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Four dimensional ct

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https://www.readbyqxmd.com/read/28300381/comparison-of-ct-images-with-average-intensity-projection-free-breathing-and-mid-ventilation-for-dose-calculation-in-lung-cancer
#1
Chirasak Khamfongkhruea, Sangutid Thongsawad, Chirapha Tannanonta, Sasikarn Chamchod
The purpose of this study was to compare three computed tomography (CT) images under different conditions-average intensity projection (AIP), free breathing (FB), mid-ventilation (MidV)-used for radiotherapy contouring and planning in lung cancer patients. Two image sets derived from four-dimensional CT (4DCT) acquisition (AIP and MidV) and three-dimensional CT with FB were generated and used to plan for 29 lung cancer patients. Organs at risk (OARs) were delineated for each image. AIP images were calculated with 3D conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT)...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28300367/4d-vmat-planning-and-verification-technique-for-dynamic-tracking-using-a-direct-aperture-deformation-dad-method
#2
Yongqian Zhang, Yong Yang, Weihua Fu, Xiang Li, Tianfang Li, Dwight E Heron, M Saiful Huq
We developed a four-dimensional volumetric modulated arc therapy (4D VMAT) planning technique for moving targets using a direct aperture deformation (DAD) method and investigated its feasibility for clinical use. A 3D VMAT plan was generated on a reference phase of a 4D CT dataset. The plan was composed of a set of control points including the beam angle, MLC apertures and weights. To generate the 4D VMAT plan, these control points were assigned to the closest respiratory phases using the temporal information of the gantry angle and respiratory curve...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28294203/accuracy-and-reproducibility-of-four-cone-beam-computed-tomography-devices-using-3d-implant-planning-software
#3
Michael Stimmelmayr, Katharina Denk, Kurt Erdelt, Gerald Krennmair, Sonia Mansour, Florian Beuer, Jan-Frederik Güth
OBJECTIVE: To measure the deviations of four different cone beam computed tomography (CBCT) devices in three dimensions by means of a three-dimensional (3D) implant-planning program. MATERIALS AND METHODS: A master radiographic template with two vertical, two transverse, and two sagittal radiopaque markers was fabricated for a human dry skull. The lengths of the markers were measured with a high-precision caliper. The skull and the template were scanned in each of the four CBCT devices (1...
2017: International Journal of Computerized Dentistry
https://www.readbyqxmd.com/read/28291918/organ-motion-in-pediatric-high-risk-neuroblastoma-patients-using-four-dimensional-computed-tomography
#4
Sneha Kannan, Boon-Keng Kevin Teo, Timothy Solberg, Christine Hill-Kayser
PURPOSE/OBJECTIVE(S): High-risk neuroblastoma (HR-NBL) requires multimodality treatment, including external beam radiation of the primary tumor site following resection. Radiotherapy planning must take into account motion of the target and adjacent normal anatomy, both of which are poorly understood in the pediatric population, and which may differ significantly from those in adults. METHODS/MATERIALS: We examined 4DCT scans of 15 consecutive pediatric patients treated for HR-NBL, most with tumors in the abdominal cavity...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28281316/development-and-psychometric-properties-of-the-nursing-critical-thinking-in-clinical-practice-questionnaire
#5
Esperanza Zuriguel-Pérez, Anna Falcó-Pegueroles, Juan Roldán-Merino, Sandra Agustino-Rodriguez, Maria Del Carmen Gómez-Martín, Maria Teresa Lluch-Canut
BACKGROUND AND AIM: A complex healthcare environment, with greater need for care based on the patient and evidence-based practice, are factors that have contributed to the increased need for critical thinking in professional competence. At the theoretical level, Alfaro-LeFevre () put forward a model of critical thinking made up of four components. And although these explain the construct, instruments for their empirical measurement are lacking. The purpose of the study was to develop and validate the psychometric properties of an instrument, the Nursing Critical Thinking in Clinical Practice Questionnaire (N-CT-4 Practice), designed to evaluate the critical thinking abilities of nurses in the clinical setting...
March 9, 2017: Worldviews on Evidence-based Nursing
https://www.readbyqxmd.com/read/28279435/three-dimensional-characterization-and-distribution-of-fabrication-defects-in-bilayered-lithium-disilicate-glass-ceramic-molar-crowns
#6
Yutao Jian, Zi-Hua He, Li Dao, Michael V Swain, Xin-Ping Zhang, Ke Zhao
OBJECTIVE: To investigate and characterize the distribution of fabrication defects in bilayered lithium disilicate glass-ceramic (LDG) crowns using micro-CT and 3D reconstruction. METHODS: Ten standardized molar crowns (IPS e.max Press; Ivoclar Vivadent) were fabricated by heat-pressing on a core and subsequent manual veneering. All crowns were scanned by micro-CT and 3D reconstructed. Volume, position and sphericity of each defect was measured in every crown. Each crown was divided into four regions-central fossa (CF), occlusal fossa (OF), cusp (C) and axial wall (AW)...
March 6, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
https://www.readbyqxmd.com/read/28276077/quantifying-the-reproducibility-of-lung-ventilation-images-between-4-dimensional-cone-beam-ct-and-4-dimensional-ct
#7
Henry C Woodruff, Chun-Chien Shieh, Fiona Hegi-Johnson, Paul J Keall, John Kipritidis
PURPOSE: Deformable image registration (DIR) based computed tomography ventilation imaging derived from four-dimensional cone-beam CT (CTVI(4)(DCBCT) ) can complement existing 4DCT-based methods (CTVI(4)(DCT) ) to track lung function changes over a course of lung cancer radiation therapy. However the accuracy of CTVI(4)(DCBCT) needs to be assessed since anatomic 4DCBCT has demonstrably poor image quality and small field of view (FOV) compared to treatment planning 4DCT. We perform a direct comparison between short interval CTVI(4)(DCBCT) and CTVI(4)(DCT) pairs to understand the patient specific image quality factors affecting the intermodality CTVI reproducibility in the clinic...
March 9, 2017: Medical Physics
https://www.readbyqxmd.com/read/28271696/folate-deficiency-and-gene-polymorphisms-of-mthfr-mtr-and-mtrr-elevate-the-hyperhomocysteinemia-risk
#8
Wen-Xing Li, Fei Cheng, A-Jie Zhang, Shao-Xing Dai, Gong-Hua Li, Wen-Wen Lv, Tao Zhou, Qiang Zhang, Hong Zhang, Tao Zhang, Fang Liu, Dahai Liu, Jing-Fei Huang
BACKGROUND: Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular diseases (CVDs). We aimed to investigate the joint effect of homocysteine metabolism gene polymorphisms, as well as the folate deficiency on the risk of HHcy in a Chinese hypertensive population. METHODS: This study enrolled 480 hypertensive patients aged 28 - 75 from six hospitals in different Chinese regions from 9/2005 - 12/2005. Known genotypes of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G were detected by PCRRFLP methods...
March 1, 2017: Clinical Laboratory
https://www.readbyqxmd.com/read/28260811/a-4dct-imaging-based-breathing-lung-model-with-relative-hysteresis
#9
Shinjiro Miyawaki, Sanghun Choi, Eric A Hoffman, Ching-Long Lin
To reproduce realistic airway motion and airflow, the authors developed a deforming lung computational fluid dynamics (CFD) model based on four-dimensional (4D, space and time) dynamic computed tomography (CT) images. A total of 13 time points within controlled tidal volume respiration were used to account for realistic and irregular lung motion in human volunteers. Because of the irregular motion of 4DCT-based airways, we identified an optimal interpolation method for airway surface deformation during respiration, and implemented a computational solid mechanics-based moving mesh algorithm to produce smooth deforming airway mesh...
December 1, 2016: Journal of Computational Physics
https://www.readbyqxmd.com/read/28247113/management-of-eosinophilic-granuloma-in-pediatric-patients-surgical-intervention-and-surgery-combined-with-postoperative-radiotherapy-and-or-chemotherapy
#10
Zhenhai Zhou, Hongqi Zhang, Chaofeng Guo, Honggui Yu, Longjie Wang, Qiang Guo
BACKGROUND: Eosinophilic granuloma (EG) of spine in pediatric patients presents kinds of clinical manifestation and a difficult management scenario. The choice of treatment, issues of surgical intervention versus conservative treatment, combination therapy or single treatment, all these factors, including neurological deficits, spinal stability, long-term complications, and continued skeletal growth, must be considered. METHODS: From 2008 to the 2015, 31 pediatric patients of spinal EG were retrospectively reviewed...
February 28, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
https://www.readbyqxmd.com/read/28245365/a-robust-method-to-extract-the-anterior-pelvic-plane-from-ct-volume-independent-of-pelvic-pose
#11
Changhwan Lee, Yeesuk Kim, Hyung Wook Kim, Young Soo Kim, Jongseong Jang
PURPOSE: The anterior pelvic plane (APP) is commonly used as a reference plane to assess acetabular orientation. However, conventional methods for determining the APP may not be accurate and are prone to user variability. To overcome these issues, we developed a robust method to accurately extract the APP independent of pelvic pose using three-dimensional pelvic computed tomography (CT). MATERIALS AND METHODS: Twenty-eight studies for suspected nonmusculoskeletal conditions were obtained...
December 2017: Comput Assist Surg (Abingdon)
https://www.readbyqxmd.com/read/28244908/the-relationship-between-acl-femoral-tunnel-position-and-postoperative-mri-signal-intensity
#12
Se Min Lee, Kyoung Ho Yoon, Sang Hak Lee, Dong Hur
BACKGROUND: The purpose of this study was to find the ideal femoral tunnel position in single-bundle anterior cruciate ligament (ACL) reconstruction using three-dimensional computed tomography (3D-CT) by comparing clinical scores, stability of the knee joint, and graft signal intensity on follow-up magnetic resonance imaging (MRI). We hypothesized that positioning the femoral tunnel near the anteromedial bundle or center would lead to better results in terms of clinical outcomes and graft signal intensity on follow-up MRI than would positioning the tunnel near the posterolateral bundle...
March 1, 2017: Journal of Bone and Joint Surgery. American Volume
https://www.readbyqxmd.com/read/28243844/3d-spect-ct-fusion-using-image-data-projection-of-bone-spect-onto-3d-volume-rendered-ct-images-feasibility-and-clinical-impact-in-the-diagnosis-of-bone-metastasis
#13
Yuji Ogata, Tadaki Nakahara, Kenichi Ode, Yohji Matsusaka, Mari Katagiri, Yu Iwabuchi, Kazunari Itoh, Akira Ichimura, Masahiro Jinzaki
PURPOSE: We developed a method of image data projection of bone SPECT into 3D volume-rendered CT images for 3D SPECT/CT fusion. The aims of our study were to evaluate its feasibility and clinical usefulness. METHODS: Whole-body bone scintigraphy (WB) and SPECT/CT scans were performed in 318 cancer patients using a dedicated SPECT/CT systems. Volume data of bone SPECT and CT were fused to obtain 2D SPECT/CT images. To generate our 3D SPECT/CT images, colored voxel data of bone SPECT were projected onto the corresponding location of the volume-rendered CT data after a semi-automatic bone extraction...
February 27, 2017: Annals of Nuclear Medicine
https://www.readbyqxmd.com/read/28238577/geometrical-and-dosimetrical-uncertainties-in-hypofractionated-radiotherapy-of-the-lung-a-review
#14
REVIEW
Marco Schwarz, Giovanni Mauro Cattaneo, Livia Marrazzo
The application of high precision hypofractionated regimes (a.k.a. stereotactic body radiotherapy (SBRT)) to the treatment of lung cancer is a 'success story' of radiotherapy. From the technical perspective, lung SBRT is a challenging technique as all aspects of the treatment workflow, from imaging to dose calculation to treatment delivery, should be carefully handled in order to ensure consistency between planned and delivered dose. In this review such technical aspects are presented and discussed, looking at what has been developed over the years...
February 23, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28237430/evaluation-of-impact-of-an-external-breast-shield-flexishield-in-electronic-brachytherapy-for-breast-iort-a-phantom-study
#15
Yongbok Kim, Jason Wei-Yeong Huynh, Victor J Gonzalez
PURPOSE: To investigate Axxent (iCAD, Inc., San Jose, CA) electronic brachytherapy balloon deformation and its dosimetric impact because of an external flexible shield (FlexiShield [FS]; iCAD, Inc.). METHODS AND MATERIALS: Prostheses breast tissue phantom overlaid three spherical balloon applicators to simulate three clinical scenarios depending on minimum skin-to-balloon surface spacing (SS): balloon with SS of 2 cm, 1 cm, and balloon with 1 cm SS and touching the chest wall...
February 23, 2017: Brachytherapy
https://www.readbyqxmd.com/read/28225778/gnb3-and-creb1-gene-polymorphisms-combined-with-negative-life-events-increase-susceptibility-to-major-depression-in-a-chinese-han-population
#16
Jingsong Ma, Lin Wang, Yanjie Yang, Zhengxue Qiao, Deyu Fang, Xiaohui Qiu, Xiuxian Yang, Xiongzhao Zhu, Jincai He, Hui Pan, Bo Ban, Yan Zhao, Hong Sui
BACKGROUND: Major depression (MD) is caused by a combination of genetic and environmental factors. In this study we investigated the interaction of variations in the G-protein beta 3 subunit (GNB3) and cAMP response element binding protein 1 (CREB1) genes with negative life events in the pathogenesis of MD. One GNB3 polymorphism (rs5443) and four CREB1 polymorphisms (rs2253206, rs2551941, rs6740584, rs11904814) were investigated based on known associations with MD. METHODS: 512 patients with MD and 513 control subjects were genotyped...
2017: PloS One
https://www.readbyqxmd.com/read/28216331/development-of-a-four-dimensional-monte-carlo-dose-calculation-system-for-real-time-tumor-tracking-irradiation-with-a-gimbaled-x-ray-head
#17
Yoshitomo Ishihara, Mitsuhiro Nakamura, Yuki Miyabe, Nobutaka Mukumoto, Yukinori Matsuo, Akira Sawada, Masaki Kokubo, Takashi Mizowaki, Masahiro Hiraoka
PURPOSE: To develop a four-dimensional (4D) dose calculation system for real-time tumor tracking (RTTT) irradiation by the Vero4DRT. METHODS: First, a 6-MV photon beam delivered by the Vero4DRT was simulated using EGSnrc. A moving phantom position was directly measured by a laser displacement gauge. The pan and tilt angles, monitor units, and the indexing time indicating the phantom position were also extracted from a log file. Next, phase space data at any angle were created from both the log file and particle data under the dynamic multileaf collimator...
February 16, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28211367/high-quality-four-dimensional-cone-beam-ct-reconstruction-using-motion-compensated-total-variation-regularization
#18
Hua Zhang, Jianhua Ma, Zhaoying Bian, Dong Zeng, Qianjin Feng, Wufan Chen
Four dimensional cone-beam computed tomography (4D-CBCT) has great potential clinical value because its ability to describe tumor and organ motion. But the challenge in 4D-CBCT reconstruction is the limited number of projections at each phase, which resulting in the reconstruction full of noise and streak artifacts with the conventional analytical algorithms. To address this problem, in this paper, we propose a motion compensated total variation regularization approach which tries to maximum explore the temporal coherence of the spatial structures among 4D-CBCT phases...
February 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28211303/proposal-of-new-classification-of-femoral-trochanteric-fracture-by-three-dimensional-computed-tomography-and-relationship-to-usual-plain-x-ray-classification
#19
Etsuo Shoda, Shimpei Kitada, Yu Sasaki, Hitoshi Hirase, Takahiro Niikura, Sang Yang Lee, Atsushi Sakurai, Keisuke Oe, Takeharu Sasaki
PURPOSE: Classification of femoral trochanteric fractures is usually based on plain X-ray findings using the Evans, Jensen, or AO/OTA classification. However, complications such as nonunion and cut out of the lag screw or blade are seen even in stable fracture. This may be due to the difficulty of exact diagnosis of fracture pattern in plain X-ray. Computed tomography (CT) may provide more information about the fracture pattern, but such data are scarce. In the present study, it was performed to propose a classification system for femoral trochanteric fractures using three-dimensional CT (3D-CT) and investigate the relationship between this classification and conventional plain X-ray classification...
January 2017: Journal of Orthopaedic Surgery
https://www.readbyqxmd.com/read/28211058/a-feasibility-study-of-a-hybrid-breast-immobilization-system-for-early-breast-cancer-in-proton-beam-therapy
#20
Takeshi Arimura, Takashi Ogino, Takashi Yoshiura, Mitsugi Matsuyama, Naoaki Kondo, Hideki Miyazaki, Akari Sakuragi, Takayuki Ohara, Etsuyo Ogo, Yoshio Hishikawa
PURPOSE: We aimed to develop a new breast-immobilizing system for proton beam therapy (PBT) of early breast cancer (EBC) that would provide the optimum breast shape during the treatment as well as increased fixation reliability by reducing the influence of respiratory movement. METHODS: The breast-immobilizing system (HyBIS; Hybrid Breast-Immobilizing System) consists of a whole body immobilization system (WBIS), position converting device (to change patient position), photo scanning system, breast cup (made using a three-dimensional printer), breast cup fitting apparatus, breast cup holding device (to ensure the breast remains lifted in the supine position), and dedicated stretcher fixed to the WBIS (to carry the patient)...
February 16, 2017: Medical Physics
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