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Flat panel detectors

N Van Peteghem, H Bosmans, N W Marshall
To propose and validate a non-prewhitening with eye filter (NPWE) model observer as an alternative means of quantifying and specifying imaging performance for general radiography detectors, in a comparative study with contrast detail analysis and detective quantum efficiency (DQE). Five different x-ray detectors were assessed, covering a range of detector technologies including powder computed radiography (CR), needle CR, and three indirect conversion flat panel digital radiography detectors (DR). For each detector, threshold contrast detail (c-d) detectability was measured using the Leeds TO20 test object...
November 7, 2016: Physics in Medicine and Biology
Antonio Sarno, Giovanni Mettivier, Francesca Di Lillo, Mario Cesarelli, Paolo Bifulco, Paolo Russo
We developed a scanner for micro computed tomography dedicated to the breast (BµCT) with a high resolution flat-panel detector and a microfocus X-ray tube. We evaluated the system spatial resolution via the 3D modulation transfer function (MTF). In addition to conventional absorption-based X-ray imaging, such a prototype showed capabilities for propagation-based phase-contrast and related edge enhancement effects in 3D imaging. The system limiting spatial resolution is 6.2mm(-1) (MTF at 10%) in the vertical direction and 3...
October 7, 2016: Medical Engineering & Physics
Navnina Bhatia, David Tisseur, Solene Valton, Jean Michel Létang
Due to the increased cone beam coverage and the introduction of flat panel detector, the size of X-ray illumination fields has grown dramatically in Cone Beam Computed Tomography (CBCT), causing an increase in scatter radiation. Existing reconstruction algorithms do not model the scatter radiation, so scatter artifacts appear in the reconstruction images. The contribution of scattering of photons inside the detector itself becomes prominent and challenging in case of X-ray source of high energy (over a few 100 keV) which is used in typical industrial Non Destructive Testing (NDT)...
October 6, 2016: Journal of X-ray Science and Technology
Muhammad U Ghani, Liqiang Ren, Molly Wong, Yuhua Li, Bin Zheng, Xiujiang John Rong, Kai Yang, Hong Liu
OBJECTIVE: The aim of this study was to investigate the noise power properties of a micro-computed tomography (micro-CT) system under different operating conditions. METHODS: A commercial micro-CT was used in the study that used a flat panel detector with a 127-μm-pixel pitch and a micro-focus x-ray tube. Conical tubes of various diameters were used under different acquisition conditions. Multidimensional noise power spectrums were used as a metric to investigate the noise properties of the system...
September 27, 2016: Journal of Computer Assisted Tomography
Tabassum A Kennedy, Nathan Connell, Timothy Szczykutowicz, Sebastian Schafer, Kevin Royalty, Sara Nace, Brian Gartrell, Samuel Gubbels
HYPOTHESIS: Flat-panel computed tomography (FPCT) will allow more accurate localization of cochlear implants with decreased metallic artifact and decreased radiation dose when compared with multi-detector CT (MDCT). BACKGROUND: The measurement of scalar location and intra-scalar position of cochlear implantation (CI) electrodes using computed tomography (CT) is complicated by metallic image artifact and insufficient scalar resolution. FPCT has been shown to improve upon the resolution of MDCT while reducing artifact...
September 23, 2016: Otology & Neurotology
Anastasia C Hadjiconstanti, Gerasimos A T Messaris, Konstantinos C Thomopoulos, Aikaterini G Solomou, George S Panayiotakis
A phantom-based study is presented aiming to optimise patient dose and image quality (IQ) in endoscopic retrograde cholangiopancreatography procedures, utilising a fluoroscopy system equipped with a flat panel detector. The patient thickness was simulated with various polymethyl methacrylate slabs, whilst IQ was evaluated using the Leeds test object. The main factors evaluated were phantom thickness, distance between phantom and detector, field of view and pulse rate. For all these factors, the dosemetric indices, entrance surface air kerma (ESAK) rate and ESAK per pulse, as well as the IQ parameters, signal-to-noise ratio and high contrast spatial resolution, were measured...
September 24, 2016: Radiation Protection Dosimetry
O Gonschorek, S Hauck, V Bühren
BACKGROUND: Intraoperative imaging during spinal interventions has experienced significant developments over the last two decades. By the introduction of flat screen detectors, 3D imaging has been made possible and easier and by developing compact and mobile systems computed tomography can even be used in the operating theater. OBJECTIVE: Presentation of modern intraoperative 3D imaging and navigation in spinal surgery. MATERIAL AND METHODS: The techniques of intraoperative 3D imaging and navigation during spinal procedures are presented based on the currently available literature and own experiences at a German national spine and trauma center...
October 2016: Der Unfallchirurg
Shiro Onozawa, Satoru Murata, Takayoshi Kimura, Tatsuo Ueda, Fumie Sugihara, Daisuke Yasui, Hiroyuki Tajima
PURPOSE: To investigate how elevation of the arms affects diaphragm height. MATERIALS AND METHODS: We retrospectively reviewed angiography and computed tomography (CT) portography data from 44 patients who were treated for hepatocellular carcinoma at our institution from July 2013 to May 2014. Diaphragm height was determined independently by two radiologists as the distance from the upper edge of the first lumbar vertebra to the highest point of the right diaphragm...
September 9, 2016: Japanese Journal of Radiology
Roberto Miraglia, Roberta Gerasia, Luigi Maruzzelli, Mario D'Amico, Angelo Luca
OBJECTIVES: The aim of this study was to prospectively evaluate effective dose (E) of operators performing transjugular intrahepatic portosystemic shunts (TIPS) in a single centre. Patients' radiation exposure was also collected. METHODS: Between 8/2015 and 6/2016, 45 consecutive TIPS were performed in adult patients using a flat-panel detector-based system (FPDS) and real-time ultrasound guidance (USG) for portal vein targeting. Electronic personal dosimeters were used to measure radiation doses to the primary and assistant operators, anaesthesia nurse and radiographer...
August 25, 2016: European Radiology
Moritz Wildgruber, René Müller-Wille, Holger Goessmann, Wibke Uller, Walter A Wohlgemuth
OBJECTIVE: The aim of the study was to calculate the effective dose during fluoroscopy-guided pediatric interventional procedures of the liver in a phantom model before and after adjustment of preset parameters. METHODS: Organ doses were measured in three anthropomorphic Rando-Alderson phantoms representing children at various age and body weight (newborn 3.5kg, toddler 10kg, child 19kg). Collimation was performed focusing on the upper abdomen representing mock interventional radiology procedures such as percutaneous transhepatic cholangiography and drainage placement (PTCD)...
2016: PloS One
Norisato Tsuda, Kota Mitsui, Shinichiro Oda
The purpose of this study was to investigate the effect of the position in XYZ directions and acquisition parameters on the basic image qualities of for cone beam computed tomography (CBCT) in an angiography system with flat panel detector. The resolution property (modulation transfer function: MTF) and the noise property (Wiener spectrum: WS) of CBCT images in X-Y plane were measured with different acquisition parameters (scan matrix number and projection number) and the effect of the position in XYZ directions...
August 2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
Naoya Kozono, Takamitsu Okada, Naohide Takeuchi, Satoshi Hamai, Hidehiko Higaki, Satoru Ikebe, Takeshi Shimoto, Go Miake, Yoshitaka Nakanishi, Yukihide Iwamoto
PURPOSE: The purpose of this study was to evaluate the kinematics of healthy shoulders during dynamic full axial rotation and scapular plane full abduction using three-dimensional (3D)-to-two-dimensional (2D) model-to-image registration techniques. METHODS: Dynamic glenohumeral kinematics during axial rotation and scapular plane abduction were analysed in 10 healthy participants. Continuous radiographic images of axial rotation and scapular plane abduction were taken using a flat panel radiographic detector...
August 10, 2016: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
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 (> 6MV). 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 2.5MV 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...
2016: Journal of Applied Clinical Medical Physics
Zhaohui Han, Davide Brivio, Erno Sajo, Piotr Zygmanski
A prototype topological detector was fabricated and investigated for quality assurance of radiation producing medical devices. Unlike a typical array or flat panel detector, a topological detector, while capable of achieving a very high spatial resolution, consists of only a few elements and therefore is much simpler in construction and more cost effective. The key feature allowing this advancement is a geometry-driven design that is customized for a specific dosimetric application. In the current work, a topological detector of two elements was examined for the positioning verification of the radiation collimating devices (jaws, MLCs, and blades etc)...
August 21, 2016: Physics in Medicine and Biology
Zhicheng Zhang, Shaode Yu, Xiaokun Liang, Yanchun Zhu, Yaoqin Xie
Artifacts induced by respiratory motion during routine diagnosis severely degrades the image quality. The increase of scanning speed plays an important role to avoid motion artifacts. Limited to the mechanical structure of conventional CT, the increase of gantry rotational speed is unsustainable and a more feasible way is to increase the number of X-ray sources and detectors like the dual-source CT. This paper focuses on high-speed scanning CT and proposes a novel ultrafast micro-CT (UMCT) system based on carbon nanotube (CNT)...
July 13, 2016: Physica Medica: PM
Jan-Helge Klingler, Ronen Sircar, Christian Scheiwe, Evangelos Kogias, Florian Volz, Marie T Krüger, Ulrich Hubbe
STUDY DESIGN: Retrospective analysis. OBJECTIVE: This study compares two different three-dimensional (3D) C-arm devices for intraoperative imaging and navigation in 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...
June 28, 2016: Clinical Spine Surgery
Sanaz Kaviani, Navid Zeraatkar, Salar Sajedi, Afshin Akbarzadeh, Nahid Gorjizadeh, Mohammad Hossein Farahani, Behnoosh Teimourian, Pardis Ghafarian, Hamid Sabet, Mohammad Reza Ay
PURPOSE: We developed a high performance portable gamma camera platform dedicated to identification of sentinel lymph nodes (SLNs) and radio-guided surgery for cancer patients. In this work, we present the performance characteristics of SURGEOSIGHT-I, the first version of this platform that can intra-operatively provide high-resolution images of the surveyed areas. METHODS: At the heart of this camera, there is a 43×43 array of pixelated sodium-activated cesium iodide (CsI(Na)) scintillation crystal with 1×1mm(2) pixel size and 5mm thickness coupled to a Hamamatsu H8500 flat-panel multi-anode (64 channels) photomultiplier tube...
July 2016: Physica Medica: PM
Christina Heilmaier, Niklaus Zuber, Dominik Weishaupt
OBJECTIVES: The purpose was to report on the initial experience after implementation of a patient dose-monitoring system in conventional X-ray imaging. METHODS: A dose-monitoring system collected dose data relating to different radiographs (one projection) and studies (two or more projections). Images were acquired on digital X-ray systems equipped with flat-panel detectors. During period 1, examinations were performed in a routine fashion in 12,614 patients. After period 1, technical modifications were performed and radiographers underwent training in radiation protection...
June 23, 2016: European Radiology
P H Richter, J Steinbrener, A Schicho, F Gebhard
INTRODUCTION: Mobile C-arm imaging is commonly used in operating rooms worldwide. Especially in orthopaedic surgery, intraoperative C-arms are used on a daily basis. Because of new minimally-invasive surgical procedures a development in intraoperative imaging is required. The purpose of this article is investigate if the choice of mobile C-arms with flat panel detector technology (Siemens Cios Alpha and Ziehm Vision RFD) influences image quality and dose using standard, commercially available test devices...
August 2016: Injury
Rie Tanaka
Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function...
July 2016: Radiological Physics and Technology
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