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https://www.readbyqxmd.com/read/29148092/an-inductively-coupled-ultra-thin-flexible-and-passive-rf-resonator-for-mri-marking-and-guiding-purposes-clinical-feasibility
#1
Akbar Alipour, Sayim Gokyar, Oktay Algin, Ergin Atalar, Hilmi Volkan Demir
PURPOSE: The purpose of this study is to develop a wireless, flexible, ultra-thin, and passive radiofrequency-based MRI resonant fiducial marker, and to validate its feasibility in a phantom model and several body regions. METHODS: Standard microfabrication processing was used to fabricate the resonant marker. The proposed marker consists of two metal traces in the shape of a square with an edge length of 8 mm, with upper and lower traces connected to each other by a metalized via...
November 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29146103/assessment-of-the-implant-geometry-in-fractionated-interstitial-hdr-breast-brachytherapy-using-an-electromagnetic-tracking-system
#2
Markus Kellermeier, Rainer Fietkau, Vratislav Strnad, Christoph Bert
PURPOSE: During the partial-breast treatment course by interstitial brachytherapy, electromagnetic tracking (EMT) was applied to measure the implant geometry. Implant-geometry variation, choice of reference data, and three registration methods were assessed. METHODS AND MATERIALS: The implant geometry was measured in 28 patients after catheter implantation (EMTbed), during CT imaging (EMTCT), and in each of up to n = 9 treatment fractions (EMTF(k), k = 1, 2,… n)...
November 13, 2017: Brachytherapy
https://www.readbyqxmd.com/read/29142324/an-algorithm-for-the-beat-to-beat-assessment-of-cardiac-mechanics-during-sleep-on-earth-and-in-microgravity-from-the-seismocardiogram
#3
Marco Di Rienzo, Emanuele Vaini, Prospero Lombardi
Seismocardiogram, SCG, is the measure of precordial vibrations produced by the beating heart, from which cardiac mechanics may be explored on a beat-to-beat basis. We recently collected a large amount of SCG data (>69 recording hours) from an astronaut to investigate cardiac mechanics during sleep aboard the International Space Station and on Earth. SCG sleep recordings are characterized by a prolonged duration and wide heart rate swings, thus a specific algorithm was developed for their analysis. In this article we describe the new algorithm and its performance...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29136287/quantification-of-mri-visibility-and-artefacts-at-3t-of-liquid-fiducial-marker-in-a-pancreas-tissue-mimicking-phantom
#4
Sergej Schneider, Rasmus Irming Jølck, Esther Gera Cornelia Troost, Aswin Louis Hoffmann
PURPOSE: X-ray based position verification of the target volume in image-guided radiation therapy (IGRT) of patients with pancreatic ductal adenocarcinoma (PDAC) is currently performed on solid fiducial markers that are implanted under endoscopic ultrasonography. A new biodegradable liquid fiducial marker has recently been introduced. To assess its potential use for magnetic resonance imaging (MRI) guided photon or proton radiotherapy of PDAC, the MRI visibility and artefacts of this marker were quantified and compared against solid gold markers...
November 14, 2017: Medical Physics
https://www.readbyqxmd.com/read/29125215/additive-manufacturing-a-comparative-analysis-of-dimensional-accuracy-and-skin-texture-reproduction-of-auricular-prostheses-replicas
#5
Alexey Unkovskiy, Sebastian Spintzyk, Detlef Axmann, Eva-Maria Engel, Heiner Weber, Fabian Huettig
PURPOSE: The use of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing in maxillofacial prosthetics has been widely acknowledged. Rapid prototyping can be considered for manufacturing of auricular prostheses. Therefore, so-called prostheses replicas can be fabricated by digital means. The objective of this study was to identify a superior additive manufacturing method to fabricate auricular prosthesis replicas (APRs) within a digital workflow. MATERIALS AND METHODS: Auricles of 23 healthy subjects (mean age of 37...
November 10, 2017: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
https://www.readbyqxmd.com/read/29123458/comparison-of-mri-sequences-in-ideal-fiducial-maker-based-radiotherapy-for-prostate-cancer
#6
Osamu Tanaka, Hisao Komeda, Mitsuyoshi Hattori, Shigeki Hirose, Eiichi Yama, Masayuki Matsuo
Aim: Prostate contouring using CT alone is difficult. To overcome the uncertainty, CT/MRI registration using a fiducial marker is generally performed. However, visualization of the marker itself can be difficult with MRI. This study aimed to determine the optimal MRI pulse sequence for defining the marker as well as the prostate outline among five sequences. Materials and methods: A total of 21 consecutive patients with prostate cancer were enrolled. Two gold fiducial markers were placed before CT/MRI examination...
November 2017: Reports of Practical Oncology and Radiotherapy
https://www.readbyqxmd.com/read/29120662/comparison-of-mri-visualisation-between-linearly-placed-iron-containing-and-non-iron-containing-fiducial-markers-for-prostate-radiotherapy
#7
Osamu Tanaka, Hisao Komeda, Masayoshi Tamaki, Kensaku Seike, Shota Fujimoto, Eiichi Yama, Shigeki Hirose, Masayuki Matsuo
OBJECTIVE: Visualising the gold marker (GM) in CT and MRI is critical, especially for registration in high-precision radiotherapy. GM sizes vary. Large markers are easily visualised in MRI. Small GMs show fewer artefacts in CT but are harder to detect in MRI because the signal is influenced by metal in MRI. Therefore, we compared MRI visualisation between linearly placed new iron-containing marker and non-iron containing marker. METHODS: Twenty-seven patients underwent CT/MRI fusion-based intensity-modulated radiotherapy...
November 9, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/29116058/a-line-fiducial-method-for-geometric-calibration-of-cone-beam-ct-systems-with-diverse-scan-trajectories
#8
Matthew W Jacobson, Michael Daniel Ketcha, Sarah Capostagno, Alexander Martin, Ali Uneri, Joseph Goerres, Tharindu De Silva, Sureerat Reaungamornrat, Runze Han, Amir Manbachi, Joseph Webster Stayman, Sebastian Vogt, Gerhard Kleinszig, Jeffrey H Siewerdsen
Modern cone-beam CT systems, especially C-arms, are capable of diverse source-detector orbits. However, geometric calibration of these systems using conventional configurations of spherical fiducials (BBs) may be challenged for novel source-detector orbits and system geometries. In part, this is because the BB configurations are designed with careful forethought regarding the intended orbit so that BB marker projections do not overlap in projection views. Examples include helical arrangements of BBs (Rougee et al Proc...
November 8, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29114611/2d-kv-orthogonal-imaging-with-fiducial-markers-is-more-precise-for-daily-image-guided-alignments-than-soft-tissue-cone-beam-computed-tomography-for-prostate-radiation-therapy
#9
Peter H Goff, Louis B Harrison, Eli Furhang, Evan Ng, Stephen Bhatia, Frieda Trichter, Ronald D Ennis
Purpose: The hypothesis is that 2-dimensional kV orthogonal imaging with fiducial markers (kV-FM) and soft-tissue cone beam computed tomography (ST-CBCT) are equally reproducible for daily positional alignments for image guided (IG) intensity modulated radiation therapy (IMRT) for prostate cancer. Methods and materials: Ten patients undergoing definitive treatment for prostate cancer with IG-IMRT were imaged daily with kV-FM and ST-CBCT. For each acquired kV and CBCT image, offline alignments to the digitally reconstructed radiograph or planning CT, respectively, were made twice by the same physician to assess intraobserver test-retest reproducibility...
July 2017: Advances in Radiation Oncology
https://www.readbyqxmd.com/read/29094615/a-new-robust-markerless-method-for-automatic-image-to-patient-registration-in-image-guided-neurosurgery-system
#10
Yinlong Liu, Zhijian Song, Manning Wang
BACKGROUND: Compared with the traditional point-based registration in the image-guided neurosurgery system, surface-based registration is preferable because it does not use fiducial markers before image scanning and does not require image acquisition dedicated for navigation purposes. However, most existing surface-based registration methods must include a manual step for coarse registration, which increases the registration time and elicits some inconvenience and uncertainty. METHODS: A new automatic surface-based registration method is proposed, which applies 3D surface feature description and matching algorithm to obtain point correspondences for coarse registration and uses the iterative closest point (ICP) algorithm in the last step to obtain an image-to-patient registration...
November 2, 2017: Computer Assisted Surgery (Abingdon, England)
https://www.readbyqxmd.com/read/29092148/beam-alignment-based-on-two-dimensional-power-spectral-density-of-a-near-field-image
#11
Shenzhen Wang, Qiang Yuan, Fa Zeng, Xin Zhang, Junpu Zhao, Kehong Li, Xiaolu Zhang, Qiao Xue, Ying Yang, Wanjun Dai, Wei Zhou, Yuanchen Wang, Kuixing Zheng, Jingqin Su, Dongxia Hu, Qihua Zhu
Beam alignment is crucial to high-power laser facilities and is used to adjust the laser beams quickly and accurately to meet stringent requirements of pointing and centering. In this paper, a novel alignment method is presented, which employs data processing of the two-dimensional power spectral density (2D-PSD) for a near-field image and resolves the beam pointing error relative to the spatial filter pinhole directly. Combining this with a near-field fiducial mark, the operation of beam alignment is achieved...
October 30, 2017: Optics Express
https://www.readbyqxmd.com/read/29082599/failure-modes-and-effects-analysis-fmea-for-gamma-knife-radiosurgery
#12
Andy Yuanguang Xu, Jagdish Bhatnagar, Greg Bednarz, John Flickinger, Yoshio Arai, Jonet Vacsulka, Wenzheng Feng, Edward Monaco, Ajay Niranjan, L Dade Lunsford, M Saiful Huq
PURPOSE: Gamma Knife radiosurgery is a highly precise and accurate treatment technique for treating brain diseases with low risk of serious error that nevertheless could potentially be reduced. We applied the AAPM Task Group 100 recommended failure modes and effects analysis (FMEA) tool to develop a risk-based quality management program for Gamma Knife radiosurgery. METHODS: A team consisting of medical physicists, radiation oncologists, neurosurgeons, radiation safety officers, nurses, operating room technologists, and schedulers at our institution and an external physicist expert on Gamma Knife was formed for the FMEA study...
October 29, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29076810/cardiorespiratory-coupling-in-the-young-healthy-subjects
#13
Tomasz Sobiech, Teodor Buchner, Paweł Krzesiński, Grzegorz Gielerak
To quantify symptoms of cardiorespiratory interaction in a group of 41 healthy subjects performing a subset of Ewing battery of tests. Approach: We measure empirical distribution of cardiorespiratory coupling time (RI), defined as time from the inspiration onset to the R peaks in the ECG. Study protocol is a subset of Ewing battery of tests. Respiratory function was measured with a thoracic belt and the heart rate was obtained from a two channel ECG measurement. Both series of fiducial points were determined using custom software...
October 27, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/29072317/implanted-fiducial-markers-are-no-longer-needed-for-prostate-cancer-radiotherapy
#14
Christopher F Njeh, Brent C Parker, Colin G Orton
For many decades, it has been common practice to implant fiducial markers within the prostate of patients undergoing radiotherapy in order to enhance the visualization of the target before, during, and after treatment. Some argue that, with the widespread use of cone-beam CT, prostate visualization without the use of fiducial markers is now possible, and such markers are no longer needed. This is the claim debated in this month's Point/Counterpoint. This article is protected by copyright. All rights reserved...
October 26, 2017: Medical Physics
https://www.readbyqxmd.com/read/29069299/a-fast-fiducial-marker-tracking-model-for-fully-automatic-alignment-in-electron-tomography
#15
Renmin Han, Fa Zhang, Xin Gao
Motivation: Automatic alignment, especially fiducial marker-based alignment, has become increasingly important due to the high demand of subtomogram averaging and the rapid development of large-field electron microscopy. Among the alignment steps, fiducial marker tracking is a crucial one that determines the quality of the final alignment. Yet, it is still a challenging problem to track the fiducial markers accurately and effectively in a fully automatic manner. Results: In this paper, we propose a robust and efficient scheme for fiducial marker tracking...
October 23, 2017: Bioinformatics
https://www.readbyqxmd.com/read/29065613/r-peak-detection-method-using-wavelet-transform-and-modified-shannon-energy-envelope
#16
Jeong-Seon Park, Sang-Woong Lee, Unsang Park
Rapid automatic detection of the fiducial points-namely, the P wave, QRS complex, and T wave-is necessary for early detection of cardiovascular diseases (CVDs). In this paper, we present an R peak detection method using the wavelet transform (WT) and a modified Shannon energy envelope (SEE) for rapid ECG analysis. The proposed WTSEE algorithm performs a wavelet transform to reduce the size and noise of ECG signals and creates SEE after first-order differentiation and amplitude normalization. Subsequently, the peak energy envelope (PEE) is extracted from the SEE...
2017: Journal of Healthcare Engineering
https://www.readbyqxmd.com/read/29063277/3d-2d-registration-in-endovascular-image-guided-surgery-evaluation-of-state-of-the-art-methods-on-cerebral-angiograms
#17
Uroš Mitrović, Boštjan Likar, Franjo Pernuš, Žiga Špiclin
PURPOSE: Image guidance for minimally invasive surgery is based on spatial co-registration and fusion of 3D pre-interventional images and treatment plans with the 2D live intra-interventional images. The spatial co-registration or 3D-2D registration is the key enabling technology; however, the performance of state-of-the-art automated methods is rather unclear as they have not been assessed under the same test conditions. Herein we perform a quantitative and comparative evaluation of ten state-of-the-art methods for 3D-2D registration on a public dataset of clinical angiograms...
October 24, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/29059939/development-of-semi-automatic-procedure-for-detection-and-tracking-of-fiducial-markers-for-orofacial-kinematics-during-natural-feeding
#18
Filiz Bunyak, Naru Shiraishi, Kannappan Palaniappan, Teresa E Lever, Limor Avivi-Arber, Kazutaka Takahashi
Feeding is a highly complex, essential behavior for survival in all species. Characterization of feeding behaviors has implications in basic science and translational medicine. We have been developing methods to study feeding behaviors using high speed videofluoroscopy (XROMM) in rats while self-feeding radiopaque flavored kibble. The rat is a popular model in translational medicine; however, it has not been studied using this methodology. Towards this goal, we surgically implanted radiopaque fiducial markers into the skull, mandible, and tongue of rats to enable motion tracking...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29056556/injectable-iodine-125-labeled-tissue-marker-for-radioactive-localization-of-non-palpable-breast-lesions
#19
Henrik Schaarup-Jensen, Andreas Ingemann Jensen, Anders Elias Hansen, Henrik H El Ali, Peter Hammershøj, Rasmus Irming Jølck, Andreas Kjær, Thomas L Andresen, Mads H Clausen
We have developed a (125)I-radiolabeled injectable fiducial tissue marker with the potential to replace current methods used for surgical guidance of non-palpable breast tumors. Methods in routine clinical use today such as radioactive seed localization, radio-guided occult lesion localization and wire-guided localization suffers from limitations that this injectable fiducial tissue marker offers solutions to. The developed (125)I-radiolabeled injectable fiducial tissue marker is based on highly viscous sucrose acetate isobutyrate...
October 19, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/29053107/spectral-imaging-using-clinical-megavoltage-beams-and-a-novel-multi-layer-imager
#20
Marios E Myronakis, Rony Fueglistaller, Joerg Rottmann, Yue-Houng Hu, Adam Wang, Paul Baturin, Pascal Huber, Daniel Morf, Josh M Star-Lack, Ross I Berbeco
We assess the feasibility of clinical megavoltage (MV) spectral imaging for material and bone separation with a novel multi-layer imager (MLI) prototype. The MLI provides higher detective quantum efficiency and lower noise than conventional electronic portal imagers. Simulated experiments were performed using a validated Monte Carlo model of the MLI to estimate energy absorption and energy separation between the MLI components. Material separation was evaluated experimentally using solid water and aluminum (Al), copper (Cu) and gold (Au) for 2...
October 20, 2017: Physics in Medicine and Biology
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