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flat panel detector

Adrien Kaladji, Alexandre Villena, Remy Pascot, Florent Lalys, Anne Daoudal, Elodie Clochard, Antoine Lucas, Alain Cardon
INTRODUCTION: Fusion imaging is a technique that facilitates endovascular navigation but is only available in hybrid rooms. The goal of this study was to evaluate the feasibility of fusion imaging with a mobile C-arm in a conventional operating room through the use of an angio-navigation station. METHODS: From May 2016 to June 2017, the study included all patients who underwent an aortic stent graft procedure in a conventional operating room with a mobile flat-panel detector (Cios Alpha, Siemens) connected to an angio-navigation station (EndoNaut, Therenva)...
August 6, 2018: Annals of Vascular Surgery
Noriyuki Sakai, Katsuyuki Tabei, Jiro Sato, Toshikazu Imae, Yuichi Suzuki, Shigeharu Takenaka, Keiichi Yano, Osamu Abe
OBJECTIVES: To (a) evaluate the interpolation frames of frame rate conversion (FRC) compared with fluoroscopic frames of conventional method, and (b) compare radiation dose and fluoroscopy time between various clinical examinations without and with FRC retrospectively. METHODS: This study consisted of a basic study and a clinical retrospective analysis. The radiation dosimetry, visual assessment and measurements of contrast to noise ratio were examined. Similarity between interpolation frames and fluoroscopic frames was evaluated using normalised cross-correlation values...
July 9, 2018: European Radiology
Keisuke Komiyama, Satoshi Hamai, Daisuke Hara, Satoru Ikebe, Hidehiko Higaki, Kensei Yoshimoto, Kyohei Shiomoto, Hirotaka Gondo, Yifeng Wang, Yasuharu Nakashima
BACKGROUND: The difference in in vivo kinematics before and after total hip arthroplasty (THA) for the same subjects and the clearance between the liner and neck during squatting have been unclear. The purpose of the present study was to clarify (1) the changes in the in vivo kinematics between prosthetic hips and osteoarthritis hips of the same subjects and (2) the extent of the liner-to-neck clearance during squatting under weight-bearing conditions. METHODS: This study consisted of 10 patients who underwent unilateral THA for symptomatic osteoarthritis...
July 3, 2018: Journal of Orthopaedic Surgery and Research
Peter H Richter, Florian Gebhard, Alexander Eickhoff, Konrad Schütze
The invention of flat-panel detectors led to a revolution in medical imaging. The major benefits of this technology are a higher image quality and dose reduction. Flat-panel detectors have proved to be superior to standard C-arms (= C-arm with radiograph source and image intensifier).Cone-beam computed tomography (cone-beam CT) is a 3D data set, which can be acquired with a flat-panel detector. The cone-shaped beam is used for 3D data generation. For cone-beam CT acquisition, the flat-panel detector rotates around the patient lying on the operating table...
May 2018: EFORT Open Reviews
K Egger, C Strecker, E Kellner, H Urbach
There are several automated analytical methods to detect thromboembolic vascular occlusions, the infarct core and the potential infarct-endangered tissue (tissue at risk) by means of multimodal computed tomography (CT) and magnetic resonance imaging (MRI). The infarct core is more reliably visualized by diffusion-weighted imaging (DWI) MRI or CT perfusion than by native CT. The extent of tissue at risk and endangerment can only be estimated; however, it seems essential whether "tissue at risk" actually exists...
June 15, 2018: Der Nervenarzt
Juliaan R M van Rappard, Tijmen de Jong, Willy A Hummel, Marco J P F Ritt, Chantal M Mouës
PURPOSE: During mini C-arm fluoroscopy, both the patient and surgical team are exposed to scatter radiation. The objective of this study was to quantify body, thyroid, and hand radiation exposure to surgeon and assistant during intraoperative use of flat panel mini C-arm fluoroscopy in hand and wrist surgical procedures. METHODS: Over 5 months, the surgeon's and assistant's radiation exposure was recorded during all osseous hand and wrist surgical procedures. Whole-body and thyroid radiation exposure were measured with 2 types of dosimeters: a photon thermoluminescence detector and a RaySafe i2 real-time dosimeter...
June 19, 2018: Journal of Hand Surgery
Zheng Gu, Richard Taschereau, Nam Vu, David L Prout, Robert W Silverman, Jason Lee, Arion F Chatziioannou
G8 is a bench top integrated PET/CT scanner dedicated to high sensitivity and high resolution imaging of mice. This work characterizes its National Electrical Manufacturers Association (NEMA) NU4-2008 performance where applicable and also provides an assessment of the basic imaging performance of the CT subsystem. Methods: The PET subsystem in G8 consists of four flat-panel type detectors arranged in a box like geometry. Each panel consists of two modules of a 26 × 26 pixelated bismuth germanate (BGO) scintillator array with individual crystals measuring 1...
June 14, 2018: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
A R Podgorsak, A C Venkataraman, S V Setlur Nagesh, D R Bednarek, S Rudin, A Siddiqui, C N Ionita
The imaging of endovascular devices during neurovascular procedures such as the coiling of aneurysms guided with CBCT imaging may be challenging due to the presence of highly attenuating materials such as platinum in the coil and stent marker, nickel-titanium in the stent, iodine in the contrast agent, and tantalum in the embolization agent. The use of dual-energy imaging followed by a basis material decomposition image processing-scheme may improve the feature separation and recognition. Two sets of testing were performed to validate this concept...
February 2018: Proceedings of SPIE
S V Setlur Nagesh, A Shankar, J Krebs, J Hinaman, D R Bednarek, S Rudin
Real-time visualization of fine details ranging to 100 um or less in neuro-vascular imaging guided interventions is important. A separate high-resolution detector mounted on a standard flat panel detector (FPD) was previously reported. This device had to be rotated mechanically into position over the FPD for high resolution imaging. Now, the new detector reported here has a high definition (Hi-Def) zoom capability along with the FPD built into one unified housing. The new detector enables rapid switching, by the operator between Hi-Def and FPD modes...
February 2018: Proceedings of SPIE
Ken Chen, Cheng Wang, Jing Xiong, Yaoqin Xie
BACKGROUND: With the introduction of Flat Panel Detector technology, cone-beam CT (CBCT) has become a novel image modality, and widely applied in clinical practices. C-arm mounted CBCT has shown extra suitability in image guided interventional surgeries. During practice, how to acquire high resolution and high quality 3D images with the real time requirement of clinical applications remain challenging. METHODS: In this paper, we propose a GPU based accelerated method for fast C-arm CBCT 3D image reconstructions...
June 5, 2018: Biomedical Engineering Online
N Krah, F Khellaf, J M Létang, S Rit, I Rinaldi
We present a comprehensive analytical comparison of four types of proton imaging set-ups and, to this end, develop a mathematical framework to calculate the width of the uncertainty envelope around the most likely proton path depending on set-up geometry, detector properties, and proton beam parameters. As a figure of merit for the spatial resolution achievable with each set-up, we use the frequency [Formula: see text] at which the modular transfer function of a density step decreases below 10%. We verify the analytical results with Monte Carlo simulations...
July 2, 2018: Physics in Medicine and Biology
A Blum, A Noël, D Regent, N Villani, R Gillet, P Gondim Teixeira
Tomosynthesis is an imaging technique that uses standard X-ray equipment with digital flat panel detectors to create tomographic images from very low-dose projections obtained at different angles. These images are parallel to the plane of the detector. Filtered back-projection or iterative reconstruction algorithms can be used to produce them. Iterative reconstruction used with a metal artifact reduction algorithm reduces metal artifacts, and therefore, improve image quality and in-depth spatial resolution...
May 30, 2018: Diagnostic and Interventional Imaging
Chizuru Okamoto, Yoshie Kodera
We acquired a direct-type flat panel detector (FPD) developed for mammography systems and investigated its physical image properties, as its characteristics may affect future mammography in the clinic. The pixel size of the detector is 50 µm, the smallest size used in clinical mammography. Amorphous selenium (a-Se) film is used in direct-type FPDs. Due to its inferior temperature properties, the temperature of the imaging room should be set to approximately 25 °C. A novel a-Se film with superior heat resistance has been developed by the HAMAMATSU photonics KK Electron Tube Division that is suitable for high electric field driving...
May 29, 2018: Radiological Physics and Technology
Hiroshi Watanabe, Masashi Seki, Masahiro Nitta, Itsuki Serita, Yoshiaki Maehara, Hideaki Okura, Tomofumi Murakami, Kazuyuki Yamamoto, Tsutomu Sato, Ryuto Tajima
The goal of this research was to create the most appropriate index dose for the optimization of protection in medical exposure in general radiography in Kanagawa prefecture. We distributed questionnaires to 272 medical institutions in Kanagawa prefecture. The investigation period was from October 2015 to February 2016. Entrance surface dose (ESD) was used as the index dose. Investigated regions in general radiography were the adult chest, adult abdomen, and infant chest (anterior-posterior projections for all regions)...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
Julian Feulner, Stefan Lang, Thomas Buder, Tobias Struffert, Michael Buchfelder, Sebastian Brandner
BACKGROUND: The standard freehand method for the insertion of external ventricular drains (EVDs) is associated with high rates of incorrect placement. Use of neuronavigation has been shown to reduce the rates of inaccurately positioned EVDs. We present a novel neuronavigation-based approach for EVD placement using flat panel detector computed tomography (FDCT) imaging. METHODS: Four cadaveric heads were used for neuronavigated placement of EVDs using the BrainLAB reference headband in combination with laser surface registration and the precalibrated disposable stylet...
July 2018: World Neurosurgery
Hiraku Iramina, Takumi Hamaguchi, Mitsuhiro Nakamura, Takashi Mizowaki, Ikuo Kanno
We evaluated two dual-energy cone-beam computed tomography (DE-CBCT) methodologies for a bench-top micro-CBCT system to reduce metal artifacts on reconstructed images. Two filter-based DE-CBCT methodologies were tested: (i) alternative spectral switching and (ii) simultaneous beam splitting. We employed filters of 0.6-mm-thick tin and 0.1-mm-thick tungsten to generate high- and low-energy spectra from 120 kVp X-rays, respectively. The spectral switching method was imitated by two half scans with different filters (pseudo-switching)...
July 1, 2018: Journal of Radiation Research
H W Lee, H W Lim, D H Jeon, C K Park, D Y Lee, H S Cho, C W Seo, K S Kim, G A Kim, S Y Park, S Y Kang, J E Park, W S Kim, Y H Lim, T H Woo
In this study, we propose a modification to a single-grid phase-contrast x-ray imaging (PCXI) system using a Fourier domain analysis technique to extract absorption, scattering, and differential phase-contrast images. The proposed modification is to rotate the x-ray grid in the image plane to achieve spectral separation between the desired information and the moiré artifact, which is introduced by the superposition of the periodic image of the grid shadow and the periodic sampling by the detector. In addition, we performed some system optimization by adjusting distances between source, object, grid, and detector to further improve image quality...
June 1, 2018: Computers in Biology and Medicine
Bin Cai, Steven Dolly, Gregory Kamal, Sridhar Yaddanapudi, Baozhou Sun, S Murty Goddu, Sasa Mutic, Hua Li
PURPOSE: To investigate the feasibility of using kV flat panel detector on linac for consistency evaluations of kV x-ray generator performance. METHODS: An in-house designed aluminum (Al) array phantom with six 9 × 9 cm2 square regions having various thickness was proposed and used in this study. Through XML script-driven image acquisition, kV images with various acquisition settings were obtained using the kV flat panel detector. Utilizing pre-established baseline curves, the consistency of x-ray tube output characteristics, including tube voltage accuracy, exposure accuracy and exposure linearity was assessed through image quality assessment metrics including ROI mean intensity, ROI standard deviation (SD), and noise power spectrums (NPS)...
July 2018: Medical Physics
Alisa I Walz-Flannigan, Kimberly J Brossoit, Dayne J Magnuson, Beth A Schueler
Visual familiarity with the variety of digital radiographic artifacts is needed to identify, resolve, or prevent image artifacts from creating issues with patient imaging. Because the mechanism for image creation is different between flat-panel detectors and computed radiography, the causes and appearances of some artifacts can be unique to these different modalities. Examples are provided of artifacts that were found on clinical images or during quality control testing with flat-panel detectors. The examples are meant to serve as learning tools for future identification and troubleshooting of artifacts and as a reminder for steps that can be taken for prevention...
May 2018: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Masayuki Kumashiro, Takahiro Kataoka, Shinobu Yokota, Shinobu Nakagawa, Keisuke Otsuki, Nobuyuki Miyake, Shinji Osumi, Kiyonori Yamaoka
We examined the effects of a reduced exposure dose on the quality of images from an angiography device augmented with a noise reduction algorithm. Before its clinical application, we compared the diameter of the discrimination limit of the hole with that in the conventional method by a visual evaluation with a contrast-detail (C-D) phantom imaged using the target dose. Based on the results, a reducible dose was determined and applied clinically. The sample population consisted of patients being followed up after percutaneous coronary intervention (PCI) for coronary artery disease; we evaluated the effects of the exposure reduction on image quality...
April 2018: Acta Medica Okayama
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