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Flat panel detectors

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https://www.readbyqxmd.com/read/28382313/geometric-calibration-and-correction-for-a-lens-coupled-detector-in-x-ray-phase-contrast-imaging
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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
https://www.readbyqxmd.com/read/28146088/a-ring-artifact-correction-method-validation-by-micro-ct-imaging-with-flat-panel-detectors-and-a-2d-photon-counting-detector
#10
Mohamed Elsayed Eldib, Mohamed Hegazy, Yang Ji Mun, Myung Hye Cho, Min Hyoung Cho, Soo Yeol Lee
We introduce an efficient ring artifact correction method for a cone-beam computed tomography (CT). In the first step, we correct the defective pixels whose values are close to zero or saturated in the projection domain. In the second step, we compute the mean value at each detector element along the view angle in the sinogram to obtain the one-dimensional (1D) mean vector, and we then compute the 1D correction vector by taking inverse of the mean vector. We multiply the correction vector with the sinogram row by row over all view angles...
January 30, 2017: Sensors
https://www.readbyqxmd.com/read/28107246/reliability-and-usefulness-of-intraoperative-3-dimensional-imaging-by-mobile-c-arm-with-flat-panel-detector
#11
Takahito Fujimori, Motoki Iwasaki, Yukitaka Nagamoto, Masafumi Kashii, Masaki Takao, Tsuyoshi Sugiura, Hideki Yoshikawa
STUDY DESIGN: Reliability and agreement study. OBJECTIVE: To assess the reliability of intraoperative 3-dimensional imaging with a mobile C-arm (3D C-arm) equipped with a flat-panel detector. SUMMARY OF BACKGROUND DATA: Pedicle screws are widely used in spinal surgery. Postoperative computed tomography (CT) is the most reliable method to detect screw misplacement. Recent advances in imaging devices have enabled surgeons to acquire 3D images of the spine during surgery...
February 2017: Clinical Spine Surgery
https://www.readbyqxmd.com/read/28102960/nine-degrees-of-freedom-flexmap-for-a-cone-beam-computed-tomography-imaging-device-with-independently-movable-source-and-detector
#12
Peter Keuschnigg, Daniel Kellner, Karl Fritscher, Andrea Zechner, Ulrich Mayer, Philipp Huber, Felix Sedlmayer, Heinz Deutschmann, Philipp Steininger
PURPOSE: Couch-mounted cone-beam computed tomography (CBCT) imaging devices with independently rotatable x-ray source and flat-panel detector arms for acquisitions of arbitrary regions of interest (ROI) have recently been introduced in image-guided radiotherapy (IGRT). This work analyzes mechanical limitations and gravity-induced effects influencing the geometric accuracy of images acquired with arbitrary angular constellations of source and detector in nonisocentric trajectories, which is considered essential for IGRT...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28065378/difference-in-diaphragmatic-motion-during-tidal-breathing-in-a-standing-position-between-copd-patients-and-normal-subjects-time-resolved-quantitative-evaluation-using-dynamic-chest-radiography-with-flat-panel-detector-system-dynamic-x-ray-phrenicography
#13
Yoshitake Yamada, Masako Ueyama, Takehiko Abe, Tetsuro Araki, Takayuki Abe, Mizuki Nishino, Masahiro Jinzaki, Hiroto Hatabu, Shoji Kudoh
OBJECTIVES: To quantitatively compare diaphragmatic motion during tidal breathing in a standing position between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. MATERIALS AND METHODS: Thirty-nine COPD patients (35 males; age, 71.3±8.4years) and 47 normal subjects (non-smoker healthy volunteers) (20 males; age, 54.8±9.8years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system...
February 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28048593/tu-fg-209-10-phantom-simulation-method-to-evaluate-the-clinical-utility-of-the-high-resolution-micro-angiographic-fluoroscope-complementary-metal-oxide-semiconductor-maf-cmos-detector
#14
S Setlur Nagesh, M Russ, C Ionita, D Bednarek, S Rudin
PURPOSE: The purpose of this study is to develop a method to evaluate the clinical utility of a high resolution 75µ pixel MAF-CMOS image receptor compared to a 200µ flat-panel detector (FPD). METHODS: A simulated procedure evaluation method was developed using an aneurysm phantom since every clinical device-deployment procedure is different and to faithfully compare the performance of two detectors in a clinical setting would require the device deployment to be stopped at different stages so that images could be acquired with both detectors...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048545/we-de-207a-04-advances-in-radiological-neuro-endovascular-interventional-imaging
#15
S Rudin
1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introduction of 3D DSA...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048454/we-de-207a-00-advances-in-image-guided-neurointerventions-clinical-pull-and-technology-push
#16
Jeffrey Siewerdsen, Rebecca Fahrig
1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introduction of 3D DSA...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048446/th-ab-209-01-making-benchtop-x-ray-fluorescence-computed-tomography-xfct-practical-for-in-vivo-imaging-by-integration-of-a-dedicated-high-performance-x-ray-source-in-conjunction-with-micro-ct-functionality
#17
N Manohar, F Reynoso, S Cho
PURPOSE: To make benchtop x-ray fluorescence computed tomography (XFCT) practical for routine preclinical imaging tasks with gold nanoparticles (GNPs) by deploying, integrating, and characterizing a dedicated high-performance x-ray source and addition of simultaneous micro-CT functionality. METHODS: Considerable research effort is currently under way to develop a polychromatic benchtop cone-beam XFCT system capable of imaging GNPs by stimulation and detection of gold K-shell x-ray fluorescence (XRF) photons...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048364/we-fg-207a-01-introduction-to-dedicated-breast-ct-early-studies
#18
S Vedantham
Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar "densities", making lesion detection more difficult...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048328/su-g-iep3-03-dual-filament-multi-facet-anode-design-to-overcome-small-focal-spot-output-limitations
#19
E Freund, S Rudin, D Bednarek
PURPOSE: Demonstrate the advantages of two novel x-ray tube-insert designs to overcome tube output limitations for high-resolution, small field-of-view (FOV) angiographic imaging. METHODS: High-spatial resolution with a small focal spot (sfs) is achievable with the microangiographic (MA) detector that we have developed. The two designs explored are a non-offset design, and an offset design. Both tube-insert designs include two filaments, L1 and L2 , and two focal target tracks...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047845/we-ab-207a-01-best-in-physics-imaging-high-resolution-cone-beam-ct-of-the-extremities-and-cancellous-bone-architecture-with-a-cmos-detector
#20
Q Cao, M Brehler, A Sisniega, E Marinetto, A Zyazin, I Peters, J Stayman, J Yorkston, J Siewerdsen, W Zbijewski
PURPOSE: Extremity cone-beam CT (CBCT) with an amorphous silicon (aSi) flat-panel detector (FPD) provides low-dose volumetric imaging with high spatial resolution. We investigate the performance of the newer complementary metal-oxide semiconductor (CMOS) detectors to enhance resolution of extremities CBCT to ∼0.1 mm, enabling morphological analysis of trabecular bone. Quantitative in-vivo imaging of bone microarchitecture could present an important advance for osteoporosis and osteoarthritis diagnosis and therapy assessment...
June 2016: Medical Physics
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