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Cone beam CT

Xiangyang Tang, Elizabeth A Krupinski, Huiqiao Xie, Arthur E Stillman
PURPOSE: In the clinic, CT has evolved into an essential modality for diagnostic imaging by MDCT and image guided intervention by CBCT. Recognizing the increasing importance of axial MDCT/CBCT in clinical and preclinical applications, and the existence of CB artifacts in MDCT/CBCT images, we provide a review of CB artifacts' root causes, rendering mechanisms and morphology, and possible solutions for elimination and/or reduction of the artifacts. METHODS: By examining the null space in Radon and Fourier domain, the root cause of CB artifacts (i...
July 17, 2018: Medical Physics
Samendra Prasad, Matthew Podgorsak, Robert Plunkett, Dheerendra Prasad
Background: Thermoplastic mask immobilization is used to perform hypo-fractionated treatments with the Gamma Knife ICON®. Materials and methods: We evaluated the curing characteristics of the ICON® Nanor mask using force sensing resistors coupled with a data logging tool designed by us. Results: For patients being treated with masks made the same day as the treatment, often in the same sitting with no removal and replacement of the patient from the treatment cradle, based on the curves 80% of the force of fixation is reached at 30 minutes...
June 2018: Radiology and Oncology
Marco Ertreo, Hailey Choi, David Field, Jonathan W Lischalk, Emil Cohen, George E Lynskey, Theresa Caridi, Donna Buckley, Keith Unger, Alexander Y Kim
PURPOSE: To compare the use of cone-beam computed tomography versus contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the calculation of liver volume and planned dose for yttrium-90 radioembolization. MATERIALS AND METHODS: The study retrospectively assessed 47 consecutive patients who underwent resin Y-90 radioembolization consecutively over a 2-year period at a single center. Volume calculation software was used to determine perfused lobar liver volumes from cone-beam CT (CBCT) images obtained during mapping angiography...
July 13, 2018: Cardiovascular and Interventional Radiology
Arash Navran, Wilma Heemsbergen, Tomas Janssen, Olga Hamming-Vrieze, Marcel Jonker, Charlotte Zuur, Marcel Verheij, Peter Remeijer, Jan-Jakob Sonke, Michiel van den Brekel, Abrahim Al-Mamgani
BACKGROUND AND PURPOSE: In recent decades, outcomes of patients with head and neck cancer (HNC) have improved as a result of implementing several strategies, such as chemoradiation. However, these improvements were achieved at the cost of increased toxicity. One way to reduce radiation-related toxicity is by reducing the margins. MATERIALS AND METHODS: Between 2013 and 2016, 206 consecutive patients were treated with CTV-PTV margin of 5 mm and subsequently 208 patients with 3 mm margin...
July 10, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Robyn Melanie Benz, Dorothee Harder, Felix Amsler, Johannes Voigt, Andreas Fieselmann, Anna Lucja Falkowski, Bram Stieltjes, Anna Hirschmann
OBJECTIVES: The aims of this study were to assess feasibility, image quality, and radiation dose and to estimate the optimal dose protocol for the lumbar spine of cadaveric specimens with different body mass indices (BMIs) in the upright position using a prototype 3-dimensional cone-beam computed tomography (CT) software implemented on a robotic x-ray system and compare with CT. MATERIALS AND METHODS: The lumbar spine of 5 formalin-fixed human cadaveric specimens (BMI, 22-35 kg/m) was prospectively assessed in the upright position using prototype software for 3-dimensional tomography implemented on a robotic x-ray system...
July 12, 2018: Investigative Radiology
S Wang, J Sun, Y Y Yu
Objective: To study the influence of two-wall bone defect on periodontal ligament stresses under normal occlusal forces, and to analyze the influence of depth and width of bone defect to periodontal ligament stresses. Methods: Three-dimensional finite element models of teeth, periodontal ligament and alveolar bone were created based on cone beam CT images. Proximal two-wall bone defect with different depths (bone defect occupies one third, two thirds, and full length of root) and widths (bone defect occupies one fourth, two fourths, three fourths and full width of buccal lingual width) were simulated by modifying the elastic modulus of elements within defect areas...
July 9, 2018: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
X D Zhuang, W X Chen, C Q Mao, Q J Xu, W H Chen
Objective: To classify the morphology of mandible posterior region and provide reference for the planning of dental implantation. Methods: Cone beam CT data of 208 patients were collected. The CT data were imported into CS 3D imaging V3 software and then the morphology of mandible posterior region were analyzed. The types of premolar and molar mandible cross-section morphology were recorded, classified and analyzed. Results: The results showed that type A (vertical type) (79%-96%) was the most common in the premolars, whereas type B (inclined type) (36%-37%) and type C (lingual inverted concave) (30%-54%) were the most common types in the molars, followed type D (absorption severe type) (2%-5%)...
July 9, 2018: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Yunsong Zhao, Jinqiu Xu, Hongwei Li, Peng Zhang
Computed laminography (CL) is a prospective nondestructive testing technique for flat object inspection in industrial applications. However, CL image reconstruction is a challenging task because incomplete projection data are acquired from the CL scan. When a conventional computed tomography (CT) reconstruction method is applied to cone beam CL data, the vertical edges (singularities in the z-direction) in the reconstructed image would be blurred. On the contrary, the horizontal edges (singularities within slices) can be quite accurately reconstructed...
June 7, 2018: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Shiras Abdurahman, Robert Frysch, Richard Bismark, Steffen Melnik, Oliver Beuing, Georg Rose
The polychromatic X-ray spectrum and the energydependent attenuation coefficient of materials cause beam hardening artifacts in CT reconstructed volumes. These artifacts appear as cupping and streak artifacts depending on the material composition and the geometry of the imaged object. CT scanners employ projection linearization to transform polychromatic attenuation to monochromatic attenuation using a polynomial model. Polynomial coefficients are computed during calibration or using prior information such as X-ray spectrum and attenuation properties of the materials...
May 24, 2018: IEEE Transactions on Medical Imaging
David Asher, Kyle R Padgett, Ricardo E Llorente, Benjamin S Farnia, John C Ford, Shefali R Gajjar, Shahil Mehta, Garrett N Simpson, Nesrin Dogan, Lorraine Portelance
Radiation treatment verification has improved significantly over the past decades. The field has moved from film X-rays and skin marks to fiducial tracking and daily cone beam computed tomography (CBCT) for tumor localization. We now have the ability to perform daily on-board magnetic resonance imaging (MRI), which provides superior soft tissue contrast compared to computed tomography (CT). In the management of cervical cancer, the brachytherapy literature has demonstrated that MRI allows for better delineation of the high-risk clinical target volume (HR-CTV) and the use of MRI-guided brachytherapy has translated into improved treatment outcomes...
May 4, 2018: Curēus
Christian Doll, Nadine Thieme, Stefanie Schönmuth, Jan Oliver Voss, Susanne Nahles, Benedicta Beck-Broichsitter, Max Heiland, Jan-Dirk Raguse
PURPOSE: Despite the advantages and broad applications of alloplastic resorbable implants, postoperative radiological control is challenging due to its radiolucency. The aim of the present study was to evaluate the radiographic visibility of newly developed materials for orbital floor reconstruction. MATERIALS AND METHODS: The radiographic visibility of four different material combinations consisting of poly-(L-lactic acid)/poly-glycolic acid (PLLA/PGA) or poly(D,L-lactic acid) (PDLLA) enriched with magnesium (Mg), hydroxyapatite (HA) or β-tricalcium phosphate (β-TCP) with various layers of thicknesses (0...
May 31, 2018: Journal of Cranio-maxillo-facial Surgery
Qiang Liu, Jian Liang, Dingyi Zhou, Daniel J Krauss, Peter Y Chen, Di Yan
PURPOSE: Four-dimensional (4D) adaptive radiation therapy (ART) treatment planning is an alternative to the conventional margin-based treatment planning approach. In 4D ART, interfraction patient geometric variations, gathered from computed tomography (CT) or cone beam CT (CBCT) images acquired during the patient treatment course, are directly incorporated into the adaptive plan optimization using a probabilistic treatment planning method. The goal of the present planning study was to evaluate the dosimetric differences between 4D ART and conventional margin-based adaptive planning strategies for head and neck cancers...
July 15, 2018: International Journal of Radiation Oncology, Biology, Physics
Brent van der Heyden, Mark Podesta, Lotte Ejr Schyns, Ana Vaniqui, Isabel P Almeida, Stefan J van Hoof, Daniëlle Bp Eekers, Frank Verhaegen
OBJECTIVE: During the treatment planning of a preclinical small animal irradiation, which has time limitations for reasons of animal wellbeing and workflow efficiency, the time consuming organ at risk (OAR) delineation is performed manually. This work aimed to develop, demonstrate, and quantitatively evaluate an automated contouring method for six OARs in a preclinical irritation treatment workflow. METHODS: Micro cone-beam CT images of nine healthy mice were contoured with an in-house developed multi atlas based image segmentation (MABIS) algorithm for six OARs: kidneys, eyes, heart, and brain...
July 5, 2018: British Journal of Radiology
Dominik F Vollherbst, Ruth Otto, Thuy Do, Hans U Kauczor, Martin Bendszus, Christof M Sommer, Markus A Möhlenbruch
Background and purpose A frequently reported drawback of ethylene vinyl alcohol copolymer-based liquid embolic agents is the production of artifacts in diagnostic imaging. New embolic agents, such as Precipitating hydrophobic injectable liquid (PHIL; MicroVention, Tustin, CA, USA), are supposed to induce significantly fewer artifacts. The purpose of this study is to assess the degree of artifacts induced by the liquid embolic agents Onyx (Medtronic Neurovascular, Irvine, CA, USA) and PHIL in conventional computed tomography (CT), cone-beam CT and magnetic resonance imaging (MRI) in an experimental in vivo model...
January 1, 2018: Interventional Neuroradiology
Y X Zhang, Y H Wu, D S Yao, J Y Yang, L Gao
Objective: To compare the influence of extraction and retention of the intruded dogs' teeth on permanent successors. Methods: Nine healthy 45-days-old Chinese rural puppies were selected, and six were submitted to the intrusion of the bilateral canine. Intruded teeth on the left side were extracted 30 minutes later and the teeth on the right side were kept in their sockets. After 8 months, all dogs were sacrificed. General observation, periapical radiograph and cone beam CT were used to observe the preoperative and postoperative deciduous teeth, permanent germs and permanent teeth development...
May 9, 2018: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
X T Jia, X F Huang
Objective: To investigate the soft and hard tissue morphology in the infrazygomatic crest zone by observing the cone-beam computed tomography (CBCT) scans in patients with mini-implants. Methods: CBCT scans of 43 patients performed from January 2014 to December 2016 in the Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, with 84 existing mini-implants in the infrazygomatic crest region were collected. The bone thickness and cortical bone thickness were measured in the palatal and buccal side of the mini-implant...
January 9, 2018: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Z Huang, G S Huang, J Wu, T Sang
Objective: To assess the mandibular condylar growth using cone-beam CT (CBCT) in beagle dogs treated with Herbst appliance and exogenous prostaglandin E2 (PGE2) during late stage of growth. Methods: Twenty-four male beagle dogs aged 8 months were divided into four groups according to the random number table ( n= 6 in each group): natural growth group, mandibular protraction group (Herbst group), injected prostaglandin E2 group (PGE2 group), mandibular protraction plus injected prostaglandin E2 group (Herbst+PGE2 group)...
November 9, 2017: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
M H Wang, Z L Ge, L Tian, P R Li, Y Q Che
Objective: To evaluate the transverse displacement, stress distribution and tendency of change in tooth, alveolar bone and mid-palatal suture using three kinds of rapid maxillary expansion methods. Methods: Cone-beam CT image data was obtained by scanning skulls of a volunteer. Three-dimensional models of maxillary complex were re-established using Mimics and Geomagic Studio and models of Hyrax expander, Haas expander and miniscrew-assisted rapid palatal expander (MARPE) were established using ANSYS Workbench...
November 9, 2017: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Y Li, C Sun, H Jia, X J Luo
Objective: To evaluate the effect of different placement of mesial implants in edentulous jaws on the stress of the implant and the surrounding bone tissue by three-dimensional (3D)finite element analysis. Methods: Cone-beam CT data of mandibular edentulous patients was transferred into Mimics 17.0 and UG NX8.5 software, and three groups of 3D solid model were established: two mesial implants were implanted in the anterior region of the mandible (bilateral central incisor, lateral incisor, canine), and two distal oblique implant with 30° were implanted in the mandibular second premolar area(5 mm near the mental foramen)...
November 9, 2017: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Z Wang, L Zhou, D L Xu, S L Xu
Objective: To examine the root position of the maxillary central incisors and to provide clinical reference before the immediate implant placement. Methods: Cone-beam CT (CBCT) data of the maxillary central incisors of 934 patients (934 incisors) was selected and the root position classsified. The sagittal root position in the alveolar bone was classified as buccal, middle, or palatal. The buccally positoined type was further classified into three subtypes of Ⅰ,Ⅱ, and Ⅲ. Results: Most of the maxillary incisor root (95...
November 9, 2017: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
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