X-ray computed tomography (CT) is instrumental in medicine, industry and homeland security, which depicts internal structures of an object from its shadows projected in a fan-beam or cone-beam from an x-ray source along a appropriate trajectory. We published the first paper on spiral conebeam CT in 1991 to solve the long object problem. Now, spiral conebeam scanning has been widely used in modern CT scanners, in which conebeam rotation and table translation are simultaneously performed, and spiral cone-beam CT remains a major area in CT research and development ...

In recent years the development of cone-beam reconstruction algorithms has been an active research area in x-ray computed tomography (CT), and significant progress has been made in the advancement of algorithms. Theoretically exact and computationally efficient analytical algorithms can be found in the literature. However, in single photon emission computed tomography (SPECT), published cone-beam reconstruction algorithms are either approximate or involve iterative methods. The SPECT reconstruction problem is more complicated due to degradations in the imaging detection process, one of which is the effect of attenuation of gamma ray photons. Attenuation should be compensated for to obtain quantitative results. In this paper, an analytical reconstruction algorithm for uniformly attenuated cone-beam projection data is presented for SPECT imaging. The algorithm adopts the DBH method, a procedure consisting of differentiation and backprojection followed by a finite inverse cosh-weighted Hilbert transform.

Recently, several computed tomography (CT) machines with multirow detectors have been introduced on the market. Although the projections are obtained from a cone beam rather than a fan beam, multislice reconstruction algorithms in contemporary machines are firmly rooted in two-dimensional (2D) reconstruction of planar objects. Short-scan algorithms are dominating and these are preferably classified according to how redundant data are handled, using parallel rebinning, complementary rebinning, or Parker weighting. In the long run, truly 3D cone-beam algorithms are likely to take over, however. It has proved to be quite a challenge to design an algorithm that is both practical and exact under the constraints set by helical source path geometry. All attempts in this direction are readily seen to be derivatives of Grangeats algorithm. Alternative research efforts have been building on the nonexact algorithm by Feldkamp et al. (J Opt Soc Am 1: 612-619, 1984). These algorithms strive for simplicity ...

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High resolution images are used to track the motion of small arteries under application of a static radial pressure. A Fourier-based method for tracking bo

This project aims to reconstruct the passive flexion motion of the knee based on anatomical data alone, which includes bony anatomy, cartilage geometry and ligament insertion sites geometry.

Most people are familiar with simple surface anatomy of the foot however it is much more complex beneath the surface. Lets explore the bony anatomy of the foot.

Valgus alignment of the knee is defined as a mechanical axis of the leg that passes lateral to the centre of the knee. Varus OA of the knee is more …

Radiosurgical approaches to cancer treatment are showing promise in the treatment of lung, liver, and spinal tumors, according to four leading clinical...

Exact Interior Reconstruction with Cone-Beam CT. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

In the early era of radiotherapy, radiation planning was based on external anatomic landmarks and simple measurements of patient thickness.1 These plans were obviously crude, but the large field size presumably made up for inaccuracies in treatment planning. By the 1960s, fluoroscopic simulators, which emulated treatment machine geometry, were developed commercially, allowing radiation oncologists to design fields based on bony anatomy. Radiation planning was performed in two dimensions following the fluoroscopic simulation, in which plain radiographs were taken in the treatment position. The external contour of the patient was modeled at the isocenter of the field, and relevant internal structures were drawn on the contour by the physician, including the target and critical normal organs. The appropriate location of these structures was determined by their anatomic relationship with bony anatomy. Although the visualization of bony anatomy allowed radiation fields to become more complex, they ...

This 3D printable polar bear skull was generated from CT scan data. This 3D model shows bony anatomy of the skull in exquisite detail, including the maxilla, mandible, teeth and other structures of the skull. The skull has been sectioned in half so that the inner bony anatomy is clearly visible. ...

TY - GEN. T1 - An image-based method for objectively assessing injection moulded plastic quality. AU - Hannemose, Morten. AU - Nielsen, Jannik Boll. AU - Zsíros, László. AU - Aanæs, Henrik. PY - 2017. Y1 - 2017. N2 - In high volume productions based on casting processes, like high-pressure die casting (HPDC) or injection moulding, there is a wide range of variables that affect the end quality of produced parts. These variables include production parameters (temperature, pressure, mixture), and external factors (humidity, temperature, etc.). With this many variables it is a challenge to maintain a stable output quality, wherefore massive amounts of resources are spent on quality assurance (QA) of produced parts. Currently, this QA is done manually through visual inspection. We demonstrate how a multispectral imaging system can be used to automatically rate the quality of a produced part using an autocorrelation and a Fourier-based method. These methods are compared with human rankings and ...

Comparison of cone-beam computed tomography and three-dimensional scanner methods on the basis of observers and the gold standard

The CereTom Clinical X-ray CT scanner in the InVivo Imaging suite at the University of Notre Dame delivers the highest quality non-contrast, angiography, and contrast perfusion scans in a variety of patient locations.

Keynote Addresses -- Rethinking Computer Architecture Research -- Event Servers for Crisis Management -- DIET: Building Problem Solving Environments for the Grid -- The Future Evolution of High-Performance Microprocessors -- Low Power Robust Computing -- Networks and Games -- Plenary Session - Best Papers -- An Incentive Driven Lookup Protocol for Chord-Based Peer-to-Peer (P2P) Networks -- A Novel Battery Aware MAC Protocol for Ad Hoc Wireless Networks -- Session I -Wireless Network Management -- Dynamic Topology Construction in Bluetooth Scatternets -- Efficient Secure Aggregation in Sensor Networks -- Optimal Access Control for an Integrated Voice/Data CDMA System -- Adaptive Load Balancing of Cellular CDMA Systems Considering Non-uniform Traffic Distributions -- An Active Framework for a WLAN Access Point Using Intels IXP1200 Network Processor -- MuSeQoR: Multi-path Failure-Tolerant Security-Aware QoS Routing in Ad Hoc Wireless Networks -- Session II - Compilers and Runtime Systems -- A ...

The purpose of this article is to retrospectively determine the image quality and degree of radiation dose reduction that is clinically acceptable for CT-guided renal tumor cryoablation. A total of 15 patients (17 procedures; mean age, 67 years

There are several trends in lung cancer patient management, all leading to an increase in the number of patients being treated with stereotactic body radiothera...

in Astronomy and Astrophysics (2011), 525. Context. The second short run (SRa02) of the CoRoT space mission for asteroseismology was partly devoted to stars belonging to the Mon OB2 association. An intense monitoring has been performed on Plaskett ... [more ▼]. Context. The second short run (SRa02) of the CoRoT space mission for asteroseismology was partly devoted to stars belonging to the Mon OB2 association. An intense monitoring has been performed on Plasketts star (HD 47129) and the unprecedented quality of the light curve allows us to shed new light on this very massive, non-eclipsing binary system. ,BR /, Aims: We particularly aimed at detecting periodic variability that might be associated with pulsations or interactions between both components. We also searched for variations related to the orbital cycle that could help to constrain the inclination and the morphology of the binary system. ,BR /, Methods: We applied an iterative Fourier-based prewhitening and a multiperiodic fitting ...

Immunotherapy targeting the PD-1/PD-L1 pathway had previously been shown to be efficacious in the treatment of patients with metastatic head and neck squamous

TY - JOUR. T1 - MO‐B‐351‐02. T2 - Dual‐Energy CT: Dual‐KV Techniques and Clinical Applications. AU - McCollough, Cynthia H. PY - 2008/1/1. Y1 - 2008/1/1. N2 - In CT imaging, materials having different chemical compositions can be represented by the same, or very similar, CT numbers, making the differentiation and classification of different types of tissues extremely challenging. In dual energy CT, an additional attenuation measurement is obtained at a second energy, allowing the differentiation of the two materials. Previously implemented in the 1980s, dual‐kV techniques are again available on clinical CT systems, accomplished with either slow or fast tube potential switching or dual‐source methods. The fundamental principles of dual‐kV techniques and their relative strengths and weaknesses will be reviewed. Clinical applications of dual‐kV CT imaging will be described, including: 1) automatic removal of bony anatomy, including calcified plaque, from a CT data set; 2) ...

学位の種類: 博士（医学）. 報告番号: 甲第4061号. 学位記番号: 新大院博（医）甲第650号. 学位授与年月日: 平成27年9月24日

TY - JOUR. T1 - Adjuvant stereotactic body radiotherapy for resected pancreatic adenocarcinoma with close or positive margins. AU - Rwigema, Jean Claude M.. AU - Heron, Dwight E.. AU - Parikh, Simul D.. AU - Zeh, Herbert J.. AU - Moser, James A.. AU - Bahary, Nathan. AU - Ashby, Karlotta. AU - Burton, Steven A.. N1 - Copyright: Copyright 2012 Elsevier B.V., All rights reserved.. PY - 2012/3. Y1 - 2012/3. N2 - Purpose: The aim of this study was to evaluate the role of stereotactic body radiotherapy (SBRT) as adjuvant therapy for resected pancreatic adenocarcinoma with close or positive margins. Methods: Between September 2006 and January 2010, 24 patients were treated with adjuvant SBRT following surgical resection. Eight (33.3%) patients had close margins of 1-2.5 mm to the retroperitoneal, vascular structures, and periduodenal adipose tissue. Sixteen (66.7%) patients had positive margins at retroperitoneal margin and vascular structures. Twenty-three patients received 24 Gy (20-24 Gy) in one ...

The utility of positron emission tomography/computed tomography in target delineation for stereotactic body radiotherapy for liver metastasis from primary gastric cancer: an illustrative case report and literature review

Dose distribution of stereotactic body radiotherapy (SBRT) for a tumor in superior (A, B) and in inferior lobe (E, F). Prescribed doses were both 48 Gy in four

(2015) Jereczek-Fossa et al. Reports of Practical Oncology and Radiotherapy. Objectives: To review the available data about stereotactic body-radiotherapy (SBRT) for oligometastatic lymph node cancer recurrence. Methods: The inclusion criteria for this study were as follows: Medline search for th...

2. Make sure you regularly update yourself on your knowledge of bony anatomy and of neuroanatomy, and understand the potential accessory innervation of the structures you operate on.. For concise information on medical conditions and drugs that have implications for dental treatment, please visit our Oasis Help site.. Finally, we would like to promote the concept of you (or a designate in your dental office) regularly taking an Oasis Moment - it just takes a moment to stay up to date with content on Oasis, and it just takes a moment to share content (ideas/photos/suggestions for resources and news) through Oasis. In the spirit of the Oasis Moment, I have two requests of you.. 1. Can you please share any stress reduction protocol you employ in your dental office?. 2. Can you please do as I have done with Dr. Isen and use your iPhone to capture concise, good quality, short videos that would be of interest to professional colleagues across Canada and that we could share through Oasis?. Please ...

The new high-resolution CT system with low radiation dose Radiation dose reduction of up to 83% in cardiac scans and 50% across the rest of the body Improved resolution--33% higher than the conventional ...

Recent studies have reported improvement of outcomes (progression-free survival, overall survival, and prolongation of androgen deprivation treatment-free survival) with stereotactic body radiotherapy (SBRT) in non-small cell lung cancer and prostate cancer.

TY - JOUR. T1 - Radiation Dose Reduction from Radionuclide Myocardial Perfusion Imaging. AU - Marcassa, Claudio. AU - Zoccarato, Orazio. PY - 2016/1/1. Y1 - 2016/1/1. N2 - Due to a tremendous increase in imaging usage in the last decades, in particular of myocardial perfusion imaging with radionuclide tracers, significant concerns have been recently raised on the possible harmful effect of the exposure of patients and health care operators to ionizing radiation. Recent estimates indicate that cardiac imaging procedures account for almost 40 % of the cumulative dose for imaging procedures. Thus, pertinent scientific associations published recommendations directed to limit patients exposure. The key points in the dose optimization process, including appropriate patients selection, stress test and study protocol, new processing software and new hardware, are described.. AB - Due to a tremendous increase in imaging usage in the last decades, in particular of myocardial perfusion imaging with ...

Trofimov A, Nguyen PL, Efstathiou JA, Wang Y, Lu HM, Engelsman M, Merrick S, Cheng CW, Wong JR, Zietman AL. Interfractional variations in the setup of pelvic bony anatomy and soft tissue, and their implications on the delivery of proton therapy for localized prostate cancer. Int J Radiat Oncol Biol Phys. 2011 Jul 1; 80 (3): 928-37 ...

Aim: To evaluate and characterize the musculotendinous pathologies of shoulder joint using ultrasound (USG) and magnetic resonance imaging (MRI). Background and Objectives: The glenohumeral joint, being the most mobile and unstable of all the joints, is often prone to injuries. To compensate for its unstable bony anatomy, the shoulder is protected anteriorly, posteriorly, and superiorly by a capsule and tendons that form the rotator cuff. Sonography is often considered the first-line imaging modality in the assessment of cuff as well as in nonrotator cuff disorders. MRI is of value in cases of extensive abnormality that is often incompletely characterized by the initial sonographic examination, as in case of sonographically inaccessible areas. However, musculoskeletal imaging is truly a multimodality approach and in order to identify and characterize the lesion, a combination of modalities should be used. Materials and Methods: A prospective study was carried out on 75 patients in the Department ...

Bharat SampathiJohn A. Scolaro Bony Anatomy The tibial plateau is the proximal weight-bearing surface of the tibia and articulates with the medial and lateral distal femoral condyles. The intercondylar eminence is positioned between the medial and lateral plateau and does not articulate directly with the femur. The lateral plateau is convex in both the coronal…

Cone-beam (CB) computed tomography (CT) is widely used in the field of medical imaging for guidance. Inspired by Betrams directional interpolation (BDI) methods, directional sinogram interpolation (DSI) was implemented to generate more CB projection

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TY - JOUR. T1 - Stereotactic body radiotherapy (SBRT) for oligometastatic lung tumors from colorectal cancer and other primary cancers in comparison with primary lung cancer. AU - Takeda, Atsuya. AU - Kunieda, Etsuo. AU - Ohashi, Toshio. AU - Aoki, Yousuke. AU - Koike, Naoyoshi. AU - Takeda, Toshiaki. PY - 2011/11. Y1 - 2011/11. N2 - Purpose: To analyze local control of oligometastatic lung tumors (OLTs) compared with that of primary lung cancer after stereotactic body radiotherapy (SBRT). Materials and methods: Retrospective record review of patients with OLTs who received SBRT with 50 Gy in 5 fractions. Local control rates (LCRs), toxicities, and factors of prognostic significance were assessed. Results: Twenty-one colorectal OLTs, 23 OLTs from other origins, and 188 primary lung cancers were included. Multivariate analysis revealed only tumor origin was prognostically significant (p , 0.05). The 1-year/2-year LCRs in colorectal OLTs and OLTs from other origins were 80%/72% and 94%/94%, ...

TY - JOUR. T1 - Analysis of suitable prescribed isodose line fitting to planning target volume in stereotactic body radiotherapy using dynamic conformal multiple arc therapy. AU - Oku, Yohei. AU - Takeda, Atsuya. AU - Kunieda, Etsuo. AU - Sudo, Yasunobu. AU - Oooka, Yoshikazu. AU - Aoki, Yousuke. AU - Shimouchi, Yoshiaki. AU - Nishina, Ryohei. AU - Nomura, Kazuhiro. AU - Sugiura, Madoka. AU - Ohashi, Toshio. N1 - Copyright: Copyright 2012 Elsevier B.V., All rights reserved.. PY - 2012/1. Y1 - 2012/1. N2 - Purpose: To assess the most suitable value of a relative prescribed dose in clinical treatment plans of stereotactic body radiotherapy (SBRT) using dynamic conformal multiple arc therapy to treat lung tumors. Methods and Materials: We retrospectively generated alternative SBRT plans for typical examples of 8 patients who had been treated with SBRT for a lung tumor with a prescribed dose of 50 Gy in 5 fractions. The prescribed dose had been defined as 80% of the maximal dose in the planning ...

TY - JOUR. T1 - Phase i dose-escalation study of stereotactic body radiotherapy in patients with hepatic metastases. AU - Rule, William. AU - Timmerman, Robert. AU - Tong, Liyue. AU - Abdulrahman, Ramzi. AU - Meyer, Jeffrey. AU - Boike, Thomas. AU - Schwarz, Roderich E.. AU - Weatherall, Paul. AU - Cho, L. Chinsoo. PY - 2011/4/1. Y1 - 2011/4/1. N2 - Purpose: To identify a tolerable and effective dose for 5- fraction stereotactic body radiotherapy for hepatic metastases. Methods: Patients were enrolled onto three dose-escalation cohorts: 30 Gy in 3 fractions, 50 Gy in 5 fractions, and 60 Gy in 5 fractions. Eligible patients had one to five hepatic metastases, ability to spare a critical hepatic volume (volume receiving ,21 Gy) of 700 ml, adequate baseline hepatic function, no concurrent antineoplastic therapy, and a Karnofsky performance score of ≥60. Doselimiting toxicity included treatment-related grade 3 toxicity in the gastrointestinal, hepatobiliary/pancreas, and metabolic/ laboratory ...

Stereotactic Body Radiotherapy (SBRT), is an emerging image-guided radiation method. SBRT is directed to extremely well-defined targets within the body. SBRT will deliver very high doses of radiation precisely to tumor sites within the body with the purpose of improving local control and limiting side effects.

Stereotactic Body Radiotherapy (SBRT) is increasingly used to treat a variety of head and neck tumors as a result of its highly conformal dose distributions and stereotactic spatial accuracy in delivery. Our experience and other previous reports have shown that SBRT is technically feasible, well-tolerated and compares favorably to other alternatives of salvage therapy in the management of patients with recurrent and/or previously irradiated head and neck cancers. Furthermore, it has the advantage of a shorter treatment schedule, greater compliance, and safe delivery in the outpatient setting. This affords an opportunity to introduce SBRT as a definitive treatment in select patients. This review presents an overview of the use of SBRT for managing head and neck tumors by highlighting the existing indications and the expanding role of SBRT in managing these patients.

This review summarizes the evidence of stereotactic body radiotherapy (SBRT) as an alternative to surgery (lobectomy and sublobar resection) for stage I NSCLC. Three randomized trials comparing SBRT and surgery were initiated but all three were stopped early due to poor accrual. As the next level of evidence, results from matched-pair analyses performed in single-institutional (n = 4), multi-institutional (n = 3) and population-based (n = 3) settings are available. There was close agreement between all studies that SBRT is at least equivalent to sublobar resection making it the preferred treatment for a high-risk population. SBRT was equivalent to lobectomy in the endpoints of loco-regional control and cancer-specific survival. Disease-free survival and overall survival were inferior after SBRT compared with lobectomy in one and two studies, respectively, and not significantly different in all other studies. Consequently, for patients without relevant comorbidities, who are accepting the risk of ...

Trial Design - Patients with stage IV non-small cell lung cancer are randomized to nivolumab/ipilimumab plus either sequential or concurrent stereotactic body

Low back pain manifests as isolated, focal pain in the central lower spine. Dysfunction at the lumbar spine can result in pain that extends the full length of the leg. The bony anatomy of the spine houses the spinal cord and neural tissues that connect to the entire lower extremity. Therefore, when we have movement dysfunction or inflammation at the joints of the spine, these neural tissues can become compromised and can be affected anywhere along their course. We often see pain originating from the low back manifest as hip, buttock, thigh, knee, calf, or ankle pain. At PT Solutions, we take a full body approach to discover the origin of dysfunction rather than just treating the symptoms ...

REFERENCES. 1. Farman AG, Scarfe WC. Development of imaging selection criteria and procedures should precede cephalometric assessment with cone-beam computed tomography. Am J Orthod Dentofacial Orthop. 2006;130(2):257-65. [ Links ] 2. Schulze D, Heiland M, Thurmann H, Adam G. Radiation exposure during midfacial imaging using 4- and 16-slice computed tomography, cone-beam computed tomography systems and conventional radiography. Dentomaxillofac Radiol. 2004;33(2):83-6. [ Links ] 3. Silva MA, Wolf U, Heinicke F, Bumann A, Visser H, Hirsch E. Cone-beam computed tomography for routine orthodontic treatment planning: a radiation dose evaluation. Am J Orthod Dentofacial Orthop. 2008;133(5):640.e1-5. [ Links ] 4. Tsiklakis K, Donta C, Gavala S, Karayianni K, Kamenopoulou V, Hourdakis CJ. Dose reduction in maxillofacial imaging using low dose Cone-beam CT. Eur J Radiol. 2005;56(3):413-7. [ Links ] 5. Scarfe W, Farman A. What is cone-beam CT and how does it work? Dent Clin North Am. 2008;52(4):707-30. [ ...

In this section youll find the latest news and information about West Physics, including all of our press releases; relevant news about the medical imaging industry in the U.S. and abroad; and recent regulatory updates that may affect your facility or organization.. ...

Intraoperative cone-beam computed tomography and multi-slice computed tomography in temporal bone imaging for surgical treatment.: CBCT provides comparable imag

TY - JOUR. T1 - SU‐GG‐T‐537. T2 - Dosimetric Effect of Residual Tumor Motion in Phase and Amplitude‐Based Gated Lung Stereotactic Body Radiotherapy. AU - Zhao, B.. AU - Yang, Y.. AU - Heron, D.. AU - Huq, M.. PY - 2010. Y1 - 2010. N2 - Purpose To evaluate dosimetric effect of residual tumor motion in lung Stereotactic Body Radiotherapy(SBRT) with two gating methods using external markers: amplitude‐(AG) and phase‐based(PG). Methods and Materials The 3D tumor motion data were obtained from the treatment logs of 6 lung patients with various target size, each treated with 3 fractions of SBRT using Cyberknife Robotic Radiosurgical System and Synchrony™(Accuray, Sunnyvale CA). Amplitude and phase‐based gating treatments were simulated with a gating window of 5 mm. Planning target volume(PTV) was defined as physician‐contoured clinical target volume(CTV) surrounded by isotropic 5 mm margin. Each patient was prescribed with 60Gy/3fractions prescribed to 80% isodose line which covered ...

Maybe. And maybe not. It depends on a lot of different things: the shape of your hip joint, the orientation of the joint socket; the torsional angle of your thigh bone; the laxity of your ligaments; t...

We present a detailed derivation of the phase-retrieval formula based on the phase-attenuation duality that we recently proposed in previous brief communication. We have incorporated the effects of x-ray source coherence and detector resolution into the phase-retrieval formula as well. Since only a single image is needed for performing the phase retrieval by means of this new approach, we point out the great advantages of this new approach for implementation of phase tomography. We combine our phase-retrieval formula with the Feldkamp-Davis-Kresss (FDK) cone-beam reconstruction algorithm to provide a three-dimensional phase tomography formula for soft tissue objects of relatively small sizes, such as small animals or human breast. For large objects we briefly show how to apply Katsevichs cone-beam reconstruction formula to the helical phase tomography as well.. ©2005 Optical Society of America. Full Article , PDF Article ...

In order to provide an x-ray CT device and a contrast imaging method which are capable of obtaining an image having a favorable contrast effect without re-injecting a contrast medium, when the imaging position will overtake the contrast medium position during imaging using a contrast medium, this x-ray CT device performs the following: determines whether or not the current imaging position will overtake the contrast medium during the main imaging; resets the imaging conditions when the contrast medium will be overtaken, and executes re-imaging using the reset imaging conditions; and when determining that the contrast medium will be overtaken, performs the determination based on differential data between measurement data obtained by non-contrast imaging performed prior to the main imaging, and measurement data obtained by the main imaging. As a result, it is possible to quickly make an overtaking determination, and immediately move on to re-imaging, without needing to reconstruct an image during the