Download or read book Comparison of Cone Beam CT and Conventional CT in Accuracy of Rapid Prototype Models Image Registration written by Gerald T. Grant and published by . This book was released on 2009 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High precision Cone beam CT Guidance of Head and Neck Surgery written by Nathaniel M. Hamming and published by . This book was released on 2009 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern image-guided surgery aids minimally-invasive, high-precision procedures that increase efficacy of treatment. This thesis investigates two research aims to improve precision and integration of intraoperative cone-beam CT (CBCT) imaging in guidance of head and neck (H&N) surgery. First, marker configurations were examined to identify arrangements that minimize target registration error (TRE). Best arrangements minimized the distance between the configuration centroid and surgical target while maximizing marker separation. Configurations of few markers could minimized TRE with more markers providing improved uniformity. Second, an algorithm for automatic registration of image and world reference frames was pursued to streamline integration of CBCT with real-time tracking and provide automatic updates per scan. Markers visible to the tracking and imaging systems are automatically co-localized and registered with equivalent accuracy and superior reproducibility compared to conventional registration. Such work helps the implementation of CBCT in H&N surgery to maximize surgical precision and exploit intraoperative image guidance.

Download or read book Cone Beam Computed Tomography written by Chris C. Shaw and published by Taylor & Francis. This book was released on 2014-02-14 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional computed tomography (CT) techniques employ a narrow array of x-ray detectors and a fan-shaped x-ray beam to rotate around the patient to produce images of thin sections of the patient. Large sections of the body are covered by moving the patient into the rotating x-ray detector and x-ray source gantry. Cone beam CT is an alternative technique using a large area detector and cone-shaped x-ray beam to produce 3D images of a thick section of the body with one full angle (360 degree or 180 degree plus detector coverage) rotation. It finds applications in situations where bulky, conventional CT systems would interfere with clinical procedures or cannot be integrated with the primary treatments or imaging systems. Cone Beam Computed Tomography explores the past, present, and future state of medical x-ray imaging while explaining how cone beam CT, with its superior spatial resolution and compact configuration, is used in clinical applications and animal research. The book: Supplies a detailed introduction to cone beam CT, covering basic principles and applications as well as advanced techniques Explores state-of-the-art research and future developments while examining the fundamental limitations of the technology Addresses issues related to implementation and system characteristics, including image quality, artifacts, radiation dose, and perception Reviews the historical development of medical x-ray imaging, from conventional CT techniques to volumetric 3D imaging Discusses the major components of cone beam CT: image acquisition, reconstruction, processing, and display A reference work for scientists, engineers, students, and imaging professionals, Cone Beam Computed Tomography provides a solid understanding of the theory and implementation of this revolutionary technology.

Download or read book High precision Cone beam CT Guidance of Head and Neck Surgery written by Nathaniel Hamming and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cone Beam CT and 3D imaging written by Pietro Caruso and published by Springer Science & Business Media. This book was released on 2013-09-24 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cone beam computed tomography (CBCT) has become the standard of reference in dental imaging. The distribution of CBCT devices is increasingly wide, and the number of required examinations is constantly growing. In this setting, it is now essential that medical and technical staff receive specific training in the use of CBCT and that technical guidelines for CBCT examinations are established. This clearly structured book on CBCT will be an ideal aid in daily clinical practice. It clearly explains basic CBCT anatomy, examination technique, and the use of 3D reformatting software. A wide range of cases are presented, covering the most frequent and relevant conditions and pathologies, including dental anomalies, inflammatory and degenerative disease, tumors, and implants.

Download or read book 3D Printing for the Radiologist E Book written by Nicole Wake and published by Elsevier Health Sciences. This book was released on 2021-05-27 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive, yet concise, 3D Printing for the Radiologist presents an overview of three-dimensional printing at the point of care. Focusing on opportunities and challenges in radiology practice, this up-to-date reference covers computer-aided design principles, quality assurance, training, and guidance for integrating 3D printing across radiology subspecialties. Practicing and trainee radiologists, surgeons, researchers, and imaging specialists will find this an indispensable resource for furthering their understanding of the current state and future outlooks for 3D printing in clinical medicine. - Covers a wide range of topics, including basic principles of 3D printing, quality assurance, regulatory perspectives, and practical implementation in medical training and practice. - Addresses the challenges associated with 3D printing integration in clinical settings, such as reimbursement, regulatory issues, and training. - Features concise chapters from a team of multidisciplinary chapter authors, including practicing radiologists, researchers, and engineers. - Consolidates today's available information on this timely topic into a single, convenient, resource.

Download or read book Weight Bearing Cone Beam Computed Tomography WBCT in the Foot and Ankle written by Martinus Richter and published by Springer Nature. This book was released on 2019-12-18 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This scientific, technical and clinical guide to Weight Bearing Cone Beam Computed Tomography (WBCT), written by the board of the International WBCT Society, presents all of the relevant content to date on the development, implementation, interpretation and clinical application of WBCT for the foot and ankle. Part One describes the history of the development of, and need for, WBCT as an imaging option and a scientific overview of the procedure. Part Two is an exhaustive scientific background, comprised of 16 landmark studies, describing its advantages for selected foot and ankle injuries and deformities (both congenital and acquired). With this science as context, Part Three includes chapters on the technical aspects and necessary background for WBCT, introduces the different devices, and provides insight into the actual measurement possibilities, including the initial software solutions for automatic measurements. Current clinical applications via case material are illustrated in atlas-like fashion in the next chapter, and a final chapter on future developments explores further applications of WBCT, such as dynamic scans and measurements or hologram-like visualization. The first book publication of its kind on this exciting and developing imaging modality, Weight Bearing Cone Beam Computed Tomography (WBCT) in the Foot and Ankle will be an excellent resource for orthopedic and foot and ankle surgeons, radiologists, and allied medical professionals working in this clinical area.

Download or read book Dose Differences Calculated on Cone beam CT CBCT and Conventional CT an Investicative Study for the Validity of CBCT based Adaptive Radiation Therapy written by Jesse Daniel Tubbs and published by . This book was released on 2010 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quality Assurance Experience for a Ceiling mounted Robotic Cone Beam CT in a Proton Pencil Beam Scanning Environment written by Chia-ho Hua and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Purpose: Our half-gantry, pencil-beam scanning proton therapy system uses a novel ceiling-mounted robotic cone-beam CT (CBCT) for imaging guidance. CBCT is performed at 3 locations including 2 positions offset 27cm and 100cm from the radiation isocenter. Here we share some QA experience over a three-year period. Methods: Two important aspects with offset imaging isocenter QA are: 1) to ensure the accuracy of robotic patient positioning system (PPS), and 2) to ensure imagine isocenter congruence with the radiation isocenter. Daily QA includes output, range, spot position, spot size check, end to end image acquisition and registration, PPS shifts, mechanical and safety checks. Monthly QA includes additional tests for output, spot size, spot position, range, image quality, 6DOF image registration accuracy, Winston-Lutz test for coincidence of radiation versus IGRT. Results:PPS positioning accuracy measured with laser tracker is within +/- 0.5 mm for rotation and translation between each isocenter. Gantry radiation isocenter is within 1.0 mm radius from mechanical isocenter. Three imaging isocenters are within 0.5 mm radius from mechanical isocenter. Imaging-radiation isocenter coincidence are within 1. 3 mm at every 30-degree gantry angle for various energies. CBCT registration uncertainty measured in the end-to-end test is within +/- 0.5 mm and +/- 0.5 degree. Beam characteristics are found to be reliable such as output (within +/- 1%), spot position (+/- 1 mm), spot size FWHM (within 10%), and range (within 1mm). Conclusion: We have instituted QA programs to routinely monitor the system performance for the safe use of the system. Off-isocenter imaging locations present unique perspective for QA development.

Download or read book Evaluation of State of the Art Hardware Architectures for Fast Cone Beam CT Reconstruction written by Holger Scherl and published by Springer Science & Business Media. This book was released on 2011-07-29 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Holger Scherl introduces the reader to the reconstruction problem in computed tomography and its major scientific challenges that range from computational efficiency to the fulfillment of Tuy's sufficiency condition. The assessed hardware architectures include multi- and many-core systems, cell broadband engine architecture, graphics processing units, and field programmable gate arrays.

Download or read book Comparison of Patient Localization Accuracy Between Stereotactic X Ray Based Setup and Cone Beam CT Based Setup on Intensity Modulated Radiation Therapy written by Naoki Hayashi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Comparison of Patient Localization Accuracy Between Stereotactic X-Ray Based Setup and Cone Beam CT Based Setup on Intensity Modulated Radiation Therapy.

Download or read book Computed Tomography written by Thorsten M. Buzug and published by Springer Science & Business Media. This book was released on 2008-05-20 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides an overview of X-ray technology and the historical development of modern CT systems. The main focus of the book is a detailed derivation of reconstruction algorithms in 2D and modern 3D cone-beam systems. A thorough analysis of CT artifacts and a discussion of practical issues such as dose considerations give further insight into current CT systems. Although written mainly for graduate students, practitioners will also benefit from this book.

Download or read book Deformable Registration Techniques for Thoracic CT Images written by Ali Imam Abidi and published by Springer. This book was released on 2020-05-30 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on novel approaches for thoracic computed tomography (CT) image registration and determination of respiratory motion models in a range of patient scenarios. It discusses the use of image registration processes to remove the inconsistencies between medical images acquired using different devices. In the context of comparative research and medical analysis, these methods are of immense value in image registration procedures, not just for thoracic CT images, but for all types of medical images in multiple modalities, and also in establishing a mean respiration motion model. Combined with advanced techniques, the methods proposed have the potential to advance the field of computer vision and help improve existing methods. The book is a valuable resource for those in the scientific community involved in modeling respiratory motion for a large number of people.

Download or read book Registration of Whole body CT Images Using Patient specific Biomechanical Models written by Mao Li and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable and accurate radiographic image registration that quantitatively compares the similarities or differences between the source and target images is critical for application of medical imaging in cancer diagnosis, treatment assessment and therapy planning. Before such quantitative comparisons can be done, it necessitates aligning the source and target images that typically acquired for different postures, or at different times of the patient (i.e. patient's stature/organ geometry are often affected by the therapy and disease progression). A large number of medical image registration methods solely relying on image processing technologies have been successfully developed over the years. However, many of them have been proven effective for a single organ or a selected segment. Problems that involve large differences between the source and target images caused by motion of articulated bones/skeletons and deformations of soft body organs/tissues, such as whole-body Computed Tomography (CT), still remain a challenge. Therefore, biomechanical models, in which predicting the deformation filed of body organs/tissues is treated as a computational problem of solid mechanics, have been introduced in past decades.The deformation field predicted by the patient-specific biomechanical models is used to warp source images to target configuration. This needs to compute position/location of all voxels within the discretised geometry from the nodal displacements and coordinates through interpolation within the element using element shape functions. The number of voxels in a typical whole-body CT image dataset is over 3?107, therefore, an efficient numerical inverse isoparametric mapping algorithm to calculate the local coordinates of arbitrary points within the 8-noded hexahedral finite element has been developed.Fully non-linear (i.e. accounting for both geometric and material non-linearity) finite element (FE) analysis has been historically used for computation of soft organ/tissue deformation. To facilitate rapid generation of patient-specific finite element models, time-consuming image segmentation that divides the problem domain into non-overlapping constituents with different material properties is abandoned in this thesis. Instead, the Fuzzy C-Means (FCM) algorithm is used for tissue classification and assigning material properties automatically at integration points of the computation grid direct form the CT images. Despite the 4-noded tetrahedral element is the most popular choice for computational biomechanics, the 8-noded under-integrated (with one Gauss point) hexahedral elements are used for spatial discretisation of the 3-D whole-body geometries as they do not exhibit volumetric locking. Furthermore, the 8-noded hexahedral meshes tend to offer better computational efficiency than tetrahedral meshes (for the same characteristic size of an element, less hexahedrons than tetrahedrons are needed to mesh a given volume).Generation of hexahedral meshes for the 3-D whole-body geometries requires time-consuming manual correction even with the advanced software packages. To eliminate tedious mesh generation, the meshless (also known as mesh-free) method is used for predicting deformations of body organs/tissues. The meshless method utilizes an unstructured cloud of points for spatial discretization and, therefore, is much less demanding when building computational grids than the finite element discretization. The patient-specific meshless models are solved by a suite of meshless algorithms (Meshless Total Lagrangian Explicit Dynamics MTLED). The deformations of body organs/tissues computed using non-linear meshless models are verified against the results computed using the non-linear finite element models.The registration accuracy of whole-body CT images using the patient-specific biomechanical models is qualitatively and quantitatively evaluated. For quantitative evaluation, I use edge-based Hausdorff distance (HD) to quantify the spatial differences between the registered (i.e. source images warped using the deformations predicted by biomechanical models) and target images. The results confirm that accurate whole-body CT image registration can be achieved using a patient-specific non-linear biomechanical model (i.e. finite element models and meshless models) constructed with fuzzy tissue classification for material property assignment.

Download or read book Comparison of Patient Localization Accuracy Between Stereotactic X Ray Based Setup and Cone Beam CT Based Setup on Intensity Modulated Radiation Therapy written by Naoki Hayashi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Board Cone Beam CT for Treatment Planning in Image Guided Radiotherapy written by Fouad Abdulaziz Abolaban and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Movement of tumours between or during radiotherapy treatment fractions poses a risk to surrounding healthy tissues and potentially lowers the treatment dose to the intended area. To increase the efficacy of radiotherapy, radiation oncologists utilise image-guided radiotherapy (IGRT) to enhance the delivery of radiation to cancerous tumours. Concern about concomitant radiation doses and poor quality images have previously limited the use of such technology when developing treatment plans for adaptive radiotherapy. Recent improvements to the On-board Imager (OBI; Varian version 1.4) including expansion of the number of acquiring modes from four to six, have rejuvenated efforts to use Cone Beam Computed Tomography (CBCT) with OBI as a radiotherapy treatment planning tool. Aim: This research aimed to investigate the possibility of using the new version of the Varian On-Board CBCT imager Vl.4, for adaptive radiotherapy. This work has led to the development of a methodology on how to initiate and implement CBCT scans for - - - - - -- -. -- - -- .- -- the purpose of increasing the accuracy of radiotherapy treatments using adaptive radiotherapy. Methods: The adaptation of radiotherapy plans using CBCT scan images involved three stages. CBCT concommitant doses were determined in the first stage by measuring the dose received by three types of phantom; the RANDO anthropomorphic phantom, the computer-imaging reference system phantom (CIRS) and cylindrical water phantoms of varying diameter. Two- and three-dimensional simulations were also obtained for CBCT using EXCEL, and Monte Carlo codes (BEAMnrc and DOSXYZnrc). The manufacturer's schematic diagram of the head was used to simulate a detailed CBCT dose simulation with the effect of beam output and bow-tie filter included as dose-modifiers. Based on these dose measurements, relationships between CBCT concomitant dose and patient size were found. In addition, estimations of secondary induced cancer were modelled based on these doses. In the second stage, CBCT scan calibrations were conducted. The relationship IV Abstract between the Hounsfield Unit (HU) and electron density (ED) of CBCT scans were described mathematically for each CIRS-062A phantom configuration. Later, these CBCT HU-to-ED calibrations were benchmarked against the CT RU-to-ED relationship of GE lightspeed CT employed in treatment planning. Finally, in the third stage, the obtained HU-to-ED calibrations were applied to treatment plans calculated on CIRS and RANDO phantoms using single-beam and IMRT configurations. Dose calculations derived from the OBI CBCT were compared with those from the GE Lightspeed CT. Results:Using a female RANDO phantom, doses were lowered by factors of36, 8,22 and 16, at the eyes, oesophagus, thyroid and brain, respectively, when using the new version ofVarian CBCT vl.4. In both the standard dose head mode and pelvis mode, the concomitant dose at all positions decreases as the phantom size increases. The concomitant dose measured on the smallest cylindrical water phantoms (10cm in diameter) resulted in a theoretical risk of secondary skin cancer of 0.005% in the standard dose mode and 0.05% in the pelvis mode, assuming a 30-fraction course of -- -treatmentwith CBCT images acquired on a daily basis. Importantly, these-doses are - approximately 10 times greater than those measured for the largest phantom. The risk of secondary cancer for this phantom size at the oesophagus, thyroid, and brain sites are 0.0443, 0.0106 and 0.0439 % respectively for 30 daily images of head and neck treatment. Dose calculations on both the CIRS and RANDO phantoms showed that for the single beam treatment, only 1 % difference in the mean dose values are delivered to the majority of insertions when using the original CT or CBCT images and respective calibration curves. The only exception was for dense bone, which exhibited a 2% difference. For the IMRT treatment plan results showed that when the CT scan image is used the mean doses were less than 1.1 %. Conclusion: CBCT doses from the OBI version 1.4 are significantly lower than doses from version 1.3, making it possible to use CBCT to assist with adaptive radiotherapy on a daily basis, without a significantly increased secondary cancer risk. This technology is a useful tool to aid patient positioning for radiotherapy and to allow v Abstract VI daily adaptive IGRT. Radiation dose varies significantly with both patient size and tumour position in relation to scanning mode. It is therefore recommended that patient-specific imaging protocols be considered, especially with regard to paediatric patients who can be expected to receive a higher dose. The single beam and the WRT comparisons showed that the CBCT images and calibration curves can be used in treatment planning.

Download or read book Adaptive Radiation Therapy written by X. Allen Li and published by CRC Press. This book was released on 2011-01-27 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern medical imaging and radiation therapy technologies are so complex and computer driven that it is difficult for physicians and technologists to know exactly what is happening at the point-of-care. Medical physicists responsible for filling this gap in knowledge must stay abreast of the latest advances at the intersection of medical imaging an