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Flat panel detectors

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https://www.readbyqxmd.com/read/28649157/use-of-patient-specific-3d-printed-neurovascular-phantoms-to-evaluate-the-clinical-utility-of-a-high-resolution-x-ray-imager
#1
S V Setlur Nagesh, M Russ, C N Ionita, D Bednarek, S Rudin
Modern 3D printing technology can fabricate vascular phantoms based on an actual human patient with a high degree of precision facilitating a realistic simulation environment for an intervention. We present two experimental setups using 3D printed patient-specific neurovasculature to simulate different disease anatomies. To simulate the human neurovasculature in the Circle of Willis, patient-based phantoms with aneurysms were 3D printed using a Objet Eden 260V printer. Anthropomorphic head phantoms and a human skull combined with acrylic plates simulated human head bone anatomy and x-ray attenuation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28637959/examination-of-dose-reduction-using-image-noise-reduction-technology-in-cardiovascular-x-ray-systems
#2
Takaya Saijo, Shigenobu Seguchi
The aim of this study is to establish radiation exposure dose reduction protocols during cardiac intervention by decreasing the entrance dose at flat panel detector (FPD) with image quality evaluations. For measuring entrance surface dose (ESD), we have used a Radical 9015 dosimeter (6 cc ion chamber) placed under 20 cm thick acrylic plates at the patient's entrance reference point. We performed an image quality assessment based on quantitative as well as visual evaluation of the images obtained via current and dose reduction protocols...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28632551/comparative-study-of-c-arms-for-intraoperative-3-dimensional-imaging-and-navigation-in-minimally-invasive-spine-surgery-part-i-applicability-and-image-quality
#3
Jan-Helge Klingler, Ronen Sircar, Christian Scheiwe, Evangelos Kogias, Florian Volz, Marie T Krüger, Ulrich Hubbe
STUDY DESIGN: This was a retrospective analysis. OBJECTIVE: This study compares 2 different 3-dimensional (3D) C-arm devices for intraoperative imaging and navigation with regard to clinical applicability and image quality. SUMMARY OF BACKGROUND DATA: Minimally invasive spine surgery requires intraoperative imaging techniques to adequately visualize the unexposed spine. For this purpose, mobile 3D C-arms became available along with the evolution of intraoperative navigation techniques...
July 2017: Clinical Spine Surgery
https://www.readbyqxmd.com/read/28626289/comparison-of-high-resolution-x-ray-detectors-with-conventional-fpds-using-experimental-mtfs-and-apodized-aperture-pixel-design-for-reduced-aliasing
#4
A Shankar, M Russ, S Vijayan, D R Bednarek, S Rudin
Apodized Aperture Pixel (AAP) design, proposed by Ismailova et. al, is an alternative to the conventional pixel design(1). The advantages of AAP processing with a sinc filter in comparison with using other filters include non-degradation of MTF values and elimination of signal and noise aliasing, resulting in an increased performance at higher frequencies, approaching the Nyquist frequency(3). If high resolution small field-of-view (FOV) detectors with small pixels used during critical stages of Endovascular Image Guided Interventions (EIGIs) could also be extended to cover a full field-of-view typical of flat panel detectors (FPDs) and made to have larger effective pixels, then methods must be used to preserve the MTF over the frequency range up to the Nyquist frequency of the FPD while minimizing aliasing...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28625472/3d-catheter-reconstruction-in-hdr-prostate-brachytherapy-for-pre-treatment-verification-using-a-flat-panel-detector
#5
Ryan L Smith, Annette Haworth, Vanessa Panettieri, Jeremy L Millar, Rick D Franich
PURPOSE: High dose rate prostate brachytherapy is a widely-practiced treatment, delivering large conformal doses in relatively few treatment fractions. Inter- and intra-fraction catheter displacements have been reported. Unrecognized displacement can have a significant impact on dosimetry. Knowledge of the implant geometry at the time of treatment is important for ensuring safe and effective treatment. In this work we demonstrate a method to reconstruct the catheter positions pre-treatment, using a 'shift' imaging technique, and perform registration with the treatment plan for verification relative to the prostate...
June 15, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28624018/difference-in-the-craniocaudal-gradient-of-the-maximum-pixel-value-change-rate-between-chronic-obstructive-pulmonary-disease-patients-and-normal-subjects-using-sub-mgy-dynamic-chest-radiography-with-a-flat-panel-detector-system
#6
Yoshitake Yamada, Masako Ueyama, Takehiko Abe, Tetsuro Araki, Takayuki Abe, Mizuki Nishino, Masahiro Jinzaki, Hiroto Hatabu, Shoji Kudoh
OBJECTIVES: To compare the craniocaudal gradients of the maximum pixel value change rate (MPCR) during tidal breathing between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. MATERIALS AND METHODS: This prospective study was approved by the institutional review board and all participants provided written informed consent. Forty-three COPD patients (mean age, 71.6±8.7 years) and 47 normal subjects (non-smoker healthy volunteers) (mean age, 54...
July 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28609790/analysis-of-patients-x-ray-exposure-in-146-percutaneous-radiologic-gastrostomies
#7
Tim Ole Petersen, Martin Reinhardt, Jochen Fuchs, Dieter Gosch, Alexey Surov, Patrick Stumpp, Thomas Kahn, Michael Moche
Purpose Analysis of patient´s X-ray exposure during percutaneous radiologic gastrostomies (PRG) in a larger population. Materials and Methods Data of primary successful PRG-procedures, performed between 2004 and 2015 in 146 patients, were analyzed regarding the exposition to X-ray. Dose-area-product (DAP), dose-length-product (DLP) respectively, and fluoroscopy time (FT) were correlated with the used x-ray systems (Flatpanel Detector (FD) vs. Image Itensifier (BV)) and the necessity for periprocedural placement of a nasogastric tube...
June 13, 2017: RöFo: Fortschritte Auf Dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
https://www.readbyqxmd.com/read/28585520/iterative-image-domain-ring-artifact-removal-in-cone-beam-ct
#8
Xiaokun Liang, Zhicheng Zhang, Tianye Niu, Shaode Yu, Shibin Wu, Zhicheng Li, Huailing Zhang, Yaoqin Xie
Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is based on the polar coordinate system, where the ring artifacts manifest as stripe artifacts. Using relative total variation, the CBCT images are first smoothed to generate template images with fewer image details and ring artifacts...
July 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28543761/experimental-characterization-of-a-direct-conversion-amorphous-selenium-detector-with-thicker-conversion-layer-for-dual-energy-contrast-enhanced-breast-imaging
#9
David A Scadutom, Olivier Tousignant, Wei Zhao
PURPOSE: Dual-energy contrast-enhanced imaging is being investigated as a tool to identify and localize angiogenesis in the breast, a possible indicator of malignant tumors. This imaging technique requires that x-ray images are acquired at energies above the k-shell binding energy of an appropriate radiocontrast agent. Iodinated contrast agents are commonly used for vascular imaging, and require x-ray energies greater than 33 keV. Conventional direct conversion amorphous selenium (a-Se) flat panel imagers for digital mammography show suboptimal absorption efficiencies at these higher energies...
May 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28529251/image-quality-and-clinical-usefulness-of-ray-summation-image-reconstructed-from-ct-data-compared-with-digital-radiography
#10
Shogo Suzuki, Katsuhiro Ichikawa, Shigeru Tamaki
Ray-summation (raysum) images reconstructed from computed tomography (CT) volume data resemble digital radiography (DR) images. Therefore, they have a potential to be used instead of DR images.The aim of this study was to compare the physical image quality evaluated by signal-difference-to-noise ratio (SDNR) and clinical usefulness between raysum and DR images. We employed an oval water phantom simulating adult abdomen for image quality measurement. Raysum images were reconstructed from CT volume data using an assumed x-ray quality of 70 keV...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28516271/three-dimensional-image-fusion-guidance-for-transjugular-intrahepatic-portosystemic-shunt-placement
#11
Vania Tacher, Arthur Petit, Haytham Derbel, Luigi Novelli, Manuel Vitellius, Fourat Ridouani, Alain Luciani, Alain Rahmouni, Christophe Duvoux, Chady Salloum, Mélanie Chiaradia, Hicham Kobeiter
INTRODUCTION: To assess the safety, feasibility and effectiveness of image fusion guidance with pre-procedural portal phase computed tomography with intraprocedural fluoroscopy for transjugular intrahepatic portosystemic shunt (TIPS) placement. MATERIALS AND METHODS: All consecutive cirrhotic patients presenting at our interventional unit for TIPS creation from January 2015 to January 2016 were prospectively enrolled. Procedures were performed under general anesthesia in an interventional suite equipped with flat panel detector, cone-beam computed tomography (CBCT) and image fusion technique...
May 17, 2017: Cardiovascular and Interventional Radiology
https://www.readbyqxmd.com/read/28382313/geometric-calibration-and-correction-for-a-lens-coupled-detector-in-x-ray-phase-contrast-imaging
#12
Alex George, Peter Y Chen, Alejandro Morales-Martinez, Alireza Panna, Andrew A Gomella, Eric E Bennett, Han Wen
A lens-coupled x-ray camera with a tilted phosphor collects light emission from the x-ray illuminated (front) side of phosphor. Experimentally, it has been shown to double x-ray photon capture efficiency and triple the spatial resolution along the phosphor tilt direction relative to the same detector at normal phosphor incidence. These characteristics benefit grating-based phase-contrast methods, where linear interference fringes need to be clearly resolved. However, both the shallow incident angle on the phosphor and lens aberrations of the camera cause geometric distortions...
January 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/28355964/study-of-image-qualities-from-6d-robot-based-cbct-imaging-system-of-small-animal-irradiator
#13
Sunil Sharma, Ganesh Narayanasamy, Richard Clarkson, Ming Chao, Eduardo G Moros, Xin Zhang, Yulong Yan, Marjan Boerma, Nava Paudel, Steven Morrill, Peter Corry, Robert J Griffin
PURPOSE: To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. METHOD AND MATERIALS: The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6 degrees of freedom robot for cone beam computed tomography imaging and conformal delivery of radiation doses...
January 1, 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/28343304/geometry-calibration-between-x-ray-source-and-detector-for-tomosynthesis-with-a-portable-x-ray-system
#14
Kohei Sato, Takashi Ohnishi, Masashi Sekine, Hideaki Haneishi
PURPOSE: Tomosynthesis is attracting attention as a low-dose tomography technology compared with X-ray CT. However, conventional tomosynthesis imaging devices are large and stationary. Furthermore, there is a limitation in the working range of the X-ray source during image acquisition. We have previously proposed the use of a portable X-ray device for tomosynthesis that can be used for ward rounds and emergency medicine. The weight of this device can be reduced by using a flat panel detector (FPD), and flexibility is realized by the free placement of the X-ray source and FPD...
March 25, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28296304/low-dose-2-5-mv-cone-beam-computed-tomography-with-thick-csi-flat-panel-imager
#15
Grace Tang, Christopher Moussot, Daniel Morf, Edward Seppi, Howard Amols
Most of the treatment units, both new and old models, are equipped with a megavoltage portal imager but its use for volumetric imaging is limited. This is mainly due to the poor image quality produced by the high-energy treatment beam (>6 MV). A linac at our center is equipped with a prototype 2.5 MV imaging beam. This study evaluates the feasibility of low-dose megavoltage cone-beam imaging with the 2.5 MV beam and a thick cesium iodide detector, which is a high-efficiency imager. Basic imaging properties such as spatial resolution and modulation transfer function were assessed for the 2...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28289756/predictive-value-of-pooled-cerebral-blood-volume-mapping-for-final-infarct-volume-in-patients-with-major-artery-occlusions-a%C3%A2-retrospective-analysis
#16
Lauma Ava, Joachim Berkefeld, Arne Lauer, Alexander Seiler, Waltraud Pfeilschifter, Monika Müller-Eschner, Se-Jong You, Stefan Weidauer, Ulrich Pilatus, Marlies Wagner
PURPOSE: Detection of ischemic core and collateral status is helpful to predict clinical success of thrombectomy in acute cerebral artery occlusion. Angiographic flat panel detector computed tomography (CT) with pooled blood volume (PBV) data acquisition was described to be helpful to estimate ischemic core in stroke patients prior to thrombectomy and to depict cerebral vessels. We therefore retrospectively evaluated preinterventional PBV data of a large collective of ischemic stroke patients prior to thrombectomy to test its predictive value on final infarct considering PBV maps and collateral status...
March 13, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28216522/technical-problems-of-wireless-type-portable-flat-panel-detector
#17
Yutaka Nishibata
No abstract text is available yet for this article.
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28209577/feasibility-of-flat-panel-detector-ct-in-perfusion-assessment-of-brain-arteriovenous-malformations-initial-clinical-experience
#18
M Garcia, T W Okell, M Gloor, M A Chappell, P Jezzard, O Bieri, J V Byrne
The different results from flat panel detector CT in various pathologies have provoked some discussion. Our aim was to assess the role of flat panel detector CT in brain arteriovenous malformations, which has not yet been assessed. Five patients with brain arteriovenous malformations were studied with flat panel detector CT, DSC-MR imaging, and vessel-encoded pseudocontinuous arterial spin-labeling. In glomerular brain arteriovenous malformations, perfusion was highest next to the brain arteriovenous malformation with decreasing values with increasing distance from the lesion...
February 16, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28169225/intensity-based-2d-3d-registration-for-lead-localization-in-robot-guided-deep-brain-stimulation
#19
Stefan Hunsche, Dieter Sauner, Faycal El Majdoub, Clemens Neudorfer, Jörg Poggenborg, Axel Goßmann, Mohammad Maarouf
Intraoperative assessment of lead localization has become a standard procedure during deep brain stimulation surgery in many centers, allowing immediate verification of targeting accuracy and, if necessary, adjustment of the trajectory. The most suitable imaging modality to determine lead positioning, however, remains controversially discussed. Current approaches entail the implementation of computed tomography and magnetic resonance imaging. In the present study, we adopted the technique of intensity-based 2D 3D registration that is commonly employed in stereotactic radiotherapy and spinal surgery...
March 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28159651/a-multicenter-survey-of-endovascular-theatre-equipment-and-radiation-exposure-in-france-during-iliac-procedures
#20
Blandine Maurel, Adrien Hertault, Lucie Salomon du Mont, Sébastien Cazaban, Simon Rinckenbach
BACKGROUND: The aim of this study is to evaluate radiation exposure, endovascular theatre equipment, and practices in France during iliac angioplasty. METHODS: A prospective observational study was performed among vascular surgeons who attended a half day of radiation safety training in 2012 and 2015 and had to collect data on 3 patients undergoing iliac procedure. In 2012, 330 surgeons performed 899 procedures, compared with 114 surgeons and 338 procedures in 2015...
February 1, 2017: Annals of Vascular Surgery
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