Copyright © 2015 Elsevier B.V. All rights reserved.

A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally.

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Michelle R Newman

Full Text Available The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1, B1 and Intracisternal-A-Particle (IAP repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen and a tissue fundamental to the aging process (liver. Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA

Repeated episodes of chronic intermittent ethanol promote insensitivity to devaluation of the reinforcing effect of ethanol.

Science.gov (United States)

Lopez, M F; Becker, H C; Chandler, L J

2014-11-01

Studies in animal models have shown that repeated episodes of alcohol dependence and withdrawal promote escalation of drinking that is presumably associated with alterations in the addiction neurocircuitry. Using a lithium chloride-ethanol pairing procedure to devalue the reinforcing properties of ethanol, the present study determined whether multiple cycles of chronic intermittent ethanol (CIE) exposure by vapor inhalation also alters the sensitivity of drinking behavior to the devaluation of ethanol's reinforcing effects. The effect of devaluation on operant ethanol self-administration and extinction was examined in mice prior to initiation of CIE (short drinking history) and after repeated cycles of CIE or air control exposure (long drinking history). Devaluation significantly attenuated the recovery of baseline ethanol self-administration when tested either prior to CIE or in the air-exposed controls that had experienced repeated bouts of drinking but no CIE. In contrast, in mice that had undergone repeated cycles of CIE exposure that promoted escalation of ethanol drinking, self-administration was completely resistant to the effect of devaluation. Devaluation had no effect on the time course of extinction training in either pre-CIE or post-CIE mice. Taken together, these results are consistent with the suggestion that repeated cycles of ethanol dependence and withdrawal produce escalation of ethanol self-administration that is associated with a change in sensitivity to devaluation of the reinforcing properties of ethanol. Copyright © 2014 Elsevier Inc. All rights reserved.

Methods for analysing cardiovascular studies with repeated measures

NARCIS (Netherlands)

Cleophas, T. J.; Zwinderman, A. H.; van Ouwerkerk, B. M.

2009-01-01

Background. Repeated measurements in a single subject are generally more similar than unrepeated measurements in different subjects. Unrepeated analyses of repeated data cause underestimation of the treatment effects. Objective. To review methods adequate for the analysis of cardiovascular studies

TALEN-Induced Double-Strand Break Repair of CTG Trinucleotide Repeats

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Valentine Mosbach

2018-02-01

Full Text Available Trinucleotide repeat expansions involving CTG/CAG triplets are responsible for several neurodegenerative disorders, including myotonic dystrophy and Huntington’s disease. Because expansions trigger the disease, contracting repeat length could be a possible approach to gene therapy for these disorders. Here, we show that a TALEN-induced double-strand break was very efficient at contracting expanded CTG repeats in yeast. We show that RAD51, POL32, and DNL4 are dispensable for double-strand break repair within CTG repeats, the only required genes being RAD50, SAE2, and RAD52. Resection was totally abolished in the absence of RAD50 on both sides of the break, whereas it was reduced in a sae2Δ mutant on the side of the break containing the longest repeat tract, suggesting that secondary structures at double-strand break ends must be removed by the Mre11-Rad50 complex and Sae2. Following the TALEN double-strand break, single-strand annealing occurred between both sides of the repeat tract, leading to repeat contraction.

In silico reversal of repeat-induced point mutation (RIP identifies the origins of repeat families and uncovers obscured duplicated genes

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Hane James K

2010-11-01

Full Text Available Abstract Background Repeat-induced point mutation (RIP is a fungal genome defence mechanism guarding against transposon invasion. RIP mutates the sequence of repeated DNA and over time renders the affected regions unrecognisable by similarity search tools such as BLAST. Results DeRIP is a new software tool developed to predict the original sequence of a RIP-mutated region prior to the occurrence of RIP. In this study, we apply deRIP to the genome of the wheat pathogen Stagonospora nodorum SN15 and predict the origin of several previously uncharacterised classes of repetitive DNA. Conclusions Five new classes of transposon repeats and four classes of endogenous gene repeats were identified after deRIP. The deRIP process is a new tool for fungal genomics that facilitates the identification and understanding of the role and origin of fungal repetitive DNA. DeRIP is open-source and is available as part of the RIPCAL suite at http://www.sourceforge.net/projects/ripcal.

Use of the Counseling Center Assessment of Psychological Symptoms 62 (CCAPS-62) as a Repeated Measure

Science.gov (United States)

Ghosh, Arpita; Rieder Bennett, Sara; Martin, Juanita K.

2018-01-01

The purpose of this initial, exploratory study was to examine the utility of the Counseling Center Assessment of Psychological Symptoms-62 (CCAPS-62) as a repeated measure tool at one university counseling center. This study investigated whether clients engaged in individual counseling changed in symptomology while in treatment and when (e.g.,…

Examining demographic and situational factors on animal cruelty motivations.

Science.gov (United States)

Hensley, Christopher; Tallichet, Suzanne E; Dutkiewicz, Erik L

2011-05-01

Because of the limited number of studies that have examined the motives for childhood animal cruelty, researchers continue to suggest that further systematic study is needed. In a replication of the Hensley and Tallichet study and based on survey data from 180 inmates at one medium- and one maximum-security prison in a southern U.S. state, the present study seeks to further develop this understanding by examining the impact of demographic and situational factors on a range of animal cruelty motivations. Of the 180 inmates, 103 (57%) committed acts of animal cruelty. Logistic regression analyses revealed that respondents who committed childhood animal cruelty out of anger were less likely to cover up their behavior and to be upset by their actions but were more likely to have repeated it. Those who committed animal cruelty to shock others were more likely to reside in urban areas and to have done it alone. Furthermore, respondents who committed animal cruelty for sexual reasons were more likely to have covered up their actions and to have engaged in it repeatedly.

A Dual Repeat Cis-Element Determines Expression of GERANYL DIPHOSPHATE SYNTHASE for Monoterpene Production in Phalaenopsis Orchids

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Yu-Chen Chuang

2018-06-01

Full Text Available Phalaenopsis bellina is a scented orchid emitting large amount of monoterpenes. GERANYL DIPHOSPHATE SYNTHASE (PbGDPS is the key enzyme for monoterpene biosynthesis, and shows concomitant expression with the emission of monoterpenes during flower development in P. bellina. Here, we identified a dual repeat cis-element in the GDPS promoter that is critical for monoterpene biosynthesis in Phalaenopsis orchids. A strong correlation between the dual repeat and the monoterpene production was revealed by examination of the GDPS promoter fragments over 12 Phalaenopsis species. Serial-deletion of the 2-kb GDPS promoter fragments demonstrated that the integrity of the dual repeat was crucial for its promoter activities. By screening the Arabidopsis transcription factors (TFs cDNA library using yeast one-hybrid assay, AtbZIP18, a member of group I of bZIP TFs, was identified to be able to bind the dual repeat. We then identified PbbZIP4 in the transcriptome of P. bellina, showing 83% identity in the DNA binding region with that of AtbZIP18, and the expression level of PbbZIP4 was higher in the scented orchids. In addition, PbbZIP4 transactivated the GDPS promoter fragment containing the dual repeat in dual luciferase assay. Furthermore, transient ectopic expression of PbbZIP4 induced a 10-fold production of monoterpenoids in the scentless orchid. In conclusion, these results indicate that the dual repeat is a real TF-bound cis-element significant for GDPS gene expression, and thus subsequent monoterpene biosynthesis in the scented Phalaenopsis orchids.

simple sequence repeat (SSR)

African Journals Online (AJOL)

In the present study, 78 mapped simple sequence repeat (SSR) markers representing 11 linkage groups of adzuki bean were evaluated for transferability to mungbean and related Vigna spp. 41 markers amplified characteristic bands in at least one Vigna species. The transferability percentage across the genotypes ranged ...

Simple sequence repeat marker development and genetic mapping ...

Indian Academy of Sciences (India)

polymorphic SSR (simple sequence repeats) markers from libraries enriched for GA, CAA and AAT repeats, as well as 6 ... ers for quinoa was the development of a genetic linkage map ...... Weber J. L. 1990 Informativeness of human (dC-dA)n.

Repeating pneumatic pellet injector in JAERI

Energy Technology Data Exchange (ETDEWEB)

Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment); Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

1992-09-01

A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author).

Repeating pneumatic pellet injector in JAERI

International Nuclear Information System (INIS)

Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi; Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

1992-09-01

A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author)

Repeated mild traumatic brain injury in female rats increases lipid peroxidation in neurons.

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Yates, Nathanael J; Lydiard, Stephen; Fehily, Brooke; Weir, Gillian; Chin, Aaron; Bartlett, Carole A; Alderson, Jacqueline; Fitzgerald, Melinda

2017-07-01

Negative outcomes of mild traumatic brain injury (mTBI) can be exacerbated by repeated insult. Animal models of repeated closed-head mTBI provide the opportunity to define acute pathological mechanisms as the number of mTBI increases. Furthermore, little is known about the effects of mTBI impact site, and how this may affect brain function. We use a closed head, weight drop model of mTBI that allows head movement following impact, in adult female rats to determine the role of the number and location of mTBI on brain pathology and behaviour. Biomechanical assessment of two anatomically well-defined mTBI impact sites were used, anterior (bregma) and posterior (lambda). Location of the impact had no significant effect on impact forces (450 N), and the weight impact locations were on average 5.4 mm from the desired impact site. No between location vertical linear head kinematic differences were observed immediately following impact, however, in the 300 ms post-impact, significantly higher mean vertical head displacement and velocity were observed in the mTBI lambda trials. Breaches of the blood brain barrier were observed with three mTBI over bregma, associated with immunohistochemical indicators of damage. However, an increased incidence of hairline fractures of the skull and macroscopic haemorrhaging made bregma an unsuitable impact location to model repeated mTBI. Repeated mTBI over lambda did not cause skull fractures and were examined more comprehensively, with outcomes following one, two or three mTBI or sham, delivered at 1 day intervals, assessed on days 1-4. We observe a mild behavioural phenotype, with subtle deficits in cognitive function, associated with no identifiable neuroanatomical or inflammatory changes. However, an increase in lipid peroxidation in a subset of cortical neurons following two mTBI indicates increasing oxidative damage with repeated injury in female rats, supported by increased amyloid precursor protein immunoreactivity with three m

ACCA phosphopeptide recognition by the BRCT repeats of BRCA1.

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Ray, Hind; Moreau, Karen; Dizin, Eva; Callebaut, Isabelle; Venezia, Nicole Dalla

2006-06-16

The tumour suppressor gene BRCA1 encodes a 220 kDa protein that participates in multiple cellular processes. The BRCA1 protein contains a tandem of two BRCT repeats at its carboxy-terminal region. The majority of disease-associated BRCA1 mutations affect this region and provide to the BRCT repeats a central role in the BRCA1 tumour suppressor function. The BRCT repeats have been shown to mediate phospho-dependant protein-protein interactions. They recognize phosphorylated peptides using a recognition groove that spans both BRCT repeats. We previously identified an interaction between the tandem of BRCA1 BRCT repeats and ACCA, which was disrupted by germ line BRCA1 mutations that affect the BRCT repeats. We recently showed that BRCA1 modulates ACCA activity through its phospho-dependent binding to ACCA. To delineate the region of ACCA that is crucial for the regulation of its activity by BRCA1, we searched for potential phosphorylation sites in the ACCA sequence that might be recognized by the BRCA1 BRCT repeats. Using sequence analysis and structure modelling, we proposed the Ser1263 residue as the most favourable candidate among six residues, for recognition by the BRCA1 BRCT repeats. Using experimental approaches, such as GST pull-down assay with Bosc cells, we clearly showed that phosphorylation of only Ser1263 was essential for the interaction of ACCA with the BRCT repeats. We finally demonstrated by immunoprecipitation of ACCA in cells, that the whole BRCA1 protein interacts with ACCA when phosphorylated on Ser1263.

Repeated mapping of cortical language sites by preoperative navigated transcranial magnetic stimulation compared to repeated intraoperative DCS mapping in awake craniotomy

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2014-01-01

Background Repetitive navigated transcranial magnetic stimulation (rTMS) was recently described for mapping of human language areas. However, its capability of detecting language plasticity in brain tumor patients was not proven up to now. Thus, this study was designed to evaluate such data in order to compare rTMS language mapping to language mapping during repeated awake surgery during follow-up in patients suffering from language-eloquent gliomas. Methods Three right-handed patients with left-sided gliomas (2 opercular glioblastomas, 1 astrocytoma WHO grade III of the angular gyrus) underwent preoperative language mapping by rTMS as well as intraoperative language mapping provided via direct cortical stimulation (DCS) for initial as well as for repeated Resection 7, 10, and 15 months later. Results Overall, preoperative rTMS was able to elicit clear language errors in all mappings. A good correlation between initial rTMS and DCS results was observed. As a consequence of brain plasticity, initial DCS and rTMS findings only corresponded with the results obtained during the second examination in one out of three patients thus suggesting changes of language organization in two of our three patients. Conclusions This report points out the usefulness but also the limitations of preoperative rTMS language mapping to detect plastic changes in language function or for long-term follow-up prior to DCS even in recurrent gliomas. However, DCS still has to be regarded as gold standard. PMID:24479694

Targeted histology sampling from atypical small acinar proliferation area detected by repeat transrectal prostate biopsy

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A. V. Karman

2017-01-01

Full Text Available Оbjective: to define the approach to the management of patients with the detected ASAP area.Materials and methods. In the time period from 2012 through 2015, 494 patients with previously negative biopsy and remaining suspicion of prostate cancer (PCa were examined. The patients underwent repeat 24-core multifocal prostate biopsy with taking additional tissue samples from suspicious areas detected by multiparametric magnetic resonance imaging and transrectal ultrasound. An isolated ASAP area was found in 127 (25. 7 % of the 494 examined men. All of them were offered to perform repeat target transrectal biopsy of this area. Targeted transrectal ultrasound guided biopsy of the ASAP area was performed in 56 (44.1 % of the 127 patients, 53 of them being included in the final analysis.Results. PCa was diagnosed in 14 (26.4 % of the 53 patients, their mean age being 64.4 ± 6.9 years. The average level of prostate-specific antigen (PSA in PCa patients was 6.8 ± 3.0 ng/ml, in those with benign lesions – 9.3 ± 6.5 ng/ml; the percentage ratio of free/total PSA with PCa was 16.2 ± 7,8 %, with benign lesions – 23.3 ± 7.7 %; PSA density in PCa patients was 0.14 ± 0.07 ng/ml/cm3, in those with benign lesions – 0.15 ± 0.12 ng/ml/cm3. Therefore, with ASAP area being detected in repeat prostate biopsy samples, it is advisable that targeted extended biopsy of this area be performed. 

The diagnosis of cancer in thyroid fine needle aspiration biopsy. Surgery, repeat biopsy or specimen consultation?

Directory of Open Access Journals (Sweden)

Agata Stanek-Widera

2016-05-01

Full Text Available Fine needle aspiration biopsy (FNA is the only diagnostic method that allows a preoperative diagnosis of thyroid carcinoma. An unequivocal diagnosis of a malignant change is achievable only in cases in which all cytological criteria of carcinoma are met. The aim of the study was to evaluate the necessity of repeat thyroid FNA in patients with papillary thyroid carcinoma verified on consultative examination (CE. We analyzed cytology reports of thyroid FNA and CE that resulted in the diagnosis of papillary carcinoma. Evaluation of the correlation of the cytological diagnosis with the histopathology report was based on data obtained after the surgery. Between 2010 and 2015 in the Institute of Oncology (IO there were 184 cancers diagnosed on CE or in thyroid FNA performed primarily in IO. Additionally, 74 patients were subjected to repeat biopsy after confirmation of cancer in CE. Histopathological diagnosis of cancer was obtained in 62 (100% cases that were doubly confirmed with cytological examination. The remaining 12 patients were operated on outside the institute. From 110 FNA primarily performed in the IO, histopathological verification was achievable in 92 cases, from which 92 (100% provided a confirmation of cancer, and the remaining 18 patients were operated on outside the institute. High (100% specificity of cancer diagnosis in FNA established primarily and verified on CE (second independent assessment indicates that repeat FNA in order to confirm the diagnosis is unnecessary.

Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: a moderating role for cumulative risk.

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MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

2014-12-01

This study used the Fragile Families and Child Well-Being Study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2,768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. Copyright © 2014. Published by Elsevier Ltd.

Radiologic Analysis and Clinical Study of the Upper One-third Joint Technique for Fluoroscopically Guided Sacroiliac Joint Injection.

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Park, Junghyun; Park, Hue Jung; Moon, Dong Eon; Sa, Gye Jeol; Kim, Young Hoon

2015-01-01

Sacroiliac intraarticular injection by the traditional technique can be challenging to perform when the joint is covered with osteophytes or is extremely narrow. To examine whether there is enough space for the needle to be advanced from the L5-S1 interspinous space to the upper one-third sacroiliac joint (SIJ) by magnetic resonance image (MRI) analysis as an alternative to fluoroscopically guided SIJ injection with the lower one-third joint technique, and to determine the feasibility of this novel technique in clinical practice. MRI analysis and observational study. An interventional pain management practice at a university hospital. We analyzed 200 axial T2-weighted MRIs between the L5 and S1 vertebrae of 100 consecutive patients. The following measurements were obtained on both sides: 1) the thickness of fat in the midline; 2) the distance between the midline (Point C) and the junction (Point A) of the skin and the imaginary line that connects the SIJ and the most medial cortex of the ilium; 3) the distance between the midline (Point C) and the junction (Point B) of the skin and the imaginary line that connects the SIJ and the L5 spinous process; 4) the distance between the SIJ and midline (Point C) on the skin, or between the SIJ and the midpoint (Point C') of the line from Point A to Point B; and 5) the angle between the sagittal line and the imaginary line that connects the SIJ and the midline on the skin. The upper one-third joint technique was performed to establish the feasibility of the alternative technique in 20 patients who had unsuccessful sacroiliac intraarticular injections using the lower one-third joint technique. The mean distances from the midline to Point A and to Point B were 21.9 ± 13.7 mm and 27.8 ± 13.6 mm, respectively. The mean distance between the SIJ and Point C (or Point C') was 81.0 ± 13.3 mm. The angle between the sagittal line and the imaginary line that connects the SIJ and the midline on the skin was 42.8 ± 5.1°. The success

Electromyographic analysis of repeated bouts of eccentric exercise.

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McHugh, M P; Connolly, D A; Eston, R G; Gartman, E J; Gleim, G W

2001-03-01

The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.

40 CFR 1065.305 - Verifications for accuracy, repeatability, and noise.

Science.gov (United States)

2010-07-01

..., repeatability, and noise. 1065.305 Section 1065.305 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Verifications for accuracy, repeatability, and noise. (a) This section describes how to determine the accuracy, repeatability, and noise of an instrument. Table 1 of § 1065.205 specifies recommended values for individual...

Effects of repeated collaborative retrieval on individual memory vary as a function of recall versus recognition tasks.

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Blumen, Helena M; Rajaram, Suparna

2009-11-01

Our research examines how prior group collaboration modulates later individual memory. We recently showed that repeated collaborative recall sessions benefit later individual recall more than a single collaborative recall session (Blumen & Rajaram, 2008). Current research compared the effects of repeated collaborative recall and repeated collaborative recognition on later individual recall and later individual recognition. A total of 192 participants studied a list of nouns and then completed three successive retrieval sessions in one of four conditions. While two collaborative recall sessions and two collaborative recognition sessions generated comparable levels of individual recall (CRecall-CRecall-I Recall approximately CRecognition-CRecognition-I Recall , Experiment 1a), two collaborative recognition sessions generated greater levels of individual recognition than two collaborative recall sessions (CRecognition-CRecognition- IRecognition > CRecall-CRecall- I Recognition , Experiment 1b). These findings are discussed in terms of two opposing mechanisms that operate during collaborative retrieval-re-exposure and retrieval disruption-and in terms of transfer-appropriate processing across collaborative and individual retrieval sessions.

Fluoroscopically Guided Sacroiliac Joint Injections: Comparison of the Effects of Intraarticular and Periarticular Injections on Immediate and Short-Term Pain Relief.

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Nacey, Nicholas C; Patrie, James T; Fox, Michael G

2016-11-01

The purpose of this study was to determine whether intraarticular sacroiliac joint injections provide greater immediate and short-term pain relief than periarticular sacroiliac joint injections do. The records of all fluoroscopically guided sacroiliac joint injections performed over a 4-year period were identified. Patients who received an injection of 0.5 mL of bupivacaine and 0.5 mL (20 mg) of triamcinolone and who had preinjection, immediate, and 1-week postinjection pain scores (0-10 numeric scale) were included. Images from the procedures were retrospectively reviewed by two musculoskeletal radiologists to determine intraarticular or periarticular administration of the injection with discrepancies resolved by consensus. One hundred thirteen injections in 99 patients (65 women, 34 men; mean age, 59.4 years) met the inclusion criteria. There were 55 intraarticular and 58 periarticular injections. The mean preinjection, immediate, and 1-week postinjection pain scores for the intraarticular injections were 6.0, 1.6, and 4.1 and for the periarticular injections were 6.1, 2.0, and 4.2. The mean immediate and 1-week postinjection pain reduction were statistically significant in both groups (p sacroiliac joint injections provide statistically significant immediate and 1-week postinjection pain relief, no significant difference in the degree of pain relief achieved with intraarticular and periarticular injections was noted.

Accuracy of CT chest without oral contrast for ruling out esophageal perforation using fluoroscopic esophagography as reference standard: a retrospective study.

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Awais, Muhammad; Qamar, Saqib; Rehman, Abdul; Baloch, Noor Ul-Ain; Shafqat, Gulnaz

2018-02-26

Esophageal perforation has a high mortality rate. Fluoroscopic esophagography (FE) is the procedure of choice for diagnosing esophageal perforation. However, FE can be difficult to perform in seriously ill patients. We retrospectively reviewed charts and scans of all patients who had undergone thoracic CT (TCT) without oral contrast and FE for suspicion of esophageal perforation at our hospital between October, 2010 and December, 2015. Scans were interpreted by a single consultant radiologist having > 5 years of relevant experience. Statistical analysis was performed using SPSS version 20. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of TCT were computed using FE as reference standard. Of 122 subjects, 106 (83%) were male and their median age was 42 [inter-quartile range (IQR) 29-53] years. Esophageal perforation was evident on FE in 15 (8%) cases. Sensitivity, specificity, PPV and NPV of TCT for detecting esophageal perforation were 100, 54.6, 23.4 and 100%, respectively. When TCT was negative (n = 107), an alternative diagnosis was evident in 65 cases. Thoracic computed tomography (TCT) had 100% sensitivity and negative predictive value for excluding esophageal perforation. FE may be omitted in patients who have no evidence of mediastinal collection, pneumomediastinum or esophageal wall defect on TCT. However, in the presence of any of these features, FE is still necessary to confirm or exclude the presence of an esophageal perforation.

Rationale and design of the NO-PARTY trial: near-zero fluoroscopic exposure during catheter ablation of supraventricular arrhythmias in young patients.

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Casella, Michela; Dello Russo, Antonio; Pelargonio, Gemma; Bongiorni, Maria Grazia; Del Greco, Maurizio; Piacenti, Marcello; Andreassi, Maria Grazia; Santangeli, Pasquale; Bartoletti, Stefano; Moltrasio, Massimo; Fassini, Gaetano; Marini, Massimiliano; Di Cori, Andrea; Di Biase, Luigi; Fiorentini, Cesare; Zecchi, Paolo; Natale, Andrea; Picano, Eugenio; Tondo, Claudio

2012-10-01

Radiofrequency catheter ablation is the mainstay of therapy for supraventricular tachyarrhythmias. Conventional radiofrequency catheter ablation requires the use of fluoroscopy, thus exposing patients to ionising radiation. The feasibility and safety of non-fluoroscopic radiofrequency catheter ablation has been recently reported in a wide range of supraventricular tachyarrhythmias using the EnSite NavX™ mapping system. The NO-PARTY is a multi-centre, randomised controlled trial designed to test the hypothesis that catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system results in a clinically significant reduction in exposure to ionising radiation compared with conventional catheter ablation. The study will randomise 210 patients undergoing catheter ablation of supraventricular tachyarrhythmias to either a conventional ablation technique or one guided by the EnSite NavX™ mapping system. The primary end-point is the reduction of the radiation dose to the patient. Secondary end-points include procedural success, reduction of the radiation dose to the operator, and a cost-effectiveness analysis. In a subgroup of patients, we will also evaluate the radiobiological effectiveness of dose reduction by assessing acute chromosomal DNA damage in peripheral blood lymphocytes. NO-PARTY will determine whether radiofrequency catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system is a suitable and cost-effective approach to achieve a clinically significant reduction in ionising radiation exposure for both patient and operator.

Two tandemly repeated telomere-associated sequences in Nicotiana plumbaginifolia.

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Chen, C M; Wang, C T; Wang, C J; Ho, C H; Kao, Y Y; Chen, C C

1997-12-01

Two tandemly repeated telomere-associated sequences, NP3R and NP4R, have been isolated from Nicotiana plumbaginifolia. The length of a repeating unit for NP3R and NP4R is 165 and 180 nucleotides respectively. The abundance of NP3R, NP4R and telomeric repeats is, respectively, 8.4 x 10(4), 6 x 10(3) and 1.5 x 10(6) copies per haploid genome of N. plumbaginifolia. Fluorescence in situ hybridization revealed that NP3R is located at the ends and/or in interstitial regions of all 10 chromosomes and NP4R on the terminal regions of three chromosomes in the haploid genome of N. plumbaginifolia. Sequence homology search revealed that not only are NP3R and NP4R homologous to HRS60 and GRS, respectively, two tandem repeats isolated from N. tabacum, but that NP3R and NP4R are also related to each other, suggesting that they originated from a common ancestral sequence. The role of these repeated sequences in chromosome healing is discussed based on the observation that two to three copies of a telomere-similar sequence were present in each repeating unit of NP3R and NP4R.

The flow Rate Accuracy of Elastomeric Infusion Pumps After Repeated Filling.

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Mohseni, Masood; Ebneshahidi, Amin

2014-05-01

One of the frequent applications of elastomeric infusion pumps is postoperative pain management. In daily practice, the disposable pumps get refilled with modified medication combinations in the successive days; although, the accuracy of infusion rates is unknown to clinicians. Our aim was to evaluate the effect of repeated filling on the delivery rate accuracy of an elastomeric pump available in our market. We examined 10 elastomeric infusion pumps (BOT-802, Nanchang Biotek Medical Device Company, China) with 100 mL capacity and nominal flow of 5 mL/h. Each pump was filled for three times, accounting for 30 series of experiments. A microset scaled in mL was used to measure the pump deliveries. Flow profile and reliability of infusion rate were analyzed after repeated use. The mean flow rate in the three series of measurements showed a gradual increase; however, the difference was not statistically significant (5.01 ± 0.07 vs. 5.03 ± 0.06 vs. 5.06 ± 0.08 mL/h; P = 0.81). The percentage of the flow rate error (deviation from 5 mL/h ± 15%) was 100% in the first and second hours of infusion, 96% in the third hour, 60% in the 20th hour and zero percent in the rest of the infusion time. This study indicated that the delivery rate accuracy of elastomeric infusion pumps is preserved after repeated usage. These laboratory findings suggested that elastomeric pumps could be safely refilled in the successive days to provide postoperative analgesia.

A re-examination of the mere exposure effect: The influence of repeated exposure on recognition, familiarity, and liking.

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Montoya, R Matthew; Horton, Robert S; Vevea, Jack L; Citkowicz, Martyna; Lauber, Elissa A

2017-05-01

To evaluate the veracity of models of the mere exposure effect and to understand the processes that moderate the effect, we conducted a meta-analysis of the influence of repeated exposure on liking, familiarity, recognition, among other evaluations. We estimated parameters from 268 curve estimates drawn from 81 articles and revealed that the mere exposure effect was characterized by a positive slope and negative quadratic effect consistent with an inverted-U shaped curve. In fact, such curves were associated with (a) all visual, but not auditory stimuli; (b) exposure durations shorter than 10 s and longer than 1 min; (c) both homogeneous and heterogeneous presentation types; and (d) ratings that were taken after all stimuli were presented. We conclude that existing models for the mere exposure effect do not adequately account for the findings, and we provide a framework to help guide future research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Bullying and Repeated Conventional Transgressions in Swedish Schools: How Do Gender and Bullying Roles Affect Students' Conceptions?

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Thornberg, Robert; Pozzoli, Tiziana; Gini, Gianluca; Hong, Jun Sung

2017-01-01

Bullying is a moral transgression. Recognizing the importance of approaching bullying from a moral perspective, the present study examines whether children's judgments and reasoning to justify their judgments differ between bullying and repeated conventional transgressions. Our study also explores differences by gender and differences among…

47 CFR 80.469 - Maritime mobile repeater stations in Alaska.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime mobile repeater stations in Alaska. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Public Coast Stations Use of Telephony § 80.469 Maritime mobile repeater stations in Alaska. (a) Maritime mobile repeater stations are authorized to extend...

Clinical validation of an epigenetic assay to predict negative histopathological results in repeat prostate biopsies.

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Partin, Alan W; Van Neste, Leander; Klein, Eric A; Marks, Leonard S; Gee, Jason R; Troyer, Dean A; Rieger-Christ, Kimberly; Jones, J Stephen; Magi-Galluzzi, Cristina; Mangold, Leslie A; Trock, Bruce J; Lance, Raymond S; Bigley, Joseph W; Van Criekinge, Wim; Epstein, Jonathan I

2014-10-01

The DOCUMENT multicenter trial in the United States validated the performance of an epigenetic test as an independent predictor of prostate cancer risk to guide decision making for repeat biopsy. Confirming an increased negative predictive value could help avoid unnecessary repeat biopsies. We evaluated the archived, cancer negative prostate biopsy core tissue samples of 350 subjects from a total of 5 urological centers in the United States. All subjects underwent repeat biopsy within 24 months with a negative (controls) or positive (cases) histopathological result. Centralized blinded pathology evaluation of the 2 biopsy series was performed in all available subjects from each site. Biopsies were epigenetically profiled for GSTP1, APC and RASSF1 relative to the ACTB reference gene using quantitative methylation specific polymerase chain reaction. Predetermined analytical marker cutoffs were used to determine assay performance. Multivariate logistic regression was used to evaluate all risk factors. The epigenetic assay resulted in a negative predictive value of 88% (95% CI 85-91). In multivariate models correcting for age, prostate specific antigen, digital rectal examination, first biopsy histopathological characteristics and race the test proved to be the most significant independent predictor of patient outcome (OR 2.69, 95% CI 1.60-4.51). The DOCUMENT study validated that the epigenetic assay was a significant, independent predictor of prostate cancer detection in a repeat biopsy collected an average of 13 months after an initial negative result. Due to its 88% negative predictive value adding this epigenetic assay to other known risk factors may help decrease unnecessary repeat prostate biopsies. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Examining Postsecondary Education Predictors and Participation for Students with Learning Disabilities

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Joshi, Gauri S.; Bouck, Emily C.

2017-01-01

Given the history of poor postschool outcomes for students with disabilities, researchers repeatedly sought to demonstrate the links between predictor variables and postschool outcomes for students with disabilities. This secondary data analysis used the National Longitudinal Transition Study-2 to examine the relationship between postsecondary…

The scheduling of repeat cesarean section operations: prospective management protocol experience.

Science.gov (United States)

Read, J A

1985-03-01

There are benefits to patients and a busy obstetric service if repeat cesarean section operations are performed on a scheduled basis. Optimum management avoids prematurity and reduces the need for amniocentesis. Over a period of 20 months repeat cesarean sections were performed at Tripler Army Medical Center while a protocol with the following elements was used: (1) known last menstrual period; (2) landmarks: positive urine human chorionic gonadotropin test by 6 weeks, Doppler fetal heart tone by 12 weeks, date determination by examination before 10 weeks, fetoscope fetal heart tone by 20 weeks, and date determination by size before 30 weeks; (3) date determination by midtrimester sonogram(s); (4) normal third-trimester glucose screening; (5) biparietal diameter of 9.2 or 9.5 cm before scheduling. With two or more clinical landmarks and one date by sonogram or one landmark and date by two sonograms, elective repeat cesarean section was scheduled at 39 weeks if the biparietal diameter was greater than or equal to 9.2 cm (127). If dates by sonogram were less than dates by last menstrual period but greater than 1 week or if last menstrual period was unknown, dates by sonogram and landmarks corresponding to dates by sonogram were used to electively schedule, with biparietal diameters of 9.2 or 9.5 cm respectively required (28). If protocol criteria were not met or earlier delivery was indicated (e.g., vertical scar or diabetes), amniocentesis was performed (42), except when not possible, advisable, or refused when patients either elected labor (20) or were scheduled if three or more criteria for 40+ weeks were met (18). Of 225 patients (70.5%) scheduled by protocol (173), amniocentesis (34), or medical indication (18), 188 (58.9%) were delivered without labor. In the 147 patients (46.1%) delivered electively by protocol without labor or amniocentesis, there were no cases of respiratory distress syndrome and the mean birth weight was 3517 gm. With early care and better

StaRProtein, A Web Server for Prediction of the Stability of Repeat Proteins

Science.gov (United States)

Xu, Yongtao; Zhou, Xu; Huang, Meilan

2015-01-01

Repeat proteins have become increasingly important due to their capability to bind to almost any proteins and the potential as alternative therapy to monoclonal antibodies. In the past decade repeat proteins have been designed to mediate specific protein-protein interactions. The tetratricopeptide and ankyrin repeat proteins are two classes of helical repeat proteins that form different binding pockets to accommodate various partners. It is important to understand the factors that define folding and stability of repeat proteins in order to prioritize the most stable designed repeat proteins to further explore their potential binding affinities. Here we developed distance-dependant statistical potentials using two classes of alpha-helical repeat proteins, tetratricopeptide and ankyrin repeat proteins respectively, and evaluated their efficiency in predicting the stability of repeat proteins. We demonstrated that the repeat-specific statistical potentials based on these two classes of repeat proteins showed paramount accuracy compared with non-specific statistical potentials in: 1) discriminate correct vs. incorrect models 2) rank the stability of designed repeat proteins. In particular, the statistical scores correlate closely with the equilibrium unfolding free energies of repeat proteins and therefore would serve as a novel tool in quickly prioritizing the designed repeat proteins with high stability. StaRProtein web server was developed for predicting the stability of repeat proteins. PMID:25807112

Fluoroscopically guided transforaminal epidural steroid injections at a quaternary-care teaching institution: effect of trainee involvement and patient body mass index on fluoroscopy time and patient dose

International Nuclear Information System (INIS)

Tiegs-Heiden, C.A.; Murthy, N.S.; Geske, J.R.; Diehn, F.E.; Schueler, B.A.; Wald, J.T.; Kaufmann, T.J.; Lehman, V.T.; Carr, C.M.; Amrami, K.K.; Morris, J.M.; Thielen, K.R.; Maus, T.P.

2016-01-01

Aim: To investigate whether there are differences in fluoroscopy time and patient dose for fluoroscopically guided lumbar transforaminal epidural steroid injections (TFESIs) performed by staff radiologists versus with trainees and to evaluate the effect of patient body mass index (BMI) on fluoroscopy time and patient dose, including their interactions with other variables. Materials and methods: Single-level lumbar TFESIs (n=1844) between 1 January 2011 and 31 December 2013 were reviewed. Fluoroscopy time, reference point air kerma (K_a_,_r), and kerma area product (KAP) were recorded. BMI and trainee involvement were examined as predictors of fluoroscopy time, K_a_,_r, and KAP in models adjusted for age and gender in multivariable linear models. Stratified models of BMI groups by trainee presence were performed. Results: Increased age was the only significant predictor of increased fluoroscopy time (p<0.0001). K_a_,_r and KAP were significantly higher in patients with a higher BMI (p<0.0001 and p=0.0009). When stratified by BMI, longer fluoroscopy time predicted increased K_a_,_r and KAP in all groups (p<0.0001). Trainee involvement was not a statistically significant predictor of fluoroscopy time or K_a_,_r in any BMI category. KAP was lower with trainees in the overweight group (p=0.0009) and higher in male patients for all BMI categories (p<0.02). Conclusion: Trainee involvement did not result in increased fluoroscopy time or patient dose. BMI did not affect fluoroscopy time; however, overweight and obese patients received significantly higher K_a_,_r and KAP. Male patients received a higher KAP in all BMI categories. Limiting fluoroscopy time and good collimation practices should be reinforced in these patients. - Highlights: • Trainee involvement did not contribute to increased fluoroscopy time or dose. • BMI did not affect fluoroscopy time. • Overweight and obese patients received significantly higher Ka,r and KAP.

Differential Regulation of Strand-Specific Transcripts from Arabidopsis Centromeric Satellite Repeats.

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2005-12-01

Full Text Available Centromeres interact with the spindle apparatus to enable chromosome disjunction and typically contain thousands of tandemly arranged satellite repeats interspersed with retrotransposons. While their role has been obscure, centromeric repeats are epigenetically modified and centromere specification has a strong epigenetic component. In the yeast Schizosaccharomyces pombe, long heterochromatic repeats are transcribed and contribute to centromere function via RNA interference (RNAi. In the higher plant Arabidopsis thaliana, as in mammalian cells, centromeric satellite repeats are short (180 base pairs, are found in thousands of tandem copies, and are methylated. We have found transcripts from both strands of canonical, bulk Arabidopsis repeats. At least one subfamily of 180-base pair repeats is transcribed from only one strand and regulated by RNAi and histone modification. A second subfamily of repeats is also silenced, but silencing is lost on both strands in mutants in the CpG DNA methyltransferase MET1, the histone deacetylase HDA6/SIL1, or the chromatin remodeling ATPase DDM1. This regulation is due to transcription from Athila2 retrotransposons, which integrate in both orientations relative to the repeats, and differs between strains of Arabidopsis. Silencing lost in met1 or hda6 is reestablished in backcrosses to wild-type, but silencing lost in RNAi mutants and ddm1 is not. Twenty-four-nucleotide small interfering RNAs from centromeric repeats are retained in met1 and hda6, but not in ddm1, and may have a role in this epigenetic inheritance. Histone H3 lysine-9 dimethylation is associated with both classes of repeats. We propose roles for transcribed repeats in the epigenetic inheritance and evolution of centromeres.

Endovascular US: Adjunct to percutaneous atherectomy

International Nuclear Information System (INIS)

Schwarten, D.E.; Cutcliff, W.B.

1987-01-01

Percutaneous atherectomy with the Simpson atherectomy catheter has been performed at our institution since the third quarter of 1986. The first 45 patients underwent atherectomy with fluoroscopic guidance and multiplane documentary arteriography to assess the anatomic appearance of vessels after atherectomy and to assist in judging the completeness of the procedure. Each of the 45 patients underwent repeated cuts on each lesion until no further atheromatous specimens could be removed. Since late 1987, all lesions subjected to atherectomy have also been examined intraprocedure with an intraarterial US probe 0.040 inches in diameter fixed to a 0.040-inch guide wire and covered by a sonolucent radome. The US images were reviewed in real time and permitted much more accurate placement of the atherectomy catheter to effect more complete removal of the atheromatous material. It is anticipated that the use of the endovascular US device to accurately localize residual atheroma will result in more complete removal of atheroma, in turn decreasing the possibility of recurrence

Reproducibility of skeletal muscle vasodilatation responses to Stroop mental challenge over repeated sessions.

Science.gov (United States)

Hamer, Mark; Boutcher, Yati N; Park, Young; Boutcher, Stephen H

2006-08-01

Skeletal muscle blood flow responses to stress have implications for psychobiological disease pathways. An important assumption underlying psychophysiological studies relating stress reactivity with disease risk is that individuals are characterized by stable response profiles that can be reliably assessed using acute psychophysiological stress testing. We examined the reproducibility of forearm vasodilatation, blood pressure, and cardiac responses to a 2 min Stroop mental challenge over two repeated stress sessions that were on average 3.6 months apart. Participants were 21 healthy men and women (aged 21.8+/-3.7 years). Vasodilatation, blood pressure and heart rate responses displayed no habituation between sessions, although there was significantly greater cardiac parasympathetic involvement during the second testing session. Significant test-retest correlations between the sessions were observed for both forearm blood flow and heart rate reactivity. These findings demonstrate skeletal muscle vasodilatation responses to repeated stress are robust, so may be a useful psychophysiological indicator in studies of stress reactivity and disease risk.

Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress.

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Olivier Girard

Full Text Available Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C and CON (25°C conditions.Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting.Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001 and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05 temperatures, together with thermal comfort (P<0.001 were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001 and contact time (+3.2±2.4%; P<0.01 higher in HOT for the mean of sets 1-3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001, with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06. Mean vertical (-2.6±5.5%; P<0.01, horizontal (-9.1±4.4%; P<0.001 and resultant ground reaction forces (-3.0±2.8%; P<0.01 along with vertical stiffness (-12.9±2.3%; P<0.001 and leg stiffness (-8.4±2.7%; P<0.01 decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001, with lower propulsive power values in set 2 (-6.6%; P<0.05 in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise.Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations.

Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

Science.gov (United States)

Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

2017-01-01

Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

Telomerase Repeated Amplification Protocol (TRAP).

Science.gov (United States)

Mender, Ilgen; Shay, Jerry W

2015-11-20

Telomeres are found at the end of eukaryotic linear chromosomes, and proteins that bind to telomeres protect DNA from being recognized as double-strand breaks thus preventing end-to-end fusions (Griffith et al. , 1999). However, due to the end replication problem and other factors such as oxidative damage, the limited life span of cultured cells (Hayflick limit) results in progressive shortening of these protective structures (Hayflick and Moorhead, 1961; Olovnikov, 1973). The ribonucleoprotein enzyme complex telomerase-consisting of a protein catalytic component hTERT and a functional RNA component hTR or hTERC - counteracts telomere shortening by adding telomeric repeats to the end of chromosomes in ~90% of primary human tumors and in some transiently proliferating stem-like cells (Shay and Wright, 1996; Shay and Wright, 2001). This results in continuous proliferation of cells which is a hallmark of cancer. Therefore, telomere biology has a central role in aging, cancer progression/metastasis as well as targeted cancer therapies. There are commonly used methods in telomere biology such as Telomere Restriction Fragment (TRF) (Mender and Shay, 2015b), Telomere Repeat Amplification Protocol (TRAP) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this detailed protocol we describe Telomere Repeat Amplification Protocol (TRAP). The TRAP assay is a popular method to determine telomerase activity in mammalian cells and tissue samples (Kim et al. , 1994). The TRAP assay includes three steps: extension, amplification, and detection of telomerase products. In the extension step, telomeric repeats are added to the telomerase substrate (which is actually a non telomeric oligonucleotide, TS) by telomerase. In the amplification step, the extension products are amplified by the polymerase chain reaction (PCR) using specific primers (TS upstream primer and ACX downstream primer) and in the detection step, the presence or absence of telomerase is

Structure of thrombospondin type 3 repeats in bacterial outer membrane protein A reveals its intra-repeat disulfide bond-dependent calcium-binding capability

Energy Technology Data Exchange (ETDEWEB)

Dai, Shuyan; Sun, Cancan; Tan, Kemin; Ye, Sheng; Zhang, Rongguang

2017-09-01

Eukaryotic thrombospondin type 3 repeat (TT3R) is an efficient calcium ion (Ca2+) binding motif only found in mammalian thrombospondin family. TT3R has also been found in prokaryotic cellulase Cel5G, which was thought to forfeit the Ca2+-binding capability due to the formation of intra-repeat disulfide bonds, instead of the inter-repeat ones possessed by eukaryotic TT3Rs. In this study, we have identified an enormous number of prokaryotic TT3R-containing proteins belonging to several different protein families, including outer membrane protein A (OmpA), an important structural protein connecting the outer membrane and the periplasmic peptidoglycan layer in gram-negative bacteria. Here, we report the crystal structure of the periplasmic region of OmpA from Capnocytophaga gingivalis, which contains a linker region comprising five consecutive TT3Rs. The structure of OmpA-TT3R exhibits a well-ordered architecture organized around two tightly-coordinated Ca2+ and confirms the presence of abnormal intra-repeat disulfide bonds. Further mutagenesis studies showed that the Ca2+-binding capability of OmpA-TT3R is indeed dependent on the proper formation of intra-repeat disulfide bonds, which help to fix a conserved glycine residue at its proper position for Ca2+ coordination. Additionally, despite lacking inter repeat disulfide bonds, the interfaces between adjacent OmpA-TT3Rs are enhanced by both hydrophobic and conserved aromatic-proline interactions.

Discrepancy variation of dinucleotide microsatellite repeats in eukaryotic genomes

Directory of Open Access Journals (Sweden)

HUAN GAO

2009-01-01

Full Text Available To address whether there are differences of variation among repeat motif types and among taxonomic groups, we present here an analysis of variation and correlation of dinucleotide microsatellite repeats in eukaryotic genomes. Ten taxonomic groups were compared, those being primates, mammalia (excluding primates and rodentia, rodentia, birds, fish, amphibians and reptiles, insects, molluscs, plants and fungi, respectively. The data used in the analysis is from the literature published in the Journal of Molecular Ecology Notes. Analysis of variation reveals that there are no significant differences between AC and AG repeat motif types. Moreover, the number of alleles correlates positively with the copy number in both AG and AC repeats. Similar conclusions can be obtained from each taxonomic group. These results strongly suggest that the increase of SSR variation is almost linear with the increase of the copy number of each repeat motif. As well, the results suggest that the variability of SSR in the genomes of low-ranking species seem to be more than that of high-ranking species, excluding primates and fungi.

REPEATABILITY OF FRUIT QUALITY TRAITS OF CACTUS PEAR

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VALTÂNIA XAVIER NUNES

2017-12-01

Full Text Available ABSTRACT Repeatability analysis has been used to study traits in several crops, assisting in the definition of the minimum number needed to evaluate genotypes more efficiently and with less time and resource consumption. So far, however, no repeatability studies on cactus pear have been found in the literature. The objective of this study was to determine the coefficient of repeatability for cactus pear fruits traits and the minimum number of evaluations (fruit that can provide acceptable accuracy for the prediction of the true value. The experiment was conducted at the Federal Institute of Bahia/Campus Guanambi, with 150 fruits collected from three municipalities in the state of Bahia. The coefficients of repeatability were estimated by the methods of analysis of variance, principal components based on the covariance (PCCV and correlation (PCC matrices, and structural analysis based on the correlation matrix (SA. The analysis of variance showed that, except for fruit diameter, the effect of the production site (municipality was significant for all traits evaluated. The PCCV method was proven the most suitable for studying the repeatability of quality traits of cactus pear fruits. Seven fruits were required to determine, with 90% confidence, the traits length, diameter, fruit firmness, skin thickness, number of seeds, fruit mass, bark mass, pulp mass, pH, titratable acidity, soluble solids, SS/AT ratio, and pulp yield.

Baseline and annual repeat rounds of screening. Implications for optimal regimens of screening

Energy Technology Data Exchange (ETDEWEB)

Henschke, Claudia I.; Salvatore, Mary; Cham, Matthew; Eber, Corey; Yip, Rowena; Yankelevitz, David F. [Icahn School of Medicine at Mount Sinai, Department of Radiology, New York, NY (United States); Powell, Charles A.; DiFabrizio, Larry [Icahn School of Medicine at Mount Sinai, Department of Medicine, New York, NY (United States); Flores, Raja; Kaufman, Andrew [Icahn School of Medicine at Mount Sinai, Department of Thoracic Surgery, New York, NY (United States); Collaboration: International Early Lung Cancer Action Program Investigators

2018-03-15

Differences in results of baseline and subsequent annual repeat rounds provide important information for optimising the regimen of screening. A prospective cohort study of 65,374 was reviewed to examine the frequency/percentages of the largest noncalcified nodule (NCN), lung cancer cell types and Kaplan-Meier (K-M) survival rates, separately for baseline and annual rounds. Of 65,374 baseline screenings, NCNs were identified in 28,279 (43.3%); lung cancer in 737 (1.1%). Of 74,482 annual repeat screenings, new NCNs were identified in 4959 (7%); lung cancer in 179 (0.24%). Only adenocarcinoma was diagnosed in subsolid NCNs. Percentages of lung cancers by cell type were significantly different (p < 0.0001) in the baseline round compared with annual rounds, reflecting length bias, as were the ratios, reflecting lead times. Long-term K-M survival rate was 100% for typical carcinoids and for adenocarcinomas manifesting as subsolid NCNs; 85% (95% CI 81-89%) for adenocarcinoma, 74% (95% CI 63-85%) for squamous cell, 48% (95% CI 34-62%) for small cell. The rank ordering by lead time was the same as the rank ordering by survival rates. The significant differences in the frequency of NCNs and frequency and aggressiveness of diagnosed cancers in baseline and annual repeat need to be recognised for an optimal regimen of screening. (orig.)

The absolute number of repeat operations for complex intra ...

African Journals Online (AJOL)

abdominal sepsis, questions about futility of treatment frequently arise. This study focuses specifically on patients who required two or more repeat laparotomies and describes the spectrum of disease necessitating multiple repeat laparotomies ...

Assembly of Repeat Content Using Next Generation Sequencing Data

Energy Technology Data Exchange (ETDEWEB)

labutti, Kurt; Kuo, Alan; Grigoriev, Igor; Copeland, Alex

2014-03-17

Repetitive organisms pose a challenge for short read assembly, and typically only unique regions and repeat regions shorter than the read length, can be accurately assembled. Recently, we have been investigating the use of Pacific Biosciences reads for de novo fungal assembly. We will present an assessment of the quality and degree of repeat reconstruction possible in a fungal genome using long read technology. We will also compare differences in assembly of repeat content using short read and long read technology.

Molecular Characterization of Respiratory Syncytial Virus in Children with Repeated Infections with Subgroup B in the Philippines.

Science.gov (United States)

Okamoto, Michiko; Dapat, Clyde P; Sandagon, Ann Marie D; Batangan-Nacion, Leilanie P; Lirio, Irene C; Tamaki, Raita; Saito, Mayuko; Saito-Obata, Mariko; Lupisan, Socorro P; Oshitani, Hitoshi

2018-05-02

Human respiratory syncytial virus (RSV) is the leading cause of severe acute respiratory infection in infants and young children, which is characterized by repeated infections. However, the role of amino acid substitutions in repeated infections remains unclear. Hence, this study aimed to elucidate the genetic characteristics of RSV in children with repeated infections using molecular analyses of F and G genes. We conducted a cohort study for children younger than 5 years in the Philippines. We collected nasopharyngeal swabs from children with acute respiratory symptoms and compared F and G sequences between prior and subsequent RSV infections. We examined 1,802 children from May 2014 to January 2016 and collected 3,471 samples. Repeated infections were observed in 25 children, including 4 with homologous RSV-B reinfections. Viruses from the 4 pairs of homologous reinfections had amino acid substitutions in the G protein mostly at O-glycosylation sites, whereas changes in the F protein were identified at antigenic sites V (L173S) and θ (Q209K), considered essential epitopes for the prefusion conformation of the F protein. Amino acid substitutions in G and F proteins of RSV-B might have led to antigenic changes, potentially contributing to homologous reinfections observed in this study.

A study on the repeatability of ultrasonic testing data

International Nuclear Information System (INIS)

Yoshimura, Seiichi; Fukumoto, Hiroshi

1980-01-01

Reliability improvement of ultrasonic testing data is strongly desired in ultrasonic testing working of nuclear power plants. This paper deals with the problems of the testing by the manual and the remote control apparatus, and with the factors which influence the repeatability of ultrasonic testing data. Following results are found in it. (1) In the testing by the manual, working time and posture influence the repeatability of testing data. (2) Glycerin in suitable for the couplant in the respect of the repeatability of testing data. In the case of using machine oil, the pressure to the probe necessitates to be over 0.2 kg/cm 2 . (3) In the testing by the remote control apparatus, working time, working environment and defect position does not influence the repeatability of testing data. (author)

Proportional lumbar spine inter-vertebral motion patterns: a comparison of patients with chronic, non-specific low back pain and healthy controls.

Science.gov (United States)

Mellor, Fiona E; Thomas, Peter W; Thompson, Paul; Breen, Alan C

2014-10-01

Identifying biomechanical subgroups in chronic, non-specific low back pain (CNSLBP) populations from inter-vertebral displacements has proven elusive. Quantitative fluoroscopy (QF) has excellent repeatability and provides continuous standardised inter-vertebral kinematic data from fluoroscopic sequences allowing assessment of mid-range motion. The aim of this study was to determine whether proportional continuous IV rotational patterns were different in patients and controls. A secondary aim was to update the repeatability of QF measurement of range of motion (RoM) for inter-vertebral (IV) rotation. Fluoroscopic sequences were recorded of passive, recumbent coronal and sagittal motion, which was controlled for range and velocity. Segments L2-5 in 40 primary care CNSLBP patients and 40 matched controls were compared. Patients also completed the von Korff Chronic Pain Grade and Roland and Morris Disability Questionnaire. Sequences were processed using automated image tracking algorithms to extract continuous inter-vertebral rotation data. These were converted to continuous proportional ranges of rotation (PR). The continuous proportional range variances were calculated for each direction and combined to produce a single variable representing their fluctuation (CPRV). Inter- and intra-rater repeatability were also calculated for the maximum IV-RoM measurements obtained during controlled trunk motion to provide an updated indication of the reliability and agreement of QF for measuring spine kinematics. CPRV was significantly higher in patients (0.011 vs. 0.008, Mann-Whitney two-sided p = 0.008), implying a mechanical subgroup. Receiver operating characteristic curve analysis found its sensitivity and specificity to be 0.78 % (60-90) and 0.55 % (37-73), respectively (area under the curve 0.672). CPRV was not correlated with pain severity or disability. The repeatability of maximum inter-vertebral range was excellent, but range was only significantly greater in patients

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

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Bernardo T. Lopes

2017-01-01

Full Text Available Purpose. To assess the repeatability and reproducibility of dynamic corneal response parameters measured by the Corvis ST (Oculus, Wetzlar, Germany. Methods. One eye randomly selected from 32 healthy volunteers was examined by the Corvis ST. Three different devices were used in an alternated random order for taking three measurements at each device in each subject. Standard intraocular pressure (IOP, the biomechanical-compensated IOP (bIOP, and DCR parameters were evaluated. The within-subject standard deviation (ζw and coefficient of variation (CV were assessed. Results. Regarding pressure indices, the ζw was below 1 mmHg for repeatability (0.98 for IOP and 0.89 for bIOP and the CV was 6.6% for IOP and 6.1% for bIOP. For reproducibility, the ζw was around 1 mmHg (1.12 for IOP and 1.05 for bIOP and the CV was 7.6% for IOP and 7.1% for bIOP. Most of DCR indices presented CV for repeatability below 4%. For reproducibility, the CV of most of the indices were below 6%. The deformation amplitude (DA ratio in 1 mm and integrated radius were below 4% (1.2% and 3.8%, resp.. Conclusions. The Corvis ST showed good precision (repeatability and reproducibility for IOP measurements and for DCR in healthy eyes.

Examination of fatigue development in elite soccer in a hot environment: a multi-experimental approach

DEFF Research Database (Denmark)

Mohr, Magni; Mujika, I; Santisteban, J

2010-01-01

The study examines fatigue in elite soccer played in hot conditions. High-profile soccer players (n=20) were studied during match play at ~31 °C. Repeated sprint and jump performances were assessed in rested state and after a game and activity profile was examined. Additionally, heart rate (HR...

Test-retest repeatability of strength capacity, aerobic power and pericranial tenderness of neck and shoulder muscles in children - relevant for tension-type headache

DEFF Research Database (Denmark)

Tornøe, Birte; Andersen, Lars L; Skotte, J H

2013-01-01

Frequent or chronic tension-type headache in children is a prevalent and debilitating condition for the child, often leading to medication overuse. To explore the relationship between physical factors and tension-type headache in children, the quality of repeated measures was examined. The aim of...... of the present study was to determine the test-retest repeatability of parameters determining isometric neck and shoulder strength and stability, aerobic power, and pericranial tenderness in children....

Non-radioactive detection of trinucleotide repeat size variability.