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Four dimensional ct

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https://www.readbyqxmd.com/read/29346116/4d-computed-tomography-scans-for-conformal-thoracic-treatment-planning-is-a-single-scan-sufficient-to-capture-thoracic-tumor-motion
#1
Yolanda D Tseng, Landon Wootton, Matthew Nyflot, Smith Apisarnthanarax, Ramesh Rengan, Charles Bloch, George Sandison, Sara St James
Four dimensional computed tomography (4DCT) scans are routinely used in radiation therapy to determine the internal treatment volume for targets that are moving (e.g. lung tumors). The use of these studies has allowed clinicians to create target volumes based upon the motion of the tumor during the imaging study. The purpose of this work is to determine if a target volume based on a single 4DCT scan at simulation is sufficient to capture thoracic motion. Phantom studies were performed to determine expected differences between volumes contoured on 4DCT scans and those on the evaluation CT scans (slow scans)...
January 18, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29341616/stochasticity-of-pores-interconnectivity-in-li-o2-batteries-and-its-impact-on-the-variations-in-electrochemical-performance
#2
Amangeldi Torayev, José Alexis Rucci, Pieter M Magusin, Arnaud Demortiere, Vincent De Andrade, Clare P Grey, Céline Merlet, Alejandro A Franco
While large dispersions in electrochemical performance have been reported for lithium oxygen batteries in the literature, they have not been investigated in any depth. The variability in the results is often assumed to arise from differences in cell design, electrode structure, handling and cell preparation at different times. An accurate theoretical framework turns out to be needed to get a better insight into the mechanisms underneath and to interpreting experimental results. Here, we develop and use a pore network model to simulate the electrochemical performance of three-dimensionally resolved lithium-oxygen cathode mesostructures obtained from TXM nano-computed tomography images...
January 17, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29340290/tailoring-four-dimensional-cone-beam-ct-acquisition-settings-for-fiducial-marker-based-image-guidance-in-radiation-therapy
#3
Peng Jin, Niek van Wieringen, Maarten C C M Hulshof, Arjan Bel, Tanja Alderliesten
Use of four-dimensional cone-beam CT (4D-CBCT) and fiducial markers for image guidance during radiation therapy (RT) of mobile tumors is challenging due to the trade-off among image quality, imaging dose, and scanning time. This study aimed to investigate different 4D-CBCT acquisition settings for good visibility of fiducial markers in 4D-CBCT. Using these 4D-CBCTs, the feasibility of marker-based 4D registration for RT setup verification and manual respiration-induced motion quantification was investigated...
April 2018: Journal of Medical Imaging
https://www.readbyqxmd.com/read/29338969/current-and-future-challenges-of-radiation-oncology-in-iran-a-report-from-the-iranian-society-of-clinical-oncology
#4
A Ameri, M Barzegartahamtan, M Ghavamnasiri, R Mohammadpour, H Dehghan, A Sebzari, K Novin, M Aloosh
AIMS: Growth of the cancer incidence rate in Iran has been very high in recent years. Therefore, the Iranian health care system should be prepared for the treatment of a huge number of patients in the foreseeable future. One of the most important treatment options for cancer is radiation. However, there is no comprehensive information on infrastructure for radiation oncology in this country. MATERIALS AND METHODS: In 2015, a questionnaire was designed by the Iranian Society of Clinical Oncology (ISCO) and all radiation oncology centres in the country were visited to determine four important components of radiation oncology services, including facilities, equipment, personnel and patients...
January 12, 2018: Clinical Oncology: a Journal of the Royal College of Radiologists
https://www.readbyqxmd.com/read/29334769/topographic-analysis-of-the-distal-femoral-condyle-articular-cartilage-surface-adequacy-of-the-graft-from-opposite-condyles-of-the-same-or-different-size-for-the-osteochondral-allograft-transplantation
#5
Adam B Yanke, Atsushi Urita, Jason J Shin, Greg L Cvetanovich, Erin K Moran, Bernard R Bach, Brian J Cole, Nozomu Inoue, Nikhil N Verma
Objective To analyze the topography of the opposite condyle to treat focal femoral condyle articular defects with an osteochondral allograft (OCA). Design Three groups were created: Group 1, same condyle with same width; Group 2, opposite condyle with same width; Group 3, opposite condyle with different width. Computed tomography (CT) of 22 cadaveric femoral hemi-condyles was used to create 3-dimensional CT models that were exported into point-cloud models. Three zones of the donor condyle (anterior, middle, and posterior) were quantified...
January 1, 2018: Cartilage
https://www.readbyqxmd.com/read/29332497/dosimetric-analysis-of-microscopic-disease-in-sbrt-for-lung-cancers
#6
Ronghu Mao, Lingling Tian, You Zhang, Lei Ren, Renqi Gao, Fang-Fang Yin, Hong Ge
OBJECTIVE: The objective of this study is to theoretically and experimentally evaluate the dosimetry in the microscopic disease regions surrounding the tumor under stereotactic body radiation therapy of lung cancer. METHODS: For simplicity, the tumor was considered moving along 1 dimension with a periodic function. The probability distribution function of the tumor position was generated according to the motion pattern and was used to estimate the delivered dose in the microscopic disease region...
December 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/29331298/spatiotemporal-characterization-of-microdamage-accumulation-in-rat-ulnae-in-response-to-uniaxial-compressive-fatigue-loading
#7
Xuhui Zhang, Xiyu Liu, Zedong Yan, Jing Cai, Fei Kang, Shuai Shan, Pan Wang, Mingming Zhai, X Edward Guo, Erping Luo, Da Jing
Repetitive fatigue loading can induce microdamage accumulation in bone matrix, which results in impaired mechanical properties and increased fracture susceptibility. However, the spatial distribution and time-variant process of microdamage accumulation in fatigue-loaded skeleton, especially for linear microcracks which are known to initiate bone remodeling, remain not fully understood. In this study, the time-varying process of the morphology and distribution of microcracks in rat ulnae subjected to uniaxial compressive fatigue loading was investigated...
January 10, 2018: Bone
https://www.readbyqxmd.com/read/29328048/a-biomechanical-modeling-guided-simultaneous-motion-estimation-and-image-reconstruction-technique-smeir-bio-for-4d-cbct-reconstruction
#8
Xiaokun Huang, You Zhang, Jing Wang
Reconstructing four-dimensional cone-beam computed tomography (4D-CBCT) images directly from respiratory phase-sorted traditional 3D-CBCT projections can capture target motion trajectory, reduce motion artifacts, and reduce imaging dose and time. However, the limited numbers of projections in each phase after phase-sorting decreases CBCT image quality under traditional reconstruction techniques. To address this problem, we developed a simultaneous motion estimation and image reconstruction (SMEIR) algorithm, an iterative method that can reconstruct higher quality 4D-CBCT images from limited projections using an inter-phase intensity-driven motion model...
January 12, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29325356/-the-role-and-significance-of-digital-reconstruction-technique-in-liver-segments-based-on-portal-vein-structure
#9
X J Zhou, Q Dong, C Z Zhu, X Chen, B Wei, Y H Duan, J Zhao, X W Hao, H Zhang, P Nie, B Hu, W J Xu, R W Shen, Z H Chen, K R Dong, Y Z Bai, Q Shu, W J Luo, F Gao, N Xia, Q Y Yu
Objective: To study the segment of liver according to the large amount of three-dimensional(3D) reconstructive images of normal human livers and the vascular system, and to recognize the basic functional liver unit based on the anatomic features of the intrahepatic portal veins. Methods: The enhanced CT primitive DICOM files of 1 260 normal human livers from different age groups who treated from October 2013 to February 2017 provided by 16 hospitals were analyzed using the computer-aided surgery system.The 3D liver and liver vascular system were reconstructed, and the digital liver 3D model was established...
January 1, 2018: Zhonghua Wai Ke za Zhi [Chinese Journal of Surgery]
https://www.readbyqxmd.com/read/29322318/total-knee-arthroplasty-with-unexplained-pain-new-insights-from-kinematics
#10
Célia Planckaert, Gabriel Larose, Pierre Ranger, Marc Lacelle, Alexandre Fuentes, Nicola Hagemeister
INTRODUCTION: Up to 20% of total knee arthroplasty patients remain unsatisfied post-surgery, and a large proportion of them report anterior knee pain. This study aims to verify whether patients who experience anterior knee pain after total knee arthroplasty (TKA) will exhibit kinematic characteristics similar to those associated with patellofemoral syndrome, including in the frontal and transverse planes. MATERIALS AND METHODS: Using four different assessment methods [radiological, patient-reported outcome, musculoskeletal assessment with functional performance testing, and a 3D kinematic assessment during gait], the clinical and 3D knee kinematic profiles of three groups were compared: a painful and an asymptomatic TKA group and a healthy control group...
January 10, 2018: Archives of Orthopaedic and Trauma Surgery
https://www.readbyqxmd.com/read/29317142/volumetric-mandibular-change-after-angle-ostectomy-and-outer-cortex-grinding
#11
Jingyi Zhao, Guodong Song, Xianlei Zong, Xiaonan Yang, Le Du, Xiaoshuang Guo, Chenzhi Lai, Zuoliang Qi, Xiaolei Jin
BACKGROUND: Mandibular angle ostectomy is one of the most common surgical procedures for facial contouring in Asian women. However, some patients complain about mandibular angle hypertrophy recurrence after surgery. The present study evaluated volumetric change of the mandible after angle ostectomy and outer cortex grinding. METHODS: Twenty-four patients who underwent bilateral mandibular angle ostectomy and outer cortex grinding from 2013 to 2016 were enrolled...
December 29, 2017: Journal of Cranio-maxillo-facial Surgery
https://www.readbyqxmd.com/read/29306529/comparison-of-gap-volume-after-retrofilling-using-4-different-filling-materials-evaluation-by-micro-computed-tomography
#12
Sue Youn Kim, Hyeon-Cheol Kim, Su-Jung Shin, Euiseong Kim
INTRODUCTION: The purpose of this study was to evaluate the gap volume between dentin and root-end filling materials. METHODS: Four root-end filling materials were compared in the present study: ProRoot MTA (PRM; Dentsply Tulsa Dental, Tulsa, OK), MTA Angelus (MAG; Angelus, Londrina, Brazil), EndoCem MTA (ECM; Maruchi, Wonju, Korea), and RetroMTA (RTM; BioMTA, Seoul, Korea). Forty-eight single-rooted, extracted human teeth were instrumented with nickel-titanium instruments and oburated with gutta-percha...
January 3, 2018: Journal of Endodontics
https://www.readbyqxmd.com/read/29290421/patient-specific-three-dimensional-printing-for-kommerell-s-diverticulum
#13
Xiaoning Sun, Hongqiang Zhang, Kai Zhu, Chunsheng Wang
BACKGROUND: Kommerell's diverticulum is a complex congenital malformation of aorta. Three-dimensional (3D) printing is an innovative manufacturing process that allows computer-assisted conversion of 3D imaging data into physical "printouts." The aim of this study was to explore the feasibility and impact of using patient-specific 3D-printed cardiac prototypes derived from computed tomography data on surgical decision-making and preoperative planning for Kommerell's diverticulum. METHODS: From April to August 2017, five patients with Kommerell's diverticulum were diagnosed and chosen for study...
December 26, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/29290405/ct-ventilation-imaging-derived-from-breath-hold-ct-exhibits-good-regional-accuracy-with-galligas-pet
#14
Enid M Eslick, John Kipritidis, Denis Gradinscak, Mark J Stevens, Dale L Bailey, Benjamin Harris, Jeremy T Booth, Paul J Keall
BACKGROUND AND PURPOSE: CT ventilation imaging (CTVI) derived from four dimensional CT (4DCT) has shown only moderate spatial accuracy in humans due to 4DCT image artefacts. Here we assess the accuracy of an improved CTVI using high quality exhale/inhale breath-hold CT (BHCT). MATERIALS AND METHODS: Eighteen lung cancer patients underwent exhale/inhale BHCT, 4DCT and Galligas PET ventilation scans in a single imaging session. For each BHCT and 4DCT scan, we performed deformable image registration (DIR) between the inhale and exhale phase images to quantify ventilation using three published metrics: (i) breathing induced lung density change, CTVIDIR-HU (ii) breathing induced volume change CTVIDIR-Jac and (iii) the regional air-tissue product, CTVIHU Spatial accuracy was reported as the voxel-wise Spearman correlation r between CTVI and Galligas PET...
December 28, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29283358/four-dimensional-computer-tomography-scans-for-conformal-thoracic-treatment-planning-is-a-single-scan-sufficient-to-capture-thoracic-tumor-motion
#15
Yolanda D Tseng, Landon Scott Wootton, Matthew J Nyflot, Smith Apisarnthanarax, Ramesh Rengan, Charles Bloch, George A Sandison, Sara St James
Four dimensional computed tomography (4DCT) scans are routinely used in radiation therapy to determine the internal treatment volume for targets that are moving (e.g. lung tumors). The use of these studies has allowed clinicians to create target volumes based upon the motion of the tumor during the imaging study. The purpose of this work is to determine if a target volume based on a single 4DCT scan at simulation is sufficient to capture thoracic motion. Phantom studies were performed to determine expected differences between volumes contoured on 4DCT scans and those on the evaluation CT scans (slow scans)...
December 28, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29279160/preoperative-assessment-of-pleural-adhesion-by-four-dimensional-ultra-low-dose-computed-tomography-4d-uldct-with-adaptive-iterative-dose-reduction-using-three-dimensional-processing-aidr-3d
#16
Masayuki Hashimoto, Yukihiro Nagatani, Yasuhiko Oshio, Norihisa Nitta, Tsuneo Yamashiro, Shinsuke Tsukagoshi, Noritoshi Ushio, Masayuki Mayumi, Tatsuya Kimoto, Tomoyuki Igarashi, Makoto Yoshigoe, Kyohei Iwai, Koki Tanaka, Shigetaka Sato, Akinaga Sonoda, Hideji Otani, Kiyoshi Murata, Jun Hanaoka
PURPOSE: To assess the feasibility of Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) for distinguishing pleural aspects with localized pleural adhesion (LPA) from those without. METHODS: Twenty-seven patients underwent 4D-ULDCT during a single respiration with a 16cm-coverage of the body axis. The presence and severity of LPA was confirmed by their intraoperative thoracoscopic findings. A point on the pleura and a corresponding point on the outer edge of the costal bone were placed in identical axial planes at end-inspiration...
January 2018: European Journal of Radiology
https://www.readbyqxmd.com/read/29276406/observation-of-different-tumor-motion-magnitude-within-liver-and-estimate-of-internal-motion-margins-in-postoperative-patients-with-hepatocellular-carcinoma
#17
Yu-Ting Zhao, Zhi-Kai Liu, Qiu-Wen Wu, Jian-Rong Dai, Tao Zhang, Angela Y Jia, Jing Jin, Shu-Lian Wang, Ye-Xiong Li, Wei-Hu Wang
Aims: To assess motion magnitude in different parts of the liver through surgical clips in postoperative patients with hepatocellular carcinoma and to examine the correlation between the clip and diaphragm motion. Methods: Four-dimensional computed tomography images from 30 liver cancer patients under thermoplastic mask immobilization were selected for this study. Three to seven surgical clips were placed in the resection cavity of each patient. The liver volume on computed tomography image was divided into the right upper (RU), right middle (RM), right lower (RL), hilar, and left lobes...
2017: Cancer Management and Research
https://www.readbyqxmd.com/read/29276106/natural-history-of-the-proximal-aorta-in-patients-with-descending-thoracic-aortic-disease
#18
Paul C Tang, Paul D DiMusto, Nilto C De Oliveira, Brooks L Rademacher, Jennifer L Philip, Shahab A Akhter, Charles W Acher
OBJECTIVE: This study investigated the growth and behavior of the ascending aorta in patients with descending thoracic aortic disease. METHODS: We examined 200 patients with descending thoracic aortic disease including acute type B dissection (n = 95), chronic type B dissection (n = 38), intramural hematoma (n = 23), and thoracoabdominal aortic aneurysms (n = 44). Images from computed tomography and magnetic resonance imaging were evaluated after three-dimensional reconstruction to examine the growth rate in those with >1 year of imaging follow-up (n = 108)...
December 21, 2017: Journal of Vascular Surgery
https://www.readbyqxmd.com/read/29275567/-construction-and-assessment-of-a-three-dimensional-finite-element-model-of-mandibualr-second-molar-mesialization-using-customized-lingual-appliance-and-mini-implant
#19
C Chen, C X Wang, J H Yang, L Y Cai, Q G Rong, Y L Zhang
Objective: To construct a three-dimensional (3D) finite element model and analyze the biomechanical characteristics during mandibular second molar mesialization using customized lingual appliances and mini-implant. Methods: One adult student volunteer from The First Affiliated Hospital of Zhengzhou University with lower left first molar extraction was selected. After CT scanning, Mimics, Geomagic, ANSYS were employed to develop a 3D finite element model including customized lingual brackets, stainless steel lingual arch wire, buccal buckles, lower dentition, periodontal ligaments and alveolar bone...
December 9, 2017: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
https://www.readbyqxmd.com/read/29249886/the-use-of-cone-beam-computed-tomography-and-three-dimensional-printing-technology-in-the-restoration-of-a-maxillectomy-patient-using-a-dental-implant-retained-obturator
#20
George Michelinakis
This case report presents an alternative method for fabricating an obturator for patients that develop xerostomia and mild trismus following radiation to the Head and Neck region. Multiple initial impression stages are avoided leading to less irritation to soft tissues and less discomfort to the patient. A 69-year-old male patient was referred to our dental practice by the Maxillofacial Surgery Department of the local General Hospital. The patient had undergone a right maxillectomy for removal of a Squamous Cell Carcinoma 2 weeks prior...
October 2017: Journal of Indian Prosthodontic Society
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