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Sample records for computed tomography applications

  1. Computed Tomography. Evolution, technical principles and applications

    International Nuclear Information System (INIS)

    Calzado, A.; Geleijns, J.

    2010-01-01

    Computed tomography has become one of the most commonly used diagnostic techniques. Since its clinical introduction in 1971, subsequent developments have led to the emergence of new indications in different medical specialties. This paper reviews the evolution of art; essential characteristics of CT scanners are described and different application modalities in diagnosis are reviewed as well. (Author).

  2. Application of protons to computer tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.; Bradbury, J.N.; Cannon, T.M.; Hutson, R.L.; Laubacher, D.B.; Macek, R.; Paciotti, M.A.; Taylor, C.A.

    1977-01-01

    It was demonstrated that the application of protons to computed tomography can result in a significant dose advantage relative to x rays. Thus, at the same dose as is delivered by contemporary commercial x-ray scanners, a proton scanner could produce reconstructions with a factor of 2 or more improvement in density resolution. Whether such an improvement can result in significantly better diagnoses of human disease is an open question which can only be answered by the implementation of a proton scanner in a clinical situation

  3. Nano-Computed Tomography: Technique and Applications.

    Science.gov (United States)

    Kampschulte, M; Langheinirch, A C; Sender, J; Litzlbauer, H D; Althöhn, U; Schwab, J D; Alejandre-Lafont, E; Martels, G; Krombach, G A

    2016-02-01

    Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE (-/-)/LDLR(-/-) double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques. Nano-computed tomography is a high resolution CT-technology for 3D imaging at sub-micrometer resolution. The technical concept bases on a further development of the established ex-vivo-micro-CT technology. By improvement of the spatial resolution, structures at a cellular level become visible (e.g. osteocyte lacunae). © Georg Thieme Verlag KG Stuttgart · New York.

  4. Computed Tomography

    Science.gov (United States)

    Castellano, Isabel; Geleijns, Jacob

    After its clinical introduction in 1973, computed tomography developed from an x-ray modality for axial imaging in neuroradiology into a versatile three dimensional imaging modality for a wide range of applications in for example oncology, vascular radiology, cardiology, traumatology and even in interventional radiology. Computed tomography is applied for diagnosis, follow-up studies and screening of healthy subpopulations with specific risk factors. This chapter provides a general introduction in computed tomography, covering a short history of computed tomography, technology, image quality, dosimetry, room shielding, quality control and quality criteria.

  5. An industrial application of computer assisted tomography

    International Nuclear Information System (INIS)

    Tonner, P.D.; Tosello, G.

    1984-10-01

    Computer assisted tomography (CAT) scanning is a nondestructive testing technique used to obtain quantitatively accurate mappings of the distribution of linear attenuation coefficients inside an object. To demonstrate the potential of the technique for accurately locating defects in three dimensions a sectioned 5 cm gate valve, with a shrink cavity made visible by the sectioning, was tomographically imaged using a Co-60 source. The tomographic images revealed a larger cavity below the sectioned surface. The position of this cavity was located with an in-plane and axial precision of approximately +- 1 mm. The volume of the cavity was estimated to be approximately 40 mm 3

  6. Compressive sampling in computed tomography: Method and application

    International Nuclear Information System (INIS)

    Hu, Zhanli; Liang, Dong; Xia, Dan; Zheng, Hairong

    2014-01-01

    Since Donoho and Candes et al. published their groundbreaking work on compressive sampling or compressive sensing (CS), CS theory has attracted a lot of attention and become a hot topic, especially in biomedical imaging. Specifically, some CS based methods have been developed to enable accurate reconstruction from sparse data in computed tomography (CT) imaging. In this paper, we will review the progress in CS based CT from aspects of three fundamental requirements of CS: sparse representation, incoherent sampling and reconstruction algorithm. In addition, some potential applications of compressive sampling in CT are introduced

  7. Applications of industrial computed tomography at Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Kruger, R.P.; Morris, R.A.; Wecksung, G.W.

    1980-01-01

    A research and development program was begun three years ago at the Los Alamos Scientific Laboratory (LASL) to study nonmedical applications of computed tomography. This program had several goals. The first goal was to develop the necessary reconstruction algorithms to accurately reconstruct cross sections of nonmedical industrial objects. The second goal was to be able to perform extensive tomographic simulations to determine the efficacy of tomographic reconstruction with a variety of hardware configurations. The final goal was to construct an inexpensive industrial prototype scanner with a high degree of design flexibility. The implementation of these program goals is described

  8. Applications of cone beam computed tomography for a prosthodontist

    Directory of Open Access Journals (Sweden)

    George Puthenpurayil John

    2016-01-01

    Full Text Available Cone beam computed tomography (CBCT is a medical imaging technique of X-ray computed tomography where the X-rays are divergent, forming a cone. CBCT systems have been designed for imaging hard tissues of the maxillofacial region. The increasing availability of this technology provides the dental clinician with an imaging modality capable of providing a three-dimensional representation of the maxillofacial skeleton with minimal distortion. This article is intended to elaborate and enunciate on the various applications and benefits of CBCT, in the realm of maxillofacial prosthodontics, over and beyond its obvious benefits in the rehabilitation of patients with implants. With the onus of meticulous reconstruction of near ideal occlusion resting on the prosthodontist, CBCT provides a unique imaging option, which can be a boon in various aspects of prosthodontic practice – from imaging of the temporomandibular joint for accurate movement simulation, to template assisted maxillofacial reconstruction or even over denture therapy. CBCT could play a crucial role in lessening the burden of a hectic prosthodontic routine for the clinician and critically contribute to accurate and effective treatment for the patient. Apart from the authors' clinical experiences shared here, a web-based search for relevant articles in this specific area of interest was also conducted. The selected articles were critically reviewed and the data acquired were systematically compiled.

  9. Application and development of Industrial Computed Tomography in China

    International Nuclear Information System (INIS)

    Kong Fangeng; Xian Wu

    1996-01-01

    Compared with traditional perspective radiography, ICT (Industrial Computed Tomography) is able to acquire tomography image without the disadvantages of image overlapping and blurring that exist in traditional perspective radiography. By acquiring the 2D tomography image of the object at different stage as many as needed, it is possible to achieve 3D tomography image. In China, the first Γ-ray ICT equipment was born at Chongqing University in May 1993. For this equipment, 60 Co radiation source with 1 Ci and 30 Ci was used, and spatial resolution is about 0.5mm, and density resolution is about 0.5%, and the diameter of the test object can be 300mm, but the price of the Chinese ICT equipment is only about a half on the same type of ICT equipment producing abroad other than China. Besides Γ-ray ICT, Chinese are engaging in research and develop x-ray ICT to meet foreign and domestic need. (author)

  10. Nonmedical application of computed tomography to power capacitor quality assesment

    International Nuclear Information System (INIS)

    Kruger, R.P.

    1981-01-01

    Present research and development efforts at Los Alamos Scientific Laboratory require the design and use of high-efficiency rapid-discharge energy storage capacitors for laser isotope separation and plasma physics programs. In these applications, capacitors are subjected to electrical, mechanical, thermal, and other environmental stresses. These stresses cause the dielectric constant to change due to gasification from arcing at nonsoldering connections, which produce a chemical reduction of the dielectric material. This effectively limits the lifetime of the capacitor. The programs mentioned above require capacitors with a multikilohertz frequency response at a current of tens of kiloamperes and a voltage of at least 100 kV. The lifetime of such capacitors should exceed 10 10 charge/discharge cycles. Such capacitors do not presently exist. The exploration of new capacitor designs will require the use of both electrical functional tests and tests that show the changes in internal physical structure as the capacitor is repeatedly stressed by the charge/discharge cycle. The integration of electrical and structural tests throughout the life cycle of a candidate capacitor makes it imperative that the structural integrity tests be nondestructive. Computed tomography (CT) makes this integration possible. The work reported here is the result of a pilot project designed to show the potential use of CT for this application. This work includes visualization of material defects using both a layered sequence of conventional tomographic slices and orthogonal multiangular pseudoradiographs generated from these slices

  11. The application of computed tomography in wound ballistics research

    Science.gov (United States)

    Tsiatis, Nick; Moraitis, Konstantinos; Papadodima, Stavroula; Spiliopoulou, Chara; Kelekis, Alexis; Kelesis, Christos; Efstathopoulos, Efstathios; Kordolaimi, Sofia; Ploussi, Agapi

    2015-09-01

    In wound ballistics research there is a relationship between the data that characterize a bullet and the injury resulted after shooting when it perforates the human body. The bullet path in the human body following skin perforation as well as the damaging effect cannot always be predictable as they depend on various factors such as the bullet's characteristics (velocity, distance, type of firearm and so on) and the tissue types that the bullet passes through. The purpose of this presentation is to highlight the contribution of Computed Tomography (CT) in wound ballistics research. Using CT technology and studying virtual “slices” of specific areas on scanned human bodies, allows the evaluation of density and thickness of the skin, the subcutaneous tissue, the muscles, the vital organs and the bones. Density data taken from Hounsfield units can be converted in g/ml by using the appropriate software. By evaluating the results of this study, the anatomy of the human body utilizing ballistic gel will be reproduced in order to simulate the path that a bullet follows. The biophysical analysis in wound ballistics provides another application of CT technology, which is commonly used for diagnostic and therapeutic purposes in various medical disciplines.

  12. Clinical applications of the computed tomography of the thorax

    International Nuclear Information System (INIS)

    Hong, Seong Eun; Kim, Ho Kyun; Kim, Soon Yong

    1980-01-01

    The computed tomography of the thorax has had considerably less impact in patient management than that of head and abdomen, because the convention chest radiography is a much more sensitive and accurate examination than the plain film studies of the head and abdomen. It has progressively been identified that the computed tomography of chest is superior to the conventional radiography in detection of small pulmonary nodules including occult metastatic lesions, in evaluation of character of hilar enlargement, and in staging of known bronchogenic caner. And especially in mediastinum, the computed tomography is supported to the any other conventional radiography in outlining lesions and determining character and extent of lesions. At the department of radiology, Kyung Hee University Hospital , 87 cases of computed tomography of chest were performed with EMI-CT 5005 whole-body scanner from October 1977 to August 1979. The results were as following; 1. The fifty eight cases of considered to be pathologic findings were 23 pleural thickening and/or effusion, 14 bronchogenic carcinoma, 8 inflammatory lesions of lung parenchyme, 6 mediastinal lesions, 3 metastinal lesions, 3 COPD, 1 trauma, respectively. 2. No gravity-dependent change was noted in patients with chronic obstructive pulmonary disease (COPD), which was frequently seen in normal subjects. Diminished numbers of pulmonary vessels was noted in COPD. 3. Small nodules in lung, retrosternal, posterior costophrenic and subpleural regions, which were not found on conventional radiography, can be detected by chest CT. 4. Differentiation of dilated central pulmonary artery from pulmonary mass in enlarged hilum and determination of adjacent mediastinal invasion, manifested by obliterated fat plane, was possible. 5. The cases of mediastinal widening such as paraspinal ilpomatosis, pericardial fat pad, teratoma, and bronchogenic cyst were easily determined by means of measuring the attenuation coefficiencies. 6. Small amount

  13. Application of C-arm computed tomography in cardiology

    International Nuclear Information System (INIS)

    Rieber, J.; Rohkohl, C.; Lauritsch, G.; Rittger, H.; Meissner, O.

    2009-01-01

    C-arm computed tomography is currently being introduced into cardiac imaging and offers the potential for three-dimensional imaging of the cardiac anatomy within the interventional environment. This detailed view is necessary to support complex interventional strategies, such as transcutaneous valve replacement, interventional therapy of atrial fibrillation, implantation of biventricular pacemakers and assessment of myocardial perfusion. Currently, the major limitation of this technology is its insufficient temporal resolution which limits the visualization of fast moving parts of the heart. (orig.) [de

  14. Prior image constrained image reconstruction in emerging computed tomography applications

    Science.gov (United States)

    Brunner, Stephen T.

    Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  16. Application of computer assisted tomography in gynaecological oncology

    International Nuclear Information System (INIS)

    Pickel, H.; Schreithofer, H.; Sager, W.D.; Graz Univ.

    1980-01-01

    The non invasive radiologic technique of computed tomography has been employed since 1978 at the University Women's Clinic and Radiologic Clinic, Graz. One hundred and fourty six examinations of the pelvis, abdomen and chest were performed on 63 oncologic patients. The method was employed for the preoperative detection and measurement of the size of benign and malignant neoplasms; in tumour staging and assessment of therapeutic response. The results suggest that CT might be the best method for the assessment of response to cytotoxic therapy of ovarian cancer. (orig.) [de

  17. Computed tomography in the detection of pulmonary metastases. Improvement by application of spiral technology

    International Nuclear Information System (INIS)

    Kauczor, H.U.; Hansen, M.; Schweden, F.; Strunk, H.; Mildenberger, P.; Thelen, M.

    1994-01-01

    Computed tomography is the imaging modality of choice for detection or exclusion of pulmonary metastases. In most cases these are spheric, multiple, bilateral, and located in the peripheral areas of the middle and lower fields of the lungs. Differential diagnosis of solitary pulmonary nodules is difficult. Evaluating whether they are malignant or benign is insufficient despite the application of multiple CT criteria. Spiral computed tomography acquiring an imaging volume in a breathhold has led to significant improvement in the sensitivity of detecting pulmonary nodules. Imaging protocols are presented, and the influence of the different parameters is discussed. Although not all pulmonary metastases may be detected with spiral computed tomography, it is the most important examination when considering pulmonary metastasectomy. Computed tomography is the imaging modality of choice when monitoring pulmonary metastases during systemic therapeutic regimens by measuring all nodules or 'indicator lesions'. (orig.) [de

  18. Applicability study of x-ray computed tomography technique

    International Nuclear Information System (INIS)

    Tanai, Kenji

    2003-03-01

    Several experiments on the study of high level radioactive waste disposal indirectly measured various physical quantity in the closed test vessel by various sensor. This measurement technique on closed-system cause limit of understanding of mechanisms. Therefore, new observation technique by nondestructive technique such a X-ray computed tomography is necessary for HLW disposal study. In this work, the objective of this study are as follows; (1) to clarify the relationship between dry density of bentonite and CT number, (2) to observed infiltration behaviour of liquid in bentonite specimen using X-ray CT (3) to observed gas migration behaviour in bentonite specimen using X-ray CT. The major conclusions obtained in this study are as follows; (1) CT number of X-ray increases linearly with degree of saturation and density of bentonite specimen. (2) Infiltration behaviour of liquid in bentonite specimen can be observed by X-ray CT. (3) Gas permeability of bentonite with a dry density of 1.6 Mg/m3 is approximately 6 x 10 -20 m 2 . And, this result was almost the same with the other experimental results. But, significant difference of breakthrough phenomena was observed between this test and other experiments results. In visualization study of gas migration through bentonite, gas migration behavior through bentonite was not observed by X-ray CT. (author)

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography ( ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT of the sinuses is primarily used ...

  1. The application of preoperative computed tomography angiogram for hemispherectomy

    Directory of Open Access Journals (Sweden)

    Jiqing Qiu

    2017-10-01

    Full Text Available Hemispherectomy is an established neurosurgical procedure for unilateral refractory epilepsy . Even though the surgical approach has evolved greatly, prevention of catastrophic intraoperative bleeding is a challenge. It is important that surgeons know the abnormal blood vessel before surgery. Herein, we report our experience with two patients in whom computed tomographic angiography (CTA was used in the preoperative evaluation for hemispherectomy. CTA allowed for precise anatomical delineation of the hemispheric vascular abnormalities. Preoperative CTA showed that the specific cerebral arteries and their branches ipsilateral to the lesion were slender. Elaborate preoperative planning for the surgical approach helped prevent catastrophic intraoperative bleeding. Favorable outcomes were achieved in both children. CTA appears to confer a considerable advantage in the preoperative vascular and anatomical delineation in patients scheduled for hemispherectomy. To our knowledge, this is the first report about the application of CTA for hemispherectomy preoperative planning.

  2. Computed tomography

    International Nuclear Information System (INIS)

    Boyd, D.P.

    1989-01-01

    This paper reports on computed tomographic (CT) scanning which has improved computer-assisted imaging modalities for radiologic diagnosis. The advantage of this modality is its ability to image thin cross-sectional planes of the body, thus uncovering density information in three dimensions without tissue superposition problems. Because this enables vastly superior imaging of soft tissues in the brain and body, CT scanning was immediately successful and continues to grow in importance as improvements are made in speed, resolution, and cost efficiency. CT scanners are used for general purposes, and the more advanced machines are generally preferred in large hospitals, where volume and variety of usage justifies the cost. For imaging in the abdomen, a scanner with a rapid speed is preferred because peristalsis, involuntary motion of the diaphram, and even cardiac motion are present and can significantly degrade image quality. When contrast media is used in imaging to demonstrate scanner, immediate review of images, and multiformat hardcopy production. A second console is reserved for the radiologist to read images and perform the several types of image analysis that are available. Since CT images contain quantitative information in terms of density values and contours of organs, quantitation of volumes, areas, and masses is possible. This is accomplished with region-of- interest methods, which involve the electronic outlining of the selected region of the television display monitor with a trackball-controlled cursor. In addition, various image- processing options, such as edge enhancement (for viewing fine details of edges) or smoothing filters (for enhancing the detectability of low-contrast lesions) are useful tools

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Perfusion of the Head CT Angiography (CTA) Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography ( ...

  4. Computed Tomography. Evolution, technical principles and applications; Tomografia computarizada. Evolucion, principios tecnicos y aplicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Calzado, A.; Geleijns, J.

    2010-07-01

    Computed tomography has become one of the most commonly used diagnostic techniques. Since its clinical introduction in 1971, subsequent developments have led to the emergence of new indications in different medical specialties. This paper reviews the evolution of art; essential characteristics of CT scanners are described and different application modalities in diagnosis are reviewed as well. (Author).

  5. The application of computed tomography and magnetic resonance imaging at diagnostics of the human maxillofacial system

    Science.gov (United States)

    Nikitin, V.; Karavaeva, E.; Cherepennikov, Yu; Miloichikova, I.

    2016-06-01

    The application of computed tomography and magnetic resonance imaging has entered into wide practice at diagnosis of the maxillofacial system. Computed tomography allows us to obtain information about only bone structures. Magnetic resonance imaging gives information about bone and soft tissue structures of the maxillofacial system. The sagittal and coronal projections should make for complete diagnosis of the temporomandibular joint, because the articular disc is very mobile structure. We suggest that the temporomandibular joint can influences the internal carotid artery at medial displacement of the articular disc. As a result of analysis of the literature and our own studies concluded that changes TMJ affect the internal carotid artery.

  6. Clinical applications of cone beam computed tomography in endodontics: A comprehensive review.

    Science.gov (United States)

    Cohenca, Nestor; Shemesh, Hagay

    2015-09-01

    The use of cone beam computed tomography (CBCT) in endodontics has been extensively reported in the literature. Compared with the traditional spiral computed tomography, limited field of view (FOV) CBCT results in a fraction of the effective absorbed dose of radiation. The purpose of this manuscript is to review the application and advantages associated with advanced endodontic problems and complications, while reducing radiation exposure during complex endodontic procedures. The benefits of the added diagnostic information provided by intraoperative CBCT images in select cases justify the risk associated with the limited level of radiation exposure.

  7. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.

    1986-01-01

    Computed tomography is regarded by many as a complicated union of sophisticated x-ray equipment and computer technology. This book overcomes these complexities. The rigid technicalities of the machinery and the clinical aspects of computed tomography are discussed including the preparation of patients, both physically and mentally, for scanning. Furthermore, the author also explains how to set up and run a computed tomography department, including advice on how the room should be designed

  8. Application of MCNP{trademark} to computed tomography in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Brockhoff, R.C. [KSU (United States); Estes, G.P.; Hills, C.R. [Mason and Hanger (United States); Demarco, J.J.; Solberg, T.D. [California Univ., Los Angeles, CA (United States)

    1996-03-01

    The MCNP{trademark} code has been used to simulate CT scans of the MIRD human phantom. In addition. an actual CT scan of a patient was used to create an MCNP geometry, and this geometry was computationally ``CT scanned`` using MCNP to reconstruct CT images. The results show that MCNP can be used to model the human body based on data obtained from CT scans and to simulate CT scans that are based on these or other models.

  9. Application of computed tomography in Wegener's granulomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, S.; Tani, K.; Kato, K. (Yokohama City Univ. (Japan). Faculty of Medicine)

    1982-06-01

    Computed tomographic (CT) findings in four patiemts with Wegener's granulomatosis were investigated. The diagnosis of Wegener's granulomatosis was made by clinical symptoms and the histological examination of biopsied materials from the nasal mucosa, bronchus and kidney. CT findings in three patients were compatible with the clinical and laboratory manifestations of Wegener's granulomatosis. In one case, CT showed a widening of the nasal cavity, bone destruction of the ethmoid and maxillary sinus. These results suggest that CT studies are very effective to evaluate the extent of Wegener's granulomatosis and its therapeutic effect.

  10. Free and open-source software application for the evaluation of coronary computed tomography angiography images.

    Science.gov (United States)

    Hadlich, Marcelo Souza; Oliveira, Gláucia Maria Moraes; Feijóo, Raúl A; Azevedo, Clerio F; Tura, Bernardo Rangel; Ziemer, Paulo Gustavo Portela; Blanco, Pablo Javier; Pina, Gustavo; Meira, Márcio; Souza e Silva, Nelson Albuquerque de

    2012-10-01

    The standardization of images used in Medicine in 1993 was performed using the DICOM (Digital Imaging and Communications in Medicine) standard. Several tests use this standard and it is increasingly necessary to design software applications capable of handling this type of image; however, these software applications are not usually free and open-source, and this fact hinders their adjustment to most diverse interests. To develop and validate a free and open-source software application capable of handling DICOM coronary computed tomography angiography images. We developed and tested the ImageLab software in the evaluation of 100 tests randomly selected from a database. We carried out 600 tests divided between two observers using ImageLab and another software sold with Philips Brilliance computed tomography appliances in the evaluation of coronary lesions and plaques around the left main coronary artery (LMCA) and the anterior descending artery (ADA). To evaluate intraobserver, interobserver and intersoftware agreements, we used simple and kappa statistics agreements. The agreements observed between software applications were generally classified as substantial or almost perfect in most comparisons. The ImageLab software agreed with the Philips software in the evaluation of coronary computed tomography angiography tests, especially in patients without lesions, with lesions 70% in the ADA was lower, but this is also observed when the anatomical reference standard is used.

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... are the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed ... nasal cavity by small openings. top of page What are some common uses of the procedure? CT ...

  12. Development of a Simple Image Processing Application that Makes Abdominopelvic Tumor Visible on Positron Emission Tomography/Computed Tomography Image.

    Science.gov (United States)

    Pandey, Anil Kumar; Saroha, Kartik; Sharma, Param Dev; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

    2017-01-01

    In this study, we have developed a simple image processing application in MATLAB that uses suprathreshold stochastic resonance (SSR) and helps the user to visualize abdominopelvic tumor on the exported prediuretic positron emission tomography/computed tomography (PET/CT) images. A brainstorming session was conducted for requirement analysis for the program. It was decided that program should load the screen captured PET/CT images and then produces output images in a window with a slider control that should enable the user to view the best image that visualizes the tumor, if present. The program was implemented on personal computer using Microsoft Windows and MATLAB R2013b. The program has option for the user to select the input image. For the selected image, it displays output images generated using SSR in a separate window having a slider control. The slider control enables the user to view images and select one which seems to provide the best visualization of the area(s) of interest. The developed application enables the user to select, process, and view output images in the process of utilizing SSR to detect the presence of abdominopelvic tumor on prediuretic PET/CT image.

  13. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  14. Computer tomography in otolaryngology

    Energy Technology Data Exchange (ETDEWEB)

    Gradzki, J. (Akademia Medyczna, Poznan (Poland))

    1981-01-01

    The principles of design and the action of computer tomography which was applied also for the diagnosis of nose, ear and throat diseases are discussed. Computer tomography makes possible visualization of the structures of the nose, nasal sinuses and facial skeleton in transverse and eoronal planes. The method enables an accurate evaluation of the position and size of neoplasms in these regions and differentiation of inflammatory exudates against malignant masses. In otology computer tomography is used particularly in the diagnosis of pontocerebellar angle tumours and otogenic brain abscesses. Computer tomography of the larynx and pharynx provides new diagnostic data owing to the possibility of obtaining transverse sections and visualization of cartilage. Computer tomograms of some cases are presented.

  15. Application of spectral computed tomography in diagnosis of liver and gallbladder diseases

    Directory of Open Access Journals (Sweden)

    LI Bolong

    2017-03-01

    Full Text Available Spectral computed tomography (CT is a perfect combination of diamond probe and strong computer processing technology and a technological revolution of traditional CT. This article reviews the application of spectral CT in the diagnosis of liver and gallbladder diseases. It summarizes the application value of monochromatic spectral CT imaging, spectral curve, material separation and quantitation, and effective atomic number in the diagnosis and differentiation of liver and gallbladder diseases and analyze the advantages of energy spectrum in identification of small lesions, low dose, and judgment of homology. It is pointed out that the application of spectral CT can be further explored in the aspects of early identification, differentiation, and prognosis of tumors.

  16. Computed Tomography (CT) - Spine

    Science.gov (United States)

    ... the removal of fluid from a localized infection ( abscess ). In patients with narrowing ( stenosis ) of the spine ... Survey Images × Image Gallery Computed Tomography (CT or CAT scan) equipment View full size with caption Do ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... of a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ... Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  2. Applications of Dual-Energy Computed Tomography for Artifact Reduction in the Head, Neck, and Spine.

    Science.gov (United States)

    Liao, Eric; Srinivasan, Ashok

    2017-08-01

    Conventional computed tomography (CT) uses a polychromatic energy beam to offer superb anatomic detail of the head and spine. However, technical challenges remain that can degrade the diagnostic image quality of these examinations. Dual-energy CT analyzes the changes in attenuation of soft tissues at different energy levels, from which different reconstructions can be made to yield the optimal contrast-to-noise ratio, reduce beam-hardening artifact, or evaluate tissue composition. In this article, selective applications of the dual energy CT technique are discussed, highlighting a powerful tool in the diagnostic CT evaluation of the head, neck, and spine. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Positron emission computed tomography

    International Nuclear Information System (INIS)

    Grover, M.; Schelbert, H.R.

    1985-01-01

    Regional mycardial blood flow and substrate metabolism can be non-invasively evaluated and quantified with positron emission computed tomography (Positron-CT). Tracers of exogenous glucose utilization and fatty acid metabolism are available and have been extensively tested. Specific tracer kinetic models have been developed or are being tested so that glucose and fatty acid metabolism can be measured quantitatively by Positron-CT. Tracers of amino acid and oxygen metabolism are utilized in Positron-CT studies of the brain and development of such tracers for cardiac studies are in progress. Methods to quantify regional myocardial blood flow are also being developed. Previous studies have demonstrated the ability of Positron-/CT to document myocardial infarction. Experimental and clinical studies have begun to identify metabolic markers of reversibly ischemic myocardium. The potential of Positron-CT to reliably detect potentially salvageable myocardium and, hence, to identify appropriate therapeutic interventions is one of the most exciting applications of the technique

  4. Endodontic applications of cone beam computed tomography: case series and literature review

    Directory of Open Access Journals (Sweden)

    Francesc Abella

    2015-11-01

    Full Text Available Cone beam computed tomography (CBCT is a relatively new method that produces three-dimensional (3D information of the maxillofacial skeleton, including the teeth and their surrounding tissue, with a lower effective radiation dose than traditional CT scans. Specific endodontic applications for CBCT are being identified as the use of this technology becomes more common. CBCT has great potential to become a valuable tool for diagnosing and managing endodontic problems, as well as for assessing root fractures, apical periodontitis, resorptions, perforations, root canal anatomy and the nature of the alveolar bone topography around teeth. This article aims to review cone beam technology and its advantages over CT scans and conventional radiography, to illustrate current and future clinical applications in endodontic practice, and to highlight areas of further research of CBCT in endodontics. Specific case examples illustrate how treatment planning has changed with the images obtained with CBCT technology compared with only periapical radiography.

  5. Application of three-dimensional computed tomography in craniofacial clinical practice and research.

    Science.gov (United States)

    Anderson, P J; Yong, R; Surman, T L; Rajion, Z A; Ranjitkar, S

    2014-06-01

    Following the invention of the first computed tomography (CT) scanner in the early 1970s, many innovations in three-dimensional (3D) diagnostic imaging technology have occurred, leading to a wide range of applications in craniofacial clinical practice and research. Three-dimensional image analysis provides superior and more detailed information compared with conventional plain two-dimensional (2D) radiography, with the added benefit of 3D printing for preoperative treatment planning and regenerative therapy. Current state-of-the-art multidetector CT (MDCT), also known as medical CT, has an important role in the diagnosis and management of craniofacial injuries and pathology. Three-dimensional cone beam CT (CBCT), pioneered in the 1990s, is gaining increasing popularity in dental and craniofacial clinical practice because of its faster image acquisition at a lower radiation dose, but sound guidelines are needed to ensure its optimal clinical use. Recent innovations in micro-computed tomography (micro-CT) have revolutionized craniofacial biology research by enabling higher resolution scanning of teeth beyond the capabilities of MDCT and CBCT, presenting new prospects for translational clinical research. Even after four decades of refinement, CT technology continues to advance and broaden the horizons of craniofacial clinical practice and phenomics research. © 2014 Australian Dental Association.

  6. Positron Emission Tomography - Computed Tomography (PET/CT)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Positron Emission Tomography - Computed Tomography (PET/CT) Positron emission tomography (PET) ... Emission TomographyComputed Tomography (PET/CT)? What is Positron Emission TomographyComputed Tomography (PET/CT) Scanning? Positron emission tomography, ...

  7. Intraoperative computed tomography.

    Science.gov (United States)

    Tonn, J C; Schichor, C; Schnell, O; Zausinger, S; Uhl, E; Morhard, D; Reiser, M

    2011-01-01

    Intraoperative computed tomography (iCT) has gained increasing impact among modern neurosurgical techniques. Multislice CT with a sliding gantry in the OR provides excellent diagnostic image quality in the visualization of vascular lesions as well as bony structures including skull base and spine. Due to short acquisition times and a high spatial and temporal resolution, various modalities such as iCT-angiography, iCT-cerebral perfusion and the integration of intraoperative navigation with automatic re-registration after scanning can be performed. This allows a variety of applications, e.g. intraoperative angiography, intraoperative cerebral perfusion studies, update of cerebral and spinal navigation, stereotactic procedures as well as resection control in tumour surgery. Its versatility promotes its use in a multidisciplinary setting. Radiation exposure is comparable to standard CT systems outside the OR. For neurosurgical purposes, however, new hardware components (e.g. a radiolucent headholder system) had to be developed. Having a different range of applications compared to intraoperative MRI, it is an attractive modality for intraoperative imaging being comparatively easy to install and cost efficient.

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  12. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.J.

    1986-01-01

    This book is directed towards giving radiographers an introduction to and basic knowledge of computerized tomography. The technical section discusses gantries and x-ray production, computer and disc drive image display, storage, artefacts quality assurance and design of departments. The clinical section includes patient preparation, radiotherapy planning, and interpretation of images from various areas of the anatomy. (U.K.)

  13. Computed tomography system

    International Nuclear Information System (INIS)

    Lambert, T.W.; Blake, J.E.

    1981-01-01

    This invention relates to computed tomography and is particularly concerned with determining the CT numbers of zones of interest in an image displayed on a cathode ray tube which zones lie in the so-called level or center of the gray scale window. (author)

  14. An introduction to emission computed tomography

    International Nuclear Information System (INIS)

    Williams, E.D.

    1985-01-01

    This report includes salient features of the theory and an examination of practical considerations for someone who is using or introducing tomography, selecting equipment for it or wishing to develop a clinical application. Emphasis is on gamma camera tomography. The subject is dealt with under the following headings: emission computed and gamma camera tomography and the relationship to other medical imaging techniques, the tomographic reconstruction technique theory, rotating gamma camera tomography, attenuation correction and quantitative reconstruction, other single photon tomographic techniques, positron tomography, image display, clinical application of single photon and positron tomography, and commercial systems for SPECT. Substantial bibliography. (U.K.)

  15. Quantitative cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, M.; Dueber, C.; Wolff, P.; Erbel, R.; Hoffmann, T.

    1985-06-01

    The scope and limitations of quantitative cardiac CT have been evaluated in a series of experimental and clinical studies. The left ventricular muscle mass was estimated by computed tomography in 19 dogs (using volumetric methods, measurements in two axes and planes and reference volume). There was good correlation with anatomical findings. The enddiastolic volume of the left ventricle was estimated in 22 patients with cardiomyopathies; using angiography as a reference, CT led to systematic under-estimation. It is also shown that ECG-triggered magnetic resonance tomography results in improved visualisation and may be expected to improve measurements of cardiac morphology.

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  17. Children's (Pediatric) CT (Computed Tomography)

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  18. Correction of Motion Artifacts From Shuttle Mode Computed Tomography Acquisitions for Body Perfusion Imaging Applications.

    Science.gov (United States)

    Ghosh, Payel; Chandler, Adam G; Altinmakas, Emre; Rong, John; Ng, Chaan S

    2016-01-01

    The aim of this study was to investigate the feasibility of shuttle-mode computed tomography (CT) technology for body perfusion applications by quantitatively assessing and correcting motion artifacts. Noncontrast shuttle-mode CT scans (10 phases, 2 nonoverlapping bed locations) were acquired from 4 patients on a GE 750HD CT scanner. Shuttling effects were quantified using Euclidean distances (between-phase and between-bed locations) of corresponding fiducial points on the shuttle and reference phase scans (prior to shuttle mode). Motion correction with nonrigid registration was evaluated using sum-of-squares differences and distances between centers of segmented volumes of interest on shuttle and references images. Fiducial point analysis showed an average shuttling motion of 0.85 ± 1.05 mm (between-bed) and 1.18 ± 1.46 mm (between-phase), respectively. The volume-of-interest analysis of the nonrigid registration results showed improved sum-of-squares differences from 2950 to 597, between-bed distance from 1.64 to 1.20 mm, and between-phase distance from 2.64 to 1.33 mm, respectively, averaged over all cases. Shuttling effects introduced during shuttle-mode CT acquisitions can be computationally corrected for body perfusion applications.

  19. Nano-computed tomography. Technique and applications; Nanocomputertomografie. Technik und Applikationen

    Energy Technology Data Exchange (ETDEWEB)

    Kampschulte, M.; Sender, J.; Litzlbauer, H.D.; Althoehn, U.; Schwab, J.D.; Alejandre-Lafont, E.; Martels, G.; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Diagnostic and Interventional Radiology; Langheinirch, A.C. [BG Trauma Hospital Frankfurt/Main (Germany). Dept. of Diagnostic and Interventional Radiology

    2016-02-15

    Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE{sub (-/-)}/LDLR{sub (-/-)} double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques.

  20. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Kelman, A.L.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. The tracks are supported on rollers which carry the substantial weight. Explicit engineering details are presented. (U.K.)

  1. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Kelman, A.L.; Peterson, T.E.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. The tracks are supported on rollers which carry the substantial weight. Explicit engineering details are presented especially of the ball bearing races used in the rotation. (U.K.)

  2. Improvement of Portable Computed Tomography System for On-field Applications

    International Nuclear Information System (INIS)

    Sukrod, K.; Khoonkamjorn, P.; Tippayakul, C.

    2014-01-01

    In 2010, Thailand Institute of Nuclear Technology (TINT) received a portable Computed Tomography (CT) system from IAEA as part of the Regional Cooperative Agreement (RCA) program. This portable CT system has been used as the prototype for development of portable CT system intended for industrial applications since then. This paper discusses the improvements in the attempt to utilize the CT system for on-field applications. The system is foreseen to visualize the amount of agarwood in the live tree trunk. The experiments adopting Am-241 as the radiation source were conducted. The Am-241 source was selected since it emits low energy gamma which should better distinguish small density differences of wood types. Test specimens made of timbers with different densities were prepared and used in the experiments. The cross sectional views of the test specimens were obtained from the CT system using different scanning parameters. It is found from the experiments that the results are promising as the picture can clearly differentiate wood types according to their densities. Also, the optimum scanning parameters were determined from the experiments. The results from this work encourage the research team to advance into the next phase which is to experiment with the real tree on the field.

  3. Application of continuous-wave terahertz computed tomography for the analysis of chicken bone structure

    Science.gov (United States)

    Li, Bin; Wang, Dayong; Rong, Lu; Zhai, Changchao; Wang, Yunxin; Zhao, Jie

    2018-02-01

    Terahertz (THz) radiation is able to penetrate many different types of nonpolar and nonmetallic materials without the damaging effects of x-rays. THz technology can be combined with computed tomography (CT) to form THz CT, which is an effective imaging method that is used to visualize the internal structure of a three-dimensional sample as cross-sectional images. Here, we reported an application of THz as the radiation source in CT imaging by replacing the x-rays. In this method, the sample cross section is scanned in all translation and rotation directions. Then, the projection data are reconstructed using a tomographic reconstruction algorithm. Two-dimensional (2-D) cross-sectional images of the chicken ulna were obtained through the continuous-wave (CW) THz CT system. Given by the difference of the THz absorption of different substances, the compact bone and spongy bone inside the chicken ulna are structurally distinguishable in the 2-D cross-sectional images. Using the filtered back projection algorithm, we reconstructed the projection data of the chicken ulna at different projection angle intervals and found that the artifacts and noise in the images are strikingly increased when the projection angle intervals become larger, reflected by the blurred boundary of the compact bone. The quality and fidelity of the 2-D cross-sectional images could be substantially improved by reducing the projection angle intervals. Our experimental data demonstrated a feasible application of the CW THz CT system in biological imaging.

  4. Multislice computed tomography coronary angiography

    NARCIS (Netherlands)

    F. Cademartiri (Filippo)

    2005-01-01

    markdownabstract__Abstract__ Computed Tomography (CT) imaging is also known as "CAT scanning" (Computed Axial Tomography). Tomography is from the Greek word "tomos" meaning "slice" or "section" and "graphia" meaning "describing". CT was invented in 1972 by British engineer Godfrey Hounsfield

  5. Inter-laboratory comparison of medical computed tomography (CT) scanners for industrial applications in the slaughterhouses

    DEFF Research Database (Denmark)

    Christensen, Lars Bager; Angel, Jais Andreas Breusch

    2013-01-01

    Using computed tomography (CT) in the calibration of online grading equipment has been demonstrated to be beneficial over the last years by several institutions using medical CT scanners. The difference in makes and models calls for a standardized (and calibrated) method to be able to quantify di...

  6. Computed tomography device

    International Nuclear Information System (INIS)

    Ohhashi, A.

    1985-01-01

    A computed tomography device comprising a subtraction unit which obtains differential data strings representing the difference between each time-serial projection data string of a group of projection data strings corresponding to a prospective reconstruction image generated by projection data strings acquired by a data acquisition system, a convolution unit which convolves each time-serial projection data string of the group of projection data strings corresponding to the prospective reconstruction image, and a back-projection unit which back-projects the convolved data strings

  7. Development of proton computed tomography detectors for applications in hadron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bashkirov, Vladimir A., E-mail: vbashkirov@llu.edu [Loma Linda University, 11175 Campus Street, Loma Linda 92354 (United States); Johnson, Robert P.; Sadrozinski, Hartmut F.-W. [University of California, Santa Cruz, 1156 High Street, Santa Cruz 95064 (United States); Schulte, Reinhard W. [Loma Linda University, 11175 Campus Street, Loma Linda 92354 (United States)

    2016-02-11

    Radiation therapy with protons and heavier ions is an attractive form of cancer treatment that could enhance local control and survival of cancers that are currently difficult to cure and lead to less side effects due to sparing of normal tissues. However, particle therapy faces a significant technical challenge because one cannot accurately predict the particle range in the patient using data provided by existing imaging technologies. Proton computed tomography (pCT) is an emerging imaging modality capable of improving the accuracy of range prediction. In this paper, we describe the successive pCT scanners designed and built by our group with the goal to support particle therapy treatment planning and image guidance by reconstructing an accurate 3D map of the stopping power relative to water in patient tissues. The pCT scanners we have built to date consist of silicon telescopes, which track the proton before and after the object to be reconstructed, and an energy or range detector, which measures the residual energy and/or range of the protons used to evaluate the water equivalent path length (WEPL) of each proton in the object. An overview of a decade-long evolution of the conceptual design of pCT scanners and their calibration is given. Results of scanner performance tests are presented, which demonstrate that the latest pCT scanner approaches readiness for clinical applications in hadron therapy.

  8. Mesenteric panniculitis: computed tomography aspects

    International Nuclear Information System (INIS)

    Moreira, Luiza Beatriz Melo; Alves, Jose Ricardo Duarte; Marchiori, Edson; Pinheiro, Ricardo Andrade; Melo, Alessandro Severo Alves de; Noro, Fabio

    2001-01-01

    Mesenteric panniculitis is an inflammatory process that represents the second stage of a rare progressive disease involving the adipose tissue of the mesentery. Imaging methods used in the diagnosis of mesenteric panniculitis include barium studies, ultrasonography, computed tomography and magnetic resonance imaging. Computed tomography is important for both, diagnosis and evaluation of the extension of the disease and treatment monitoring. Computed tomography findings may vary according to the stage of the disease and the amount of inflammatory material or fibrosis. There is also good correlation between the computed tomography and anatomical pathology findings. The authors studied 10 patients with mesenteric panniculitis submitted to computed tomography. Magnetic resonance imaging was also performed in one patient. In all patients, computed tomography revealed a heterogeneous mass in the mesentery with density of fat, interspersed with areas of soft tissue density and dilated vessels. (author)

  9. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Kelman, A.L.; O'Dell, W.R.; Brook, R.F.; Hein, P.W.; Brandt, R.T.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. A failsafe, solenoid brake is described which can lock the shaft against rotation. The gantry also contains a hoist mechanism which aids maintenance of the heavy X-ray tube and/or detector arrays. Explicit engineering details are presented. (U.K.)

  10. Iterative Reconstruction for Cardiopulmonary Computed Tomography

    NARCIS (Netherlands)

    Willemink, M.J.

    2015-01-01

    Introduction The number of computed tomography (CT) examinations has increased rapidly since CT became commercially available. This resulted in growing concerns regarding the risk of malignancies induced by application of medical ionizing radiation. Therefore, radiation dose reduction strategies

  11. Reduced-dose C-arm computed tomography applications at a pediatric institution

    Energy Technology Data Exchange (ETDEWEB)

    Acord, Michael; Shellikeri, Sphoorti; Vatsky, Seth; Srinivasan, Abhay; Krishnamurthy, Ganesh; Keller, Marc S.; Cahill, Anne Marie [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2017-12-15

    Reduced-dose C-arm computed tomography (CT) uses flat-panel detectors to acquire real-time 3-D images in the interventional radiology suite to assist with anatomical localization and procedure planning. To describe dose-reduction techniques for C-arm CT at a pediatric institution and to provide guidance for implementation. We conducted a 5-year retrospective study on procedures using an institution-specific reduced-dose protocol: 5 or 8 s Dyna Rotation, 248/396 projection images/acquisition and 0.1-0.17 μGy/projection dose at the detector with 0.3/0.6/0.9-mm copper (Cu) filtration. We categorized cases by procedure type and average patient age and calculated C-arm CT and total dose area product (DAP). Two hundred twenty-two C-arm CT-guided procedures were performed with a dose-reduction protocol. The most common procedures were temporomandibular and sacroiliac joint injections (48.6%) and sclerotherapy (34.2%). C-arm CT was utilized in cases of difficult percutaneous access in less common applications such as cecostomy and gastrostomy placement, foreign body retrieval and thoracentesis. C-arm CT accounted for between 9.9% and 80.7% of the total procedural DAP. Dose-reducing techniques can preserve image quality for intervention while reducing radiation exposure to the child. This technology has multiple applications within pediatric interventional radiology and can be considered as an adjunctive imaging tool in a variety of procedures, particularly when percutaneous access is challenging despite routine fluoroscopic or ultrasound guidance. (orig.)

  12. Design and application of the MARK IV scanning system for radionuclide computed tomography of the brain

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Hoffman, E.J.; Phelps, M.E.; Ricci, A.; Reivich, M.

    1976-01-01

    The MARK IV radioisotope scanning system was built to provide fast and accurate radionuclide computed tomography (RCT). It is designed primarily for detecting commonly available radioactive labels such as /sup 99m/Tc, but it is also adapted to detecting positron emitters such as 18 F. The system has interlaced convergent collimation in a 4-sided arrangement of 32-independent detectors which continuously rotate as a unit, detecting, processing, and displaying the reconstructed data while the study progresses

  13. Application of positron emission tomography-computed tomography in the diagnosis of pulmonary ground-glass nodules.

    Science.gov (United States)

    Hu, Lili; Pan, Yuanwei; Zhou, Zhigang; Gao, Jianbo

    2017-11-01

    The aim of the present study was to investigate the value of positron emission tomography-computed tomography (PET-CT) using 18 F-fluorodeoxyglucose in the clinical diagnosis of pulmonary ground-glass nodule. In total, 54 patients with pulmonary GGN that were identified by PET-CT examination were selected and confirmed by pathology and clinical diagnosis in hospital between April 2014 and April 2015. The association between PET-CT findings and pathology, and the value of PET-CT were then evaluated. In the 54 patients, solitary pulmonary GGN with a nodule diameter of between 0.6 and 2.0 cm were detected. Amongst them, the PET-CT examination of 42 patients revealed hyper metabolic nodules, and were all mixed GGN type nodules with a diameter >1 cm. The PET-CT examination of the remaining 12 patients demonstrated no evidence of metabolic abnormalities and the nodules in these patients were pure or mixed GGN with a diameter <1 cm (except 2 cases with a diameter ≥1 cm). Furthermore, the diagnoses for all patients were pathologically confirmed by CT-guided needle biopsy or thoracoscopic surgical resection. Amongst them, there were 41 cases of lung adenocarcinoma, 4 cases of fungal infection, 7 cases of inflammation and 2 cases of adenomatoid hyperplasia. Additionally, PET-CT has a lower detection rate for smaller GGN exhibits no clear advantage for pure GGN, but has a higher detection rate for larger GGN. In conclusion, to a certain extent, PET-CT makes up for the shortcomings of traditional imaging and has some clinical value for the diagnosis of GGN.

  14. Proton computed tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1978-01-01

    The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible

  15. Computed tomography of choledocholithiasis

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey, R.B.; Federle, M.P.; Laing, F.C.; Wall, S.; Rego, J.; Moss, A.A.

    1983-06-01

    Computed tomography (CT) correctly diagnosed common bile duct stones in 19 (90%) of 21 surgically proven cases. CT demonstrated calculi in all 13 patients with calcium bilirubinate common duct stones and six of eight patients with predominantly cholesterol stones. There were two false-negative diagnoses in patients with cholesterol calculi scanned at 1 cm intervals. Cholesterol stones are nearly isodense with bile and may be difficult to visualize in the common duct by routine scanning techniques. There are three suggestive CT features of cholesterol common duct calculi: (1) abrupt termination of the distal common bile duct without an obstructing mass, (2) a faint rim of increased density along the peripheral margin of a low-density calculus, and (3) mottled areas of increased density centrally within a calculus elevating its CT number above values for normal bile. Modification of scanning technique to obtain high-resolution images of the extrahepatic biliary tree is stressed to optimize visualization of the above findings.

  16. Computed tomography apparatus

    International Nuclear Information System (INIS)

    Palermo, A.; Zupancic, A.

    1981-01-01

    A computed tomography (CT) scanner apparatus including improved arrangement for transferring high voltage electrical energy between a stationary gantry and a rotating assembly is described. The assembly carries the X-ray source and has an opening defining an aperture to receive a part of a patient. A first axis about which the assembly rotates, passes through the aperture. The apparatus includes a number of slip rings which are used for effecting the transfer of the electrical energy. Respective portions of the gantry and rotating assembly define a cavity which contains an insulating di-electric fluid in which the slip rings are immersed. The apparatus is of compact design and, further, the rotating assembly and the slip rings can be tilted about a second axis which intersects the first axis. (author)

  17. A new cone-beam computed tomography system for dental applications with innovative 3D software

    Energy Technology Data Exchange (ETDEWEB)

    Pasini, Alessandro; Bianconi, D.; Rossi, A. [University of Bologna, Department of Physics, Bologna (Italy); NECTAR Imaging srl Imola (Italy); Casali, F. [University of Bologna, Department of Physics, Bologna (Italy); Bontempi, M. [CEFLA Dental Group Imola (Italy)

    2007-02-15

    Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70-100 kVp and 1-4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4'' and 6'') and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10-15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1-1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market. (orig.)

  18. Emission computed tomography

    International Nuclear Information System (INIS)

    Phelps, M.E.

    1977-01-01

    Although there are many common aspects to x-ray transmission and radionuclide emission (ECT) computerized tomography, there are added difficulties and a number of particular factors which form the basis of ECT. The relationship between the physical factors, system design, methodologic approach and assumptions of ECT is discussed. The instrumentation design and application strategies in ECT at this time are diverse and in a rapid stage of development. The approaches are divided into two major categories of Single Photon Counting (SPC) employing scanner and camera concepts with radionuclides of 99 /sup m/Tc, 201 Tl, 123 I etc., and Annihilation Coincidence Detection (ACD) of positron-emitting radionuclides. Six systems in the former and ten systems in the latter category, with examples of typical studies, illustrate the different approaches

  19. [Application of cone-beam computed tomography in the treatment of impacted maxillary teeth].

    Science.gov (United States)

    Wang, Sun; Feng, Xi-ping; Cao, Hui-zhen

    2011-08-01

    To investigate the treatment of impacted maxillary teeth with localization via cone-beam computed tomography (CBCT). Eleven cases with impacted maxillary teeth on X-ray examination were selected from 2009 to 2010. The impacted maxillary teeth were scanned by CBCT.The three-dimensional images of impacted maxillary teeth were obtained by multiplanar reconstructions (MPR) to determine the location of impacted teeth. CBCT and MPR can demonstrate the morphology and location and growing state of the impacted maxillary teeth. CBCT and MPR are the most accurate and effective methods to localize the impacted maxillary teeth.

  20. Inter-laboratory comparison of medical computed tomography (CT) scanners for industrial applications in the slaughterhouses

    DEFF Research Database (Denmark)

    Christensen, Lars Bager; Angel, Jais Andreas Breusch

    2013-01-01

    Using computed tomography (CT) in the calibration of online grading equipment has been demonstrated to be beneficial over the last years by several institutions using medical CT scanners. The difference in makes and models calls for a standardized (and calibrated) method to be able to quantify......, conventionally recognized to be challenging to medical CT scanners. The web based classification software PigClassWeb has been demonstrated to be a convenient way of handling and comparing CT data in a transparent way, across regions and over time. The phantom set may be used to compare regional differences...

  1. Application of the iris filter for automatic detection of pulmonary nodules on computed tomography images.

    Science.gov (United States)

    Suárez-Cuenca, Jorge Juan; Tahoces, Pablo G; Souto, Miguel; Lado, María J; Remy-Jardin, Martine; Remy, Jacques; Vidal, Juan José

    2009-10-01

    We have developed a computer-aided diagnosis (CAD) system to detect pulmonary nodules on thin-slice helical computed tomography (CT) images. We have also investigated the capability of an iris filter to discriminate between nodules and false-positive findings. Suspicious regions were characterized with features based on the iris filter output, gray level and morphological features, extracted from the CT images. Functions calculated by linear discriminant analysis (LDA) were used to reduce the number of false-positives. The system was evaluated on CT scans containing 77 pulmonary nodules. The system was trained and evaluated using two completely independent data sets. Results for a test set, evaluated with free-response receiver operating characteristic (FROC) analysis, yielded a sensitivity of 80% at 7.7 false-positives per scan.

  2. LOCATE: an application of computed tomography in radiation therapy treatment planning with emphasis on tumor localization

    International Nuclear Information System (INIS)

    Griffin, B.R.; Shuman, W.P.; Luk, K.H.; Tong, D.

    1984-01-01

    Computed tomography can provide precise information for radiation therapy treatment planning. However, inaccuracies in radiation field design may occur when the radiation oncologist attempts to tranfer information about tumor location from the transverse plane of the CT scan to the longitudinal plane of the simulation film. This report describes a new computer program, LOCATE, which addresses this problem. The program uses operator generated information from the cross sectional CT images to draw an outline of tumor on AP and lateral longitudinal scanned projection radiographs. The resultant images are useful because they are in the same plane as radiographs obtained on a therapy simulator. The impact of LOCATE on radiation treatment planning for 26 patients is discussed along with several cases in which LOCATE was particularly helpful

  3. Computed tomography intravenous cholangiography

    International Nuclear Information System (INIS)

    Nascimento, S.; Murray, W.; Wilson, P.

    1997-01-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors)

  4. Computed tomography intravenous cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, S.; Murray, W.; Wilson, P. [Pittwater Radiology, Dee Why, NSW, (Australia)

    1997-08-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors). 11 refs., 6 figs.

  5. A dictionary learning approach with overlap for the low dose computed tomography reconstruction and its vectorial application to differential phase tomography.

    Directory of Open Access Journals (Sweden)

    Alessandro Mirone

    Full Text Available X-ray based Phase-Contrast Imaging (PCI techniques have been demonstrated to enhance the visualization of soft tissues in comparison to conventional imaging methods. Nevertheless the delivered dose as reported in the literature of biomedical PCI applications often equals or exceeds the limits prescribed in clinical diagnostics. The optimization of new computed tomography strategies which include the development and implementation of advanced image reconstruction procedures is thus a key aspect. In this scenario, we implemented a dictionary learning method with a new form of convex functional. This functional contains in addition to the usual sparsity inducing and fidelity terms, a new term which forces similarity between overlapping patches in the superimposed regions. The functional depends on two free regularization parameters: a coefficient multiplying the sparsity-inducing L1 norm of the patch basis functions coefficients, and a coefficient multiplying the L2 norm of the differences between patches in the overlapping regions. The solution is found by applying the iterative proximal gradient descent method with FISTA acceleration. The gradient is computed by calculating projection of the solution and its error backprojection at each iterative step. We study the quality of the solution, as a function of the regularization parameters and noise, on synthetic data for which the solution is a-priori known. We apply the method on experimental data in the case of Differential Phase Tomography. For this case we use an original approach which consists in using vectorial patches, each patch having two components: one per each gradient component. The resulting algorithm, implemented in the European Synchrotron Radiation Facility tomography reconstruction code PyHST, has proven to be efficient and well-adapted to strongly reduce the required dose and the number of projections in medical tomography.

  6. Application of X-ray Computed Tomography to Cultural Heritage diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Morigi, M.P.; Casali, F.; Bettuzzi, M.; Brancaccio, R.; D' Errico, V. [University of Bologna, Department of Physics, Bologna (Italy)

    2010-09-15

    Physical methods of diagnosis are more and more frequently applied in the field of Cultural Heritage either for scientific investigations or for restoration and conservation purposes. X-ray Computed Tomography (CT) is one of the most powerful non-destructive testing techniques for the full-volume inspection of an object, as it is able to give morphological and physical information on the inner structure of the investigated sample. The great variety of size and composition that characterizes archaeological findings and art objects requires the development of tomographic systems specifically designed for Cultural Heritage analysis. In the last few years our research group has developed several acquisition systems for Digital Radiography and X-ray CT. We are able to perform high resolution micro-tomography of small objects (voxel size of few microns) as well as CT of large objects (up to 2 m of size). In this paper we will mainly focus the attention on the results of the investigation recently performed on two Japanese wooden statues with our CT system for large works of art. The CT analysis was carried out on site at the Conservation and Restoration Center ''La Venaria Reale'', where the statues have been restored before their exposition at the Oriental Art Museum in Turin. (orig.)

  7. Odontoid Fracture: Computed Tomography

    Directory of Open Access Journals (Sweden)

    Jonathan Peña

    2016-09-01

    Full Text Available History of present illness: An 84-year-old male presented with left-sided posterior head, neck, and back pain after a ground level fall. Exam was notable for left parietal scalp laceration and midline cervical spine tenderness with no obvious deformities. He was neurovascularly intact, and placed in an Aspen Collar with strict spine precautions. Significant findings: Computed Tomography (CT of the cervical spine showed a stable, acute, non-displaced fracture of the odontoid process extending into the body of C2, consistent with a Type III Odontoid Fracture. He was evaluated by orthopedic spine service who recommended conservative, non-operative management. Discussion: The cervical spine is composed of seven vertebrae, with C1 and C2 commonly referred to as the Atlas and Axis, respectively. Unique to C2 is a bony prominence, the Odontoid Process (Dens. Hyperextension or hyperflexion injuries can induce significant stress causing fractures. Odontoid fractures comprise approximately 10% of vertebral fractures, and there are three types with varying stability.1 Type 1 is the rarest and is a fracture involving the superior segment of the Dens. It is considered a stable fracture. Type 2 is the most common and is a fracture involving the base of the odontoid process, below the transverse component of the cruciform ligament. This fracture is unstable and requires operative stabilization. 2 Type 3 odontoid fractures are classified by a fracture of the Odontoid process, as well as the lateral masses of the C2. Determining the stability of a Type III Odontoid fracture requires radiographic evaluation. Strict cervical spine precautions must be adhered to until adequate imaging and surgical consultation is obtained. CT of the of cervical spine fractures poses several advantages to plain film radiography due to the ability to view the anatomy in three planes. 3 However, if there is concern for ligamentous injury, MRI is the preferred modality.3

  8. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Children's (Pediatric) CT (Computed Tomography) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  9. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... risks? What are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known ... newborns, infants and older children. top of page What are some common uses of the procedure? CT ...

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Pediatric computed tomography (CT) is a fast, painless exam that uses special x-ray equipment to create ... your doctor and the technologist prior to the exam if your child has a known allergy to ...

  12. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray ... Materials Anesthesia Safety Children and Radiation Safety Images related to Children's (Pediatric) CT (Computed Tomography) Videos related ...

  13. Computed tomography of the chest

    International Nuclear Information System (INIS)

    Norsworthy, R.

    1984-01-01

    Computed tomography of the chest can be useful in gaining detailed information of lung and mediastinal pathology, and in following up lesions during and after treatment. Considerations for dynamic and standard techniques are presented

  14. Clinical application of computed tomography for the diagnosis of feline hepatic lipidosis.

    Science.gov (United States)

    Nakamura, Momoko; Chen, Hui-Min; Momoi, Yasuyuki; Iwasaki, Toshiroh

    2005-11-01

    The usefulness of computed tomography (CT) for the diagnosis of feline hepatic lipidosis (FHL) was evaluated. Liver CT number was 54.7+/-5.6 HU (mean+/-SD) in 26 healthy cats. We fast 6 healthy cats for 72 hr to induced FHL experimentally and the cats were assessed by CT and serum biochemical analysis. Liver CT number of the six cats was 53.8+/-3.0 HU before fasting, 46.8+/-2.4 HU after fasting, and 50.2+/-3.6 HU two weeks after restarted feeding. The decreased CT number was associated with the elevation of serum non-esterified fatty acid (NEFA) and beta-hydroxybutyrate levels. These results indicate that measurement of CT number of the liver is an effective procedure for the diagnosis of FHL.

  15. Clinical application of computed tomography for the diagnosis of feline hepatic lipidosis

    International Nuclear Information System (INIS)

    Nakamura, M.; Chen, H.M.; Momoi, Y.; Iwasaki, T.

    2005-01-01

    The usefulness of computed tomography (CT) for the diagnosis of feline hepatic lipidosis (FHL) was evaluated. Liver CT number was 54.7 +- 5.6 HU (mean +- SD) in 26 healthy cats. We fast 6 healthy cats for 72 hr to induced FHL experimentally and the cats were assessed by CT and serum biochemical analysis. Liver CT number of the six cats was 53.8 +- 3.0 HU before fasting, 46.8 +- 2.4 HU after fasting, and 50.2 +- 3.6 HU two weeks after restarted feeding. The decreased CT number was associated with the elevation of serum non-esterified fatty acid (NEFA) and beta-hydroxybutyrate levels. These results indicate that measurement of CT number of the liver is an effective procedure for the diagnosis of FHL

  16. Application of x-ray computed tomography based on the refraction contrast to biomedicine

    Science.gov (United States)

    Hashimoto, Eiko; Maksimenko, Anton; Sugiyama, Hiroshi; Hyodo, Kazuyuki; Shimao, Daisuke; Yuasa, Tetsuya; Nishino, Yoshinori; Ishikawa, Tetsuya; Mori, Koichi; Arai, Yoshinori; Hirano, Keiichi; Ando, Masami

    2006-03-01

    We have developed X-ray refraction based computed tomography (CT) which is able to visualize soft tissue in between hard tissue. The experimental system consists of Si(220) diffraction double-crystals called the DEI (diffraction-enhanced imaging) method, object locating in between them and a CCD camera to acquire data of 900 x-ray images. The x-ray energy used was 17.5 keV. The algorithm used to reconstruct CT images has been invented by A. Maksimenko et al.. We successfully visualized calcification and distribution of breast cancer nest which are the inner structure. It has much higher contrast which in comparison with the conventional absorption based CT system.

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  20. High pressure-elevated temperature x-ray micro-computed tomography for subsurface applications.

    Science.gov (United States)

    Iglauer, Stefan; Lebedev, Maxim

    2017-12-28

    Physical, chemical and mechanical pore-scale (i.e. micrometer-scale) mechanisms in rock are of key importance in many, if not all, subsurface processes. These processes are highly relevant in various applications, e.g. hydrocarbon recovery, CO 2 geo-sequestration, geophysical exploration, water production, geothermal energy production, or the prediction of the location of valuable hydrothermal deposits. Typical examples are multi-phase flow (e.g. oil and water) displacements driven by buoyancy, viscous or capillary forces, mineral-fluid interactions (e.g. mineral dissolution and/or precipitation over geological times), geo-mechanical rock behaviour (e.g. rock compaction during diagenesis) or fines migration during water production, which can dramatically reduce reservoir permeability (and thus reservoir performance). All above examples are 3D processes, and 2D experiments (as traditionally done for micro-scale investigations) will thus only provide qualitative information; for instance the percolation threshold is much lower in 3D than in 2D. However, with the advent of x-ray micro-computed tomography (μCT) - which is now routinely used - this limitation has been overcome, and such pore-scale processes can be observed in 3D at micrometer-scale. A serious complication is, however, the fact that in the subsurface high pressures and elevated temperatures (HPET) prevail, due to the hydrostatic and geothermal gradients imposed upon it. Such HPET-reservoir conditions significantly change the above mentioned physical and chemical processes, e.g. gas density is much higher at high pressure, which strongly affects buoyancy and wettability and thus gas distributions in the subsurface; or chemical reactions are significantly accelerated at increased temperature, strongly affecting fluid-rock interactions and thus diagenesis and deposition of valuable minerals. It is thus necessary to apply HPET conditions to the aforementioned μCT experiments, to be able to mimic subsurface

  1. High performance graphics processor based computed tomography reconstruction algorithms for nuclear and other large scale applications.

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Edward S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Orr, Laurel J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thompson, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-09-01

    The goal of this work is to develop a fast computed tomography (CT) reconstruction algorithm based on graphics processing units (GPU) that achieves significant improvement over traditional central processing unit (CPU) based implementations. The main challenge in developing a CT algorithm that is capable of handling very large datasets is parallelizing the algorithm in such a way that data transfer does not hinder performance of the reconstruction algorithm. General Purpose Graphics Processing (GPGPU) is a new technology that the Science and Technology (S&T) community is starting to adopt in many fields where CPU-based computing is the norm. GPGPU programming requires a new approach to algorithm development that utilizes massively multi-threaded environments. Multi-threaded algorithms in general are difficult to optimize since performance bottlenecks occur that are non-existent in single-threaded algorithms such as memory latencies. If an efficient GPU-based CT reconstruction algorithm can be developed; computational times could be improved by a factor of 20. Additionally, cost benefits will be realized as commodity graphics hardware could potentially replace expensive supercomputers and high-end workstations. This project will take advantage of the CUDA programming environment and attempt to parallelize the task in such a way that multiple slices of the reconstruction volume are computed simultaneously. This work will also take advantage of the GPU memory by utilizing asynchronous memory transfers, GPU texture memory, and (when possible) pinned host memory so that the memory transfer bottleneck inherent to GPGPU is amortized. Additionally, this work will take advantage of GPU-specific hardware (i.e. fast texture memory, pixel-pipelines, hardware interpolators, and varying memory hierarchy) that will allow for additional performance improvements.

  2. Application of ray tracing towards a correction for refracting effects in computed tomography with diffracting sources

    International Nuclear Information System (INIS)

    Andersen, A.H.

    1983-01-01

    Ray tracing methods are investigated in forward and inverse processes and applied for image restoration and resolution enhancement in computed tomography with diffracting sources. Within the geometrical optics approximation for a given refractive field, a mathematical model for the forward propagation and inverse reconstruction process is presented. For a finite set of rays in a discrete image representation, an algebraic reconstruction technique is derived which is analogous to the inverse process for a continuum of rays. The geometrical theory of diffraction is invoked to describe ray patterns arising from the introduction of object discontinuity surfaces. We have compared the performance of existing recursive ray tracing techniques for the reconstruction of objects exhibiting discontinuity boundaries. A novel ray tracing and reconstruction technique is presented which enjoys significant computational savings over traditional implementations incorporating tedious ray linking procedures. Simulation studies illustrate the macro-structural distortion and loss of fine resolution when ray refraction is unaccounted for. Restoration and resolution enhancement is achieved with a recursive ray tracing approach. Successful experimental studies with tissue equivalent phantoms are presented. The comparison of simulation and experimental results demonstrated the reasonable assumption of the geometrical optics approximation. Simulation results for larger refractive deviations are encouraging

  3. Preliminary evaluation of cone beam computed tomography in three-dimensional cephalometry for clinical application.

    Science.gov (United States)

    Li, Na; Hu, Bo; Mi, Fanglin; Song, Jinlin

    2017-05-01

    The present study was conducted to evaluate the three-dimensional (3D) cephalometry accuracy of cone-beam computed tomography (CBCT). A total of 40 newly diagnosed orthodontic patients (including 18 males and 22 females; age range, 12-18 years) were subjected to CBCT scanning and X-ray imaging in order to obtain lateral cephalograms. The 3D CBCT cephalograms were reconstructed and measured with in vivo 5.1 software, and compared with the results from the conventional 2D lateral cephalograms. Measurements in the two images were performed twice using the Steiner and Tweed standards and a single analyzer paired t-test was used to analyze the differences between the two cephalometric methods. The results indicated that the two methods showed significant differences in all 12 angle and 5 linear measurements (P<0.05). These findings indicated that CBCT is a more accurate technique compared with the conventional 2D method. In conclusion, CBCT may provide diagnostic and treatment information for maxillofacial deformities by using fast computer-aided analysis platform.

  4. Central nervous system involvement in systemic lupus erythematosus. The application of cranial computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, S.; Ishigatsubo, Y.; Katou, K.; Sakamoto, H.; Chiba, J. (Yokohama City Univ. (Japan). Faculty of Medicine)

    1982-06-01

    Cranial computed tomography scans were performed on 47 patients with systemic lupus erythematosus (SLE). Abnormal findings in the computed tomograms (CT) were observed in 17 patients (36.2%). Cerebral atrophy was the most common feature (eight cases), followed by abnormal high density areas (five cases), abnormal low density areas (three cases), sulcal enlargement (two cases), intracranial hemorrhage (one case) and others (two cases). The abnormal cranial CT group of SLE was associated with a significantly higher incidence of urinary casts and of thrombocytopenia. In particular, the frequency of urinary casts was greater in the group with cerebral atrophy than in the group with normal CT findings, and there was a higher incidence of alopecia, leukopenia and thrombocytopenia in the group with intracranial calcifications. Neuropsychiatric involvements were noted in 70.6% of patients with CT abnormalities, but neuropsychiatric features (20.7%) and electroencephalographic abnormalities (44.8%) were also observed in patients with normal CT findings. The age at onset of SLE, the mean duration of the disease and the survival rate were not significantly different between the groups with and without CT abnormalities, but the mortality rate was significantly greater in the group with CT abnormalities, especially among those with brain atrophy. Concerning the relationship between the findings of cranial CT and corticosteroid treatment, there was no significant difference in either the total dose or the mean duration of prednisolone therapy. Although SLE patients with cerebral atrophy were taking a larger maintenance dose of corticosteroids, the differences were not statistically significant.

  5. Diagnostic value of electron-beam computed tomography (EBT). I. cardiac applications

    International Nuclear Information System (INIS)

    Enzweiler, C.N.H.; Lembcke, A.; Rogalla, P.; Taupitz, M.; Wiese, T.H.; Hammm, B.; Becker, C.R.; Reiser, M.F.; Felix, R.; Knollmann, F.D.; Georgi, M.; Weisser, G.; Lehmann, K.J.

    2004-01-01

    Electron beam tomography (EBT) directly competes with other non-invasive imaging modalities, such as multislice computed tomography, magnetic resonance imaging, and echocardiography, in the diagnostic assessment of cardiac diseases. EBT is the gold standard for the detection and quantification of coronary calcium as a preclinical sign of coronary artery disease (CAD). Its standardized examination protocols and the broad experience with this method favor EBT. First results with multislice CT indicate that this new technology may be equivalent to EBT for coronary calcium studies. The principal value of CT-based coronary calcium measurements continues to be an issue of controversy amongst radiologists and cardiologists due to lack of prospective randomized trials. Coronary angiography with EBT is characterized by a high negative predictive value and, in addition, may be indicated in some patients with manifest CAD. It remains to be shown whether coronary angiography with multislice CT is reliable and accurate enough to be introduced into the routine work-up, to replace some of the many strictly diagnostic coronary catheterizations in Germany and elsewhere. Assessment of coronary stent patency with EBT is associated with several problems and in our opinion cannot be advocated as a routine procedure. EBT may be recommended for the evaluation of coronary bypasses to look for bypass occlusions and significant stenoses, which, however, can be equally well achieved with multislice CT. Quantification of myocardial perfusion with EBT could not replace MRI or other modalities in this field. EBT has proven to be accurate, reliable and in some instances equivalent to MRI, which is the gold standard for the quantitative and qualitative evaluation of cardiac function. Some disadvantages not the least of which is the limited distribution of electron beam scanners, favor MRI for functional assessment of the heart. (orig.) [de

  6. Novel application of quantitative single-photon emission computed-tomography/computed tomography to predict early response to methimazole in Graves' disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Joo; Bang, Ji In; Kim, Ji Young; Moon, Jae Hoon [Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); So, Young [Dept. of Nuclear Medicine, Konkuk University Medical Center, Seoul (Korea, Republic of); Lee, Won Woo [Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul (Korea, Republic of)

    2017-06-15

    Since Graves' disease (GD) is resistant to antithyroid drugs (ATDs), an accurate quantitative thyroid function measurement is required for the prediction of early responses to ATD. Quantitative parameters derived from the novel technology, single-photon emission computed tomography/computed tomography (SPECT/CT), were investigated for the prediction of achievement of euthyroidism after methimazole (MMI) treatment in GD. A total of 36 GD patients (10 males, 26 females; mean age, 45.3 ± 13.8 years) were enrolled for this study, from April 2015 to January 2016. They underwent quantitative thyroid SPECT/CT 20 minutes post-injection of {sup 99m}Tc-pertechnetate (5 mCi). Association between the time to biochemical euthyroidism after MMI treatment and uptake, standardized uptake value (SUV), functional thyroid mass (SUVmean × thyroid volume) from the SPECT/CT, and clinical/biochemical variables, were investigated. GD patients had a significantly greater %uptake (6.9 ± 6.4%) than historical control euthyroid patients (n = 20, 0.8 ± 0.5%, p < 0.001) from the same quantitative SPECT/CT protocol. Euthyroidism was achieved in 14 patients at 156 ± 62 days post-MMI treatment, but 22 patients had still not achieved euthyroidism by the last follow-up time-point (208 ± 80 days). In the univariate Cox regression analysis, the initial MMI dose (p = 0.014), %uptake (p = 0.015), and functional thyroid mass (p = 0.016) were significant predictors of euthyroidism in response to MMI treatment. However, only uptake remained significant in a multivariate Cox regression analysis (p = 0.034). A uptake cutoff of 5.0% dichotomized the faster responding versus the slower responding GD patients (p = 0.006). A novel parameter of thyroid uptake from quantitative SPECT/CT is a predictive indicator of an early response to MMI in GD patients.

  7. Application of C-arm computed tomography in cardiology; Kardiale Anwendung der C-Arm-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Rieber, J. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Innenstadt, Abteilung fuer Kardiologie, Medizinische Poliklinik, Muenchen (Germany); Rohkohl, C. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Lehrstuhl fuer Mustererkennung, Department Informatik, Erlangen (Germany); Siemens AG, Healthcare Sector, Forchheim, Forchheim (Germany); Lauritsch, G. [Siemens AG, Healthcare Sector, Forchheim, Forchheim (Germany); Rittger, H. [Krankenhaus Coburg, Abteilung fuer Kardiologie, Coburg (Germany); Meissner, O. [Siemens AG, Healthcare Sector, Forchheim, Forchheim (Germany); Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2009-09-15

    C-arm computed tomography is currently being introduced into cardiac imaging and offers the potential for three-dimensional imaging of the cardiac anatomy within the interventional environment. This detailed view is necessary to support complex interventional strategies, such as transcutaneous valve replacement, interventional therapy of atrial fibrillation, implantation of biventricular pacemakers and assessment of myocardial perfusion. Currently, the major limitation of this technology is its insufficient temporal resolution which limits the visualization of fast moving parts of the heart. (orig.) [German] Durch die Entwicklung der C-Arm-Computertomographie- (CACT-)Angiographie ist es erstmals moeglich, waehrend einer Herzkatheteruntersuchung eine detaillierte dreidimensionale Darstellung der kardialen Anatomie zu erhalten. Derartige zusaetzliche Informationen koennten die Durchfuehrung der immer komplexer werdenden Strategien der interventionellen Kardiologie wirkungsvoll unterstuetzen. Hierzu zaehlen u. a. der transkutane Klappenersatz, die interventionelle Behandlung von Vorhofflimmern, die Implantation biventrikulaerer Schrittmacher sowie die Beurteilung der Myokardperfusion. Die derzeit groesste Limitation dieser Methode ist die relativ geringe zeitliche Aufloesung, die aufgrund der Bewegung des Herzens die Anwendung dieser Technologie einschraenkt. (orig.)

  8. Clinical application of electron beam computed tomography in diagnosis of truncus arteriosus

    International Nuclear Information System (INIS)

    Zhang Gejun; Dai Ruping; Cao Cheng; Qi Xiaoou; Bai Hua; Ma Zhanhong; Chen Yao; Mu Feng; Ren Li

    2005-01-01

    Objective: To evaluate value of electron beam computed tomography (EBCT) in diagnosis of truncus arteriosus (TA). Methods: Ten cases of TA with age ranging from 2-month to 24 years were studied. All cases were examined and diagnosed with Imatron C-150 scanner using contrastmedia. The results of EBCT were analyzed and compared with the results of echocardiography (in 10 cases), cardiovascular angiography (in 3 cases) and surgery findings (in 1 case ). Results: EBCT yielded qualitative diagnosis and classification in all 10 cases. Echocardiography revealed qualitative diagnosis in 9 cases, however its classification was accordant to EBCT just in 5 cases. The concomitant abnormalities of TA were found more with EBCT than that with echocardiography. Cardiovascular angiography was performed in 3 cases, yielding inaccurate classification 2 cases. One case of TA was operated just based on the results of echocardiography, EBCT and catheterization. Conclusion: As a noninvasive method, EBCT could yield qualitative diagnosis of TA as well as classification. The results of EBCT examination combining echocardiography and catheterization could guide the operations. (authors)

  9. Design and application of Mark IV scanning system for radionuclide computed tomography of the brain

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Hoffman, E.J.; Phelps, M.E.; Ricci, A.; Reivich, M.

    1977-01-01

    The MARK IV system was built in our laboratory to provide fast and accurate radionuclide computed tomography (RCT). It is designed primarily for detecting commonly available radioactive labels such as 99 Tcsup(m), but it is also adapted to detecting positron emitters such as 18 F. The system has interlaced convergent collimation in a four-sided arrangement of 32 independent detectors which continuously rotate as a unit, detecting, processing and displaying the reconstructed data while the study progresses. During the scanning procedure, accumulated data are transferred to a digital computer for reconstruction processing. Data are corrected to equalize detector response and compensate for photon attenuation in the head. This program requires 30 seconds for completion, whereupon the final reconstruction, a 64 x 64 matrix from the single revolution, outputs to a core store and is displayed on the screen of a cathode-ray tube. As the rotation sequence continues, new data from each revolution are added to previous data and reprocessed for a new picture. Since the instrument operates at 50 s per revolution, the continuous collection and processing of data causes a new picture to appear on the display every 50 s as the study progresses. The operator may extend or curtail the duration of the examination according to the appearance of the picture. In practice, a five revolution (4.2 min.) scan is commonly used in most clinical studies. The instrument is a high sensitivity device with approximately uniform resolution (1.7 cm FWHM) throughout the section plane. Quantification of concentration of radioactivity in small regions is accurate and reproducible. The instrument has been applied to the study of alterations in cerebral vascular permeability, blood flow and blood volume, and to the study of cerebral glucose metabolism and cerebral spinal fluid distribution. (author)

  10. [Computed tomography and cranial paleoanthropology].

    Science.gov (United States)

    Cabanis, Emmanuel Alain; Badawi-Fayad, Jackie; Iba-Zizen, Marie-Thérèse; Istoc, Adrian; de Lumley, Henry; de Lumley, Marie-Antoinette; Coppens, Yves

    2007-06-01

    Since its invention in 1972, computed tomography (C.T.) has significantly evolved. With the advent of multi-slice detectors (500 times more sensitive than conventional radiography) and high-powered computer programs, medical applications have also improved. CT is now contributing to paleoanthropological research. Its non-destructive nature is the biggest advantage for studying fossil skulls. The second advantage is the possibility of image analysis, storage, and transmission. Potential disadvantages include the possible loss of files and the need to keep up with rapid technological advances. Our experience since the late 1970s, and a recent PhD thesis, led us to describe routine applications of this method. The main contributions of CT to cranial paleoanthropology are five-fold: --Numerical anatomy with rapid acquisition and high spatial resolution (helicoidal and multidetector CT) offering digital storage and stereolithography (3D printing). --Numerical biometry (2D and 3D) can be used to create "normograms" such as the 3D craniofacial reference model used in maxillofacial surgery. --Numerical analysis offers thorough characterization of the specimen and its state of conservation and/or restoration. --From "surrealism" to virtual imaging, anatomical structures can be reconstructed, providing access to hidden or dangerous zones. --The time dimension (4D imaging) confers movement and the possibility for endoscopic simulation and internal navigation (see Iconography). New technical developments will focus on data processing and networking. It remains our duty to deal respectfully with human fossils.

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  15. Applications of linac-mounted kilovoltage Cone-beam Computed Tomography in modern radiation therapy: A review.

    Science.gov (United States)

    Srinivasan, Kavitha; Mohammadi, Mohammad; Shepherd, Justin

    2014-01-01

    The use of Cone-beam Computed Tomography (CBCT) in radiotherapy is increasing due to the widespread implementation of kilovoltage systems on the currently available linear accelerators. Cone beam CT acts as an effective Image-Guided Radiotherapy (IGRT) tool for the verification of patient position. It also opens up the possibility of real-time re-optimization of treatment plans for Adaptive Radiotherapy (ART). This paper reviews the most prominent applications of CBCT (linac-mounted) in radiation therapy, focusing on CBCT-based planning and dose calculation studies. This is followed by a concise review of the main issues associated with CBCT, such as imaging artifacts, dose and image quality. It explores how medical physicists and oncologists can best apply CBCT for therapeutic applications.

  16. Improving the quantitative accuracy of optical-emission computed tomography by incorporating an attenuation correction: application to HIF1 imaging

    Science.gov (United States)

    Kim, E.; Bowsher, J.; Thomas, A. S.; Sakhalkar, H.; Dewhirst, M.; Oldham, M.

    2008-10-01

    Optical computed tomography (optical-CT) and optical-emission computed tomography (optical-ECT) are new techniques for imaging the 3D structure and function (including gene expression) of whole unsectioned tissue samples. This work presents a method of improving the quantitative accuracy of optical-ECT by correcting for the 'self'-attenuation of photons emitted within the sample. The correction is analogous to a method commonly applied in single-photon-emission computed tomography reconstruction. The performance of the correction method was investigated by application to a transparent cylindrical gelatin phantom, containing a known distribution of attenuation (a central ink-doped gelatine core) and a known distribution of fluorescing fibres. Attenuation corrected and uncorrected optical-ECT images were reconstructed on the phantom to enable an evaluation of the effectiveness of the correction. Significant attenuation artefacts were observed in the uncorrected images where the central fibre appeared ~24% less intense due to greater attenuation from the surrounding ink-doped gelatin. This artefact was almost completely removed in the attenuation-corrected image, where the central fibre was within ~4% of the others. The successful phantom test enabled application of attenuation correction to optical-ECT images of an unsectioned human breast xenograft tumour grown subcutaneously on the hind leg of a nude mouse. This tumour cell line had been genetically labelled (pre-implantation) with fluorescent reporter genes such that all viable tumour cells expressed constitutive red fluorescent protein and hypoxia-inducible factor 1 transcription-produced green fluorescent protein. In addition to the fluorescent reporter labelling of gene expression, the tumour microvasculature was labelled by a light-absorbing vasculature contrast agent delivered in vivo by tail-vein injection. Optical-CT transmission images yielded high-resolution 3D images of the absorbing contrast agent, and

  17. Development of a Computed Tomography Simulator: SimCT, Application to Health Monitoring and Remaining Life Assessment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this activity is to develop a quantitative NDE simulation tool for computed tomography suitable for desktop work using realistic geometry...

  18. Characterization of a spectroscopic detector for application in x-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, A. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fix, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, W. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Azevedo, S. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martz, H. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-21

    Recent advances in cadmium telluride (CdTe) energy-discriminating pixelated detectors have enabled the possibility of Multi-Spectral X-ray Computed Tomography (MSXCT) to incorporate spectroscopic information into CT. MultiX ME 100 V2 is a CdTe-based spectroscopic x-ray detector array capable of recording energies from 20 to 160 keV in 1.1 keV energy bin increments. Hardware and software have been designed to perform radiographic and computed tomography tasks with this spectroscopic detector. Energy calibration is examined using the end-point energy of a bremsstrahlung spectrum and radioisotope spectral lines. When measuring the spectrum from Am-241 across 500 detector elements, the standard deviation of the peak-location and FWHM measurements are ±0.4 and ±0.6 keV, respectively. As these values are within the energy bin size (1.1 keV), detector elements are consistent with each other. The count rate is characterized, using a nonparalyzable model with a dead time of 64 ± 5 ns. This is consistent with the manufacturer’s quoted per detector-element linear-deviation at 2 Mpps (million photons per sec) of 8.9% (typical) and 12% (max). When comparing measured and simulated spectra, a low-energy tail is visible in the measured data due to the spectral response of the detector. If no valid photon detections are expected in the low-energy tail, then a background subtraction may be applied to allow for a possible first-order correction. If photons are expected in the low-energy tail, a detailed model must be implemented. A radiograph of an aluminum step wedge with a maximum height of about 20 mm shows an underestimation of attenuation by about 10% at 60 keV. This error is due to partial energy deposition from higher-energy (> 60 keV) photons into a lower-energy (~60 keV) bin, reducing the apparent attenuation. A radiograph of a PTFE cylinder taken using a bremsstrahlung spectrum from an x-ray voltage of 100 kV filtered by 1.3 mm Cu is reconstructed using Abel inversion

  19. Characterization of a spectroscopic detector for application in x-ray computed tomography

    Science.gov (United States)

    Dooraghi, Alex A.; Fix, Brian J.; Smith, Jerel A.; Brown, William D.; Azevedo, Stephen G.; Martz, Harry E.

    2017-09-01

    Recent advances in cadmium telluride (CdTe) energy-discriminating pixelated detectors have enabled the possibility of Multi-Spectral X-ray Computed Tomography (MSXCT) to incorporate spectroscopic information into CT. MultiX ME 100 V2 is a CdTe-based spectroscopic x-ray detector array capable of recording energies from 20 to 160 keV in 1.1 keV energy bin increments. Hardware and software have been designed to perform radiographic and computed tomography tasks with this spectroscopic detector. Energy calibration is examined using the end-point energy of a bremsstrahlung spectrum and radioisotope spectral lines. When measuring the spectrum from Am-241 across 500 detector elements, the standard deviation of the peak-location and FWHM measurements are +/- 0.4 and +/- 0.6 keV, respectively. As these values are within the energy bin size (1.1 keV), detector elements are consistent with each other. The count rate is characterized, using a nonparalyzable model with a dead time of 64 +/- 5 ns. This is consistent with the manufacturer's quoted per detector-element linear-deviation at 2 Mpps (million photons per sec) of 8.9 % (typical) and 12 % (max). When comparing measured and simulated spectra, a low-energy tail is visible in the measured data due to the spectral response of the detector. If no valid photon detections are expected in the low-energy tail, then a background subtraction may be applied to allow for a possible first-order correction. If photons are expected in the low-energy tail, a detailed model must be implemented. A radiograph of an aluminum step wedge with a maximum height of 20 mm shows an underestimation of attenuation by about 10 % at 60 keV. This error is due to partial energy deposition from higher energy (>60 keV) photons into a lower-energy ( 60 keV) bin, reducing the apparent attenuation. A radiograph of a polytetrafluoroethylene (PTFE) cylinder taken using a bremsstrahlung spectrum from an x-ray voltage of 100 kV filtered by 1.3 mm Cu is

  20. Pulmonary amyloidosis: computed tomography findings

    International Nuclear Information System (INIS)

    Marchiori, Edson; Ferreira, Angela; Crespo, Sheila Jandira Vianna

    2003-01-01

    We report the computed tomography findings of five patients with pathology proven pulmonary amyloidosis. Tracheobronchial amyloidosis with calcified nodules and plaques in the tracheal wall were seen in two patients. Two other patients had diffuse parenchymal disease with calcified lesions, one had reticular and nodular sub pleural opacities whereas the other had nodular interlobular septal thickening and a parenchymal consolidation. The latter presented the nodular type of the disease with multiple sharp nodules scattered throughout the lungs and interspersed calcifications. The computed tomography findings observed were not specific but strongly suggestive of amyloidosis. (author)

  1. Clinical Application of Cone-Beam Computed Tomography of the Rabbit Head: Part 1 - Normal Dentition.

    Science.gov (United States)

    Riggs, G G; Arzi, Boaz; Cissell, Derek D; Hatcher, David C; Kass, Philip H; Zhen, Amy; Verstraete, Frank J M

    2016-01-01

    Domestic rabbits ( Oryctolagus cuniculus ) are increasingly popular as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental diseases. Diagnostic approaches for dental disease include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). CT overcomes many limitations of standard radiography by permitting cross-sectional images of the rabbit head in multiple planes without superimposition of anatomic structures. Cone-beam CT (CBCT) is an oral and maxillofacial imaging modality that produces high-resolution images. The objective of this study was to describe and compare the normal anatomic features of the dentition and surrounding maxillofacial structures in healthy rabbits on CBCT and conventional CT. Ten New Zealand white rabbit cadaver heads were scanned using CBCT and conventional CT. Images were evaluated using Anatomage Invivo 5 software. The maxillofacial anatomy was labeled on CBCT images, and the mean lengths and widths of the teeth were determined. The visibility of relevant dental and anatomic features (pulp cavity, germinal center, tooth outline, periodontal ligament) were scored and compared between conventional CT and CBCT. The thinnest teeth were the maxillary second incisor teeth at 1.29 ± 0.26 mm and the maxillary third molar teeth at 1.04 ± 0.10 mm. In general, it was found that CBCT was superior to conventional CT when imaging the dentition. Importantly, the periodontal ligament was significantly ( P  < 0.01) more visible on CBCT than on conventional CT. Ability to see the periodontal ligament with such detail may allow earlier detection and treatment of periodontal disease in rabbits. This study is the first of its kind and shows the feasibility and yield of CBCT when evaluating the maxillofacial features and dentition in rabbits.

  2. Clinical Application of Cone-Beam Computed Tomography of the Rabbit Head: Part 1 - Normal Dentition

    Directory of Open Access Journals (Sweden)

    GG Comet Riggs

    2016-10-01

    Full Text Available Domestic rabbits (Oryctolagus cuniculus are increasingly popular as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental diseases. Diagnostic approaches for dental disease include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT. CT overcomes many limitations of standard radiography by permitting cross-sectional images of the rabbit head in multiple planes without superimposition of anatomic structures. Cone-beam CT (CBCT is an oral and maxillofacial imaging modality that produces high-resolution images. The objective of this study was to describe and compare the normal anatomic features of the dentition and surrounding maxillofacial structures in healthy rabbits on CBCT and conventional CT. Ten New Zealand white rabbit cadaver heads were scanned using CBCT and conventional CT. Images were evaluated using Anatomage Invivo 5 software. The maxillofacial anatomy was labeled on CBCT images and the mean lengths and widths of the teeth were determined. The visibility of relevant dental and anatomic features (pulp cavity, germinal center, tooth outline, periodontal ligament were scored and compared between conventional CT and CBCT. The thinnest teeth were the maxillary second incisor teeth at 1.29 ± 0.26 mm and the maxillary third molar teeth at 1.04 ±0.10 mm. In general, it was found that CBCT was superior to conventional CT when imaging the dentition. Importantly, the periodontal ligament was significantly (P<0.01 more visible on CBCT than on conventional CT. Ability to see the periodontal ligament with such detail may allow earlier detection and treatment of periodontal disease in rabbits. This study is the first of its kind and shows the feasibility and yield of CBCT when evaluating the maxillofacial features and dentition in rabbits.

  3. Spectral response model for a multibin photon-counting spectral computed tomography detector and its applications.

    Science.gov (United States)

    Liu, Xuejin; Persson, Mats; Bornefalk, Hans; Karlsson, Staffan; Xu, Cheng; Danielsson, Mats; Huber, Ben

    2015-07-01

    Variations among detector channels in computed tomography can lead to ring artifacts in the reconstructed images and biased estimates in projection-based material decomposition. Typically, the ring artifacts are corrected by compensation methods based on flat fielding, where transmission measurements are required for a number of material-thickness combinations. Phantoms used in these methods can be rather complex and require an extensive number of transmission measurements. Moreover, material decomposition needs knowledge of the individual response of each detector channel to account for the detector inhomogeneities. For this purpose, we have developed a spectral response model that binwise predicts the response of a multibin photon-counting detector individually for each detector channel. The spectral response model is performed in two steps. The first step employs a forward model to predict the expected numbers of photon counts, taking into account parameters such as the incident x-ray spectrum, absorption efficiency, and energy response of the detector. The second step utilizes a limited number of transmission measurements with a set of flat slabs of two absorber materials to fine-tune the model predictions, resulting in a good correspondence with the physical measurements. To verify the response model, we apply the model in two cases. First, the model is used in combination with a compensation method which requires an extensive number of transmission measurements to determine the necessary parameters. Our spectral response model successfully replaces these measurements by simulations, saving a significant amount of measurement time. Second, the spectral response model is used as the basis of the maximum likelihood approach for projection-based material decomposition. The reconstructed basis images show a good separation between the calcium-like material and the contrast agents, iodine and gadolinium. The contrast agent concentrations are reconstructed with more

  4. The possibility of application of spiral brain computed tomography to traumatic brain injury.

    Science.gov (United States)

    Lim, Daesung; Lee, Soo Hoon; Kim, Dong Hoon; Choi, Dae Seub; Hong, Hoon Pyo; Kang, Changwoo; Jeong, Jin Hee; Kim, Seong Chun; Kang, Tae-Sin

    2014-09-01

    The spiral computed tomography (CT) with the advantage of low radiation dose, shorter test time required, and its multidimensional reconstruction is accepted as an essential diagnostic method for evaluating the degree of injury in severe trauma patients and establishment of therapeutic plans. However, conventional sequential CT is preferred for the evaluation of traumatic brain injury (TBI) over spiral CT due to image noise and artifact. We aimed to compare the diagnostic power of spiral facial CT for TBI to that of conventional sequential brain CT. We evaluated retrospectively the images of 315 traumatized patients who underwent both brain CT and facial CT simultaneously. The hemorrhagic traumatic brain injuries such as epidural hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, and contusional hemorrhage were evaluated in both images. Statistics were performed using Cohen's κ to compare the agreement between 2 imaging modalities and sensitivity, specificity, positive predictive value, and negative predictive value of spiral facial CT to conventional sequential brain CT. Almost perfect agreement was noted regarding hemorrhagic traumatic brain injuries between spiral facial CT and conventional sequential brain CT (Cohen's κ coefficient, 0.912). To conventional sequential brain CT, sensitivity, specificity, positive predictive value, and negative predictive value of spiral facial CT were 92.2%, 98.1%, 95.9%, and 96.3%, respectively. In TBI, the diagnostic power of spiral facial CT was equal to that of conventional sequential brain CT. Therefore, expanded spiral facial CT covering whole frontal lobe can be applied to evaluate TBI in the future. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Cone beam computed tomography in veterinary dentistry

    NARCIS (Netherlands)

    van Thielen, B.; Siguenza, F.; Hassan, B.

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal

  6. Computational fluid dynamics modelling of perfusion measurements in dynamic contrast-enhanced computed tomography: development, validation and clinical applications

    International Nuclear Information System (INIS)

    Peladeau-Pigeon, M; Coolens, C

    2013-01-01

    Dynamic contrast-enhanced computed tomography (DCE-CT) is an imaging tool that aids in evaluating functional characteristics of tissue at different stages of disease management: diagnostic, radiation treatment planning, treatment effectiveness, and monitoring. Clinical validation of DCE-derived perfusion parameters remains an outstanding problem to address prior to perfusion imaging becoming a widespread standard as a non-invasive quantitative measurement tool. One approach to this validation process has been the development of quality assurance phantoms in order to facilitate controlled perfusion ex vivo. However, most of these systems fail to establish and accurately replicate physiologically relevant capillary permeability and exchange performance. The current work presents the first step in the development of a prospective suite of physics-based perfusion simulations based on coupled fluid flow and particle transport phenomena with the goal of enhancing the understanding of clinical contrast agent kinetics. Existing knowledge about a controllable, two-compartmental fluid exchange phantom was used to validate the computational fluid dynamics (CFD) simulation model presented herein. The sensitivity of CFD-derived contrast uptake curves to contrast injection parameters, including injection duration and flow rate, were quantified and found to be within 10% accuracy. The CFD model was employed to evaluate two commonly used clinical kinetic algorithms used to derive perfusion parameters: Fick's principle and the modified Tofts model. Neither kinetic model was able to capture the true transport phenomena it aimed to represent but if the overall contrast concentration after injection remained identical, then successive DCE-CT evaluations could be compared and could indeed reflect differences in regional tissue flow. This study sets the groundwork for future explorations in phantom development and pharmaco-kinetic modelling, as well as the development of novel contrast

  7. Computational fluid dynamics modelling of perfusion measurements in dynamic contrast-enhanced computed tomography: development, validation and clinical applications.

    Science.gov (United States)

    Peladeau-Pigeon, M; Coolens, C

    2013-09-07

    Dynamic contrast-enhanced computed tomography (DCE-CT) is an imaging tool that aids in evaluating functional characteristics of tissue at different stages of disease management: diagnostic, radiation treatment planning, treatment effectiveness, and monitoring. Clinical validation of DCE-derived perfusion parameters remains an outstanding problem to address prior to perfusion imaging becoming a widespread standard as a non-invasive quantitative measurement tool. One approach to this validation process has been the development of quality assurance phantoms in order to facilitate controlled perfusion ex vivo. However, most of these systems fail to establish and accurately replicate physiologically relevant capillary permeability and exchange performance. The current work presents the first step in the development of a prospective suite of physics-based perfusion simulations based on coupled fluid flow and particle transport phenomena with the goal of enhancing the understanding of clinical contrast agent kinetics. Existing knowledge about a controllable, two-compartmental fluid exchange phantom was used to validate the computational fluid dynamics (CFD) simulation model presented herein. The sensitivity of CFD-derived contrast uptake curves to contrast injection parameters, including injection duration and flow rate, were quantified and found to be within 10% accuracy. The CFD model was employed to evaluate two commonly used clinical kinetic algorithms used to derive perfusion parameters: Fick's principle and the modified Tofts model. Neither kinetic model was able to capture the true transport phenomena it aimed to represent but if the overall contrast concentration after injection remained identical, then successive DCE-CT evaluations could be compared and could indeed reflect differences in regional tissue flow. This study sets the groundwork for future explorations in phantom development and pharmaco-kinetic modelling, as well as the development of novel contrast

  8. Computational fluid dynamics modelling of perfusion measurements in dynamic contrast-enhanced computed tomography: development, validation and clinical applications

    Science.gov (United States)

    Peladeau-Pigeon, M.; Coolens, C.

    2013-09-01

    Dynamic contrast-enhanced computed tomography (DCE-CT) is an imaging tool that aids in evaluating functional characteristics of tissue at different stages of disease management: diagnostic, radiation treatment planning, treatment effectiveness, and monitoring. Clinical validation of DCE-derived perfusion parameters remains an outstanding problem to address prior to perfusion imaging becoming a widespread standard as a non-invasive quantitative measurement tool. One approach to this validation process has been the development of quality assurance phantoms in order to facilitate controlled perfusion ex vivo. However, most of these systems fail to establish and accurately replicate physiologically relevant capillary permeability and exchange performance. The current work presents the first step in the development of a prospective suite of physics-based perfusion simulations based on coupled fluid flow and particle transport phenomena with the goal of enhancing the understanding of clinical contrast agent kinetics. Existing knowledge about a controllable, two-compartmental fluid exchange phantom was used to validate the computational fluid dynamics (CFD) simulation model presented herein. The sensitivity of CFD-derived contrast uptake curves to contrast injection parameters, including injection duration and flow rate, were quantified and found to be within 10% accuracy. The CFD model was employed to evaluate two commonly used clinical kinetic algorithms used to derive perfusion parameters: Fick's principle and the modified Tofts model. Neither kinetic model was able to capture the true transport phenomena it aimed to represent but if the overall contrast concentration after injection remained identical, then successive DCE-CT evaluations could be compared and could indeed reflect differences in regional tissue flow. This study sets the groundwork for future explorations in phantom development and pharmaco-kinetic modelling, as well as the development of novel contrast

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... diagnose sinusitis . evaluate sinuses that are filled with fluid or thickened sinus membranes . detect the presence of ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... openings. top of page What are some common uses of the procedure? CT of the sinuses is ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ...

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... rays). top of page What are some common uses of the procedure? CT scanning of the head ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... beam follows a spiral path. A special computer program processes this large volume of data to create ... technologist or nurse, under the direction of a physician, may offer you some medication to help you ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... If contrast material is used, depending on the type of exam, it will be swallowed, injected through ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  2. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. If ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... artifacts on the images. This loss of image quality can resemble the blurring seen on a photograph ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... cause blurring of the images and degrade the quality of the examination the same way that it ...

  11. Computed tomography:the details.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2007-07-01

    Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

  12. Laryngopyocele: signs on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nazaroglu, Hasan E-mail: hnazarog@dicle.edu.tr; Oezates, Mustafa; Uyar, Asur; Deger, Emin; Simsek, Masum

    2000-01-01

    A laryngocele is an air-filled dilation of the saccule of the larynx. An infected laryngocele is called a laryngopyocele. Our experience with a case of laryngopyocele with signs on computed tomography before and after antibiotic therapy is presented since laryngopyocele is more unusual.

  13. Laryngopyocele: signs on computed tomography

    International Nuclear Information System (INIS)

    Nazaroglu, Hasan; Oezates, Mustafa; Uyar, Asur; Deger, Emin; Simsek, Masum

    2000-01-01

    A laryngocele is an air-filled dilation of the saccule of the larynx. An infected laryngocele is called a laryngopyocele. Our experience with a case of laryngopyocele with signs on computed tomography before and after antibiotic therapy is presented since laryngopyocele is more unusual

  14. Computer tomography in Caisson's disease

    International Nuclear Information System (INIS)

    Horvath, F.; Csobaly, S.; Institute for Advanced Training of Physicians, Budapest

    1981-01-01

    Computer tomography was performed on 20 patients with the early stages of Caisson osteoarthropathy, as well as in other patients with chronic bone infarcts. From their results the authors have formed the opinion that CT is valuable, not only in the diagnosis of early cases, but that it can provide significant information concerning the osteopathy and bone infarcts. (orig.) [de

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate control room, where the technologist operates the scanner and ...

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate control room, where the technologist operates the scanner and ...

  17. Integrated positron emission tomography/computed tomography for ...

    African Journals Online (AJOL)

    Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosisendemic area: A 5-year prospective observational study.

  18. Cranial computed tomography in psychiatry

    International Nuclear Information System (INIS)

    Falkai, P.; Bogerts, B.

    1993-01-01

    Computed tomography has gained importance as a diagnostic tool in psychiatry to exclude structural brain pathology, but has passed on its role in research to magnetic resonance tomography. It helps to distinguish between senile dementia of Alzheimer type and multi-infarct dementia. The enlargement of the ventricular system and cortical sulci is well established in schizophrenic and affective psychosis. Some alcohol addicts show a considerable degree of cerebral atrophy, only exceeded by demented patients, but this condition is potentially reversible. To screen psychiatric patients by CT is recommendable, as 2-10% of hospitalized psychiatric patients have structural brain disease. (orig.) [de

  19. X-ray computed tomography

    International Nuclear Information System (INIS)

    Kalender, Willi A

    2006-01-01

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  20. Dental application of novel finite element analysis software for three-dimensional finite element modeling of a dentulous mandible from its computed tomography images.

    Science.gov (United States)

    Nakamura, Keiko; Tajima, Kiyoshi; Chen, Ker-Kong; Nagamatsu, Yuki; Kakigawa, Hiroshi; Masumi, Shin-ich

    2013-12-01

    This study focused on the application of novel finite-element analysis software for constructing a finite-element model from the computed tomography data of a human dentulous mandible. The finite-element model is necessary for evaluating the mechanical response of the alveolar part of the mandible, resulting from occlusal force applied to the teeth during biting. Commercially available patient-specific general computed tomography-based finite-element analysis software was solely applied to the finite-element analysis for the extraction of computed tomography data. The mandibular bone with teeth was extracted from the original images. Both the enamel and the dentin were extracted after image processing, and the periodontal ligament was created from the segmented dentin. The constructed finite-element model was reasonably accurate using a total of 234,644 nodes and 1,268,784 tetrahedral and 40,665 shell elements. The elastic moduli of the heterogeneous mandibular bone were determined from the bone density data of the computed tomography images. The results suggested that the software applied in this study is both useful and powerful for creating a more accurate three-dimensional finite-element model of a dentulous mandible from the computed tomography data without the need for any other software.

  1. Clinical applications of cone beam computed tomography in endodontics: a comprehensive review. Part 2: applications associated with advanced endodontic problems and complications

    NARCIS (Netherlands)

    Cohenca, N.; Shemesh, H.

    2015-01-01

    The use of cone beam computed tomography (CBCT) in endodontics has been extensively reported in the literature. Compared with the traditional spiral computed tomography, limited field of view (FOV) CBCT results in a fraction of the effective absorbed dose of radiation. The purpose of this manuscript

  2. A beam optics study of a modular multi-source X-ray tube for novel computed tomography applications

    Science.gov (United States)

    Walker, Brandon J.; Radtke, Jeff; Chen, Guang-Hong; Eliceiri, Kevin W.; Mackie, Thomas R.

    2017-10-01

    A modular implementation of a scanning multi-source X-ray tube is designed for the increasing number of multi-source imaging applications in computed tomography (CT). An electron beam array coupled with an oscillating magnetic deflector is proposed as a means for producing an X-ray focal spot at any position along a line. The preliminary multi-source model includes three thermionic electron guns that are deflected in tandem by a slowly varying magnetic field and pulsed according to a scanning sequence that is dependent on the intended imaging application. Particle tracking simulations with particle dynamics analysis software demonstrate that three 100 keV electron beams are laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field of 102 G perpendicular to the beam axis. Beam modulation is accomplished using 25 μs pulse widths to a grid electrode with a reverse gate bias of -500 V and an extraction voltage of +1000 V. Projected focal spot diameters are approximately 1 mm for 138 mA electron beams and the stationary target stays within thermal limits for the 14 kW module. This concept could be used as a research platform for investigating high-speed stationary CT scanners, for lowering dose with virtual fan beam formation, for reducing scatter radiation in cone-beam CT, or for other industrial applications.

  3. Characteristics and applications of a flat panel computer tomography system; Eigenschaften und Anwendungen der Flaechendetektor-basierten Volumen-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Knollmann, F.; Valencia, R.; Obenauer, S. [Abt. Diagnostische Radiologie, Klinikum der Georg-August-Univ. Goettingen (Germany); Buhk, J.H. [Abt. Neuroradiologie, Univ. Goettingen (Germany)

    2006-09-15

    Purpose: to assess a new flat panel volume computed tomography (FP-VCT) with very high isotropic spatial resolution as well as high Z-axis coverage. Materials and Methods: The prototype of an FP-VCT scanner with a detector cell size of 0.2 mm was used for numerous phantom studies, specimen examinations, and animal research projects. Results: The high spatial resolution of the new system can be used to accurately determine solid tumor volume, thus allowing for earlier assessment of the therapeutic response. In animal experimentation, whole-body perfusion mapping of mice is feasible. The high spatial resolution also improves the classification of coronary artery atherosclerotic plaques in the isolated post mortem human heart. With the depiction of intramyocardial segments of the coronary arteries, investigations of myocardial collateral circulation are feasible. In skeletal applications, an accurate analysis of the smallest bony structures, e.g., petrous bone and dental preparations, can be successfully performed, as well as investigations of repetitive studies of fracture healing and the treatment of osteoporosis. Conclusion: The introduction of FP-VCT opens up new applications for CT, including the field of molecular imaging, which are highly attractive for future clinical applications. Present limitations include limited temporal resolution and necessitate further improvement of the system. (orig.)

  4. Discovering Hominins - Application of Medical Computed Tomography (CT) to Fossil-Bearing Rocks from the Site of Malapa, South Africa.

    Science.gov (United States)

    Smilg, Jacqueline S; Berger, Lee R

    2015-01-01

    In the South African context, computed tomography (CT) has been used applied to individually prepared fossils and small rocks containing fossils, but has not been utilized on large breccia blocks as a means of discovering fossils, and particularly fossil hominins. Previous attempts at CT imaging of rocks from other South African sites for this purpose yielded disappointing results. For this study, 109 fossil- bearing rocks from the site of Malapa, South Africa were scanned with medical CT prior to manual preparation. The resultant images were assessed for accuracy of fossil identification and characterization against the standard of manual preparation. The accurate identification of fossils, including those of early hominins, that were not visible on the surface of individual blocks, is shown to be possible. The discovery of unexpected fossils is reduced, thus lowering the potential that fossils could be damaged through accidental encounter during routine preparation, or even entirely missed. This study should significantly change the way fossil discovery, recovery and preparation is done in the South African context and has potential for application in other palaeontological situations. Medical CT imaging is shown to be reliable, readily available, cost effective and accurate in finding fossils within matrix conglomerates. Improvements in CT equipment and in CT image quality are such that medical CT is now a viable imaging modality for this palaeontological application.

  5. Discovering Hominins - Application of Medical Computed Tomography (CT to Fossil-Bearing Rocks from the Site of Malapa, South Africa.

    Directory of Open Access Journals (Sweden)

    Jacqueline S Smilg

    Full Text Available In the South African context, computed tomography (CT has been used applied to individually prepared fossils and small rocks containing fossils, but has not been utilized on large breccia blocks as a means of discovering fossils, and particularly fossil hominins. Previous attempts at CT imaging of rocks from other South African sites for this purpose yielded disappointing results. For this study, 109 fossil- bearing rocks from the site of Malapa, South Africa were scanned with medical CT prior to manual preparation. The resultant images were assessed for accuracy of fossil identification and characterization against the standard of manual preparation. The accurate identification of fossils, including those of early hominins, that were not visible on the surface of individual blocks, is shown to be possible. The discovery of unexpected fossils is reduced, thus lowering the potential that fossils could be damaged through accidental encounter during routine preparation, or even entirely missed. This study should significantly change the way fossil discovery, recovery and preparation is done in the South African context and has potential for application in other palaeontological situations. Medical CT imaging is shown to be reliable, readily available, cost effective and accurate in finding fossils within matrix conglomerates. Improvements in CT equipment and in CT image quality are such that medical CT is now a viable imaging modality for this palaeontological application.

  6. Application and machine accuracy of a new frameless computed tomography-guided stereotactic brain biopsy system in dogs.

    Science.gov (United States)

    Taylor, Amanda R; Cohen, Noah D; Fletcher, Stephen; Griffin, John F; Levine, Jonathan M

    2013-01-01

    The purpose of this study was to describe application and machine accuracy for a new computed tomography (CT) guided, frameless, stereotactic brain biopsy system in dogs. Heads from ten canine cadavers were secured to a bite-plate with six attached fiducial markers and imaged using CT. Fiducialized CT images were imported into stereotactic software and spherical phantom lesions between 3.9 and 5.5 mm in diameter were created in six locations. Infrared cameras and reflective markers were used to register fiducials to the reconstructed image set. Coordinates in the X, Y, and Z planes were identified for each lesion center. Iohexol (1.5 μl of 240 mgI/ml) was injected into the center of each lesion and CT scans were repeated. Pre- and postinjection CT images for each cadaver were fused using the system software. Application accuracy was calculated using the center of each phantom lesion and the center of each injected contrast material location. Machine accuracy was calculated using a phantom with known distances between four fixed points in the X, Y, and Z planes. Mean application accuracy in the first 5 cadavers was 4.3 mm (95% confidence interval [CI] 2.9-4.3 mm) and in the second 5 cadavers was 2.9 mm (95% CI 2-3.9 mm). The more superficial lesions were targeted significantly less accurately than the deeper lesions (P = 0.0183). Median machine accuracy was 0.1 mm and the range was 0.1-0.2 mm. Findings supported use of the new biopsy system for canine brain lesions >3.9 mm in diameter. © 2013 Veterinary Radiology & Ultrasound.

  7. Localization of transverse-sigmoid sinus junction using preoperative 3D computed tomography: application in retrosigmoid craniotomy.

    Science.gov (United States)

    Xia, Lei; Zhang, Mingshan; Qu, Yanming; Ren, Ming; Wang, Haoran; Zhang, Hongwei; Yu, Chunjiang; Zhu, Mingwang; Li, Jianhua

    2012-10-01

    In retrosigmoid craniotomy, neurosurgeons usually depend on surface landmarks and their experience to evaluate the position of transverse-sigmoid sinus junction (TSSJ) and place an appropriate initial burr-hole, which is not accurate each time because of variability in different craniums. The authors introduce a simple procedure based on 3D computed tomography (CT) to localize the TSSJ in retrosigmoid craniotomy. Eighteen patients who underwent retrosigmoid craniotomy were analyzed. On the internal view of skull in 3D CT image, a simulative burr-hole was placed on the margin of transverse-sigmoid sinus groove junction. Then, on the external view of skull in 3D CT image, the center of the simulative burr-hole was marked and a coordinate system was established based on a line connected the digastric point and the asterion. Then the coordinate of the burr-hole's center was measured in this coordinate system. In operation, the burr-hole was placed according to the coordinate measured previously and craniotomy was performed. The margin of TSSJ was exposed in each case. No damage of venous sinus was encountered. Post-operative skull base CT demonstrated a good match between the actual and predicted burr-hole and bone defects only existed along the cut line. This simple method could help in localizing the TSSJ and avoiding the risk of sinus injury and reducing the bone defect. It is sufficiently precise for practical application at surgical planning.

  8. Duodenal diverticulitis. computed tomography findings

    International Nuclear Information System (INIS)

    Sanchez, E.; Martin, S.; Garcia, J.; Dominguez, A.

    2001-01-01

    Duodenal diverticular occur very frequently among the general public. However, duodenal diverticulitis is a very uncommon clinical entity, the diagnosis of which requires radiological studies since the clinical signs cam mimic a great number of disease processes with different treatments. We present a case of duodenal diverticulitis in which the diagnosis according to ultrasound and computed tomography (CT) studies was confirmed intraoperatively. We also review the few cases of this entity reported in the literature. The CT findings are highly suggestive of duodenal diverticulitis given their similarity to those associated with diverticulitis at other sites. (Author) 5 refs,

  9. Computed tomography of stress fracture

    International Nuclear Information System (INIS)

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-01-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic. (orig.)

  10. High speed computer assisted tomography

    International Nuclear Information System (INIS)

    Maydan, D.; Shepp, L.A.

    1980-01-01

    X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large x-ray tube having a circular anode (3) surrounds the patient area. A movable electron gun (8) orbits adjacent to the anode. The anode directs into the patient area xrays which are delimited into a fan beam by a pair of collimating rings (21). After passing through the patient, x-rays are detected by an array (22) of movable detectors. Detector subarrays (23) are synchronously movable out of the x-ray plane to permit the passage of the fan beam

  11. High speed computer assisted tomography

    International Nuclear Information System (INIS)

    Maydan, D.; Shepp, L.A.

    1980-01-01

    X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large X-ray tube having an annular anode surrounds the patient area. A movable electron gun orbits adjacent to the anode. The anode directs X-rays through the patient area towards an array of movable detectors. Detector subarrays are synchronously movable out of the X-ray plane to permit passage of the X-ray beam as it rotates within a plane in which the detector array is disposed. (author)

  12. Brain metastases: computed tomography assessment

    International Nuclear Information System (INIS)

    Gordillo, Victoria; Yagual, Glenda; Vinueza, Clayreth

    1998-01-01

    Intracranial metastatic tumor is relatively frequent in patients with cancer from other origin. Its location and type of metastasis varies in relation to its linage from the primary tumor. And the sequence goes from the most frequent: lung and breast cancer, melanoma, GU tract, leukemia, GI tract, head and neck tumor. Computed tomography findings are extremely varied and non specific, so there are no radiologic characteristics even from the primary tumor. We reviewed 29 TC studies in the Radiology department of ION-SOLCA, from patients with diagnosis of brain metastasis, our findings showed the great variability in the radio-diagnosis imaging. (The author)

  13. Computed Tomography in Forensic Medicine

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2015-01-01

    Modern diagnostic imagining techniques are gaining popularity in forensic medicine. Denmark has been involved in the development of this use of imaging techniques from the beginning. The Institute of Forensic Medicine at the University of Southern Denmark acquired a helical computed tomography (CT...... AND METHODS: This thesis investigated 900 forensic cases that were CT-scanned and autopsied at the Institute of Forensic Medicine, University of Southern Denmark, from 2006-2011. The scanner was a Siemens Somatom Spirit dual-slice CT-scanner with a Siemens Syngo MultiModality workstation. Contrast enhancement...

  14. Inter laboratory comparison on Computed Tomography for industrial applications in the slaughterhouses

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; Christensen, Lars Bager; Cantatore, Angela

    2014-01-01

    Application of CT scanning - CIA-CT”. In the comparison, 4 laboratories from 4 countries were involved, and CT scanned two synthetic phantoms, which were used instead of real pig carcasses. A phantom consists of several polymer components as Poly methyl methacrylate (PMMA), Polyethylene (PE) and Polyvinyl...

  15. Cone beam computed tomography in endodontic

    Energy Technology Data Exchange (ETDEWEB)

    Durack, Conor; Patel, Shanon, E-mail: conordurack1@hotmail.com [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  16. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science......, Technology and Innovation. The comparison aims to collect information about measurement performance in state-of the-art industrial CT (Computed Tomography) scanning. Since CT scanning has entered the field of manufacturing and coordinate metrology, evaluation of uncertainty of measurement with assessment...

  17. Early clinical applications for imaging at microscopic detail: microfocus computed tomography (micro-CT).

    Science.gov (United States)

    Hutchinson, J Ciaran; Shelmerdine, Susan C; Simcock, Ian C; Sebire, Neil J; Arthurs, Owen J

    2017-07-01

    Microfocus CT (micro-CT) has traditionally been used in industry and preclinical studies, although it may find new applicability in the routine clinical setting. It can provide high-resolution three-dimensional digital imaging data sets to the same level of detail as microscopic examination without the need for tissue dissection. Micro-CT is already enabling non-invasive detailed internal assessment of various tissue specimens, particularly in breast imaging and early gestational fetal autopsy, not previously possible from more conventional modalities such as MRI or CT. In this review, we discuss the technical aspects behind micro-CT image acquisition, how early work with small animal studies have informed our knowledge of human disease and the imaging performed so far on human tissue specimens. We conclude with potential future clinical applications of this novel and emerging technique.

  18. Development and applications of high energy industrial computed tomography in China

    International Nuclear Information System (INIS)

    Xiao, YongShun; Chen, Zhiqiang

    2016-01-01

    In recent years, China's rapid development of high-end equipment manufacturing industry in the high-speed railway, aircraft, carrier rocket, etc. brings the growing requirements of the high quality assurance of the product. The accelerator based high-energy X-ray Industrial CT has the advantages of strong penetrating power, high sensitivity defect detection and quantitative measurement with image visualization, can meet the needs of the large complicated structure inspection demands. This paper introduces the current research and development status of high energy industrial CT system in China. Research achievements by the Tsinghua University and the Granpect company are discussed, including the ICT system design, high-power LINAC accelerator X-ray source and high detection efficiency detector development, fast and accurate reconstruction algorithms research, etc. This paper also introduces the particularized NDT applications from dozens of industrial CT systems made by Granpect in China, including welding structure nondestructive testing, assembly quality inspection, reverse engineering, scientific research and other applications. Then the future development and application of high energy industrial CT is prospected.

  19. The application of three-dimensional reconstruction technology in industrial computed tomography

    International Nuclear Information System (INIS)

    Zhang Aidong; Sun Lingxia; Zhou Ying; Ye Yunchang

    2009-01-01

    It's an important research aspect in domestic ICT field, that the 3-D visualization of continuous ICT images reconstructed by 3-D reconstruction technology. The contour lines are joint by triangles in the course of 3-D reconstructions of the continuous equidistant ICT images. After the stereo images of the scanned objects are displayed, some special functions including inspections of the objects from different angles and orientations, nondestructive measurement of some 3-D parameters and so on will be carried out just by operating the computer. The inspectors can get more detailed structural information by the reconstructed images. So in this way the convenience and veracity of the non-detection have been promoted. (authors)

  20. Use of Micro-Computed Tomography for Dental Studies in Modern and Fossil Odontocetes: Potential Applications and Limitations

    Directory of Open Access Journals (Sweden)

    Carolina Loch

    2013-10-01

    Full Text Available Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins, providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such as metabolic or physiologic events. Micro-Computed Tomography (Micro-CT is a non-invasive and non-destructive technique that allows 3-dimensional study of mineralized tissues, such as human teeth, and their physical properties. Teeth from extant dolphins (Cetacea: Odontoceti and some fossil odontocetes were scanned in a Skyscan 1172 Micro-CT desktop system. X-rays were generated at 100 kV and 100 µA for extant samples, and at 80kV and 124 µA for fossils. 0.5 mm thick aluminum and copper filters were used in the beam. Reconstructed images were informative for most extant species, showing a good resolution of the enamel layer, dentine and pulp cavity. Greyscale changes in the dentinal layers were not resolved enough to show GLGs. Visualization of the internal structure in fossil cetacean teeth depended on the degree of diagenetic alteration in the specimen; undifferentiated enamel and dentine regions probably reflect secondary mineralization. However, internal details were finely resolved for one fossil specimen, showing the enamel, internal layers of dentine and the pulp cavity. Micro-CT has been proven to be a useful tool for resolving the internal morphology of fossil and extant teeth of cetaceans before they are sectioned for other morphological analyses; however some methodological refinements are still necessary to allow better resolution of dentine for potential application in non-destructive age determination studies.

  1. Dose determination in computed tomography

    International Nuclear Information System (INIS)

    Descamps, C.; Garrigo, E.; Venencia, D.; Gonzalez, M.; Germanier, A.

    2011-10-01

    In the last years the methodologies to determine the dose in computed tomography have been revised. In this work was realized a dosimetric study about the exploration protocols used for simulation of radiotherapy treatments. The methodology described in the Report No. 111 of the American Association of Medical Physiques on a computed tomograph of two cuts was applied. A cylindrical phantom of water was used with dimensions: 30 cm of diameter and 50 cm of longitude that simulates the absorption and dispersion conditions of a mature body of size average. The doses were determined with ionization chamber and thermoluminescent dosimetry. The results indicate that the dose information that provides the tomograph underestimates the dose between 32 and 35%.

  2. Dynamic computed tomography (CT) in the rat kidney and application to acute renal failure models

    International Nuclear Information System (INIS)

    Ishikawa, Isao; Saito, Tadashi; Ishii, Hirofumi; Bansho, Junichi; Koyama, Yukinori; Tobita, Akira

    1995-01-01

    Renal dynamic CT scanning is suitable for determining the excretion of contrast medium in the cortex and medulla of the kidney, which is valuable for understanding the pathogenesis of disease processes in various conditions. This form of scanning would be convenient for use, if a method of application to the rat kidney were available. Therefore, we developed a method of applying renal dynamic CT to rats and evaluated the cortical and medullary curves, e.g., the corticomedullary junction time which is correlated to creatinine clearance, in various rat models of acute renal failure. The rat was placed in a 10deg oblique position and a bilateral hilar slice was obtained before and 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160 and 180 sec after administering 0.5 ml of contrast medium using Somatom DR. The width of the slice was 4 mm and the scan time was 3 sec. The corticomedullary junction time in normal rats was 23.0±10.5 sec, the peak value of the cortical curve was 286.3±76.7 Hounsfield Unit (HU) and the peak value of the medullary curve was 390.1±66.2 HU. Corticomedullary junction time after exposure of the kidney was prolonged compared to that of the unexposed kidney. In rats with acute renal failure, the excretion pattern of contrast medium was similar in both the glycerol- and HgCl2-induced acute renal failure models. The peak values of the cortical curve were maintained three hours after a clamp was placed at the hilar region of the kidney for one hour, and the peak values of the medullary curve were maintained during the administration of 10μg/kg/min of angiotensin II. Dynamic CT curves in the acute renal failure models examined were slightly different from those in human acute renal failure. These results suggest that rats do not provide an ideal model for human acute renal failure. However, the application of dynamic CT to the rat kidney models was valuable for estimating the pathogenesis of various human kidney diseases. (author)

  3. Adaptive Computed Tomography Imaging Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The present proposal describes the development of an adaptive Computed Tomography Imaging Spectrometer (CTIS), or "Snapshot" spectrometer which can "instantaneously"...

  4. Overview of the Neutron Radiography and Computed Tomography at the Oak Ridge National Laboratory and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bilheux, Hassina Z [ORNL; Bilheux, Jean-Christophe [ORNL; Tremsin, Anton S [University of California, Berkeley; Santodonato, Louis J [ORNL; Dehoff, Ryan R [ORNL; Kirka, Michael M [ORNL; Bailey, William Barton [ORNL; Keener, Wylie S [ORNL; Herwig, Kenneth W [ORNL

    2015-01-01

    The Oak Ridge National Laboratory (ORNL) Neutron Sciences Directorate (NScD) has installed a neutron imaging (NI) beam line at the High Flux Isotope Reactor (HFIR) cold guide hall. The CG-1D beam line produces cold neutrons for a broad range of user research spanning from engineering to material research, additive manufacturing, vehicle technologies, archaeology, biology, and plant physiology. Recent efforts have focused on increasing flux and spatial resolution. A series of selected engineering applications is presented here. Historically and for more than four decades, neutron imaging (NI) facilities have been installed exclusively at continuous (i.e. reactor-based) neutron sources rather than at pulsed sources. This is mainly due to (1) the limited number of accelerator-based facilities and therefore the fierce competition for beam lines with neutron scattering instruments, (2) the limited flux available at accelerator-based neutron sources and finally, (3) the lack of high efficiency imaging detector technology capable of time-stamping pulsed neutrons with sufficient time resolution. Recently completed high flux pulsed proton-driven neutron sources such as the ORNL Spallation Neutron Source (SNS) at ORNL and the Japanese Spallation Neutron Source (JSNS) of the Japan Proton Accelerator Research Complex (J-PARC) in Japan produce high neutron fluxes that offer new and unique opportunities for NI techniques. Pulsed-based neutron imaging facilities RADEN and IMAT are currently being built at J-PARC and the Rutherford National Laboratory in the U.K., respectively. ORNL is building a pulsed neutron imaging beam line called VENUS to respond to the U.S. based scientific community. A team composed of engineers, scientists and designers has developed a conceptual design of the future VENUS imaging instrument at the SNS.

  5. Computed tomography of Krukenberg tumors

    International Nuclear Information System (INIS)

    Cho, K.C.; Gold, B.M.

    1985-01-01

    Computed tomography (CT) of three patients with Kurkenberg tumor was reviewed retrospectively. CT showed large, lobulated, multicystic masses with soft-tissue components, indistinguishable from primary ovarian carcinoma. Much has been written about metastatic ovarian tumor, but this is the first report in the radiologic literature about their CT features. The authors emphasize the importance of recognizing the ovary as a frequent site of metastases and the proper approach to this problem. In patients with a history of colon or gastric carcinoma, the mixed cystic and solid ovarian mass on CT should be regarded as metastatic tumor until proven otherwise. A careful search for gastrointestinal tract signs or symptoms should be done in any patient with a pelvic tumor. When CT is done for evaluation of ovarian tumor, the stomach and colon should be carefully evaluated, and the ovaries routinely examined in the preoperative CT staging of gastric or colon carcinoma

  6. Computed tomography in spinal osteoblastoma

    International Nuclear Information System (INIS)

    Torricelli, P.; Martinelli, P.; Boriani, S.; Ferraro, A.

    1986-01-01

    In order to stress the role of computed tomography (CT) in the evaluation of benign spinal osteoblastoma, the authors examined by CT 10 patients with surgically and histologically proved osteoblastomas of the spine. Basing on surgical and histopathological findings CT proved to be a very important method for attesting the presence of the tumors (usually showed by radiographic examination), and specially for their staging and follow-up. CT in fact showed the real extent of the tumor into the spinal canal and towards the paraspinal soft tissues, and allowed the aerly detection of post surgical relapses. The authors conclude that CT is a primary diagnostic modality for preoperative planning and follow-up of benign osteoblastoma

  7. Computed tomography of calcaneal fractures

    International Nuclear Information System (INIS)

    Heger, L.; Wulff, K.; Seddiqi, M.S.A.

    1985-01-01

    Computed tomography (CT) of 25 fractured calcanei was performed to investigate the potential of CT in evaluating the pattern and biomechanics of these fractures. The characteristic findings of typical fractures are presented, including the number and type of principal fragments, size and dislocation of the sustentacular fragment, and involvement of the anterior and posterior facets of the subtalar joint. In 17 cases, the calcaneus consisted of four or more fragments. Furthermore, in 17 cases the sustentacular fragment included all or part of the posterior facet joint. In 18 of the 25 cases, the sustentacular fragment was displaced. It is concluded that well performed CT is an invaluable adjunct in understanding the fracture mechanism and in detecting pain-provoking impingement between the fibular malleolus and the tuberosity fragment

  8. Computed tomography of calcaneal fractures

    Energy Technology Data Exchange (ETDEWEB)

    Heger, L.; Wulff, K.; Seddiqi, M.S.A.

    1985-07-01

    Computed tomography (CT) of 25 fractured calcanei was performed to investigate the potential of CT in evaluating the pattern and biomechanics of these fractures. The characteristic findings of typical fractures are presented, including the number and type of principal fragments, size and dislocation of the sustentacular fragment, and involvement of the anterior and posterior facets of the subtalar joint. In 17 cases, the calcaneus consisted of four or more fragments. Furthermore, in 17 cases the sustentacular fragment included all or part of the posterior facet joint. In 18 of the 25 cases, the sustentacular fragment was displaced. It is concluded that well performed CT is an invaluable adjunct in understanding the fracture mechanism and in detecting pain-provoking impingement between the fibular malleolus and the tuberosity fragment.

  9. Computed tomography in sport injuries

    International Nuclear Information System (INIS)

    Reiser, M.; Rupp, N.

    1984-01-01

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability. (orig.)

  10. Computed Tomography Scan and ICD Interaction

    Directory of Open Access Journals (Sweden)

    Jose M. Porres

    2009-01-01

    Full Text Available Although it has been considered a safe procedure, computed tomography scanning uses high doses of radiation and can cause malfunctioning in those patients with ICD when the radiation is directly incident on the device. We present a case of ventricular oversensing during a thoracic computed tomography.

  11. Appropriateness of computed tomography and magnetic resonance ...

    African Journals Online (AJOL)

    Appropriateness of computed tomography and magnetic resonance imaging scans in the Eden and Central Karoo districts of the Western Cape Province, South Africa. ... South African Medical Journal ... Computed tomography (CT) and magnetic resonance imaging (MRI) are an essential part of modern healthcare. Marked ...

  12. Physical characterization and performance evaluation of an x-ray micro-computed tomography system for dimensional metrology applications

    DEFF Research Database (Denmark)

    Hiller, Jochen; Maisl, Michael; Reindl, Leonard M

    2012-01-01

    components of a CT scanner, i.e. the x-ray tube and the flat-panel detector, are characterized. The contrast and noise transfer property of the scanner is obtained using image-processing methods based on linear systems theory. A long-term temperature measurement in the scanner cabinet has been carried out......This paper presents physical and metrological characterization measurements conducted for an industrial x-ray micro-computed tomography (CT) system. As is well known in CT metrology, many factors, e.g., in the scanning and reconstruction process, the image processing, and the 3D data evaluation...

  13. Application of X-ray computed micro-tomography to the study of damage and oxidation kinetics of thermostructural composites

    Energy Technology Data Exchange (ETDEWEB)

    Caty, Olivier, E-mail: caty@lcts.u-bordeaux1.fr [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France); Ibarroule, Philippe; Herbreteau, Mathieu; Rebillat, Francis [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France); Maire, Eric [MATEIS Laboratory, INSA Lyon, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Vignoles, Gérard L. [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France)

    2014-04-01

    Thermostructural composites are three-dimensionally (3D) structured materials. Weakening phenomena (mechanical and chemical) take place inside the material following its 3D structure and are thus hard to describe accurately. X-ray computed micro-tomography (μCT) is a recent solution that allows their experimental investigation. The technique is applied here to the study of failure under tensile loading and to the self healing processes during oxidation. Results are useful data to verify or invalidate hypotheses or estimations made in current models.

  14. Fused Entropy Algorithm in Optical Computed Tomography

    Directory of Open Access Journals (Sweden)

    Xiong Wan

    2014-02-01

    Full Text Available In most applications of optical computed tomography (OpCT, limited-view problems are often encountered, which can be solved to a certain extent with typical OpCT reconstructive algorithms. The concept of entropy first emerged in information theory has been introduced into OpCT algorithms, such as maximum entropy (ME algorithms and cross entropy (CE algorithms, which have demonstrated their superiority over traditional OpCT algorithms, yet have their own limitations. A fused entropy (FE algorithm, which follows an optimized criterion combining self-adaptively ME with CE, is proposed and investigated by comparisons with ME, CE and some traditional OpCT algorithms. Reconstructed results of several physical models show this FE algorithm has a good convergence and can achieve better precision than other algorithms, which verifies the feasibility of FE as an approach of optimizing computation, not only for OpCT, but also for other image processing applications.

  15. Cone beam computed tomography in Endodontics - a review.

    Science.gov (United States)

    Patel, S; Durack, C; Abella, F; Shemesh, H; Roig, M; Lemberg, K

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on the applications and limitations of CBCT; (ii) make recommendations for the use of CBCT in Endodontics; (iii) highlight areas of further research of CBCT in Endodontics. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  16. Analysis of the computed tomography in the acute abdomen

    International Nuclear Information System (INIS)

    Hochhegger, Bruno; Moraes, Everton; Haygert, Carlos Jesus Pereira; Antunes, Paulo Sergio Pase; Gazzoni, Fernando; Lopes, Luis Felipe Dias

    2007-01-01

    Introduction: This study tends to test the capacity of the computed tomography in assist in the diagnosis and the approach of the acute abdomen. Material and method: This is a longitudinal and prospective study, in which were analyzed the patients with the diagnosis of acute abdomen. There were obtained 105 cases of acute abdomen and after the application of the exclusions criteria were included 28 patients in the study. Results: Computed tomography changed the diagnostic hypothesis of the physicians in 50% of the cases (p 0.05), where 78.57% of the patients had surgical indication before computed tomography and 67.86% after computed tomography (p = 0.0546). The index of accurate diagnosis of computed tomography, when compared to the anatomopathologic examination and the final diagnosis, was observed in 82.14% of the cases (p = 0.013). When the analysis was done dividing the patients in surgical and nonsurgical group, were obtained an accuracy of 89.28% (p 0.0001). The difference of 7.2 days of hospitalization (p = 0.003) was obtained compared with the mean of the acute abdomen without use the computed tomography. Conclusion: The computed tomography is correlative with the anatomopathology and has great accuracy in the surgical indication, associated with the capacity of increase the confident index of the physicians, reduces the hospitalization time, reduces the number of surgeries and is cost-effective. (author)

  17. Errors in abdominal computed tomography

    International Nuclear Information System (INIS)

    Stephens, S.; Marting, I.; Dixon, A.K.

    1989-01-01

    Sixty-nine patients are presented in whom a substantial error was made on the initial abdominal computed tomography report. Certain features of these errors have been analysed. In 30 (43.5%) a lesion was simply not recognised (error of observation); in 39 (56.5%) the wrong conclusions were drawn about the nature of normal or abnormal structures (error of interpretation). The 39 errors of interpretation were more complex; in 7 patients an abnormal structure was noted but interpreted as normal, whereas in four a normal structure was thought to represent a lesion. Other interpretive errors included those where the wrong cause for a lesion had been ascribed (24 patients), and those where the abnormality was substantially under-reported (4 patients). Various features of these errors are presented and discussed. Errors were made just as often in relation to small and large lesions. Consultants made as many errors as senior registrar radiologists. It is like that dual reporting is the best method of avoiding such errors and, indeed, this is widely practised in our unit. (Author). 9 refs.; 5 figs.; 1 tab

  18. Cranial injuries and computer tomography

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    Patients, especially personal patients, with cerebral contusion and intracerebral hematoma were studied. Of 388 patients with cranial injuries who received computer tomography (CT) in our institute, 53 had cerebral contusion and 15 had intracerebral hematoma. CT revealed even hematoma at the parietal lobe or the inside of the cerebral hemispherium due to the cerebral contusion. The CT findings of cerebral contusion were classified into 3, that is, those with low density, those with high density, and those with non-homogenous density. From these findings cerebral edema rather than cerebral contusion was suspected. In patients with severe symptoms the basal cistern of the brain deformed and disappeared, frequently indicating that they had cerebral swellings. Only 20% of the patients with contusion at the brain-stem had abnormal CT findigns. Many patients with intracerebral hematoma complained headache, and these patients could be diagnosed easily by CT. In general it is believed that contrast enhancement is not necessary for patients with cranial injuries, but it was reported that 90% of patients with contusion showed enhancement after the use of contrast medium. (Ichikawa, K.)

  19. Computed Tomography of Interacerebral Hemorrhage

    International Nuclear Information System (INIS)

    Kim, Seung Hyeon; Lee, Jong Beum; Lee, Yong Chul; Lee, Kwan Seh; Park, Soo Soung

    1983-01-01

    Computed tomography (CT) is the most accurate and reliable method for the diagnosis of intracerebral and intraventricular hemorrhage. The precise anatomic extent of the nematoma, associated cerebral edema, ventricular deformity and displacement, and hydrocephalus are all readily assessed. Aside from head trauma, the principal cause of intracerebral hematoma is hypertensive vascular disease. Although hematomas from various causes may present similar CT appearances frequently the correct etiology may be suggested by consideration of patient's age, clinical history, and the location of the hematoma. The analytical study was performed in 180 cases of intracerebral hemorrhages by CT from October 1981 to January 1983. The results were as follows; 1. The most prevalent age group was 6th decade (37.2%). Male was prevalent to female at the ration of 1.6 to 1. 2. The most common symptom and sign was mental disturbance (48.7%), motor weakness (23%), headache (10.6%), nausea and vomiting (9.8%). 3. The causes of hemorrhage were hypertension (53.9%), head trauma (30.6%), aneurysm (6.1%) and A-V malformation (7.2%). 4. The frequent locations of hemorrhage were basal ganglia and thalamus (40.4%), lobes (35%), ventricles (21.8%). 5. The distribution of hemorrhage was intracerebral hemorrhage (65.6%), intracerebral and intraventricular hemorrhage (30.3%), intraventricular hemorrhage (4.4%).

  20. Clinical applications of cone beam computed tomography in endodontics: a comprehensive review. Part 1: applications associated with endodontic treatment and diagnosis

    NARCIS (Netherlands)

    Cohenca, N.; Shemesh, H.

    2015-01-01

    Cone beam computed tomography (CBCT) is a new technology that produces three-dimensional (3D) digital imaging at reduced cost and less radiation for the patient than traditional CT scans. It also delivers faster and easier image acquisition. By providing a 3D representation of the maxillofacial

  1. Clinical Application of Cone Beam Computed Tomography of the Rabbit Head: Part 2—Dental Disease

    Science.gov (United States)

    Riggs, G. G.; Cissell, Derek D.; Arzi, Boaz; Hatcher, David C.; Kass, Philip H.; Zhen, Amy; Verstraete, Frank J. M.

    2017-01-01

    Domestic rabbits are increasing in popularity as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental disease. Current diagnostic approaches include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). Cone beam computed tomography (CBCT), a new oral and maxillofacial imaging modality that has the capability to produce high-resolution images, has not yet been described for use in evaluating dental disease in rabbits. A total of 15 client-owned rabbits had CBCT, oral examination, dental charting, and dental treatment performed under general anesthesia. Images were evaluated using transverse and custom multiplanar (MPR), 3D, and panoramic reconstructed images. The CBCT findings were grouped into abnormalities that could be detected on conscious oral examination vs. abnormalities that could not be detected by conscious oral examination. Potential associations between the two categories were examined by pairwise Fisher’s exact test with statistical significance determined by P periapical lucency (11/15), moth-eaten pattern of osteolysis of the alveolar bone (9/15), ventral mandibular border contour changes (9/15), and missing teeth (8/15). Of the CBCT abnormalities likely to be observed on oral examination, coronal elongation (detectable on oral examination) was significantly associated with apical elongation (P = 0.029). There were no other significant associations between CBCT findings that are also clinically detectable and CBCT findings that are not be detectable on oral examination. This suggests that pathology often exists that is not apparent upon oral examination. This study establishes the common CBCT findings associated with dental disease in rabbits and demonstrates the feasibility of this technology to diagnose and plan treatment in dental disorders in this species. PMID:28194401

  2. Evaluation of computed tomography for obstructive jaundice

    International Nuclear Information System (INIS)

    Matsuoka, Shoji; Toda, Hiroshi; Suzuki, Toshihiko

    1980-01-01

    Findings of computed tomography were reviewed in 54 cases where obstructive jaundice was suggested by liver function studies and computed tomography was done with the diagnosis subsequently confirmed by surgery. Dilatation of the intrahepatic bile duct was found in 49 (91%) of the cases and the site of obstruction was determined in 44 cases (82%). The cause was shown in 28 cases (52%). By disease, the cause was correctly diagnosed with gallbladder in 40%, bile duct cancer in 46%, pancreas cancer in 71%, and choledocal cyst in 100%, but cholelithiasis was diagnosed correctly in only 17%. Further, non-calcium cholelithiasis is very difficult to diagnose by computed tomography. Computed tomography is a useful tool for diagnosis of obstructive jaundice as a noninvasive means of evaluating the patient; however, concomitand use of other diagnostic studies is essential for greater accuracy of diagnosis. (author)

  3. Bladder hernia: Multidetector computed tomography findings

    Directory of Open Access Journals (Sweden)

    Ankur Gadodia

    2011-01-01

    Full Text Available Herniation of bladder in inguinal hernia is rare, with most cases diagnosed intraoperatively. Preoperative diagnosis is even rarer. We report a case of bladder as content of inguinal hernia diagnosed using multidetector computed tomography.

  4. Quantitative computed tomography evaluation of pulmonary disease

    DEFF Research Database (Denmark)

    McEvoy, Fintan; Buelund, Lene Elisabeth; Strathe, Anders Bjerring

    2009-01-01

    Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present....

  5. Examination of weld defects by computed tomography

    Directory of Open Access Journals (Sweden)

    M. Jovanović

    2012-04-01

    Full Text Available Defects in metal arc gas (MAG welds made in S235JR low carbon steel of 6 mm thickness were examined. A sample containing lack of fusion (LOF and pores was examined by computed tomography – CT. The computed tomography examination was performed in order to define LOF size and position as well as dimensions and distribution of accompanying pores in the weld metal.

  6. Dose optimization in computed tomography: ICRP 87

    International Nuclear Information System (INIS)

    2007-01-01

    The doses given in the use of computed tomography scans are studied, aiming to calibrate the limits of irradiation in patients who need these tests. Furthermore, a good value of computed tomography should be guaranteed by physicians and radiologists for people not being irradiated unfairly, reducing doses and unnecessary tests. A critical evaluation by an ethics committee is suggested for cases where the test is performed for medical research without a cause [es

  7. Computed tomography in abnormalities of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Visser, J.D.; Jonkers, A.; Klasen, H.J. (Rijksuniversiteit Groningen (Netherlands). Academisch Ziekenhuis); Hillen, B. (Rijksuniversiteit Groningen (Netherlands). Lab. voor Anatomie en Embryologie)

    1982-06-26

    The value of computed tomography in the assessment of abnormalities of the hip is demonstrated with the aid of an anatomical preparation and in patients with, respectively, congenital dislocation of a hip, dislocation of the hip in spina bifida, an acetabular fracture and a Ewing tumour. The anteversion of the acetabulum and femur and the instability index of the hip joint can be measured by means of computed tomography.

  8. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  9. Positron emission tomography/computed tomography scanning for ...

    African Journals Online (AJOL)

    Background: Although the site of nosocomial sepsis in the critically ill ventilated patient is usually identifiable, it may remain occult, despite numerous investigations. The rapid results and precise anatomical location of the septic source using positron emission tomography (PET) scanning, in combination with computed ...

  10. Computed Tomography in the Modern Slaughterhouse

    DEFF Research Database (Denmark)

    Mosbech, Thomas Hammershaimb

    of technology. Recently, the use of X-ray computed tomography (CT) coupled with methods from image analysis has been introduced as a powerful means to optimise production, by providing detailed information on the raw materials. This thesis covers two aspects of the application of CT in the modern abattoir......The Danish pig meat industry has been seeing a growing international competition in the past years. In the quest to maintain both competitive prices and high product standards in spite of the higher Danish factor costs, a substantial effort is being put into innovation, research and development...... the yield of the Danish pig meat industry. An introduction of efficient online CT will especially open a vast number of possibilities for optimising the production....

  11. Practical techniques for pediatric computed tomography

    International Nuclear Information System (INIS)

    Fitz, C.R.; Harwood-Nash, D.C.; Kirks, D.R.; Kaufman, R.A.; Berger, P.E.; Kuhn, J.P.; Siegel, M.J.

    1983-01-01

    Dr. Donald Kirks has assembled this section on Practical Techniques for Pediatric Computed Tomography. The material is based on a presentation in the Special Interest session at the 25th Annual Meeting of the Society for Pediatric Radiology in New Orleans, Louisiana, USA in 1982. Meticulous attention to detail and technique is required to ensure an optimal CT examination. CT techniques specifically applicable to infants and children have not been disseminated in the radiology literature and in this respect it may rightly be observed that ''the child is not a small adult''. What follows is a ''cookbook'' prepared by seven participants and it is printed in Pediatric Radiology, in outline form, as a statement of individual preferences for pediatric CT techniques. This outline gives concise explanation of techniques and permits prompt dissemination of information. (orig.)

  12. Neutron stimulated emission computed tomography: Background corrections

    International Nuclear Information System (INIS)

    Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

    2007-01-01

    Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

  13. Clinical utility of dental cone-beam computed tomography: current perspectives

    Directory of Open Access Journals (Sweden)

    Jaju PP

    2014-04-01

    Full Text Available Prashant P Jaju,1 Sushma P Jaju21Oral Medicine and Radiology, 2Conservative Dentistry and Endodontics, Rishiraj College of Dental Sciences and Research Center, Bhopal, IndiaAbstract: Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology and forensic dentistry, and its limitations in maxillofacial diagnosis.Keywords: dental implants, cone-beam computed tomography, panoramic radiography, computed tomography

  14. Application of a newly developed software program for image quality assessment in cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    De Oliveira, Marcus Vinicius Linhares; Campos, Paulo Sergio Flores [Federal Institute of Bahia, Salvador (Brazil); Paulo, Graciano; Santos, Antonio Carvalho; Santos, Joana [Coimbra Health School, Polytechnic Institute of Coimbra, Coimbra (Portugal)

    2017-06-15

    The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ImageJ, to automatically evaluate the image quality parameters. The image quality evaluation was based on 8 parameters: uniformity, the signal-to-noise ratio (SNR), noise, the contrast-to-noise ratio (CNR), spatial resolution, the artifact index, geometric accuracy, and low-contrast resolution. The image uniformity and noise depended on the protocol that was applied. Regarding the CNR, high-density structures were more sensitive to the effect of scanning parameters. There were no significant differences between SNR and CNR in centered and peripheral objects. The geometric accuracy assessment showed that all the distance measurements were lower than the real values. Low-contrast resolution was influenced by the scanning parameters, and the 1-mm rod present in the phantom was not depicted in any of the 3 CBCT units. Smaller voxel sizes presented higher spatial resolution. There were no significant differences among the protocols regarding artifact presence. This software package provided a fast, low-cost, and feasible method for the evaluation of image quality parameters in CBCT.

  15. Synthesis of nanostructured barium phosphate and its application in micro-computed tomography of mouse brain vessels in ex vivo

    Science.gov (United States)

    Zhu, Bangshang; Yuan, Falei; Yuan, Xiaoya; Bo, Yang; Wang, Yongting; Yang, Guo-Yuan; Drummen, Gregor P. C.; Zhu, Xinyuan

    2014-02-01

    Micro-computed tomography (micro-CT) is a powerful tool for visualizing the vascular systems of tissues, organs, or entire small animals. Vascular contrast agents play a vital role in micro-CT imaging in order to obtain clear and high-quality images. In this study, a new kind of nanostructured barium phosphate was fabricated and used as a contrast agent for ex vivo micro-CT imaging of blood vessels in the mouse brain. Nanostructured barium phosphate was synthesized through a simple wet precipitation method using Ba(NO3)2, and (NH4)2HPO4 as starting materials. The physiochemical properties of barium phosphate were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermal analysis. Furthermore, the impact of the produced nanostructures on cell viability was evaluated via the MTT assay, which generally showed low to moderate cytotoxicity. Finally, the animal test images demonstrated that the use of nanostructured barium phosphate as a contrast agent in Micro-CT imaging produced sharp images with excellent contrast. Both major vessels and the microvasculature were clearly observable in the imaged mouse brain. Overall, the results indicate that nanostructured barium phosphate is a potential and useful vascular contrast agent for micro-CT imaging.

  16. Application of the axial tomography computed for the detection of bags of dampness in dry wood of Gmelina arborea (Roxb.)

    International Nuclear Information System (INIS)

    Moya R, Roger; Munoz A, Freddy; Escalante, Ivan

    2006-01-01

    Gmelina arborea (Roxb.) is widely used for commercial reforestation in Costa Rica due to its excellent growth rate and productivity. However, during the lumber drying process, the wooden boards show non-uniform values of final moisture content (MC). The low uniformity in final MC is caused by the presence of wet pockets, originated during the growing process of the tree. The regions with wet pockets present zones with a high MC, which are hard to detect with traditional methods for MC measurements during the wood drying process. It is possible to detect and to set the limits of the presence of wet wood in Gmelina arborea boards using scanning computed tomography (CT-scanning), a technique applied in medical diagnostic. A board with wet pockets is shown in the CT-scanning images in clear color and with low values of the Hounsfield Unit (HU) or CT number. When these values were transformed to wood density, it was determined that wet pockets were in a density of around 190 kg/m 3 , a value higher than normal wood. Also, it was possible to observe growth tree rings in the CT-scanning images, an important feature for dendrochronological research. The obtained results allowed showing that it is possible to apply this technique in the process of lumber production, to detect the zones with high MC in kiln dried Gmelina arborea wood. (author) [es

  17. Application of X-Ray Computed Tomography for Analyzing Cleats and Pores for Coalbed Methane in Coal from Thar Coalfield

    Directory of Open Access Journals (Sweden)

    Imdadullah Siddiqui

    2014-04-01

    Full Text Available The CT (Computed Tomography is a non-destructive technique that can provide information of internal structure of coal in two-dimensional, this technology is now widely used in geoscientific research. This technique is used for the measuring cleat dimension and pore width of the Thar coal. The slicing study of Thar coal shows that the length of cleats in various seams ranges from 0.5-5mm and the aperture of these cleats vary between 0.1-0.5mm. The porosity also plays an important role in storage and production of coalbed methane, the size or width of pores in coal under investigation ranges between 0.1-0.7mm. The present investigation shows that Seam-III and V of the can be considered as viable as hold a potential for CBM (Coalbed Methane resources, however, the coal samples from these seams need to be analyzed for the presence of methane In Thar coalfield, the pore volume ranges from 0.06-2.36 cc/g and pore diameter in Thar coal ranges from meso-pore and macro-pore (34.81-121.51Å. These meso and macro-pores serve as transport pathways, and little methane is stored in these pores in the adsorbed state

  18. Application of a newly developed software program for image quality assessment in cone-beam computed tomography

    International Nuclear Information System (INIS)

    De Oliveira, Marcus Vinicius Linhares; Campos, Paulo Sergio Flores; Paulo, Graciano; Santos, Antonio Carvalho; Santos, Joana

    2017-01-01

    The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ImageJ, to automatically evaluate the image quality parameters. The image quality evaluation was based on 8 parameters: uniformity, the signal-to-noise ratio (SNR), noise, the contrast-to-noise ratio (CNR), spatial resolution, the artifact index, geometric accuracy, and low-contrast resolution. The image uniformity and noise depended on the protocol that was applied. Regarding the CNR, high-density structures were more sensitive to the effect of scanning parameters. There were no significant differences between SNR and CNR in centered and peripheral objects. The geometric accuracy assessment showed that all the distance measurements were lower than the real values. Low-contrast resolution was influenced by the scanning parameters, and the 1-mm rod present in the phantom was not depicted in any of the 3 CBCT units. Smaller voxel sizes presented higher spatial resolution. There were no significant differences among the protocols regarding artifact presence. This software package provided a fast, low-cost, and feasible method for the evaluation of image quality parameters in CBCT

  19. Application of γ-ray computed tomography to evaluate the radius of influence of soil solution extractors and tensiometers

    International Nuclear Information System (INIS)

    Pires, Luiz F.; Arthur, Robson C.J.; Bacchi, Osny O.S.; Reichardt, Klaus

    2007-01-01

    Tensiometers and soil solution extractors are tools commonly used in irrigated agriculture and in studies of soil solute movement. The matric potential (Ψ m ) measured through tensiometers represents the energy by which water is retained by soil matrix. A relevant aspect that has to be taken into account while evaluating any instrument based on the use of sensors, like the porous cup of tensiometers, is the interference of the sensor on the property that is being measured. Information related to the range of influence of the sensor, its response power and its operation become very important when one is looking for precise results. The objective of this study was to evaluate the region of influence of tensiometer and solution extractor porous cups used in soil physical measurements. A first-generation γ-ray scanner was used having a 241 Am γ-ray source and a 7.62 x 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube. Image analysis and tomographic unit distributions could successfully be used for visualizing soil water content changes around the porous cup and for verifying its range of influence. The results show that computed tomography technique is a valuable tool because it makes it possible to provide an insight about the soil water content spatial distributions around the porous cup of tensiometers and solution extractors. The way that soil water content and matric potential are affected by these sensors was shown by this study

  20. Application of a newly developed software program for image quality assessment in cone-beam computed tomography.

    Science.gov (United States)

    de Oliveira, Marcus Vinicius Linhares; Santos, António Carvalho; Paulo, Graciano; Campos, Paulo Sergio Flores; Santos, Joana

    2017-06-01

    The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ImageJ, to automatically evaluate the image quality parameters. The image quality evaluation was based on 8 parameters: uniformity, the signal-to-noise ratio (SNR), noise, the contrast-to-noise ratio (CNR), spatial resolution, the artifact index, geometric accuracy, and low-contrast resolution. The image uniformity and noise depended on the protocol that was applied. Regarding the CNR, high-density structures were more sensitive to the effect of scanning parameters. There were no significant differences between SNR and CNR in centered and peripheral objects. The geometric accuracy assessment showed that all the distance measurements were lower than the real values. Low-contrast resolution was influenced by the scanning parameters, and the 1-mm rod present in the phantom was not depicted in any of the 3 CBCT units. Smaller voxel sizes presented higher spatial resolution. There were no significant differences among the protocols regarding artifact presence. This software package provided a fast, low-cost, and feasible method for the evaluation of image quality parameters in CBCT.

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  2. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which rotates around the patient. The computer that processes the imaging information and monitor are located in ... follows a spiral path. A special computer program processes this series of pictures, or slices of the ...

  3. The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in resectable pancreatic cancer.

    Science.gov (United States)

    Crippa, Stefano; Salgarello, Matteo; Laiti, Silvia; Partelli, Stefano; Castelli, Paola; Spinelli, Antonello E; Tamburrino, Domenico; Zamboni, Giuseppe; Falconi, Massimo

    2014-08-01

    The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in pancreatic ductal adenocarcinoma is debated. We retrospectively assessed the value of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in addition to conventional imaging as a staging modality in pancreatic cancer. (18)Fluoro-deoxyglucose positron emission tomography/computed tomography was performed in 72 patients with resectable pancreatic carcinoma after multi-detector computed tomography positron emission tomography was considered positive for a maximum standardized uptake value >3. Overall, 21% of patients had a maximum standardized uptake value ≤ 3, and 60% of those had undergone neoadjuvant treatment (P=0.0001). Furthermore, 11% of patients were spared unwarranted surgery since positron emission tomography/computed tomography detected metastatic disease. All liver metastases were subsequently identified with contrast-enhanced ultrasound. Sensitivity and specificity of positron emission tomography/computed tomography for distant metastases were 78% and 100%. The median CA19.9 concentration was 48.8 U/mL for the entire cohort and 292 U/mL for metastatic patients (P=0.112). The widespread application of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in patients with resectable pancreatic carcinoma seems not justified. It should be considered in selected patients at higher risk of metastatic disease (i.e. CA19.9>200 U/mL) after undergoing other imaging tests. Neoadjuvant treatment is significantly associated with low metabolic activity, limiting the value of positron emission tomography in this setting. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  4. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    Science.gov (United States)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-09-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 × 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver ( p fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  5. Clinical Application of Cone-Beam Computed Tomography of the Rabbit Head: Part 1 – Normal Dentition

    Science.gov (United States)

    Riggs, G. G.; Arzi, Boaz; Cissell, Derek D.; Hatcher, David C.; Kass, Philip H.; Zhen, Amy; Verstraete, Frank J. M.

    2016-01-01

    Domestic rabbits (Oryctolagus cuniculus) are increasingly popular as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental diseases. Diagnostic approaches for dental disease include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). CT overcomes many limitations of standard radiography by permitting cross-sectional images of the rabbit head in multiple planes without superimposition of anatomic structures. Cone-beam CT (CBCT) is an oral and maxillofacial imaging modality that produces high-resolution images. The objective of this study was to describe and compare the normal anatomic features of the dentition and surrounding maxillofacial structures in healthy rabbits on CBCT and conventional CT. Ten New Zealand white rabbit cadaver heads were scanned using CBCT and conventional CT. Images were evaluated using Anatomage Invivo 5 software. The maxillofacial anatomy was labeled on CBCT images, and the mean lengths and widths of the teeth were determined. The visibility of relevant dental and anatomic features (pulp cavity, germinal center, tooth outline, periodontal ligament) were scored and compared between conventional CT and CBCT. The thinnest teeth were the maxillary second incisor teeth at 1.29 ± 0.26 mm and the maxillary third molar teeth at 1.04 ± 0.10 mm. In general, it was found that CBCT was superior to conventional CT when imaging the dentition. Importantly, the periodontal ligament was significantly (P < 0.01) more visible on CBCT than on conventional CT. Ability to see the periodontal ligament with such detail may allow earlier detection and treatment of periodontal disease in rabbits. This study is the first of its kind and shows the feasibility and yield of CBCT when evaluating the maxillofacial features and dentition in rabbits. PMID:27800485

  6. Indication for dental computed tomography. Case reports

    International Nuclear Information System (INIS)

    Schom, C.; Engelke, W.; Kopka, L.; Fischer, U.; Grabbe, E.

    1996-01-01

    Based on case reports, common indications for dental computed tomography are demonstrated and typical findings are analysed. From a group of 110 patients who had a reformatted computed tomography of the maxilla and mandibula, 10 typical cases were chosen as examples and are presented with a detailed description of the findings. The most important indication was the analysis of the morphology of the alveolar ridge needed in presurgical planning for osseointegrated implants as well as in special cases of postsurgical control. Apart from implantology, the method could be used in cases of mandibular cysts and bony destructions. In conclusion, dental computed tomography has become established mainly in implantology. It can provide valuable results in cases where a demonstration of the bone in all dimensions and free of overlappings and distortions is needed. (orig.) [de

  7. Computed tomography of oesophageal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Muehling, T.; Kuklinski, M.E.; Huebsch, T.; Witte, J.

    1985-08-01

    Between March, 1980 and January, 1984, computerized tomography (CT) was performed on 110 patients with proven esophageal carcinoma. In 26 patients, information obtained preoperatively by CT was compared with results of intraoperative exploration or histologic examination of resection specimen. Correlation analysis showed that accuracy of CT in assessing actual tumor size and mediastinal or abdominal lymphnode involvement is rather limited, while correct results were obtained in between 84 and 100 percent of patients as far as identification of invasion of adjacent organs is concerned. We thus advocate routine use of CT in the process of preoperative assessment of operability and staging.

  8. The Western Denmark Cardiac Computed Tomography Registry

    DEFF Research Database (Denmark)

    Nielsen, Lene Hüche; Nørgaard, Bjarne Linde; Tilsted, Hans-Henrik

    2015-01-01

    BACKGROUND: As a subregistry to the Western Denmark Heart Registry (WDHR), the Western Denmark Cardiac Computed Tomography Registry (WDHR-CCTR) is a clinical database established in 2008 to monitor and improve the quality of cardiac computed tomography (CT) in Western Denmark. OBJECTIVE: We...... positive and negative predictive values for both university (96%/99%) and nonuniversity centers (97%/99%). CONCLUSION: WDHR-CCTR provides ongoing prospective registration of all cardiac CTs performed in Western Denmark since 2008. Overall, the registry data have a high degree of completeness and validity...

  9. Epiploic appendicitis - ultrasonography and computed tomography findings

    International Nuclear Information System (INIS)

    Melo, Alessandro Severo Alves de; Alves, Jose Ricardo Duarte; . E-mail: lubiamoreira@bol.com.br; Moreira, Luiza Beatriz Melo; Pinheiro, Ricardo Andrade; Noro, Fabio; )

    2002-01-01

    Epiploic appendicitis is an uncommon inflammatory condition, which is presently better diagnosed by current imaging methods such as computed tomography and ultrasonography that allow a non-invasive and efficient diagnostic approach. The author studied 6 patients with epiploic appendicitis. The patients were submitted to computed tomography that showed paracolic oval lesions of 1 to 2 cm of diameter, fat attenuation and a thin peripheral hyperdense rim associated with adjacent fat stranding. Ultrasound examination performed in two patients showed hyperechoic ovoid noncompressible masses at the site of maximum abdominal tenderness. (author)

  10. Computed tomography in malignant primary bone tumours

    International Nuclear Information System (INIS)

    Kersjes, W.; Harder, T.; Haeffner, P.

    1990-01-01

    The importance of computed tomography is examined in malignant primary bone tumours using a strongly defined examination group of 13 Patients (six Ewing's-sarcomas, five osteosarcomas, one chondrosarcoma and one spindle-shaped cell sarcoma). Computed tomography is judged superior compared to plain radiographs in recognition of bone marrow infiltration and presentation of parosteal tumour parts as well as in analysis of tissue components of tumours, CT is especially suitable for therapy planning and evaluating response to therapy. CT does not provide sufficient diagnostic information to determine dignity and exact diagnosis of bone tumours. (orig.) [de

  11. Computed tomography of sacro-iliac joints

    International Nuclear Information System (INIS)

    Miquel, A.; Laredo, J.D.

    1995-01-01

    Actual technologies to explore sacro-iliac joints are conventional radiography, computed tomography , scintigraphy and nuclear magnetic resonance imaging. Standards films are sufficient, except in beginning sacro-iliac septic inflammations where the computed tomography is superior. Two problems are generally posed for the radiologist, to differentiate a septic arthritis from a rheumatic pathology An other problem in diagnosis is to make the difference between a degenerative arthropathy (which does not need a further investigation) and an infectious rheumatic pathology where more exploration is necessary. 28 refs., 3 tabs., 13 figs

  12. Radiation dosimetry of computed tomography x-ray scanners

    International Nuclear Information System (INIS)

    Poletti, J.L.; Williamson, B.D.P.; Le Heron, J.C.

    1983-01-01

    This report describes the development and application of the methods employed in National Radiation Laboratory (NRL) surveys of computed tomography x-ray scanners (CT scanners). It includes descriptions of the phantoms and equipment used, discussion of the various dose parameters measured, the principles of the various dosimetry systems employed and some indication of the doses to occupationally exposed personnel

  13. Computed tomography and childhood seizure disorder in Ibadan ...

    African Journals Online (AJOL)

    Background: Computed Tomography (CT) is an important tool for neuroimaging, it offers an opportunity to investigate structural lesions as a cause of seizures with little morbidity. This study is designed to evaluate it's applicability in children with epileptic seizures. Method: It is a descriptive study of the CT scans of the 103 ...

  14. Introduction to the foundations of X-ray computed tomography

    International Nuclear Information System (INIS)

    Herman, G.T.

    1979-01-01

    The author gives a brief survey of a small fraction of the existing literature on the foundations of X-ray computed tomography. While the selection is biased by the interests of the author, taken in conjunction with the other articles in this book, it should provide the means for getting acquainted with this very active field of applicable research. (Auth.)

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... through the body, recording an image on photographic film or a special image recording plate . Bones appear ...

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices ...

  18. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which are then displayed on a monitor. Special software can also generate three-dimensional (3-D) images ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ...

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  20. Motion-map constrained image reconstruction (MCIR): Application to four-dimensional cone-beam computed tomography

    International Nuclear Information System (INIS)

    Park, Justin C.; Kim, Jin Sung; Park, Sung Ho; Liu, Zhaowei; Song, Bongyong; Song, William Y.

    2013-01-01

    Purpose: Utilization of respiratory correlated four-dimensional cone-beam computed tomography (4DCBCT) has enabled verification of internal target motion and volume immediately prior to treatment. However, with current standard CBCT scan, 4DCBCT poses challenge for reconstruction due to the fact that multiple phase binning leads to insufficient number of projection data to reconstruct and thus cause streaking artifacts. The purpose of this study is to develop a novel 4DCBCT reconstruction algorithm framework called motion-map constrained image reconstruction (MCIR), that allows reconstruction of high quality and high phase resolution 4DCBCT images with no more than the imaging dose as well as projections used in a standard free breathing 3DCBCT (FB-3DCBCT) scan.Methods: The unknown 4DCBCT volume at each phase was mathematically modeled as a combination of FB-3DCBCT and phase-specific update vector which has an associated motion-map matrix. The motion-map matrix, which is the key innovation of the MCIR algorithm, was defined as the matrix that distinguishes voxels that are moving from stationary ones. This 4DCBCT model was then reconstructed with compressed sensing (CS) reconstruction framework such that the voxels with high motion would be aggressively updated by the phase-wise sorted projections and the voxels with less motion would be minimally updated to preserve the FB-3DCBCT. To evaluate the performance of our proposed MCIR algorithm, we evaluated both numerical phantoms and a lung cancer patient. The results were then compared with the (1) clinical FB-3DCBCT reconstructed using the FDK, (2) 4DCBCT reconstructed using the FDK, and (3) 4DCBCT reconstructed using the well-known prior image constrained compressed sensing (PICCS).Results: Examination of the MCIR algorithm showed that high phase-resolved 4DCBCT with sets of up to 20 phases using a typical FB-3DCBCT scan could be reconstructed without compromising the image quality. Moreover, in comparison with

  1. Motion-map constrained image reconstruction (MCIR): Application to four-dimensional cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Justin C. [Center for Advanced Radiotherapy Technologies and Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California 92093 and Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093 (United States); Kim, Jin Sung [Department of Radiation Oncology, Samsung Medical Center, Seoul 135-710 (Korea, Republic of); Park, Sung Ho [Department of Medical Physics, Asan Medical Center, College of Medicine, University of Ulsan, Seoul 138-736 (Korea, Republic of); Liu, Zhaowei [Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093 (United States); Song, Bongyong; Song, William Y. [Center for Advanced Radiotherapy Technologies and Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California 92093 (United States)

    2013-12-15

    Purpose: Utilization of respiratory correlated four-dimensional cone-beam computed tomography (4DCBCT) has enabled verification of internal target motion and volume immediately prior to treatment. However, with current standard CBCT scan, 4DCBCT poses challenge for reconstruction due to the fact that multiple phase binning leads to insufficient number of projection data to reconstruct and thus cause streaking artifacts. The purpose of this study is to develop a novel 4DCBCT reconstruction algorithm framework called motion-map constrained image reconstruction (MCIR), that allows reconstruction of high quality and high phase resolution 4DCBCT images with no more than the imaging dose as well as projections used in a standard free breathing 3DCBCT (FB-3DCBCT) scan.Methods: The unknown 4DCBCT volume at each phase was mathematically modeled as a combination of FB-3DCBCT and phase-specific update vector which has an associated motion-map matrix. The motion-map matrix, which is the key innovation of the MCIR algorithm, was defined as the matrix that distinguishes voxels that are moving from stationary ones. This 4DCBCT model was then reconstructed with compressed sensing (CS) reconstruction framework such that the voxels with high motion would be aggressively updated by the phase-wise sorted projections and the voxels with less motion would be minimally updated to preserve the FB-3DCBCT. To evaluate the performance of our proposed MCIR algorithm, we evaluated both numerical phantoms and a lung cancer patient. The results were then compared with the (1) clinical FB-3DCBCT reconstructed using the FDK, (2) 4DCBCT reconstructed using the FDK, and (3) 4DCBCT reconstructed using the well-known prior image constrained compressed sensing (PICCS).Results: Examination of the MCIR algorithm showed that high phase-resolved 4DCBCT with sets of up to 20 phases using a typical FB-3DCBCT scan could be reconstructed without compromising the image quality. Moreover, in comparison with

  2. [Preliminary application of kilo-volt cone-beam computed tomography to intensity-modulated radiotherapy of nasopharyngeal carcinoma].

    Science.gov (United States)

    Wang, Jin; Xu, Feng; Bai, Sen; Zhang, Hong; Zhong, Ren-Ming; Li, Yan; Li, Xiao-Yu

    2008-07-01

    The intensity-modulated radiotherapy (IMRT) with its highly conformed dose distribution to nasopharyngeal cancer (NPC) and the surrounding critical organs is being accepted increasingly in clinical practice. Due to the steep dose fall-offs of IMRT at the target margin, precise patient positioning and verification are required. This study was to evaluate the role of kilo-volt cone-beam computed tomography (kV-CBCT) in guiding the accurate positioning of IMRT for NPC. kV-CBCT was performed on 22 NPC patients before radiotherapy. The acquired CBCT were co-registered with the planning CT for online set-up correction and offline planning target volume (PTV) analysis. The 22 patients received a total of 754 kV-CBCT scans. Among the 505 scans before couch correction, the detection rates of deviation of < or =2 mm were 76.4% in left-to-right (X) direction, 76.0% in superior-to-inferior (Y) direction, and 85.7% in anterior-to-posterior (Z) directionû among the 106 scans after correction, the detection rates were 97.2%, 97.2%, and 100% in X, Y and Z directions, respectivelyû among the 143 scans after treatment, the detection rates were 87.4%, 87.6%, and 90.0%, respectively. The overall setup errors in X, Y and Z directions were (-0.7+/-1.6) mm, (-0.7+/-1.8) mm and (-0.3+/-1.7) mm, respectively, before correctionû (-0.4+/-0.8) mm, (0.3+/-0.8) mm and (0.0+/-0.7) mm, respectively, after correctionû (0.2+/-1.2) mm, (0.3+/-1.3) mm and (0.1+/-1.1) mm, respectively, after treatment. The maximal PTV margin was 4.0 mm before correction and 2.1 mm after correction. kV-CBCT image-guided radiotherapy may improve the set-up precision of IMRT for NPC.

  3. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    International Nuclear Information System (INIS)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-01-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 x 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver (p < 0.05). Furthermore, the F-value, which was used as a scale for the difference in recognition rates, was highest in the average gray level, relatively high in the skewness and the entropy, and relatively low in the uniformity, the relative smoothness and the average contrast. The recognition rate for a fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  4. Cone beam computed tomography in veterinary dentistry.

    Science.gov (United States)

    Van Thielen, Bert; Siguenza, Francis; Hassan, Bassam

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstructions were created using specialized software. Image quality and visibility of anatomical landmarks were subjectively assessed by two observers. Good image quality was obtained for the MPR para-sagittal reconstructions through multiple teeth. The image quality of the panoramic reconstructions of dogs was moderate while the panoramic reconstructions of cats were poor since the images were associated with an increased noise level. Segmental panoramic reconstructions of the mouth seem to be useful for studying the dental anatomy especially in dogs. The results of this study using human dental CBCT technology demonstrate the potential of this scanning technology in veterinary medicine. Unfortunately, the moderate image quality obtained with the CBCT technique reported here seems to be inferior to the diagnostic image quality obtained from 2-dimensional dental radiographs. Further research is required to optimize scanning and reconstruction protocols for veterinary applications.

  5. Computed tomography (CT) and diastematomyelia's diagnosis

    International Nuclear Information System (INIS)

    Santos, M.B. dos; Luca, V. de; Ferreira, M.A.S.; Barros, A.P. de

    1982-01-01

    After a case of diastematomyelia observed at the University Hospital (Federal University of Rio de Janeiro, Brazil) a review is done of the pertaining literature, and the contribution of the computed tomography for the diagnosis of this disease is emphasized. (Author) [pt

  6. Computed Tomography Study Of Complicated Bacterial Meningitis ...

    African Journals Online (AJOL)

    To monitor the structural intracranial complications of bacterial meningitis using computed tomography (CT) scan. Retrospective study of medical and radiological records of patients who underwent CT scan over a 4 year period. AUniversityTeachingHospital in a developing country. Thirty three patients with clinically and ...

  7. Computed tomography evaluation of petrous bone fractures ...

    African Journals Online (AJOL)

    Background: Petrous bone trauma is the sequel of blunt head injury and can have life threatening complications resulting in immediate mortality. Early detection and good knowledge of the Computed Tomography (CT) findings ensure prompt treatment of both fractures and complications. Objective: To document the ...

  8. Coordinate Metrology by Traceable Computed Tomography

    DEFF Research Database (Denmark)

    Müller, Pavel

    X-ray computed tomography (CT) is a measuring technique which has become an important technology in the production environment over the last years. Due to a number of advantages of CT compared to, e.g., coordinate measuring machines (CMMs), CT has been recently spread in the field of manufacturin...

  9. Neutron computed tomography of rat lungs.

    Science.gov (United States)

    Metzke, R W; Runck, H; Stahl, C A; Schillinger, B; Calzada, E; Mühlbauer, M; Schulz, M; Schneider, M; Priebe, H-J; Wall, W A; Guttmann, J

    2011-01-07

    Using conventional methods, three-dimensional imaging of the lung is challenging because of the low contrast between air and tissue and the large differences in dimensions between various pulmonary structures. The small distal airway structures and the high air-to-tissue ratio of lung tissue require an imaging technique which reliably discriminates between air and water. The objective of this study was to assess whether neutron computed tomography would satisfy such a requirement. This method utilizes the unique characteristic of neutrons of directly interacting with the atomic nucleus rather than being scattered by the atomic shell. Neutron computed tomography was tested in rats and allowed differentiation of larger lung structures (e.g., lobes) and distal airways. Airways could be identified reliably down to the sixth bronchial generation, in some cases even down to the tenth generation. The lung could be stabilized for sufficiently long exposure times to achieve an image resolution of 50-60 µm, which is the current physical resolution limit of the neutron computed tomography facility. Neutron computed tomography allowed excellent lung imaging without the need for additional tissue preparation or contrast media. The enhanced structural resolution obtained by applying this new research technique may improve understanding of lung physiology and respiratory therapy.

  10. Computed Tomography Analysis of NASA BSTRA Balls

    Energy Technology Data Exchange (ETDEWEB)

    Perry, R L; Schneberk, D J; Thompson, R R

    2004-10-12

    Fifteen 1.25 inch BSTRA balls were scanned with the high energy computed tomography system at LLNL. This system has a resolution limit of approximately 210 microns. A threshold of 238 microns (two voxels) was used, and no anomalies at or greater than this were observed.

  11. Computed tomography in severe protein energy malnutrition.

    OpenAIRE

    Househam, K C; de Villiers, J F

    1987-01-01

    Computed tomography of the brain was performed on eight children aged 1 to 4 years with severe protein energy malnutrition. Clinical features typical of kwashiorkor were present in all the children studied. Severe cerebral atrophy or brain shrinkage according to standard radiological criteria was present in every case. The findings of this study suggest considerable cerebral insult associated with severe protein energy malnutrition.

  12. Computed tomography of the iliopsoas muscle

    International Nuclear Information System (INIS)

    Nino-Murcia, M.; Wechsler, R.J.; Brennan, R.E.

    1983-01-01

    Computed tomography (CT) is an ideal method for the imaging of the psoas muscle. The authors present 13 cases of patients with psoas abnormalities diagnosed by CT. The CT features of the different pathologic entities and comparison of CT with other imaging modalities are discussed. (orig.)

  13. Diagnostic reference levels for paediatric computed tomography ...

    African Journals Online (AJOL)

    Objectives: To establish local diagnostic reference levels (LDRLs) for emergency paediatric head computed tomography (CT) scans performed at a South ... LDRL values were compared with several national DRLs from Europe and Australia. ... Standard age stratification for DRL and LDRL reporting is recommended.

  14. Computed tomography of tuberculous meningitis

    International Nuclear Information System (INIS)

    Sato, Noriko; Sato, Hiromi; Kawaguchi, Tetsuro; Fujita, Katsuzo; Tanaka, Makoto

    1982-01-01

    Recently, tuberculous meningitis has become rather rare except in areas where tuberculosis is still endemic. Six adolescents and young adults with tuberculous meningitis were evaluated by means of serial computerized tomography (CT), and the results were correlated with the findings of surgical specimens or autopsies. All cases showed meningeal irritation and fever at onset. CSF cultures revealed the presence of tuberculous bacilli. Four cases advanced rapidly to the clinical stage III and expired in a short period-between two weeks to one month from onset. On initial CT scanning, the disappearance of the basal cistern was a characteristic finding in all these cases. With the progression, an enhancement of the basal cistern on contrast injection, a localized hypodensity in adjacent parenchyma, and symmetrical ventricular dilatation appeared. Two autopsied cases showed tuberculous granulomas with purulent materials, thickened meninges, and caseous necrosis in the parenchyma around the basal cistern. The other two cases progressed rather slowly. CT findings at Stage II showed multiple enhanced spots in the basal subcortical area following contrast injection. Tuberculous granulomas were identified in these parts by means of explorative craniotomy. The authors point out the pathognomonic CT findings of tuberculous meningitis and emphasize the necessity of serial CT for the early detection and management of tuberculous meningitis. (author)

  15. Computed tomography of tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Noriko; Sato, Hiromi; Kawaguchi, Tetsuro; Fujita, Katsuzo; Tanaka, Makoto (Kobe Univ. (Japan). School of Medicine)

    1982-12-01

    Recently, tuberculous meningitis has become rather rare except in areas where tuberculosis is still endemic. Six adolescents and young adults with tuberculous meningitis were evaluated by means of serial computerized tomography (CT), and the results were correlated with the findings of surgical specimens or autopsies. All cases showed meningeal irritation and fever at onset. CSF cultures revealed the presence of tuberculous bacilli. Four cases advanced rapidly to the clinical stage III and expired in a short period-between two weeks to one month from onset. On initial CT scanning, the disappearance of the basal cistern was a characteristic finding in all these cases. With the progression, an enhancement of the basal cistern on contrast injection, a localized hypodensity in adjacent parenchyma, and symmetrical ventricular dilatation appeared. Two autopsied cases showed tuberculous granulomas with purulent materials, thickened meninges, and caseous necrosis in the parenchyma around the basal cistern. The other two cases progressed rather slowly. CT findings at Stage II showed multiple enhanced spots in the basal subcortical area following contrast injection. Tuberculous granulomas were identified in these parts by means of explorative craniotomy. The authors point out the pathognomonic CT findings of tuberculous meningitis and emphasize the necessity of serial CT for the early detection and management of tuberculous meningitis.

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed ...

  17. Misty mesentery: computed tomography findings

    International Nuclear Information System (INIS)

    Ahualli, Jorge; Mendez Uriburu, Luis; Ravera, Maria L.; Cikman, Pablo

    2008-01-01

    An alteration in the density of the mesenteric adipose tissue is often the principal clue of underlying mesenteric and bowel disease. The term 'Misty Mesentery' describes the computed tomographic appearance of mesenteric fat infiltrated by inflammatory cells, fluid (edema, lymph, and/or blood), tumor, and fibrosis. (author) [es

  18. Combined single-photon emission computed tomography / computed tomography: its use in bone pathology; La tomographie d'emission monophotonique couplee a la tomodensitometrie: applications en pathologie osseuse

    Energy Technology Data Exchange (ETDEWEB)

    Slosman, D.O. [Institut de Medecine Nucleaire, Clinique Generale-Beaulieu, Geneve (Switzerland); Martin, J.B. [Institut de Radiologie, Clinique Generale-Beaulieu, Geneve (Switzerland); Willi, J.P. [Hopitaux Univ. de Geneve, Service de Medecine Nucleaire, Geneve (Switzerland)

    2006-06-15

    The installation of CT in the gantry of a SPECT scanner has modified the Nuclear Medicine clinical setting. From the selective use of SPECT in cardiology, combined SPECT-CT represents a technological progress from which its future is related to the clinical application in general practice. In this review, we focused on skeleton investigation, because it represents not only the most frequent exam performed in private institute, but also because it is among the most widely studied. Well documented bone SPECT indications include: a) axial pain of unknown origin, b) additional investigation in the context of whole-body bone scintigraphy in oncology and c) osteo-articular specific functional investigation. Similarly to that of PET/CT, it is likely that SPECT/CT will grow in interest and clinical use. The association of metabolic/functional information to the structural information can be projected to SPECT/CT for which we can apply in clinical setting not only FDG but large varieties of radiopharmaceuticals available in general practice. Nevertheless, the limiting factor to this bright future could come from the nature of CT images produced (full scale contrast enhanced CT or a low mAs non-enhanced scan) as well as from the nature of collaborative design between radiology and nuclear medicine. An equilibrate cooperation will warrant the best profit to the patient. (author)

  19. Clinical utility of dental cone-beam computed tomography: current perspectives

    OpenAIRE

    Jaju, Prashant P; Jaju, Sushma P

    2014-01-01

    Prashant P Jaju,1 Sushma P Jaju21Oral Medicine and Radiology, 2Conservative Dentistry and Endodontics, Rishiraj College of Dental Sciences and Research Center, Bhopal, IndiaAbstract: Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology an...

  20. Thermoluminescent dosimetry in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lara C, A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Osorio V, M. [ISSSTE, Centro Medico Nacional 20 de Noviembre, Felix Cuevas 540, Col. del Valle, 03100 Ciudad de Mexico (Mexico); Hernandez O, O., E-mail: armando_lara_cam@yahoo.com.mx [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Ciudad de Mexico (Mexico)

    2016-10-15

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  1. Thermoluminescent dosimetry in computed tomography

    International Nuclear Information System (INIS)

    Lara C, A.; Rivera M, T.; Osorio V, M.; Hernandez O, O.

    2016-10-01

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  2. Microfocus computed tomography in medicine

    Science.gov (United States)

    Obodovskiy, A. V.

    2018-02-01

    Recent advances in the field of high-frequency power schemes for X-ray devices allow the creation of high-resolution instruments. At the department of electronic devices and Equipment of the St. Petersburg State Electrotechnical University, a model of a microfocus computer tomograph was developed. Used equipment allows to receive projection data with an increase up to 100 times. A distinctive feature of the device is the possibility of implementing various schemes for obtaining projection data.

  3. Cerebral candidiasis. Computed tomography appearance

    International Nuclear Information System (INIS)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-01-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  4. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  5. Orbital computed tomography: technical aspects

    International Nuclear Information System (INIS)

    Beck, T.J.; Rosenbaum, A.E.; Miller, N.R.

    1982-01-01

    Computed tomographic scanning has revolutionized the diagnosis and management of orbital disease. The best use of this methodology requires knowledge of the principles and appropriate attention to scanning protocols. Computed tomographic scanning of the orbit is a demanding technique requiring thin sections through planes precisely positioned from the topographical anatomy. Ideally, orbital CT should include both transverse axial and coronal sections: The pathological condition and its plane of growth will influence the selection of the optimal plane or section. Coronal sections may be obtained either directly or indirectly by computer reconstruction from contiguous transverse images. Sagittal or oblique sections or both also are useful and may be obtained directly or indirectly. Difficulty in patient positioning may preclude direct sagittal imaging, however. The use of intravenous contrast enhancement is not necessary as a routine technique unless a mass is identified or suspected. Where surgical resection or biopsy of a space-occupying lesion is contemplated, contrast enhancement can be valuable in assessing relative vascularity and aiding diagnostic specificity. It should be continually emphasized that CT is a powerful technology which, in orbital diagnosis, produces the highest yield when clinician and radiologist collaborate in the radiodiagnostic workup. The clinical information supplied by the referring ophthalmologist is used by the radiologist both in the selection of the appropriate techniques for investigation and in striving to achieve the most specific conclusion

  6. Proton computed tomography images with algebraic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzi, M. [Physics and Astronomy Department, University of Florence, Florence (Italy); Civinini, C.; Scaringella, M. [INFN - Florence Division, Florence (Italy); Bonanno, D. [INFN - Catania Division, Catania (Italy); Brianzi, M. [INFN - Florence Division, Florence (Italy); Carpinelli, M. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Cirrone, G.A.P.; Cuttone, G. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Presti, D. Lo [INFN - Catania Division, Catania (Italy); Physics and Astronomy Department, University of Catania, Catania (Italy); Maccioni, G. [INFN – Cagliari Division, Cagliari (Italy); Pallotta, S. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Randazzo, N. [INFN - Catania Division, Catania (Italy); Romano, F. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Sipala, V. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Talamonti, C. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Vanzi, E. [Fisica Sanitaria, Azienda Ospedaliero-Universitaria Senese, Siena (Italy)

    2017-02-11

    A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175 MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to ~1% and spatial resolutions <1 mm, achieved within processing times of ~15′ for a 512×512 pixels image prove that this technique will be beneficial if used instead of X-CT in hadron-therapy.

  7. Computed tomography for dimensional metrology

    DEFF Research Database (Denmark)

    Kruth, J.P.; Bartscher, M.; Carmignato, S.

    2011-01-01

    metrology, putting emphasis on issues as accuracy, traceability to the unit of length (the meter) and measurement uncertainty. It provides a state of the art (anno 2011) and application examples, showing the aptitude of CT metrology to: (i) check internal dimensions that cannot be measured using traditional...

  8. Dynamic X-ray computed tomography

    International Nuclear Information System (INIS)

    Grangeat, P.

    2003-01-01

    Paper Dynamic computed tomography (CT) imaging aims at reconstructing image sequences where the dynamic nature of the living human body is of primary interest. Main concerned applications are image-guided interventional procedures, functional studies and cardiac imaging. The introduction of ultra-fast rotating gantries along with multi-row detectors and in near future area detectors allows a huge progress toward the imaging of moving organs with low-contrast resolution. This paper gives an overview of the different concepts used in dynamic CT. A new reconstruction algorithm based on a voxel-specific dynamic evolution compensation is also presented. It provides four-dimensional image sequences with accurate spatio-temporal information, where each frame is reconstructed using a long-scan acquisition mode on several half-turns. In the same time, this technique permits to reduce the dose delivered per rotation while keeping the same signal to noise ratio for every frame using an adaptive motion-compensated temporal averaging. Results are illustrated on simulated data. (authors)

  9. Possibilities of computer tomography in multiple sclerosis

    International Nuclear Information System (INIS)

    Vymazal, J.; Bauer, J.

    1983-01-01

    Computer tomography was performed in 41 patients with multiple sclerosis, the average age of patients being 40.8 years. Native examinations were made of 17 patients, examinations with contrast medium of 19, both methods were used in the examination of 5 patients. In 26 patients, i.e. in almost two-thirds, cerebral atrophy was found, in 11 of a severe type. In 9 patients atrophy affected only the hemispheres, in 16 also the stem and cerebellum. The stem and cerebellum only were affected in 1 patient. Hypodense foci were found in 21 patients, i.e. more than half of those examined. In 9 there were multiple foci. In most of the 19 examined patients the hypodense changes were in the hemispheres and only in 2 in the cerebellum and brain stem. No hyperdense changes were detected. The value and possibilities are discussed of examinations by computer tomography multiple sclerosis. (author)

  10. Soil structure changes evaluated with computed tomography

    International Nuclear Information System (INIS)

    Pires, Luiz Fernando

    2010-01-01

    The objective of this work was to evaluate in millimetric scale changes in soil bulk density and porosity, using the gamma-ray computed tomography in soil samples with disturbed structure due to wetting and drying (W-D) cycles. Soil samples with 98.1 cm 3 were sieved using a 2 mm mesh and homogeneously packed in PVC cylinders. Soil samples were submitted to 1, 2, and 3 W-D cycles. Control samples were not submitted to W-D cycles. After repetitions of W-D cycles, soil sample porosity decreased and soil layers became denser. Computed tomography allowed a continuous analysis of soil bulk density and also soil porosity along millimetric (0.08 cm) layers, what cannot be provided by traditional methods used in soil physics. (author)

  11. Computed tomography of chest wall abscess

    International Nuclear Information System (INIS)

    Ikezoe, Junpei; Morimoto, Shizuo; Akira, Masanori

    1986-01-01

    Inflammatory lesions of the chest wall become less common because of the improvement of antibiotics and chemotherapeutic agents. Over a 5-year period, 7 patients with chest wall inflammatory diseases underwent chest computed tomography. These were 2 tuberculous pericostal abscesses, 2 empyema necessitatis, 1 spinal caries, and 2 bacterial chest wall abscesses (unknown organisms). Computed tomography (CT) helped in demonstrating the density, border, site, and extent of the lesions. CT images also demonstrated the accompaning abnormalities which included bone changes, pleural calcification, or old tuberculous changes of the lung. CT was very effective to demonstrate the communicating portions from the inside of the bony thorax to the outside of the bony thorax in 2 empyema necessitatis. (author)

  12. Computed Tomography Biomarkers of Vulnerable Coronary Plaques

    Directory of Open Access Journals (Sweden)

    Nyulas Tiberiu

    2016-12-01

    Full Text Available An unstable plaque has a high risk of thrombosis and at the same time for a fast progression of the stenosis degree. Also, “high-risk plaque” and “thrombosis-prone plaque” are used as synonym terms for characterization of a vulnerable plaque. The imaging biomarkers for vulnerable coronary plaques are considered to be spotty calcifications, active remodeling, low-density atheroma and the presence of a ring-like attenuation pattern, also known as the napkin-ring sign. Computed cardiac tomography can determine the plaque composition by assessing the plaque density, which is measured in Hounsfield units (HU. The aim of this manuscript was to provide an update about the most frequently used biomarkers of vulnerability in a vulnerable plaque with the help of computed cardiac tomography.

  13. Basic principle of cone beam computed tomography

    International Nuclear Information System (INIS)

    Choi, Yong Suk; Kim, Gyu Tae; Hwang, Eui Hwan

    2006-01-01

    The use of computed tomography for dental procedures has increased recently. Cone beam computed tomography(CBCT) systems have been designed for imaging hard tissues of the dentomaxillofacial region. CBCT is capable of providing high resolution in images of high diagnostic quality. This technology allows for 3-dimensional representation of the dentomaxillofacial skeleton with minimal distortion, but at lower equipment cost, simpler image acquisition and lower patient dose. Because this technology produces images with isotropic sub-millimeter spatial resolution, it is ideally suited for dedicated dentomaxillofacial imaging. In this paper, we provide a brief overview of cone beam scanning technology and compare it with the fan beam scanning used in conventional CT and the basic principles of currently available CBCT systems

  14. Dose in x-ray computed tomography

    Science.gov (United States)

    Kalender, Willi A.

    2014-02-01

    Radiation dose in x-ray computed tomography (CT) has become a topic of high interest due to the increasing numbers of CT examinations performed worldwide. This review aims to present an overview of current concepts for both scanner output metrics and for patient dosimetry and will comment on their strengths and weaknesses. Controversial issues such as the appropriateness of the CT dose index (CTDI) are discussed in detail. A review of approaches to patient dose assessment presently in practice, of the dose levels encountered and options for further dose optimization are also given and discussed. Patient dose assessment remains a topic for further improvement and for international consensus. All approaches presently in use are based on Monte Carlo (MC) simulations. Estimates for effective dose are established, but they are crude and not patient-specific; organ dose estimates are rarely available. Patient- and organ-specific dose estimates can be provided with adequate accuracy and independent of CTDI phantom measurements by fast MC simulations. Such information, in particular on 3D dose distributions, is important and helpful in optimization efforts. Dose optimization has been performed very successfully in recent years and even resulted in applications with effective dose values of below 1 mSv. In general, a trend towards lower dose values based on technical innovations has to be acknowledged. Effective dose values are down to clearly below 10 mSv on average, and there are a number of applications such as cardiac and pediatric CT which are performed routinely below 1 mSv on modern equipment.

  15. Patch-based models and algorithms for image processing: a review of the basic principles and methods, and their application in computed tomography.

    Science.gov (United States)

    Karimi, Davood; Ward, Rabab K

    2016-10-01

    Image models are central to all image processing tasks. The great advancements in digital image processing would not have been made possible without powerful models which, themselves, have evolved over time. In the past decade, "patch-based" models have emerged as one of the most effective models for natural images. Patch-based methods have outperformed other competing methods in many image processing tasks. These developments have come at a time when greater availability of powerful computational resources and growing concerns over the health risks of the ionizing radiation encourage research on image processing algorithms for computed tomography (CT). The goal of this paper is to explain the principles of patch-based methods and to review some of their recent applications in CT. We first review the central concepts in patch-based image processing and explain some of the state-of-the-art algorithms, with a focus on aspects that are more relevant to CT. Then, we review some of the recent application of patch-based methods in CT. Patch-based methods have already transformed the field of image processing, leading to state-of-the-art results in many applications. More recently, several studies have proposed patch-based algorithms for various image processing tasks in CT, from denoising and restoration to iterative reconstruction. Although these studies have reported good results, the true potential of patch-based methods for CT has not been yet appreciated. Patch-based methods can play a central role in image reconstruction and processing for CT. They have the potential to lead to substantial improvements in the current state of the art.

  16. Xenon as an adjunct in computed tomography

    International Nuclear Information System (INIS)

    Kendall, B.E.; Radue, E.W.; Zilkha, E.; Loh, L.

    1979-01-01

    Nonradioactive xenon was used for enhancement in computed tomography in a series of 18 patients requiring general anesthesia. The method and results are described. The properties of xenon are radically different from those of intravenous iodides, and the enhancement patterns demonstrate different aspects of both normal and abnormal tissues. In our limited experience, it has been of value in those isodense and low attenuation lesions that have not enhanced after intravenous Conray. (orig.) 891 MG/orig. 892 MB [de

  17. Computed tomography of the eye and orbit

    International Nuclear Information System (INIS)

    Hammerschlag, S.B.; Hesselink, J.R.; Weber, A.L.

    1982-01-01

    This book is the product of the evolution of computed tomography (CT) into subspecialization and the need for one source of information for the busy radiologist. The authors have succeeded in providing a readable overview of orbital CT as well as a reference book. The book is divided into seven major catagories of pathology (Neurofibromatosis, Primary Orbital Neoplasms, Secondary and Metastic Tumors of the Orbit, Vascular Disorders, Inflammatory Disease, Occular Lesions, and Trauma) after separate discussions of anatomy and technique

  18. Cranial computed tomography of the neurofibromatosis

    International Nuclear Information System (INIS)

    Fukuda, Teruo; Inoue, Yuichi; Shibakiri, Ippei

    1981-01-01

    The computed tomography (CT) was performed in 10 cases of neurofibromatosis. The CT scan showed the abnormal findings in 8 cases out of 10. Skull lesions were noted in 3 cases and intracranial tumors were found in 5 among which multiple neoplasms were seen in 3. Although reported cases were not large enough in number, the incidence and variety of the tumors were similar to others reported before CT era. (author)

  19. Computed tomography in gastrointestinal stromal tumors

    International Nuclear Information System (INIS)

    Ghanem, Nadir; Altehoefer, Carsten; Winterer, Jan; Schaefer, Oliver; Springer, Oliver; Kotter, Elmar; Langer, Mathias; Furtwaengler, Alex

    2003-01-01

    The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary (n=20) and (n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST ( 5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly

  20. Encapsulating peritonitis: computed tomography and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kadow, Juliana Santos; Fingerhut, Carla Jeronimo Peres; Fernandes, Vinicius de Barros; Coradazzi, Klaus Rizk Stuhr; Silva, Lucas Marciel Soares; Penachim, Thiago Jose, E-mail: vinicius.barros.fernandes@gmail.com [Pontificia Universidade Catolica de Campinas (PUC-Campinas), Campinas, SP (Brazil). Hospital e Maternidade Celso Pierro

    2014-07-15

    Sclerosing encapsulating peritonitis is a rare and frequently severe entity characterized by total or partial involvement of small bowel loops by a membrane of fibrous tissue. The disease presents with nonspecific clinical features of intestinal obstruction, requiring precise imaging diagnosis to guide the treatment. The present report emphasizes the importance of computed tomography in the diagnosis of this condition and its confirmation by surgical correlation. (author)

  1. Computed tomography of the calcaneus: normal anatomy

    International Nuclear Information System (INIS)

    Heger, L.; Wulff, K.

    1985-01-01

    The normal sectional anatomy of the calcaneus was studied as the background for interpretation of computed tomography (CT) of fractures. Multiplanar CT examination of the normal calcaneus was obtained, and sections were matched with a simplified anatomic model. Sectional anatomy in the four most important planes is described. This facilitates three-dimensional understanding of the calcaneus from sections and interpretation of CT sections obtained in any atypical plane

  2. Computed tomography in opportunistic lung infections

    International Nuclear Information System (INIS)

    Hartelius, H.

    1988-01-01

    Chest radiography in two teenage boys, one with Wiscott-Aldrich's syndrome and one with acute lymphatic leucemia in remission showed increased interstitial pattern. In both computed tomography (CT) of the lungs showed heavy interstitial pneumonia, rather different in appearance but in both cases equal to the CT findings in opportunistic lung infections known from immunoincompetent patients with for instance pneumocystis carinii and/or cytomegalo virus infections. In both patients the CT findings led to lung biopsy establishing the etiologic agent. (orig.)

  3. Physics and instrumentation of emission computed tomography

    International Nuclear Information System (INIS)

    Links, J.M.

    1986-01-01

    Transverse emission computed tomography can be divided into two distinct classes: single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT is usually accomplished with specially-adapted scintillation cameras, although dedicated SPECT scanners are available. The special SPECT cameras are standard cameras which are mounted on gantries that allow 360 degree rotation around the long axis of the head or body. The camera stops at a number of angles around the body (usually 64-128), acquiring a ''projection'' image at each stop. The data from these projections are used to reconstruct transverse images with a standard ''filtered back-projection'' algorithm, identical to that used in transmission CT. Because the scintillation camera acquires two-dimensional images, a simple 360 degree rotation around the patient results in the acquisition of data for a number of contiguous transverse slices. These slices, once reconstructed, can be ''stacked'' in computer memory, and orthogonal coronal and sagittal slices produced. Additionally, reorienting algorithms allow the generation of slices that are oblique to the long axis of the body

  4. Computer applications in clinical practice: An overview

    International Nuclear Information System (INIS)

    Levinson, D.

    1985-01-01

    This book reviews computer applications in clinical and nuclear medicine. Specifically discussed are: Diagnostic uses of computerized tomography; hyperthermia; research programs on x-radiation and medicine, and data acquisition systems of radiology

  5. Positron emission tomography/computed tomography imaging and rheumatoid arthritis.

    Science.gov (United States)

    Wang, Shi-Cun; Xie, Qiang; Lv, Wei-Fu

    2014-03-01

    Rheumatoid arthritis (RA) is a phenotypically heterogeneous, chronic, destructive inflammatory disease of the synovial joints. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the upgraded glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography/computed tomography with fluorine-18 fluorodeoxyglucose ((18) F-FDG PET/CT) is available to delineate inflammation with high sensitivity. Recently, several studies have indicated that FDG uptake in affected joints reflects the disease activity of RA. In addition, usage of FDG PET for the sensitive detection and monitoring of the response to treatment has been reported. Combined FDG PET/CT enables the detailed assessment of disease in large joints throughout the whole body. These unique capabilities of FDG PET/CT imaging are also able to detect RA-complicated diseases. Therefore, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  6. Therapy response evaluation with positron emission tomography-computed tomography.

    Science.gov (United States)

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice. Copyright © 2010. Published by Elsevier Inc.

  7. The role of computed tomography in modern paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Maudgil, D.D.; McHugh, K. E-mail: kmchugh@gosh.nhs.uk

    2002-08-01

    Computed tomography (CT) has developed a well-recognised role within paediatric uroradiology, especially in imaging of trauma, malignancy (in particular Wilms' tumour), atypical infection, and congenital urogenital abnormalities. CT can also be used for problem solving in nephrolithiasis and renal transplant assessment. These applications are illustrated and discussed, with an emphasis on particular information that can be gained from the CT study.

  8. Computed tomography angiography in the investigation of carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, A.J.P.; Mendelow, A.D.; Birchall, D

    2001-07-01

    The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. Goddard, A.J. P.et al. (2001)

  9. Computed tomography of common congenital lesions of the temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, H.Y. E-mail: drhyyuen@doctors.org.uk; Ahuja, A.T.; Wong, K.T.; Yue, V.; Hasselt, A.C. van

    2003-09-01

    This pictorial review describes the application of high-resolution computed tomography to the investigation and pre-operative work-up of the common lesions of congenital hearing loss, including congenital aural dysplasia, various congenital ossicular anomalies, inner ear dysmorphology, large vestibular aqueduct syndrome, and congenital absence of cochlear nerve and labyrinthitis ossificans from previous infection. The aim is to help radiologists to provide a more accurate diagnosis of underlying aetiology and assist in surgical planning.

  10. Use of Cone Beam Computed Tomography in Endodontics

    Science.gov (United States)

    Scarfe, William C.; Levin, Martin D.; Gane, David; Farman, Allan G.

    2009-01-01

    Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics. PMID:20379362

  11. Computed tomography to quantify tooth abrasion

    Science.gov (United States)

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  12. Fluorescence Computed Tomography with Polychromatic Source Data

    Science.gov (United States)

    Miqueles, Eduardo; De Pierro, Alvaro R.

    2013-02-01

    Fluorescence computed tomography is a synchrotron imaging technique aiming at reconstructing the fluorescence emission within a sample object. For a polychromatic source hitting the object, the amount of fluorescence detected is defined by a linear equation. For the monochromatic case, the operator is a Generalized Attenuated Radon Transform (GART). The main goal is to reconstruct the density function, given the sinogram data and the weight function. An eficient iterative algorithm for the inversion of the GART was presented recently by the authors. This inversion can only be performed if the weight function is previously known, which means that μ = μ(·, epsilon) and λ are also known. For monochromatic XFCT (acronym for x-rays fluorescence computed tomography), the determination of λ is a dificult task, and we have considered the approximation λ ≈ μ, which is valid for low energies ranging from 3Kev to 10Kev. So, for solving our problem, the first step is to find μ given the polychromatic sinogram. There are different approaches for this in the literature. Recently, an elegant and efficient method for solving this problem was introduced, using a fixed point algorithm. Opposite to this, where μ(·, epsilon) needs to be computed for all epsilon in E, we claim that the integral of μ(·, epsilon) for all epsilon has a physical meaning and provides a good aproximation for the solution. Also we present fast algorithm for computations.

  13. Concrescence: assessment of case by periapical radiography, cone beam computed tomography and micro-computed tomography.

    Science.gov (United States)

    Neves, Frederico Sampaio; Rovaris, Karla; Oliveira, Matheus Lima; Novaes, Pedro Duarte; de Freitas, Deborah Queiroz

    2014-04-01

    The aim of this article was to describe imaging aspects of concrescence analyzed by three imaging modalities. A second molar joined together with a third molar was imaged using digital periapical radiography, cone beam computed tomography (CBCT) and micro-computed tomography (Micro-CT). On periapical radiograph, the mesial root of the third molar is superimposed on the distal root of the second molar. On CBCT images, a large cementum union between bulbous roots was detected, confirming the diagnosis of concrescence. On micro-CT images, the cementum union appeared limited to the apical third of the roots. In conclusion, both computed tomography modalities allowed for the diagnosis of concrescence. However, only micro-CT provided the real extension of the cementum union.

  14. Mathematics in computed tomography and related techniques

    International Nuclear Information System (INIS)

    Sawicka, B.

    1992-01-01

    The mathematical basis of computed tomography (CT) was formulated in 1917 by Radon. His theorem states that the 2-D function f(x,y) can be determined at all points from a complete set of its line integrals. Modern methods of image reconstruction include three approaches: algebraic reconstruction techniques with simultaneous iterative reconstruction or simultaneous algebraic reconstruction; convolution back projection; and the Fourier transform method. There is no one best approach. Because the experimental data do not strictly satisfy theoretical models, a number of effects have to be taken into account; in particular, the problems of beam geometry, finite beam dimensions and distribution, beam scattering, and the radiation source spectrum. Tomography with truncated data is of interest, employing mathematical approximations to compensate for the unmeasured projection data. Mathematical techniques in image processing and data analysis are also extensively used. 13 refs

  15. A Simple Scatter Reduction Method in Cone-Beam Computed Tomography for Dental and Maxillofacial Applications Based on Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Chalinee Thanasupsombat

    2018-01-01

    Full Text Available The quality of images obtained from cone-beam computed tomography (CBCT is important in diagnosis and treatment planning for dental and maxillofacial applications. However, X-ray scattering inside a human head is one of the main factors that cause a drop in image quality, especially in the CBCT system with a wide-angle cone-beam X-ray source and a large area detector. In this study, the X-ray scattering distribution within a standard head phantom was estimated using the Monte Carlo method based on Geant4. Due to small variation of low-frequency scattering signals, the scattering signals from the head phantom can be represented as the simple predetermined scattering signals from a patient’s head and subtracted the projection data for scatter reduction. The results showed higher contrast and less cupping artifacts on the reconstructed images of the head phantom and real patients. Furthermore, the same simulated scattering signals can also be applied to process with higher-resolution projection data.

  16. Local tissue reaction after injection of contrast media on gastric wall of mouse: experimental study for application of contrast media to computed tomography lymphography.

    Science.gov (United States)

    Hwang, Sun-Hwi; Kim, Hyung-Ho; Park, Do Joong; Jee, Ye-Seob; Lee, Kyoung Ho; Kim, Young Hoon; Lee, Hye Seung; Lee, Hyuk-Joon; Yang, Han-Kwang

    2012-02-01

    Computed tomography (CT) lymphography is a simple technique of sentinel node navigation but tissue reaction after injection of contrast media has not been reported yet. NINETY MICE USED IN THIS STUDY WERE DIVIDED INTO THREE GROUPS: lipiodol, iopamidol, and normal saline. The test compounds were given by submucosal injection to the gastric wall of anesthetized mice. The specimens were subjected to histopathological examination. The mean grades of acute inflammatory response after iopamidol and lipiodol injection were significantly higher than control group. However, there was no significant difference between iopamidol and lipiodol injection. The mean grade of chronic inflammatory response and fibrosis showed no differences between groups. The presence or absence of fibrinoid necrosis and mesothelial hyperplasia showed no statistical differences at each time point between groups. The foam cell, which is similar to human signet ring cell carcinoma, were not identified in normal saline and iopamidol group, but were detected by postoperative day 7 in lipiodol group. We conclude that iopamidol and lipiodol when used as a contrast media of CT lymphography is an available material for preoperative sentinel node navigation surgery for gastric cancer with an acceptable incidence of pathological alterations in a mouse model. Our results are potentially useful to clinical (human) application.

  17. Positron Computed Tomography: Current State, Clinical Results and Future Trends

    Science.gov (United States)

    Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

    1980-09-01

    An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

  18. Positron computed tomography: current state, clinical results and future trends

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

    1980-01-01

    An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends

  19. RELIABILITY OF POSITRON EMISSION TOMOGRAPHY-COMPUTED TOMOGRAPHY IN EVALUATION OF TESTICULAR CARCINOMA PATIENTS.

    Science.gov (United States)

    Nikoletić, Katarina; Mihailović, Jasna; Matovina, Emil; Žeravica, Radmila; Srbovan, Dolores

    2015-01-01

    The study was aimed at assessing the reliability of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in evaluation of testicular carcinoma patients. The study sample consisted of 26 scans performed in 23 patients with testicular carcinoma. According to the pathohistological finding, 14 patients had seminomas, 7 had nonseminomas and 2 patients had a mixed histological type. In 17 patients, the initial treatment was orchiectomy+chemotherapy, 2 patients had orchiectomy+chemotherapy+retroperitoneal lymph node dissection, 3 patients had orchiectomy only and one patient was treated with chemotherapy only. Abnormal computed tomography was the main cause for the oncologist to refer the patient to positron emission tomography-computed tomography scan (in 19 scans), magnetic resonance imaging abnormalities in 1 scan, high level oftumor markers in 3 and 3 scans were perforned for follow-up. Positron emission tomography-computed tomography imaging results were compared with histological results, other imaging modalities or the clinical follow-up of the patients. Positron emission tomography-computed tomography scans were positive in 6 and negative in 20 patients. In two patients, positron emission tomography-computed tomography was false positive. There were 20 negative positron emission omography-computed tomography scans perforned in 18 patients, one patient was lost for data analysis. Clinically stable disease was confirmed in 18 follow-up scans performed in 16 patients. The values of sensitivty, specificity, accuracy, and positive- and negative predictive value were 60%, 95%, 75%, 88% and 90.5%, respectively. A hgh negative predictive value obtained in our study (90.5%) suggests that there is a small possibility for a patient to have future relapse after normal positron emission tomography-computed tomography study. However, since the sensitivity and positive predictive value of the study ire rather low, there are limitations of positive

  20. The use of computed tomography to assess asthma severity.

    Science.gov (United States)

    Mitsunobu, Fumihiro; Tanizaki, Yoshiro

    2005-02-01

    Chronic inflammation in asthma can also lead to airway remodeling, which contributes to airway narrowing. It may be possible to assess and quantify the extent of airway remodeling in vivo using computed tomography. This review examines recent developments in the evaluation of asthma severity using computed tomography, and the effect of treatment assessed by computed tomography. Asthma patients have thicker airways on computed tomography scans than do healthy control individuals, and the degree of thickening is related to the severity of disease, airflow obstruction, and airway reactivity. Recent studies have indicated that patients with severe asthma and irreversible airflow obstruction had longer disease duration, a greater inflammatory process and more airway abnormalities, assessed by high-resolution computed tomography, suggestive of airway remodeling. Other studies have shown that high-resolution computed tomography lung density correlates with airflow limitation and lung volume (but not with lung transfer factor), and also correlates with patient age and severity of asthma. More recently, two publications demonstrated the effect of treatment on airway wall thickness and lung density assessed by computed tomography in patients with asthma. High-resolution computed tomography is one of the most useful tools for imaging airways and parenchyma. Computed tomography scanning may be useful in determining which patients might benefit from more or less treatment. With additional advances in technology, it is likely that quantitative assessment by computed tomography will ultimately be a valuable tool for the study and treatment of chronic airway diseases.

  1. The value of positron emission tomography/computed tomography for evaluating metastatic disease in patients with pancreatic cancer.

    Science.gov (United States)

    Kim, Mi-Jin; Lee, Kwang Hyuck; Lee, Kyu Taek; Lee, Jong Kyun; Ku, Bon-Ho; Oh, Cho-Rong; Heo, Jin Seok; Choi, Seong-Ho; Choi, Dong Wook

    2012-08-01

    Routine application of positron emission tomography/computed tomography (PET/CT) for pancreatic cancer staging remains a controversial approach. The purpose of this study was to reassess the clinical impact of PET/CT for the detection of distant metastasis of pancreatic cancer. From January 2006 to June 2009, 125 patients with histologically proven pancreatic cancer that had undergone PET/CT at our hospital were retrospectively reviewed. To evaluate the clinical efficacy of PET/CT on the management plan, the post-PET/CT management plans were compared with the pre-PET/CT management plans. After the conventional staging workup, we determined that 76 patients (60.8%) had resectable lesions, whereas 48 patients had unresectable lesions. One patient underwent explorative laparotomy due to equivocal resectability. Positron emission tomography/computed tomography diagnosed distant metastasis in only 2 (2.6%) of the 76 patients with resectable lesions, and these patients did not undergo unnecessary surgical treatment. Complete resection was not performed in 8 of the 74 operative patients because they had distant metastasis detected during the operative procedure. Positron emission tomography/computed tomography diagnosed distant metastasis in 32 of the 44 patients with metastatic lesions that were histologically shown to have sensitivity of 72.7%. Positron emission tomography/computed tomography has a limited role in the evaluation of metastatic disease from pancreatic cancer.

  2. Unusual causes of obstructive jaundice. Computed tomography

    International Nuclear Information System (INIS)

    Rodriguez, E.; Pombo, F.; Cao, I.; Fernandez, R.; Riba da, M.

    1998-01-01

    The purpose of this study is to present selected computed tomography (CT) images showing unusual causes of obstructive jaundice. We reviewed retrospectively the Ct findings of obstructive jaundice in 227 patients. The most common causes of biliary obstruction were adenocarcinoma of the pancreatic head (n=77) and cholangiocarcinoma (n=65). In 13 cases (5.7%), the etiology of obstructive jaundice was unusual or exceptional: tuberculous adenitis (n=3), obstruction of afferent loop (n=2)signet ring cell adenocarcinoma (n=3); in duodenum, gallbladder and papilla of Water), Mirizzi syndrome (n=1), adenocarcinoma of the hepatic flexure (n=1), choledochal cyst (n=1) and pancreatic lymphoma (n=1). (Author) 13 refs

  3. Enlarged retrorectal space - indication for computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Krestin, G.P.; Steinbrich, W.; Beyer, D.

    1985-03-01

    The reasonable use of computed tomography in the diagnosis of an enlarged retrorectal space was analysed in 92 cases. CT is useful in differentiation of a pathologically enlarged retrorectal space without mucosal lesions of the rectum. It enables the separation between tumorous masses, proliferation of connective tissue (in retrorectal fibrosis or inflammatory disease) and pelvic lipomatosis. If simultaneous mucosal involvement in barium enema or rectoscopy - especially in rectal carcinoma or recurrent carcinoma of the rectum - is found, CT may show the perirectal extension of tumorous masses and thus help to clarify local operability.

  4. Contrast media on abdominal computed tomography

    International Nuclear Information System (INIS)

    Skalpe, I.O.; Oestensen, H.M.

    1984-01-01

    Abdominal computed tomography was performed in 55 patients before and after intravenous injection of 60 ml of a non-ionic (iohexol) or an ionic (metrizoate) contrast medium. The adverse effects were recorded and a series of measurements of attenuation values before and after the contrast medium injection was performed in the aorta and in hepatic and renal parenchyma. Only minor adverse effects were seen with both contrast media, but iohexol was clearly better tolerated than metrizoate. No difference in the enhancement properties was found between the two contrast media. (orig.)

  5. Multidetector Computed Tomography in Acute Joint Fractures

    International Nuclear Information System (INIS)

    Haapamaeki, V.V.; Kiuru, M.J.; Mustonen, A.O.; Koskinen, S.K.

    2005-01-01

    Conventional radiography plays an essential diagnostic role in the primary evaluation of acute joint trauma. In complex fractures, however, computed tomography (CT) is an imaging modality often used second to radiography. As a result of technical breakthroughs in the field, multidetector CT (MDCT) allows faster imaging and better temporal, spatial, and contrast resolution compared with conventional single-slice spiral CT. MDCT with multiplanar reformation is helpful in disclosing fracture patterns, particularly in complex joint fractures, where they reveal occult fractures and show the exact number of fracture components and their degree of displacement

  6. Sparse Image Reconstruction in Computed Tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...... and limitations of sparse reconstruction methods in CT, in particular in a quantitative sense. For example, relations between image properties such as contrast, structure and sparsity, tolerable noise levels, suficient sampling levels, the choice of sparse reconstruction formulation and the achievable image...

  7. Computed tomography features of small bowel volvulus

    International Nuclear Information System (INIS)

    Loh, Y.H.; Dunn, G.D.

    2000-01-01

    Small bowel volvulus is a cause of acute abdomen and commonly occurs in neonates and young infants. Although it is rare in adults in the Western world,' it is a relatively common surgical emergency in the Middle East, India and Central Africa. It is associated with a mortality rate of 10-67% and, hence, it is important to make an early diagnosis to expedite surgical intervention. Computed tomography has become an important imaging modality in diagnosis and a number of signs have been recognized in a handful of documented case reports. We describe a case of small bowel volvulus that illustrates these important CT signs. Copyright (1999) Blackwell Science Pty Ltd

  8. Computed tomography appearances of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    George, C. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)]. E-mail: cheriangeorge@hotmail.com; Al-Zwae, K. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Nair, S. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Cast, J.E.I. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)

    2007-08-15

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP.

  9. Computed tomography in neuronal ceroid lipofuscinosis

    International Nuclear Information System (INIS)

    Valavanis, A.; Schubiger, O.; Hayek, J.; Friede, R.L

    1981-01-01

    The computed tomography (CT) findings in a verified case of neutronal ceroid lipofuscinosis (NCL) are presented. CT revealed diffuse and severe cerebral atrophy, reflected by generalized subarachnoid space enlargement and symmetric ventricular dilatation. There was no evidence of abnormalities of the white matter. The CT features in our case of NCL correspond perfectly with the neuropathologic changes of the disease mentioned in the literature. Furthermore, CT is of considerable help in differentiating between those inherited metabolic brain diseases characterized primarily by white matter involvement and those presenting predominantly with changes of grey matter. (orig.) [de

  10. [Positron emission tomography/computed tomography for lung cancer staging].

    Science.gov (United States)

    Ladrón de Guevara H, David; Furnaro L, Francisca; Yévenes A, Sebastián; Clavero R, José Miguel; Lazo P, David; Rodríguez D, Patricio; Piottante B, Antonio; Pefaur D, Raúl; Pardo B, Claudio

    2015-01-01

    PET/CT (Positron Emission Tomography/Computed Tomography) is widely used in nodal and metastatic staging of lung cancer patients. To analyze PET/CT detection of metastatic disease in patients with lung cancer. We reviewed retrospectively F18Fluorodeoxyglucose PET/CT scans performed between December 2008 and December 2013. We selected 143 patients aged 30 to 92 years (63% males) with confirmed lung cancer referred for staging, with no previous treatment. We reviewed whole body PET/CT and brain magnetic resonance images. SUVmax (Standardized Uptake Value maximum) of primary pulmonary lesion, hilar/mediastinal nodes, and distant metastases were calculated. Histological types encountered were adenocarcinoma in 55%, squamous-cell in 15%, small-cell in 8%, large-cell in 6% and adeno-squamous in 2%. In 22 cases (15%) histology was not available. Nodal involvement was observed in 60% of patients (44% hilar and 48% mediastinal). Skip metastases (mediastinal involvement without hilum involvement) were encountered in 17% of cases, and were significantly more common among high uptake lung tumors (p < 0.01). Best SUVmax cut-off for node involvement was 4.4 for hilum and 4.0 for mediastinum (sensibility: 86.4%, specificity: 99.8%). Sixty six patients (46.2%) showed distant metastases on PET/CT. The most common metastases were osseous in 22%, adrenal in 16%, hepatic in14%, pulmonary in 14% and cerebral in 12%. PET/CT detected a second unexpected synchronic cancer in eight patients (6%). PET/CT is accurate for nodal staging using an uptake index as SUVmax. Distant metastases are common, especially in bone, adrenal glands and liver.

  11. Computed tomography with multidetectors in the diagnosis of coronary stenosis

    International Nuclear Information System (INIS)

    Lombo, Bernardo; Carvajal, Codos A; Tafur, Monica; Gomez, Rafael

    2007-01-01

    Coronary angiography that uses multislice spiral computed tomography is a noninvasive technique for the detection of coronary stenosis that has had significant improvements in recent years. The introduction of 16 and 64 row scanners, the development of synchronized scanning electrocardiogram and better reconstruction techniques permit higher spatial and temporal resolution that allows better identification of coronary plaques and significant obstructive coronary lesions. In the next years Multislice spiral computed tomography will continue maturing and it will become a useful non invasive diagnostic imaging tool for the diagnosis of coronary disease and will be integrated to the cardiologic management protocols. Our next review will be focused on the basic and technical aspects of the scanner, diagnostic performance and clinical applications of this new technology

  12. DIAGNOSTIC POSSIBILITIES OF 3D-COMPUTED TOMOGRAPHY WITH INTRALESIONAL APPLICATION OF CONTRAST MATERIAL IN A CASE OF VERY LARGE RADICULAR MAXILLARY CYST - A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Galina Gavazova

    2017-09-01

    Full Text Available Introduction: Diagnosis of odontogenic cysts despite their benign nature is a critical and challenging problem. Aim: The aim of this article is to demonstrate a different diagnostic approach in case of very large odontogenic cyst. Materials and Methods: This study was executed on one male patient aged of 38 using 3D computed tomography and contrast material inside the lesion. Differential diagnosis made by the residents was compared to the histopathological examination as the gold standard for identifying the nature of the cysts. Results: This diagnostic approach using 3D computed tomography combined with contrast material injected inside the lesion shows the real borders of the cyst of the maxilla and helps oral surgeon in planning the volume of the surgical intervention. Conclusion: Precise diagnose ensure the possibility of doing the optimal surgical intervention- a precondition for best wound healing.

  13. Computed tomography of human joints and radioactive waste drums

    International Nuclear Information System (INIS)

    Martz, Harry E.; Roberson, G. Patrick; Hollerbach, Karin; Logan, Clinton M.; Ashby, Elaine; Bernardi, Richard

    1999-01-01

    X- and gamma-ray imaging techniques in nondestructive evaluation (NDE) and assay (NDA) have seen increasing use in an array of industrial, environmental, military, and medical applications. Much of this growth in recent years is attributed to the rapid development of computed tomography (CT) and the use of NDE throughout the life-cycle of a product. Two diverse examples of CT are discussed, 1.) Our computational approach to normal joint kinematics and prosthetic joint analysis offers an opportunity to evaluate and improve prosthetic human joint replacements before they are manufactured or surgically implanted. Computed tomography data from scanned joints are segmented, resulting in the identification of bone and other tissues of interest, with emphasis on the articular surfaces. 2.) We are developing NDE and NDA techniques to analyze closed waste drums accurately and quantitatively. Active and passive computed tomography (A and PCT) is a comprehensive and accurate gamma-ray NDA method that can identify all detectable radioisotopes present in a container and measure their radioactivity

  14. Initial water quantification results using neutron computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.K. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States)], E-mail: axh174@psu.edu; Shi, L.; Brenizer, J.S.; Mench, M.M. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States)

    2009-06-21

    Neutron computed tomography is an important imaging tool in the field of non-destructive testing and in fundamental research for many engineering applications. Contrary to X-rays, neutrons can be attenuated by some light materials, such as hydrogen, but can penetrate many heavy materials. Thus, neutron computed tomography is useful in obtaining important three-dimensional information about a sample's interior structure and material properties that other traditional methods cannot provide. The neutron computed tomography system at Pennsylvania State University's Radiation Science and Engineering Center is being utilized to develop a water quantification technique for investigation of water distribution in fuel cells under normal conditions. A hollow aluminum cylinder test sample filled with a known volume of water was constructed for purposes of testing the quantification technique. Transmission images of the test sample at different angles were easily acquired through the synthesis of a dedicated image acquisition computer driving a rotary table controller and an in-house developed synchronization software package. After data acquisition, Octopus (version 8.2) and VGStudio Max (version 1.2) were used to perform cross-sectional and three-dimensional reconstructions of the sample, respectively. The initial reconstructions and water quantification results are presented.

  15. Computed tomography of human joints and radioactive waste drums

    Science.gov (United States)

    Martz, Harry E.; Roberson, G. Patrick; Hollerbach, Karin; Logan, Clinton M.; Ashby, Elaine; Bernardi, Richard

    1999-12-01

    X- and gamma-ray imaging techniques in nondestructive evaluation (NDE) and assay (NDA) have seen increasing use in an array of industrial, environmental, military, and medical applications. Much of this growth in recent years is attributed to the rapid development of computed tomography (CT) and the use of NDE throughout the life-cycle of a product. Two diverse examples of CT are discussed, 1.) Our computational approach to normal joint kinematics and prosthetic joint analysis offers an opportunity to evaluate and improve prosthetic human joint replacements before they are manufactured or surgically implanted. Computed tomography data from scanned joints are segmented, resulting in the identification of bone and other tissues of interest, with emphasis on the articular surfaces. 2.) We are developing NDE and NDA techniques to analyze closed waste drums accurately and quantitatively. Active and passive computed tomography (A&PCT) is a comprehensive and accurate gamma-ray NDA method that can identify all detectable radioisotopes present in a container and measure their radioactivity.

  16. Technical developments for computed tomography on the CENBG nanobeam line

    Energy Technology Data Exchange (ETDEWEB)

    Gordillo, N., E-mail: gordillo@cenbg.in2p3.fr [Universite Bordeaux 1, CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, CENBG, Chemin du Solarium, BP120, 33175 Gradignan (France); Habchi, C.; Daudin, L. [Universite Bordeaux 1, CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, CENBG, Chemin du Solarium, BP120, 33175 Gradignan (France); Sakellariou, A. [Research School of Physical Sciences and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Delalee, F.; Barberet, Ph.; Incerti, S.; Seznec, H.; Moretto, Ph. [Universite Bordeaux 1, CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, CENBG, Chemin du Solarium, BP120, 33175 Gradignan (France)

    2011-10-15

    The use of ion microbeams as probes for computed tomography has proven to be a powerful tool for the three-dimensional characterization of specimens a few tens of micrometers in size. Compared to other types of probes, the main advantage is that quantitative information about mass density and composition can be obtained directly, using specific reconstruction codes. At the Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG), this technique was initially developed for applications in cellular biology. However, the observation of the cell ultrastructure requires a sub-micron resolution. The construction of the nanobeam line at the Applications Interdisciplinaires des Faisceaux d'Ions en Region Aquitaine (AIFIRA) irradiation facility has opened new perspectives for such applications. The implementation of computed tomography on the nanobeam line of CENBG has required a careful design of the analysis chamber, especially microscopes for precise sample visualization, and detectors for scanning transmission ion microscopy (STIM) and for particle induced X-ray emission (PIXE). The sample can be precisely positioned in the three directions X, Y, Z and a stepper motor coupled to a goniometer ensures the rotational motion. First images of 3D tomography were obtained on a reference sample containing microspheres of certified diameter, showing the good stability of the beam and the sample stage, and the precision of the motion.

  17. Speeding up image reconstruction in computed tomography

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Computed tomography (CT) is a technique for imaging cross-sections of an object using X-ray measurements taken from different angles. In last decades a significant progress has happened there: today advanced algorithms allow fast image reconstruction and obtaining high-quality images even with missing or dirty data, modern detectors provide high resolution without increasing radiation dose, and high-performance multi-core computing devices are there to help us solving such tasks even faster. I will start with CT basics, then briefly present existing classes of reconstruction algorithms and their differences. After that I will proceed to employing distinctive architectural features of modern multi-core devices (CPUs and GPUs) and popular program interfaces (OpenMP, MPI, CUDA, OpenCL) for developing effective parallel realizations of image reconstruction algorithms. Decreasing full reconstruction time from long hours up to minutes or even seconds has a revolutionary impact in diagnostic medicine and industria...

  18. MO-AB-BRA-08: A Modular Multi-Source X-Ray Tube for Novel Computed Tomography Applications

    Energy Technology Data Exchange (ETDEWEB)

    Walker, B; Radtke, J; Chen, G; Mackie, T [University of Wisconsin Madison, Madison, WI (United States); Petry, G; Swader, R; Eliceiri, K [Morgridge Institute for Research, Madison, WI (United States)

    2016-06-15

    Purpose: To develop and build a practical implementation of an x-ray line source for the rapidly increasing number of multi-source imaging applications in CT. Methods: An innovative x-ray tube was designed using CST Particle Studio, ANSYS, and SolidWorks. A slowly varying magnetic field is synchronized with microsecond gating of multiple thermionic electron sources. Electrostatic simulations were run to optimize the geometry of the optics and prevent electrode arcing. Magnetostatic simulations were used for beam deflection studies and solenoid design. Particle beam trajectories were explored with an emphasis on focusing, acceleration, deflection, and space charge effects. Thermal constraints were analyzed for both transient and steady-state regimes. Electromagnetic simulations informed the design of a prototype unit under construction. Results: Particle tracking simulations for a benchtop system demonstrate that three 80 keV electron beams are able to be finely controlled and laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field in the hundreds of gauss. The beams are pulsed according to scanning sequences developed for implementation in a mock stationary CT scanner capable of a 30 ms temporal resolution. Beam spot diameters are approximately 1 mm for 30 mA beams and the stationary target stays well within thermal limits. The relevant hardware and control circuits were developed for incorporation into a physical prototype. Conclusion: A new multi-source x-ray tube was designed in a modular form factor to push the barriers of high-speed CT and spur growth in emerging imaging applications. This technology can be used as the basis for a stationary high-speed CT scanner, a system for generating a virtual fan-beam for dose reduction, or for reducing scatter radiation in cone-beam CT utilizing a tetrahedron beam CT geometry. A 2.4 kW benchtop system is currently being built to show proof of concept for the tube. Support

  19. Traumatic lung lesions: computed tomography findings

    International Nuclear Information System (INIS)

    Melo, Alessandro Severo Alves de; Moreira, Luiza Beatriz Melo; Marchiori, Edson

    2003-01-01

    Traumatic lesions of the lung are common findings in patients with thoracic trauma. These lesions are increasingly diagnosed using computed tomography, mostly due to the fast acquisition time helical techniques that allow evaluation of critically ill patients and an efficient therapeutic management. The authors studied 150 patients with thoracic trauma submitted to computed tomography that demonstrated lung contusions, atelectasis, lacerations and hematomas. Lung contusions were the most frequent lesions appearing as consolidation or ground-glass attenuation areas. Atelectasis, in subsegmentar and compressive patterns, were the second most common lesions observed. Lacerations appeared as consolidations with air or liquid level. Lung hematomas, characterized by round opacities, were the most rare lung lesions seen in only five cases. In this study, blunt thoracic trauma accounted for the majority of 120 cases whereas penetrating trauma occurred in 30 cases. The causes of blunt trauma in de crescent order of frequency were motor vehicle accidents, pedestrian hit by car, falls, motorcycle accidents and trashing. Penetrating traumas were caused by bullets or knives. (author)

  20. A review of X-ray computed axial tomography

    International Nuclear Information System (INIS)

    Schmidt, M.

    1989-01-01

    A review of Computed axial tomography (CAT) scanning literature outlining the theoretical and practical aspects of this technique with application in both medical diagnosis and industrial non-destructive inspection (NDI) is presented. Practical aspects of CAT scanning discussed include : radiation sources, currently available spatial and contrast resolution limits and the evolution of the computerized tomography (CT) system. It was found that monochromatic gamma rays are preferred to X-rays, especially for very high density materials, and that in medical CAT scanning, the special resolution is only, 0.5 mm while spatial resolutions of less than 50μm have been achieved in NDI. An increased number of scientific and industrial applications are anticipated (e.g. for studying sintering reactions), as the capital cost of CAT scanning decreased. 13 refs., 9 figs., 2 tabs

  1. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

    OpenAIRE

    Marli Batista Fernandes Vermelho; Ademir Silva Correia; Tânia Cibele de Almeida Michailowsky; Elizete Kazumi Kuniyoshi Suzart; Aline Santos Ibanês; Lanamar Aparecida Almeida; Zarifa Khoury; Mário Flores Barba

    2015-01-01

    Objective: To evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and Methods: Retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: Abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: Computed tomography has demonstrated to...

  2. A Clinical Evaluation Of Cone Beam Computed Tomography

    Science.gov (United States)

    2016-06-01

    reliability of multidetector computed tomography and cone beam computed tomography in the assessment of dental implant site dimensions. Dentomaxillofacial...A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY by Bryan James Behm, D.D.S. Lieutenant, Dental Corps United States Navy A thesis...submitted to the Faculty of the Endodontic Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health Sciences in

  3. Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

    Directory of Open Access Journals (Sweden)

    Vishruta A. Dumane

    2017-06-01

    Full Text Available Three dimensional planning for high-dose-rate (HDR brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS and the Groupe Européen de Curiethérapie – European Society for Radiotherapy and Oncology (GEC-ESTRO. In this document, we describe our experience with computed tomography (CT-based planning using the tandem/ring applicator. We discuss the influence of applicator geometry on doses to organs at risk (OARs, namely the bladder, rectum, and sigmoid. Through example cases with dose prescribed to point A, we demonstrate how adaptive planning can help achieve constraints to the OARs as per guidelines.

  4. Assesment of Acetabulum Fractures by Multidetector Computed Tomography

    International Nuclear Information System (INIS)

    Pinzon, Mariana; Pardo Patricia; Quintana, Jose

    2008-01-01

    Acetabular fractures were best classified by using multiplanar computed tomography, allowing the orthopedist a better surgical planning. This paper reviews different acetabulum fractures, traumatic mechanisms and classification.

  5. Computed tomography in the evaluation of diverticulitis

    International Nuclear Information System (INIS)

    Hulnick, D.H.; Megibow, A.J.; Balthazar, E.J.; Naidich, D.P.; Bosniak, M.A.

    1984-01-01

    Computed tomography (CT) was performed in 43 cases of colonic diverticulitis and compared with the contrast-enema examination (CE) in 37 patients. Findings on CT included inflammation of the pericolic fat in 98% of cases, diverticula in 84%, thickening of the colon wall in 70%, a pericolic abscess in 35%, peritonitis in 16%, a fistula in 14%, colon obstruction in 12%, and intramural sinus tracts in 9%. In addition to detecting ureteral and bladder involvement and distant abscess formation, CT was preferable for demonstrating the extent of pericolic inflammation, which was underestimated with CE in 41% of patients. Differential diagnosis of the CT findings is discussed. The authors indicate that CT should be the initial procedure in patients with suspected diverticulitis, particularly when CE is contraindicated

  6. Computed tomography findings in convergent strabismus fixus

    International Nuclear Information System (INIS)

    Ohta, Michitaka; Iwashige, Hiroyasu; Hayashi, Takao; Maruo, Toshio

    1995-01-01

    X-ray computed tomography (CT) of the eyeball and orbit revealed the cause of eye movement disorder in convergent strabismus fixus. The findings suggest that the disease can be diagnosed and treated at an early stage. Twelve cases of progressive esotropia with high myopia and 20 cases with normal visual acuity served as subjects in this study. The CT slice was parallel to the German horizontal plane, and the lens and medial and lateral rectus muscles were scanned. The average axial length of the affected eyes was significantly longer than in normal eyes. In progressive esotropia, the characteristic CT findings are an elongated eyeball, mechanical contact between the eyeball and lateral wall of the orbit, and a downward displacement of the lateral rectus muscle. Thus, it is reasonable to conclude that eye movement disorder in convergent strabismus fixus results from weakness of the lateral rectus muscle which has been displaced downward due to compression of the eyeball against the orbital wall. (author)

  7. Computed tomography of atresia auris congenita

    International Nuclear Information System (INIS)

    Kiuchi, Sousuke; Koide, Fujio

    1983-01-01

    Computed tomography was performed in 9 patients with atresia auris congenita. In this study, scans were done in axial or coronal projection with the CT/T body scanner. The external auditory canals were involved in varying degrees from mild narrowing to complete atresia. In partial atresia, CT scanning demonstrated the patency of the canal, and also showed the cardrum as a clearly defined soft tissue. Simulatenously, the associated middle ear anomalies were well demonstrated. One of the most common deformities of the ossicular chains was fusion of the malleus and incus. In some cases, these ossicles were dislocated, and occasionally were fixed to the atresia plate or attic wall. Other variations of the temporal bone could be assumed. We concluded that CT is the technique of choice to evaluate patients with atresia auris congenita. (author)

  8. Teleradiology for emergency cranial computed tomography

    International Nuclear Information System (INIS)

    Stranzinger, E.; Treumann, T.C.; Dreier, D.; Allgayer, B.

    2003-01-01

    Purpose: We report our experience with the teleradiologic service provided by a center hospital (CH) for emergency cranial computed tomography (CCT) in two regional hospitals (RH) during a 12-month period. The clinical and economic impact of teleradiology will be discussed as well as the acceptance by the clinicians of the regional hospitals. Material and Methods: In 2001, 213 CT-scans in 202 patients were performed and reported using teleradiology. Teleradiologic and final medical diagnosis were analysed by the medical reports. The transferral of the patients to a CH and their further treatment were checked. The referring physicians in the RH were questionnaired about the teleradiological support. Results: 18 (9%) patients had to be urgently transferred to a CH based on the CT findings in the teleradiological reports. 24 patients (11%) were transferred to a center hospital during further treatment. 80% of patients were treated in the RH. (orig.) [de

  9. Computer tomography of intracranial tumours and hematomas

    International Nuclear Information System (INIS)

    Tans, J.T.J.

    1978-01-01

    The value of computed tomography (CT) for the diagnosis of intracranial tumors and hematomas was investigated in a retrospective study comprising 220 patients. All C.T.scans are reviewed and described in detail. To assess the diagnostic accuracy, the original interpretation of the C.T.scans was compared with that of conventional neuroradiological and neurophysiological examinations. The aspect on C.T. of the various types of tumors and hematomas proved to vary widely and specific features were seldom seen. This holds particularly for the malignant tumors. Benign tumors such as meningeomas, adenomas and neurilemmomas showed a rather easily identifiable and almost identical picture of the C.T.scan, and diagnosis had to be based mainly on differences in localization. The hematomas, with the exception of the older intracerebral ones, showed the most characteristic C.T.abnormalities. (Auth.)

  10. Technological Evolution on Computed Tomography and Radioprotection

    International Nuclear Information System (INIS)

    Leite, Bruno Barros; Ribeiro, Nuno Carrilho

    2006-01-01

    Computed Tomography (CT) has been available since the 70s and has experienced a dramatic technical evolution. Multi-detector technology is our current standard, offering capabilities unthinkable only a decade ago. Yet, we must nor forget the ionizing nature of CT's scanning energy (X-rays). It represents the most important cause of medical-associated radiation exposure to the general public, with a trend to increase. It is compulsory to intervene with the objective of dose reduction, following ALARA policies. Currently there are some technical advances that allow dose reduction, without sacrificing diagnostic image capabilities. However, human intervention is also essential. We must keep investment on education so that CT exams are don when they are really useful in clinical decision. Alternative techniques should also be considered. Image quality must not be searched disregarding the biological effects of radiation. Generally, it is possible to obtain clinically acceptable images with lower dose protocols. (author)

  11. Quality assurance of computed tomography (CT) scanners

    International Nuclear Information System (INIS)

    Sankaran, A.; Sanu, K.K. . Email : a_sankaran@vsnl.com

    2004-01-01

    This article reviews the present status of research work and development of various test objects, phantoms and detector/instrumentation systems for quality assurance (QA) of computed tomography (CT) scanners, carried out in advanced countries, with emphasis on similar work done in this research centre. CT scanner is a complex equipment and routine quality control procedures are essential to the maintenance of image quality with optimum patient dose. Image quality can be ensured only through correlation between prospective monitoring of system components and tests of overall performance with standard phantoms. CT examinations contribute a large share to the population dose in advanced countries. The unique dosimetry problems in CT necessitate special techniques. This article describes a comprehensive kit developed indigenously for the following QA and type approval tests as well as for research studies on image quality/dosimetry on CT scanners

  12. Mouse brain imaging using photoacoustic computed tomography

    Science.gov (United States)

    Lou, Yang; Xia, Jun; Wang, Lihong V.

    2014-03-01

    Photoacoustic computed tomography (PACT) provides structural and functional information when used in small animal brain imaging. Acoustic distortion caused by bone structures largely limits the deep brain image quality. In our work, we present ex vivo PACT images of freshly excised mouse brain, intending that can serve as a gold standard for future PACT in vivo studies on small animal brain imaging. Our results show that structures such as the striatum, hippocampus, ventricles, and cerebellum can be clearly di erentiated. An artery feature called the Circle of Willis, located at the bottom of the brain, can also be seen. These results indicate that if acoustic distortion can be accurately accounted for, PACT should be able to image the entire mouse brain with rich structural information.

  13. Data processing device for computed tomography system

    International Nuclear Information System (INIS)

    Nakayama, N.; Ito, Y.; Iwata, K.; Nishihara, E.; Shibayama, S.

    1984-01-01

    A data processing device applied to a computed tomography system which examines a living body utilizing radiation of X-rays is disclosed. The X-rays which have penetrated the living body are converted into electric signals in a detecting section. The electric signals are acquired and converted from an analog form into a digital form in a data acquisition section, and then supplied to a matrix data-generating section included in the data processing device. By this matrix data-generating section are generated matrix data which correspond to a plurality of projection data. These matrix data are supplied to a partial sum-producing section. The partial sums respectively corresponding to groups of the matrix data are calculated in this partial sum-producing section and then supplied to an accumulation section. In this accumulation section, the final value corresponding to the total sum of the matrix data is calculated, whereby the calculation for image reconstruction is performed

  14. Analysis of airways in computed tomography

    DEFF Research Database (Denmark)

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...... have become the standard with which to assess emphysema extent but airway abnormalities have so far been more challenging to quantify. Automated methods for analysis are indispensable as the visible airway tree in a CT scan can include several hundreds of individual branches. However, automation...... the Danish Lung Cancer Screening Trial. This includes methods for extracting airway surfaces from the images and ways of achieving comparable measurements in airway branches through matching and anatomical labelling. The methods were used to study effects of differences in inspiration level at the time...

  15. Quality assessment of clinical computed tomography

    Science.gov (United States)

    Berndt, Dorothea; Luckow, Marlen; Lambrecht, J. Thomas; Beckmann, Felix; Müller, Bert

    2008-08-01

    Three-dimensional images are vital for the diagnosis in dentistry and cranio-maxillofacial surgery. Artifacts caused by highly absorbing components such as metallic implants, however, limit the value of the tomograms. The dominant artifacts observed are blowout and streaks. Investigating the artifacts generated by metallic implants in a pig jaw, the data acquisition for the patients in dentistry should be optimized in a quantitative manner. A freshly explanted pig jaw including related soft-tissues served as a model system. Images were recorded varying the accelerating voltage and the beam current. The comparison with multi-slice and micro computed tomography (CT) helps to validate the approach with the dental CT system (3D-Accuitomo, Morita, Japan). The data are rigidly registered to comparatively quantify their quality. The micro CT data provide a reasonable standard for quantitative data assessment of clinical CT.

  16. Advanced proton imaging in computed tomography

    CERN Document Server

    Mattiazzo, S; Giubilato, P; Pantano, D; Pozzobon, N; Snoeys, W; Wyss, J

    2015-01-01

    In recent years the use of hadrons for cancer radiation treatment has grown in importance, and many facilities are currently operational or under construction worldwide. To fully exploit the therapeutic advantages offered by hadron therapy, precise body imaging for accurate beam delivery is decisive. Proton computed tomography (pCT) scanners, currently in their R&D phase, provide the ultimate 3D imaging for hadrons treatment guidance. A key component of a pCT scanner is the detector used to track the protons, which has great impact on the scanner performances and ultimately limits its maximum speed. In this article, a novel proton-tracking detector was presented that would have higher scanning speed, better spatial resolution and lower material budget with respect to present state-of-the-art detectors, leading to enhanced performances. This advancement in performances is achieved by employing the very latest development in monolithic active pixel detectors (to build high granularity, low material budget, ...

  17. Analysis of mesenteric thickening on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hideyuki; Sekiya, Tohru; Miyakawa, Kunihisa; Ozaki, Masatoki; Katsuyama, Naofumi; Nakano, Masao (University of the Ryukyu, Okinawa (Japan). School of Medicine)

    1990-12-01

    Computed tomography (CT) provides noninvasive information in the evaluation of abnormalities of the gastrointestinal tract by direct imaging of the bowel wall and adjacent mesentery. Several prior studies have discussed the variable CT appearances of mesenteric abnormalities, such as lymphoma, metastasis, inflammatory disease and edema. Although mesenteric thickening was mentioned in these studies, no study has provided a detailed analysis of the CT appearance of the thickened mesentery. Two characteristic types of mesenteric thickening were identified in 47 patients. Type I is 'intramesenteric thickening', which was noted in 25 patients with vascular obstruction, inflammatory disease and edema. Type II is 'mesenteric surface thickening', which was noted in 22 patients with peritonitis carcinomatosa, peritoneal mesothelioma, tuberculous peritonitis and pseudomyxoma peritoneai. An understanding of these two types of mesenteric diseases is important in the identification of mesenteric pathology. (author).

  18. Analysis of mesenteric thickening on computed tomography

    International Nuclear Information System (INIS)

    Takano, Hideyuki; Sekiya, Tohru; Miyakawa, Kunihisa; Ozaki, Masatoki; Katsuyama, Naofumi; Nakano, Masao

    1990-01-01

    Computed tomography (CT) provides noninvasive information in the evaluation of abnormalities of the gastrointestinal tract by direct imaging of the bowel wall and adjacent mesentery. Several prior studies have discussed the variable CT appearances of mesenteric abnormalities, such as lymphoma, metastasis, inflammatory disease and edema. Although mesenteric thickening was mentioned in these studies, no study has provided a detailed analysis of the CT appearance of the thickened mesentery. Two characteristic types of mesenteric thickening were identified in 47 patients. Type I is 'intramesenteric thickening', which was noted in 25 patients with vascular obstruction, inflammatory disease and edema. Type II is 'mesenteric surface thickening', which was noted in 22 patients with peritonitis carcinomatosa, peritoneal mesothelioma, tuberculous peritonitis and pseudomyxoma peritoneai. An understanding of these two types of mesenteric diseases is important in the identification of mesenteric pathology. (author)

  19. A computed tomography study of Alzheimer's disease

    International Nuclear Information System (INIS)

    Arai, H.; Kobayashi, K.; Juntendo Univ. School of Medicine, Tokyo; Ikeda, Y.; Nagao, Y.; Ogihara, R.; Kosaka, K.; Psychiatric Research Inst. of Tokyo

    1983-01-01

    Computed tomography (CT) was used to study cerebral atrophy in 18 patients with clinically diagnosed Alzheimer's disease of presenile type and in 14 healthy age-matched subjects as controls. Using the computerized planimetric method, Subarachnoid Space Volume Index and Ventricle Volume Index were calculated as the measure of cortical atrophy and ventricular dilatation respectively. From the results the following conclusions were drawn: 1. The cerebral atrophy in Alzheimer patients could be attributable to the disease processes rather than to physiological aging of the brain. 2. The degree of atrophy increases in parallel with the progress of the clinical stage, and the cortical atrophy is already apparent at an early stage, whereas the ventricular dilatation becomes pronounced at later stages. 3. CT could be one of the most useful clinical tests available for the diagnosis of Alzheimer's disease. (orig.) [de

  20. Computed tomography findings of malignant pleural mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Shiota, Yutaro; Sato, Toshio; Yamaguchi, Kazuo; Ono, Tetsuya; Kaji, Masaro; Niiya, Harutaka (Kure Kyosai Hospital, Hiroshima (Japan))

    1994-04-01

    Computed tomography (CT) findings were assessed in 7 patients with malignant mesothelioma. CT findings were also reviewed in 9 patients with lung cancer and pleuritis carcinomatosa and in 11 patients with tuberculous pleuritis. Five patients with malignant mesothelioma underwent CT scans twice, on admission and from 1 to 7 months after admission. Tuberculous pleuritis could be distinguished from pleuritis carcinomatosa and malignant mesothelioma by the presence or absence of pleural nodularity and chest wall invasion. Although it was difficult to identify specific CT features clearly distinguishing malignant mesothelioma from pleuritis carcinomatosa, characteristic findings of malignant mesothelioma appeared to include the rapid development and progression of pleural rind and a tendency to spread directly into the chest wall. We divided the pleural into the four regions; upper anterior, upper posterior, lower anterior and lower posterior regions. Pleural changes were more frequently seen in the lower pleural regions than in the upper pleural regions in malignant mesothelioma. (author).

  1. Computed tomography findings of malignant pleural mesothelioma

    International Nuclear Information System (INIS)

    Shiota, Yutaro; Sato, Toshio; Yamaguchi, Kazuo; Ono, Tetsuya; Kaji, Masaro; Niiya, Harutaka

    1994-01-01

    Computed tomography (CT) findings were assessed in 7 patients with malignant mesothelioma. CT findings were also reviewed in 9 patients with lung cancer and pleuritis carcinomatosa and in 11 patients with tuberculous pleuritis. Five patients with malignant mesothelioma underwent CT scans twice, on admission and from 1 to 7 months after admission. Tuberculous pleuritis could be distinguished from pleuritis carcinomatosa and malignant mesothelioma by the presence or absence of pleural nodularity and chest wall invasion. Although it was difficult to identify specific CT features clearly distinguishing malignant mesothelioma from pleuritis carcinomatosa, characteristic findings of malignant mesothelioma appeared to include the rapid development and progression of pleural rind and a tendency to spread directly into the chest wall. We divided the pleural into the four regions; upper anterior, upper posterior, lower anterior and lower posterior regions. Pleural changes were more frequently seen in the lower pleural regions than in the upper pleural regions in malignant mesothelioma. (author)

  2. Computed Tomography findings in Fournier's gangrene

    International Nuclear Information System (INIS)

    Isusi, M.; Campo, M.; Oleaga, L.; Grande, J.; Grande, D.

    2000-01-01

    To assess the utility of computed tomography (CT) as an imaging technique in the diagnosis and determination of the extension of Fournier's gangrene (FG). We report the cases of six patients who had been clinically diagnosed as having FG, CT, enhanced by oral and intravenous contrast media, was performed in all the patients. All six patients presented soft tissue masses and gas in the scrotal region, which were also detected in the perineal region in five. In two patients, the gas extended toward anterior abdominal wall and in one of them, it also observed in anterior and posterior para renal space. The major predisposing factors were diabetes and alcoholism and the most common triggering factor was urologic disease. CT confirms the existence of FG and aids in assessing its extension and, in some cases, in identifying the underlying cause. (Author) 15 refs

  3. Assessment of the impact of application of singlephoton emission computed tomography and SPECT-CT on lesion categorisation in bone scintigraphy

    Directory of Open Access Journals (Sweden)

    Garba H. Yunusa

    2016-06-01

    Full Text Available Objectives: To assess initial experience with the use of a new single-photon emission computed tomography-computed tomography (SPECT-CT in the evaluation of lesions. Methods: The folder number, radiopharmaceutical used and type of scan of patients examined with a new Siemens T6 SPECT-CT between 02 April 2016 and 31 December 2013 were retrieved. The number of 99mTc-MDP bone scans was sufficient for a detailed analysis. The scans were re-processed and reported by the observer before he was given any clinical information. Whole body planar, whole body planar plus SPECT and whole body planar plus SPECT-CT images were assessed successively in three separate sessions at least 2 weeks apart. At each session, the certainties of detection, localisation and categorisation of each lesion were recorded. Results: A total of 539 lesions were seen on the whole body, SPECT and computed tomography (CT images in 133 patients. The whole body images showed no lesions in 3 patients and 378 lesions in 130 patients. SPECT detected 122 additional lesions in 79 patients. Thirty-nine (12.2% lesions were seen only on CT in 32 (24.1% patients. For the 261 lesions seen on the planar images in the SPECT field of view, lesion detection was definite in 233 (89.3%, localisation definite in 151 (57.9% and categorisation definite in 123 (47.1% lesions. On the SPECT, definite lesion detection, localisation and categorisation were recorded, respectively, for 259 (99.2%, 228 (87.4% and 176 (67.4% of the 261 lesions. Lesion detection, localisation and categorisation certainties were definite for 100%, 99.1% and 94.7% of the SPECT-CT lesions, respectively. Conclusion: SPECT markedly improves lesion detection and localisation, and CT enhances lesion categorisation.

  4. Evaluation of one year brain Computed Tomography scans at the ...

    African Journals Online (AJOL)

    Background: Advancement in technology has contributed immensely to medical practice. Computed tomography (CT), a yield of advanced technology has revolutionized the practice of neuroscience. Aim: To evaluate the first one year of brain computed tomography scan in the permanent site of University of Port Harcourt ...

  5. Diagnosis of lumbar disc hernia with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizumi, Atsuro; Ohira, Nobuhiro; Ojima, Tadashi; Oshida, Midori; Horaguchi, Mitsuru (Tohoku Rosai Hospital, Sendai (Japan))

    1982-07-01

    Results of computed tomography performed on patients with clinically diagnosed hernia were compared with those of myelography and operative findings. This comparative study suggested that computed tomography is quite different from other methods and very useful in diagnosis of hernia. Some cases of hernia were shown, and the characteristics of CT were reviewed.

  6. Diagnosis of lumbar disc hernia with computed tomography

    International Nuclear Information System (INIS)

    Yoshizumi, Atsuro; Ohira, Nobuhiro; Ojima, Tadashi; Oshida, Midori; Horaguchi, Mitsuru

    1982-01-01

    Results of computed tomography performed on patients with clinically diagnosed hernia were compared with those of myelography and operative findings. This comparative study suggested that computed tomography is quite different from other methods and very useful in diagnosis of hernia. Some cases of hernia were shown, and the characteristics of CT were reviewed. (Ueda, J.)

  7. Cone beam computed tomography in Endodontics - a review

    NARCIS (Netherlands)

    Patel, S.; Durack, C.; Abella, F.; Shemesh, H.; Roig, M.; Lemberg, K.

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on

  8. Computer algebra applications

    International Nuclear Information System (INIS)

    Calmet, J.

    1982-01-01

    A survey of applications based either on fundamental algorithms in computer algebra or on the use of a computer algebra system is presented. Recent work in biology, chemistry, physics, mathematics and computer science is discussed. In particular, applications in high energy physics (quantum electrodynamics), celestial mechanics and general relativity are reviewed. (Auth.)

  9. The use of contrast media in computer tomography

    International Nuclear Information System (INIS)

    Galanski, M.; Cramer, B.M.; Drewes, G.

    1980-01-01

    There are a variety of applications for contrast media in CT. They can be used for better anatomic demonstration or for showing pathological processes. Nearly all available contrast media may be found useful. Intravenously injected renographic contrast media are most commonly employed. In addition to their inherent contrast, specific pharmaco-kinetic changes may be of diagnostic value. This adds some knowledge of function to the purely morphological information obtained by computer tomography. For this purpose, contrast has to be injected rapidly and a fast scanner must be used (so-called angio-CT). (orig.) [de

  10. Micro Computer Tomography for medical device and pharmaceutical packaging analysis.

    Science.gov (United States)

    Hindelang, Florine; Zurbach, Raphael; Roggo, Yves

    2015-04-10

    Biomedical device and medicine product manufacturing are long processes facing global competition. As technology evolves with time, the level of quality, safety and reliability increases simultaneously. Micro Computer Tomography (Micro CT) is a tool allowing a deep investigation of products: it can contribute to quality improvement. This article presents the numerous applications of Micro CT for medical device and pharmaceutical packaging analysis. The samples investigated confirmed CT suitability for verification of integrity, measurements and defect detections in a non-destructive manner. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Patient Dose From Megavoltage Computed Tomography Imaging

    International Nuclear Information System (INIS)

    Shah, Amish P.; Langen, Katja M.; Ruchala, Kenneth J.; Cox, Andrea; Kupelian, Patrick A.; Meeks, Sanford L.

    2008-01-01

    Purpose: Megavoltage computed tomography (MVCT) can be used daily for imaging with a helical tomotherapy unit for patient alignment before treatment delivery. The purpose of this investigation was to show that the MVCT dose can be computed in phantoms, and further, that the dose can be reported for actual patients from MVCT on a helical tomotherapy unit. Methods and Materials: An MVCT beam model was commissioned and verified through a series of absorbed dose measurements in phantoms. This model was then used to retrospectively calculate the imaging doses to the patients. The MVCT dose was computed for five clinical cases: prostate, breast, head/neck, lung, and craniospinal axis. Results: Validation measurements in phantoms verified that the computed dose can be reported to within 5% of the measured dose delivered at the helical tomotherapy unit. The imaging dose scaled inversely with changes to the CT pitch. Relative to a normal pitch of 2.0, the organ dose can be scaled by 0.67 and 2.0 for scans done with a pitch of 3.0 and 1.0, respectively. Typical doses were in the range of 1.0-2.0 cGy, if imaged with a normal pitch. The maximal organ dose calculated was 3.6 cGy in the neck region of the craniospinal patient, if imaged with a pitch of 1.0. Conclusion: Calculation of the MVCT dose has shown that the typical imaging dose is approximately 1.5 cGy per image. The uniform MVCT dose delivered using helical tomotherapy is greatest when the anatomic thickness is the smallest and the pitch is set to the lowest value

  12. Terahertz Computed Tomography of NASA Thermal Protection System Materials

    Science.gov (United States)

    Roth, D. J.; Reyes-Rodriguez, S.; Zimdars, D. A.; Rauser, R. W.; Ussery, W. W.

    2011-01-01

    A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

  13. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science...

  14. Applicability of a geometrical model coupled to computed tomography to characterize the transport properties of porous materials: comparison with through diffusion experiments

    International Nuclear Information System (INIS)

    Chagneau, Aurelie; Claret, Francis; Made, Benoit; Tuckermann, Juergen; Enzmann, Frieder; Schaefer, Thorsten

    2012-01-01

    Document available in extended abstract form only. The main objective of the present study is to characterize the evolution of diffusion properties of porous materials as influenced by porosity changes. When under geochemical perturbation, the rocks porosity evolves with dissolution/precipitation processes. The impact of changes in porosity on the diffusion phenomena are implemented in most geochemical models using Archie's law: D e /D 0 = ε m where D e and D 0 are the effective diffusivity and the diffusivity of the element in water in m 2 s -1 , respectively, e is the overall porosity and m is the cementation factor. The factor m is a function of pores geometry and compaction. Depending on the rock considered, its value ranges from 1 to 3. Moreover, as the porosity decreases the connectivity of pores changes. At low overall porosity, the effective porosity is the determining parameter affecting effective diffusivity. Therefore, the Archie's law needs to be modified to accurately predict geochemical migration of pollutants such as radio-elements in a dynamic system. Our experimental approach is divided in two complementary parts: (i) diffusion experiments conducted in hot-laboratory using radiotracers and (ii) time-dependant monitoring of porosity evolution in three dimensions using computed tomography (CT). For the two approaches, simplified systems are used to define the co-evolution of porosity and diffusivity using a minimum number of parameters, in order to optimize the understanding of the basics and determining processes. For this purpose, three materials are used in diffusion columns: (i) rods of porous ceramic, (ii) artificial silica beads of different particle sizes (SiLi R ) and (iii) purified sea sand (Merck R ). The precipitation of simple salts, celestite (SrSO 4 ) and strontianite (SrCO 3 ), is forced in the porous material once placed in diffusion columns. Celestite and strontianite were chosen for their fast precipitation kinetics, and because

  15. Emission computer tomography of the left ventricle

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, W.; Felix, R.; Calder, D.; Golde, G.; Botsch, H.

    1983-10-01

    Tomographic studies and time-dependent tomograms on phantoms and patients were carried out using a 7-pinhole collimator in order to study the clinical value of ECG-triggered tomographic radionuclid ventriculography. A suitable computer programme has been developed. The results have shown that it is possible to evaluate local contraction abnormalities by this method. Using a left oblique position of the collimator (LAO (45/sup 0/) - cranial (15/sup 0/)), emission computer tomography is aligned with the longitudinal axis for the heart. In this way, a single projection is sufficient to show the montility of the anterior and posterior walls and of the septum. Hypokinesis, akinesis or dyskinesis can be recognised visually. The localisation and extent of the defect can be determined through the 7-pinhole collimator. Reconstructed images of the triggered radionuclide scintigrams show excellent marginal definition. In the RAO projection the left ventricle can be seen without superimposition and images obtained which equal those of a first-pass technique.

  16. Application of Dual-Source-Computed Tomography in Pediatric Cardiology in Children Within the First Year of Life.

    Science.gov (United States)

    Hausmann, P; Stenger, A; Dittrich, S; Cesnjevar, R; Rüffer, A; Hammon, M; Uder, M; Rompel, O; Glöckler, M

    2016-02-01

    To assess fields of application and value of dual source computed tomography (DSCT) for diagnostics and therapy in patients with congenital heart disease during their first year of life. Evaluation of image quality, surgical use and radiation exposure of 2nd and 3 rd generation DSCT. DSCT was applied in 118 cases between January 2012 and October 2014 for diagnostics of congenital heart defects. 2nd generation was used in 91 cases until April 2014 and 3 rd generation in 27 cases during the period thereafter. 3 D reconstructions of the image data were created for clinical diagnostics and planning of interventions. Image quality was assessed using a 4-point-scale. The visibility of the mammary arteries was analyzed, and signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. The usefulness of 3D-reconstructions for surgical planning was rated using a 5-point-scale. Radiation exposure and contrast dye consumption were determined. All cases were analyzed retrospectively. DSCT was successfully used in 118 cases. All image data obtained were interpretable. More than 60 percent of cases did not show any artifacts. The mammary arteries were visible down to the diaphragmatic arch in more than 80 percent of cases. Diagnostic value and surgical benefit were evaluated as "useful" or as "essential" in all cases. Median radiation dose was 0.4 mSv and 0.27 mSv for the 2nd and 3 rd generation DSCT, respectively. Consumption of contrast dye was 2 ml/kg in all cases. DSCT is a modern and extremely helpful technique for diagnostics and planning of interventions in patients with complex congenital heart defects. Extracardiac vascular structures in particular can be depicted three-dimensionally at high resolution. The use of iterative reconstruction with 3 rd generation DSCT yielded image quality similar to that of 2nd generation DSCT at considerably reduced radiation exposure level compared to 2nd generation DSCT. 3 rd generation DSCT is a low

  17. Giant hepatic cavernous hemangioma. Findings on computed helical tomography

    International Nuclear Information System (INIS)

    Castrillon, German A; Montoya, Maria del Pilar; Soto, Jorge A

    2010-01-01

    Objective: To describe computed helical tomography characteristics of the giant hepatic cavernous hemangioma. Method: During five years, we evaluated 21 patients with 21 giant hepatic cavernous hemangiomas with computed helical and multislice tomography. We included 18 women (86%) and 3 men (14%) with a mean age of 45 years. Results: The mean size of hemangiomas was 10.4 cm. Non enhanced computed tomography Showed 21 hemangiomas with lower density than adjacent hepatic parenchyma , all hemangiomas showed a central cleft area with low density. None hemangioma showed calcifications neither internal septa. In enhanced helical tomography all lesions demonstrated a globular, peripheral enhancing pattern with centripetal filling that begin in the arterial phase and continued in portal and delayed phases. None of the lesions showed complete filling. Conclusion: giant hepatic cavernous hemangiomas showed low attenuation in non enhanced computed tomography. central cleft area was very frequently seen. The enhancement pattern is characteristic, starting at the periphery with centripetal filling but it was never complete.

  18. Positron tomography. Methodology and applications

    International Nuclear Information System (INIS)

    Kellershohn, C.; Comar, D.

    1979-01-01

    Whereas single photon tomography provides a new and rewarding dimension to conventional nuclear medicine, positron tomography makes a new original approach possible of the analysis in vivo of fundamental biological and physiological processes. The main object of both is the sectional representation of the distribution of a radioactive indicator injected into the body system; compared with conventional detectors (gamma cameras and scintigraphic systems) they provide much greater accuracy in localization. The characteristics of these two methods can be presented schematically by comparing their respective advantages and drawbacks [fr

  19. UT-CT: A National Resource for Applications of High-Resolution X-ray Computed Tomography in the Geological Sciences

    Science.gov (United States)

    Carlson, W. D.; Ketcham, R. A.; Rowe, T. B.

    2002-12-01

    An NSF-sponsored (EAR-IF) shared multi-user facility dedicated to research applications of high-resolution X-ray computed tomography (CT) in the geological sciences has been in operation since 1997 at the University of Texas at Austin. The centerpiece of the facility is an industrial CT scanner custom-designed for geological applications. Because the instrument can optimize trade-offs among penetrating ability, spatial resolution, density discrimination, imaging modes, and scan times, it can image a very broad range of geological specimens and materials, and thus offers significant advantages over medical scanners and desktop microtomographs. Two tungsten-target X-ray sources (200-kV microfocal and 420-kV) and three X-ray detectors (image-intensifier, high-sensitivity cadmium tungstate linear array, and high-resolution gadolinium-oxysulfide radiographic line scanner) can be used in various combinations to meet specific imaging goals. Further flexibility is provided by multiple imaging modes: second-generation (translate-rotate), third-generation (rotate-only; centered and variably offset), and cone-beam (volume CT). The instrument can accommodate specimens as small as about 1 mm on a side, and as large as 0.5 m in diameter and 1.5 m tall. Applications in petrology and structural geology include measuring crystal sizes and locations to identify mechanisms governing the kinetics of metamorphic reactions; visualizing relationships between alteration zones and abundant macrodiamonds in Siberian eclogites to elucidate metasomatic processes in the mantle; characterizing morphologies of spiral inclusion trails in garnet to test hypotheses of porphyroblast rotation during growth; measuring vesicle size distributions in basaltic flows for determination of elevation at the time of eruption to constrain timing and rates of continental uplift; analysis of the geometry, connectivity, and tortuosity of migmatite leucosomes to define the topology of melt flow paths, for numerical

  20. Reproducibility in the assessment of acute pancreatitis with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Freire Filho, Edison de Oliveira; Vieira, Renata La Rocca; Yamada, Andre Fukunishi; Shigueoka, David Carlos; Bekhor, Daniel; Freire, Maxime Figueiredo de Oliveira; Ajzen, Sergio; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis]. E-mail: eofilho@ig.com.br; eoffilho@uol.com.br

    2007-11-15

    Objective: To evaluate the reproducibility of unenhanced and contrast-enhanced computed tomography in the assessment of patients with acute pancreatitis. Materials and methods: Fifty-one unenhanced and contrast-enhanced abdominal computed tomography studies of patients with acute pancreatitis were blindly reviewed by two radiologists (observers 1 and 2). The morphological index was separately calculated for unenhanced and contrast-enhanced computed tomography and the disease severity index was established. Intraobserver and interobserver reproducibility of computed tomography was measured by means of the kappa index ({kappa}). Results: Interobserver agreement was {kappa} 0.666, 0.705, 0.648, 0.547 and 0.631, respectively for unenhanced and contrast-enhanced morphological index, presence of pancreatic necrosis, pancreatic necrosis extension, and disease severity index. Intraobserver agreement (observers 1 and 2, respectively) was {kappa} = 0.796 and 0.732 for unenhanced morphological index; {kappa} 0.725 and 0.802 for contrast- enhanced morphological index; {kappa} = 0.674 and 0.849 for presence of pancreatic necrosis; {kappa} = 0.606 and 0.770 for pancreatic necrosis extension; and {kappa} = 0.801 and 0.687 for disease severity index at computed tomography. Conclusion: Computed tomography for determination of morphological index and disease severity index in the staging of acute pancreatitis is a quite reproducible method. The absence of contrast- enhancement does not affect the computed tomography morphological index reproducibility. (author)

  1. Medullary sponge kidney on axial computed tomography

    International Nuclear Information System (INIS)

    Ginalski, J.-M.; Schnyder, Pierre; Portmann, Luc; Jaeger, Philippe

    1991-01-01

    To evaluate features of medullary sponge kidney (MSK) on computed tomography (CT), 4-mm-thick axial slices without intravenous contrast material were 1st made in 13 patients through 24 kidneys which showed images of MSK on excretory urograms. On CT, papillary calcifications were found in 11 kidneys. In 5 of these, the calcifications were not detectable on plain films. Some hyperdense papillae (attenuation value 55-70 Hounsfield units) without calcification were found in 4 other kidneys. 9 kidneys appeared normal. 10 of the 14 kidneys were reexamined by a 2nd series of 4-mm-thick axial slices, 5 min after intravenous injection of 50 ml of Urografin. Images suggesting possible ectasia of precaliceal tubules were found in only 4 kidneys. These images appear much less obvious and characteristic on CT than on excretory urogram and do nothing more than suggest the possibility of MSK. In conclusion, the sensitivity of CT in the detection of MSK is markedly lower than that of excretory urography. In the most florid cases of the disease, CT can only show images suggesting the possibility of MSK. On the other hand, CT appears much more sensitive than plain films and tomograms of excretory in the detection of papillary calcifications, the most frequent complication of MSK. (author). 13 refs.; 3 figs

  2. Development of quantitative computed tomography lung protocols.

    Science.gov (United States)

    Newell, John D; Sieren, Jered; Hoffman, Eric A

    2013-09-01

    The purpose of this review article is to review the process of developing optimal computed tomography (CT) protocols for quantitative lung CT (QCT). In this review, we discuss the following important topics: QCT-derived metrics of lung disease; QCT scanning protocols; quality control; and QCT image processing software. We will briefly discuss several QCT-derived metrics of lung disease that have been developed for the assessment of emphysema, small airway disease, and large airway disease. The CT scanning protocol is one of the most important elements in a successful QCT. We will provide a detailed description of the current move toward optimizing the QCT protocol for the assessment of chronic obstructive pulmonary disorder and asthma. Quality control of CT images is also a very important part of the QCT process. We will discuss why it is necessary to use CT scanner test objects (phantoms) to provide frequent periodic checks on the CT scanner calibration to ensure precise and accurate CT numbers. We will discuss the use of QCT image processing software to segment the lung and extract the desired QCT metrics of lung disease. We will discuss the practical issues of using this software. The data obtained from the image processing software are then combined with those from other clinical examinations, health status questionnaires, pulmonary physiology, and genomics to increase our understanding of obstructive lung disease and improve our ability to design new therapies for these diseases.

  3. X-ray tubes for computed tomography

    International Nuclear Information System (INIS)

    Kotabe, Munenori; Sado, Noriyuki; Tachiki, Shigeru; Kitsuya, Minoru

    1979-01-01

    The X-ray tomography by computer processing (CT) is rapidly spreading because of the capabilities to obtain useful diagnostic information quantitatively, which was not able to be obtained by conventional X-ray photography, and to perform no-intrusion inspection, because it can picture the difference of X-ray absorption coefficient of several per cent in the soft tissues inside craniums. As the X-ray tubes to meet these requirements, the fixed anode X-ray tubes having high continuous rating are required for head CT, while the rotary anode X-ray tubes having the large cumulative heat capacity of anodes for whole body CT. Hitachi Ltd. has developed the X-ray tubes of type H 7129 of 4 kW rating for head CT and of type UJ-6FC-05V of 300 kHU (heat unit) for whole body CT. The specifications required for respective X-ray tubes include several items, and the maximum working tube voltage, focusing dimensions, long or short term maximum input and others are reported for the above described tubes. The performance centering around the loading life-time is described. In the tubes for whole body CT, repeated loading is also investigated. For the assumed input of 70,000 HU/slice, repeated loading of 10 times or more is possible in both cases when the input is repeatedly applied at loading intervals of 90 and 120 sec. (Wakatsuki, Y.)

  4. Computed tomography of the mediastinal tumor

    International Nuclear Information System (INIS)

    Tohyama, Junko; Kono, Michio; Tauchi, Taneyasu; Mizutani, Masako; Mizutani, Hirokazu

    1984-01-01

    Forty-one cases of mediastinal tumor examined by computed tomography were reviewed. CT findings of the mediastinal malignancy were as follows: 1) inhomogeneous density on contrast CT, 2) equivocaton of fat plane surrounding the tumor, 3) irregular margin. Benign teratoma had smooth margin and included fat or calcification density. Mediastinal seminoma was observed as a lobulated mass with no calcification on CT. These findings were similar to the patterns of malignant thymoma or lymphoma. Consequently, it was very difficult to differentiate between malignant thymoma and malignant lymphoma by CT. According to our data, malignant thymoma tended to expand to only one side of the anterior mediastinum and to invade the anterior chest wall. On the other hand, malignant lymphoma of anterior medistinal type expanded into the trachea and the superior vena cava. In patients with sarcoidosis, the enlargement of bilateral hilar lymph nodes was commonly observed, on the contrary, unilateral hilar lymph nodes enlargement was recognized in some cases of malignant lymphoma. (author)

  5. Portable Digital Radiography and Computed Tomography Manual

    Energy Technology Data Exchange (ETDEWEB)

    2007-11-01

    This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

  6. Computed Tomography Following Body Stuffing Heroin

    Directory of Open Access Journals (Sweden)

    Sean P. Nordt

    2015-12-01

    Full Text Available A 37-year-old male presented to the emergency department (ED in police custody for “medical clearance” before being taken to jail. The patient was approached by police officers for suspicion of selling illicit drugs. When approached by police he ran away and was witnessed to swallow several small plastic baggies suspected to contain heroin. He was apprehended and brought to the ED. On arrival, he was asymptomatic with a blood pressure 144/83mmHg, heart rate 67bpm, respiratory rate of 19bpm, oxygen saturation of 99% on room air and afebrile. A Glasgow coma score was 15 and he was alert and oriented to person, place and time. Patient had a negative review of systems. On physical examination pupils were 4mm and reactive to light, lungs clear to auscultation and had normal respiratory rate with normal cardiovascular exam. Abdomen was soft, non-tender and non-distended with present bowel sounds. The patient admitted to ingesting approximately 20 packets of heroin to avoid being charged with possession. The patient declined activated charcoal and whole bowel irrigation (WBI with polyethylene glycol-electrolyte solution (PEG-ELS. The patient declined a urine toxicology immunoassay screen. A computed tomography (CT of his abdomen with contrast was obtained and read as normal except for a cluster of foreign bodies within the distal stomach likely contained within a plastic bag.

  7. Computed tomography in diagnosis of hepatic abscess

    International Nuclear Information System (INIS)

    Sui, Osamu; Kurooka, Nobuyuki; Shirono, Ryozo

    1984-01-01

    Fourteen patients with hepatic abscess were evaluated by computed tomography (CT), who underwent surgical drainage. Eight cases were due to biliary tract infection and two were due to pylephlebitis of portal vein. Four cases were cryptogenic. Hepatic abscesses tended to be located in the right lobe of the liver. All of them appeared as low-density areas on plain CT scans and most of them were smooth-marginated and well-circumscribed. We classified the CT findings of the hepatic abscesses into three types; type 1: homogeneous low-density area, type 2: inhomogeneous low-density area, type 3: low-density mass surrounded by poorly-circumscribed low attenuation value area. In type 3 of the hepatic abscesses, poorly-circumscribed low attenuation value area was enhanced after the i.v. injection of contrast medium and was nearly imperceptible. Type 3 was thought to be characteristic of the hepatic abscess. Other CT findings such as pneumobilia, intrahepatic ductal stone, cholecystolithiasis and so on were also useful for the diagnosis of the hepatic abscess. (author)

  8. Computed tomography in diagnosis of hepatic abscess

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Osamu; Kurooka, Nobuyuki; Shirono, Ryozo (Tokushima Univ. (Japan). School of Medicine)

    1984-10-01

    Fourteen patients with hepatic abscess were evaluated by computed tomography (CT), who underwent surgical drainage. Eight cases were due to biliary tract infection and two were due to pylephlebitis of portal vein. Four cases were cryptogenic. Hepatic abscesses tended to be located in the right lobe of the liver. All of them appeared as low-density areas on plain CT scans and most of them were smooth-marginated and well-circumscribed. We classified the CT findings of the hepatic abscesses into three types; type 1: homogeneous low-density area, type 2: inhomogeneous low-density area, type 3: low-density mass surrounded by poorly-circumscribed low attenuation value area. In type 3 of the hepatic abscesses, poorly-circumscribed low attenuation value area was enhanced after the i.v. injection of contrast medium and was nearly imperceptible. Type 3 was thought to be characteristic of the hepatic abscess. Other CT findings such as pneumobilia, intrahepatic ductal stone, cholecystolithiasis and so on were also useful for the diagnosis of the hepatic abscess.

  9. Computed tomography dose assessment - a practical approach

    International Nuclear Information System (INIS)

    Leitz, W.; Szendro, G.; Axelsson, B.

    1995-01-01

    A survey of the pattern and frequency of computed tomography (CT) examinations in Sweden has been conducted covering 89 of the 90 existing CT scanners (in 1991). The radiation output and the absorbed doses in phantoms have been measured for all types of CT scanners. For the assessment of the effective dose to the patient a new, practical approach has been developed. The average absorbed doses measured in cylindrical PMMA phantoms were assumed to be valid also for patients, those in the 320 mm diameter phantom for the trunk region and those in the 160 mm diameter phantom for the neck and head. With guidance from the ICRP 60 concept of tissue weighting factors, average weighting factors were adopted for the trunk, the neck, and the head region. Effective patient doses were calculated using three factors for doses measured in phantoms with the settings of exposure parameters as recorded in the survey. The results were compared with dose evaluations based on Monte Carlo calculations. The agreement was found to be satisfactory. It is suggested that this new practical approach should be adopted as a standard method for the assessment of effective dose in CT practices thus enabling direct access to dose evaluations in daily clinical practice -a prerequisite for the implementation of radiation protection concepts into the radiological society. (Author)

  10. Computed tomography findings in pancreas divisum

    International Nuclear Information System (INIS)

    Lindstroem, E.; Ihse, I.

    1989-01-01

    In 29 patients with abdominal pain the diagnosis of pancreas divisum (PD) was verified by endoscopic retrograde pancreatography (EPR) via both the major and the minor papilla. Computed tomography (CT) was done in all patients to evaluate contour, volume, antero-posterior diameters and attenuation values of the gland in comparison with a normal reference series. Also, the validity of the CT grading of pancreatitis was assessed in comparison with ERP grading. Patients with PD had an increased cranio-caudal diameter of the pancreatic head (p<0.001). Further, the main pancreatic duct was visualized more often in patients with PD (p<0.01), who also had an increasing frequency of pancreatic calcifications (p<0.05). Otherwise there were no differences compared with the normal series. The observed reduction in the volume of the gland in patients with marked pancreatitis at ERP seemingly reflected the severity of inflammation. No cleavage between the dorsal and ventral anlage was identified. CT was found to be too unspecific to be of any use in grading of pancreatitis. In conclusion, CT findings in patients with PD are sparse, unspecific and preferably a reflection of pancreatitis, if present. ERP remains the ''gold standard'' for the diagnosis. (orig.)

  11. X-ray diffraction computed tomography

    International Nuclear Information System (INIS)

    Harding, G.; Kosanetzky, J.; Neitzel, U.

    1987-01-01

    Coherent scattering of x-ray photons leads to the phenomenon of x-ray diffraction, which is widely used for determining atomic structure in materials science. A technique [x-ray diffraction computed tomography (CT)] is described, analogous to conventional CT, in which the x-ray diffraction properties of a stack of two-dimensional object sections may be imaged. The technique has been investigated using a first generation (single pencil beam) CT scanner to measure small angle coherent scatter, in addition to the customary transmitted radiation. Diffraction data from a standard CT performance phantom obtained with this new technique and with an x-ray diffractometer are compared. The agreement is satisfactory bearing in mind the poor momentum resolution of our apparatus. The dose and sensitivity of x-ray diffraction CT are compared with those of conventional transmission CT. Diffraction patterns of some biological tissues and plastics presented in a companion paper indicate the potential of x-ray diffraction CT for tissue discrimination and material characterization. Finally, possibilities for refinement of the technique by improving the momentum resolution are discussed

  12. Gradient computation for VTI acoustic wavefield tomography

    KAUST Repository

    Li, Vladimir

    2016-09-06

    Wavefield tomography can handle complex subsurface geology better than ray-based techniques and, ultimately, provide a higher resolution. Here, we implement forward and adjoint wavefield extrapolation for VTI (transversely isotropic with a vertical symmetry axis) media using a pseudospectral operator that employes a separable approximation of the P-wave dispersion relation. This operator is employed to derive the gradients of the differential semblance optimization (DSO) and modified stack-power objective functions. We also obtain the gradient expressions for the data-domain objective function, which can incorporate borehole information necessary for stable VTI velocity analysis. These gradients are compared to the ones obtained with a space-time finite-difference (FD) scheme for a system of coupled wave equations. Whereas the kernels computed with the two wave-equation operators are similar, the pseudospectral method is not hampered by the imprint of the shear-wave artifact. Numerical examples also show that the modified stack-power objective function produces cleaner gradients than the more conventional DSO operator.

  13. Computed tomography in acute ischemic stroke

    International Nuclear Information System (INIS)

    Loevblad, Karl-Olof; Baird, Alison E.

    2010-01-01

    Stroke remains the third most important cause of mortality in industrialized countries; this has prompted research for improvements in both diagnostic and therapeutic strategies for patients with signs of acute cerebral ischemia. Over the last decade, there has been a parallel in progress in techniques in both diagnostic and therapeutic options. While previously only used for excluding hemorrhage, imaging now has the possibility to detect ischemia, vascular occlusion, as well as detect tissue at risk in one setting. It should also allow to monitor treatment and predict/exclude therapeutic complications. Parallel to advances in magnetic resonance imaging of stroke, computed tomography has improved immensely over the last decade due to the development of CT scanners that are faster and that allow to acquire studies such as CT perfusion or CT angiography in a reliable way. CT can detect many signs that might help us detect impending signs of massive infarction, but we still lack the experience to use these alone to prevent a patient from benefitting from possible therapy. (orig.)

  14. Diagnosis of choledocholithiasis by computed tomography

    International Nuclear Information System (INIS)

    Lee, Jae Sub; Kang, Kyung Sook; Lee, Yul; Chung, Soo Young; Bae, Sang Hoon; Yoon, Jong Sup

    1986-01-01

    In order to determine the value of Computed Tomography (CT) in the diagnosis of choledocholithiasis, the authors retrospectively studied 33 cases of choledocholithiasis proven by surgery from January 1983 to June 1985. Among them, 15 cases were examined by both CT and ultrasonography. The results were as follows: 1. There were 12 men and 21 women with mean age of 57 years. 2. CT correctly diagnosed choledocholithiasis in 29(88%) of total 33 cases. There were 4 false negative diagnoses and there were no false positive. 3. In 15 cases which were examined by both CT and ultrasonography, 13(86%) cases were correctly diagnosed by CT and 7(46%) by ultrasonography. 4. The majority (88%) of choledocholithiasis were demonstrated as calcific density and 4 cases (12%) were nearly isotense to pancreas. 5. Most cases were shown as homogenous density and 5 cases (16%) as ringlike structure with low density center and high density periphery. 6. Additional findings, such as intrahepatic and/or GB stones, paricholangitic abscess, GB empyema, ascites, and liver cirrhosis were also identified by CT. 7. CT is effective for noninvasive and accurate detection of choledocholithiasis. So invasive cholangiography, such as E.R.C.P or P.T.C can be reserved in many cases of choledocholithiasis.

  15. Diagnosis of choledocholithiasis by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sub; Kang, Kyung Sook; Lee, Yul; Chung, Soo Young; Bae, Sang Hoon; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1986-02-15

    In order to determine the value of Computed Tomography (CT) in the diagnosis of choledocholithiasis, the authors retrospectively studied 33 cases of choledocholithiasis proven by surgery from January 1983 to June 1985. Among them, 15 cases were examined by both CT and ultrasonography. The results were as follows: 1. There were 12 men and 21 women with mean age of 57 years. 2. CT correctly diagnosed choledocholithiasis in 29(88%) of total 33 cases. There were 4 false negative diagnoses and there were no false positive. 3. In 15 cases which were examined by both CT and ultrasonography, 13(86%) cases were correctly diagnosed by CT and 7(46%) by ultrasonography. 4. The majority (88%) of choledocholithiasis were demonstrated as calcific density and 4 cases (12%) were nearly isotense to pancreas. 5. Most cases were shown as homogenous density and 5 cases (16%) as ringlike structure with low density center and high density periphery. 6. Additional findings, such as intrahepatic and/or GB stones, paricholangitic abscess, GB empyema, ascites, and liver cirrhosis were also identified by CT. 7. CT is effective for noninvasive and accurate detection of choledocholithiasis. So invasive cholangiography, such as E.R.C.P or P.T.C can be reserved in many cases of choledocholithiasis.

  16. Renal imaging diagnosis by computed tomography

    International Nuclear Information System (INIS)

    Nishitani, Hiromu

    1984-01-01

    The sizes of the kidneys of 96 persons without known renal diseases were measured using computed tomography. The average renal length consisted of 10 transverse sections, each 10 mm thick, with a standard deviation of 1 such section. The mean renal width was 61 +- 6.8 mm on the left, and 64 +- 6.4 mm on the right. The mean renal thickness was 51 +- 6.1 mm on the left, and 49 +- 6.9 mm on the right. The renal parenchyma averaged 14 +- 2.2 mm in thickness, regardless of side or sex. Measurement errors were estimated to be approximately 10 percent. There were no significant differences in renal length according to CT and angiography. Renal measurements determined by CT are useful in predicting vital kidney sizes. The CT findings among 114 patients with various renal diseases were compared with results of their excretory urographic and/or angiographic studies. In nearly all instances, CT was superior to excretory urography in detecting renal diseases. It was unnecessary to confirm renal abnormalities detected by CT using excretory urography. CT compared favorably with angiography in the definitive diagnostic imaging and staging of renal cell carcinomas. CT is destined to play an important role in the diagnostic imaging of renal diseases. (author)

  17. Ruptured ectopic pregnancy diagnosed with computed tomography

    International Nuclear Information System (INIS)

    Michalak, Maciej; Żurada, Anna; Biernacki, Maciej; Zygmunt, Kozielec

    2010-01-01

    The rupture of ectopic pregnancy (EP) still remains the primary and direct cause of death in the first trimester of pregnancy. Ultrasonography is known to be a modality of choice in EP diagnostics. We found a severe discrepancy between the frequency of ectopic pregnancies (EP) and the number of available computed tomography (CT) examinations. A 29-year-old woman was admitted to the emergency department with a history of abdominal pain, nausea, vomiting and collapse. Sonographic findings of a suspected EP were unclear. Moreover, not all features of intrauterine pregnancy were present. Due to the patient’s life-threatening condition, an emergency multi-slice CT with MPR and VRT reconstructions was performed, revealing symptoms of a ruptured EP. In the right adnexal area, a well-vascularized, solid-cystic abnormal mass lesion was found. Intraperitoneal hemorrhage was confirmed intraoperatively, and the right fallopian tube with a tubal EP was resected. In the surgery in situ, as well as in the pathological examination of the tumor mass, a human embryo of approximately 1.5 cm in length (beginning of the 8 th week of gestation) was found. Although ultrasonography still remains the first-line imaging examination in EP diagnostics, sometimes the findings of suspected EPs are unclear and not sufficient. The rupture of EP, with serious bleeding and symptoms of shock, may require an emergent pelvic and abdominal CT inspection. A clear correlation was found between the macroscopic CT images and the intraoperatively sampled material

  18. Computer tomography and urinary calculi, 2

    International Nuclear Information System (INIS)

    Kageyama, Shizuichi; Kuwahara, Masaaki; Kurosu, Seiichi; Orikasa, Seiichi

    1986-01-01

    To find whether computer tomography (CT) can determine the composition of urinary calculi, we measured the CT values of 47 calculi in vitro and 26 calculi in situ. The results are as follows; 1) CT values (Hounsfield Unit) of various stones which were measured in vitro (mean ± s.d.) were as follows; mixed calcium oxalate and calcium phosphate (the mixed stone) 1555 ± 193 H, magnecium ammonium phosphate (MAP) 1285 ± 248 H, cystine 757 ± 114 H, uric acid 480 H. 2) In situ the peak CT values of various calculi were almost the same as those in vitro, but the mean CT values were slightly less. 3) From these results we concluded that cystine and uric acid stones can be identified by the CT value. With regard to the mixed stone and MAP, it is almost impossible to identify these stones especially when they reveal the CT values of 1100 - 1500 H. However, stones with the peak CT values of more than 1500 H were rarely MAP and often the mixed stone, and those with the mean CT values of 1000 - 1100 H were rarely the mixed stone and often MAP. (author)

  19. Advanced proton imaging in computed tomography.

    Science.gov (United States)

    Mattiazzo, S; Bisello, D; Giubilato, P; Pantano, D; Pozzobon, N; Snoeys, W; Wyss, J

    2015-09-01

    In recent years the use of hadrons for cancer radiation treatment has grown in importance, and many facilities are currently operational or under construction worldwide. To fully exploit the therapeutic advantages offered by hadron therapy, precise body imaging for accurate beam delivery is decisive. Proton computed tomography (pCT) scanners, currently in their R&D phase, provide the ultimate 3D imaging for hadrons treatment guidance. A key component of a pCT scanner is the detector used to track the protons, which has great impact on the scanner performances and ultimately limits its maximum speed. In this article, a novel proton-tracking detector was presented that would have higher scanning speed, better spatial resolution and lower material budget with respect to present state-of-the-art detectors, leading to enhanced performances. This advancement in performances is achieved by employing the very latest development in monolithic active pixel detectors (to build high granularity, low material budget, large area silicon detectors) and a completely new proprietary architecture (to effectively compress the data). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Computed tomography of the alveolar bone

    International Nuclear Information System (INIS)

    Schueller, H.

    1996-01-01

    In addition to the conventional radiological methods used in odontology, computed tomography (CT) provides superposition-free images of the mandible and maxilla. Its value has been proved not only in cases of malignancy but also in many other problems. If an examination is performed with a slice thickness of less than 1.5 mm, the form and position of retained teeth in the alveolar bone, as well as subsequent lesions of neighboring permanent teeth, can be visualized so that early treatment can be planned. If the parodontal space of a retained tooth is visible, orthodontic intervention is possible. Precise assessment of horizontal or vertical bone loss is essential in inflammatory dental diseases. The morphology and extent of benign cystic lesions are also shown by CT. With CT surgical strategy of an intended implant therapy can take into account the remaining bone substance and the exact position of nerves and foramina. If such therapy is possible, the location, form and number of implants are easily defined. (orig.) [de

  1. Image quality in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Gerke, Oke; Thygesen, Jesper

    2018-01-01

    Background Computed tomography (CT) technology is rapidly evolving and software solution developed to optimize image quality and/or lower radiation dose. Purpose To investigate the influence of adaptive statistical iterative reconstruction (ASIR) at different radiation doses in coronary CT...... angiography (CCTA) in detailed image quality. Material and Methods A total of 160 CCTA were reconstructed as follows: 55 scans with filtered back projection (FBP) (650 mA), 51 scans (455 mA) with 30% ASIR (ASIR30), and 54 scans (295 mA) with 60% ASIR (ASIR60). For each reconstruction, subjective image quality...... was assessed by five independent certified cardiologists using a visual grading analysis (VGA) with five predefined image quality criteria consisting of a 5-point scale. Objective measures were contrast, noise, and contrast-to-noise ratio (CNR). Results The CTDIvol resulted in 10.3 mGy, 7.4 mGy, and 4.6 m...

  2. Computed tomography of lacrimal fossa tumors

    International Nuclear Information System (INIS)

    Park, Chan Sup; Kim, Young Goo; Chang, Kee Hyun

    1985-01-01

    The lacrimal fossa can be involved by a wide spectrum of orbital pathology. The correct diagnosis is important to avoid unnecessary procedure and to do appropriate management. 14 patients with mass lesions in the lacrimal fossa were evaluated with computed tomography (CT) and clinical findings. The results were as follows: 1. Final diagnosis of 14 cases with lacrimal fossa tumors was pleomorphic adenoma in 3 cases, adenoid cystic carcinoma in 1 case, pseudotumor in 5 cases, lymphoma in 2 cases, neurofibroma in 1 case, chloroma in 1 case and metastatic adenocarcinoma in 1 case. 2. The duration of symptoms of pleomorphic adenoma was more than 1 year and characteristic CT findings were globular masses with pressure erosion of the adjacent bone. Patient with adenoid cystic carcinoma had a short history of symptoms. CT showed a fusiform mass but intracranial extension with frank destruction of sphenoid bone. 3. Patients with pseudotumor and lymphoma had symptoms for less than 1 year. The CT findings were ill-defined infiltrative patterns with scleral thickening and the differential diagnosis of them was difficult. 4. The margins of neurofibroma and chloroma were well defined while that of the metastic adenocarcinoma was ill-defined. 5. The degree and the extent of the contrast enhancement gave no benefit in the differential diagnosis of each disease entities and even of the benign and malignant lesions

  3. Application of Genetic Algorithms in Seismic Tomography

    Science.gov (United States)

    Soupios, Pantelis; Akca, Irfan; Mpogiatzis, Petros; Basokur, Ahmet; Papazachos, Constantinos

    2010-05-01

    application of hybrid genetic algorithms in seismic tomography is examined and the efficiency of least squares and genetic methods as representative of the local and global optimization, respectively, is presented and evaluated. The robustness of both optimization methods has been tested and compared for the same source-receiver geometry and characteristics of the model structure (anomalies, etc.). A set of seismic refraction synthetic (noise free) data was used for modeling. Specifically, cross-well, down-hole and typical refraction studies using 24 geophones and 5 shoots were used to confirm the applicability of the genetic algorithms in seismic tomography. To solve the forward modeling and estimate the traveltimes, the revisited ray bending method was used supplemented by an approximate computation of the first Fresnel volume. The root mean square (rms) error as the misfit function was used and calculated for the entire random velocity model for each generation. After the end of each generation and based on the misfit of the individuals (velocity models), the selection, crossover and mutation (typical process steps of genetic algorithms) were selected continuing the evolution theory and coding the new generation. To optimize the computation time, since the whole procedure is quite time consuming, the Matlab Distributed Computing Environment (MDCE) was used in a multicore engine. During the tests, we noticed that the fast convergence that the algorithm initially exhibits (first 5 generations) is followed by progressively slower improvements of the reconstructed velocity models. Thus, to improve the final tomographic models, a hybrid genetic algorithm (GA) approach was adopted by combining the GAs with a local optimization method after several generations, on the basis of the convergence of the resulting models. This approach is shown to be efficient, as it directs the solution search towards a model region close to the global minimum solution.

  4. Computed tomography of the breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Soo Young; Lee, Yul; Bae, Sang Hoon; Yoon, Jong Sup; Lee, Ki Chu [Hallym University Medical Center, Seoul (Korea, Republic of)

    1985-12-15

    The indication of computed tomography for the breast lesion are 1) Unusually extensive or small breast caused technical difficulties in performing mammograms. 2) Questionable mammographic findings, especially in dense proliferative breast parenchyme. 3) Microcancer. 4) Suspicious regional lymph node enlargement or invasive of the chest wall by breast cancer. The diagnosis of breast CT in breast cancer is based on pathologic anatomic changes and characteristic increase of mean CT No. of lesion following contrast enhancement. Authors analysed CT of the 34 patients who were clinically suspected breast cancer, and compared with mammography. The results are as follows: 1. Pathological diagnosis of 34 cases were 27 cases of breast cancer, 4 cases of fibrocystic disease, 2 cases of fibroadenoma, and 1 case of intraductal papilloma. The diagnostic accuracy of CT in 27 breast cancer was 93% (25 cases) and mammography 71% (19 case). 2. Correct diagnosis of CT in 7 benign breast disease is in 5 cases and mammography in 5 cases. 3. The most important finding of CT in breast cancer is characteristic increase of CT No. of lesion following contrast enhancement (200 ml, 65%): over average 50 HU in 19 cases of 27 breast cancers, 30-50 HU in a 6 cases, 20-30 HU in 2 cases with tumor necrosis. 4. Computed with mammography, other more valuable CT findings of breast cancer are axillary lymph node enlargement and adjacentic pectoral muscle invasion. 5. In conclusion, breast CT is considered as valuable diagnostic tool in evaluation of breast cancer, but not of benign breast disease.

  5. Computer stress study of bone with computed tomography

    International Nuclear Information System (INIS)

    Linden, M.J.; Marom, S.A.; Linden, C.N.

    1986-01-01

    A computer processing tool has been developed which, together with a finite element program, determines the stress-deformation pattern in a long bone, utilizing Computed Tomography (CT) data files for the geometry and radiographic density information. The geometry, together with mechanical properties and boundary conditions: loads and displacements, comprise the input of the Finite element (FE) computer program. The output of the program is the stresses and deformations in the bone. The processor is capable of developing an accurate three-dimensional finite element model from a scanned human long bone due to the CT high pixel resolution and the local mechanical properties determined from the radiographic densities of the scanned bone. The processor, together with the finite element program, serves first as an analysis tool towards improved understanding of bone function and remodelling. In this first stage, actual long bones may be scanned and analyzed under applied loads and displacements, determined from existing gait analyses. The stress-deformation patterns thus obtained may be used for studying the biomechanical behavior of particular long bones such as bones with implants and with osteoporosis. As a second stage, this processor may serve as a diagnostic tool for analyzing the biomechanical response of a specific patient's long long bone under applied loading by utilizing a CT data file of the specific bone as an input to the processor with the FE program

  6. Diagnosis of hoof disease in horses using computed tomography

    Directory of Open Access Journals (Sweden)

    Kovač Milomir

    2002-01-01

    Full Text Available This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Germany of 39 horses with hoof diseaseas. The most frequently findings were the navicular syndrome (eight horses, laminitis (seven horses, keratnoma (six horses and ossification of collateral cartilages in the distal phalanx (four horses. The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnose in five horses. In four of horses no pathologic changes of the hoof were determined by computed tomography.

  7. Diagnosis of hoof diseases in horses using computed tomography

    International Nuclear Information System (INIS)

    Kovac, M.; Nowak, M.; Kaufels, N.; Tambur, Z.

    2002-01-01

    This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Bergische Tierklinik), Germany, of 39 horses with hoof diseases. The most frequently findings were the navicular syndrome (eight horses), laminitis (seven horses), keratnoma (six horses) and ossification of collateral cartilages in the distal phalanx (four horses). The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnose in five horses. In four of horses no pathologic changes of the hoof were determined by computed tomography

  8. Diffuse abnormalities of the trachea: computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@gmail.com; Pozes, Aline Serfaty [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Escola de Medicina. Dept. de Radiologia; Escuissato, Dante Luiz [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Radiologia; Irion, Klaus Loureiro [The Cardiothoracic Centre NHS Trust, Liverpool (United Kingdom); Araujo Neto, Cesar de [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Radiologia; Barillo, Jorge Luiz; Zanetti, Glaucia [Faculdade de Medicina de Petropolis (FMP), RJ (Brazil). Dept. de Cirurgia Clinica; Souza, Carolina Althoff [University of Ottawa, Ottawa, ON (Canada)

    2008-01-15

    The aim of this pictorial essay was to present the main computed tomography findings seen in diffuse diseases of the trachea. The diseases studied included amyloidosis, tracheobronchopathia osteochondroplastica, tracheobronchomegaly, laryngotracheobronchial papillomatosis, lymphoma, neurofibromatosis, relapsing polychondritis, Wegener's granulomatosis, tuberculosis, paracoccidioidomycosis, and tracheobronchomalacia. The most common computed tomography finding was thickening of the walls of the trachea, with or without nodules, parietal calcifications, or involvement of the posterior wall. Although computed tomography allows the detection and characterization of diseases of the central airways, and the correlation with clinical data reduces the diagnostic possibilities, bronchoscopy with biopsy remains the most useful procedure for the diagnosis of diffuse lesions of the trachea. (author)

  9. Computed tomography of the llama head: technique and normal anatomy

    International Nuclear Information System (INIS)

    Hathcock, J.T.; Pugh, D.G.; Cartee, R.E.; Hammond, L.

    1996-01-01

    Computed tomography was performed on the head of 6 normal adult llamas. The animals were under general anesthesia and positioned in dorsal recumbency on the scanning table. The area scanned was from the external occipital protuberance to the rostral portion of the nasal passage, and the images are presented in both a bone window and a soft tissue window to allow evaluation and identification of the anatomy of the head. Computed tomography of the llama head can be accomplished by most computed tomography scanners utilizing a technique similar to that used in small animals with minor modification of the scanning table

  10. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Vermelho, Marli Batista Fernandes; Correia, Ademir Silva; Michailowsky, Tania Cibele de Almeida; Suzart, Elizete Kazumi Kuniyoshi; Ibanes, Aline Santos; Almeida, Lanamar Aparecida; Khoury, Zarifa; Barba, Mario Flores, E-mail: marlivermelho@globo.com [Instituto de Infectologia Emilio Ribas (IIER), Sao Paulo, SP (Brazil)

    2015-03-15

    Objective: to evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and methods: retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. (author)

  11. Development of a guidance guide for dosimetry in computed tomography

    International Nuclear Information System (INIS)

    Fontes, Ladyjane Pereira

    2016-01-01

    Due to frequent questions from users of ionization chambers pencil type calibrated in the Instrument Calibration Laboratory of the Institute of Energy and Nuclear Research (LCI - IPEN), on how to properly apply the factors indicated in their calibration certificates, a guide was prepared guidance for dosimetry in computed tomography. The guide includes guidance prior knowledge of half value layer (HVL), as it is necessary to know the effective beam energy for application quality for correction factor (kq). The evaluation of HVL in TC scanners becomes a difficult task due to system geometry and therefore a survey was conducted of existing methodologies for the determination of HVL in clinical beams Computed Tomography, taking into account technical, practical and economic factors. In this work it was decided to test a Tandem System consists of absorbing covers made in the workshop of IPEN, based on preliminary studies due to low cost and good response. The Tandem system consists of five cylindrical absorbing layers of 1mm, 3mm, 5mm, 7mm and 10mm aluminum and 3 cylindrical absorbing covers 15mm, 25mm and acrylic 35mm (PMMA) coupled to the ionization chamber of commercial pencil type widely used in quality control tests in dosimetry in clinical beams Computed tomography. Through Tandem curves it was possible to assess HVL values and from the standard curve pencil-type ionization chamber, Kq find the appropriate beam. The elaborate Guide provides information on how to build the calibration curve on the basis of CSR, to find the Kq and information for construction Tandem curve, to find values close to CSR. (author)

  12. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Carina Mari Aparici

    2016-01-01

    Full Text Available We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  13. X-ray machine vision and computed tomography

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This survey examines how 2-D x-ray machine vision and 3-D computed tomography will be used in industry in the 1988-1995 timeframe. Specific applications are described and rank-ordered in importance. The types of companies selling and using 2-D and 3-D systems are profiled, and markets are forecast for 1988 to 1995. It is known that many machine vision and automation companies are now considering entering this field. This report looks at the potential pitfalls and whether recent market problems similar to those recently experienced by the machine vision industry will likely occur in this field. FTS will publish approximately 100 other surveys in 1988 on emerging technology in the fields of AI, manufacturing, computers, sensors, photonics, energy, bioengineering, and materials

  14. [Application of cone-beam computed tomography in the diagnosis and treatment of external root resorption of adjacent teeth caused by impacted teeth].

    Science.gov (United States)

    Li, Zhijin; Guo, Jiaping; Shi, Yongmei; Dong, Qingshan; Wang, Xiang; Xiong, Caihua; Gui, Xiao

    2013-12-01

    This study aims to investigate the diagnosis and treatment of external root resorption of adjacent teeth caused by impacted teeth via cone-beam computed tomography (CBCT). A total of 19 teeth from 15 patients with uncertain external root resorption caused by an adjacent impacted tooth were examined from January 2011 to December 2011. All teeth with uncertain external root resorption were scanned by CBCT. Three dimensions reconstruction were the conducted to determine the location and extent of resorption. In all cases, CBCT identified the accurate location and extent of external root resorption caused by adjacent impacted teeth. Furthermore, the technique provided impacted teeth location in three dimensions, including the relation between the impacted teeth and surrounding vital structures. CBCT can provide direct and accurate images of the location and extent of external root resorption, as well as the location of the adjacent impacted teeth in three dimensions. Therefore, the proposed technique provides reliable information for clinical diagnosis and treatment.

  15. Limitations of four-slice multirow detector computed tomography in the detection of coronary stenosis.

    Science.gov (United States)

    Martuscelli, Eugenio; Razzini, Cinzia; D'Eliseo, Alessia; Marchei, Massimo; Pisani, Eliana; Romeo, Francesco

    2004-02-01

    Our aim was to compare 4-slice spiral computed tomography with conventional coronary angiography in the detection of significant (> 50%) coronary stenosis. Sixty-two patients (41 males, 21 females, mean age 60 +/- 8 years) with suspected coronary artery disease were submitted to coronary angiography and then to multislice spiral computed tomography (GE Light Speed 4 slice) performed 12 +/- 5 days later. We excluded 25% of the patients from analysis because of a heart rate > 70 b/min or because of frequent ectopic beats. We also excluded from analysis 23% of all the angiographic segments judged not evaluable at multislice spiral computed tomography. Within these limits, the sensitivity was 65%, the specificity 98%, the positive predictive value 88%, and the negative predictive value 92%. By considering the intrinsic limitations such as its low temporal and spatial resolution, 4-slice spiral computed tomography has a limited applicability and has to be used with caution in the evaluation of native coronary arteries.

  16. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    Science.gov (United States)

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

  17. The Utility of Dual Energy Computed Tomography in Musculoskeletal Imaging

    Directory of Open Access Journals (Sweden)

    Sachin Khanduri

    2017-01-01

    Full Text Available The objective of this article is to review the mechanisms, advantages and disadvantages of dual energy computed tomography (DECT over conventional tomography (CT in musculoskeletal imaging as DECT provides additional information about tissue composition and artifact reduction. This provides clinical utility in detection of urate crystals, bone marrow edema, reduction of beam hardening metallic artifact, and ligament and tendon analysis.

  18. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle W

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...

  19. Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

    DEFF Research Database (Denmark)

    Engelmann, Bodil Elisabeth; Loft, Annika; Kjær, Andreas

    2014-01-01

    OBJECTIVES: Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence...

  20. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography in evaluation of residual intramuscular myxoma

    International Nuclear Information System (INIS)

    Zade, Anand; Ahire, Archana; Shetty, Shishir; Rai, Sujith; Bokka, Rajashekharrao; Velumani, Arokiaswamy; Kabnurkar, Rasika

    2015-01-01

    Intramuscular myxoma (IM) is a rare benign neoplasm. In a patient diagnosed with IM of left thigh, we report the utility of a postoperative fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scan in assessing the efficacy of surgical excision

  1. Endodontic practice management with cone-beam computed tomography

    Directory of Open Access Journals (Sweden)

    Priyank Sethi

    2017-01-01

    Full Text Available Traditionally, conventional periapical radiology formed the backbone of endodontics for diagnosis, treatment planning, and management. One of the major associated gripes being the technique created two-dimensional images of three-dimensional (3D structures, suffered magnification, superimposition, and distortion, leading to compromised diagnostic information. The need to analyze the area of interest in all the possible planes led to the introduction of cone-beam computed tomography (CBCT, a novel modality specifically designed to produce precise, undistorted 3D reconstructed images of the maxillofacial skeleton. CBCT is increasingly being embraced by various fields in dentistry, remarkably in endodontic practice. A systematic literature-based and book-based review was conducted using the keywords “CBCT in endodontics” and “endodontic applications of CBCT.” This article hereby discusses the prospects of CBCT in endodontics with an emphasis on its application in diagnosis and management along with treatment outcome assessment.

  2. Computed Tomography diagnosis of skeletal involvement in multiple myeloma

    International Nuclear Information System (INIS)

    Scutellari, Pier Nuccio; Galeotti, Roberto; Leprotti, Stefano; Piva, Nadia; Spanedda, Romedio

    1997-01-01

    The authors assess the role of Computed Topography in the diagnosis and management of multiple myeloma (MM) and investigate if Computed Tomography findings can influence the clinical approach, prognosis and treatment. 273 multiple myeloma patients submitted to Computed Tomography June 1994, to December, 1996. The patients were 143 men and 130 women (mean age: 65 years): 143 were stage I, 38 stage II and 92 stage III according to Durie and Salomon's clinical classification. All patients were submitted to blood tests, spinal radiography and Computed Tomography, the latter with serial 5-mm scans on several vertebral bodies. Computed Tomography despicted vertebral arch and process involvement in 3 cases with the vertebral pedicle sign. Moreover, Computed Tomography proved superior to radiography in showing the spread of myelomatous masses into the soft tissues in a case with solitary permeative lesion in the left public bone, which facilitated subsequent biopsy. As for extraosseous localizations, Computed Tomography demonstrated thoracic soft tissue (1 woman) and pelvic (1 man) involvement by myelomtous masses penetrating into surrounding tissues. In our series, only a case of osteosclerotic bone myeloma was observed in the pelvis, associated with lytic abnormalities. Computed Tomography findings do not seem to improve the clinical approach and therapeutic management of the disease. Nevertheless, the authors reccommend Computed Tomography for some myelomatous conditions, namely: a) in the patients with focal bone pain but normal skeletal radiographs; b) in the patients with M protein, bone marrow plasmocytosis and back pain, but with an incoclusive multiple myeloma diagnosis; c) to asses bone spread in the regions which are anatomically complex or difficult to study with radiography and to depict soft tissue involvement; d) for bone biopsy

  3. The Comparison of Computed Tomography Perfusion, Contrast-Enhanced Computed Tomography and Positron-Emission Tomography/Computed Tomography for the Detection of Primary Esophageal Carcinoma.

    Science.gov (United States)

    Genc, Berhan; Kantarci, Mecit; Sade, Recep; Orsal, Ebru; Ogul, Hayri; Okur, Aylin; Aydin, Yener; Karaca, Leyla; Eroğlu, Atilla

    2016-01-01

    The purpose of this study was to investigate the efficiency of computed tomography perfusion (CTP), contrast-enhanced computed tomography (CECT) and 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron-emission tomography (PET/CT) in the diagnosis of esophageal cancer. This prospective study consisted of 33 patients with pathologically confirmed esophageal cancer, 2 of whom had an esophageal abscess. All the patients underwent CTP, CECT and PET/CT imaging and the imaging findings were evaluated. Sensitivity, specificity and positive and negative predictive values were calculated for each of the 3 imaging modalities relative to the histological diagnosis. Thirty-three tumors were visualized on CTP, 29 on CECT and 27 on PET/CT. Six tumors were stage 1, and 2 and 4 of these tumors were missed on CECT and PET/CT, respectively. Significant differences between CTP and CECT (p = 0.02), and between CTP and PET/CT (p = 0.04) were found for stage 1 tumors. Values for the sensitivity, specificity and positive and negative predictive values on CTP were 100, 100, 100 and 100%, respectively. Corresponding values on CECT were 93.94, 0, 93.94 and 0%, respectively, and those on PET/CT were 87.88, 0, 93.55 and 0%, respectively. Hence, the sensitivity, specificity and positive and negative predictive values of CTP were better than those of CECT and PET/CT. CTP had an advantage over CECT and PET/CT in detecting small lesions. CTP was valuable, especially in detecting stage 1 tumors. © 2016 S. Karger AG, Basel.

  4. Computer aided stress analysis of long bones utilizing computer tomography

    International Nuclear Information System (INIS)

    Marom, S.A.

    1986-01-01

    A computer aided analysis method, utilizing computed tomography (CT) has been developed, which together with a finite element program determines the stress-displacement pattern in a long bone section. The CT data file provides the geometry, the density and the material properties for the generated finite element model. A three-dimensional finite element model of a tibial shaft is automatically generated from the CT file by a pre-processing procedure for a finite element program. The developed pre-processor includes an edge detection algorithm which determines the boundaries of the reconstructed cross-sectional images of the scanned bone. A mesh generation procedure than automatically generates a three-dimensional mesh of a user-selected refinement. The elastic properties needed for the stress analysis are individually determined for each model element using the radiographic density (CT number) of each pixel with the elemental borders. The elastic modulus is determined from the CT radiographic density by using an empirical relationship from the literature. The generated finite element model, together with applied loads, determined from existing gait analysis and initial displacements, comprise a formatted input for the SAP IV finite element program. The output of this program, stresses and displacements at the model elements and nodes, are sorted and displayed by a developed post-processor to provide maximum and minimum values at selected locations in the model

  5. Computed tomography in Duchenne type muscular dystrophy

    International Nuclear Information System (INIS)

    Kawai, Mitsuru; Kunimoto, Masanari; Motoyoshi, Yasufumi; Kuwata, Takashi; Nakano, Imaharu

    1985-01-01

    The computed tomography (CT) scan was performed on 91 Duchenne type muscular dystrophy (DMD) patients on the following four levels; (1) at the level of L3 vertebra, (2) 2-3cm above the symphysis pubica, (3) midposition of the thigh, (4) largest-diameter section of the lower leg. The CT of muscles common to most of the DMD patients were as follows: 1. Muscle atrophy: Muscle atrophy was shown as a reduction in the cross-sectional area of the muscles. Very mild muscle atrophy could be detected either by the clearly identified muscle border or by scattered low-density areas of so-called ''moth-eaten'' appearance within muscles. 2. Fat infiltration: The decrease in radio-density of muscles was interpreted as infiltration of fatty tissue. This type of density change was further classified into diffuse, streaked, cobblestone and salt-and-pepper patterns according to the spacial distribution of low-density areas. 3. Selectivity pattern: As the chronological sequence of DMD muscle degeneration is usually different among individual muscles, it may be seen, in some stages, that some of the synergistic muscles are still only slightly involved, while the others are quite severely atrophied with evident fat infiltration. In certain stages of the disease, most of the patients show relative preservation of particular muscles although they assumed a rounded shape. The most resistent muscle was musculus gracilis, followed by the musculus sartorius, musculus semitendinosus (and/or musculus semimembranosus) in that order. According to the severity of the CT changes, 86 of the 91 patients were classed into five stages from A1 to A5. Morphological stages (A1-A5) were well correlated to the functional disability stages by Ueda with a correlation factor of r=0.88. (J.P.N.)

  6. Radiological protection in paediatric computed tomography

    International Nuclear Information System (INIS)

    Khong, P-L.; Frush, D.; Ringertz, H.

    2012-01-01

    It is well known that paediatric patients are generally at greater risk for the development of cancer per unit of radiation dose compared with adults, due both to the longer life expectancy for any harmful effects of radiation to manifest, and the fact that developing organs and tissues are more sensitive to the effects of radiation. Multiple computed tomography (CT) examinations may cumulatively involve absorbed doses to organs and tissues that can sometimes approach or exceed the levels known from epidemiological studies to significantly increase the probability of cancer development. Radiation protection strategies include rigorous justification of CT examinations and the use of imaging techniques that are non-ionising, followed by optimisation of radiation dose exposure (according to the ‘as low as reasonably achievable’ principle). Special consideration should be given to the availability of dose reduction technology when acquiring CT scanners. Dose reduction should be optimised by adjustment of scan parameters (such as mAs, kVp, and pitch) according to patient weight or age, region scanned, and study indication (e.g. images with greater noise should be accepted if they are of sufficient diagnostic quality). Other strategies include restricting multiphase examination protocols, avoiding overlapping of scan regions, and only scanning the area in question. Newer technologies such as tube current modulation, organ-based dose modulation, and iterative reconstruction should be used when appropriate. Attention should also be paid to optimising study quality (e.g. by image post-processing to facilitate radiological diagnoses and interpretation). Finally, improving awareness through education and advocacy, and further research in paediatric radiological protection are important to help reduce patient dose.

  7. X-ray Computed Tomography Image Quality Indicator (IQI) Development

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase one of the program is to identify suitable x-ray Computed Tomography (CT) Image Quality Indicator (IQI) design(s) that can be used to adequately capture CT...

  8. Perfusion computed tomography to assist decision making for stroke thrombolysis.

    Science.gov (United States)

    Bivard, Andrew; Levi, Christopher; Krishnamurthy, Venkatesh; McElduff, Patrick; Miteff, Ferdi; Spratt, Neil J; Bateman, Grant; Donnan, Geoffrey; Davis, Stephen; Parsons, Mark

    2015-07-01

    The use of perfusion imaging to guide selection of patients for stroke thrombolysis remains controversial because of lack of supportive phase three clinical trial evidence. We aimed to measure the outcomes for patients treated with intravenous recombinant tissue plasminogen activator (rtPA) at a comprehensive stroke care facility where perfusion computed tomography was routinely used for thrombolysis eligibility decision assistance. Our overall hypothesis was that patients with 'target' mismatch on perfusion computed tomography would have improved outcomes with rtPA. This was a prospective cohort study of consecutive ischaemic stroke patients who fulfilled standard clinical/non-contrast computed tomography eligibility criteria for treatment with intravenous rtPA, but for whom perfusion computed tomography was used to guide the final treatment decision. The 'real-time' perfusion computed tomography assessments were qualitative; a large perfusion computed tomography ischaemic core, or lack of significant perfusion lesion-core mismatch were considered relative exclusion criteria for thrombolysis. Specific volumetric perfusion computed tomography criteria were not used for the treatment decision. The primary analysis compared 3-month modified Rankin Scale in treated versus untreated patients after 'off-line' (post-treatment) quantitative volumetric perfusion computed tomography eligibility assessment based on presence or absence of 'target' perfusion lesion-core mismatch (mismatch ratio >1.8 and volume >15 ml, core computed tomography-selected rtPA-treated patients to an Australian historical cohort of non-contrast computed tomography-selected rtPA-treated patients. Of 635 patients with acute ischaemic stroke eligible for rtPA by standard criteria, thrombolysis was given to 366 patients, with 269 excluded based on visual real-time perfusion computed tomography assessment. After off-line quantitative perfusion computed tomography classification: 253 treated patients and

  9. Computed tomography of the head in neurological examination of children

    International Nuclear Information System (INIS)

    Baeckman, E.; Egg-Olofsson, O.; Raadberg, C.

    1980-01-01

    A total of 247 children from the departments of pediatrics and neurosurgery were examined with computed tomography of the head during a two year period in 1977-78. Pathological changes were demonstrated in 79 per cent. Supplementary neuro-radiological examination - angiography and encephalography - was necessary in 17 per cent. Computed tomography together with the clinical assessment frequently suffices for final diagnosis. Computed tomography greatly reduces the need for previously used neurological examinations including skull radiography. Complications may ensure because of over-sensitivity to intravenously administered contrast medium in connection with anesthesia, and the radiation dose particularly to the crystalline lens of the eye must be taken into account. Computed tomography should therefore be used only on strict indications after careful scrutiny of the case history and the status. (author)

  10. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to demonstrate key elements of feasibility for a high speed automated time domain terahertz computed axial tomography (TD-THz CT) non destructive...

  11. Estimation of feline renal volume using computed tomography and ultrasound.

    Science.gov (United States)

    Tyson, Reid; Logsdon, Stacy A; Werre, Stephen R; Daniel, Gregory B

    2013-01-01

    Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes' principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand-traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (-10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies. © 2012 Veterinary Radiology & Ultrasound.

  12. Detection of Foreign Bodies by Spiral Computed Tomography and Cone Beam Computed Tomography in Maxillofacial Regions

    Directory of Open Access Journals (Sweden)

    Farzaneh Kaviani

    2014-09-01

    Full Text Available Background and aims. The imaging techniques commonly used for foreign body detection include plain radiography, xeroradiography, computed tomography (CT scans, magnetic resonance imaging (MRI and ultrasonography. The aim of the present study was to compare cone-beam computed tomography (CBCT with conventional CT scan in determination of the exact location of a foreign body in the maxillofacial area in vitro. Materials and methods. In this descriptive study, seven different materials were selected as foreign bodies with dimen-sions of approximately 2 mm, 1 mm, and 0.5 mm. These materials consisted of metal, glass, wood, stone, plastic, graphite and tooth. These foreign bodies were placed in a sheep head between the corpus of the mandible and muscle, in the tongue and in an air space. One conventional CT scan and two CBCT scans were made on the models. Results. Tooth, metal, stone and glass foreign bodies were seen clearly on CT and CBCT scans made by NewTom at the smallest size in air. However, CBCT scan by NewTom was a more effective technique for visualization of foreign bodies in air compared to conventional CT. Foreign bodies measuring 0.5 mm made of metal, stone, glass, graphite and teeth were detected by all devices in muscle tissue and adjacent bone. Conclusion. According to the results, CBCT scans of NewTom and Planmeca are appropriate tools for detecting foreign bodies with relative high density in the maxillofacial area.

  13. Comparative dosimetry of dental cone beam computed tomography, panoramic radiography, and multislice computed tomography

    International Nuclear Information System (INIS)

    Sezgin, O.S.; Kayipmaz, S.; Yasar, D.; Yilmaz, A.B.; Ozturk, M.H.

    2012-01-01

    The aim of this study was to compare the effective organ doses from cone beam computed tomography (CBCT), multislice computed tomography (MSCT), and panoramic radiography. The tissue-absorbed doses for the Kodak 9500 CBCT system, NewTom FP CBCT system, Morita Veraviewepocs panoramic X-ray device, and Somatom Sensation 16 MSCT system were calculated using thermoluminescent dosimeter chips placed at selected locations on a radiation analog dosimetry phantom. The tissue weighting factors recommended by the International Commission on Radiological Protection in 2007 were used to obtain effective doses. The effective doses from the CBCT systems were 118.65, 84.45, and 75.43 μSv for the Kodak 9500 large field of view (FOV), NewTom FP, and Kodak 9500 medium FOV, respectively. The effective doses were 11.37 μSv for the panoramic X-ray examination, 583.73 μSv for the MSCT ''Dental'' protocol, and 1983.89 μSv for the MSCT ''NeckThinSlice'' protocol. The doses from CBCT are not sufficiently low to allow its use as a routine imaging technique instead of panoramic radiography. The FOV size should be chosen carefully to prevent excessive exposure of the patient to radiation. The use of MSCT in dentistry is associated with much radiation and should be avoided in cases where CBCT is adequate for 3D evaluation. (author)

  14. GPU computing and applications

    CERN Document Server

    See, Simon

    2015-01-01

    This book presents a collection of state of the art research on GPU Computing and Application. The major part of this book is selected from the work presented at the 2013 Symposium on GPU Computing and Applications held in Nanyang Technological University, Singapore (Oct 9, 2013). Three major domains of GPU application are covered in the book including (1) Engineering design and simulation; (2) Biomedical Sciences; and (3) Interactive & Digital Media. The book also addresses the fundamental issues in GPU computing with a focus on big data processing. Researchers and developers in GPU Computing and Applications will benefit from this book. Training professionals and educators can also benefit from this book to learn the possible application of GPU technology in various areas.

  15. Pulmonary artery aneurysm in Bechcet's disease: helical computed tomography study

    International Nuclear Information System (INIS)

    Munoz, J.; Caballero, P.; Olivera, M. J.; Cajal, M. L.; Caniego, J. L.

    2000-01-01

    Behcet's disease is a vasculitis of unknown etiology that affects arteries and veins of different sizes and can be associated with pulmonary artery aneurysms. We report the case of a patient with Behcet's disease and a pulmonary artery aneurysm who was studied by means of plain chest X ray, helical computed tomography and pulmonary arteriography. Helical computed tomography is a reliable technique for the diagnosis and follow-up of these patients. (Author) 9 refs

  16. Pleuropancreatic fistula: endoscopic retrograde cholangiopancreatography and computed tomography

    International Nuclear Information System (INIS)

    McCarthy, S.; Pellegrini, C.A.; Moss, A.A.; Way, L.W.

    1984-01-01

    The complementary use of endoscopic retrograde cholangiopancreatography and computed tomography in the diagnosis and management of pleuropancreatic fistulas is described in relation to four cases in which computed tomography revealedthe thoracic extension of a pancreatic fistula not demonstrable by endoscopic retrograde cholangiopancreatography, although the latter indicated an abnormal pancreatic duct. The complementary use of both techniques may be necessary to define the pathologic anatomy so that the appropriate therapy, particularly the surgical approach, can be decided

  17. Computed Tomography - "The Changing Role of Maxillofacial Imaging"

    Directory of Open Access Journals (Sweden)

    Ambika Gupta

    2005-01-01

    Full Text Available The past three decades have witnessed great advances in the field of diagnostic imaging. Many of these advances have greatly facilitated the diagnosis and treatment of a number of maxillofacial disorders. These modalities while employing different physical principles, are often complimentary, providing valuable information about different aspects of a given disease process. Computed Tomography, 3-D Computed Tomography, and Magnetic Resonance Imaging are some such valuable adjuncts, which have opened new dimensions in the diagnosis of maxillofacial disorders.

  18. Myocardial perfusion with multi-detector computed tomography: quantitative evaluation

    International Nuclear Information System (INIS)

    Carrascosa, Patricia M.; Vallejos, J.; Capunay, Carlos M.; Deviggiano, A.; Carrascosa, Jorge M.

    2007-01-01

    The objective of this work is to evaluate the skill of multidetector computer tomography, to quantify the different patterns of intensification during the evaluation of the myocardial perfusion. 45 patients were studied with suspicion of cardiovascular disease. Multi-detector computed tomography was utilized on patients at rest and in effort with pharmacological stress, after the administration of dipyridamole. Also they were evaluated using nuclear medicine [es

  19. Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies

    International Nuclear Information System (INIS)

    Boujelbene, N.; Mirimanoff, R.O.; Ozsahin, M.; Zouhair, A.; Prior, J.O.; Boubaker, A.; Azria, D.; Schaffer, M.; Gez, E.; Jichlinski, P.; Meuwly, J.Y.

    2011-01-01

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. (authors)

  20. Analysis of the computed tomography in the acute abdomen; Analise da tomografia computadorizada no abdome agudo

    Energy Technology Data Exchange (ETDEWEB)

    Hochhegger, Bruno [Complexo Hospitalar Santa Casa de Porto Alegre, RS (Brazil); Moraes, Everton [Universidade Federal de Santa Maria (UFSM), RS (Brazil); Haygert, Carlos Jesus Pereira; Antunes, Paulo Sergio Pase [Hospital Universitario de Santa Maria, RS (Brazil); Gazzoni, Fernando [Pontificia Universidade Catolica de Porto Alegre (PUC-RS), Porto Alegre, RS (Brazil). Hospital Sao Lucas; Andrade, Rubens Gabriel Feijo [Fundacao Universitaria de Cardiologia de Porto Alegre, RS (Brazil). Inst. de Cardiologia; Bueno, Leticia Rossi [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Lopes, Luis Felipe Dias [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Estatistica]. E-mail: brunorgs@pop.com.br

    2007-07-01

    Introduction: This study tends to test the capacity of the computed tomography in assist in the diagnosis and the approach of the acute abdomen. Material and method: This is a longitudinal and prospective study, in which were analyzed the patients with the diagnosis of acute abdomen. There were obtained 105 cases of acute abdomen and after the application of the exclusions criteria were included 28 patients in the study. Results: Computed tomography changed the diagnostic hypothesis of the physicians in 50% of the cases (p < 0.05), and the confidence index in 85.71% of the cases (p 0.014). Computed tomography also altered the management in 46.43% of the cases (p > 0.05), where 78.57% of the patients had surgical indication before computed tomography and 67.86% after computed tomography (p = 0.0546). The index of accurate diagnosis of computed tomography, when compared to the anatomopathologic examination and the final diagnosis, was observed in 82.14% of the cases (p = 0.013). When the analysis was done dividing the patients in surgical and nonsurgical group, were obtained an accuracy of 89.28% (p 0.0001). The difference of 7.2 days of hospitalization (p = 0.003) was obtained compared with the mean of the acute abdomen without use the computed tomography. Conclusion: The computed tomography is correlative with the anatomopathology and has great accuracy in the surgical indication, associated with the capacity of increase the confident index of the physicians, reduces the hospitalization time, reduces the number of surgeries and is cost-effective. (author)

  1. Whole body positron emission tomography/computed tomography staging of metastatic choroidal melanoma.

    Science.gov (United States)

    Kurli, Madhavi; Reddy, Shantan; Tena, Lawrence B; Pavlick, Anna C; Finger, Paul T

    2005-08-01

    To evaluate whole-body positron emission tomography (PET)/computed tomography in staging of patients with metastatic choroidal melanoma. Interventional non-randomized clinical study. Twenty patients were referred for whole-body 18-fluoro-2-deoxy-D-glucose (FDG) PET/computed tomography imaging because of suspected metastatic choroidal melanoma. PET/computed tomography images were studied for the presence and distribution of metastatic melanoma. Subsequent biopsies were performed to confirm the presence of metastatic disease. Twenty patients underwent PET/computed tomography. Eighteen were imaged because of abnormal clinical, hematologic, or radiographic screening studies during the course of their follow-up after plaque brachytherapy or enucleation. Two were imaged before treatment of their primary tumor. PET/computed tomography revealed or confirmed metastatic melanoma in eight (40%) of these 20 patients. The mean time from initial diagnosis to metastasis was 47 months (range 0 to 154). The most common sites for metastases were the liver (100%), bone (50%), lung (25%), lymph nodes (25%), and subcutaneous tissue (25%). Cardiac, brain, thyroid, and posterior abdominal wall lesions (12.5%) were also noted. Six patients (75%) had multiple organ involvement. No false positives were noted. PET/computed tomography imaging also detected benign lesions of the bone and lymph nodes in three patients (15%). All patients had hepatic metastases and liver enzyme assays were abnormal in only one (12.5%) of eight patients. PET/computed tomography imaging is a sensitive tool for the detection and localization of hepatic and extra-hepatic (particularly osseous) metastatic choroidal melanoma.

  2. Detection of root perforations using conventional and digital intraoral radiography, multidetector computed tomography and cone beam computed tomography

    OpenAIRE

    Shokri, Abbas; Eskandarloo, Amir; Noruzi-Gangachin, Maruf; Khajeh, Samira

    2014-01-01

    Objectives This study aimed to compare the accuracy of conventional intraoral (CI) radiography, photostimulable phosphor (PSP) radiography, cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) for detection of strip and root perforations in endodontically treated teeth. Materials and Methods Mesial and distal roots of 72 recently extracted molar were endodontically prepared. Perforations were created in 0.2, 0.3, or 0.4 mm diameter around the furcation o...

  3. Computed tomography of the orbital tumors

    International Nuclear Information System (INIS)

    Choi, Jai Korl; Lee, Hwang Bok; Kang, Eun Young; Seol, Hae Young; Suh, Won Hyuck; Ahn, Byeong Yeob

    1987-01-01

    The development of computed tomography (CT) provided a noninvasive safe technique for imaging the orbit in any plane exquisitely demonstrating its normal anatomy as well as its pathologic process. The orbit is an ideal structure to be examined by CT because of large difference of absorption values between the intraorbital fat, muscle, optic nerve and vessels. In this study, the authors reviewed CT findings of 66 pathologically proven orbital tumors and tumorous conditions among the total of 98 cases who had taken orbital CT scan because if exophthalmos, ocular pain, diplopia and other ophthalmologic symptoms suggesting orbital masses during the period of 3 years. For the analysis of characteristic CT findings of the orbital lesions, all lesions are divided into 4 groups according to the site of origin, i.e., tumors arising in the eyeball (group 1); from intraconal space (group 2); from extraconal space (group 3); and from extraorbital regions (group 4). The results are as follows; 1.Extra tumor detection and localization was possible in 63 cases. Thus the detection rate was 95% with CT scan. 2.Among 36 males and 30 females, their age ranged from 10 months to 72 years. 3.Intraocular tumors (group 1) were 10 cases. Retinoblastoma occurred wholly in the young children under 5 years and combined with calcification in 57%. Choroidal melanoma occurred wholly in adults. 4.Intraconal tumors (group 2) were 9 cases. Vascular tumors (7 cases) were the most frequent and well enhancing mass. 5.The tumors arising in the extraconal region (group 3) were pseudotumor (12 cases), lymphoma (3 cases), dermoid cyst (4 cases), metastasis (2 cases), adenoid cystic carcinoma (1 case) and teratoma (1 case). A case of lymphoma demonstrating retrobulbar ill defined mass with scleral l thickening could not be differentiated from the pseudotumor which showing similar finding. 6.The lesions arising from extraorbital region (group 4) were PNS cancer (9 cases), mucocele (3 cases), lid cancer (4

  4. An industrial demonstration of computer assisted tomography

    International Nuclear Information System (INIS)

    Lupton, L.R.

    1985-09-01

    Computerized tomography (CT) is a nondestructive testing technique for generating quantitative density (linear attenuation coefficient) maps of a cross section through an object. By using a series of parallel tomographic images taken at different elevations, a three-dimensional (3-D) map of the object can be obtained. To demonstrate the power of tomography, a 3-D region of a motorcycle carburetor has been imaged using twenty-four parallel two-dimensional images. From these data, new images in planes orthogonal to the original planes have been generated, thereby improving the user's ability to visualize the position of components within the carburetor. The data have also been used to demonstrate the relationship between tomography and radiography

  5. Comparison of computed tomography with radionuclide tomography in chest diagnosis

    International Nuclear Information System (INIS)

    Takayama, Makoto; Katsuyama, Naofumi; Kawakami, Kenji; Tada, Shimpei

    1979-01-01

    Abnormal accumulation of 67 Ga citrate detected by RI tomoscan, PHO/CON, was compared with the findings of CT image by ACTA 0100 in intrathoracic diseases. Diagnostic efficacy of the RI tomoscan and CT on anatomical localization of the lesion detected by both methods were discussed. Comparative study was performed in 30 cases with malignant tumor of the lung and the mediastinum; 12 cases of primary lung cancer, 6 cases of metastatic lung cancer, 2 cases of malignant lymphoma and 10 others. Eighteen of the 30 cases showed definite evidence of enlarged mediastinal lymph nodes and/or hilar lymph nodes either by chest plain film, chest tomography or CT. Localization of 67 Ga deposit was divided into 3 groups; 1) mediastinal region, 2) hilar region and 3) lung field. The localization of lesions in each group was compared with the findings of CT image. The findings by both methods were well correlated in all cases but one. The RI tomoscan, PHO/CON, can facilitate the localization of 67 Ga accumulation by tomographic manner, and it appears to be possible to identify anatomically subdivided mediastinal lymph node groups by the combined study of RI tomoscan and CT. (author)

  6. Clinical application of scalp markers and three-dimensional sliced computer tomography reconstructions of the skull transverse-sigmoid sinus groove in the retrosigmoid approach.

    Science.gov (United States)

    Wang, Chao; Guoqiang, Han; You, Chao; Liu, Chuangxi

    2017-01-17

    To explore the clinical value of bone flap creation and the sinus protection in the approach of retrosigmoid keyhole craniotomy with the guidance of three-dimensional (3D) sliced computer tomography (CT) reconstruction of the skull transverse sinus and sigmoid sinus groove. The scalp tracings of the transverse sinus and sigmoid sinus groove of 108 posterior fossa lesion patients were delineated by gentian violet, which relies on the relationship between its 3D reconstruction location and scalp marker. The craniotomy was executed with the guidance of its surface tracings. The intraoperative findings of exposure and damage of transverse sinus, sigmoid sinus, morphology, stability, complications, and postoperative appearance of bone flap restoration were evaluated. Morphological analysis of the transverse-sigmoid sinus groove showed right superiority, left superiority, and balanced type in 61, 18, and 29 cases, respectively, and the relationship between the asterion and the transverse-sigmoid sinus groove showed that asterion sites were located in the upper portion, onto, and below the transverse and sigmoid sinus groove in 19, 68, and 21 cases, respectively. Good intraoperative exposure without damage of transverse sinus and sigmoid sinus, good stability and appearance of bone flap restoration, and no postoperative pseudomeningocele were obtained after using this method to locate the transverse sinus and sigmoid sinus. The 3D sliced CT reconstruction of the skull transverse sinus and sigmoid sinus groove was helpful in the approach of retrosigmoid craniotomy for sinus exposure, sinus protection, and the prevention of cerebrospinal fluid leakage and pseudomeningocele.

  7. Coronary Computed Tomography Angiography Derived Fractional Flow Reserve and Plaque Stress

    DEFF Research Database (Denmark)

    Nørgaard, Bjarne Linde; Leipsic, Jonathon; Koo, Bon-Kwon

    2016-01-01

    Fractional flow reserve (FFR) measured during invasive coronary angiography is an independent prognosticator in patients with coronary artery disease and the gold standard for decision making in coronary revascularization. The integration of computational fluid dynamics and quantitative anatomic...... and physiologic modeling now enables simulation of patient-specific hemodynamic parameters including blood velocity, pressure, pressure gradients, and FFR from standard acquired coronary computed tomography (CT) datasets. In this review article, we describe the potential impact on clinical practice...... and the science behind noninvasive coronary computed tomography (CT) angiography derived fractional flow reserve (FFRCT) as well as future applications of this technology in treatment planning and quantifying forces on atherosclerotic plaques....

  8. Administration of biliary contrast media in computed tomography

    International Nuclear Information System (INIS)

    Huebener, K.-H.; Treugut, H.

    1981-01-01

    Biliary contrast media have 2 main uses in computed tomography (CT) of the liver and bile ducts: 1. Labelling of extrahepatic bile ducts in order to aid in the identification of the common bile ducts and the papilla of Vater, particularly in cases of complex, mostly postoperative situs. 2. Differentiation between normal and abnormal liver tissue in cases of focal nodular hyperplasia with proliferation of tumorous bile ducts. The applicability of biliary contrast media is rather limited as far as the improvement of spatial resolution by an increase of contrast is concerned, because the attainable enhancement today remains small. The possibility of interpretation of the liver function is likewise insufficient, because the standard deviation of the time-dependent enhancement is too great in the normal collective in order to register deviations reliably. In cases of liver cirrhosis, a rise of density of at least 40-60 Hounsfield Units (HU) would be desirable. (Auth.)

  9. Brain perfusion: computed tomography and magnetic resonance techniques.

    Science.gov (United States)

    Copen, William A; Lev, Michael H; Rapalino, Otto

    2016-01-01

    Cerebral perfusion imaging provides assessment of regional microvascular hemodynamics in the living brain, enabling in vivo measurement of a variety of different hemodynamic parameters. Perfusion imaging techniques that are used in the clinical setting usually rely upon X-ray computed tomography (CT) or magnetic resonance imaging (MRI). This chapter reviews CT- and MRI-based perfusion imaging techniques, with attention to image acquisition, clinically relevant aspects of image postprocessing, and fundamental differences between CT- and MRI-based techniques. Correlations with cerebrovascular physiology and potential clinical applications of perfusion imaging are reviewed, focusing upon the two major classes of neurologic disease in which perfusion imaging is most often performed: primary perfusion disorders (including ischemic stroke, transient ischemic attack, and reperfusion syndrome), and brain tumors. © 2016 Elsevier B.V. All rights reserved.

  10. Three-dimensional computed tomography of the acetabulum

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi Mucelli, R.S.; Muner, G.; Pozzi Mucelli, F.; Pozzi Mucelli, M.; Marotti, F.; Dalla Palma, L.

    1986-08-01

    Acetabular fractures represent a complex variety that are classified in different types. Conventional radiology is often inadequate to demonstrate and classify the fractures. Computed tomography (CT) has already been shown to be superior in this field. A further advantage of CT is represented by the recent availability of three-dimensional (3D) images that are realized from axial CT scans by means of a new software. The Authors report the applications of this new software to the study of the normal acetabulum and in patients with fractures. 3D images allows an effective demonstration of the fracture, its irradiation and the dislocation of bone fragments. The information is contained in one or few images rather than many axial images. Therefore the role of 3D images may be considered complementary to axial CT scans.

  11. Segmentation of pulmonary nodules in computed tomography using a regression neural network approach and its application to the Lung Image Database Consortium and Image Database Resource Initiative dataset.

    Science.gov (United States)

    Messay, Temesguen; Hardie, Russell C; Tuinstra, Timothy R

    2015-05-01

    We present new pulmonary nodule segmentation algorithms for computed tomography (CT). These include a fully-automated (FA) system, a semi-automated (SA) system, and a hybrid system. Like most traditional systems, the new FA system requires only a single user-supplied cue point. On the other hand, the SA system represents a new algorithm class requiring 8 user-supplied control points. This does increase the burden on the user, but we show that the resulting system is highly robust and can handle a variety of challenging cases. The proposed hybrid system starts with the FA system. If improved segmentation results are needed, the SA system is then deployed. The FA segmentation engine has 2 free parameters, and the SA system has 3. These parameters are adaptively determined for each nodule in a search process guided by a regression neural network (RNN). The RNN uses a number of features computed for each candidate segmentation. We train and test our systems using the new Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) data. To the best of our knowledge, this is one of the first nodule-specific performance benchmarks using the new LIDC-IDRI dataset. We also compare the performance of the proposed methods with several previously reported results on the same data used by those other methods. Our results suggest that the proposed FA system improves upon the state-of-the-art, and the SA system offers a considerable boost over the FA system. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Spectrum of single photon emission computed tomography/computed tomography findings in patients with parathyroid adenomas.

    Science.gov (United States)

    Chakraborty, Dhritiman; Mittal, Bhagwant Rai; Harisankar, Chidambaram Natrajan Balasubramanian; Bhattacharya, Anish; Bhadada, Sanjay

    2011-01-01

    Primary hyperparathyroidism results from excessive parathyroid hormone secretion. Approximately 85% of all cases of primary hyperparathyroidism are caused by a single parathyroid adenoma; 10-15% of the cases are caused by parathyroid hyperplasia. Parathyroid carcinoma accounts for approximately 3-4% of cases of primary disease. Technetium-99m-sestamibi (MIBI), the current scintigraphic procedure of choice for preoperative parathyroid localization, can be performed in various ways. The "single-isotope, double-phase technique" is based on the fact that MIBI washes out more rapidly from the thyroid than from abnormal parathyroid tissue. However, not all parathyroid lesions retain MIBI and not all thyroid tissue washes out quickly, and subtraction imaging is helpful. Single photon emission computed tomography (SPECT) provides information for localizing parathyroid lesions, differentiating thyroid from parathyroid lesions, and detecting and localizing ectopic parathyroid lesions. Addition of CT with SPECT improves the sensitivity. This pictorial assay demonstrates various SPECT/CT patterns observed in parathyroid scintigraphy.

  13. Applications of Evolutionary Computation

    NARCIS (Netherlands)

    Mora, Antonio M.; Squillero, Giovanni; Di Chio, C; Agapitos, Alexandros; Cagnoni, Stefano; Cotta, Carlos; Fernández De Vega, F; Di Caro, G A; Drechsler, R.; Ekárt, A; Esparcia-Alcázar, Anna I.; Farooq, M; Langdon, W B; Merelo-Guervós, J.J.; Preuss, M; Richter, O.-M.H.; Silva, Sara; Sim$\\$~oes, A; Squillero, Giovanni; Tarantino, Ernesto; Tettamanzi, Andrea G B; Togelius, J; Urquhart, Neil; Uyar, A S; Yannakakis, G N; Smith, Stephen L; Caserta, Marco; Ramirez, Adriana; Voß, Stefan; Squillero, Giovanni; Burelli, Paolo; Mora, Antonio M.; Squillero, Giovanni; Jan, Mathieu; Matthias, M; Di Chio, C; Agapitos, Alexandros; Cagnoni, Stefano; Cotta, Carlos; Fernández De Vega, F; Di Caro, G A; Drechsler, R.; Ekárt, A; Esparcia-Alcázar, Anna I.; Farooq, M; Langdon, W B; Merelo-Guervós, J.J.; Preuss, M; Richter, O.-M.H.; Silva, Sara; Sim$\\$~oes, A; Squillero, Giovanni; Tarantino, Ernesto; Tettamanzi, Andrea G B; Togelius, J; Urquhart, Neil; Uyar, A S; Yannakakis, G N; Caserta, Marco; Ramirez, Adriana; Voß, Stefan; Squillero, Giovanni; Burelli, Paolo; Esparcia-Alcazar, Anna I; Silva, Sara; Agapitos, Alexandros; Cotta, Carlos; De Falco, Ivanoe; Cioppa, Antonio Della; Diwold, Konrad; Ekart, Aniko; Tarantino, Ernesto; Vega, Francisco Fernandez De; Burelli, Paolo; Sim, Kevin; Cagnoni, Stefano; Simoes, Anabela; Merelo, J.J.; Urquhart, Neil; Haasdijk, Evert; Zhang, Mengjie; Squillero, Giovanni; Eiben, A E; Tettamanzi, Andrea G B; Glette, Kyrre; Rohlfshagen, Philipp; Schaefer, Robert; Caserta, Marco; Ramirez, Adriana; Voß, Stefan

    2015-01-01

    The application of genetic and evolutionary computation to problems in medicine has increased rapidly over the past five years, but there are specific issues and challenges that distinguish it from other real-world applications. Obtaining reliable and coherent patient data, establishing the clinical

  14. Artifacts in orthodontic bracket systems in cone-beam computed tomography and multislice computed tomography.

    Science.gov (United States)

    Hirschinger, V; Hanke, S; Hirschfelder, U; Hofmann, E

    2015-03-01

    The purpose of this study was to quantify artifacts caused by different bracket systems in cone-beam computed tomography (CBCT) and multislice computed tomography (MSCT) scans. Orthodontic brackets of four different systems were consecutively bonded to the surface of a residual molar on a human cadaveric mandible. One MSCT system and three CBCT units were used to scan each of the four bonded brackets, in addition to obtaining a blank reference scan of the tooth surface. All datasets were registered to the reference dataset using visualization software (Analyze 11.0® by AnalyzeDirect). Artifact-related reductions in image quality were expressed in percent of theoretical maximum standard deviations (SD) obtained for the gray values of the adjacent voxels, with higher percentages correlating more pronounced artifacts. Both the SD percentages for three defined line profiles and their mean values were almost invariably higher with the MSCT system than with the CBCT units. Looking into the individual SD percentages, two of the CBCT units (Pax Zenith 3D® and Picasso Trio®; both Vatech) produced higher values than the MSCT system (SOMATOM Definition AS+®; Siemens) in some line profiles. The titanium bracket, in particular, was associated with marked differences between the two scanner technologies, as the mean artifact intensities from this bracket were particularly high with the MSCT unit and relatively low with the CBCT units. The artifact intensities observed with the other three bracket systems varied widely depending on which scanner was used. Different artifact intensities were noted depending on the composition of the bracket system and on the scanner technology (MSCT/CBCT). While the artifacts manifested themselves differently with different scanners, their adverse effects were comparable. However, given the variable severity of the artifacts observed depending on the materials scanned and the scanners used, a blanket recommendation for or against MSCT or CBCT

  15. Computed tomography (CT) of orbital cellulitis

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, H.; Hara, K.; Okamura, R.; Watanabe, T.; Nagata, M. (Kumamoto Univ. (Japan). School of Medicine)

    1981-12-01

    Two cases of orbital cellulitis showed a tumor-like shadow in the orbit on CT examination. Abnormal shadows were also noticed in both cases in the frontal and ethmoid sinuses. Postoperatively, one case was diagnosed as pyocele of the frontal sinus, the other as sinusitis with subperitoneal hematoma. In these diagnoses, plane skull X-P, tomography and CT scanning were valuable.

  16. Whole-body magnetic resonance imaging and positron emission tomography-computed tomography in oncology.

    Science.gov (United States)

    Schmidt, Gerwin P; Kramer, Harald; Reiser, Maximilian F; Glaser, Christian

    2007-06-01

    The advent of positron emission tomography-computed tomography (PET-CT) and whole-body magnetic resonance imaging (WB-MRI) has introduced tumor imaging with a systemic and functional approach compared with established sequential, multimodal diagnostic algorithms.Whole-body PET with [18F]-fluoro-2-desoxy-glucose is a useful imaging procedure for tumor staging and monitoring that can visualize active tumor tissue by detecting pathological glucose metabolism. The combination of PET with the detailed anatomical information of multislice computed tomography as dual-modality scanners has markedly increased lesion localization and diagnostic accuracy compared with both modalities as standalone applications.Hardware innovations, such as the introduction of multi-receiver channel whole-body MRI scanners at 1.5 and, recently, 3 T, combined with acquisition acceleration techniques, have made high-resolution WB-MRI clinically feasible. Now, a dedicated assessment of individual organs with various soft tissue contrast, spatial resolution, and contrast media dynamics can be combined with whole-body anatomical coverage in a multiplanar imaging approach. More flexible protocols (eg, T1-weighted turbo spin-echo and short inversion recovery imaging, dedicated lung imaging or dynamic contrast-enhanced studies of the abdomen) can be performed within 45 minutes.Whole-body magnetic resonance imaging has recently been proposed for tumor screening of asymptomatic individuals, and potentially life-changing diagnoses, such as formerly unknown malignancy, have been reported. However, larger patient cohort studies will have to show the cost efficiency and the clinical effectiveness of such an approach.For initial tumor staging, PET-CT has proved more accurate for the definition of T-stage and lymph node assessment, mainly because of the missing metabolic information in WB-MRI. However, new applications, such as magnetic resonance whole-body diffusion-weighted imaging or lymphotropic contrast

  17. Quantifying the debonding of inclusions through tomography and computational homology.

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei-Yang; Johnson, George C. (University of California, Berkeley, Berkeley, CA); Mota, Alejandro; Foulk, James W., III; Jin, Huiqing

    2010-09-01

    This report describes a Laboratory Directed Research and Development (LDRD) project to use of synchrotron-radiation computed tomography (SRCT) data to determine the conditions and mechanisms that lead to void nucleation in rolled alloys. The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) has provided SRCT data of a few specimens of 7075-T7351 aluminum plate (widely used for aerospace applications) stretched to failure, loaded in directions perpendicular and parallel to the rolling direction. The resolution of SRCT data is 900nm, which allows elucidation of the mechanisms governing void growth and coalescence. This resolution is not fine enough, however, for nucleation. We propose the use statistics and image processing techniques to obtain sub-resolution scale information from these data, and thus determine where in the specimen and when during the loading program nucleation occurs and the mechanisms that lead to it. Quantitative analysis of the tomography data, however, leads to the conclusion that the reconstruction process compromises the information obtained from the scans. Alternate, more powerful reconstruction algorithms are needed to address this problem, but those fall beyond the scope of this project.

  18. Development of a proton Computed Tomography Detector System

    Energy Technology Data Exchange (ETDEWEB)

    Naimuddin, Md. [Delhi U.; Coutrakon, G. [Northern Illinois U.; Blazey, G. [Northern Illinois U.; Boi, S. [Northern Illinois U.; Dyshkant, A. [Northern Illinois U.; Erdelyi, B. [Northern Illinois U.; Hedin, D. [Northern Illinois U.; Johnson, E. [Northern Illinois U.; Krider, J. [Northern Illinois U.; Rukalin, V. [Northern Illinois U.; Uzunyan, S. A. [Northern Illinois U.; Zutshi, V. [Northern Illinois U.; Fordt, R. [Fermilab; Sellberg, G. [Fermilab; Rauch, J. E. [Fermilab; Roman, M. [Fermilab; Rubinov, P. [Fermilab; Wilson, P. [Fermilab

    2016-02-04

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantegeous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

  19. Dose estimation for paediatric cranial computed tomography

    International Nuclear Information System (INIS)

    Curci Daros, K.A.; Bitelli Medeiros, R.; Curci Daros, K.A.; Oliveira Echeimberg, J. de

    2006-01-01

    In the last ten years, the number of paediatric computed tomography (CT) scans have increased worldwide, contributing to higher population radiation dose. Technique diversification in paediatrics and different CT equipment technologies have led to various exposure levels complicating precise evaluation of doses and operational conditions necessary for good quality images. The objective of this study was to establish a quantitative relationship between absorbed dose and cranial region in children up to 6 years old undergoing CT exams. Methods: X-ray was measured on the cranial surface of 64 patients undergoing CT using thermoluminescent (T.L.) dosimeters. Forty T.L.D.100 thermoluminescent dosimeters (T.L.D.) were evenly distributed on each patients skin surface along the sagittal axis. Measurements were performed in facial regions exposed to scatter radiation and in the supratentorial and posterior fossa regions, submitted to primary radiation. T.L.D. were calibrated for 120 kV X-ray over the acrylic phantom. T.L. measurements were made with a Harshaw 4000 system. Patient mean T.L. readings were determined for position, pi, of T.L.D. and normalized to the maximum supratentorial reading. From integrating the linear T.L. density function (?) resulting from radiation distribution in each of the three exposed regions, dose fraction was determined in the region of interest, along with total dose under the technical conditions used in that specific exam protocol. For each T.L.D. position along the patient cranium, there were n T.L. measurements with 2% uncertainty due to T.L. reader, and 5% due to thermal treatment of dosimeters. Also, mean T.L. readings and their uncertainties were calculated for each patient at each position, p. Results: Mean linear T.L. density for the region exposed to secondary radiation defined by position, 0.3≤p≤6 cm, was ρ((p)=7.9(4)x10 -2 +7(5)x10 -5 p 4.5(4) cm -1 ; exposed to primary X-ray for the posterior fossa region defined by position

  20. Evaluating iterative reconstruction performance in computed tomography.

    Science.gov (United States)

    Chen, Baiyu; Ramirez Giraldo, Juan Carlos; Solomon, Justin; Samei, Ehsan

    2014-12-01

    Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d'). d' was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1-4 mm), contrast levels (10-100 HU), and edge profiles (sharp and soft). Unique d' values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDIvol: 3.4-64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d' values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction potentials (11-54 mGy, 77%-84%), followed by

  1. Dose estimation for paediatric cranial computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Curci Daros, K.A.; Bitelli Medeiros, R. [Sao Paulo Univ. Federal (Brazil); Curci Daros, K.A.; Oliveira Echeimberg, J. de [Centro Univ. Sao Camilo, Sao Paulo (Brazil)

    2006-07-01

    In the last ten years, the number of paediatric computed tomography (CT) scans have increased worldwide, contributing to higher population radiation dose. Technique diversification in paediatrics and different CT equipment technologies have led to various exposure levels complicating precise evaluation of doses and operational conditions necessary for good quality images. The objective of this study was to establish a quantitative relationship between absorbed dose and cranial region in children up to 6 years old undergoing CT exams. Methods: X-ray was measured on the cranial surface of 64 patients undergoing CT using thermoluminescent (T.L.) dosimeters. Forty T.L.D.100 thermoluminescent dosimeters (T.L.D.) were evenly distributed on each patients skin surface along the sagittal axis. Measurements were performed in facial regions exposed to scatter radiation and in the supratentorial and posterior fossa regions, submitted to primary radiation. T.L.D. were calibrated for 120 kV X-ray over the acrylic phantom. T.L. measurements were made with a Harshaw 4000 system. Patient mean T.L. readings were determined for position, pi, of T.L.D. and normalized to the maximum supratentorial reading. From integrating the linear T.L. density function (?) resulting from radiation distribution in each of the three exposed regions, dose fraction was determined in the region of interest, along with total dose under the technical conditions used in that specific exam protocol. For each T.L.D. position along the patient cranium, there were n T.L. measurements with 2% uncertainty due to T.L. reader, and 5% due to thermal treatment of dosimeters. Also, mean T.L. readings and their uncertainties were calculated for each patient at each position, p. Results: Mean linear T.L. density for the region exposed to secondary radiation defined by position, 0.3{<=}p{<=}6 cm, was {rho}((p)=7.9(4)x10{sup -2}+7(5)x10{sup -5}p{sup 4.5(4)} cm{sup -1}; exposed to primary X-ray for the posterior fossa

  2. Acute mediastinitis: multidetector computed tomography findings following cardiac surgery

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Clarissa Aguiar de [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Instituto do Coracao (InCor)]. E-mail: clarissaaguiarm@yahoo.com.br; Baena, Marcos Eduardo da Silva [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Ultrasonography; Uezumi, Kiyomi Kato [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Computed Tomography; Castro, Claudio Campi de [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Magnetic Resonance Imaging; Lucarelli, Claudio Luiz [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Center of Diagnosis; Cerri, Giovanni Guido [Universidade de Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Radiology

    2008-07-15

    Postoperative mediastinitis is defined as an infection of the organs and tissues in the mediastinal space, with an incidence ranging between 0.4% and 5% of cases. This disease severity varies from infection of superficial tissues in the chest wall to fulminant mediastinitis with sternal involvement. Diagnostic criterion for postoperative detection of acute mediastinitis at computed tomography is the presence of fluid collections and gas in the mediastinal space, which might or might not be associated with peristernal abnormalities such as edema of soft tissues, separation of sternal segments with marginal bone resorption, sclerosis and osteomyelitis. Other associated findings include lymphadenomegaly, pulmonary consolidation and pleural/ pericardial effusion. Some of these findings, such as mediastinal gas and small fluid collections can be typically found in the absence of infection, early in the period following thoracic surgery where the effectiveness of computed tomography is limited. After approximately two weeks, computed tomography achieves almost 100% sensitivity and specificity. Patients with clinical suspicion of mediastinitis should be submitted to computed tomography for investigating the presence of fluid collections to identify the extent and nature of the disease. Multidetector computed tomography allows 3D images reconstruction, contributing particularly to the evaluation of the sternum. (author)

  3. Iterative image reconstruction and its role in cardiothoracic computed tomography.

    Science.gov (United States)

    Singh, Sarabjeet; Khawaja, Ranish Deedar Ali; Pourjabbar, Sarvenaz; Padole, Atul; Lira, Diego; Kalra, Mannudeep K

    2013-11-01

    Revolutionary developments in multidetector-row computed tomography (CT) scanner technology offer several advantages for imaging of cardiothoracic disorders. As a result, expanding applications of CT now account for >85 million CT examinations annually in the United States alone. Given the large number of CT examinations performed, concerns over increase in population-based risk for radiation-induced carcinogenesis have made CT radiation dose a top safety concern in health care. In response to this concern, several technologies have been developed to reduce the dose with more efficient use of scan parameters and the use of "newer" image reconstruction techniques. Although iterative image reconstruction algorithms were first introduced in the 1970s, filtered back projection was chosen as the conventional image reconstruction technique because of its simplicity and faster reconstruction times. With subsequent advances in computational speed and power, iterative reconstruction techniques have reemerged and have shown the potential of radiation dose optimization without adversely influencing diagnostic image quality. In this article, we review the basic principles of different iterative reconstruction algorithms and their implementation for various clinical applications in cardiothoracic CT examinations for reducing radiation dose.

  4. Computed tomography and radionuclide brain scanning

    International Nuclear Information System (INIS)

    Lusins, J.O.; Chayes, Z.; Nakagawa, H.

    1980-01-01

    A comparison o CT (computerized Tomography) and radionuclide brain scanning was performed; 30 patients with a total of 42 lesions were evaluated. Previous sreports have shown that CT and radionuclide scanning are equally useful in detecting metastatic disease. However, if contrast enhancement is used we find that computerized tomography is far more accurate than radionuclide scanning in detecting metastatic disease to the brain, 95.4 percent as compared to 62 percent. Our study also shows that radionuclide scanning falls off in accuracy when the the lesion is below 2 cm. in size. Also, the presence of brain edema in association with metastatic disease increases the probability of having a positive nuclear scan finding

  5. Interior tomography: theory, algorithms and applications

    Science.gov (United States)

    Yu, Hengyong; Ye, Yangbo; Wang, Ge

    2008-08-01

    The conventional wisdom states that the interior problem (reconstruction of an interior region from projection data along lines only through that region) is NOT uniquely solvable. While it remains correct, our recent theoretical and numerical results demonstrated that this interior problem CAN be solved in a theoretically exact and numerically stable fashion if a sub-region within the interior region is known. In contrast to the well-established lambda tomography, the studies on this type of exact interior reconstruction are referred to as "interior tomography". In this paper, we will overview the development of interior tomography, involving theory, algorithms and applications. The essence of interior tomography is to find the unique solution from highly truncated projection data via analytic continuation. Such an extension can be done either in the filtered backprojection or backprojection filtration formats. The key issue for the exact interior reconstruction is how to invert the truncated Hilbert transform. We have developed a projection onto convex set (POCS) algorithm and a singular value decomposition (SVD) method and produced excellent results in numerical simulations and practical applications.

  6. Application of synchrotron radiation X-ray computed tomography to investigate the agglomerating behavior of TiB{sub 2} particles in aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei; Mao, Feng; Chen, Zongning; Han, Jingyu; Yan, Guangyuan [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Tongmin, E-mail: tmwang@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Cao, Zhiqiang, E-mail: caozq@dlut.edu.cn [Laboratory of Special Processing of Raw Materials, Dalian University of Technology, Dalian 116024 (China)

    2015-02-15

    Highlights: • SR-CT was a powerful tool to investigate the TiB{sub 2} distribution in Al-TiB{sub 2} in situ composites. • Three kinds of agglomerations frequently present in the composites. • Agglomerations formed via the diffused atoms reacting with intermediate products. • The composites containing agglomerations show a much reduced ductility. - Abstract: Agglomeration of reinforcing particles has a number of deleterious effects on the properties of in situ metal matrix composites (MMCs). In order to better understand this phenomenon, the agglomerating behavior of TiB{sub 2} particles in aluminum based in situ MMCs was investigated using synchrotron radiation X-ray computed tomography (SR-CT) and field emission scanning electron microscope (FESEM). SR-CT was shown to be a powerful tool for visualizing and quantifying the three-dimensional (3D) features within the composites. Based on the SR-CT and FESEM results, a formation mechanism of the flaky agglomerates, flocculent agglomerates and clusters of coarse TiB{sub 2} particles, which are most frequently presented in the in situ Al/TiB{sub 2} composite, has been proposed. The mechanism shows that the formation of these three kinds of agglomerates can be attributed to three parallel processes, i.e. diffusing titanium atoms reacting with AlB{sub 2}, aluminum melt directly reacting with emulsified salt, diffusing boron atoms reacting with TiAl{sub 3}, respectively. Moreover, the mechanism may shed some light on how to design better processing techniques for obtaining homogenous particle distribution in in situ Al/TiB{sub 2} composites in the future.

  7. Application of synchrotron radiation X-ray computed tomography to investigate the agglomerating behavior of TiB2 particles in aluminum

    International Nuclear Information System (INIS)

    Chen, Fei; Mao, Feng; Chen, Zongning; Han, Jingyu; Yan, Guangyuan; Wang, Tongmin; Cao, Zhiqiang

    2015-01-01

    Highlights: • SR-CT was a powerful tool to investigate the TiB 2 distribution in Al-TiB 2 in situ composites. • Three kinds of agglomerations frequently present in the composites. • Agglomerations formed via the diffused atoms reacting with intermediate products. • The composites containing agglomerations show a much reduced ductility. - Abstract: Agglomeration of reinforcing particles has a number of deleterious effects on the properties of in situ metal matrix composites (MMCs). In order to better understand this phenomenon, the agglomerating behavior of TiB 2 particles in aluminum based in situ MMCs was investigated using synchrotron radiation X-ray computed tomography (SR-CT) and field emission scanning electron microscope (FESEM). SR-CT was shown to be a powerful tool for visualizing and quantifying the three-dimensional (3D) features within the composites. Based on the SR-CT and FESEM results, a formation mechanism of the flaky agglomerates, flocculent agglomerates and clusters of coarse TiB 2 particles, which are most frequently presented in the in situ Al/TiB 2 composite, has been proposed. The mechanism shows that the formation of these three kinds of agglomerates can be attributed to three parallel processes, i.e. diffusing titanium atoms reacting with AlB 2 , aluminum melt directly reacting with emulsified salt, diffusing boron atoms reacting with TiAl 3 , respectively. Moreover, the mechanism may shed some light on how to design better processing techniques for obtaining homogenous particle distribution in in situ Al/TiB 2 composites in the future

  8. Three cases with only a small parenchymatous calcified lesion demonstrated by computed tomography. With special reference to the application of the operative procedure

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Akira; Kitahara, Yukio; Sakai, Hideaki

    1987-04-01

    We have experienced three rare cases which revealed only a small parenchymatous calcified lesion, with no perifocal edema, no mass effect and no contrast enhancement on computed tomography (CT). Moreover, none of the three cases were demonstrated by serial angiography. Case 1. A 30-year-old man had had a 4.5-year history of automatism. The physical and neurological examinations revealed no evidence of abnormality. Electric encephalography showed a small, sharp wave and a single spike in the right temporal. A skull tomogram revealed a small calcification in the right temporal. CT showed two small calcific densities in the left inferior temporal gyrus. The calcified lesion was totally resected; histological examinations proved it to be partially thrombosed calcified AVM in which the wall was thin, while hemosiderin was found in the surrounding tissue. Case 2. A 18-year-old man who had had only one attack, a partial, secondary, generalized seizure 4 years before was admitted to our hospital. The physical examinations revealed no evidence of abnormality. A CT scan only demonstrated a small nodular calcification in the surface of the right temporal lobe. Craniotomy was performed, and a small astro-oligo mixed glioma was totally resected. He is currently symptom-free, and his examination results are normal. Case 3. A 58-year-old woman who had developed trunchal ataxia and dysarthria in the preceding 5 months was admitted to our hospital. The neurological examination revealed ataxic dysarthria, a lack of co-ordination on the left side, and trunchal ataxia. A skull plain X-ray and a tomogram revealed a small calcification in the posterior cranial fossa. An angiogram was almost normal. A CT scan revealed only a small calcification in the left cerebellar hemisphere. The histological examinations proved it to be partial thrombosed calcified AVM; a part of the wall was thin and thought to show a tendency to hemorrhage. (J.P.N.).

  9. Applications of interval computations

    CERN Document Server

    Kreinovich, Vladik

    1996-01-01

    Primary Audience for the Book • Specialists in numerical computations who are interested in algorithms with automatic result verification. • Engineers, scientists, and practitioners who desire results with automatic verification and who would therefore benefit from the experience of suc­ cessful applications. • Students in applied mathematics and computer science who want to learn these methods. Goal Of the Book This book contains surveys of applications of interval computations, i. e. , appli­ cations of numerical methods with automatic result verification, that were pre­ sented at an international workshop on the subject in EI Paso, Texas, February 23-25, 1995. The purpose of this book is to disseminate detailed and surveyed information about existing and potential applications of this new growing field. Brief Description of the Papers At the most fundamental level, interval arithmetic operations work with sets: The result of a single arithmetic operation is the set of all possible results as the o...

  10. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Tuberculosis: Spectrum of Manifestations.

    Science.gov (United States)

    Agarwal, Krishan Kant; Behera, Abhishek; Kumar, Rakesh; Bal, Chandrasekhar

    2017-01-01

    The objective of this article is to provide an illustrative tutorial highlighting the utility of 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography ( 18 F-FDG-PET/CT) imaging to detect spectrum of manifestations in patients with tuberculosis (TB). FDG-PET/CT is a powerful tool for early diagnosis, measuring the extent of disease (staging), and consequently for evaluation of response to therapy in patients with TB.

  11. Computer applications in radiology.

    Science.gov (United States)

    Vannier, M W

    1991-04-01

    Computer applications in radiology are evolving rapidly, tied to incremental improvements in hardware, software, and methods. In computer hardware, the emergence of dramatically improved graphic and computational performance for engineering workstations enables their use for visualization. Major changes in networking, storage, and display technology play a major role in influencing applications. The use of three-dimensional digitizers to perform localization of real three-dimensional points in conjunction with images and the rendering of objects using rapid prototyping methods, such as stereolithography, were recently reported. Major software advances have taken place through the availability of applications packages that are operated with menu-driven or point-and-click user interfaces, data flow languages, or complete turnkey applications. Imaging methods including CT, MR imaging, digital radiography, biomagnetism, and optical range sensing, which take advantage of advanced computer technology, are new this year. Image processing for multimodality fusion or image registration, visualization, reconstruction, and quantification of images, have been reported at a wide variety of conferences and in key publications. New computer methods to fabricate custom orthopaedic implants, and to improve imaging technology assessment were introduced.

  12. Evaluation of myocardial ischemia by multiple detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2015-01-15

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  13. Diagnosis of dementia with single photon emission computed tomography

    International Nuclear Information System (INIS)

    Jagust, W.J.; Budinger, T.F.; Reed, B.R.

    1987-01-01

    Single photon emission computed tomography is a practical modality for the study of physiologic cerebral activity in vivo. We utilized single photon emission computed tomography and N-isopropyl-p-iodoamphetamine iodine 123 to evaluate regional cerebral blood flow in nine patients with Alzheimer's disease (AD), five healthy elderly control subjects, and two patients with multi-infarct dementia. We found that all subjects with AD demonstrated flow deficits in temporoparietal cortex bilaterally, and that the ratio of activity in bilateral temporoparietal cortex to activity in the whole slice allowed the differentiation of all patients with AD from both the controls and from the patients with multi-infarct dementia. Furthermore, this ratio showed a strong correlation with disease severity in the AD group. Single photon emission computed tomography appears to be useful in the differential diagnosis of dementia and reflects clinical features of the disease

  14. Utility of the computed tomography indices on cone beam computed tomography images in the diagnosis of osteoporosis in women

    International Nuclear Information System (INIS)

    Koh, Kwang Joon; Kim, Kyung A

    2011-01-01

    This study evaluated the potential use of the computed tomography indices (CTI) on cone beam CT (CBCT) images for an assessment of the bone mineral density (BMD) in postmenopausal osteoporotic women. Twenty-one postmenopausal osteoporotic women and 21 postmenopausal healthy women were enrolled as the subjects. The BMD of the lumbar vertebrae and femur were calculated by dual energy X-ray absorptiometry (DXA) using a DXA scanner. The CBCT images were obtained from the unilateral mental foramen region using a PSR-9000N Dental CT system. The axial, sagittal, and coronal images were reconstructed from the block images using OnDemend3D. The new term 'CTI' on CBCT images was proposed. The relationship between the CT measurements and BMDs were assessed and the intra-observer agreement was determined. There were significant differences between the normal and osteoporotic groups in the computed tomography mandibular index superior (CTI(S)), computed tomography mandibular index inferior (CTI(I)), and computed tomography cortical index (CTCI). On the other hand, there was no difference between the groups in the computed tomography mental index (CTMI: inferior cortical width). CTI(S), CTI(I), and CTCI on the CBCT images can be used to assess the osteoporotic women.

  15. Utility of the computed tomography indices on cone beam computed tomography images in the diagnosis of osteoporosis in women

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kwang Joon; Kim, Kyung A [School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2011-09-15

    This study evaluated the potential use of the computed tomography indices (CTI) on cone beam CT (CBCT) images for an assessment of the bone mineral density (BMD) in postmenopausal osteoporotic women. Twenty-one postmenopausal osteoporotic women and 21 postmenopausal healthy women were enrolled as the subjects. The BMD of the lumbar vertebrae and femur were calculated by dual energy X-ray absorptiometry (DXA) using a DXA scanner. The CBCT images were obtained from the unilateral mental foramen region using a PSR-9000N Dental CT system. The axial, sagittal, and coronal images were reconstructed from the block images using OnDemend3D. The new term 'CTI' on CBCT images was proposed. The relationship between the CT measurements and BMDs were assessed and the intra-observer agreement was determined. There were significant differences between the normal and osteoporotic groups in the computed tomography mandibular index superior (CTI(S)), computed tomography mandibular index inferior (CTI(I)), and computed tomography cortical index (CTCI). On the other hand, there was no difference between the groups in the computed tomography mental index (CTMI: inferior cortical width). CTI(S), CTI(I), and CTCI on the CBCT images can be used to assess the osteoporotic women.

  16. Validation of the Gate simulation platform in single photon emission computed tomography and application to the development of a complete 3-dimensional reconstruction algorithm; Validation de la plate-forme de simulation GATE en tomographie a emission monophotonique et application au developpement d'un algorithme de reconstruction 3D complete

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, D

    2003-10-01

    Monte Carlo simulations are currently considered in nuclear medical imaging as a powerful tool to design and optimize detection systems, and also to assess reconstruction algorithms and correction methods for degrading physical effects. Among the many simulators available, none of them is considered as a standard in nuclear medical imaging: this fact has motivated the development of a new generic Monte Carlo simulation platform (GATE), based on GEANT4 and dedicated to SPECT/PET (single photo emission computed tomography / positron emission tomography) applications. We participated during this thesis to the development of the GATE platform within an international collaboration. GATE was validated in SPECT by modeling two gamma cameras characterized by a different geometry, one dedicated to small animal imaging and the other used in a clinical context (Philips AXIS), and by comparing the results obtained with GATE simulations with experimental data. The simulation results reproduce accurately the measured performances of both gamma cameras. The GATE platform was then used to develop a new 3-dimensional reconstruction method: F3DMC (fully 3-dimension Monte-Carlo) which consists in computing with Monte Carlo simulation the transition matrix used in an iterative reconstruction algorithm (in this case, ML-EM), including within the transition matrix the main physical effects degrading the image formation process. The results obtained with the F3DMC method were compared to the results obtained with three other more conventional methods (FBP, MLEM, MLEMC) for different phantoms. The results of this study show that F3DMC allows to improve the reconstruction efficiency, the spatial resolution and the signal to noise ratio with a satisfactory quantification of the images. These results should be confirmed by performing clinical experiments and open the door to a unified reconstruction method, which could be applied in SPECT but also in PET. (author)

  17. Microstructure of cotton fibrous assemblies based on computed tomography

    Science.gov (United States)

    Jing, Hui; Yu, Weidong

    2017-12-01

    This paper describes for the first time the analysis of inner microstructure of cotton fibrous assemblies using computed tomography. Microstructure parameters such as packing density, fractal dimension as well as porosity including open porosity, closed porosity and total porosity are calculated based on 2D data from computed tomography. Values of packing density and fractal dimension are stable in random oriented fibrous assemblies, and there exists a satisfactory approximate linear relationship between them. Moreover, poles analysis indicates that porosity represents the tightness of fibrous assemblies and open poles are main existence.

  18. Computed tomography of the thorax in children with cystic fibrosis

    International Nuclear Information System (INIS)

    Parente Filho, Livio William Sales; Marchiori, Edson; Daltro, Pedro; Santos, Eloa Nunes

    1998-01-01

    We studied retrospectively the value of computed tomography of the thorax in patients suffering from cystic fibrosis. Twenty-six patients were studied, which showed as the most frequency pulmonary findings bronchial wall thickening in 22 patients (84.6), followed by bronchiectasis in 16 patients (61.5%). Less frequent finding were ill-defined patch consolidation, mucoid impaction, bullaes and atelectasis. We found a predominant distribution of bronchial wall thickening and bronchiectasis in the upper lobes of the lungs. Computed tomography is the more sensitive technique for early visualization and location of the manifestations of cystic fibrosis bronchopathy. (author)

  19. Helical computed tomography and the workstation: introduction to a symbiosis

    International Nuclear Information System (INIS)

    Garcia-Santos, J.M.

    1997-01-01

    We do a brief introduction to the possibilities of an helical computed tomography system when it is associated with a powerful workstation. The fast and volumetric way of acquisition constitutes, basically, the main advantage of this sort of computed tomography. The anatomical and radio pathological study, in a workstation, of the acquired information (thanks to multiplanar and 3D reconstruction), increases significantly our capacity of analysis in each patient. Only the clinical and radiological experience will tell us which is the right place that this symbiosis occupies within our diagnosis tools. (Author) 11 refs

  20. Role of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Diagnostic Evaluation of Carcinoma Urinary Bladder: Comparison with Computed Tomography

    International Nuclear Information System (INIS)

    Chakraborty, Dhritiman; Mittal, Bhagwant Rai; Kashyap, Raghava; Mete, Utham Kumar; Narang, Vikram; Das, Ashim; Bhattacharya, Anish; Khandelwal, Niranjan; Mandal, Arup K.

    2014-01-01

    Bladder carcinoma is the most frequent tumor of the urinary tract and accounts 7% of all malignancies in men and 2% of all malignancies in women. This retrospective study was carried out to assess the diagnostic utility of F18-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the imaging evaluation of bladder carcinoma. Seventy-seven consecutive patients diagnosed to have carcinoma urinary bladder referred for F18-FDG PET/CT were included in this study. Thirty-four patients were for initial staging after transurethral biopsy and remaining 43 patients were for restaging. All patients also underwent CT scan of the abdomen and pelvis. PET/CT findings were correlated with diagnostic CT scan and histopathological findings. In 30 of the 34 patients for initial staging, both PET/CT and CT confirmed the primary lesion in the bladder. Histopathology report was available in 23 patients. Lymph nodes FDG uptake reported to be metastatic in 10/23 patients while CT detected lymph node metastasis in 12 patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy have been calculated to be 87.5%, 80%, 70%, 92%, 82% for PET/CT and 66%, 57%, 50%, 72%, 60% for CT respectively. PET/CT detected metastatic disease in 8 patients whereas CT detected in 4 patients. Of the 43 patients for restaging, local recurrence was detected in 24 patients on both PET/CT and CT. Histopathology report was available in 17 patients. Sensitivity, specificity, PPV, NPV and accuracy were 85%, 60%, 60%, 85%, 70% for PET/CT and 80%, 50%, 40%, 85%, 58% for CT respectively. Nineteen patients were detected to have metastatic disease by PET/CT, whereas CT detected metastases in 11 patients. F-18 FDG PET/CT is a very useful modality in pre-operative staging and monitoring after surgery, chemotherapy or radiotherapy of patients with carcinoma urinary bladder

  1. Practical limitations of cone-beam computed tomography in 3D cephalometry

    NARCIS (Netherlands)

    Damstra, Janalt; Fourie, Zacharias; Ren, Yijin

    2011-01-01

    3D cone beam computed tomography (CBCT) images offer a unique and new appreciation of the anatomical structures and underlying anomalies not possible with conventional radiographs. However, in almost all aspects of CBCT imaging, from utilization to application, inherent limitations and pitfalls

  2. Feasibility Study of Computational Fluid Dynamics Simulation of Coronary Computed Tomography Angiography Based on Dual-Source Computed Tomography.

    Science.gov (United States)

    Lu, Jing; Yu, Jie; Shi, Heshui

    2017-01-01

    Adding functional features to morphological features offers a new method for non-invasive assessment of myocardial perfusion. This study aimed to explore technical routes of assessing the left coronary artery pressure gradient, wall shear stress distribution and blood flow velocity distribution, combining three-dimensional coronary model which was based on high resolution dual-source computed tomography (CT) with computational fluid dynamics (CFD) simulation. Three cases of no obvious stenosis, mild stenosis and severe stenosis in left anterior descending (LAD) were enrolled. Images acquired on dual-source CT were input into software Mimics, ICEMCFD and FLUENT to simulate pressure gradient, wall shear stress distribution and blood flow velocity distribution. Measuring coronary enhancement ratio of coronary artery was to compare with pressure gradient. Results conformed to theoretical values and showed difference between normal and abnormal samples. The study verified essential parameters and basic techniques in blood flow numerical simulation preliminarily. It was proved feasible.

  3. USE OF COMPUTED TOMOGRAPHY FOR INVESTIGATION OF HEPATIC LIPIDOSIS IN CAPTIVE CHELONOIDIS CARBONARIA (SPIX, 1824).

    Science.gov (United States)

    Marchiori, Adriano; da Silva, Ieverton Cleiton Correia; de Albuquerque Bonelli, Marília; de Albuquerque Zanotti, Luciana Carla Rameh; Siqueira, Daniel B; Zanotti, Alexandre Pinheiro; Costa, Fabiano Séllos

    2015-06-01

    Computed tomography is a sensitive and highly applicable technique for determining the degree of radiographic attenuation of the hepatic parenchyma. Radiodensity measurements of the liver can help in the diagnosis of hepatic lipidosis in humans and animals. The objective was to investigate the presence of hepatic lipidosis in captive red-footed tortoises (Chelonoidis carbonaria) using computed tomography. Computed tomography was performed in 10 male red-footed tortoises. Mean radiographic attenuation values for the hepatic parenchyma were 11.2±3.0 Hounsfield units (HU). Seven red-footed tortoises had values lower than 20 HU, which is compatible with C. carbonaria hepatic lipidosis. These results allowed an early diagnosis of the hepatic changes and suggested corrective measures regarding feeding and management protocols.

  4. Micro-computer tomography and a renaissance of insect morphology

    Science.gov (United States)

    Friedrich, Frank; Beutel, Rolf G.

    2008-08-01

    The use of new technologies, especially computer-based three dimensional reconstructions and micro-computer tomography (μ-CT) have greatly improved and facilitated the detailed investigation of insect anatomy. Optimal results in morphological work aiming at phylogenetic reconstruction can be obtained with a combined application of different techniques such as histology, scanning electron microscopy, and μ-CT. The use of μ-CT greatly enhances the efficiency of the acquisition of detailed anatomical data and allows a broad taxon sampling in phylogenetic studies partly or entirely based on morphological characters. A disadvantage of phase contrasted μ-CT images is the poor differentiation of different tissue types. This problem can be overcome by the use of stable low energy photon beams as available at the beamline BW2 of the Deutsches Elektronen-Synchrotron in Hamburg (DESY). Synchrotron-radiation-based μ-CT data (SR μ-CT) obtained with this approach are an ideal basis for highly efficient three dimensional reconstructions of high quality.

  5. Image reconstruction in transcranial photoacoustic computed tomography of the brain

    Science.gov (United States)

    Mitsuhashi, Kenji; Wang, Lihong V.; Anastasio, Mark A.

    2015-03-01

    Photoacoustic computed tomography (PACT) holds great promise for transcranial brain imaging. However, the strong reflection, scattering, attenuation, and mode-conversion of photoacoustic waves in the skull pose serious challenges to establishing the method. The lack of an appropriate model of solid media in conventional PACT imaging models, which are based on the canonical scalar wave equation, causes a significant model mismatch in the presence of the skull and thus results in deteriorated reconstructed images. The goal of this study was to develop an image reconstruction algorithm that accurately models the skull and thereby ameliorates the quality of reconstructed images. The propagation of photoacoustic waves through the skull was modeled by a viscoelastic stress tensor wave equation, which was subsequently discretized by use of a staggered grid fourth-order finite-difference time-domain (FDTD) method. The matched adjoint of the FDTD-based wave propagation operator was derived for implementing a back-projection operator. Systematic computer simulations were conducted to demonstrate the effectiveness of the back-projection operator for reconstructing images in a realistic three-dimensional PACT brain imaging system. The results suggest that the proposed algorithm can successfully reconstruct images from transcranially-measured pressure data and readily be translated to clinical PACT brain imaging applications.

  6. Industrial Computed Tomography using Proximal Algorithm

    KAUST Repository

    Zang, Guangming

    2016-04-14

    In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

  7. Computed tomography of cystic pancreatic fibrosis

    International Nuclear Information System (INIS)

    Brachlow, M.; Zaunbauer, W.; Haertel, M.

    1984-01-01

    The computer tomographic appearances of atrophic and lipomatous degeneration of the pancreas in cystic pancreatic fibrosis are described. CT exploration of the pancreas in recommended, particularly in differential diagnostic aspects of cystic fibrosis. (orig.) [de

  8. Features and applications of positron emission tomography

    International Nuclear Information System (INIS)

    Fan Mingwu

    1997-01-01

    Positron emission tomography, the so-called world's smartest camera, is based on a NaI or BGO detector and imaging of positron-emitting radioisotopes which are introduced as a tracer into the regional tissue or organ of interest. With the aid of a computer visual images of a series of these distributions can be built into a picture of the functional status of the tissue or organ being imaged. This highly accurate imaging technique is already widely used for clinical diagnostics heart disease, brain disorder, tumors and so on

  9. [Basic principles of flat detector computed tomography (FD-CT)].

    Science.gov (United States)

    Kyriakou, Y; Struffert, T; Dörfler, A; Kalender, W A

    2009-09-01

    Flat detectors (FDs) have been developed for use in radiography and fluoroscopy to replace standard X-ray film, film-screen combinations and image intensifiers (II). In comparison to X-ray film and II, FD technology offers higher dynamic range, dose reduction, fast digital readout and the possibility for dynamic acquisitions of image series, yet keeping to a compact design. It appeared logical to employ FD designs also for computed tomography (CT) imaging. FDCT has meanwhile become widely accepted for interventional and intra-operative imaging using C-arm systems. Additionally, the introduction of FD technology was a milestone for soft-tissue CT imaging in the interventional suite which was not possible with II systems in the past. This review focuses on technical and performance issues of FD technology and its wide range of applications for CT imaging. FDCT is not aimed at challenging standard clinical CT as regards to the typical diagnostic examinations, but it has already proven unique for a number of dedicated CT applications offering distinct practical advantages, above all the availability of immediate CT imaging during an intervention.

  10. Basics principles of flat detector computed tomography (FD-CT)

    International Nuclear Information System (INIS)

    Kyriakou, Y.; Struffert, T.; Doerfler, A.; Kalender, W.A.

    2009-01-01

    Flat detectors (FDs) have been developed for use in radiography and fluoroscopy to replace standard X-ray film, film-screen combinations and image intensifiers (II). In comparison to X-ray film and II, FD technology offers higher dynamic range, dose reduction, fast digital readout and the possibility for dynamic acquisitions of image series, yet keeping to a compact design. It appeared logical to employ FD designs also for computed tomography (CT) imaging. FDCT has meanwhile become widely accepted for interventional and intra-operative imaging using C-arm systems. Additionally, the introduction of FD technology was a milestone for soft-tissue CT imaging in the interventional suite which was not possible with II systems in the past. This review focuses on technical and performance issues of FD technology and its wide range of applications for CT imaging. FDCT is not aimed at challenging standard clinical CT as regards to the typical diagnostic examinations, but it has already proven unique for a number of dedicated CT applications offering distinct practical advantages, above all the availability of immediate CT imaging during an intervention. (orig.) [de

  11. Automatic Solitary Lung Nodule Detection in Computed Tomography Images Slices

    Science.gov (United States)

    Sentana, I. W. B.; Jawas, N.; Asri, S. A.

    2018-01-01

    Lung nodule is an early indicator of some lung diseases, including lung cancer. In Computed Tomography (CT) based image, nodule is known as a shape that appears brighter than lung surrounding. This research aim to develop an application that automatically detect lung nodule in CT images. There are some steps in algorithm such as image acquisition and conversion, image binarization, lung segmentation, blob detection, and classification. Data acquisition is a step to taking image slice by slice from the original *.dicom format and then each image slices is converted into *.tif image format. Binarization that tailoring Otsu algorithm, than separated the background and foreground part of each image slices. After removing the background part, the next step is to segment part of the lung only so the nodule can localized easier. Once again Otsu algorithm is use to detect nodule blob in localized lung area. The final step is tailoring Support Vector Machine (SVM) to classify the nodule. The application has succeed detecting near round nodule with a certain threshold of size. Those detecting result shows drawback in part of thresholding size and shape of nodule that need to enhance in the next part of the research. The algorithm also cannot detect nodule that attached to wall and Lung Chanel, since it depend the searching only on colour differences.

  12. Tracheo-oesophageal fistula diagnosed with multidetector computed tomography.

    LENUS (Irish Health Repository)

    Hodnett, Pa

    2009-04-01

    This case highlights important issues in investigation of patients with suspected tracheo-oesophageal fistula including the value of multidetector computed tomography, the importance of thorough imaging evaluation when high clinical suspicion of tracheo-oesophageal fistula exists and the value of close interaction between radiologists and intensive care physicians in the investigation of these patients.

  13. An Easily Assembled Laboratory Exercise in Computed Tomography

    Science.gov (United States)

    Mylott, Elliot; Klepetka, Ryan; Dunlap, Justin C.; Widenhorn, Ralf

    2011-01-01

    In this paper, we present a laboratory activity in computed tomography (CT) primarily composed of a photogate and a rotary motion sensor that can be assembled quickly and partially automates data collection and analysis. We use an enclosure made with a light filter that is largely opaque in the visible spectrum but mostly transparent to the near…

  14. Computed tomography of the orbit - A review and an update.

    Science.gov (United States)

    Tawfik, Hatem A; Abdelhalim, Ahmed; Elkafrawy, Mamdouh H

    2012-10-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) of the orbit have been competing for the hearts and minds of health care providers for well over 2 decades. While several drawbacks pertaining to CT have been outlined since the introduction of MRI, CT remains the standard diagnostic test for evaluating cross-sectional, 2 or 3-dimensional images of the body.

  15. Multidetector computed tomography of jaw lesions in children and adolescents

    International Nuclear Information System (INIS)

    Gadodia, A.; Seith, A.; Sharma, R.; Choudhury, A.R.; Bhutia, O.; Gupta, A.

    2010-01-01

    Full text: Jaw lesions in paediatric and adolescent population are uncommon and can arise in odontogenic or non-odontogenic tissues. With the advent of multidetector computed tomography (MDCT), algorithm for imaging jaw lesions has changed dramatically. This pictorial essay describes the imaging appearance of commonly encountered jaw lesions in children and adolescents with emphasis on MDCT findings

  16. Computed tomography of the gastro-intestinal tract : its value

    International Nuclear Information System (INIS)

    Reeders, J.W.A.J.

    1995-01-01

    The subject discussed include indications and accuracy of CT - computed tomography, technical considerations, common pitfalls in CT interpretation, parameters for CT evaluation, benign lesions, double halo and target signs, hyperattenuated, inflammatory bowel disease, intestinal ischaemia, primary adenocarcinoma of the GIT, lymphoma and leiomyosarcoma (3 refs.)

  17. Multi-detector computed tomography radiation doses in the follow ...

    African Journals Online (AJOL)

    2014-05-09

    May 9, 2014 ... (CT) scans without prior consultation with a radiologist in order to increase efficiency in light of human resource constraints. As a result ... smart phone or mobile device to read online. Read online: Background: Multi-detector computed tomography (MDCT) is the preferred modality for follow-up of paediatric ...

  18. A survey of computed tomography imaging techniques and patient ...

    African Journals Online (AJOL)

    Objectives: To assess the level of patient dose in Computed Tomography examination in Kenya, compare with the international diagnostic reference levels and establish the initial national diagnostic reference levels. Design: The patient doses for brain, chest, abdomen and pelvis examinations were assessed using typical ...

  19. Computed Tomography of Patients with Head Trauma following ...

    African Journals Online (AJOL)

    METHODS: Retrospective analysis of cranial computed tomography (CT) films, request cards, duplicate copy of radiology reports, soft copy CT images and case notes of 61 patients who underwent cranial CT scan on account of road traffic accidents. The study CT scans were performed at the radiology department of ...

  20. Routine Cranial Computed Tomography before Lumbar Puncture in ...

    African Journals Online (AJOL)

    Background: Current international guidelines recommend that a cranial computed tomography (CT) be performed on all HIV-positive patients presenting with new onset seizures, before a lumbar puncture (LP) is performed. In the South African setting, however this delay could be life threatening. The present study sought to ...

  1. Computed tomography features of head injury in Ghanaian children ...

    African Journals Online (AJOL)

    Background: Injuries to the head are common in children. There are several reports in literature of head injury and evaluation with computed tomography scan (CT scan) but only a few focus on children. Method: A retrospective review of films and reports of the CT scans of 41 children with head injury. Results: Positive CT ...

  2. Documentation of the ISA Micro Computed Tomography System

    Energy Technology Data Exchange (ETDEWEB)

    Brown, William D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, Jerel A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-12-18

    This document is intended to provide information on the ISA Micro Computed Tomography (MicroCT) system that will be installed in Yavne, Israel. X-ray source, detector, and motion control hardware are specified as well as specimen platforms, containers, and reference material types. Most of the details on the system are derived from Reference 1 and 2.

  3. Unsuspected organic disease in chronic schizophrenia demonstrated by computed tomography

    International Nuclear Information System (INIS)

    Cunningham Owens, D.G.; Johnstone, E.C.; Bydder, G.M.; Kreel, L.

    1980-01-01

    Unsuspected intracranial pathology was demonstrated in 12 of 136 chronic schizophrenic patients examined by computed tomography (CT). Seven cases of cerebral infarction were found, and one each of porencephalic cyst, meningioma, cystic enlargement of the pineal body, and two of subdural haematoma. Attention is drawn to the value of CT in demonstrating organic disease in schizophrenia. (author)

  4. Computed tomography evaluation of autogenous graft in sinus lift surgery

    International Nuclear Information System (INIS)

    Ajzen, Sergio Aron; Moscatiello, Rafael Andrade; Lima, Aida Maria Custodio de; Moscatiello, Vitoria Aparecida Muglia; Helio Kiitiro Yamashita; Mosacatiello, Rafael Muglia; Nishiguchi, Celso Itiro; Alves, Maria Teresa de Seixas

    2001-01-01

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  5. Geometrical metrology on silicone rubber by computed tomography

    DEFF Research Database (Denmark)

    Müller, Pavel; Pacurar, Ramona Alexandra; De Chiffre, Leonardo

    2011-01-01

    Computed tomography (CT) represents a suitable measuring technique for investigation of deformable materials, since no forces are developed on the part during scanning. As for any other measuring instruments, the traceability of the CT scanners needs to be assured. An investigation on geometrical...

  6. Electron beam computed tomography for the diagnosis of cardiac ...

    African Journals Online (AJOL)

    Electron beam computed tomography (EBCT) of the heart is a new modality which will alter the way cardiology is practised. It allows for the detection of early coronary artery disease (CAD) in asymptomatic individuals, regardless of their level of risk as assessed by traditional risk factor analysis. Compared with risk analysis ...

  7. Computed tomography of von Meyenburg complex simulating micro-abscesses

    International Nuclear Information System (INIS)

    Sada, P.N.; Ramakrishna, B.

    1994-01-01

    A case is presented of a bile duct hamartoma in a 44 year old man being evaluated for abdominal pain. The computed tomography (CT) findings suggested micro-abscesses in the liver and a CT guided tru-cut biopsy showed von Meyenburg complex. 9 refs., 3 figs

  8. The utility of computed tomography for diagnosis of intraabdominal abscess

    International Nuclear Information System (INIS)

    Kohno, Kenichi; Takahashi, Toshio; Tamakawa, Yoshiharu

    1981-01-01

    Prompt treatment is necessary for postoperative intraabdominal absecss with accurate diagnosis. Computed Tomography (CT) developed as a new diagnostic imaging procedure revealed to be able to make early diagnosis of intraabdominal abscess after surgery. This paper presented six patients with intraabdominal abscess and discussed the utility of CT diagnosis of the abdominal abscess. (author)

  9. Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

    OpenAIRE

    Yao, Junjie; Xia, Jun; Maslov, Konstantin I.; Nasiriavanaki, Mohammadreza; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

    2012-01-01

    We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood–brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for ...

  10. Quantification of salt concentrations in cured pork by computed tomography

    DEFF Research Database (Denmark)

    Vestergaard, Christian Sylvest; Risum, Jørgen; Adler-Nissen, Jens

    2004-01-01

    Eight pork loin samples were mounted in Plexiglas cylinders and cured for five days. Samples were scanned by computed tomography (CT) once every 24 h. At the end of the experiment, the cylinders were cut in 1 cm sections and analyzed for chloride. From image analysis of the CT images, concentration...

  11. Cost-effectiveness of PET and PET/Computed Tomography

    DEFF Research Database (Denmark)

    Gerke, Oke; Hermansson, Ronnie; Hess, Søren

    2015-01-01

    measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer...

  12. Systematic Errors in Dimensional X-ray Computed Tomography

    DEFF Research Database (Denmark)

    that it is possible to compensate them. In dimensional X-ray computed tomography (CT), many physical quantities influence the final result. However, it is important to know which factors in CT measurements potentially lead to systematic errors. In this talk, typical error sources in dimensional X-ray CT are discussed...

  13. ORIGINAL ARTICLE ORIG ORIG Is computed tomography of the ...

    African Journals Online (AJOL)

    As a predictor of outcome, scores of 13 to 15 are considered to correspond with mild injury, 9 to 12 with moderate injury and 8 or lower with severe injury.1-3. Since the advent of computed tomography (CT) scans in the early. 1970s, the demand from emergency room physicians for CT scans for minor head injury patients is ...

  14. Variability of four-dimensional computed tomography patient models

    NARCIS (Netherlands)

    Sonke, Jan-Jakob; Lebesque, Joos; van Herk, Marcel

    2008-01-01

    PURPOSE: To quantify the interfractional variability in lung tumor trajectory and mean position during the course of radiation therapy. METHODS AND MATERIALS: Repeat four-dimensional (4D) cone-beam computed tomography (CBCT) scans (median, nine scans/patient) routinely acquired during the course of

  15. Quantitative 3-Dimensional Computed Tomography Measurements of Coronoid Fractures

    NARCIS (Netherlands)

    Mellema, Jos J.; Janssen, Stein J.; Guitton, Thierry G.; Ring, David

    2015-01-01

    Purpose Using quantitative 3-dimensional computed tomography (Q3DCT) modeling, we tested the null hypothesis that there was no difference in fracture fragment volume, articular surface involvement, and number of fracture fragments between coronoid fracture types and patterns of traumatic elbow

  16. Cerebral computed tomography in newborn children with large retinal hemmorrhage

    International Nuclear Information System (INIS)

    Skalpe, I.O.; Egge, K.; Maltau, J.M.

    1982-01-01

    Cerebral computed tomography was performed in 10 neonates with large retinal hemorrhage compared with a control group of 10 full-term neonates without such hemorrhage. No signs of intracranial hemorrhage were found. The cerebral ventricles were poorly visualized in both groups. Periventricular low attenuation areas was a frequent finding in both groups. (orig.)

  17. The value of computed tomography-urography in predicting the ...

    African Journals Online (AJOL)

    Background The natural course of pelviureteric junction (PUJ) obstruction is variable. Of those who require surgical intervention, there is no definite reliable preoperative predictor of the likely postoperative outcome. We evaluated the value of preoperative computed tomography (CT)-urography in predicting the ...

  18. Computed tomography: Will the slices reveal the truth

    Science.gov (United States)

    Haridas, Harish; Mohan, Abarajithan; Papisetti, Sravanthi; Ealla, Kranti K. R.

    2016-01-01

    With the advances in the field of imaging sciences, new methods have been developed in dental radiology. These include digital radiography, density analyzing methods, cone beam computed tomography (CBCT), magnetic resonance imaging, ultrasound, and nuclear imaging techniques, which provide high-resolution detailed images of oral structures. The current review aims to critically elaborate the use of CBCT in endodontics. PMID:27652253

  19. Computed Tomography Features of Spontaneously Perforated Pyometra: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.S.; Tan, C.K.; Mak, C.W.; Chia, C.C.; Kuo, C.Y.; Yu, W.L. [Chi-Mei Medical Center, Tainan, Taiwan (China). Depts. of Intensive Care Medicine, Radiology, Obstetrics and Gynecology, and Surgery

    2006-03-15

    Spontaneous perforation of pyometra is an extremely rare emergent gynecologic disease. We report a 73-year-old woman with a spontaneously perforated pyometra presenting with acute abdomen in the emergency department. A dedicated computed tomography examination of the abdominal and pelvic regions revealed the diagnosis. The patient recovered well after surgical intervention and antibiotic treatment.

  20. Coronary artery fly-through using electron beam computed tomography

    NARCIS (Netherlands)

    van Ooijen, P M; Oudkerk, M; van Geuns, R J; Rensing, B J; de Feyter, P J

    2000-01-01

    BACKGROUND: Virtual reality techniques have recently been introduced into clinical medicine. This study examines the possibility of coronary artery fly-through using a dataset obtained by noninvasive coronary angiography with contrast-enhanced electron-beam computed tomography. METHODS AND RESULTS: