A methodology for 3D image reconstruction from retrospectively gated cone-beam CT projection data has been developed. A mobile x-ray cone-beam device consisting of an isocentric C-arm equipped with a flat panel detector was used to image a moving phantom. Frames for reconstruction were retrospectively selected from complete datasets based on the known rotation of the C-arm and a signal from a respiratory monitor. Different sizes of gating windows were tested. A numerical criterion for blur on the reconstructed image was suggested. The criterion is based on minimization of an Ising energy function, similar to approaches used in image segmentation or restoration. It is shown that this criterion can be used for the determination of the optimal gating window size. Images reconstructed from the retrospectively gated projection sequences using the optimal gating window data showed a significant improvement compared to images reconstructed from the complete projection datasets.
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http://dx.doi.org/10.1088/0031-9155/50/22/004 | DOI Listing |
Med Phys
January 2025
UC Davis Medical Center, Sacramento, California, USA.
PLoS One
August 2024
Department of Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Ave, Nedlands, Western Australia, Australia.
Background: GammaKnife (GK) and CyberKnife (CK) have been the mainstay stereotactic radiosurgery (SRS) solution for multiple brain metastases (MBM) for several years. Recent technological advancement has seen an increase in single-isocentre C-arm linac-based SRS. This systematic review focuses on dosimetric and geometric insights into contemporary MBM SRS and thereby establish if linac-based SRS has matured to match the mainstay SRS delivery systems.
View Article and Find Full Text PDFPhys Med Biol
May 2024
Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing Anzhen Hospital, Capital Medical University, Beijing, People's Republic of China.
Digitally reconstructed radiography (DRR) plays an important role in the registration of intraoperative x-ray and preoperative CT images. However, existing DRR algorithms often neglect the critical isocentric fixed angle irradiation (IFAI) principle in C-arm imaging, resulting in inaccurate simulation of x-ray images. This limitation degrades registration algorithms relying on DRR image libraries or employing DRR images (DRRs) to train neural network models.
View Article and Find Full Text PDFJ Cancer Res Ther
January 2024
Depertment of Physics, GLA University, Mathura, Uttar Pradesh, India.
Purpose: The purpose of this study is to evaluate the dosimetric and treatment delivery characteristics of volumetric modulated arc therapy technique (VMAT)-based craniospinal axis irradiation (CSI) between ring gantry Halcyon (HAL) and C-arm based Novalis Tx (NTx) linear accelerator. Set-up margin and treatment delivery time for both machines were also taken into account.
Materials And Methods: Fifteen patients, 4 females and 11 males treated between March 2019 and February 2022 within the age group 4-56 years simulated in the supine position and were planned for multiple isocentre VMAT technique in ring gantry Halcyon and C-Arm Novalis linear accelerator for 6FFF and 6 MV flatten beam energy.
Arch Orthop Trauma Surg
February 2024
Department of Trauma Hand and Reconstructive Surgery, Ulm University, Albert-Einstein-Allee 23, 89081, Ulm, Germany.
Introduction: Surgical treatment options for acromioclavicular joint separations are varied. Frequently, suspension devices (SD) are inserted for stabilization under arthroscopic view. This study investigates the feasibility and accuracy of three-dimensional (3D) digital-volume-tomography (DVT) C-arm navigated implantation with regard to the general trend toward increasingly minimally invasive procedures.
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