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Sample records for computerized tomography images

  1. Computerized tomography

    International Nuclear Information System (INIS)

    Rubashov, I.B.

    1985-01-01

    Operating principle is described for the devices of computerized tomography used in medicine for diagnosis of brain diseases. Computerized tomography is considered as a part of computerized diagnosis, as a part of information science. It is shown that computerized tomography is a real existed field of investigations in medicine and industrial production

  2. Use of computerized tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tjoerstad, K.

    1992-01-01

    This is a neurologist's opinion on how computerized tomography and magnetic resonance imaging have improved the doctor's diagnostic possibilities, changed patient/doctor relationship and increased the patients' expectations from diagnostic tests. How should the often conflicting interests of patients, society and doctors be handled? 15 refs., 1 fig., 1 tab

  3. Morphological analysis of the vestibular aqueduct by computerized tomography images

    International Nuclear Information System (INIS)

    Marques, Sergio Ricardo; Smith, Ricardo Luiz; Isotani, Sadao; Alonso, Luis Garcia; Anadao, Carlos Augusto; Prates, Jose Carlos; Lederman, Henrique Manoel

    2007-01-01

    Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm 2 of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm 2 , 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant

  4. Some aspects of evaluation of image quality in computerized tomography

    International Nuclear Information System (INIS)

    Travassos, Paulo Cesar Baptista; Peixoto, Jose Guilherme; Almeida, Carlos Eduardo Veloso de; Campos, Luciana Tourinho; Magalhaes, Luis Alexandre

    2016-01-01

    The evaluation of CT scanners image quality includes measuring the Hounsfield values, HU, using a table with the limit values. This table does not consider that different devices have different effective energies, which may cause some false results. The evaluation of 90 computerized tomography, by the American College Radiology methodology, showed that some failed devices in the evaluation showed excellent linear fit between the values of the linear attenuation coefficients calculated for the actual energy used, according to the HU values. The analysis of the coefficient of determination suggests that 10 of these devices could have been approved. (author)

  5. Image reconstruction in computerized tomography using the convolution method

    International Nuclear Information System (INIS)

    Oliveira Rebelo, A.M. de.

    1984-03-01

    In the present work an algoritin was derived, using the analytical convolution method (filtered back-projection) for two-dimensional or three-dimensional image reconstruction in computerized tomography applied to non-destructive testing and to the medical use. This mathematical model is based on the analytical Fourier transform method for image reconstruction. This model consists of a discontinuous system formed by an NxN array of cells (pixels). The attenuation in the object under study of a colimated gamma ray beam has been determined for various positions and incidence angles (projections) in terms of the interaction of the beam with the intercepted pixels. The contribution of each pixel to beam attenuation was determined using the weight function W ij which was used for simulated tests. Simulated tests using standard objects with attenuation coefficients in the range of 0,2 to 0,7 cm -1 were carried out using cell arrays of up to 25x25. One application was carried out in the medical area simulating image reconstruction of an arm phantom with attenuation coefficients in the range of 0,2 to 0,5 cm -1 using cell arrays of 41x41. The simulated results show that, in objects with a great number of interfaces and great variations of attenuation coefficients at these interfaces, a good reconstruction is obtained with the number of projections equal to the reconstruction matrix dimension. A good reconstruction is otherwise obtained with fewer projections. (author) [pt

  6. Computerized tomography

    International Nuclear Information System (INIS)

    1980-01-01

    Improvements in the design of computerized tomographic X-ray equipment are described which lead to improvements in the mechanical properties, speed and size of scanning areas. The method envisages the body being scanned as a two-dimensional matrix of elements arising from a plurality of concentric rings. The concentric centre need not coincide with the axis of rotation. The procedures for rotation of the X-ray beam and detectors around the patient and for translating the measured information into attenuation coefficients for each matrix element of the body are described in detail. Explicit derivations are given for the mathematical formulae used. (U.K.)

  7. Computerized tomography

    International Nuclear Information System (INIS)

    Caille, J.M.; Salamon, G.

    1980-01-01

    As X-ray Ct becomes more commonplace, other techniques of investigation using roughly comparable hardware and software have appeared. Positron-Emission Tomography already provides indispensable physiological and physio-pathological information. Similarly, in the histo-chemical field, Nuclear Magnetic Resonance seems very promising. Some of these new techniques will no doubt shortly be considered as essential as CT in establishing accurate diagnoses non-invasively. (orig./VJ) [de

  8. A computerized tomography system for transcranial ultrasound imaging.

    Science.gov (United States)

    Tang, Sai Chun; Clement, Gregory T

    Hardware for tomographic imaging presents both challenge and opportunity for simplification when compared with traditional pulse-echo imaging systems. Specifically, point diffraction tomography does not require simultaneous powering of elements, in theory allowing just a single transmit channel and a single receive channel to be coupled with a switching or multiplexing network. In our ongoing work on transcranial imaging, we have developed a 512-channel system designed to transmit and/or receive a high voltage signal from/to arbitrary elements of an imaging array. The overall design follows a hierarchy of modules including a software interface, microcontroller, pulse generator, pulse amplifier, high-voltage power converter, switching mother board, switching daughter board, receiver amplifier, analog-to-digital converter, peak detector, memory, and USB communication. Two pulse amplifiers are included, each capable of producing up to 400Vpp via power MOSFETS. Switching is based around mechanical relays that allow passage of 200V, while still achieving switching times of under 2ms, with an operating frequency ranging from below 100kHz to 10MHz. The system is demonstrated through ex vivo human skulls using 1MHz transducers. The overall system design is applicable to planned human studies in transcranial image acquisition, and may have additional tomographic applications for other materials necessitating a high signal output.

  9. Vector entropy imaging theory with application to computerized tomography

    International Nuclear Information System (INIS)

    Wang Yuanmei; Cheng Jianping; Heng, Pheng Ann

    2002-01-01

    Medical imaging theory for x-ray CT and PET is based on image reconstruction from projections. In this paper a novel vector entropy imaging theory under the framework of multiple criteria decision making is presented. We also study the most frequently used image reconstruction methods, namely, least square, maximum entropy, and filtered back-projection methods under the framework of the single performance criterion optimization. Finally, we introduce some of the results obtained by various reconstruction algorithms using computer-generated noisy projection data from the Hoffman phantom and real CT scanner data. Comparison of the reconstructed images indicates that the vector entropy method gives the best in error (difference between the original phantom data and reconstruction), smoothness (suppression of noise), grey value resolution and is free of ghost images. (author)

  10. Region-of-interest imaging in cone beam computerized tomography

    International Nuclear Information System (INIS)

    Tam, K.C.

    1996-01-01

    Imaging a sectional region within an object with a detector just big enough to cover the sectional region-of-interest is analyzed. We show that with some suitable choice of scanning configuration and with an innovative method of data combination, all the Radon data can be obtained accurately. The algorithm is mathematically exact, and requires no iterations and no additional measurements. The method can be applied to inspect portions of large industrial objects in industrial imaging, as well as to image portions of human bodies in medical diagnosis

  11. Celebral computerized tomography

    International Nuclear Information System (INIS)

    Lofteroed, B.; Sortland, O.

    1985-01-01

    Indications for cerebral computerized tomography (CT) and the diagnostic results from this examination are evaluated in 127 children. Pathological changes were found in 31 children, mostly based on such indications as increasing head size, suspicion of brain tumor, cerebral paresis, delayed psychomotor development and epileptic seizures. A list of indications for CT in children is given

  12. VARIABILITY OF MANUAL AND COMPUTERIZED METHODS FOR MEASURING CORONAL VERTEBRAL INCLINATION IN COMPUTED TOMOGRAPHY IMAGES

    Directory of Open Access Journals (Sweden)

    Tomaž Vrtovec

    2015-06-01

    Full Text Available Objective measurement of coronal vertebral inclination (CVI is of significant importance for evaluating spinal deformities in the coronal plane. The purpose of this study is to systematically analyze and compare manual and computerized measurements of CVI in cross-sectional and volumetric computed tomography (CT images. Three observers independently measured CVI in 14 CT images of normal and 14 CT images of scoliotic vertebrae by using six manual and two computerized measurements. Manual measurements were obtained in coronal cross-sections by manually identifying the vertebral body corners, which served to measure CVI according to the superior and inferior tangents, left and right tangents, and mid-endplate and mid-wall lines. Computerized measurements were obtained in two dimensions (2D and in three dimensions (3D by manually initializing an automated method in vertebral centroids and then searching for the planes of maximal symmetry of vertebral anatomical structures. The mid-endplate lines were the most reproducible and reliable manual measurements (intra- and inter-observer variability of 0.7° and 1.2° standard deviation, SD, respectively. The computerized measurements in 3D were more reproducible and reliable (intra- and inter-observer variability of 0.5° and 0.7° SD, respectively, but were most consistent with the mid-wall lines (2.0° SD and 1.4° mean absolute difference. The manual CVI measurements based on mid-endplate lines and the computerized CVI measurements in 3D resulted in the lowest intra-observer and inter-observer variability, however, computerized CVI measurements reduce observer interaction.

  13. Highly resolving computerized tomography

    International Nuclear Information System (INIS)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions. (BWU) [de

  14. Highly resolving computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions.

  15. Effect of The Measuring Parameters on The Reconstructed Images by Computerized Tomography

    International Nuclear Information System (INIS)

    Ali, A.M.; Ali, A.M.; Megahid, R.M.

    2011-01-01

    In this paper, the potential of computerized tomography by neutrons and gamma rays as a main precise technique for nondestructive assay of materials and components of prime importance in nuclear and general industries are given and discussed. Both Fast Fourier Transform (FFT) and convolution techniques are introduced. Shepp and Logan human head phantom is used for theoretical testing and studying the effect of translation value for both techniques. Moreover, the effect of the projection number discussed. Comparison between the two reconstruction techniques wasper formed for the examined object. In addition, some of the experimentally scanned images using slit beam of gamma rays emitt ed from the ETRR- 1 reactor are presented and discussed.

  16. Computerized detection of acute ischemic stroke in brain computed tomography images

    International Nuclear Information System (INIS)

    Nagashima, Hiroyuki; Shiraishi, Akihisa; Harakawa, Tetsumi; Shiraishi, Junji; Doi, Kunio; Sunaga, Shinichi

    2009-01-01

    The interpretation of acute ischemic stroke (AIS) in computed tomography (CT) images is a very difficult challenge for radiologists. To assist radiologists in CT image interpretation, we have developed a computerized method for the detection of AIS using 100 training cases and 60 testing cases. In our computerized method, the inclination of the isotropic brain CT volume data is corrected by rotation and shifting. The subtraction data for the contralateral volume is then derived by subtraction from the mirrored (right-left reversed) volume data. Initial candidates suspected to have experienced AIS were identified using multiple-thresholding and filtering techniques. Twenty-one image features of these candidates were extracted and applied to a rule-based test to identify final candidates for AIS. The detection sensitivity values for the training cases and for the testing cases were 95.0% with 3.1 false positives per case and 85.7% with 3.4 false positives per case, respectively. Our computerized method showed good performance in the detection of AIS by CT and is expected to be useful in decision-making by radiologists. (author)

  17. Quantitative inspection by computerized tomography

    International Nuclear Information System (INIS)

    Lopes, R.T.; Assis, J.T. de; Jesus, E.F.O. de

    1989-01-01

    The computerized Tomography (CT) is a method of nondestructive testing, that furnish quantitative information, that permit the detection and accurate localization of defects, internal dimension measurement, and, measurement and chart of the density distribution. The CT technology is much versatile, not presenting restriction in relation to form, size or composition of the object. A tomographic system, projected and constructed in our laboratory is presented. The applications and limitation of this system, illustrated by tomographyc images, are shown. (V.R.B.)

  18. Computerized tomography and its diagnostic value in the imaging of limbs

    International Nuclear Information System (INIS)

    Myllylae, V.; Tervonen, O.; Paeivaensalo, M.; Jalovaara, P.; Merikanto, J.; Maekaeraeinen, H.; Oulu Univ.

    1987-01-01

    The application of computerized tomography in skeletal diagnostics has many advantages over plain film radiography. Its use as a supplementary technique in traumatology and oncology is strongly advised. (orig.) [de

  19. Computerized tomography. Fundamentals, equipment, image quality, applications. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Kalender, W.A.

    2006-01-01

    The book provides a clear and user-oriented outline of the theoretical and technical fundamentals of computerized tomography for a wide range of readers, from conventional CT to volume CT with conical beams. Image quality, its relevant influencing parameters and the performance factors to be observed for clinical application are discussed in detail, as are dose requirements, dose metering and dose reduction measures in CT. The second, revised edition contains updated information and also presents new technologies. A CD-ROM with attractive exemplary appications, animations and interactive exercises in image interpretation and manipulation is included. The book addresses everyone concerned with CT, either in their daily routine or even only every now and then, i.e. physicians, medical assistants, engineers, technicians and physicists. The book also contains a glossary of technical terms. (orig.)

  20. A high-speed computerized tomography image reconstruction using direct two-dimensional Fourier transform method

    International Nuclear Information System (INIS)

    Niki, Noboru; Mizutani, Toshio; Takahashi, Yoshizo; Inouye, Tamon.

    1983-01-01

    The nescessity for developing real-time computerized tomography (CT) aiming at the dynamic observation of organs such as hearts has lately been advocated. It is necessary for its realization to reconstruct the images which are markedly faster than present CTs. Although various reconstructing methods have been proposed so far, the method practically employed at present is the filtered backprojection (FBP) method only, which can give high quality image reconstruction, but takes much computing time. In the past, the two-dimensional Fourier transform (TFT) method was regarded as unsuitable to practical use because the quality of images obtained was not good, in spite of the promising method for high speed reconstruction because of its less computing time. However, since it was revealed that the image quality by TFT method depended greatly on interpolation accuracy in two-dimensional Fourier space, the authors have developed a high-speed calculation algorithm that can obtain high quality images by pursuing the relationship between the image quality and the interpolation method. In this case, radial data sampling points in Fourier space are increased to β-th power of 2 times, and the linear or spline interpolation is used. Comparison of this method with the present FBP method resulted in the conclusion that the image quality is almost the same in practical image matrix, the computational time by TFT method becomes about 1/10 of FBP method, and the memory capacity also reduces by about 20 %. (Wakatsuki, Y.)

  1. Computerized industrial tomography

    International Nuclear Information System (INIS)

    Ashraf, M.M.

    1999-01-01

    Computerized Tomographic (CT) has been used for a number of applications in the field of medicine and industry. For the last couple of years, the technique has been applied for the material characterization and detection of defects and flaws inside the industrial components of nuclear, aerospace and missile industries. A CT scanner of first generation was developed at the institute. The scanner has been used to demonstrate couple of applications of CT in the field of non destructive testing of materials. The data acquired by placing the test objects at various angles and scanning the object through a source detector assembly has been processed on a Pentium computer for image reconstruction using a filtered back projection method. The technique has been developed which can be modified and improved to study various other applications in materials science and a modern computerized tomographic facility can be established. (author)

  2. Computerized tomography using high resolution X-ray imaging system with a microfocus source

    International Nuclear Information System (INIS)

    Zaprazny, Z.; Korytar, D.; Konopka, P.; Ac, V.; Bielecki, J.

    2011-01-01

    In recent years there is an effort to image an internal structure of an object by using not only conventional 2D X-ray radiography but also using high resolution 3D tomography which is based on reconstruction of multiple 2D projections at various angular positions of the object. We have previously reported [1] the development and basic parameters of a high resolution x-ray imaging system with a microfocus source. We report the recent progress using this high resolution X-ray laboratory system in this work. These first findings show that our system is particularly suitable for light weight and nonmetallic objects such as biological objects, plastics, wood, paper, etc. where phase contrast helps to increase the visibility of the finest structures of the object. Phase-contrast X-ray Computerized Tomography is of our special interest because it is an emerging imaging technique that can be implemented at third generation synchrotron radiation sources and also in laboratory conditions using a microfocus X-ray tube or beam conditioning optics. (authors)

  3. Computerized tomography of orbital lesions

    International Nuclear Information System (INIS)

    Kuroiwa, Mayumi

    1981-01-01

    Two different types of computerized tomography scanners (CT scanner), i.e. a whole-body CT scanner (GE-CT/T8800) and a cerebral CT scanner (EMI-1010), were compared in the assessment and diagnosis of various orbital lesions. The whole-body CT scanner was found to be advantageous over the cerebral CT scanner for the following reasons: (1) CT images were more informative due to thinner slices associated with smaller-sized and larger-numbered matrices; (2) less artifacts derived from motion of the head or eyeball were produced because of the shorter scanning time; (3) with a devised gantry, coronal dissections were available whenever demanded. (author)

  4. Accurately Diagnosing Uric Acid Stones from Conventional Computerized Tomography Imaging: Development and Preliminary Assessment of a Pixel Mapping Software.

    Science.gov (United States)

    Ganesan, Vishnu; De, Shubha; Shkumat, Nicholas; Marchini, Giovanni; Monga, Manoj

    2018-02-01

    Preoperative determination of uric acid stones from computerized tomography imaging would be of tremendous clinical use. We sought to design a software algorithm that could apply data from noncontrast computerized tomography to predict the presence of uric acid stones. Patients with pure uric acid and calcium oxalate stones were identified from our stone registry. Only stones greater than 4 mm which were clearly traceable from initial computerized tomography to final composition were included in analysis. A semiautomated computer algorithm was used to process image data. Average and maximum HU, eccentricity (deviation from a circle) and kurtosis (peakedness vs flatness) were automatically generated. These parameters were examined in several mathematical models to predict the presence of uric acid stones. A total of 100 patients, of whom 52 had calcium oxalate and 48 had uric acid stones, were included in the final analysis. Uric acid stones were significantly larger (12.2 vs 9.0 mm, p = 0.03) but calcium oxalate stones had higher mean attenuation (457 vs 315 HU, p = 0.001) and maximum attenuation (918 vs 553 HU, p uric acid stones. A combination of stone size, attenuation intensity and attenuation pattern from conventional computerized tomography can distinguish uric acid stones from calcium oxalate stones with high sensitivity and specificity. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  5. Computerized tomography in myotonic dystrophy

    International Nuclear Information System (INIS)

    Gellerich, I.; Mueller, D.; Koch, R.D.

    1986-01-01

    Besides clinical symptoms, progress and electromyography computerized tomography improves the diagnostics of myotonic dystrophy. Even small changes in muscular structure are detectable and especially the musculus soleus exhibits early and pronounced alterations. By means of density distribution pattern an improved characterization of the disease is possible. Additional information is obtained by cerebral computerized tomography. Atrophy of brain tissue is to be expected in all patients with myotonic dystrophy. (author)

  6. Computerized tomography in the diagnosis of hyperparathyroidism

    International Nuclear Information System (INIS)

    Sobota, J.; Girl, J.; Sotornik, I.; Kocandrle, V.

    1990-01-01

    Long-term experience in the application of computerized tomography to the diagnosis of hyperparathyroidism is summarized. Based on a large number of examinations (164) of parathyroid glands associated with the possibility of verification and comparison with the results of ultrasonography and other imaging methods, the potential of computerized tomography in the diagnosis of hyperparathyroidism and its advantages and limitations are summarized. It is concluded that owing to its high diagnostic precision, this technique can be regarded reliable in detecting enlarged parathyroid glands. (author). 11 figs., 1 tab., 19 refs

  7. Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

    Science.gov (United States)

    Guo, J.; Bücherl, T.; Zou, Y.; Guo, Z.

    2011-09-01

    Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

  8. Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

    International Nuclear Information System (INIS)

    Guo, J.; Buecherl, T.; Zou, Y.; Guo, Z.

    2011-01-01

    Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

  9. Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

    Energy Technology Data Exchange (ETDEWEB)

    Guo, J. [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China); Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, Garching 80748 (Germany); Buecherl, T. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, Garching 80748 (Germany); Zou, Y., E-mail: zouyubin@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China); Guo, Z. [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China)

    2011-09-21

    Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

  10. Renal calyceal anatomy characterization with 3-dimensional in vivo computerized tomography imaging.

    Science.gov (United States)

    Miller, Joe; Durack, Jeremy C; Sorensen, Mathew D; Wang, James H; Stoller, Marshall L

    2013-02-01

    Calyceal selection for percutaneous renal access is critical for safe, effective performance of percutaneous nephrolithotomy. Available anatomical evidence is contradictory and incomplete. We present detailed renal calyceal anatomy obtained from in vivo 3-dimentional computerized tomography renderings. A total of 60 computerized tomography urograms were randomly selected. The renal collecting system was isolated and 3-dimensional renderings were constructed. The primary plane of each calyceal group of 100 kidneys was determined. A coronal maximum intensity projection was used for simulated percutaneous access. The most inferior calyx was designated calyx 1. Moving superiorly, the subsequent calyces were designated calyx 2 and, when present, calyx 3. The surface rendering was rotated to assess the primary plane of the calyceal group and the orientation of the select calyx. The primary plane of the upper pole calyceal group was mediolateral in 95% of kidneys and the primary plane of the lower pole calyceal group was anteroposterior in 95%. Calyx 2 was chosen in 90 of 97 simulations and it was appropriate in 92%. Calyx 3 was chosen in 7 simulations but it was appropriate in only 57%. Calyx 1 was not selected in any simulation and it was anteriorly oriented in 75% of kidneys. Appropriate lower pole calyceal access can be reliably accomplished with an understanding of the anatomical relationship between individual calyceal orientation and the primary plane of the calyceal group. Calyx 2 is most often appropriate for accessing the anteroposterior primary plane of the lower pole. Calyx 1 is most commonly oriented anterior. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  11. Algorithmic fundamentals of computerized tomography and of transverse analogue tomography

    International Nuclear Information System (INIS)

    Heckmann, K.

    1981-01-01

    Computerized tomography and transverse analogue tomography are two different approaches to the same goal, namely, transverse tomography. The algorithm is discussed and compared. Transverse tomography appears capable of further development, judging by this comparison. (orig.) [de

  12. Radiographic analysis of body composition by computerized axial tomography

    International Nuclear Information System (INIS)

    Heymsfield, S.B.

    1986-01-01

    Radiographic methods of evaluating body composition have been applied for over five decades. A marked improvement in this approach occurred in the mid-nineteen-seventies with the introduction of computerized axial tomography. High image contrast, cross-sectional imaging and rapid computerized data processing make this technique a sophisticated clinically applicable tool. (author)

  13. Methods for processing and analysis functional and anatomical brain images: computerized tomography, emission tomography and nuclear resonance imaging

    International Nuclear Information System (INIS)

    Mazoyer, B.M.

    1988-01-01

    The various methods for brain image processing and analysis are presented and compared. The following topics are developed: the physical basis of brain image comparison (nature and formation of signals intrinsic performance of the methods image characteristics); mathematical methods for image processing and analysis (filtering, functional parameter extraction, morphological analysis, robotics and artificial intelligence); methods for anatomical localization (neuro-anatomy atlas, proportional stereotaxic atlas, numerized atlas); methodology of cerebral image superposition (normalization, retiming); image networks [fr

  14. Diagnostics of neuromuscular diseases with the aid of computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Visser, M de; Verbeeten, Jr, B J

    1988-06-04

    In this article the diagnosis of neuromuscular diseases with the aid of computerized tomography is treated. Computerized tomography of skeletal muscles give no information which is pathognomonic for particular diseases. But the technique can be used in the following aspects: to choose a muscle for a biopsy; when it is not possible to examine the function of a muscle, a CT scan can visualize morphological deviations; in the differentiation of muscle hypertrophy and pseudo-hypertrophy. For some cases as Becker-type muscular dystrophy, facioscapulohumeral dystrophy and Kugelberg-Welander type spinal muscular atrophy computerized tomography gives characteristic images. 10 refs.; 6 figs.

  15. Diagnostics of neuromuscular diseases with the aid of computerized tomography

    International Nuclear Information System (INIS)

    Visser, M. de; Verbeeten, B.J. Jr.

    1988-01-01

    In this article the diagnosis of neuromuscular diseases with the aid of computerized tomography is treated. Computerized tomography of skeletal muscles give no information which is pathognomonic for particular diseases. But the technique can be used in the following aspects: to choose a muscle for a biopsy; when it is not possible to examine the function of a muscle, a CT scan can visualize morphological deviations; in the differentiation of muscle hypertrophy and pseudo-hypertrophy. For some cases as Becker-type muscular dystrophy, facioscapulohumeral dystrophy and Kugelberg-Welander type spinal muscular atrophy computerized tomography gives characteristic images. 10 refs.; 6 figs

  16. Single photon emission computerized tomography (SPECT)

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as 123 I and 99 Tc m that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  17. Single photon emission computerized tomography (SPECT)

    Energy Technology Data Exchange (ETDEWEB)

    Ganatra, R D

    1993-12-31

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as {sup 123}I and {sup 99}Tc{sup m} that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  18. Patient surface doses in computerized tomography examinations

    International Nuclear Information System (INIS)

    Vekic, B; Kovacevic, S.; Ranogajec-Komor, M.; Duvnjak, N.; Marusic, P.; Anic, P.; Dolencic, P.

    1996-01-01

    The diagnostic value of computerized tomography has increased due to very rapid technical advances in both equipment and techniques. When the CT scanners were introduced, a significant problem for the specification of the radiation dose imparted to the patient undergoing CT examination has been created. In CT, the conditions of exposure are quite different from those in conventional X-ray imaging. CT procedure involves the continuous tomography of thin layers. Some of these layers touch each other while others overlap. The radiation doses received by patients can vary considerably. In addition to the radiation from the collimated primary beam, patients are exposed to significant scattered doses in unpredictable amounts. Every effort should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The aims of this work were to determine the surface doses delivered to various organs of patients during various computerized tomography examinations (head, thorax, kidney, abdomen and pelvis). Particular attention was directed to the precise determination of doses received by the eyes (during CT of head) and gonads (during CT of pelvis and lower abdomen) since these organs can be near or even in the primary X-ray beam

  19. Interfraction Prostate Rotation Determined from In-Room Computerized Tomography Images

    International Nuclear Information System (INIS)

    Owen, Rebecca; Kron, Tomas; Foroudi, Farshad; Milner, Alvin; Cox, Jennifer; Duchesne, Gillian

    2011-01-01

    Fiducial markers (FMs) are commonly used as a correction technique for interfraction translations of the prostate. The aim of this investigation was to determine the magnitude of prostate rotations using 2 methods: FM coordinates and the anatomical border of the prostate and rectum. Daily computed tomography (CT) scans (n = 346) of 10 prostate cancer patients with 3 implanted FMs were acquired using the CT on rails. FM coordinates were used to determine rotation in the sagittal, transverse, and coronal planes, and CT contours of the prostate and rectum were used to determine rotation along the sagittal plane. An adaptive technique based on a subset of images (n = 6; planning and first 5 treatment CTs) to reduce systematic rotation errors in the sagittal plane was tested. The standard deviation (SD) of systematic rotation from FM coordinates was 7.6 o , 7.7 o , and 5.0 o in the sagittal, transverse and coronal planes. The corresponding SD of random error was 10.2 o , 15.8 o , and 6.5 o . Errors in the sagittal plane, determined from prostate and rectal contours, were 10.1 o (systematic) and 7.7 o (random). These results did not correlate with rotation computed from FM coordinates (r = -0.017; p = 0.753, n = 337). The systematic error could be reduced by 43% to 5.6 o when the mean prostate position was estimated from 6 CT scans. Prostate rotation is a significant source of error that appears to be more accurately determined using the anatomical border of the prostate and rectum rather than FMs, thus highlighting the utility of CT image guidance.

  20. Brain metastasis of small cell lung carcinoma. Comparison of Gd-DTPA enhanced magnetic resonance imaging and enhanced computerized tomography

    International Nuclear Information System (INIS)

    Nomoto, Yasushi; Yamaguchi, Yutaka; Miyamoto, Tadaaki.

    1994-01-01

    Small cell carcinoma of the lung (SCLC) frequently metastasizes into the brain, resulting in serious influences upon prognosis. Delayed brain damage caused by prophylactic cranial irradiation (PCI) is also problematic. Gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI) was performed to detect early brain metastasis from SCLC, and its usefulness was compared with contrast computerized tomography (CT). Among 25 SCLC patients, brain metastasis was detected in 11 by MRI and in 10 by CT, although six of them were completely asymptomatic. In the 11 patients, 6.3 and 2.4 lesions were respectively detected on average by MRI and CT. The ability of MRI to detect metastatic lesions of ≥15 mm diameter did not differ from that of CT, but became different as lesions became smaller (P<0.002), and MRI had a decided advantage over CT because as many as 30 lesions of ≤5 mm diameter were detected by MRI, whereas such lesions visualized on CT numbered only one (P<0.0001). MRI was incomparably superior to CT (P<0.0004) for subtentorial lesions since 18 lesions were detected on MRI, but only three, measuring ≥25 mm in diameter, were demonstrated on CT. Gd-DTPA enhanced MRI was determined to be extremely useful in the early diagnosis of SCLC brain metastasis. MRI was thought to reduce delayed brain damage caused by PCI if performed according to an adequate schedule. (author)

  1. Single photon emission computerized tomography

    International Nuclear Information System (INIS)

    Hooge, P. de.

    1983-01-01

    In this thesis two single-photon emission tomographic techniques are presented: (a) longitudinal tomography with a rotating slanting-hole collimator, and (b) transversal tomography with a rotating gamma camera. These methods overcome the disadvantages of conventional scintigraphy. Both detection systems and the image construction methods are explained and comparisons with conventional scintigraphy are drawn. One chapter is dedicated to the determination of system parameters like spatial resolution, contrast, detector uniformity, and size of the object, by phantom studies. In separate chapters the results are presented of detection of tumors and metastases in the liver and the liver hilus; skeletal diseases; various pathological aberrations of the brain; and myocardial perfusion. The possible use of these two ect's for other organs and body areas is discussed in the last chapter. (Auth.)

  2. Soft tissue segmentation and 3D display from computerized tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Fan, R.T.; Trivedi, S.S.; Fellingham, L.L.; Gamboa-Aldeco, A.; Hedgcock, M.W.

    1987-01-01

    Volume calculation and 3D display of human anatomy facilitate a physician's diagnosis, treatment, and evaluation. Accurate segmentation of soft tissue structures is a prerequisite for such volume calculations and 3D displays, but segmentation by hand-outlining structures is often tedious and time-consuming. In this paper, methods based on analysis of statistics of image gray level are applied to segmentation of soft tissue in medical images, with the goal of making segmentation automatic or semi-automatic. The resulting segmented images, volume calculations, and 3D displays are analyzed and compared with results based on physician-drawn outlines as well as actual volume measurements

  3. Evaluation of brain scintigraphy and computerized tomography

    International Nuclear Information System (INIS)

    Cavailloles, F.; Dairou, R.; Desbleds, M.T.; Benoit, C.; Larmande, P.; Bok, B.; Alperovitch, A.

    1983-01-01

    In order to assess the clinical usefulness of brain computerized tomography and radionuclide scan, a prospective study was performed on a series of 554 patients. The detection rate was assessed as well as the identification rate of lesions. In addition, the usefulness of both tests was appreciated subjectively by two neurologists reviewing the patients' files. Both give reasonably similar results: computerized tomography is superior to radionuclide scan in the diagnosis of tumors and intracerebral hematomas, the radionuclide scan being slightly superior in the diagnosis of purely ischemic CVA and subdural hematomas. The superiority which was subjectively conceded to computerized tomography was greater than that objectively demonstrated. However, clinical usefulness of computerized tomography was judged important in only 50% of the cases. Moreover, to request both computerized tomography and radionuclide scan appeared as having no interest in 83% of the cases. In that series, the diagnostic hypotheses were in agreement with the final diagnosis in 88% of the cases. Bias encountered in this type of studies are discussed [fr

  4. Computerized tomography findings in nasolacrimal dysfunction

    International Nuclear Information System (INIS)

    Ishida, Toshio; Nakamura, Yasuhisa; Kumagai, Michiasa

    1985-01-01

    We examined 17 cases (22 lesions) with stenosis or obstruction in the lacrimal drainage system with the use of computerized tomography (CT). In idio pathic cases, the site of obstruction was located either in the upper nasolacrimal duct or at the junction of the lacrimal sac and the nasolacrimal duct. In post-traumatic cases, it was located in the lower nasolacrimal duct. The obstructed areas appeared as homogenous in CT image with CT values ranging between +60 and +80. These findings were suggestive of granulation tissue. The stenosed areas appeared, on the other hand, as areas of unequal density. Lacrimal passage appeared to be maintained through the low-density portion. The CT values of the lacrimal sac was around +40 in dacryocystitis and around +20 to +30 other cases. (author)

  5. Incomplete-data image reconstructions in industrial x-ray computerized tomography

    International Nuclear Information System (INIS)

    Tam, K.C.; Eberhard, J.W.; Mitchell, K.W.

    1989-01-01

    In earlier works it was concluded that image reconstruction from incomplete data can be achieved through an iterative transform algorithm which utilizes the a priori information on the object to compensate for the missing data. The image is transformed back and forth between the object space and the projection space, being corrected by the a priori information on the object in the object space, and by the known projections in the projection space. The a priori information in the object space includes a boundary enclosing the object, and an upper bound and a lower bound of the object density. In this paper we report the results of testing the iterative transform algorithm on experimental data. X-ray sinogram data of the cross section of a F404 high-pressure turbine blade made of Ni-based superalloy were supplied to us by the Aircraft Engine Business Group of General Electric Company at Cincinnati, Ohio. From the data set we simulated two kinds of incomplete data situations, incomplete projection and limited-angle scanning, and applied the iterative transform algorithm to reconstruct the images. The results validated the practical value of the iterative transform algorithm in reconstructing images from incomplete x-ray data, both incomplete projections and limited-angle data. In all the cases tested there were significant improvements in the appearance of the images after iterations. The visual improvements are substantiated in a quantitative manner by the plots of errors in wall thickness measurements which in general decrease in magnitude with iterations

  6. Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.

    Science.gov (United States)

    Gomes, Manuel; Aldridge, Robert W; Wylie, Peter; Bell, James; Epstein, Owen

    2013-04-01

    When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown. The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS. We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions. 3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained. 3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.

  7. Computerized tomography and morphological findings in brain infarcts and intracerebral haematonous for identical image planes

    Energy Technology Data Exchange (ETDEWEB)

    Clar, H E; Bock, W J; Hahse, H C; Gerhard, L; Flossdorf, R [Essen Univ. (Gesamthochschule) (Germany, F.R.). Neurochirurgische Klinik; Duesseldorf Univ. (Germany, F.R.). Neurochirurgische Klinik; Essen Univ. (Gesamthochschule) (Germany, F.R.). Roentgendiagnostisches Zentralinstitut; Essen Univ. (Gesamthochschule) (Germany, F.R.). Neuropathologisches Inst.)

    1979-01-01

    Contrary to earlier, more optimistic publications, CT findings do not always agree with brain sections of the same image plane. For example, in spite of a clinically proved infrarot anamnesis, Huber was unable to detect a pathological CT finding in 20% of the cases. Still, CT is the method that yields the best information on cerebral ischaemios, haemorrhaegic infarcts, and haemorrhagies if purposefully applied.

  8. Computerized tomography in orthopaedics and traumatology

    International Nuclear Information System (INIS)

    Boettger, E.; Heckl, R.; Rehabilitations-Krankenhaus Langensteinbach, Karlsbad

    1981-01-01

    Computerized tomography in traumatology is the selected method for the indications mentioned, so that angiographic investigations are only necessary in exceptional cases. Computerized tomography is also better than other methods when diagnozing soft part tumours, however, angiography is still indicated preoperatively for individual cases. CT is only good as additional help to conventional diagnostics with bone tumours. The differential diagnosis cysts-tumour is possible using contrast medium injections. The frequently large soft part share of tumours is recognizable with osteolytic tumours so that a better irradiation and operation planning can be effected. Diseases in the spinal canal can only be assessed with reservation using modern equipment. Lumbar dislocations of the disk can mostly not be sufficiently determined. Perivertebral abscesses can be certainly detected using computerized tomography. This is particularly so for abscesses prior to calcification. (orig.) [de

  9. Direct image reconstruction with limited angle projection data for computerized tomography

    International Nuclear Information System (INIS)

    Inouye, T.

    1980-01-01

    Discussions are made on the minimum angle range for projection data necessary to reconstruct the complete CT image. As is easily shown from the image reconstruction theorem, the lack of projection angle provides no data for the Fourier transformed function of the object on the corresponding angular directions, where the projections are missing. In a normal situation, the Fourier transformed function of an object image holds an analytic characteristic with respect to two-dimensional orthogonal parameters. This characteristic enables uniquely prolonging the function outside the obtained region employing a sort of analytic continuation with respect to both parameters. In the method reported here, an object pattern, which is confined within a finite range, is shifted to a specified region to have complete orthogonal function expansions without changing the projection angle directions. These orthogonal functions are analytically extended to the missing projection angle range and the whole function is determined. This method does not include any estimation process, whose effectiveness is often seriously jeopardized by the presence of a slight fluctuation component. Computer simulations were carried out to demonstrate the effectiveness of the method

  10. Measurement and analysis of noise power spectrum of computerized tomography in images

    International Nuclear Information System (INIS)

    Castro Tejero, P.; Garayoa Roca, J.

    2013-01-01

    This paper examines the implementation of the spectrum of powers of the noise, NPS, as metric to characterize the noise, both in magnitude and in texture, for CT scans. The NPS found show that you for convolution filters that assume a greater softening in the reconstructed image, spectrum is concentrated in the low frequencies, while for filters sharp, the spectrum extends to high frequencies. In the analyzed cases, there is a low frequency component, largely due to the structure-borne noise, which can be a potential negative effect on the detectability of injuries. (Author)

  11. The limited angle problem in computerized tomography

    International Nuclear Information System (INIS)

    Louis, A.K.

    1984-01-01

    Fast reconstruction formulae in X-ray computerized tomography demand the directions, in which the measurements are taken, to be equally distributed over the whole circle. In many applications data can only be provided in a restricted range. Here the intrinsic difficulties are studied by giving a singular value decomposition of the Radon transform in a restricted range. Practical limitations are deduced. (orig.)

  12. Is hybridic positron emission tomography/computerized tomography the only option? The future of nuclear medicine and molecular imaging.

    Science.gov (United States)

    Grammaticos, Philip; Zerva, Cherry; Asteriadis, Ioannis; Trontzos, Christos; Hatziioannou, Kostas

    2007-01-01

    sources of radiation" b) nuclear radiation and c) molecular nuclear medicine. The "European Journal of Nuclear Medicine and Molecular Imaging" shall have to erase the three last words of its title and be renamed. As Professor Abass Alavi et al (2007), have mentioned: "Is PET/CT the only option?" In favor of PET/CT are the following: Attenuation correction (AC) and better anatomical localization of lesions visualized with PET. Also PET/CT can be used as a diagnostic CT scanner (dCT). Against using the PET/CT scanners are the following arguments: a) This equipment is not necessary because we can always ask the Radiologists for a dCT scan. Many patients have already done a dCT scan at the time they are referred for a PET scan to the Nuclear Medicine Department. b) The absolute clinical indications for PET/CT with the use of a contrast agent, are under investigation. c) Although there is at present a list of indications suggested for the PET/CT scanner, there are studies disputing some of these indications, as for example in metastatic colon cancer where a high diagnostic accuracy for PET study alone, has been reported. d) The option of AC performed by the PET/CT scanner has also been questioned. Artifacts may be up to 84%. e) The PET/CT is expensive, time consuming, space occupying, and needs additional medical and technical personnel. f) Not to mention the extra radiation dose to the patients. g) Shall we inform those young medical students who wish to become nuclear medicine physicians, to hold their decision till the content of future Nuclear Medicine is clarified? We may suggest that: Our specialty could be renamed as: "Clinical Nuclear Medicine" and include additional "proper certified education" on the PET/CT equipment. The PET/CT scanner should remain in the Nuclear Medicine Department where Radiologists could act as advisors.

  13. Study on forefoot by computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Machida, Eiichi (Nihon Univ., Tokyo. School of Medicine)

    1983-10-01

    Computerized tomography (CT) was used to study coronary sections of the forefoot in both normal and abnormal human feet. CT images of the transverse arches at the metatarsal head, middle and base of the shaft were classified into five patterns. In the pattern most commonly found in normal feet, the second metatarsus appeared elevated above the other metatarsal bones at all points, and there was a gradual and even reduction in elevation from the second to the fifth metatarsal. In cases of hallux valgus, however, a variety of deformities were noted in the arc of the second to fifth metatarsals, particularly at the head. The rotation of the first metatarsus and shift of the sesamoids were measured from CT images at the head of the first metatarsus. In hallux valgus, both the rotation and the sesamoid shift appeared to have a wider angle than in the case of normal feet. In normal feet, the differences between the rotation of the first metatarsus and shift of the sesamoids were relatively small, whereas in hallux valgus there was a much greater degree of variation. Furthermore, while normal feet the variation in rotation of the first metatarsus and sesamoid shift both tended to be either great or small, in hallux valgus a large degree of sesamoid shift was sometimes found in combination with a small degree of rotation of the first metatarsus.

  14. Study on forefoot by computerized tomography

    International Nuclear Information System (INIS)

    Machida, Eiichi

    1983-01-01

    Computerized tomography (CT) was used to study coronary sections of the forefoot in both normal and abnormal human feet. CT images of the transverse arches at the metatarsal head, middle and base of the shaft were classified into five patterns. In the pattern most commonly found in normal feet, the second metatarsus appeared elevated above the other metatarsal bones at all points, and there was a gradual and even reduction in elevation from the second to the fifth metatarsal. In cases of hallux valgus, however, a variety of deformities were noted in the arc of the second to fifth metatarsals, particularly at the head. The rotation of the first metatarsus and shift of the sesamoids were measured from CT images at the head of the first metatarsus. In hallux valgus, both the rotation and the sesamoid shift appeared to have a wider angle than in the case of normal feet. In normal feet, the differences between the rotation of the first metatarsus and shift of the sesamoids were relatively small, whereas in hallux valgus there was a much greater degree of variation. Furthermore, while normal feet the variation in rotation of the first metatarsus and sesamoid shift both tended to be either great or small, in hallux valgus a large degree of sesamoid shift was sometimes found in combination with a small degree of rotatin of the first metatarsus. (author)

  15. Quality criteria for abdominal computerized tomography

    International Nuclear Information System (INIS)

    Huebener, K.H.; Kurtz, B.; Metzger, H.O.F.

    1985-01-01

    Quality, not only in obdominal computerized tomography, is determined by the measurable technical parameters and, to an important extent, also bei individual factors, among which the diagnostic skill and experience of the examiner is one of the most decisive. These individual factors and the part they play with regard to the quality of CT-assisted diagnosis may well equal the technical parameters, as they significantly influence the course of examinations, resulting indications for contrast medium application, and the sensitivity of the diagnosis. The authors are convinced that especially for abdominal CT, standardized examination techniques inevitably would bring down the diagnostic quality. The technical parameters are of equal significance to achieving the diagnostic optimum, and to these parameters one has to count equipment characteristics as well as the data given by the examiner. Exposure time, spatial resolution and density differentiation are given by the equipment specifications but have to be adapted to and optimised to the clinical problems involved in every case. Another important task is that of routine imaging of given anatomic structures, for adequate evaluation of individual conditions. (orig./MG) [de

  16. Computerized tomography in atypical Pott's disease

    International Nuclear Information System (INIS)

    Cabrera, M.N.B.; Wang, E.H.M.

    1993-01-01

    Classical Pott's disease is described as a two-vertebrae disease with the destruction of the intervening invertebral disc. Computerized tomography has been used in the differential diagnosis of spine infections and neoplasms. We reviewed CT scans of patients seen at the Philippine General Hospital over a two-year period with atypical presentations of atypical tuberculous spondylitis. We used the computerized tomography findings described as characteristic of classical Pott's disease as criteria in evaluating the CT scans of patients diagnosed to have Atypical Pott's Disease. Although the number of patients prevented sensitivity and specificity studies to be done, our results strongly suggest that the same CT criteria used to diagnose Classical Pott's Disease may also be used to diagnose Pott's disease in its atypical form. (Author.). 13 refs

  17. 10 years of computerized tomography reviewed

    International Nuclear Information System (INIS)

    Duemmling, K.

    1984-01-01

    The history and some highlights of computerized tomography are reviewed. The various technologies employed in the course of CT development are described along with the limitations that led to their disappearance. The problems still to be solved in medicine, the increasing influence of nuclear magnetic resonance, and some scientific aspects have opened up new lines of development which are briefly mentioned. (orig./WU) [de

  18. Computerized tomography of gall bladder cancer

    International Nuclear Information System (INIS)

    Todua, F.I.; Karmazanovskij, G.G.

    1989-01-01

    The authors have summed up the experience in the use of computerized tomography (CT) in diagnosis of gall bladder cancer. The investigation of 17 patients with cancer of this site showed a high informative value of the method. A retrospective comparative study of the results of CT and surgical interventions was carried out. It has been concluded that CT makes it possible not only to diagnose malignant lesions of the bile ducts but also to assess a possible scope of a forthcoming operation

  19. Increased intracranial pressure: evaluation by computerized tomography

    International Nuclear Information System (INIS)

    Lightfoote, W.E.; Pressman, B.D.

    1975-01-01

    Computerized tomography is clearly very useful in the evaluation of patients with increased intracranial pressure and suspected pseudotumor cerebri. It provides an index of ventricular size and configuration and has the capability of demonstrating intracranial lesions. Moreover, this new technique is rapid and non-invasive, and is without attendant risks. Examinations may be performed serially as the clinical process evolves, thereby giving roentgenographic correlation to the clinical features. (U.S.)

  20. Computerized tomography of the mandibular joints and masticatory muscles

    International Nuclear Information System (INIS)

    Huels, A.B.

    1981-01-01

    A methodology for computerized tomography of the mandibular joints was developed and applied in 80 test persons. Imaging of the mandibular joints is possible with a tomographic technique with 5 mm-overlap, full utilisation of the enlargement capacity of the imaging device, and combined use of transversal and coronary tomography. The method yields full latero-medial, cranio-caudal and anterior-posterior views of the condyle and fossa contours, free of interferences and of distortions caused by the projection. Positional diagnoses are thus possible as well as diagnoses of pathological structural changes. (orig./MG) [de

  1. Computerized tomography in radiodiagnosis of pneumonia

    International Nuclear Information System (INIS)

    Degtyareva, I.A.; Mamaev, V.V.; Savchenko, A.P.

    1989-01-01

    Experience in the use of computerized tomography (CT) in combined radiodiagnosis of pneumonia was analysed. It has been concluded that CT objectively reflects morphological inflammatory changes and permits their all-round assessment over time. The diagnosis of pneumonia in CT is based on classical x-ray symptoms. As compared to survery radiography CT reveals symptoms of pneumonia to the full at earlier stages. CT is an important additional method of investigation of inflammatory pulmonary diseases but it should not be used separately without survey radiography. In a majority of cases when CT is performed there is no need in x-ray tomography

  2. Staging of bronchogenic carcinoma by computerized tomography

    International Nuclear Information System (INIS)

    Sommer, B.; Bauer, W.M.; Rath, M.; Fenzl, G.; Stelter, W.J.; Lissner, J.

    1981-01-01

    It was possible to check the information obtained by CT scanning in 36 patients out of 49 who had been subjected to computerized tomography, in respect of the extension of the primary tumour (T stage), and in 25 patients in respect of the degree of mediastinal lymphatic node involvement (N stage). In all 49 patients, the presence of bronchogenic carcinoma had been safely established. In 97% of the cases, assessment of the extension of the primary tumour was found to be correct. Assessment of the N stage, however, is more problematic, since detection of mediastinal lymphatic nodes by computerized tomography does not necessarily tell us something about their metastatic involvement. If all recognizable lymphatic nodes are interpreted as potential metastases, we have no false negative but 61% false positive results because of the frequency of postinflammatory or anthracotic lymphatic nodes. In case of exclusive assessment of lymphatic node enlargement above 1 cm diameter, the rate of metastatic nodes increases considerably (83%). Computerized tomography is definitely superior to all roentgenological methods in assessing the stage of a bronchogenic carcinoma; hence, it could occupy a key position in determining the diagnostic and therapeutic approach in patients with this disease. (orig.) [de

  3. Case of neurosarcoidosis monitored by computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, T; Kimura, M; Komai, T; Yamamoto, S; Yamamura, I [Kanazawa Univ. (Japan). School of Medicine

    1979-12-01

    A 21-year-old man complaining of impaired visual acuity was admitted to the hospital. Physical examinations showed asymptomatic bilateral hilar lymphadenopathy and cardiomyopathy. Neurological findings disclosed left blindness and right temporal hemianopsia. Computerized tomography, pneumoencephalography and carotid angiography revealed a suprasellar mass. After the admission, the following symptoms deteriorated rapidly: diabetes insipidus, anterior pituitary dysfunction, visual loss of the right eye and hepatomegaly, subsequently consciousness disorder developed during a month though he was given steroids. The more deteriorated the clinical course, the larger the suprasellar mass with expanding hydrocephalus in repeated computerized tomographies. After the ventriculo-peritoneal shunt operation, consciousness improved. Diabetes insipidus also improved after Diabenese administration. On the operation, adhesive arachnoiditis over all the frontotemporal cortex and swollen purplishly red optic chiasm were exposed. Microscopically the specimen from the optic chiasm evidenced a sarcoid granuloma which composed of epitheroid cells, lymphocytes and multi-nucleated giant cells with numerous hemosiderin droplets. The specimen from the surface of the left frontal lobe showed thick fibrosis in the subarachnoid space. By steroids therapy, diabetes insipidus and hepatomegaly disappeared five months after the admission, whereas blindness never recovered. He died of developed status epilepticus eleven months after the admission. The authors reviewed neuroradiological findings of neurocarcoidosis based on pathological findings in the literature, and emphasized that computerized tomography was the most useful for diagnosis and treatment of neurosarcoidosis.

  4. Computerized tomography of the pancreas

    International Nuclear Information System (INIS)

    Dondelinger, R.; Campos, R.O.; Lamarque, J.L.

    1979-01-01

    Pancreatic anatomy is briefly reviewed. Tomographic images from normal pancreas and from pathological states (different kinds of pancreatitis; pancreatic tumors) of this organ are discussed. (M.A.) [pt

  5. Computerized tomography of intracranial tumors

    International Nuclear Information System (INIS)

    Hungenberg, T.

    1982-01-01

    The author discusses the possibilities and limits of CT in the differential diagnosis of intracranial tumours. His discussion is based on a quantitative classification and a number of case studies selected under the following aspects: Misinterpretation of the CT image; specific diagnostic problems; uncommon CT image of the tumour; rare histological findings. 118 patients were examined between November 1976 and April 1979. (orig./MG) [de

  6. Computerized tomography using fast neutrons

    International Nuclear Information System (INIS)

    Maier-Schuler, P.

    1992-03-01

    The equipment is transportable and can be used at different neutron sources. CT-images are presented showing that it is possible to get good results by using CT with fast neutrons in non destructive testing. Small defects with high contrasts can be detected as well as larger defects with small differences in material density. Since the neutrons interact with the nuclei and not with the electron density the CT-images contain different information compared with X-ray or γ images. As neutron sources always emit γ-radiation too, this radiation can be detected simultaneously with the neutrons. Therefore one can get a γ CT-image along with the neutron image. For the examination of small samples or objects containing materials with great differences in the linear attenuation coefficients like Al and H 2 thermal neutrons have been used for CT-measurements too. A spatial resolution and a density resolution of 0.1 mm and about 5% respectively could be achieved in the CT-images with fast neutrons and 0.04 mm with thermal neutrons. (orig./HP) [de

  7. Computerized tomography of cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, K; Mihara, T; Kobayashi, E; Yamamoto, K; Kusumoto, K [Kagoshima Univ. (Japan). Faculty of Medicine

    1978-12-01

    In 120 cases of patients with cerebral infarction, the affected areas in the CT images were analyzed with special reference to the site, the size, and the extension. Moreover, on 39 scans of 34 cases examined with 8 weeks after the onset of strokes, the CT images were analyzed from the viewpoint of the presence of a mass effect, edema, contrast enhancement, and the accompanying hemorrhage. From these investigations, the authors have obtained the following results; 1) The greatest incidence of infarcts was in the area supplied by the middle cerebral artery (57% of the cases), and, among those, the area of the lenticulostriate arteries showed the highest incidence (53%). Even in the posterior fossa, infarcts were found in 6% of the cases. These findings are coincident with those in autopsied cases. 2) Putaminal infarcts and infarctions occurring in the area supplied by the calcarine artery seemed to be uniformity of the arcuate pattern. 3) Most of the infarcts in the perfusion area of the anterior cerebral artery and the basal ganglia were found to be small and multifocal; they were thought to correspond with water-shed and/or lacunar infarcts. 4) In approximately 25% of the cases examined within 8 weeks after the onset of strokes, the CT images revealed mass effects which had never been observed after more than 3 weeks. In conclusion, the presence of a mass effect, accompanying hemorrhage, and contrast enhancement detected by CT should lead us to reconsider the conventional management of cerebral infarction.

  8. Direct coronary and sagittal computerized tomography of the pelvis

    International Nuclear Information System (INIS)

    Maier, W.; Bargon, G.

    1981-01-01

    Whereas quite a number of reports have been published on direct coronary and sagittal computed tomography of the cranium, no extensive experience has been collected on multidimensional computerized tomography of the pelvis. In this article, the authors report on their preliminary experiences in direct approximately sagittal and coronary computerized tomography of the pelvis in a group of 76 patients. (orig.) [de

  9. Paperback atlas of anatomical sectional images: Computerized tomography and NMR imaging. Vol. 1. Head, neck, vertebral column, joints

    International Nuclear Information System (INIS)

    Moeller, T.B.; Reif, E.

    1993-01-01

    Using the nomenclature relating to X-ray findings, the paperback atlas provides a concise, yet accurate description of fine anatomical structures visualized by sectional imaging procedures. Each of the approx. 250 sample images shown for the regions of the head (including neurocranium), vertebral column, neck, thorax, abdomen and muscosceletal system (including joints) is supplemented with a drawing that permits an immediate identification of any structure of interest. (orig.) [de

  10. Geometrical efficiency in computerized tomography: generalized model

    International Nuclear Information System (INIS)

    Costa, P.R.; Robilotta, C.C.

    1992-01-01

    A simplified model for producing sensitivity and exposure profiles in computerized tomographic system was recently developed allowing the forecast of profiles behaviour in the rotation center of the system. The generalization of this model for some point of the image plane was described, and the geometrical efficiency could be evaluated. (C.G.C.)

  11. Computerized tomography in diffuse diseases of the liver. Pt. 2

    International Nuclear Information System (INIS)

    Helmberger, H.; Vogel, U.; Bautz, W.

    1993-01-01

    Computerized tomography is a first-line method of imaging to confirm diffuse disorders of the liver suggested by preliminary clinical and biochemical findings. If the disease is caused by an obstructed vessel, this is reliably detected. For most types of thesaurismosis as well as hepatic steatosis and cirrhosis of the liver approaches to quantitative determinations of the spread of disease have been described in theory but so far failed to show great merits in practice. The transition from hepatic fibrosis to cirrhosis as the final developmental stage common to all those disorders has typical features on computerized tomography. This explains why the use of this method in diffuse hepatic disease offers particular advantages as regards the detection of complications occurring at an advanced stage ot the diagnosis of changes developing into malignancies. (orig.) [de

  12. Diagnostic medical imaging systems. X-ray radiography and angiography, computerized tomography, nuclear medicine, NMR imaging, sonography, integrated image information systems. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Morneburg, H.

    1995-01-01

    This third edition is based on major review and updating work. Many recent developments have been included, as for instance novel systems for fluoroscopy and mammography, spiral CT and electron beam CT, nuclear medical tomography ( SPECT and PET), novel techniques for fast NMR imaging, spectral and colour coded duplex sonography, as well as a new chapter on integrated image information systems, including network installations. (orig.) [de

  13. Computerized abdominal tomography in Wilson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchikura, Keiko; Ogawa, Teruyuki; Nakajima, Akihisa; Ono, Yasuhiko

    1986-05-01

    Cranial and abdominal computerized tomography (CT) was performed in a 10-year-old boy with Wilson's disease complicated by liver cirrhosis. Abdominal CT showed diffuse high density areas over the whole part of the liver propably due to copper sediments, although there was no abnormal cranial CT findings. Decreased high density area of the liver was seen 60 days after the administration of D-penicillamine, suggesting the excretion of copper from the liver. Abdominal CT, as well as cranial CT, may be of help to diagnose Wilson's disease and evaluate therapeutic effects. (Namekawa, K.).

  14. Influence of ASIR (Adaptative Statistical Iterative Reconstruction) variation in the image noise of computerized tomography for high voltage

    International Nuclear Information System (INIS)

    Mendes, L.M.M.; Pereira, W.B.R.; Vieira, J.G.; Lamounier, C.S.; Gonçalves, D.A.; Carvalho, G.N.P.; Santana, P.C.; Oliveira, P.M.C.; Reis, L.P.

    2017-01-01

    Computed tomography had great advances in the equipment used in the diagnostic practice, directly influencing the levels of radiation for the patient. It is essential to optimize techniques that must be employed to comply with the ALARA (As Low As Reasonably Achievable) principle of radioprotection. The relationship of ASIR (Adaptive Statistical Iterative Reconstruction) with image noise was studied. Central images of a homogeneous water simulator were obtained in a 20 mm scan using a 64-channel Lightspeed VCT tomograph of General Electric in helical acquisitions with a rotation time of 0.5 seconds, Pitch 0.984: 1, and thickness of cut 0.625 mm. All these constant parameters varying the voltage in two distinct values: 120 and 140 kV with use of the automatic current by the CAE (Automatic Exposure Control), ranging from 50 to 675 mA (120 kV) and from 50 to 610 mA (140kV), minimum and maximum values, respectively allowed for each voltage. Image noise was determined through ImageJ free software. The analysis of the obtained data compared the percentage variation of the noise in the image based on the ASIR value of 10%, concluding that there is a variation of approximately 50% when compared to the values of ASIR (100%) in both tensions. Dose evaluation is required in future studies to better utilize the relationship between dose and image quality

  15. Role of computerized tomography in diagnosis of atypical gall bladder and common bile duct stones

    International Nuclear Information System (INIS)

    El-Husseni, Tareq K.; Al-Shebrein, Ibrahim A.

    2001-01-01

    Objective was to assess the value of computerized tomography as an adjuvant to ultrasound in the diagnosis of atypical gallbladder and common duct stone disease. Real time ultrasound scanning for the gallbladder and common duct was performed in the routine manner. High resolution computerized tomography images were subsequently obtained for the region of interest. Computerized tomography resolved undetermined results as follows: 1. Non shadowing gallbladder debris (6 points), 2. Focal gallbladder wall thickening (2 points), 3. Stone obscured by calcified gallbladder wall (3 points), 4. Non visualized gallbladder double arc shadow (4 points), 5 and 6. Impacted gallbladder neck and common duct stones (18 points), computerized tomography gave false positive diagnosis in (2 points). Computerized tomography provided an effective and reliable means for the diagnosis of atypical gallbladder calculi when ultrasound was imprecise or the findings contradicted the clinical presentation. Finally if gallbladder neck or common duct stones are suspected, in addition to computerized tomography other imaging techniques such as magnetic resonance cholangio pancreatography or endoscopic retrograde cholangiopancreatography in addition to computerized tomography may be needed to avoid false positive diagnosis prior to surgery. (author)

  16. Computerized tomography in evaluation of the pulmonary hilum

    International Nuclear Information System (INIS)

    Secaf, M.; Ferreira, J.L.N.; Secaf, E.

    1987-01-01

    The use of computerized tomography as a method for evaluating the pulmonary hilum and its application in the diagnosis of endobronchial lesions, hilar masss, contiguous involvement of the mediastinum by hilar mass, and vascular hilar lesions are discussed. A comparative evaluation between conventional tomograms and computerized tomography is presented. (M.A.C.) [pt

  17. Patient radiation exposure in computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, V [Meditsinska Akademiya, Sofia (Bulgaria)

    1980-01-01

    Radiation exposure to patients undergoing axial computerized tomography as a tool of neurological X-ray diagnostics was studied. Doses thereby delivered were compared with those from routine head films at X-ray tube parameters 200 W, 70 kV, and 70 cm target-to-patient distance. Radiation exposures were analyzed with a view to improving shielding and procedural techniques. Comparisons were made using LiF TLD measurements with an Alderson phantom (standard for axial computer tomography). Skin and intracranial space doses were compared using two computers, Siretom I and Siretom 2000, for various positionings: frontal, fronto-lateral, temporal, temporo-occipital, and occipital. In addition, patient body doses with or without shielding and doses to subjects attending sick children or restless adults were examined. Achievable protection was estimated for lead shields of 0.5 mm lead equivalent. It was concluded that radiation doses delivered to neurologic patients undergoing axial computer tomography are smaller than those resulting from conventional X-ray examinations.

  18. Evaluation of standard and use tendency of image diagnosis exams in Brazil with emphasis in pediatric computerized tomography

    International Nuclear Information System (INIS)

    Dovales, Ana Cristina Murta

    2016-01-01

    There is little information on developing countries about the use of diagnostic imaging procedures and the doses associated with radiological examinations. This study assessed the pattern and trend of diagnostic imaging usage in outpatients of the Brazilian Unified Health System (SUS) by modality and examined body part. Emphasis was given to computed tomography (CT) scans for which the analysis was extended to the private health care sector and included the evaluation of age at examination distribution, and dose estimation for children and young adults. Information on the use of diagnostic imaging procedures among SUS outpatients was obtained from the Outpatient Information System (SIA) of the Department of Information Technology of SUS (DATASUS). Data on the use of CT in the private health care sector were extracted from the Radiological Information Systems (RIS) of 25 private radiology services in 8 Brazilian cities. Effective doses and absorbed doses on organs of interest were estimated individually for 4,497 patients younger than 20 years of age using CT scan technical parameters and Monte Carlo simulations of radiation transport. Between 2002 and 2012 it was observed that conventional radiology was the most frequent modality of diagnostic imaging in SUS outpatients, but more sophisticated modalities, such as CT and magnetic resonance imaging, had the highest growth rates over the study period. The most frequent CT scan in SUS outpatients between 2001 and 2011 was the head/neck exam, but abdomen/pelvis examinations were the ones that grew the most. Patients up to 20 years of age made approximately 13% and 9% of the CT examinations between 2008 and 2014 in the public and private health care systems, respectively. About one-third of the private-sector patients had more than one CT scan in this period. There was great variation in doses, even for the same type of procedure in patients of the same age group. The highest mean effective dose was 13.5 mSv estimated

  19. Organ doses from computerized tomography examinations

    Energy Technology Data Exchange (ETDEWEB)

    Janeczek, J.

    1995-12-31

    Estimates of mean organs doses from five typical computerized tomography (CT) examinations were obtained. Measurements were done using Rando-Alderson anthropomorphic phantom and thermoluminescent dosemeters (TLD). Radiation dose distributions within a phantom has been measured for each examination and results were used for organ dose calculation. Doses to organs specified by ICPR 60 Recommendations were measured for five CT scanners (CT/T8800, CT 9800, CT MAX - made by General Electric; CT 1200 SX - made by Picker; SOMATOM 2 - made by Siemens). Dose distributions from scattered radiation were measured and indicate that scattered radiation dose to thyroid and eye lens can be reduced by proper examination limits setting. The lowest mean organ doses were obtained from CT/T8800 scanner. More advanced scanners using high intensity continuous radiation were giving higher organ doses. (author). 23 refs, 6 figs, 13 tabs.

  20. Computerized axial tomography in traumatic cervical lesions

    International Nuclear Information System (INIS)

    Koyama, Tsunemaro

    1982-01-01

    Although plain computerized axial tomography cannot routinely demonstrate the spinal cord, it does provide excellent visualization of the bony outline of the spinal canal and vertebral column. So it should be reasonable to use this technique in cases of cervical traumatic disorders. In this paper we presented 10 cases of cervical traumatic lesions; 3 atlanto-axial dislocation, 2 cervical canal stenosis, 3 OPLL, 1 intramedullary hematoma and 1 C 2 -neurinoma. In some patients neurologic deficits were induced by cervical trauma. Bony lesions appeared more adequately deliniated than intraspinal lesions, however, in some cases intramedullary changes could also be demonstrated. The use of metrizamide with high resolution CT-scanner could improve the usefullness of this technique. (author)

  1. Organ doses from computerized tomography examinations

    International Nuclear Information System (INIS)

    Janeczek, J.

    1995-01-01

    Estimates of mean organs doses from five typical computerized tomography (CT) examinations were obtained. Measurements were done using Rando-Alderson anthropomorphic phantom and thermoluminescent dosemeters (TLD). Radiation dose distributions within a phantom has been measured for each examination and results were used for organ dose calculation. Doses to organs specified by ICPR 60 Recommendations were measured for five CT scanners (CT/T8800, CT 9800, CT MAX - made by General Electric; CT 1200 SX - made by Picker; SOMATOM 2 - made by Siemens). Dose distributions from scattered radiation were measured and indicate that scattered radiation dose to thyroid and eye lens can be reduced by proper examination limits setting. The lowest mean organ doses were obtained from CT/T8800 scanner. More advanced scanners using high intensity continuous radiation were giving higher organ doses. (author). 23 refs, 6 figs, 13 tabs

  2. Dose evaluation in diagnostic for computerized tomography

    International Nuclear Information System (INIS)

    Flores, W.; Borges, J.C.; Mota, H.

    1998-01-01

    The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

  3. Normal anatomical measurements in cervical computerized tomography

    International Nuclear Information System (INIS)

    Zaunbauer, W.; Daepp, S.; Haertel, M.

    1985-01-01

    Radiodiagnostically relevant normal values and variations for measurements of the cervical region, the arithmetical average and the standard deviation were determined from adequate computer tomograms on 60 healthy women and men, aged 20 to 83 years. The sagittal diameter of the prevertebral soft tissue and the lumina of the upper respiratory tract were evaluated at exactly defined levels between the hyoid bone and the incisura jugularis sterni. - The thickness of the aryepiglottic folds, the maximal sagittal and transverse diameters of the thyroid gland and the calibre of the great cervical vessels were defined. - To assess information about laryngeal function in computerized tomography, measurements of distances between the cervical spine and anatomical fixed points of the larynx and hypopharynx were made as well as of the degree of vocal cord movement during normal respiration and phonation. (orig.) [de

  4. Development and prospects of X-ray computerized tomography. I

    International Nuclear Information System (INIS)

    Dobes, V.

    1985-01-01

    The history and developmental trends are described of X-ray computerized tomography (CT) as are its applications in clinical practise. Suitable criteria and economic aspects are proposed for the choice of CT systems. The types are listed and described of X-ray CT systems, including brain, whole-body, mobile and special systems. A table is given showing available specifications (types of detectors, X-ray source, resolution, configuration, scan angles, scan fields, image reconstruction, etc.) for machines by different companies. (M.D.)

  5. Results of CT brain examinations in cerebrovascular emergency. [computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pinta, Z; Dolansky, J; Sorfova, J; Jerie, T

    1987-07-01

    Experience is briefly reported with CT (computerized tomography) diagnosis of cerebrovascular emergencies. It is pointed out that the introduction of computerized tomography greatly improved and made more accurate the diagnosis of focal ischemias and revealed significant differences in the foci of ischemia in hypertension patients and atherosclerosis patients without hypertension, and showed a higher incidence of intracerebral and subarachnoidal hemorrhages than previously thought. It is believed that knowledge gained thanks to CT (computerized tomography) will be of benefit to the primary and secondary prevention of cerebrovascular ischemias. (L.O.). 1 fig., 5 refs.

  6. The industrial computerized tomography applied to the rock analysis

    International Nuclear Information System (INIS)

    Tetzner, Guaraciaba de Campos

    2008-01-01

    This work is a study of the possibilities of the technical applications of Computerized Tomography (CT) by using a device developed in the Radiation Technology Center (CTR), Institute for Energy and Nuclear Research (IPEN-CNEN/SP). The equipment consists of a gamma radiation source ( 60 Co), a scintillation detector of sodium iodide doped with thallium (NaI (Tl)), a mechanical system to move the object (rotation and translation) and a computer system. This operating system has been designed and developed by the CTR-IPEN-CNEN/SP team using national resources and technology. The first validation test of the equipment was carried out using a cylindrical sample of polypropylene (phantom) with two cylindrical cavities (holes) of 5 x 25 cm (diameter and length). In these tests, the holes were filled with materials of different density (air, oil and metal), whose attenuation coefficients are well known. The goal of this first test was to assess the response quality of the equipment. The present report is a study comparing computerized tomography equipment CTR-IPEN-CNEN/SP which uses a source of gamma radiation ( 60 Co) and other equipment provided by the Department of Geosciences in the University of Texas (CTUT), which uses an X-ray source (450 kV and 3.2 mA). As a result, the images obtained and the comprehensive study of the usefulness of the equipment developed here strengthened the proposition that the development of industrial computerized tomography is an important step toward consolidating the national technology. (author)

  7. Cranial computerized tomography in children suffering from acute leukemia

    International Nuclear Information System (INIS)

    Metz, O.

    1981-01-01

    Cranial computerized (axial) tomography permits a more complete neurologic supervision of children with acute leukemia and a better knowledge of the frequency and varieties of cerebral complications in leukemia. Endocranial complications in acute leukemia are essentially infiltrative, hemorrhagic, infectious or iatrogenic. Cranial computerized tomography can demonstrate cerebral changes in meningeal leukemia, hemorrhages, calcifications, brain atrophy or leukencephalopathy. The preliminary results of cranial computerized tomography in childhood leukemia suggest that the iatrogenic main lesion of the brain due to combined radiation-chemotherapy is atrophy whereas that of the intrathecal cytostatic therapy is demyelination. Accurate diagnostics and control of possible cerebral complications in therapy of leukemia is essentially for appropriate therapeutic management. For that cranial computerized tomography is the best method to a effective supervision of the brain. (author)

  8. Computerized Tomography and its Applications : a Guided Tour

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1992-01-01

    We present a review of the mathematical principles of computerized tomography. Topics treated include the role of the Radon transform and related transforms, inversion formulas, uniqueness, ill-posedness and stability, practical reconstruction algorithms, and various generalizations such as

  9. Comparison of computerized tomography to sonography, applied in diseases of the pancreas

    International Nuclear Information System (INIS)

    Kluge, K.

    1982-01-01

    The examination results of 418 patients whose epigastria had been examined both by computerized tomography and sonography over 1 week in the time from beginning January 1978 until and of July 1979 were compared with regard to the imaging of the pancreas, reliability, and the specificity and sensitivity in establishing the diagnosis. For the sonographic examination, a compound and a real-time unit were used; the computerized tomography was carried out by means of an equipment of the 3rd generation with a scan time of 4 sec. The screening of the pancreas was significantly better using computerized tomography (99.3% US. 84% with US). As for accuracy, computerized tomography had 92.5% exact diagnoses versus 79.9% obtained by sonography. If, however, we look at the cases in which the pancreas could be screened with both methods the accuracy was almost the same (93.7 CT and 93.3% US). Specificity was almost of the same quality, however, the method of computerized tomography with 0.963 was slightly better than ultrasound with 0.943. As for sensitivity, sonography with 0.838 was better than CT with 0.721. The reason for that is the fact that a big part of the chronic pancreatites (30.3%) were not recognized by means of computerized tomography. (orig.) [de

  10. Assessment of computerized tomography devices in Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Oliveira, Paulo Marcio C.; Horta, Mara Alice Avelar Saraiva; Santana, Priscila do Carmo; Magalhaes, Marcos Juliano

    2011-01-01

    Computed Tomography (CT) is the diagnostic imaging method most commonly performed today. It is a device that is undergoing a technological evolution and their quality control is sorely needed. The image quality evaluation process allow a better diagnosis and control of the patient dose received during image acquisition. The CT doses are higher than other X-ray examination techniques, like a conventional X-ray. Performance evaluation of computed tomography in Minas Gerais is not significant. Therefore, this work aims to analyze 20 CT equipment in Minas Gerais, with parameters according to the national regulatory agency (ANVISA - Agencia Nacional de Vigilancia Sanitaria) in twelve quality control tests. Sixty five percent (65%) of CT equipment evaluated showed excellent results and were not disapproved in any of the tests performed and 30% had failed in only one of the twelve tests performed. The worst result was found in the CT scanners in the test that evaluates the low contrast resolution, where 20% of CT showed non-compliance, followed by the test that evaluates the x-rays collimation beam, where 15% had failed. The tests allowed us to observe that the twenty computerized tomography equipment achieved a great pass rate. Considering that the evaluated CTs performed the quality control tests for the first time, it is concluded that the equipment used in clinics and hospitals are of good quality image and low radiation doses. (author)

  11. Computerized tomography used in non-destructive testing of welded pipes

    Energy Technology Data Exchange (ETDEWEB)

    Iovea, M; Rizescu, C; Georgescu, G; Marinescu, A; Chitescu, P; Sava, T; Neagu, M; Avram, D [Institute of Research and Design for Electrical Engineering, ICPE - Electrostatica Splaiul Unirii 313, Sect. 3, R-74204 Bucharest (Romania)

    1997-12-31

    High quality standards in operation of National Power System is ensured by the use of high performance techniques and systems for Non-Destructive Testing (NDT). In recent years a number of new developments of the non-conventional technologies in the field of NDT have been achieved. In our laboratory there have been developed two computerized technologies using {gamma}-ray computed tomography and ultrasonic imaging methods. The standard techniques for imaging from projection data is computerized tomography. The industrial computerized tomography methods consist in the measurement of thin X - or {gamma}-ray beam attenuation when passing through some selected surface of the tested object, along several directions, so that by means of an adequate mathematical algorithm, a map of linear attenuation coefficients for the scanned surface is obtained. In fact, this map gives the density of materials occurring in the surface plane. Computerized tomography equipment, in various constructive versions, are intended for the following applications: (1) NDT in those fields requiring strict control of product quality, as for instance the nuclear energy, military industry, aeronautics, transportation fields, etc., (2) research in field of materials technology, machine engineering, metallurgy, welding, etc. This paper presents the applications of Computerized Tomography in NDT, by showing the results obtained on welded pipes, as well as the facilities offered by this method. In the final part, the paper presents the concept of a mobile tomography system for industrial pipes testing. (author). 2 figs., 7 refs.

  12. Computerized tomography used in non-destructive testing of welded pipes

    International Nuclear Information System (INIS)

    Iovea, M.; Rizescu, C.; Georgescu, G.; Marinescu, A.; Chitescu, P.; Sava, T.; Neagu, M.; Avram, D.

    1996-01-01

    High quality standards in operation of National Power System is ensured by the use of high performance techniques and systems for Non-Destructive Testing (NDT). In recent years a number of new developments of the non-conventional technologies in the field of NDT have been achieved. In our laboratory there have been developed two computerized technologies using γ-ray computed tomography and ultrasonic imaging methods. The standard techniques for imaging from projection data is computerized tomography. The industrial computerized tomography methods consist in the measurement of thin X - or γ-ray beam attenuation when passing through some selected surface of the tested object, along several directions, so that by means of an adequate mathematical algorithm, a map of linear attenuation coefficients for the scanned surface is obtained. In fact, this map gives the density of materials occurring in the surface plane. Computerized tomography equipment, in various constructive versions, are intended for the following applications: 1) NDT in those fields requiring strict control of product quality, as for instance the nuclear energy, military industry, aeronautics, transportation fields, etc., 2) research in field of materials technology, machine engineering, metallurgy, welding, etc. This paper presents the applications of Computerized Tomography in NDT, by showing the results obtained on welded pipes, as well as the facilities offered by this method. In the final part, the paper presents the concept of a mobile tomography system for industrial pipes testing. (author). 2 figs., 7 refs

  13. Computerized tomography and conventional radiography: A comparison from the standpoint of X-ray physics and technology

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiler, M; Linke, G [Siemens A.G., Erlangen (Germany, F.R.). Unternehmensbereich Medizinische Technik

    1979-08-01

    After a short explantation of the technical foundations of computerized tomography (CT) from terms used in conventional X-ray technique and CT the differences (dose distribution, image character) and similarities (quantum noise, beam quality) of both methods are discussed. Finally possible methods of quantitative evaluation of CT images and computation of longitudinal layers from a series of computerized tomograms are described. (author).

  14. Is 18F-fluorocholine-positron emission tomography/computerized tomography a new imaging tool for detecting hyperfunctioning parathyroid glands in primary or secondary hyperparathyroidism?

    Science.gov (United States)

    Michaud, Laure; Burgess, Alice; Huchet, Virginie; Lefèvre, Marine; Tassart, Marc; Ohnona, Jessica; Kerrou, Khaldoun; Balogova, Sona; Talbot, Jean-Noël; Périé, Sophie

    2014-12-01

    Preoperative ultrasonography and scintigraphy using (99m)Tc-sestamibi are commonly used to localize abnormal parathyroid glands. In cases of discrepant results between scintigraphy and ultrasonography, it is important to rely on another diagnostic imaging modality. (18)F-fluorodeoxyglucose (FDG) and (11)C-methionine positron emission tomography (PET) have been studied, but are imperfect to detect abnormal parathyroid glands. Recently, first cases of abnormal parathyroid glands taking-up radiolabelled choline were discovered incidentally in men referred to (11)C-choline or (18)F-fluorocholine (FCH)-PET/CT for prostate cancer. We checked if FCH uptake was a general feature of adenomatous or hyperplastic parathyroid glands. FCH-PET/CT was performed in 12 patients with primary (n = 8) or secondary hyperparathyroidism (1 dialyzed, 3 grafted) and with discordant or equivocal results on preoperative ultrasonography (US) and/or (123)I/(99m)Tc-sestamibi dual-phase scintigraphy. The results of the FCH-PET/CT were evaluated, with surgical exploration and histopathologic examination as the standard of truth. On a per-patient level, the detection rate of FCH-PET/CT (at least one FCH focus corresponding to an abnormal parathyroid gland in a given patient) was 11/12 = 92%. FCH-PET/CT detected 18 foci interpreted as parathyroid glands and correctly localized 17 abnormal parathyroid glands (7 adenomas and 10 hyperplasias). On a per-lesion level, FCH-PET/CT results were 17 TP, 2 false negative ie, a lesion-based sensitivity of 89%, and 1 false positive. As the main result of this pilot study, we show that in patients with hyperparathyroidism and with discordant or equivocal results on scintigraphy or on ultrasonography, adenomatous or hyperplastic parathyroid glands can be localized by FCH-PET/CT with good accuracy. Furthermore, FCH-PET/CT can solve discrepant results between preoperative ultrasonography and scintigraphy and has thus a potential as a functional imaging modality in

  15. Coupling two iteratives algorithms for density measurements by computerized tomography

    International Nuclear Information System (INIS)

    Silva, L.E.M.C.; Santos, C.A.C.; Borges, J.C.; Frenkel, A.D.B.; Rocha, G.M.

    1986-01-01

    This work develops a study for coupling two iteratives algotithms for density measurements by computerized tomography. Tomographies have been obtained with an automatized prototype, controled by a microcomputer, projected and assembled in the Nuclear Instrumentation Laboratory, at COPPE/UFRJ. Results show a good performance of the tomographic system, and demonstrate the validity of the method of calculus adopted. (Author) [pt

  16. Evaluation of the absorbed dose in odontological computerized tomography

    International Nuclear Information System (INIS)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da; Khoury, Helen J.

    2011-01-01

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  17. Contemporary imaging: Magnetic resonance imaging, computed tomography, and interventional radiology

    International Nuclear Information System (INIS)

    Goldberg, H.I.; Higgins, C.; Ring, E.J.

    1985-01-01

    In addition to discussing the most recent advances in magnetic resonance imaging (MRI), computerized tomography (CT), and the vast array of interventional procedures, this book explores the appropriate clinical applications of each of these important modalities

  18. Strategies of reconstruction algorithms for computerized tomography

    International Nuclear Information System (INIS)

    Garderet, P.

    1984-10-01

    Image reconstruction from projections has progressively spread out over all fields of medical imaging. As the mathematical aspects of the problem become more and more comprehensively explored a great variety of numerical solutions have been developed best suited to such-and-such imaging medical application and taking into account the physical phenomena related to data collection (a priori properties for signal and noise). The purpose of that survey is to present the general mathematical frame and the fundamental assumptions of various strategies; Fourier methods approximate explicit deterministic inversion formula for the Radon transform. Algebraic reconstruction techniques set up an a priori discrete model through a series expansion approach of the solution. The numerical system to be solved is huge when a fine grid of pixels is to be reconstructed; iterative solutions may then be found. Recently some least square procedures have been shown to be tractable which avoid the use of iterative methods. Finally maximum like hood approach incorporates accurately the Poisson nature of photon noise and are well adapted to emission computed tomography. The various strategies will be analysed from both aspects of theoretical assumptions needed for suitable use and of computing facilities, actual performance and cost. In the end we take a glimpse of the extension of the algorithms from two dimensional imaging to fully three dimensional volume analysis in preparation of the future medical imaging technologies

  19. Motion Estimation and Compensation Strategies in Dynamic Computerized Tomography

    Science.gov (United States)

    Hahn, Bernadette N.

    2017-12-01

    A main challenge in computerized tomography consists in imaging moving objects. Temporal changes during the measuring process lead to inconsistent data sets, and applying standard reconstruction techniques causes motion artefacts which can severely impose a reliable diagnostics. Therefore, novel reconstruction techniques are required which compensate for the dynamic behavior. This article builds on recent results from a microlocal analysis of the dynamic setting, which enable us to formulate efficient analytic motion compensation algorithms for contour extraction. Since these methods require information about the dynamic behavior, we further introduce a motion estimation approach which determines parameters of affine and certain non-affine deformations directly from measured motion-corrupted Radon-data. Our methods are illustrated with numerical examples for both types of motion.

  20. Patient surface doses in computerized tomography examinations

    International Nuclear Information System (INIS)

    Vekic, B.; Kovacevic, S.; Ranogajec Komor, M.; Duvnjak, N.; Marusic, P.; Anic, P.; Dolencic, P.

    1996-01-01

    Computed tomography (CT) has become a major source of the population exposure to diagnostic x-rays, and acknowledge of the doses delivered by the CT equipment has become very important. Considerable efforts should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The conditions of exposure in CT are quite different from dose in conventional x-ray imaging. This has required the development of specific techniques for assessing patient dose from CT. The aims of this work were to determine the dose delivered to various organs of patients undergoing computed tomography of abdomen, thorax, pelvis and kidney as measured on the surface of the body and to estimate the risk to the patients. Dosimetric measurements were performed at two different CT scanners (Siemens SOMATOM DR-H ver. HC-1 and Shimadzu SCT-4500TE). The dose absorbed by different organs (gonads, chest, thyroid and eye lens) and by the examined part of the body of 95 patients of various sex and age were measured with TLD-700. The doses absorbed by different organs during the diagnostic CT examination of the body depend on the technical parameters, such as the number of scan, mAs, the thickness of scans, scanning times, tube voltage and other characteristics, some of each depend on the type and severity of illness. Clinical parameters, such as patient size and composition, and patient cooperation with regard to the control and motion, also influence the dose and the image quality. The highest dose measured in this study (89.19 mGy) was delivered to kidney during CT examination of this organ. (author)

  1. Comparison of preoperative computerized tomography scan imaging of temporal bone with the intra-operative findings in patients undergoing mastiodectomy

    International Nuclear Information System (INIS)

    Gerami, H.; Naghavi, E.; Wahabi-Moghadam, M.; Forghanparast, K.; Akbar, Manzar H.

    2009-01-01

    Objective was to compare the consistency rates of pre- and intra-operative radiological findings in patients with chronic suppurative otitis media (CSOM). In a cross-sectional study, 80 patients with CSOM underwent pre-operative CT scanning and we compared the results with intra-operative clinical findings during mastiodectomy from 2000-2004 in the Otology Department, Amiralmomenin Hospital of Guilan Medical University, Rasht, Iran. Sensitivity, specificity, positive and negative predictive value of CT scan in tympanic and mastoid cholesteatoma, ossicular chain erosion, tegmentympani erosion, dehiscence of facial canal, lateral semicircular canal (LSCC) fistula were assessed. Then, correlation between radiological findings and intra-operative findings were calculated. The mean age of patients was 27.9+-16.3 years. Mostly were males (n=57 [71.3%]). Correlation of preoperative radiological images with intra-operative clinical findings were moderate to good on tympanic cholesteatoma, mastoid cholesteatoma and ossicular chain erosion, but weak and insignificant in cases of tegmen erosion, facial canal dehiscene and LSCC fistulae. Preoperative CT scan may be helpful in decision-making for surgery in cases of cholesteatoma and ossicular erosion. Despite of limitations radiological scanning is a useful adjunct to management of CSOM. (author)

  2. Radiation conditions for computerized tomography: determination and comparison

    International Nuclear Information System (INIS)

    Andrade, Lucio das Chagas de

    2016-01-01

    Radiology is the practice in which radiation beams, usually radiation X are used to produce an image of the human body in order to obtain a diagnosis, for example, to evaluate a pathological condition by computerized tomography (CT). Although the computerized tomography diagnostic potential is unquestionable, caution must be taken because the doses are almost always higher than the observed in conventional radiology procedures. The ionization chamber used for dosimetry in CT is a unsealed cylindrical chamber with 10 cm and 15 cm of sensitive length. A typical characteristics of this camera is its uniform response to radiation incident at all angles around its axis. The revised edition of IEC 61267 (2005) brought as an innovation the radiation conditions for computed tomography, RQT, that simulate non-attenuated beam and are used in special CT applications. This study aims to establish the necessary conditions to obtain radiation pattern beam computed tomography, RQT, and a calibration laboratory implementation for pencil ionization chambers used in the beam dosimetry produced by these scanners in the Metrology National Laboratory of Ionizing Radiation (LNMRI). In the implementation of RQT conditions we were found that the ratio of kerma rates in the air, with or without additional filtration equivalent to the first HVL (half-value layer), are in accordance with IEC 61267 (2005), which provides a range between 48.5% and 51.5% for each quality. The LNMRI characterized the radiation conditions of RQT series (IEC, 2005), obtaining a percentage of 49.6% for the RQT 8, 50% for the RQT 9 and 50,4% for the RQT 10. With the substitution of the total additional filtration RQT qualities, composed by Al + Cu and by a total filtration composed by copper (Cu) only, it can be seen the emergence of a similar RQT quality named Quality Copper Tomography - QCT. The results of the calibration, the RQT and QCT qualities, had expanded uncertainties with a confidence level 95.45%, less

  3. Analysis of concrete material through gamma ray computerized tomography

    International Nuclear Information System (INIS)

    Oliveira Junior, J.M. de

    2004-01-01

    Computerized Tomography (CT) refers to the cross sectional imaging of an object from both transmission or reflection data collected by illuminating the object from many different directions. The most important contribution of CT is to greatly improve abilities to distinguish regions with different gamma ray transmittance and to separate over-lying structures. The mathematical problem of the CT imaging is that of estimating an image from its projections. These projections can represent, for example, the linear attenuation coefficient of γ-rays along the path of the ray. In this work we will present some new results obtained by using tomographic techniques to analyze column samples of concrete to check the distribution of various materials and structural problems. These concrete samples were made using different proportions of stone, sand and cement. Another set of samples with different proportions of sand and cement were also used to verify the outcome from the CT analysis and the differences between them. Those samples were prepared at the Material Laboratory of Faculdade de Engenharia de Sorocaba, following the same procedures used in real case of concrete tests. The projections used in this work was obtained by Mini Computerized Tomograph of Uniso (MTCU), located at the Experimental Nuclear Physics Laboratory at University of Sorocaba. This tomograph operates with a gamma ray source of 241 Am (photons of 60 keV and 100 mCi of intensity) and a NaI(Tl) solid state detector. The system features translation and rotation scanning modes, a 100 mm effective field of view, and 1 mm spatial resolution. The image reconstruction problem is solved using Discrete Filtered Backprojection (FBP). (author)

  4. Impact of Multidetector Computerized Tomography (MDCT) On The General Population

    Energy Technology Data Exchange (ETDEWEB)

    Leite, B.B.; Ribeiro, N.C. [Servico de Radiologia, Hospital de Curry Cabral, Rua da Beneficencia, 8, 1069-166 Lisboa (Portugal)

    2009-05-15

    Multidetector computerized tomography (MDCT) appeared in the early 1990s, as a technological evolution of computerized tomography. As one would expect, the evolution continues and, each year, more powerful equipments appear, with new medical applications. However, the general use of this technique has lead to the dramatic increase on the general population irradiation. Special concern is required regarding the most vulnerable groups, like the pediatric population, the pregnant and the young female. Due to a larger awareness of this irradiation risks, some initiatives have been developed, coming from different areas, aiming to maximize the benefit to risk ratio of MDCT. (author)

  5. Recurrent lymph node metastases after craniocervical tumours: Computerized tomography

    International Nuclear Information System (INIS)

    Helmberger, H.; Lenz, M.; Kersting-Sommerhoff, B.; Bautz, W.; Kretz, S.

    1992-01-01

    A total of 544 CT examinations of the craniocervical region carried out in 231 patients were analyzed on a retrospective basis in order to assess the clinical value of contrast-enhanced computerized tomography, being carried out either for comparison with or in combination with clinical control examinations, in the post-therapeutic surveillance of patients treated for craniocervical tumours. The diagnostic accuracy attained with computerized tomography in the detection of recurrent lymph node metastases was 95% and thus superior to that determined for clinical control examinations (80%). (orig./GDG) [de

  6. Contribution to differential diagnosis of lumbar spine disc hernia by computerized tomography

    International Nuclear Information System (INIS)

    Dolansky, J.

    1989-01-01

    The significance is discussed of computerized tomography in differential diagnosis of disc hernias of the lumbar spine. A simple technique is described that allows to differentiate disc hernias from epidural vein varices. It mostly includes repeat imaging of the same body section and/or the application of a contrast medium. (L.O.). 2 figs., 4 refs

  7. Filtered Bessel functions in computerized tomography

    International Nuclear Information System (INIS)

    Rathore, R.K.S.; Munshi, P.; Bhatia, V.K.; Pandimani, S.

    1988-01-01

    Computer Aided Tomography (CAT) is widely used in the medical imaging area for the detection of cancerous tissues. It has also proved to be a good technique for measuring point-density (void-fraction) in two-phase flow systems. The present day CAT-scanners employ alogorithms which are essentially a discrete implementation of the Radon Inversion Formulae. These methods of reconstructing density distributions are fast and easy to implement. The present work is an attempt to simplify (and consequently to speed-up) the existing algorithms for the cases of radially symmetric density distribution. The method uses Radon Inversion Formulae and involves Bessels's Function of Fourier frequency. The algorithm was tested on some known distributions and the reconstruction is excellent. Data for bubbly-flow was also processed to obtain a point density distribution. The range of investigation was 0.6 ≤ ≤ 0.9 g/cm 3 , where ' ' denotes average cross-sectional value. The values of CT > are within ±0.03 g/cm 3 of the true values , for the data sets considered. The results are comparable with another simple method involving radial polynominals. It is observed that the simplified Radon Inversion Formulae for the radially symmetric case gives good results and can be implemented with ease. (orig.)

  8. Study of computerized tomography using neutron beam

    International Nuclear Information System (INIS)

    Pereira, W.W.

    1991-05-01

    This paper aims to demonstrate the advantages, shortcomings and complementaries of a tomography development using neutrons over the one employing gamma rays in the context of their applications to non destructive essays. A simulated experimental study was performed in order to compare the two aforementioned tomographic procedures as applied to some materials. These materials were chosen for their clear advantages and complementaries as, for instance, aluminium, iron, plastic and aluminium hydroxide. In this work two tomographic systems, are employed both with parallel beams. The first with a gamma radiation source (Caesium-137), with an energy of 662 KeV and an activity of 3,9 x 10 9 Bq (100 mCi) and the second one employing a neutron source, the Argonaut Reactor of the Instituto de Engenharia Nuclear, IEN/CNEN, from where the thermal neutron beam of about 10 5 n/(cm.s) was obtained. It is possible to conclude from the simulated and experimental results, by means of image analysis and distortion measurements, that for a given material the adequate radiation and its energy may be chosen so as to better characterize it. (author)

  9. Dosimetry of computerized tomography in the evaluation of hip dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Guyer, B.; Bassano, D.A.; Levinsohn, E.M.; Smith, D.S.; Cady, R.B.

    1984-07-01

    The usefulness of computerized tomography (CT) in the assessment of hip dysplasia has recently been given attention in the literature and concern regarding radiation dose has been raised. This study was undertaken to measure the radiation dose, both in and out of plaster, for plain films, arthrography, tomography, and CT. A method is suggested to reduce dosage by 80% without compromising diagnostic information. Our experience with 25 scans of patients aged 4 months to 39 years is presented.

  10. Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors

    OpenAIRE

    Tong Yu; Jun Gao; Zhi-Min Liu; Qi-Feng Zhang; Yong Liu; Ling Jiang; Yun Peng

    2017-01-01

    Background: Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors...

  11. Computerized tomography in the examination of the orbit

    International Nuclear Information System (INIS)

    Ammerich, H.; Wackenheim, A.; Golabek, R.

    1980-01-01

    The importance of computerized tomography in the ophtalmological diagnosis is discussed. A great value of the information obtained by this not cumbersome method is stressed. The findings achieved this method in the most frequent diseases of the eyeball, orbit and neighbouring anatomical structures are described. (author)

  12. Contribution of computerized tomography to orbit fracture diagnosis

    International Nuclear Information System (INIS)

    Nemeth, T.; Sobota, J.

    1984-01-01

    Suitability and specificity of examinations using computerized tomography are discussed for diagnoses fractures of the orbit including accurate anatomical localization of traumatic changes. The possibility of accurate assessment of the drop of the floor of the orbit which is essential for determination of the thickness of the bone or cartilaginous graft under the eyeball is also important

  13. Emission computerized-tomography and determination of local brain function

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Alavi, A.; Reivich, M.; Edwards, R.Q.; Fenton, C.A.; Zimmerman, R.A.

    1975-01-01

    Methods for the three dimensional reconstruction of /sup 99m/Tc brain scans are described. The diagnostic advantages of computerized tomography in the localization of brain tumors and in measurements of local cerebral blood flow are discussed. (U.S.)

  14. Cranial Computerized Tomography In The Evaluation Of Stroke ...

    African Journals Online (AJOL)

    206 patients clinically diagnosed as stroke / cerebrovascular accidents (CVA) were investigated using computerized tomography (CT) scan. 19 patients (9%) had normal scan. While 20(9.7%) had other lesions including atrophy and tumours. Of the 167 (18. %) patients proven to have suffered a cerebro- vascular accident ...

  15. Significance of computerized tomography and nasal cytology in the ...

    African Journals Online (AJOL)

    Ehab

    assessment of sinus disease in asthmatic children. Rhinosinusitis is a common asthma comorbidity. Nasal eosinophil or neutrophil score >0.5 provides a better predictive value for rhinosinusitis compared to total serum IgE. Keywords: computerized tomography, nasal sinus, asthma, sinusitis, allergic rhinitis, children.

  16. Radiation exposure of the gonads in infant brain computerized tomography

    International Nuclear Information System (INIS)

    Berndt, L.; Rosenkranz, G.; Tellkamp, H.

    1988-01-01

    In 61 babies and infants the gonadal dose due to brain computerized tomography was determined over the symphysis by thermoluminescent dosimetry. The average radiation dose was 43 mGy corresponding with data reported. Shielding of the testes in infants is an additional burden and worth discussing because of the low absolute gonadal dose

  17. Radio astronomical interferometry and x-ray's computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L F [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

    1982-01-01

    Radio astronomical interferometry and computerized tomography are techniques of great importance for astronomy and medicine, respectively. In this paper we emphasize that both techniques are based on the same mathematical principles, and present them as an example of interaction between basic and applied science.

  18. Study of Pelvicaliceal Anatomy by Helical Computerized Tomography

    International Nuclear Information System (INIS)

    Al-Qahtani, Fahd N.; Ali, Gaber A.; Kamal, Baher A.; Taha, Saud A.

    2003-01-01

    To evaluate the role of 3-dimensional images produced by computerized tomography (CT), using intravenous contrast, to study pelvicaliceal anatomy.This might be of help in endourological procedure. The study was conducted in the King Fahd Hospital of the University, King Faisal University. Dammam,Kingdom of Saudi Arabia. The study took place from July 2002 through to October 2002 .Helical CT was carried for patients who were investigated using excretory urography for any reason. A CT was carried out to the kidneys only within 10 minutes ( between 5 and 15 minute films of excretory urography).Images were reprocessed by 3-dimension construction after subtracting all structures except for the palvicaliceal system. Thity-six normal kidneys were studied. The upper pole was drained by a single caliceal infundibulum in all 36(100%) kidneys.the middle segement of the kidney was drained by 2 infundibula in 32 (89%) kidneys. Four (11%) kidneys have no middle caliceal infudibula. The lower pole was drained by 2 caliceal infundibula in 23 (64%) and a single infundibulum in 13 (36%) kidneys. The minor calices draining each renal segment were seen clearly. Three-dimensional images derived by helical CT are feasible for evaluating the anatomy of palvicaliceal system,and, can be of help in endourological procedures. (author)/

  19. Computerized tomography in diagnosis of cerebrocranial injury

    International Nuclear Information System (INIS)

    Kornienko, V.N.; Vasin, N.Ya.; Kuz'menko, V.A.

    1987-01-01

    The method of computerized tomographical examination are presented. Th KT-characters of concussion of the brain, its contusion of different severity, compressions in case of traumatic intracranial hematomas, contusion injuries, brain edema and different aftereffects of cerebrocranial injury are given. On the basis of comparison of the data of clinical and KT examination the dynamics of intracranial traumatic injuries in the course of treatment is described. The problems of therapeutic and surgical tactics depending on the degree and form of intracranial structure injuries and the phase of clinical course of posttraumatic process are discussed

  20. Computerized tomography of unipapillary kidney - case report

    International Nuclear Information System (INIS)

    Bauab Junior, T.; Crosera, P.C.; Zerati Filho, M.

    1988-01-01

    A case of unipapillary kidney which was evaluated by computed tomography is reported. A review of the literature shows 14 previously reported cases, but none evaluated by CT. The authors also emphasize the lesions that course along with the unipapillary kidney. (author)

  1. Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography and (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for recurrent prostate carcinoma: results of a prospective clinical trial.

    Science.gov (United States)

    Schuster, David M; Nieh, Peter T; Jani, Ashesh B; Amzat, Rianot; Bowman, F Dubois; Halkar, Raghuveer K; Master, Viraj A; Nye, Jonathon A; Odewole, Oluwaseun A; Osunkoya, Adeboye O; Savir-Baruch, Bital; Alaei-Taleghani, Pooneh; Goodman, Mark M

    2014-05-01

    We prospectively evaluated the amino acid analogue positron emission tomography radiotracer anti-3-[(18)F]FACBC compared to ProstaScint® ((111)In-capromab pendetide) single photon emission computerized tomography-computerized tomography to detect recurrent prostate carcinoma. A total of 93 patients met study inclusion criteria who underwent anti-3-[(18)F]FACBC positron emission tomography-computerized tomography plus (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for suspected recurrent prostate carcinoma within 90 days. Reference standards were applied by a multidisciplinary board. We calculated diagnostic performance for detecting disease. In the 91 of 93 patients with sufficient data for a consensus on the presence or absence of prostate/bed disease anti-3-[(18)F]FACBC had 90.2% sensitivity, 40.0% specificity, 73.6% accuracy, 75.3% positive predictive value and 66.7% negative predictive value compared to (111)In-capromab pendetide with 67.2%, 56.7%, 63.7%, 75.9% and 45.9%, respectively. In the 70 of 93 patients with a consensus on the presence or absence of extraprostatic disease anti-3-[(18)F]FACBC had 55.0% sensitivity, 96.7% specificity, 72.9% accuracy, 95.7% positive predictive value and 61.7% negative predictive value compared to (111)In-capromab pendetide with 10.0%, 86.7%, 42.9%, 50.0% and 41.9%, respectively. Of 77 index lesions used to prove positivity histological proof was obtained in 74 (96.1%). Anti-3-[(18)F]FACBC identified 14 more positive prostate bed recurrences (55 vs 41) and 18 more patients with extraprostatic involvement (22 vs 4). Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography correctly up-staged 18 of 70 cases (25.7%) in which there was a consensus on the presence or absence of extraprostatic involvement. Better diagnostic performance was noted for anti-3-[(18)F]FACBC positron emission tomography-computerized tomography than for (111)In-capromab pendetide single

  2. Quality criteria in computerized tomography of the chest

    International Nuclear Information System (INIS)

    Doehring, W.

    1985-01-01

    The quality of thoracical computerized tomography (CT) - like any other CT examination - depends from the quality of the equipment used, from the skill of the examinor and the properties of the patient. Concerning computerized chest tomograms, rapid scan equipment should be used only and slow translation - rotation systems should not be used any more. Whereas the quality of computerized tomograms may be influenced by the patient in the scanning process only, the examining physician will decisively influence the possible informative value of the examination also in the reconstruction of the CT value matrix, in single demonstration of CT values and, possibly, in additional measurement value processing as well as in the interpretation of findings. Use of equipment should always consider the technical potential provided by the equipment to be oriented to the clinical issue, and the conditions preset by the patient. (orig.) [de

  3. Diffuse nesidioblastosis diagnosed on a Ga-68 DOTATATE positron emission tomography/computerized tomography

    International Nuclear Information System (INIS)

    Arun, Sasikumar; Mittal, Bhagwant Rai; Shukla, Jaya; Bhattacharya, Anish; Kumar, Praveen

    2013-01-01

    The authors describe a 50 days old pre-term infant with persistent hyperinsulinemic hypoglycemia of infancy in whom 68 Ga DOTATATE positron emission tomography/computerized tomography scan showed diffusely increased tracer uptake in the entire pancreas with no abnormal tracer uptake anywhere else in the body, suggestive of a diffuse variant of nesidioblastosis. (author)

  4. Sonography and computerized tomography in a comparison in renal mass diseases

    International Nuclear Information System (INIS)

    Brommer, M.

    1981-01-01

    One hundred and thirteen patients with renal mass processes were examined sonographically and by computized tomography. The diagnosis was assured in 32 cases histologically, in 40 cases angiographically clinically and by the course and in 41 cases only clinically and by the course resp. by sonographic and computerized tomography control studies. The accuracy of a hit in sonography is smaller compared with computerized tomography with fast image formation. However, due to its relative safety, it is judged as the most useful technique for a first diagnossis of renal masses after ureographic diagnostic of excreta. A diagnostic procedure is proposed in which the number of necessary angiographies and diagnostic sampling surgery can be considerably reduced. (orig.) [de

  5. Computerized axial tomography : the tool in osseointegrated dental implants

    International Nuclear Information System (INIS)

    Fernandez-Lopez, Otton

    2002-01-01

    Failure rates in rehabilitations with osseointegrated implants are handled through appropriate radiographic preoperative planning. The appropriate length of the implant without running the risk of a perforation of vital structures, has been determined by a radiographic diagnosis. Computerized and conventional axial tomography have proved to be invaluable elements for pre-surgical evaluation. A radiologic guidance is elaborated to perform a computerized axial tomography (CT) of maxillary bones in totally edentulous patients. Surgical guides are constructed from a wax-up emanated from the information of the CT. The CT has proven to be an radiographic indispensable element to achieve the surgical-prosthetic success in osseointegrated dental implants. The CT has allowed the realization of a precise wax-up for making of surgical guide and a precise temporary prostheses in positioning of osseointegrated implants, with the consequent saving time and money for the rehabilitator and patient [es

  6. Prognosis of the computerized tomography in the severe head injury

    International Nuclear Information System (INIS)

    Garcia-Nieto, J.J.; Lorenzo Dominguez, M.T.; Martin Sanchez, M.J.; Sanchez Gonzalez, E.

    1991-01-01

    A prospective study is made with sixty five people affected of severe head injury, that is to say, with eight or less points in the Glasgow Coma Scale (GCS), when they get to the hospital. They are studied by computerized tomography at the income, but also, three and seven days after arriving. In this way, we appraise the type of the lesion the intensity and the possible effect-wass, considering in the last case, three features: a) ventricular collapse; b) the mean line structure s shift; c) perimesencefalic cisterns affectation. The findings of this study, are parametized and we were able to introduce them into a computer, getting. The relations between these findings ands the end-results. These last ones appraised throungh the Glasgow Outcome Scale (GOS). We could confirm, that certain findings in the computerized tomography have and unavoidable prognosis, where as others have a better prognosis. (Author)

  7. Method of evaluation of diagnostics reference levels in computerized tomography

    International Nuclear Information System (INIS)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  8. Preoperative localization of parathyroid tumor by computerized tomography

    International Nuclear Information System (INIS)

    Kan, Seiji; Hiraishi, Koji; Nakamura, Shoichiro; Yamamoto, Schuzo; Odachi, Motoaki; Yamashita, Toshiyuki.

    1984-01-01

    Five patients of primary hyperparathyroidism with urolithiasis underwent CT-scanning for the preoperative localization of parathyroid tumor. The tumor was identified in all patients but one, who had a multiple adenomatous goiter. In this case, postoperative observation of the CT-scan revealed the parathyroid tumor. It appears that if the size of the parathyroid tumor is about 1cm in diameter, there is a high possibility of preoperative localization by computerized tomography. (author)

  9. Computerized tomography of kidneys in long-term dialysis patients

    International Nuclear Information System (INIS)

    Srp, A.; Merta, M.; Sulkova, S.

    1990-01-01

    A cohort is presented of 21 patients with irreversible kidney failure who were examined by computerized tomography in 1986-1987. The mean period of dialysis programme was 5.7 years, chronic glomerulonephritis and interstitial nephritis were the basic conditions. According to the results of computerized tomography, the patients were divided into four groups: 1. the presence of cysts or tumors was not established, 2. multiplecysts were found in bilateral location, 3. less than 3 cysts were found, 4. kidney tumor was diagnosed. The factor causing the development of the cysts was not identified. It is presumed that the disease is caused by a biologically active substance which is not efficiently dialyzed. The examination of the kidneys is recommended in patients in the stage of chronic kidney insufficiency and particularly in patients on dialysis for a long period of time. The recommended examination uses computerized tomography, and attention should be given to the possible occurence of acquired cystic disease or kidney tumors. (author). 6 figs., 8 refs

  10. A case of neurosarcoidosis monitored by computerized tomography

    International Nuclear Information System (INIS)

    Kubota, Toshihiko; Kimura, Makoto; Komai, Toshio; Yamamoto, Shinjiro; Yamamura, Itaru

    1979-01-01

    A 21-year-old man complaining of impaired visual acuity was admitted to the hospital. Physical examinations showed asymptomatic bilateral hilar lymphadenopathy and cardiomyopathy. Neurological findings disclosed left blindness and right temporal hemianopsia. Computerized tomography, pneumoencephalography and carotid angiography revealed a suprasellar mass. After the admission, the following symptoms deteriorated rapidly: diabetes insipidus, anterior pituitary dysfunction, visual loss of the right eye and hepatomegaly, subsequently consciousness disorder developed during a month though he was given steroids. The more deteriorated the clinical course, the larger the suprasellar mass with expanding hydrocephalus in repeated computerized tomographies. After the ventriculo-peritoneal shunt operation, consciousness improved. Diabetes insipidus also improved after Diabenese administration. On the operation, adhesive arachnoiditis over all the frontotemporal cortex and swollen purplishly red optic chiasm were exposed. Microscopically the specimen from the optic chiasm evidenced a sarcoid granuloma which composed of epitheroid cells, lymphocytes and multi-nucleated giant cells with numerous hemosiderin droplets. The specimen from the surface of the left frontal lobe showed thick fibrosis in the subarachnoid space. By steroids therapy, diabetes insipidus and hepatomegaly disappeared five months after the admission, whereas blindness never recovered. He died of developed status epilepticus eleven months after the admission. The authors reviewed neuroradiological findings of neurocarcoidosis based on pathological findings in the literature, and emphasized that computerized tomography was the most useful for diagnosis and treatment of neurosarcoidosis. (author)

  11. Computerized tomography and staging of bladder tumors

    International Nuclear Information System (INIS)

    Wozniak, A.; Luongo, A.; Nogueira, A.

    1982-01-01

    Computed Tomography (CT) has been employed in 13 patients with bladder tumors; 8 of them subsequently underwent surgery. Concordance between CT and pathological staging ranged in 90% of accurate results. Our data are discussed and compared to those of other authors in the literature. Staging was carried out according to the International Union Against Cancer. CT proved to be very accurate in the assessment of local and regional spread of tumor, limphatic progression and early detection of ureteral obstruction, as well as diagnosis of distant metastasis in selected patients. In poor candidates for surgery CT provided invaluable data to be used for localizing fields of radiation therapy. CT is a very well tolerated procedure, it is therefore suitable in subsequent treatment control. (Author) [pt

  12. Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions

    International Nuclear Information System (INIS)

    Coelho, Marcus Vinicius Cavalcante

    1998-01-01

    In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author)

  13. Contrast media are helpful in computerized tomography

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Contrast media very often can decisively improve the image contrasts, and thus contribute to making the differential diagnosis more specific. This survey of a symposium on the current status of CT refers particularly to the lectures that discussed the use of contrast media for neuroradiology, and the risks involved. (orig.) [de

  14. Dose assessment in pediatric computerized tomography

    International Nuclear Information System (INIS)

    Vilarinho, Luisa Maria Auredine Lima

    2004-01-01

    The objective of this work was the evaluation of radiation doses in paediatric computed tomography scans, considering the high doses usually involved and the absence of any previous evaluation in Brazil. Dose values were determined for skull and abdomen examinations, for different age ranges, by using the radiographic techniques routinely used in the clinical centers investigated. Measurements were done using pencil shape ionization chambers inserted in polymethylmethacrylate (PMMA) phantoms. These were compact phantoms of different diameters were specially designed and constructed for this work, which simulate different age ranges. Comparison of results with published values showed that doses were lower than the diagnostic reference levels established to adults exams by the European Commission. Nevertheless, doses in paediatric phantoms were higher than those obtained in adult phantoms. The paediatric dose values obtained in Hospitals A and B were lower than the reference level (DRL) adopted by SHIMPTON for different age ranges. In the range 0 - 0.5 year (neonatal), the values of DLP in Hospital B were 94 por cent superior to the DRL For the 10 years old children the values of CTDI w obtained were inferior in 89 por cent for skull and 83 por cent for abdomen examinations, compared to the values published by SHRIMPTON and WALL. Our measured CTDI w values were inferior to the values presented for SHRIMPTON and HUDA, for all the age ranges and types of examinations. It was observed that the normalized dose descriptors values in children in the neonatal range were always superior to the values of doses for the adult patient. In abdomen examinations, the difference was approximately 90% for the effective dose (E) and of 57%.for CTDI w . (author)

  15. Emission computerized tomography (ECT) - an introduction

    International Nuclear Information System (INIS)

    Oberhausen, E.

    1985-01-01

    It is first shown that the qualitative requirement of ECT, with regard to both the gamme camera and the possibilities of the computer system, are much higher than those of normal planar scintigraphy. A comparison of planar scintigrams and ECT pictures demonstrates that the SPECT technique is clearly superior, especially in cases of expected superpositions by tissue activity. The factors determing the visuability of lesions in the ECT pictures are discussed. Finally a classification of scintigraphic examinations is proposed to show the applications of planar imaging and those of ECT technique. This proposal is thought to stimulate further discussions. (orig.) [de

  16. Single-Photon Emission Computerized Tomography (SPECT in Neuropsychiatry: A Review

    Directory of Open Access Journals (Sweden)

    B. K. Puri

    1992-01-01

    Full Text Available Cranial single-photon emission computerized tomography (SPECT or SPET can now give regional cerebral blood flow images with a resolution approaching that of positron emission tomography (PET. In this paper, the use of high resolution SPECT neuroimaging in neuropsychiatric disorders, including Alzheimer's disease, multi-infarct dementia, Pick's disease, progressive supranuclear palsy, Korsakoff's psychosis, Creutzfeld-Jakob disease, Parkinson's disease, Huntington's disease, schizophrenia, mood disorders, obsessive–compulsive disorder, HIV infection and AIDS is reviewed. Finally, further potential research and clinical uses, based on ligand studies, are outlined.

  17. Efficacy of virtual computerized tomography laparoscopy for retroperitoneoscopic nephrectomy

    International Nuclear Information System (INIS)

    Shigeta, Masanobu; Kadonishi, Yuichi; Yasumoto, Hiroaki; Mita, Koji; Usui, Tsuguru; Marukawa, Kazushi

    2004-01-01

    Retroperitoneoscopic nephrectomy is less invasive than open nephrectomy, and is an alternative surgical procedure for renal tumors and upper urothelial tumors. We evaluated the efficacy of virtual computerized tomography laparoscopy (VCTL) as a navigator for retroperitoneoscopic nephrectomy to ascertain the correct anatomy of the renal hilum pre-operatively under the retroperitoneoscopic view. Seventy-three kidneys with localized renal tumors (n=44), upper urothelial tumors (n=23), or benign renal disease (n=6) underwent multidetector-row CT. VCTL was carried out by the volume-rendered technique. The findings were compared with those of real retroperitoneoscopy. After the operation, each operator scored 1 to 5 in evaluating the usefulness of virtual retroperitoneoscopy (score 5 indicated very useful). The percentages of renal arteries depicted by VCTL compared with those noted during real surgery were 93% for kidneys with renal tumors, 100% for upper urothelial tumors and 83% for benign renal disease. Two renal arteries of 2 kidneys were not detected by virtual imaging. These were about 1 mm in diameter and directly branched from the aorta, however retroperitoneoscopic nephrectomy was performed uneventfully. VCTL depicted all the renal veins. The anatomy of the renal hilum seen on VCTL and real retroperitoneoscopy was identical, without the minor angle deviation caused by drawing the kidney during the operation. The average score for the usefulness of VCTL was 4.1, ranging from 3 to 5. The accurate surgical anatomy of the renal hilum could be predicted in almost all patients pre-operatively. VCTL is an excellent navigator for retroperitoneoscopic nephrectomy. (author)

  18. Contribution of computerized tomography to diagnosis of primary hyperaldosteronism

    International Nuclear Information System (INIS)

    Hrabaneova, J.; Stribrna, J.; Bultasova, H.; Karasova, L.; Placer, Z.; Pinsker, P.

    1987-01-01

    Two cases are reported of computerized tomography (CT) examination for proof of suspect primary hyperaldosteronism caused by adenoma of the adrenals. The findings were then confirmed surgically and histologically. CT was again found to be an invaluable tool for differential diagnosis of this condition, which spared the patients demanding invasive examinations and clearly differentiated primary hyperaldosteronism from adrenal cortex hyperplasia. This is mainly important for the fact that adenoma or more rarely carcinoma causing primary hyperaldosteronism can surgically be removed. (L.O.). 2 figs., 2 tabs., 6 refs

  19. Diagnostic perspectives of mobile x-ray computerized tomography

    International Nuclear Information System (INIS)

    Portnoj, L.M.; Dibirov, M.P.; Denisova, L.B.

    1992-01-01

    Mobile x-ray computerized tomography (CT) and an organization and methodological scheme of its application were assessed. CT is realized in special hospitals of large regions, where the patients with the optimal indications for CT are assembled. Over 15000 examinations were carried out with the use of the suggested CT program over 4 years, that resulted in detection of 1295 brain tumors, 804 cases with neoplastic involvement of the abdominal cavity and the retroperitoneal space. Wide application of mobile CT devices according to the program will help to decide the problem of unavailability of such examinations. One mobile device may replace 3 permanent CT devices

  20. Computerized tomography anatomy of the kidneys and retroperitoneal space

    International Nuclear Information System (INIS)

    Savchenko, A.P.; Mamaev, V.V.; Pkhakadze, Eh.G.

    1989-01-01

    The authors described the anatomy of the kidneys and retroperitoneal space in health on the basis of computerized tomography (CT) of 90 patients. Five typical levels in CT (ensuring all necessary data on roentgenomorphological trains of the kidneys and retroperitoneal space in the kidney area) were singled out. Some roentgenometric data on kidney cross-sections as well as the quantitative densitometric characterization of the parenchyma of the kidneys, renal sinus and adjacent tissues were presented. X-ray anatomy of the renal fiscia, pararenal space and perirenal fatty space of the kidney with different parts of the tetroperitoneal space was described

  1. Computerized analysis of brain perfusion parameter images

    International Nuclear Information System (INIS)

    Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

    2007-01-01

    Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

  2. Clinical neuroanatomy and diagnostic imaging of the skull. Computerized tomography and nmr imaging. 2. rev. and enlarged ed. Klinische Neuroanatomie und kranielle Bilddiagnostik. Computertomographie und Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmann, H.J. (Medizinische Hochschule Hannover (Germany). Abt. Neuroanatomie); Weinrich, W. (Krankenhaus Nordstadt, Hannover (Germany). Neurologische Klinik)

    1991-01-01

    In the last few years, the techniques of CT, MRI, PET and utrasonography have been improved in their diagnostic efficiency, but in spite of the much enhanced resolution achievable with the new techniques, a large part of the neurofunctional systems that are of great significance to clinical diagnostic evaluation remains in the dark. The local structure of the neurofunctional systems is derived from the data describing the position of the conductive structures such as cerebral ventricles or typical cerebral sulci or gyri. A good knowledge of the three-dimensional topography of the neuroanatomy in the skull is required for this purpose, and this is what the book at hand is intended to confer. The arteries and their vascular environment are shown in the frontal, sagittal and axial plane and are compared with drawings produced from angiographies. The information given covers the cranium viscerale, the craniocervical neighbouring areas, and the motor innervation areas of the skull. The term 'diagnostic imaging of the skull' comprises the whole head and the transitional zones. The illustration of the neurofunctional system anatomy in the tomogram presented in this book is a source of information that may serve as a guide for pathfinding in CT, MRI, PET and ultrasonography. In addition, the knowledge found in the book will help to assign clinical data to pathologic findings revealed by CT or MRI. (orig.) With 596 mostly coloured figs.

  3. Computerized tomography of the vertebral column following traumatic lesion

    International Nuclear Information System (INIS)

    Taenzer, B.; Gmelin, E.; Burmester, E.; Babaian, E.; Weiss, H.D.; Hohlbach, G.

    1984-01-01

    In 58 patients with lesions of the vertebral column in the thoracal and lumbar section established by conventional X-ray, the informative power of computerized tomography was tested. Axial projection with the superimposition-free presentation of bone and soft-tissue structures in the motional segment clears up the diagnostically decisive question of the extent of the lesion and form of fracture, and thus provides information on the stability or instability of the fracture relevant for the therapeutic action taken. All patients had compression fractures of vertebrae, with a fragment of the front edge broken away in 50 cases and one of the back edge broken away in 17 cases. In 30 cases the intervertebral disks were damaged. 43 fractures were stable, 25 were unstable. The instability of 13 fractures was only recognized by CT. In essence, the diagnostic action to be taken begins with a grand-survey X-ray in two planes as a screening, with computerized tomography following in the positive case. Conventional tomograms are not necessary. (BWU) [de

  4. Findings of psychopathology and computerized tomography in neuropsychiatric diseases

    International Nuclear Information System (INIS)

    Gross, G.; Huber, G.; Schuettler, R.

    1982-01-01

    1978-1980 we examined 451 patients of the Psychiatric University Clinic of Bonn by computerized tomography. From 260 patients with characterized diseases of the brain and brain damages 78 patients had neuropsychiatric diseases of old age, i.e. cerebro-vascular processes (average age of 63.7 years) and 9 patients had primary degenerative processes of the brain (average age of 62.1 years). Patients with diseases of the cerebral vessels showed irreversible psychopathological syndromes in 87%. The rate of pathological findings in CT increases in relation to degree of severity of the chronic (irreversible) organic psychosyndromes from 76% in pseudoneurasthenics syndromes to 93% in patients with organic changes of personality and to 100% in patients with dementia. The ambiguity of the conception of the multi-infarct-dementia is discussed. Only 19% of the sample with irreversible psychopathological changes showed localized neurological deficits and infarctions in CT, but none of them more than one. In all patients with dementia a cortical atrophy was found. There is a significant positive correlation between cerebral atrophy in CT and irreversible organic psychosyndrome. These findings with computerized tomography demonstrate in accordance with earlier pneumoencephalographic findings that distinct types of irreversible psychosyndromes can be correlated to distinct types of cerebral atrophy. But these statistical correlations between the degree of the severity of the loss of psychic functions and the reduction of cerebral tissue are not necessarily valid for any single case. (orig.) [de

  5. Density evaluation by computerized tomography in plain soils over different manipulation systems

    International Nuclear Information System (INIS)

    Pedrotti, Alceu

    1996-08-01

    The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic

  6. Cone beam computerized tomography of face. Technological assessment report

    International Nuclear Information System (INIS)

    Saint-Pierre, Francoise; Fanelli, Gaelle; Mosnegutu, Lavinia; Devaux, Frederique

    2009-12-01

    Cone beam computerized tomography is an imagery technique notably used for the maxillofacial complex or a complete or limited exploration of maxillo-mandibular and dento-alveolar structures. Typically, this technique is implemented with devices which are different from scanners in various respects (performance of several linear cuts, use of an open cone beam). Based on a literature survey, this document reports an assessment which aimed at determining technical and dosimetric performances of the device, potential benefits in terms of diagnosis and therapy with respect to existing imagery techniques, specifications and role of this technique in odonto-stomatology, maxillofacial surgery, and even in ENT, and operation conditions and training to perform this act

  7. Radiation protection in computerized tomography diagnostics; Strahlenschutz in der Computertomografie

    Energy Technology Data Exchange (ETDEWEB)

    Grust, Andreas [Radiologie am Hauptbahnhof, Duesseldorf (Germany)

    2012-11-01

    The essential advantage of computerized tomography (CT) compared to projecting radiographic techniques is the display of organs free of superposition using a 3D data set and additional enhanced contrast resolution. CT is a mostly objective and examination-independent technique that has developed towards an indispensable tool for tumor diagnostics and traumatology. With respect to the total amount of X-ray diagnostic examinations CT is a rather seldom used technique, nevertheless causing a disproportionately high amount of the collective effective dose of the German population. This disadvantage triggers the necessity to work on a radiation dose reduction. The author discusses the issues X-ray tube current reduction, layer thickness, pitch factor, scan length, dose modulation, adaptive collimation, and iterative reconstruction.

  8. Computerized tomography in evaluation of decreased acetabular and femoral anteversion

    International Nuclear Information System (INIS)

    Toennis, D.; Skamel, H.J.

    2003-01-01

    Computerized tomography has received a new importance. It has been shown that decreased anteversion of femur and acetabulum, when both have decreased angles, are causing pain and osteoarthritis of the hip joint. Operative treatment should be performed before osteoarthritis develops. Exact measurements therefore are necessary. The investigation should be performed in prone position to have the pelvis lying in a defined and normal position. Femoral torsion is measured between the transverse axis of the knee and the femoral neck. The transverse axis for measurement of the femoral anteversion is defined by a rectangular line to the sagittal plane. For evaluation of the femoral anteversion in total the angle of the condyles has to be added to the femoral neck angle when the knee is found in internal rotation. Acetabular anteversion should be measured at the level where the femoral head is still in full contact and congruence with the anterior margin of the acetabulum. (orig.) [de

  9. Computerized tomography in diagnosis of parasitic hepatic lesions

    International Nuclear Information System (INIS)

    Filimonov, G.P.; Garibashvili, R.N.; Tumol'skaya, N.I.

    1984-01-01

    An attempt has been made to estimate the diagnostic importance of computerized tomography (CT) in cases of hepatic echinococcosis and alveococcosis to outline the semiotics of these lesions and to establish an order of using CT in a general diagnostic complex. 73 patients at the age of 15-70 (49 with echinococcosis, 24-alveococcosis) have been supervised. The analysis of the results of clinical CT application in cases of parasitic hepatic lesions has shown that CT permits not only to reveal parasitic nodes up to 2 cm size in the liver and other organs but give also their topographoanatomic characteristic. By means of CT one can determine interrelations of parasitic formation with vessels and hepatic bileducts, vena cava inferior, other organs. One can judge at the same time on their compression and germination, remote echinococcosis residues, other complications

  10. Importance of computerized tomography for surgical treatment of intracranial hematomas

    International Nuclear Information System (INIS)

    Diemath, H.E.

    1982-01-01

    The improved treatment by using computerized tomography (CT) located operating theater and intensive care unit is reported in comparison of 3,382 patients with severe head injuries. By preoperative use of CT the frequency of diagnosed hermatomas was about the same (29.5% before CT; 27.0% with CT) but the preoperative diagnosed multiple hematomas were much more frequent (14.0% resp. 27.0%). The most important advantage however is the saving of time by CT in this localisation by which the chance of survival has increased from 54% to 69%. Without any doubt everywhere in neurotraumatology the CT should be situated as near as possible to the intensive care unit and to the operating theater and should be available 24 hours a day. (Author) [de

  11. Contribution of computerized tomography to diagnosis of congenital toxoplasmosis

    International Nuclear Information System (INIS)

    Kouba, K.; Kalvach, P.; Nevarilova, A.; Stankova, M.

    1986-01-01

    Computerized tomography (CT) of the brain in 20 patients (age 6 to 20 years) with the ocular form of toxoplasmosis and various damage of the CNS revealed that in 8 patients intracranial calcifications were present while no calcifications were found on the X-ray of the skull. On the CT also other pathological findings were detected in the brain apart from calcifications. (Similarly as in 25% of the AIDS syndrome where affections of the CNS are not yet known.) Based on the authors'experience and data from abroad, CT examination of the brain can be recommended as very useful for the confirmation of the diagnosis of congenital toxoplasmosis also with regard to the prognosis of further psychomotoric development of the child. (author). 2 tabs., 7 refs

  12. Computerized tomography using water to render the gastrointestinal tract opaque

    International Nuclear Information System (INIS)

    Gaa, J.; Deininger, H.K.; Georgi, M.

    1993-01-01

    An account is given of the technical procedure and results of computerized tomography in the examination of various gastrointestinal disorders using water as an oral and rectal contrast medium. The experience gained so far points to the fact that water as a contrast medium is mainly suitable in the preoperative staging of malignant gastric and colorectal tumours. The rectal injection of water further appears to be favourable in investigations for recidivation following deep anterior resection without impairment of the excretory functions. Our own results were contrary to the findings of other authors in that we had no difficulty in visualizing distal sections of the small intestine in patients suffering from Crohn's disease. The use of water as a contrast medium can, however, not be recommended in the presence of intra-abdominal abscesses, ascites or cystic tumours, as such changes cannot clearly be differentiated from intestinal loops filled with water. (orig./MG) [de

  13. Computerized axial tomography in the detection of brain damage

    International Nuclear Information System (INIS)

    Cala, L.A.; Mastaglia, F.L.

    1980-01-01

    The cranial computerized axial tomography (CAT) findings in groups of patients with epilepsy, migraine, hypertension, and other general medical disorders have been reviewed to assess the frequency and patterns of focal and diffuse brain damage. In addition to demonstrating focal lesions in a proportion of patients with seizures and in patients presenting with a stroke, the CAT scan showed a premature degree of cerebral atrophy in an appreciable proportion of patients with long-standing epilepsy, hypertension and diabetes, and in some patients with migraine, valvular and ischaemic heart disease, chronic obstructive airways disease, and chronic renal failure. The value of CAT as a means of screening for brain damage in groups of individuals at risk is discussed

  14. Computerized tomography-guided neurolytic splanchnic nerve block

    International Nuclear Information System (INIS)

    Henriquet, Franco; De Martini, Giuseppe; Roy, Maria Teresa; Pretrolesi, Fabio; Martinoli, Carlo; Cariati, Maurizio; Fiorentini, Franco.

    1997-01-01

    Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celia anatomy and complicate the percutaneous block of the celiac plexus. Endosulfan, Malathion and Methyl parathion, on the metabolic rate of the estuarine clam, Villorita cyprinoides var. cochinensis, have been investigated. The animals exposed to the lower sublethal concentrations of Endosulfan, Malthion and Methyl parathion consumed oxygen at the rate of 1.60, 1.98 and 2.09 ml. 0 2 g - 1 h -1 respectively, while at the higher concentrations of the pesticides, consumption of oxygen by the animal dropped to nearly half the control value. When compared to Malathion and Methyl parathion. Endosulfan induced animals recorded a greater reduction in her percentage deviation (from control) of oxygen consumption, possibly due to hypoxia induced by the pollutants

  15. Non-Conventional Applications of Computerized Tomography: Analysis of Solid Dosage Forms Produced by Pharmaceutical Industry

    International Nuclear Information System (INIS)

    Martins de Oliveira, Jose Jr.; Germano Martins, Antonio Cesar

    2010-01-01

    X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe a non-conventional application of computerized tomography: visualization and improvements in the understanding of some internal structural features of solid dosage forms. A micro-CT X-ray scanner, with a minimum resolution of 30 μm was used to characterize some pharmaceutical tablets, granules, controlled-release osmotic tablet and liquid-filled soft-gelatin capsules. The analysis presented in this work are essentially qualitative, but quantitative parameters, such as porosity, density distribution, tablets dimensions, etc. could also be obtained using the related CT techniques.

  16. Anatomic radiological study of transverse diameter of abdominal aorta by computerized tomography

    International Nuclear Information System (INIS)

    Ures, S.

    1984-01-01

    The transverse diameter of abdominal aorta by computerized tomography is studied. The purpose is establish the frequent standard diameters and then diagnose early pathologies, mainly aneurisms. (M.A.C.) [pt

  17. Two cases of posterior scleritis and findings of computerized tomography and ultrasonography

    International Nuclear Information System (INIS)

    Ohara, Takakazu; Uji, Yukitaka; Fujioka, Chieko; Mori, Kazuma

    1982-01-01

    Two cases of unilateral posterior scleritis, seen in 56-year-old and 68-year-old females, are reported. Computerized tomography showed characteristic findings, as follows: 1) Thickening of the posterior sclera and surrounding tissue. 2) Irregularity of the posterior wall of the eyeball. 3) Increased radiographic density in the posterior wall of the eyeball. Ultrasonography also suggested thickening of the posterior sclera. Computerized tomography and ultrasonography are considered useful in the diagnosis of posterior scleritis. (author)

  18. Computerized tomography data on CNS affection in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Ivanova, M.M.; Bliznyuk, O.I.; Todua, F.I.; Tumanova, A.A.

    1989-01-01

    Computed tomography (CT) of the brain was employed in 40 patients with systemic lupus erythematosus (SLE). Clinical cerebral pathology was obvious in 30 and absent in 10 patients. By CT cerebral symptoms were divided of 4 groups. Clinical symptom complexes of CNS defects and SLE were reflected on definite CT images correlated with focal damage to the brain. CT picture of enlarged subarachnoid space, ventricles and basal cisterns can be observed in SLE patients without neurological symptoms. This indicated likely subclinical cerebral affection

  19. Computerized tomography of the traumatic hematoma in the corpus callosum

    International Nuclear Information System (INIS)

    Ogura, Koichiro; Yamamoto, Isao; Hara, Makoto; Suzuki, Yoshio; Nakane, Toshichi; Watanabe, Masao.

    1982-01-01

    The value of the computerized tomography (CT) in the diagnosis of the intracerebral hematoma has been well documented. However, there is little report about the CT findings of the hematoma of the corpus callosum. This report presents two cases of the traumatic hematoma in the corpus callosum and is discussed about their CT findings. Two patients, 52 year-old male and 40 year-old male, respectively, are the cases of blunt mechanical head trauma which were accompanied neither by skull fracture nor by scalp injury. In all these cases, the findings that hematoma occupied from the genu to the body of the corpus callosum were verified by surgery and the axial CT revealed the following two similar findings. First; the hematoma in the genu of the corpus callosum was shown as a cresent-shaped high density mass. This finding seems to be due to the following anatomical structure, that is, the genu of the corpus callosum is located just in front of the anterior horn of the lateral ventricles in the shape of the convex towards posteriorly. Second; as the midportion of the body of the corpus callosum tends to be appeared narrow in width between both lateral ventricles, the hematoma which extended from the genu towards the body of the corpus callosum was shown as a dumbbell-shaped high density mass. (author)

  20. Computerized tomography of renal parenchymal disturbance following nephrolithotomy

    International Nuclear Information System (INIS)

    Fukuoka, Hiroshi; Ishizuka, Eiichi; Fukushima, Shuji.

    1983-01-01

    Staghorn calculi were removed by nephrolithotomy with the one-layer interrupted parenchymal suture method designed by Taguchi and renal parenchymal disturbance following the operation were evaluated by computerized tomography. Twenty kidneys in 17 cases were examined pre and postoperatively for changes in the incised and sutured part of the renal parenchyma. The postoperative CT scanning demonstrated the low density areas following enhancement and depression of the parenchyma. These changes were classified into the following 3 patterns: Type I-no changes were observed in the parenchyma, or a linear low density area was found (5 kidneys, 25.0%); type II-a long, narrow strip of low density area was found in accord with the excised and sutured part (5 kidneys, 25.0%); and type III-a wedge-shaped low density area or depression of the parenchyma was found (10 kidneys, 50.0%). The length of the parenchymal incision was analysed with reference to these patterns. The length of type I was significantly shorter than that of type II or III (p<0.05). Th e clamping time of the renal pedicle in type I was also shorter than that in type II and III, but the differences did not reach a statistically significant level. Type II pattern frequently was found shortly after the operation. It is, however, undeniable that type II may tramsform to type III. (J.P.N.)

  1. Possible application of computerized tomography and ultrasonography in diagnosing hyperparathyroidism

    International Nuclear Information System (INIS)

    Sotornik, I.; Sobota, J.; Kocandrle, V.; Drab, K.; Klima, J.; Zastava, V.; Mrhova, O.

    1985-01-01

    Initial experience is reported with the application of computerized tomography (CT) in the diagnosis of enlarged parathyroid glands in 19 patients with chronic renal failure who developed renal osteopathy in the course of hemodialysis treatment; in one patient an adenoma of the parathyroid associated with primary hyperparathyroidism was revealed. In the group of patients CT revealed enlarged parathyroid glands 14 times including 7 patients subjected to surgery of the parathyroid where the CT finding was confirmed in all instances. In patients with CT confirmed enlargement of the parathyroid glands, significantly higher levels of the bone isoenzyme ALP (p<0.05), total ACP (p<0.01), OH-proline in the blood (p<0.01) and C-terminal PTH (p<0.01) were found along with an advanced X-ray finding of hyperparathyroidism, as compared with patients with negative CT result. CT examination is a valuable noninvasive method which, together with the mentioned biochemical and X-ray findings, contributes in a fundamental way to the decision on whether surgery of the parathyroid glands should be undertaken. It is believed that at present it is difficult to provide evidence of enlarged parathyroids by means of sonographic examinations and the method calls for further investigation. (author)

  2. Percutaneous nephrolithotomy in pediatric patients: is computerized tomography a must?

    Science.gov (United States)

    Gedik, Abdullah; Tutus, Ali; Kayan, Devrim; Yılmaz, Yakup; Bircan, Kamuran

    2011-02-01

    The aim of this study was to retrospectively evaluate the results of pediatric percutaneous nephrolithotomy (PNL) cases, and discuss the results and necessity of non-contrast computerized tomography (CT) in these cases. In all, 48 pediatric patients who underwent PNL were retrospectively evaluated. Before PNL, either intravenous urography or CT was performed. In all patients, we evaluated the PNL time, scopy time with stone burden, and complications. During the PNL procedure, we switched to open surgery in two cases: in one because of renal pelvis perforation and in the other because of transcolonic access. In one patient who was scheduled to undergo PNL, we performed open surgery, primarily because we detected a retrorenal colon with CT. The stone burden in 45 patients who underwent PNL was 445 ± 225 mm(2), the PNL time was 51 ± 23 min, and the scopy time was 6.1 ± 2.7 min. We removed nephrostomy tubes 1-4 days after the procedure. In two patients, 24 h after removal of nephrostomy tubes, we inserted double J stents because of prolonged urine extravasation from the tract. In all, 34 of the 45 patients were stone-free, 5 patients had clinically insignificant stone fragments, and 6 patients had residual stones. PNL is a safe and effective method in the treatment of pediatric patients with kidney stones. Clinical experience is the most important factor in obtaining stone-free results. CT should be performed in all pediatric patients in order to prevent colon perforation.

  3. Evaluation of the soil-seed environment through computerized tomography

    International Nuclear Information System (INIS)

    Modolo, Alcir Jose; Fernandes, Haroldo Carlos; Schaefer, Carlos Ernesto G.R.; Santos, Nerilson Terra; Silveira, Joao Cleber Modernel da

    2008-01-01

    The physical conditioning of the soil around seeds is of great importance for an adequate initial development of a crop, ensuring a healthy plant population. A suitable soil-seed contact is a prerequisite for a fast crop germination and good establishment. In this study, computerized tomography of millimeter resolution was used to determine the soil-seed environment in a no tillage system, immediately after soybean planting. A split plot design was used, in which the plots consisted of three contents of soil water, corresponding to 0.27; 0,31 and 0.36 kg kg -1 , respectively, and the split plots of four load levels applied by the compaction wheel, corresponding to 0, 50, 90 and 140 N, respectively. It was used a random block design, with four replications. The medium soil density in the seed area and the medium density profile in the sowing furrow were evaluated. According to the results, it may be concluded that: the loads applied by the compaction wheel increased soil density at the vertical planting level beneath planting depth as compared with values obtained before planting, and; the combination of wheel loads and soil water contents did not influence the mean soil density in the seed area. (author)

  4. Computerized tomography and prognosis in paediatric head injury

    International Nuclear Information System (INIS)

    Tomberg, T.; Rink, U.; Pikkoja, E.; Tikk, A.

    1996-01-01

    The authors have analysed the computerized tomography (CT) findings and their correlation with the clinical state, early and late outcome in children and adolescents with head injuries (HI). This study represents clinical and CT data of 82 consecutive HI patients under 18 years of age. Among them 51 (62%) were boys and 31 (38 %) girls. The application of CT to the evaluation of the morphologic manifestations of HI in children has shown some differences in forms and mechanisms of injury and in outcome compared to adults. In the paediatric HI the most frequent finding was diffuse brain swelling with CT evidence of ventricular and cisternal compression or obliteration. Prognostically the most unfavourable findings were shearing injury, intracerebral and subdural haematomas combined with brain swelling and parenchymal damage. According to the Lidcombe impairment scale, outcome from severe paediatric HI was determined in the 3rd and 6th months, one year and 2 years after the injury. The outcome two years after severe HI varied to a great extent and was better in children than in adults. Although there was long-term disruption of the patient's quality of life, our data show that as there are no predictors of individual outcomes in child HI, no child should be excluded from early and long-term rehabilitation. (author)

  5. Evaluation of Biomaterials Using Micro-Computerized Tomography

    International Nuclear Information System (INIS)

    Torris, A. T. Arun; Columbus, K. C. Soumya; Saaj, U. S.; Krishnan, Kalliyana V.; Nair, Manitha B.

    2008-01-01

    Micro-computed tomography or Micro-CT is a high resolution, non-invasive, x-ray scanning technique that allows precise three-dimensional imaging and quantification of micro-architectural and structural parameters of objects. Tomographic reconstruction is based on a cone-beam convolution-back-projection algorithm. Micro-architectural and structural parameters such as porosity, surface area to volume ratio, interconnectivity, pore size, wall thickness, anisotropy and cross-section area of biomaterials and bio-specimens such as trabecular bone, polymer scaffold, bio-ceramics and dental restorative were evaluated through imaging and computer aided manipulation of the object scan data sets.

  6. Prediction of traumatic avascular necrosis of the femoral head by single photon emission computerized tomography and computerized tomography: an experimental study in dogs

    Directory of Open Access Journals (Sweden)

    SHEN Feng

    2012-02-01

    Full Text Available 【Abstract】 Objective: To evaluate the femoral head perfusion and to predict the traumatic avascular necrosis (AVN of the femoral head by single photon emission computerized tomography and computerized tomography (SPECT/CT. Methods: Totally 18 adult beagle dogs were divided randomly into three equal-sized (n=6 groups. Subsequently different degrees of ischemia model were developed by destroying blood vessels of the femoral head. The left hip received sham operation as normal control and the right hip underwent blood interruption. In Group A, the ligamentum teres was cut off. In Group B, the marrow cavity of the right femoral neck was destroyed while in Group C, the soft tissues at the base of the femoral neck were stripped in addition to the resection of the ligamentum teres and destruction of the marrow cavity. Three hours after surgery, SPECT/CT was performed. Laser Doppler Flowmetry (LDF measurements were also obtained at three different time points (before operation, immediately and three hours after operation in order to assess the change process of blood supply to the femoral head. Results: SPECT/CT showed no significant difference in the radionuclide uptake between the right and left femoral heads in Group A (t=-0.09, P=0.94 and Group B (t= 0.52, P=0.62. However, in Group C, it was 261±62 for the right femoral head, only 12% of that in the left femoral head. LDF measurements indicated that the femoral head perfusion was decreased from (45.0±3.3 PU to (39.1±3.7 PU in Group A, from (44.0±2.7 PU to (34.3±2.6 PU in Group B, and from (47.3±2.1 PU to (4.96±0.6 PU in Group C immediately after operation. However, the perfusion was restored and returned to normal values three hours after operation except in Group C. Conclusion: SPECT/CT could assess the perfusion of the femoral head semiquantitatively, which might be useful in predicting the development of traumatic AVN. Key words: Femur head necrosis; Femoral head; Tomography, emission

  7. Proposal for dose measurement in the crystalline lens and thyroid in computerized tomography of paranasal sinuses

    International Nuclear Information System (INIS)

    Mello, Ana Caroline; Machado Neto, Vicente

    2014-01-01

    With the evolution of diagnostic imaging equipment, a computerized tomography (CT) has become one of the most used tests to assess pathologies affecting the paranasal sinuses. This work aims at presenting a method of obtaining measurements of dose in the eye lenses and thyroid, from the execution of CT of the paranasal sinuses protocol. Experimental procedure will be used in an object simulator (phantom) head and neck made with accessible materials and thermoluminescent dosimeters (TLDs) of LiF: Mg,Ti for the absorbed dose in the regions of interest, when exposed to radiation in a CT scanner 16 channels. After the dosimetric evaluation with phantom use, this methodology will be applied in vivo, or in patients with medical request for the examination and approval by the Ethics Committee. Thus, at the end of this survey protocols and actions aimed at reducing the absorbed dose in the eye lenses and thyroid without impairing the diagnostic image quality can be proposed. (author)

  8. Value of the computerized axial tomography for early diagnosis of cranio cerebral trauma

    International Nuclear Information System (INIS)

    Rodriguez Cheong, Maricel; Dosouto Infante, Vivian; Rosales Fargie, Yamile

    2010-01-01

    A descriptive and cross-sectional study was conducted in 62 patients with cranio cerebral trauma admitted to 'Saturnino Lora' Provincial Teaching Hospital of Santiago de Cuba, from January 2005 to May 2006, in whom computerized axial tomography indicated at the emergency room was performed with the purpose of evaluating the effectiveness of this radiographic technique for early diagnosis of the injury. In the case material there was neither association between the source and imaging results, nor between the age and sex. The main clinical manifestations were vomiting, headache and motor deficit as well as frontal location, intraparenchymatous hematoma (the latter as the most common image finding) and the hyperdense area as tomographic pattern. The survival was of 91,9%

  9. Detection of lymph node metastasis in patients with nodal prostate cancer relapse using (18)F/(11)C-choline positron emission tomography/computerized tomography.

    Science.gov (United States)

    Jilg, Cordula A; Schultze-Seemann, Wolfgang; Drendel, Vanessa; Vach, Werner; Wieser, Gesche; Krauss, Tobias; Jandausch, Anett; Hölz, Stefanie; Henne, Karl; Reske, Sven N; Grosu, Anca-L; Weber, Wolfgang A; Rischke, H Christian

    2014-07-01

    We evaluated the diagnostic accuracy of choline positron emission tomography/computerized tomography for nodal relapse of prostate cancer according to topographical site and tumor infiltration size in lymph nodes. A total of 72 patients with nodal prostate cancer relapse after primary therapy underwent pelvic and/or retroperitoneal salvage lymph node dissection. Salvage was done after whole body positron emission tomography/computerized tomography with (11)C-choline or (18)F-fluoroethylcholine showed positron emission tomography positive lymph nodes but no other detectable metastasis. Diagnostic accuracy was evaluated in 160 dissected lymph node regions (pelvic left/right and retroperitoneal), 498 subregions (common, external and internal iliac, obturator, presacral, aortic bifurcation, aortal, vena caval and interaortocaval) and 2,122 lymph nodes. Lymph node metastasis was present in 32% of resected lymph nodes (681 of 2,122), resulting in 238 positive subregions and 111 positive regions. Positron emission tomography/computerized tomography was positive for 110 regions and 209 subregions. Sensitivity, specificity, positive and negative predictive values, and accuracy were 91.9%, 83.7%, 92.7%, 82.0% and 89.4% (region based), 80.7%, 93.5%, 91.9%, 84.1% and 87.3% (subregion based), and 57.0%, 98.4%, 94.5%, 82.6% and 84.9% (lesion based), respectively. Of 393 positive lymph node metastases detected by this method 278 (70.7%) were in lymph nodes with a less than 10 mm short axis diameter. Imaging sensitivity was 13.3%, 57.4% and 82.8% for a tumor infiltration depth of 2 or greater to less than 3 mm, 5 or greater to less than 6 mm and 10 or greater to less than 11 mm, respectively. Lymph node metastasis site and the radiotracer ((11)C-choline/(18)F-fluoroethylcholine) had no substantial impact on diagnostic accuracy. Choline positron emission tomography/computerized tomography detects affected lymph node regions (pelvic left/right and retroperitoneal) in patients with

  10. Measurement and analysis of noise power spectrum of computerized tomography in images; Medida y analysis del espectro de potencias del ruido en imagenes de tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Castro Tejero, P.; Garayoa Roca, J.

    2013-07-01

    This paper examines the implementation of the spectrum of powers of the noise, NPS, as metric to characterize the noise, both in magnitude and in texture, for CT scans. The NPS found show that you for convolution filters that assume a greater softening in the reconstructed image, spectrum is concentrated in the low frequencies, while for filters sharp, the spectrum extends to high frequencies. In the analyzed cases, there is a low frequency component, largely due to the structure-borne noise, which can be a potential negative effect on the detectability of injuries. (Author)

  11. Principles of medical imaging with emphasis on tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kouris, K [Institute of Nuclear Medicine, University College, London Medical School, Mortimer Street, London W1N 8AA (United Kingdom)

    1994-12-31

    Medical imaging with ionizing and non-ionizing radiations belongs to the class of problems known as indirect sensing. This article is concerned with imaging methods known as image reconstruction from projections or computerized tomography. A brief comparative study of the theory is presented. Depending on the nature and modes of propagation of the employed radiation, methods are discussed either under transmission tomography (with gamma rays and X rays) or emission tomography (with gamma rays and positrons). Magnetic resonance Imaging (MRI) is described as resonant absorption and re-emission of radiofrequency energy. (author). 6 refs, 1 fig.

  12. Computerized tomography findings of acute traumatic epidural hematoma

    International Nuclear Information System (INIS)

    Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Yajima, Kouzo; Yano, Masami; Otsuka, Toshibumi

    1984-01-01

    During four year period from April, 1977 to March, 1981, 53 cases with acute traumatic epidural hematoma had been encountered out of 430 acute head injured patients examined by computerized tomography (CT) within 24 hours after incurring the trauma. Besides the initial CT, the authors performed contrast enhanced CT (41 cases) and serial CT scanning (31 cases). There were 49 cases of epidural hematoma existing in the supratentorial region, Two cases infratentorial region and 2 cases in the both regions. Two cases of vertex epidural hematoma had been encountered, one of them required vertical scan technique. In 22 (41%) of the 53 patients, the initial CT showed evidence of other cerebral lesions. The most frequent lesion was pneumocephalus (11 cases), 3 cases of them existed in the epidural hematoma. There were also intracerebral hematoma (6 cases), subdural hematoma (4 cases), cerebral contusion (2 cases), intraventricular hemorrhage (2 cases) and 2 cases of them demonstrated ''diffuse traumatic cerebral injury''. During contrast enhanced CT, 11 cases out of 41 cases indicated several enhancement pattern. There were total enhancement of epidural hematoma (2 cases), partial enhancement of hematoma (2 cases) and enhancement of internal margin of hematoma (2 cases). Serial CT scans was performed in 36 out of the 53 patients. Common findings on the serial CT scans were decreased density collection in the subdural space such as subdural effusions or chronic subdural hematomas (8 cases) and enlargement of small epidural hematomas (3 cases). After evacuation of epidural hematoma, there were some cases showing the so-called ''delayed traumatic intracerebral hematoma'' (4 cases), appearance of other epidural hematoma (1 case) and development of small cerebral infarction in the basal ganglia. There was one case indicating appearance of a new epidural hematoma contra lateral to the side of evacuation of subdural hematoma. (J.P.N.)

  13. Clinical value of computerized tomography scanning in severe head injury

    International Nuclear Information System (INIS)

    Kobayashi, Shiro; Yano, Masami; Otsuka, Toshibumi; Nakazawa, Shozo

    1982-01-01

    Serial computerized tomography (SCT) was performed on 138 patients suffering from severe head injuries (8 or less on the Glasgow Coma Scale). Standard practice called for scans to be done upon admission (within hours of the injury), and after 1, 3, 7 days and 1 month. Subsequent CT's depended on the patient's condition. Clinical results at the time of discharge were graded according to the Glasgow Outcome Scale. Patients who died, were in a persistent vegetative state, or were severely disabled were considered to have a ''bad outcome''. On the other hand, patients who were somewhat disabled or made good recoveries were considered to have a ''good outcome''. During the serial CT scan, there were new findings (not visualized on the initial CT but appearing on subsequent ones) in 91 of the 138 patients. These new findings were classified as follows; 1) decreased density collection in the subdural space (DDC), 2) ventricular dilation (VD), 3) intracerebral hematoma (ICH), 4) intraventricular hemorrhage (IVH), 5) extracerebral hematoma (ECH), 6) edema (E), 7) infarction (I). We defined ICH, IVH, ECH, E and I as new lesions. Of the 60 patients with new lesions 12 had good outcomes and 48 had poor outcomes. There were 78 patients who did not have any new lesions, 60 with good outcomes and 18 with poor outcomes. A significant correlation was found between good outcomes and the absence of new lesions, and between bad outcomes and the development of new lesions (p 2 = 44.038). We conclude that SCT can help predict the outcome with severe head injury patients and may be very important in their examination and care. (J.P.N.)

  14. What does the psychiatrist expect as to computerized tomography

    International Nuclear Information System (INIS)

    Huber, G.

    1980-01-01

    The computerized tomography (CT) can be applied also in psychiatry as an instrument of basic research. The problem of normative data as visualized by CT-scanning is up to now not yet satisfactory solved. Faulty appreciations especially on the cebral cortex in the sense of false-positive findings with possible serious social consequences are frequently. For judging of brain cortex as to atrophy primarily more basically situated sulci in various slices are taken into consideration, while the sulci of upper slices near the vertex just as the representations of cisterns, the interhemispheric fissure and Pacchionian granulations should not to be evaluated. On a new revision of the subject cerebral atrophy and irreversible psychosyndrome it is necessary and useful to compare the results of CT-scanning with those of pneumoencephalographic studies. The favourable possibilities which the CT offers also for diagnostic and research in psychiatry are to be used by critical appreciation of already existing experiences. The indication fpr TC requires complete psychiatric-neurological investigation. The interpretation of findings and the attempts to correlate them with the clinical data must take place in close cooperation with the clinical psychiatry. The neuroradiological evidence of cerebral atrophy can give hints concerning the diagnosis and prognosis only in connection with all clinical data. Findings of cerebral atrophy, combined cortical and subcortical, exclusively subcortical of preferably on the 3rd ventricle are non-specific and not characteristic of a certain disease. There are only correlations between certain types of cerebral atrophy and certain types of irreversible psychopathological syndromes. (orig.) [de

  15. Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors.

    Science.gov (United States)

    Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

    2017-04-05

    Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and -1.716 for liver, -0.153 and -1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P> 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = -8.11 for liver, -7.83 for pancreas, and -5.38 for renal cortex, all P 3, indicating clinically acceptable image quality. Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

  16. Computerized tomography of chest in emphysema and interstitial diseases diagnosis

    International Nuclear Information System (INIS)

    Souto Bayarri, M.; Malagari, K.; Ibarburen, C.; Arenas, G.; Correa Pombo, J.; Garcia Tahoces, P.; Tucker, D.; Barnes, G.T.; Luna, R.; Zerhouni, E.A.; Fraser, R.G.; Vidal Carrerira, J.J.

    1994-01-01

    To study the effect of increasing the spatial resolution on thin section (1.5 mm) computed tomography (CT) of the chest, we compared images reconstructed with the standard algorithm (SA) to three other images obtained with 1) a high spatial frequency algorithm, 2) retrospective targeting to a small field of view (FOV) reconstructed with the high spatial frequency algorithm, and 3) the same high spatial frequency algorithm with images acquired with the small (0.6 mm) rather the large (0.9 mm) focal spot. Examinations were performed on a phantom, on normal subjects, and on patients with emphysema and other diffuse lung diseases. Modulation transfer function (MTF) calculations revealed that higher resolution was achieved on the small focal spot and high spatial frequency algorithm than on the standard algorithm. Evaluation of the four images from 25 normal subjects, 16 patients with emphysema and 9 with interstitial disease was performed by means of an ROC study. Results from the areas under the ROC curves, sensitivity and specificity have shown that images reconstructed with the high spatial frequency algorithm were preferred. We conclude that the use of a high spatial frequency algorithm increases spatial resolution and improves visibility of lung parenchyma. Although more evaluation is needed, the potential of increasing spatial resolution further by using a smaller focal spot is currently limited by the mas Available per slice and the associated increased level of quantum noise. (Author)

  17. Epiploic appendicitis and omental infarction. Findings in the ultrasonography and computerized tomography

    International Nuclear Information System (INIS)

    Migule, A.; Ripolles, T.; Martinez, M. J.; Morote, V.; Ruiz, A.

    2001-01-01

    Describe the findings in the ultrasonography and computerized tomography (CT) of the omental infarction and epiploic appendicitis. The clinical and radiological findings of the patients diagnosed in our hospital with epiploic appendicitis or omental infarctions between August 1994 and March 2001 were assessed retrospectively. We found a high incidence (42 cases) of these two diseases: 30 patients with diagnosis of epiploic appendicitis and 12 with the diagnosis of omental infarction. Four patients were treated surgically, while the remaining 38 were conservatively, without posterior complications. The ultrasonography and CT images is characteristics. making it possible to make a diagnosis of epiploic appendicitis or omental infarction with certainty. It is not necessary to make a differential diagnosis between the two entities because their prognosis and treatment are similar. Their incidence is much more frequent than that previously published. (Author) 19 refs

  18. Materials testing by computerized tomography with neutrons and gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghobary, A M; Bakkoush, F A; Megahid, R M [Reactor and Neutron Physics Department, Nuclear Research Center, A.E.A., Cairo (Egypt)

    1997-12-31

    The method of computerized tomography by fast neutrons and gamma-rays are used for inspecting and testing of materials by non-destructive technique. The transmission technique was applied using narrow collimated beams of reactor neutrons and gamma-ray. The neutron and gamma-rays transmitted through the object inspection were measured by means of a neutron gamma detector with Ne - 213 liquid organic scintillator. The undesired pulses of neutrons or gamma-rays are rejected from the transmitted beam by a discrimination technique based on the difference in the decay part of light pulse produced by recoil electrons or recoil protons. The transmitted neutrons or gamma-rays for different projections used to get the image of the section through the object investigated using the method of filtered back projection (FBP) algorithm. 8 figs.

  19. Characterization of filters and filtration process using X-ray computerized tomography

    International Nuclear Information System (INIS)

    Maschio, Celio; Arruda, Antonio Celso Fonseca de

    1999-01-01

    The objective of this work is to present the potential of X-Ray computerized tomography as a tool for internal characterization of filters used in the solid-liquid separation, mainly the water filters. Cartridge filters (for industrial and domestic applications) contaminated with glass beads were used. The scanning process was carried out both with and without contaminant in the filter to compare the attenuation coefficient of the clean filter and the contaminated filter. The images showed that is possible the mapping the internal structure of the filters and the distribution of the contaminant, permitting a local analysis, that is not possible through the standard tests used by the manufactures. These standard tests reveal only global characteristics of the filter media. The possibility of application for manufacturing process control was also shown, because the non invasive nature is a important advantage of the technique, which also permitted damage detection in filters submitted to severe operational conditions. (author)

  20. Development of direct observation aparatus of coal carbonization process by x-ray computerized tomography method

    International Nuclear Information System (INIS)

    Sakawa, Mitsuhiro; Shiraishi, Katsuhiko; Sakurai, Yoshihisa; Shimomura, Yasuto

    1987-01-01

    Coke production by chamber ovens has a long history and efforts are being continued to make the manufacturing process efficient and to preserve the environment. In this production by this method, however, it is hardly possible to obtain direct information during coal carbonization. Since the elements that compose coal and coke are carbon, hydrogen, oxygen, etc. and are similar to those of the human body, authors has developed a coke oven that permits the direct observation of the coal carbonization process using a soft X-ray computerized tomography (CT) apparatus used in medical treatment. The following phenomena can be observed as images by the coke oven for the CT method : 1) Changes in the bulk density of charge coal (including the difference in the water content), 2) Width of the plastic layer and movement of the plastic layer in the coke oven chamber, 3) Expansion and shrinkage of the charge in the coke oven chamber, 4) Initiation and growth of cracks. (author)

  1. Image reconstruction. Application to transverse axial tomography

    International Nuclear Information System (INIS)

    Aubry, Florent.

    1977-09-01

    A method of computerized tridimensional image reconstruction from their projection, especially in the computerized transverse axial tomography is suggested. First, the different techniques actually developped and presented in the literature are analyzed. Then, the equipment used is briefly described. The reconstruction algorithm developped is presented. This algorithm is based on the convolution method, well adapted to the real conditions of exploitation. It is an extension of SHEPP and LOGAN's algorithm. A correction of the self absorption and of the detector's response is proposed. Finally, the first results obtained which are satisfactory are given. The simplicity of the method which does not need a too long computation time makes possible the implementation of the algorithm on a mini-computer [fr

  2. Efficiency of computerized tomography in comparison with other neuroradiological investigation methods

    International Nuclear Information System (INIS)

    Kretzschmar, H.

    1979-01-01

    Computerized tomography is considered to be a decisive and the most reliable investigation method for the diagnosis of cerebral tumors. The rate of detection of intracranial blastomas is over 90%. Supratentorial growths are more easy to prove than tumors at the posterior cranial fossa. In the group of patients examined, 97.3% of the cerebral tumors were confirmed by computerized tomography: 98.7% of these were located above the tentorium and 89.3% under the tentorium. But the diagnostic value of computerized tomography is not only due to the high growth detection rate but also to its informative power as regards the position of growths in relation to vital centres, the type of the blastomas and their space-occupying effect. Thus this investigation method permits to evaluate the complex ''space occupation'' at one glance. By the angiographic method cerebral growths are confirmed in 86% of the cases; 88.6% of these are located above the tentorium. (orig.) [de

  3. Acute renal failure following contrast injection for head computerized tomography in two patients with diabetic nephropathy

    International Nuclear Information System (INIS)

    Matsunaga, Hiroshi; Sando, Hiroyuki; Nunokawa, Tomoo; Murakami, Tooru; Miyakawa, Yuzo

    1981-01-01

    Two cases of diabetes mellitus with renal and retinal involvement developed acute renal failure after undergoing head computerized tomography. The first case was a 62-year-old male who had been diagnosed as having diabetes 25 years before. He had diabetic retinopathy of Scott IIIb. Before head computerized tomography, the serum BUN was 37 mg/dl, and creatinine was 4.1 mg/dl. Oliguria began immediately after the scanning and confinued for 48 hr. The serum levels of BUN and creatinine rose to 106 and 7.7 mg/dl, respectively. Case 2 was a 49-year-old male who had been diagnosed as having diabetes 15 years before. He showed Scott IIb and IV retinopathy. The BUN and creatinine levels in the serum were 32 and 2.3 mg/dl, respectively. After receiving head computerized tomography, he developed oliguria and remained oliguric for 48 hr. During that period, the serum levels of BUN and creatinin were elevated to 112 and 7.5 mg/dl, respectively. Fortunately, both of these patients recovered from the oliguria without resorting to hemodialysis. The iodine contrast medium routinely used for contrast enhancement in the head computerized tomography was implicated in the acute renal failure of these patients. Only elevn cases have so far been reported in the literature who developed acute renal failure following computerized tomography. In view of the three or four times greater dosis of iodine contrast medium employed in computerized tomography compared to intravenous pyelography, the acute incidence of such complications might be much higher. Among the thirteen cases including the two reported here, as many as eight were diabetic. It is well recongnized that the incidence of acute renal failure after intravenous pyelography is particularly high in cases of diabetic nephropathy. (author)

  4. Positron emission computerized tomography: a potential tool for in vivo quantitation of the distribution of radiopharmaceuticals

    International Nuclear Information System (INIS)

    Huebner, K.F.; King, P.; Gibbs, W.D.; Washburn, L.C.; Hayes, R.L.

    1981-01-01

    The principles and some of the difficulties in quantitative positron emission computerized tomography have been discussed. We have shown that randoms and scattered events are a major cause of noise and counting errors in positron emission computerized tomography. The noise has been identified as a convoluting process and a mathematical solution has been presented. Examples of phantom studies and in vivo measurements have demonstrated that the distribution of positron emitting radiopharmaceuticals can be quantitated with much improved accuracy using the deconvolution equation to remove undesired noise

  5. Computerized tomography of adrenal glands in the investigation of Cushing's syn

    International Nuclear Information System (INIS)

    Abucham Filho, J.; Albertotti, C.; Kater, C.E.; Vieira, J.G.H.; Chacra, A.R.

    1983-01-01

    Computerized tomography of the adrenal glands was performed in 10 patients with Cushing's syndrome using a G.E. 8800 CT/T Body Scanner. The tomographic findings of unilateral adrenal masses in 4 patients were confirmed by surgery. In the remaining 6 patients, computerized tomography did not identify any masses, and both glands were well visualized and showed normal shape. In these patients, measurement of the adrenal glands revealed both normal (n=1) and enlarged glands (n=5). The findings of adrenalectomy (n=4) or transphenoidal surgery and follow-up (n=2) established the diagnosis of adrenal phyperplasia in all patients. (Author) [pt

  6. Analysis of the of bones through 3D computerized tomography

    International Nuclear Information System (INIS)

    Lima, I.; Lopes, R.T.; Oliveira, L.F.; Alves, J.M.

    2009-01-01

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-μTC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-μTC is a powerful technique that can be used to analyze bone microstructures. (author)

  7. Positron transaxial emission tomograph with computerized image reconstruction

    International Nuclear Information System (INIS)

    Jatteau, Michel.

    1981-01-01

    This invention concerns a positron transaxial emission tomography apparatus with computerized image reconstruction, like those used in nuclear medicine for studying the metabolism of organs, in physiological examinations and as a diagnosis aid. The operation is based on the principle of the detection of photons emitted when the positrons are annihilated by impact with an electron. The appliance is mainly composed of: (a) - a set of gamma ray detectors distributed on a polygonal arrangement around the body area to be examined, (b) - circuits for amplifying the signals delivered by the gamma ray detectors, (c) - computers essentially comprising energy integration and discrimination circuits and provided at the output of the detectors for calculating and delivering, as from the amplified signals, information on the position and energy relative to each occurrence constituted by the detections of photons, (d) - time coincidence circuits for selecting by emission of detector validation signals, only those occurrences, among the ensemble of those detected, which effectively result from the annihilation of positrons inside the area examined, (e) - a data processing system [fr

  8. Regional myocardial perfusion assessed by N-13 labeled ammonia and positron emission computerized axial tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.J.; Huang, S.C.; Selin, C.E.; Kuhl, D.E.

    1978-01-01

    The usefulness of 13 NH 3 as an indicator of regional myocardial perfusion suitable for positron emission computerized axial tomography (PCT) has been suggested. However, the relationship between myocardial blood flow and uptake of 13 NH 3 has not been examined quantitatively. It was therefore the purpose of the current investigation to quantitate the relationship of myocardial 13 NH 3 tissue concentration to myocardial blood flow and to examine its suitability for PCT imaging. Twelve open chest dogs were studied. In 8 of the dogs 25 imaging procedures with 13 NH 3 and PCT were performed. In the remaining four dogs the relationship between flow and myocardial 13 NH 3 tissue concentration was assessed by in vitro techniques. The PCT technique provided high quality cross-sectional images of the distribution of 13 NH 3 in left ventricular myocardium. No significant redistribution of 13 NH 3 in myocardium occurred with time. Alterations in regional myocardial blood flow resulted in changes of the regional distribution of 13 NH 3 that were readily appreciated on the PCT images

  9. Three dimensional fracture aperture and porosity distribution using computerized tomography

    Science.gov (United States)

    Wenning, Q.; Madonna, C.; Joss, L.; Pini, R.

    2017-12-01

    A wide range of geologic processes and geo-engineered applications are governed by coupled hydromechanical properties in the subsurface. In geothermal energy reservoirs, quantifying the rate of heat transfer is directly linked with the transport properties of fractures, underscoring the importance of fracture aperture characterization for achieving optimal heat production. In this context, coupled core-flooding experiments with non-invasive imaging techniques (e.g., X-Ray Computed Tomography - X-Ray CT) provide a powerful method to make observations of these properties under representative geologic conditions. This study focuses on quantifying fracture aperture distribution in a fractured westerly granite core by using a recently developed calibration-free method [Huo et al., 2016]. Porosity is also estimated with the X-ray saturation technique using helium and krypton gases as saturating fluids, chosen for their high transmissibility and high CT contrast [e.g., Vega et al., 2014]. The westerly granite sample (diameter: 5 cm, length: 10 cm) with a single through-going rough-walled fracture was mounted in a high-pressure aluminum core-holder and placed inside a medical CT scanner for imaging. During scanning the pore fluid pressure was undrained and constant, and the confining pressure was regulated to have the desired effective pressure (0.5, 5, 7 and 10 MPa) under loading and unloading conditions. 3D reconstructions of the sample have been prepared in terms of fracture aperture and porosity at a maximum resolution of (0.24×0.24×1) mm3. Fracture aperture maps obtained independently using helium and krypton for the whole core depict a similar heterogeneous aperture field, which is also dependent on confining pressure. Estimates of the average hydraulic aperture from CT scans are in quantitative agreement with results from fluid flow experiments. However, the latter lack of the level of observational detail achieved through imaging, which further evidence the

  10. Analysis of the percentage voids of test and field specimens using computerized tomography

    International Nuclear Information System (INIS)

    Braz, D.; Lopes, R.T.; Motta, L.M.G. da

    1999-01-01

    Computerized tomography has been an excellent tool of analysis of asphaltics mixtures, because it allows comparison of the quality and integrity of test and field specimens. It was required to detect and follow the evolution of cracks, when these mixtures were submitted to fatigue tests, and also helping to interpret the distribution of tensions and deformations which occur in the several types of solicitations imposed to the mixtures. Comparing the medium values of percentage voids obtained from tomographic images with the project's values, it can be observed that the values of test and field specimens for the wearing course are closer to the ones of the project than the ones of the binder. It can be verified that the wearing course specimens always present a distribution of the aggregate, and voids quite homogeneously in the whole profile of the sample, while the binder specimens show an accentuated differentiation of the same factors in the several heights of the sample. Therefore, when choosing a slice for tomography, these considerations should be taken into account

  11. Determination of the initial energy in computerized tomography with proton beams

    International Nuclear Information System (INIS)

    Rocha, Rodrigo Luis da

    2007-01-01

    In earliest works devoted to proton computed tomography it was shown that the advantage of pCT image reconstruction appears when the energy is close to the Bragg peak region, since the proton passes the object. This effect provided by the Bragg peak makes the computerized tomography with protons possible. However, when decreasing the initial proton energy, with the increase of the irradiation dose, there are two effects that work simultaneously in opposite ways. First, the energy loss of a proton in an object becomes bigger at small initial energy. At the same time decreasing of the proton energy results in the increase of the energy straggling, requiring a larger number of protons. In this work the radiation dose dependence on the proton initial energy was studied using analytical formulas and computer simulations. The investigation determined that the radiation dose practically does not depend on the initial energy, except in the energy region very close to the minimum energy necessary to pass the object. (author)

  12. Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis.

    Science.gov (United States)

    O'Neill, Marisol; Huang, Gene O; Lamb, Dolores J

    2017-12-01

    The murine penis model has enriched our understanding of anomalous penile development. The morphologic characterization of the murine penis using conventional serial sectioning methods is labor intensive and prone to errors. To develop a novel application of micro-computerized tomography (micro-CT) with iodine staining for rapid, non-destructive morphologic study of murine penis structure. Penises were dissected from 10 adult wild-type mice and imaged using micro-CT with iodine staining. Images were acquired at 5-μm spatial resolution on a Bruker SkyScan 1272 micro-CT system. After images were acquired, the specimens were washed of any remaining iodine and embedded in paraffin for conventional histologic examination. Histologic and micro-CT measurements for all specimens were made by 2 independent observers. Measurements of penile structures were made on virtual micro-CT sections and histologic slides. The Lin concordance correlation coefficient demonstrated almost perfect strength of agreement for interobserver variability for histologic section (0.9995, 95% CI = 0.9990-0.9997) and micro-CT section (0.9982, 95% CI = 0.9963-0.9991) measurements. Bland-Altman analysis for agreement between the 2 modalities of measurement demonstrated mean differences of -0.029, 0.022, and -0.068 mm for male urogenital mating protuberance, baculum, and penile glans length, respectively. There did not appear to be a bias for overestimation or underestimation of measured lengths and limits of agreement were narrow. The enhanced ability offered by micro-CT to phenotype the murine penis has the potential to improve translational studies examining the molecular pathways contributing to anomalous penile development. The present study describes the first reported use of micro-CT with iodine staining for imaging the murine penis. Producing repeated histologic sections of identical orientation was limited by inherent imperfections in mounting and tissue sectioning, but this was

  13. 'High resolution' computerized tomography in spinal narrow and spinal column diagnosis

    International Nuclear Information System (INIS)

    Koester, O.

    1985-01-01

    Bearing in mind that direct comparison is lacking, high resolution computerized tomography in spinal column diagnosis can be said to supply considerably increased information when dealing with the issues of a cervical prolapse and bony changes of any origin. Its advantages appear to be reduced when assessing lumbar prolapse, intraspinal masses and paravertebral soft-tissue processes. (orig.) [de

  14. Diagnostic Yield of Transbronchial Biopsy in Comparison to High Resolution Computerized Tomography in Sarcoidosis Cases

    Science.gov (United States)

    Akten, H Serpil; Kilic, Hatice; Celik, Bulent; Erbas, Gonca; Isikdogan, Zeynep; Turktas, Haluk; Kokturk, Nurdan

    2018-04-25

    This study aimed to evaluate the diagnostic yield of fiberoptic bronchoscopic (FOB) transbronchial biopsy and its relation with quantitative findings of high resolution computerized tomography (HRCT). A total of 83 patients, 19 males and 64 females with a mean age of 45.1 years diagnosed with sarcoidosis with complete records of high resolution computerized tomography were retrospectively recruited during the time period from Feb 2005 to Jan 2015. High resolution computerized tomography scans were retrospectively assessed in random order by an experienced observer without knowledge of the bronchoscopic results or lung function tests. According to the radiological staging with HRCT, 2.4% of the patients (n=2) were stage 0, 19.3% (n=16) were stage 1, 72.3% (n=60) were stage 2 and 6.0% (n=5) were stage 3. This study showed that transbronchial lung biopsy showed positive results in 39.7% of the stage I or II sarcoidosis patients who were diagnosed by bronchoscopy. Different high resolution computerized tomography patterns and different scores of involvement did make a difference in the diagnostic accuracy of transbronchial biopsy (p=0.007). Creative Commons Attribution License

  15. Regional aspects of cerebral cysticercosis. Incidence and evaluation by computerized tomography in 1000 consecutive studies

    Energy Technology Data Exchange (ETDEWEB)

    Jozzolino, D.A. (Instituto de Tomografia Axial Computadorizada de Londrina (Brazil))

    One thousand consecutive studies of the entire brain were performed and 122 patients with tomographic diagnosis of cysticercosis were found. The high incidence of this disease is discussed and its endemic characteristics as well. Various forms and types are described, the most frequent being the presence of calcifications; other tests performed at the time of computerized tomography are mentioned.

  16. Dose profile measurement in computerized axial tomography equipment using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Azorin V, J.C.; Falcony, C.; Azorin N, J.

    2000-01-01

    In this work are presented the results about measuring the radiation dose profile in two equipment of computerized axial tomography (Tac). Thermoluminescent dosemeters (Dtl) of LiF, Mg, Cu, P + Ptfe in form of disks were used which were developed and made in Mexico. The results showed that Dtl are appropriated for these type of studies. (Author)

  17. Status of routine post-mortem computerized tomography in Odense, Denmark

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2008-01-01

    rarely is a substitute for autopsy, but may contribute with important new information in many cases such as identifications (including mass-disasters), battered child, gunshot wounds, traffic accidents and air embolism. Computerized tomography provides documentation in digital form - easily stored...

  18. Computerized transverse tomography of vascular lesions of the brain. II. Aneurysms

    International Nuclear Information System (INIS)

    Pressman, B.D.; Gilbert, G.E.; Davis, D.O.

    1975-01-01

    Computerized transverse tomography (CTT) is an excellent screening examination for intracerebral disease. Unfortunately, the detection rate of small aneurysms by this procedure is not high. Nevertheless, CTT may be useful in aneurysm cases since it may indicate the need for further evaluation in patients with associated hematomas, encephalomalacia, or ventricular dilatation, even if the aneurysm itself is not delineated. (U.S.)

  19. Can duplex Doppler ultrasound replace computerized tomography in staging patients with renal cell carcinoma?

    NARCIS (Netherlands)

    Bos, SD; Mensink, HJA

    The purpose of this study was to evaluate the accuracy and reliability of duplex Doppler ultrasound (US) and computerized tomography (CT) in staging patients with renal cell carcinoma (RCC). Sixty-six patients were evaluated pre-operatively with duplex Doppler ultrasound and CT. The results were

  20. A modified conjugate gradient method based on the Tikhonov system for computerized tomography (CT).

    Science.gov (United States)

    Wang, Qi; Wang, Huaxiang

    2011-04-01

    During the past few decades, computerized tomography (CT) was widely used for non-destructive testing (NDT) and non-destructive examination (NDE) in the industrial area because of its characteristics of non-invasiveness and visibility. Recently, CT technology has been applied to multi-phase flow measurement. Using the principle of radiation attenuation measurements along different directions through the investigated object with a special reconstruction algorithm, cross-sectional information of the scanned object can be worked out. It is a typical inverse problem and has always been a challenge for its nonlinearity and ill-conditions. The Tikhonov regulation method is widely used for similar ill-posed problems. However, the conventional Tikhonov method does not provide reconstructions with qualities good enough, the relative errors between the reconstructed images and the real distribution should be further reduced. In this paper, a modified conjugate gradient (CG) method is applied to a Tikhonov system (MCGT method) for reconstructing CT images. The computational load is dominated by the number of independent measurements m, and a preconditioner is imported to lower the condition number of the Tikhonov system. Both simulation and experiment results indicate that the proposed method can reduce the computational time and improve the quality of image reconstruction. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Computerized tomography in Community of Madrid. Reference dosimetric measurements

    International Nuclear Information System (INIS)

    Ruiz Sanz, S.; Calzado, A.; Melchor, M.; Marco, M.

    1994-01-01

    A total of about 43 computed tomography scanners were operating in the Autonomous Community of Madrid during 1991. A sample of 14 facilities was selected to perform dosimetric measurements in order to obtain characteristic dose profiles. From these, some quantities as the computed tomography dose index and the enhancement factor were calculated and analysed for the most common technique settings. Relations were established between the dosimetric results and technical characteristics of the scanners. (Author)

  2. Computerized tomography in the diagnosis of mechanical jaundice

    International Nuclear Information System (INIS)

    Grushin, Yu.V.; Manasov, T.Zh.; Raskolenko, A.A.; Nazyrova, N.K.; Dzhumashev, E.Z.

    1987-01-01

    A total of 51 patients with suspected mechanical jaundice were examined using the 3rd generation computerized tomograph. A correct conclusion as to the level and mechanism of obstruction was made in 77% of cases. The most serious problems arose in analysis of extrahepatic biliary ducts. The dilatation of the biliary passages was not always combined with their obturation. In cases which were difficult for interpretation, additional information could be obtained by using thin tomographic layers, i.v. contrast enhancement, and retrograde endoscopic cholangiography

  3. 2D histomorphometric quantification from 3D computerized tomography

    International Nuclear Information System (INIS)

    Lima, Inaya; Oliveira, Luis Fernando de; Lopes, Ricardo T.; Jesus, Edgar Francisco O. de; Alves, Jose Marcos

    2002-01-01

    In the present article, preliminary results are presented showing the application of the tridimensional computerized microtomographic technique (3D-μCT) to bone tissue characterization, through histomorphometric quantification which are based on stereologic concepts. Two samples of human bone were correctly prepared to be submitted to the tomographic system. The system used to realize that process were a radiographic system with a microfocus X-ray tube. Through these three processes, acquisition, reconstruction and quantification, it was possible to get the good results and coherent to the literature data. From this point, it is intended to compare these results with the information due the conventional method, that is, conventional histomorphometry. (author)

  4. Dental status of three Egyptian mummies: radiological investigation by multislice computerized tomography.

    Science.gov (United States)

    Gerloni, Alessandro; Cavalli, Fabio; Costantinides, Fulvio; Costantinides, Fulvia; Bonetti, Stefano; Paganelli, Corrado

    2009-06-01

    The aim of the study was to provide a paleopathologic and radiologic overview of the jaws and teeth of 3 Egyptian mummies preserved in the Civic Museum of History and Art in Trieste. Computerized tomography (CT) imaging and postprocessing techniques were used to examine the oral structures. A 16-slice CT scanner was used (Aquilion 16; Toshiba Medical Systems Europe, Zoetermeer, The Netherlands). Scans were obtained at high resolution. Orthogonal-plane and 3-dimensional (3D) reconstructions were created along with curved reconstructions of the lower and upper jaws. Determination of decayed/missing teeth (DMT) and decayed/missing/tooth surfaces (DMTs) were made with 3D images. Analyses revealed differences in the embalming techniques and state of preservation of the bodies. Marked wear of the occlusal surfaces was a characteristic finding in all of the mummies. The DMT and DMTs were low compared with values for contemporary populations. Two mummies had fully erupted third molars. All mummies exhibited bone changes consistent with periodontitis. The CT evaluations of the oral structures of the mummies provided insight into the dental status and oral diseases of these ancient Egyptians. The low DMT and DMTs values and indications of periodontitis may be associated with the lifestyle of these Egyptians. The fully erupted and well aligned third molars may represent a morphologic adaptation of the arches to the muscular activity associated with grinding tough foods.

  5. Primary muscular hydatid: preoperative diagnosis Throught computerized tomography and ultrasonography

    International Nuclear Information System (INIS)

    Macho Fernandez, J.M.; Marin Cardenas, M.A.; Mazas Artasona, L.; Lample Lacasa, C.; Otero Sierra, C.; Hernandez Navarrete, M.J.; Gomez-Pereda, R.

    1995-01-01

    Primary muscular hydatid disease, is extremely rare,- but not exceptional-, comparatively with other atypical localization. In this article the authors revised 474 patients with hydatid disease over a ten years period. Three cases of primary muscular localization were found. The ultrasonography and computed tomography facilitates the preoperative diagnosis. (Author) 40 refs

  6. Health physics aspects of the EMI computerized tomography brain scanner

    International Nuclear Information System (INIS)

    Villafana, T.; Scouras, J.; Kirkland, L.; McElroy, N.; Paras, P.

    1978-01-01

    The EMI computerized tomographic cranial scanner is one of the first radiological systems incorporating an on-line computer. The result is an increase in the ability to visualize such tissues as grey matter and white matter as well as blood pools and tumor volumes. This advance has already begun to revolutionize radiological practice. Because of the totally different configuration of this unit, concern has been expressed over the dosages received by the patient, consequently the health physics aspects of this unit have been studied. Specifically, doses received by the surface of head and interior brain points as well as by the lens of the eye and gonads are reported here. X-ray output, beam half-value layers and barrier shielding requirements are also reported and discussed. (author)

  7. Diagnostic value of sectional images obtained by emission tomography

    International Nuclear Information System (INIS)

    Roucayrol, J.C.

    1981-01-01

    It is now possible to obtain clear images of the various planes in and around a structure with ultra-sounds (echotomography), X-rays (computerized tomography) and recently, gamma-rays from radioactive substances (emission tomography). Axial transverse tomography, which is described here, is to conventional scintigraphy what CT scan is to radiography. It provides images of any structure capable of concentrating sufficiently a radioactive substance administered intravenously. These images are perpendicular to the longitudinal axis of the body. As shown by examples in the liver, lungs and myocardium, lesions which had passed unnoticed with other exploratory techniques can now be demonstrated, and the location, shape and extension of known lesions can be more accurately assessed. Emission tomography already has its place in modern diagnostic procedures side by side with echotomography and CT scan [fr

  8. Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

    Science.gov (United States)

    Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

    2008-01-01

    Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

  9. A case of multiple intracranial tuberculoma followed by serial computerized tomography

    International Nuclear Information System (INIS)

    Kummer, R. von; Storch, B.; Krause, K.H.; Rauch, H.

    1981-01-01

    This is the case report of an Indian living in Europe who suffered from multiple cerebral tuberculomes in connexion with extrapulmonal tuberculosis. The retrogression of the inflammatory granulomes and the surrounding cerebral edema by treatment with tuberculostatics and Dexamethasone was observed by means of computerized tomography (CT) over a period of 8 months. The value of CT in the diagnosis and treatment of cerebral tuberculomes is discussed. The diagnosis of cerebral tuberculomes is difficult as neither the clinical picture nor additional neuroradiological tests ensure safe delimitation against other intracranial growths. In how far this situation has changed by the introduction of CT into diagnostics is discussed by the example of serial computerized tomography on a patient with multiple cerebral tuberculomes. (orig.) [de

  10. Rupture of Ovarian Mature Cystic Teratoma: Computerized Tomography Findings

    International Nuclear Information System (INIS)

    Sebastia, C.; Sarrias, M.; Sanchez-Aliaga, E.; Quiroga, S.; Boye, R.; Alvarez-Castells, A.

    2004-01-01

    We present computed tomography findings of three cases of intraperitoneal rupture of ovarian mature cystic teratoma. Acute-phase radiological findings include presence of intraabdominal liquid, infiltration of mesenteric fat and calcified pelvic mass which also showed interior fatty content. Chronic-phase findings include infiltration of peritoneal fat, as well as increase in the size of adjacent ganglion due to chronic inflammatory response to histologically verified foreign bodies. Differential diagnoses between chronic and acute intraperitoneal ruptures of mature teratoma have been reviewed. (Author)

  11. Computerized tomography in diagnosis of mammary gland cancer

    International Nuclear Information System (INIS)

    Ternovoj, S.K.; Shishmareva, N.F.

    1987-01-01

    A total of 103 women with suspected malignant breast tumors were examined using combined methods including computed tomography (CT). Cancer was diagnosed in 81 patients benign breast tumors in 22. The authors obtained data concerning CT superiority in the diagnosis of tumors localized in the retromammary space, as well as infinitrative-edematous forms of cancer and breast cancer recurrences. A high reliability of the method in the detection of metastatic involvement of the axillary lymph nodes made it possible to give up transmission axillography

  12. The use of computerized tomography in patients showing tardive dyskinesia

    International Nuclear Information System (INIS)

    Themelis, I.

    1983-01-01

    29 patients showing moderate to markedly pronounced tardive dyskinesia (TD) and a further 29 control patients (C) under a similar long-term medication with neuroleptics that had been so chosen as to match the age and sex distributions of the former group were subjected to computered tomography, neurological examination and psychological testing. The results did not point to any correlations between the structural changes and duration of treatment and the clinical signs or symptoms of extrapyramidal disorder. This was taken as further evidence in support of the theory that the initial damage in tardive dyskinesia mainly is at the level of the basal ganglia. (orig./MG) [de

  13. Cranial computerized tomography aspects of neuro-cysticercosis in infancy

    International Nuclear Information System (INIS)

    Guerreiro, M.M.; Facure, N.O.; Guerreiro, C.A.M.

    1989-01-01

    The analysis of 27 computed tomography scans (CT) is presented. Eighteen children were divided in three groups according to clinical and tomographic criteria. Group 1 was characterized mainly by epilepsy and calcifications. Group 2 was characterized by intracranial hypertension and several tomographic aspects: edema, cysts and nodules were seen in three patients; hydrocephaly and calcifications were seen in two patients and CT was normal is one patient. Group 3 had patients with epilepsy or headache and variable tomographic patterns. The results are discussed based on the available literature. (author)

  14. Computerized tomography in the diagnosis of early and late complications after lung surgery

    International Nuclear Information System (INIS)

    Jeschke, W.; Linder, M.; Weiss, A.; Kihm, W.D.; Kempmann, G.

    1980-01-01

    The advantages of computerized tomography over conventional radiography for correctly interpreting doubtful findings after lung surgery are illustrated by 4 cases histories. In the immediate post-operative period the technique generally succeeds in identifying the nature of the abnormal findings and in differentiating between effusion, infiltration, abscess and empyema. Leakage from the bronchial stump can be clearly demonstrated without inconveniencing the patient. (orig.) [de

  15. A numerical solution of the equation of the computerized tomography and its application in astrophysics

    International Nuclear Information System (INIS)

    Krastev, A.; Nedialkov, J.

    1983-01-01

    A method for numerical solving the equation of the computerized tomography is proposed. The method, is based on the Cormack's formulae and is applied for studying media with central symmetry. The generalization for the nonsymmetric case does not lead to complications. The method is applied for the investigation of the density distribution of the Earth, the other planets and the Sun by means of neutrino experiments

  16. Testing objects in Computerized Axial Tomography. Contributions to the Spanish Protocol on quality control in radiodiagnostics

    International Nuclear Information System (INIS)

    Villaescusa, J.I.; Campayo, J.M.

    1995-01-01

    In the provisional version of the Spanish Protocol about the technical aspects of Quality Control in Radiodiagnostic,SEFM-SEPR 1993, it is dedicated a section to Computerized Axial tomography, establishing a total of eleven technical parameters of the equipment for examination. The present work describes the practical use of the Protocol using various types of Test Object. The authors also propose new tests that should be considered in the final version of the Spanish Protocol. (Author)

  17. Computerized transverse tomography of vascular lesions of the brain. I. Arteriovenous malformations

    International Nuclear Information System (INIS)

    Pressman, B.D.; Kirkwood, J.R.; Davis, D.O.

    1975-01-01

    Computerized transverse tomography (CTT) of the brain is a recently developed method which allows non-invasive roentgenologic evaluation of intracranial disease. Since its inception, major attention has been given to the diagnosis and evaluation of tumors, clots, infarcts, venticular size, and orbital lesions. The purpose of this report is to discuss the application of CTT to the diagnosis and evaluation of intracerebral arteriovenous malformations. (U.S.)

  18. Dose profile study on computerized tomography scanning of skull with simulator object

    International Nuclear Information System (INIS)

    Mourao, A.P.

    2011-01-01

    This work presents a comparison among the dose profiles in scanning of computerized tomography of a simulator object of PMMA in its periphery region. To obtain the deposited dose at the PMMA thermoluminescent dosemeters were used positioned at the interior of PMMA simulated object longitudinal to periphery and at the center of cylinder (positions denominated North, South, East, West and Center). Eight scanning were performed of simulator object using the routine protocol for skull in eight different services of radiodiagnostic by TC

  19. Extension of the Gladstone-Dale equation for flame flow field diagnosis by optical computerized tomography

    International Nuclear Information System (INIS)

    Chen Yunyun; Li Zhenhua; Song Yang; He Anzhi

    2009-01-01

    An extended model of the original Gladstone-Dale (G-D) equation is proposed for optical computerized tomography (OCT) diagnosis of flame flow fields. For the purpose of verifying the newly established model, propane combustion is used as a practical example for experiment, and moire deflection tomography is introduced with the probe wavelength 808 nm. The results indicate that the temperature based on the extended model is more accurate than that based on the original G-D equation. In a word, the extended model can be suitable for all kinds of flame flow fields whatever the components, temperature, and ionization are.

  20. Dosimetric characterization of computerized tomography of 64 channels

    International Nuclear Information System (INIS)

    Gimeno-Fernandez, V.; Sotil-Baylos, J.; Garcia-Pazos, M.; Garcia-Pena, P.

    2006-01-01

    As a first step in the evaluation of effective dose to patients in Computed Tomography (CT) examinations, the purpose of this work was the assessment of the dose delivered by a new multislice scanner of 64 channels (Philips Brilliance 64c). This was done through the measurement of the CT Dose Index free in air, normalized to the unit of applied charge, using different beam collimations and tube voltages. Fitting nonlinear models to the observed data, kilo voltage and over beaming (penumbra) parameters have been elicited. The kilo voltage exponent of the relationship between CT dose index and kilo voltage varies from 2,84 to 2,88. The obtained penumbra with was 2,04 nm. Finally, corrections factors that must be applied to the measured dose indexes as a function of the applied collimation have been established from the estimated analytical relationships. (Author)

  1. Computerized axial tomography and diagnosis of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Paulo R.M. Bittencourt

    1983-06-01

    Full Text Available Computed axial tomography (C.T. findings are illustrated in 3 patients who presented with C.T. changes suggesting respectively chronic M.S., acute M.S., and an appearance simulating a malignant tumour. Review of the literature shows that the chronic form with cerebral atrophy and low density lesions in the hemispheres is common in patients with a long history and is unlikely to cause diagnostic difficulty. The acute presentation is less common and could be confused with a variety of causes of multiple low density enhancing lesions. The C.T. diagnosis of M.S. is more difficult in rare cases in which plaques cause mass effect and show ring enhancement; all 3 such cases in the literature were subjected to cerebral biopsy.

  2. Clinical manifestations in patients with computerized tomography diagnosis of neurocysticercosis

    International Nuclear Information System (INIS)

    Pfuetzenreiter, Marcia Regina; Avila-Pires, Fernando Dias de

    1999-01-01

    A survey was conducted in the urban area of Lages using patients who had been submitted to a computed tomography of the skull in the period of March-December, 1996, for different reasons. Forty-two patients with a provisional diagnosis of neurocysticercosis, and 57 negatives were personally interviewed by one of the authors (Pfuetzenreiter), using a semi-structured procedure. More individuals with a provisional diagnostic of neurocysticercosis reported clinical manifestations related to this infection than those found negative. this difference is more marked among women, except in relation to convulsions, more frequently reported by men (19.05%) than by women (7.14%). The greater percentage of inactive forms (83.33%0 and a longer history of perceived symptoms among those positives suggest that the condition is not new. (author)

  3. New applications to computerized tomography: analysis of solid dosage forms produced by pharmaceutical industry

    International Nuclear Information System (INIS)

    Oliveira Junior, Jose Martins de; Martins, Antonio Cesar Germano

    2009-01-01

    Full text: In recent years, computerized tomography (CT) has been used as a new probe to study solid dosage forms (tablets) produced by pharmaceutical industry. This new approach to study tablet and powder, or granulation, properties used in pharmaceutical industry is very suitable. First because CT can generate information that traditional technologies used in this kind of analysis can not, such as, density distribution of internal structures and tablet dimensions, pore size distribution, particle shape information, and also investigation of official and unofficial (counterfeit) copies of solid dosage forms. Second because CT is a nondestructive technique, allowing the use of tablets or granules in others analysis. In this work we discus how CT can be used to acquire and reconstruct internal microstructure of tablets and granules. CT is a technique that is based on attenuation of X-rays passing through matter. Attenuation depends on the density and atomic number of the material that is scanned. In this work, a micro-CT X-ray scanner (manufactured by the group of Applied Nuclear Physics at University of Sorocaba) was used to obtain three-dimensional images of the tablets and granules for nondestructive analysis. These images showed a non uniform density distribution of material inside some tablets, the morphology of some granules analyzed, the integrity of the liquid-filled soft-gelatin capsule and so on. It could also be observed that the distribution of different constituents presents an osmotic controlled-release dosage form. The present work shows that it is possible to use X-ray microtomography to obtain useful qualitative and quantitative information on the structure of pharmaceutical dosage forms. (author)

  4. Quality criteria in computerized tomography of the pelvis

    International Nuclear Information System (INIS)

    Lindner, P.

    1985-01-01

    The author thinks that observation of the following recommendations will result in qualitatively satisfying visualization of the pelvis region concerned: 1) Technically perfect state of the imaging chain ranging from the recording of absorption data of the human body to the reproduction of the calculated image on the hard-copy unit; 2) Suitable choice of dose, voltage, cut thickness and number of projections; 3) Application and selection of examination technique in accordance with the medical issue. 4) Selection of window position and window width matched to the medical issue. 5) Suitable window width or matrix demonstration for detecting soft-tissue processes and/or bone processes. (orig./MG) [de

  5. Use of SMT phototransistors for dosimetry in computerized tomography

    International Nuclear Information System (INIS)

    Magalhaes, C.M.S. de; Silva, J.O. da; Antonio Filho, J.; Santos, L.A.P. dos

    2007-01-01

    A dosimetry system using commercially available SMT (Surface-Mount Technology) phototransistors is evaluated for dose measurements in X-ray computed tomography. First, the phototransistors were characterized at the laboratory using a Pantak X-ray in the standard radiation quality RQR9 from IEC61267. The following tests were realized: energy dependence, response with dose rate and repetitiveness. The phototransistors yielded a real-time readout and a 6430 Sub-femto-ammeter Keithley was used to obtain their electrical current. This methodology allowed the correlating of their results with a standard ionisation chamber, a NE2571 ionization chamber coupled to a NE2670 electrometer that measured the applied dose at the detector position. After the characterization of the phototransistors, free-in-air and in head phantom dose measurements were carried out with the dosimetry system at the Hospital. Phototransistors were used to determine the dose profile measurements along the axis of rotation undergoing CT head examination. A Flip-Flop electrometer was used to obtain these measurements. The results indicated that the current values were reliable when compared with the results of doses of CT ionization chamber under the same conditions. The loss of radiation sensitivity, postirradiation, with time is not significant and the SMT phototransistor brings some features to CT dosimetry including high sensitivity, small size, real-time measurements and linearity. (author)

  6. Clinical features and computerized tomography in chronic schizophrenia

    International Nuclear Information System (INIS)

    Shimada, Hitoshi; Nagayama, Motowo; Hori, Akira

    1990-01-01

    Computed tomography (CT) scans and clinical manifestations were compared in severe (53) and mild (42) schizophrenic patients. Severe patients were defined as having been hospitalized during the previous 3 years or more, and mild patients as having lived at home. Regarding psychiatric symptoms, behavior, dosage of antipsychotic agents, and admission duration or disease duration, there were significant differences between the severe and mild groups. Both Hasegawa's and Moriya's dementia rating scales were significantly lower in the severe group than the mild group. Cranial CT scans were analyzed for the Sylvian fissure, third ventricle, body of the lateral ventricle, frontal lobe, and parietofrontal cortex. There were significant differences in CT scans for the Sylvian fissure, third ventricle, and body of the lateral ventricle between the severe and mild groups. For the other two sites, no significant differences were observed. The Sylvian fissure was significantly dilatated in the severe group. Dilatation of the Sylvian fissure was well correlated with clinical manifestations, such as language, feeling expression, decreased will, strange behavior, and disease recognition, reflecting clinical severity. (N.K.)

  7. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

    OpenAIRE

    Acar, Buket; Kamburo?lu, K?van?; Tatar, ?lkan; Ar?kan, Volkan; ?elik, Hakan Hamdi; Y?ksel, Selcen; ?zen, Tuncer

    2015-01-01

    Purpose This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Materials and Methods Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this s...

  8. Computerized tomography in bone and soft tissue tumors

    International Nuclear Information System (INIS)

    Isobe, Yasushi; Kaneta, Koichi; Kawaguchi, Tomoyoshi; Wada, Shigehito; Matsumoto, Seiichi

    1982-01-01

    The contribution to pretreatment evaluation and surgical planning of 238 CT image of bone and soft tissue lesions was evaluated. Their accuracy was studied by careful postoperative examination of gross surgical specimens and histologic sections. CT was helpful in delineating the anatomic extent of lesions and, therefore, in planning the appropriate resection. CT was of little help in confirming or detecting residual or recurrent tumor after prior resection. CT was not accurate or helpful in distinguishing benign from malignant lesions when the clinical presentation and roentgenographic findings were confusing. (author)

  9. Computerized tomography in bone and soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Isobe, Yasushi; Kaneta, Koichi; Kawaguchi, Tomoyoshi; Wada, Shigehito; Matsumoto, Seiichi (Japanese Foundation for Cancer Research, Tokyo. Hospital)

    1982-11-01

    The contribution to pretreatment evaluation and surgical planning of 238 CT image of bone and soft tissue lesions was evaluated. Their accuracy was studied by careful postoperative examination of gross surgical specimens and histologic sections. CT was helpful in delineating the anatomic extent of lesions and, therefore, in planning the appropriate resection. CT was of little help in confirming or detecting residual or recurrent tumor after prior resection. CT was not accurate or helpful in distinguishing benign from malignant lesions when the clinical presentation and roentgenographic findings were confusing.

  10. Computerized emission transaxial tomography and determination of local brain function

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Alavi, A.; Reivich, M.; Edwards, R.Q.; Fenton, C.A.; Zimmerman, R.A.

    1975-01-01

    Accurate knowledge of regional function in the brain would be of great value for the detection and localization of a wide variety of diseases and for assessment of patients under treatment. The management of patients would be greatly improved with a day-to-day knowledge of the status of blood flow, blood volume, metabolism, permeability, brain swelling, and other functions on a local basis throughout the brain. In the past this kind of information has not been available. Instead, function has usually been examined only for the organ as a whole and regional information has been restricted to morphology as determined by radiographic or radionuclide imaging studies. Three-dimensional radionuclide reconstruction imaging will become more important in the study of the brain, providing accurate measurement of radionuclide concentration within functional structural units of the brain. Measurement of local function with three-dimensional resolution throughout the brain and without the necessity for intracarotid injection of indicator could therefore provide a significant advance over presently available methods

  11. Using three-dimensional-computerized tomography as a diagnostic tool for temporo-mandibular joint ankylosis: a case report.

    Science.gov (United States)

    Kao, S Y; Chou, J; Lo, J; Yang, J; Chou, A P; Joe, C J; Chang, R C

    1999-04-01

    Roentgenographic examination has long been a useful diagnostic tool for temporo-mandibular joint (TMJ) disease. The methods include TMJ tomography, panoramic radiography and computerized tomography (CT) scan with or without injection of contrast media. Recently, three-dimensional CT (3D-CT), reconstructed from the two-dimensional image of a CT scan to simulate the soft tissue or bony structure of the real target, was proposed. In this report, a case of TMJ ankylosis due to traumatic injury is presented. 3D-CT was employed as one of the presurgical roentgenographic diagnostic tools. The conventional radiographic examination including panoramic radiography and tomography showed lesions in both sides of the mandible. CT scanning further suggested that the right-sided lesion was more severe than that on the left. With 3D-CT image reconstruction the size and extent of the lesions were clearly observable. The decision was made to proceed with an initial surgical approach on the right side. With condylectomy and condylar replacement using an autogenous costochondral graft on the right side, the range of mouth opening improved significantly. In this case report, 3D-CT demonstrates its advantages as a tool for the correct and precise diagnosis of TMJ ankylosis.

  12. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  13. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  14. Paperback atlas of anatomical sectional images: Computerized tomography and NMR imaging. Vol. 1. Head, neck, vertebral column, joints; Taschenatlas der Schnittbildanatomie: Computertomographie und Kernspintomographie. Bd. 1. Kopf, Hals, Wirbelsaeule, Gelenke

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, T.B. [Caritas-Krankenhaus, Dillingen (Germany); Reif, E. [Caritas-Krankenhaus, Dillingen (Germany)

    1993-12-31

    Using the nomenclature relating to X-ray findings, the paperback atlas provides a concise, yet accurate description of fine anatomical structures visualized by sectional imaging procedures. Each of the approx. 250 sample images shown for the regions of the head (including neurocranium), vertebral column, neck, thorax, abdomen and muscosceletal system (including joints) is supplemented with a drawing that permits an immediate identification of any structure of interest. (orig.) [Deutsch] Der Taschenatlas beschreibt komprimiert und unter Verwendung der roentgenspezifischen Nomenklatur die anatomischen Details der Schnittbilddiagnostik. Jedem der rund 250 exemplarischen Schnittbilder aus den Bereichen Kopf (inkl. Neurokranium), Wirbelsaeule, Hals, Thorax, Abdomen und muskuloskeletalem System (inkl. Gelenke) ist eine Zeichnung zugeordnet, die das rasche Auffinden der jeweils gesuchten Struktur ermoeglicht. (orig.)

  15. Non-destructive analysis and detection of internal characteristics of spruce logs through X computerized tomography

    International Nuclear Information System (INIS)

    Longuetaud, F.

    2005-10-01

    Computerized tomography allows a direct access to internal features of scanned logs on the basis of density and moisture content variations. The objective of this work is to assess the feasibility of an automatic detection of internal characteristics with the final aim of conducting scientific analyses. The database is constituted by CT images of 24 spruces obtained with a medical CT scanner. Studied trees are representative of several social status and are coming from four stands located in North-Eastern France, themselves are representative of several age, density and fertility classes. The automatic processing developed are the following. First, pith detection in logs dealing with the problem of knot presence and ring eccentricity. The accuracy of the localisation was less than one mm. Secondly, the detection of the sapwood/heart-wood limit in logs dealing with the problem of knot presence (main source of difficulty). The error on the diameter was 1.8 mm which corresponds to a relative error of 1.3 per cent. Thirdly, the detection of the whorls location and comparison with an optical method. Fourthly the detection of individualized knots. This process allows to count knots and to locate them in a log (longitudinal position and azimuth); however, the validation of the method and extraction of branch diameter and inclination are still to be developed. An application of this work was a variability analysis of the sapwood content in the trunk: at the within-tree level, the sapwood width was found to be constant under the living crown; at the between-tree level, a strong correlation was found with the amount of living branches. A great number of analyses are possible from our work results, among others: architectural analysis with the pith tracking and the apex death occurrence; analysis of radial variations of the heart-wood shape; analysis of the knot distribution in logs. (author)

  16. Computerized tomography of the lumbar vertebral column after intervertebral disk operation. Pt. 1

    International Nuclear Information System (INIS)

    Schindler, G.; Klott, K.

    1984-01-01

    Problems after intervertebral disk operations are to be expected in about 25-40% of the patients operated. Progressive degnerative alterations at the disks, the vertebrae and the intervertebral joints entail chronic mechanical pain resulting from the sensitive innervation of the structures mentioned, or lead in severe cases to the alteration of the epidural space respectively the spinal nerves with corresponding peripheral neurological symptoms. As post-surgical complications spondylodiscitis, spondylitis, haematomae, liquor fistulae, and split-off bone fragments can be the cause of complaints, for which computerized tomography is a better diagnostical method than myelography. (BWU) [de

  17. Use of computerized tomography in the Multibrauch Research and Technology Complex ''Eye microsurgery''

    International Nuclear Information System (INIS)

    Fedorov, S.N.; Ivashina, A.I.; Anisimov, S.I.; Prokopenko, L.N.; Moskvichev, A.L.

    1989-01-01

    The paper is devoted to analysis of the results of computerized tomography (CT) in 1000 patients examined in te Multibranch Research and Technology Complex ''Eye Microsurgery''. The specific feature of CT in this institution is that 52% of all investigations of ophthalmological patients fall to the share of eyeball abnormality and 40% - to a study of the other parts of the organ of vision. CT indications are extended for low tension glaucoma, complicated high myopia, and for monitoring the position of microsurgical implants. The use of CT is such a highly specialized medical institution as the MRTC ''Eye Microsurgery'' is considered indispensable

  18. Intoxication for methyl alcohol: computerized tomography and finding in the necrosis

    International Nuclear Information System (INIS)

    Abaitua Ibanez, J.M.; Garcia Monco, J.C.; Gallardo Rebollan, S.; Hernando Aguado, G.; Alcaraz, R.; Lopez-Ruiz, J.A.

    1994-01-01

    We present a case of voluntary intake of methyl alcohol studied by means of computerized tomography (CT) in a previously healthy patient. The classical findings of bilateral putaminal necrosis are corroborated and cerebral white matter lesions are detected in frontal and occipital zones, signs that are unusual in this disorder. CT can be of diagnostic interest in certain comas of metabolic origin such as methanol intoxication, revealing antemortem lesions of both putamens and white matter. Finally, a correlation between the CT and necropsy findings is established. (Author) 11 refs

  19. Study of the human encephalon morphology by computerized axial tomography in neurological diseases

    International Nuclear Information System (INIS)

    Loynaz Fernandez, Clara Silvia; Milan Companioni, Daile; Gomez Padron, Ivo; Alvarez Leon, Oladys; Espinosa Quiros, Desiderio

    2001-01-01

    Since the middle of the last century, the study of the human encephalon morphology has been of great interest for the researchers. With the introduction of the computerized axial tomography in 1974, it was possible to expand the knowledge about this area and at the same time provide information on the structural lesions that are pathologies of great psychosocial repercussion like epilepsy and Parkinsonism. This paper used 90 tomographic studies on people aged 20-80 years. A series of linear measurements were made and statistically processed. The results showed variations in linear measurements among control, epileptic and Parkinsonian subjects

  20. Detection of drugs and explosives using neutron computerized tomography and artificial intelligence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, F.J.O. [Instituto de Engenharia Nuclear, Cidade Universitaria, Rio de Janeiro, CEP 21945-970, Caixa Postal 68550 (Brazil)], E-mail: fferreira@ien.gov.br; Crispim, V.R.; Silva, A.X. [DNC/Poli, PEN COPPE CT, UFRJ Universidade Federal do Rio de Janeiro, CEP 21941-972, Caixa Postal 68509, Rio de Janeiro (Brazil)

    2010-06-15

    In this study the development of a methodology to detect illicit drugs and plastic explosives is described with the objective of being applied in the realm of public security. For this end, non-destructive assay with neutrons was used and the technique applied was the real time neutron radiography together with computerized tomography. The system is endowed with automatic responses based upon the application of an artificial intelligence technique. In previous tests using real samples, the system proved capable of identifying 97% of the inspected materials.

  1. Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

    Science.gov (United States)

    Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

    1980-01-01

    Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

  2. Effect of quantization and interpolation of projections on the sensitivity of computerized tomography

    International Nuclear Information System (INIS)

    Vajnberg, Eh.I.; Fajngojz, M.L.

    1984-01-01

    The sources and forms of manifestation of errors in quantization and interpolation of projections in case of X-ray computerized tomography are considered and quantitative criteria of their evaluation are formulated. The dominating role of the interaction of two successive quantizations of projections - one-dimensional and two-dimensional ones is revealed. The necessity of joint optimization of the two-dimensional quantization range, expansion and form of interpolation function, quantized convolution nucleus is substantiated. The experimental results at aspect ratio of tomograms 256x256 and 480 projections are presented

  3. Detection of drugs and explosives using neutron computerized tomography and artificial intelligence techniques

    International Nuclear Information System (INIS)

    Ferreira, F.J.O.; Crispim, V.R.; Silva, A.X.

    2010-01-01

    In this study the development of a methodology to detect illicit drugs and plastic explosives is described with the objective of being applied in the realm of public security. For this end, non-destructive assay with neutrons was used and the technique applied was the real time neutron radiography together with computerized tomography. The system is endowed with automatic responses based upon the application of an artificial intelligence technique. In previous tests using real samples, the system proved capable of identifying 97% of the inspected materials.

  4. Contrast-enhanced multidetector computerized tomography for odontogenic cysts and cystic-appearing tumors of the jaws: is it useful?

    Science.gov (United States)

    Kakimoto, Naoya; Chindasombatjaroen, Jira; Tomita, Seiki; Shimamoto, Hiroaki; Uchiyama, Yuka; Hasegawa, Yoko; Kishino, Mitsunobu; Murakami, Shumei; Furukawa, Souhei

    2013-01-01

    The purpose of this study was to investigate the usefulness of computerized tomography (CT), particularly contrast-enhanced CT, in differentiation of jaw cysts and cystic-appearing tumors. We retrospectively analyzed contrast-enhanced CT images of 90 patients with odontogenic jaw cysts or cystic-appearing tumors. The lesion size and CT values were measured and the short axis to long axis (S/L) ratio, contrast enhancement (CE) ratio, and standard deviation ratio were calculated. The lesion size and the S/L ratio of keratocystic odontogenic tumors were significantly different from those of radicular cysts and follicular cysts. There were no significant differences in the CE ratio among the lesions. Multidetector CT provided diagnostic information about the size of odontogenic cysts and cystic-appearing tumors of the jaws that was related to the lesion type, but showed no relation between CE ratio and the type of these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Evaluation of standard and use tendency of image diagnosis exams in Brazil with emphasis in pediatric computerized tomography; Avaliacao do padrao e tendencia de uso de exames de diagnostico por imagem no Brasil com enfase em tomografia computadorizada pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Dovales, Ana Cristina Murta

    2016-07-01

    There is little information on developing countries about the use of diagnostic imaging procedures and the doses associated with radiological examinations. This study assessed the pattern and trend of diagnostic imaging usage in outpatients of the Brazilian Unified Health System (SUS) by modality and examined body part. Emphasis was given to computed tomography (CT) scans for which the analysis was extended to the private health care sector and included the evaluation of age at examination distribution, and dose estimation for children and young adults. Information on the use of diagnostic imaging procedures among SUS outpatients was obtained from the Outpatient Information System (SIA) of the Department of Information Technology of SUS (DATASUS). Data on the use of CT in the private health care sector were extracted from the Radiological Information Systems (RIS) of 25 private radiology services in 8 Brazilian cities. Effective doses and absorbed doses on organs of interest were estimated individually for 4,497 patients younger than 20 years of age using CT scan technical parameters and Monte Carlo simulations of radiation transport. Between 2002 and 2012 it was observed that conventional radiology was the most frequent modality of diagnostic imaging in SUS outpatients, but more sophisticated modalities, such as CT and magnetic resonance imaging, had the highest growth rates over the study period. The most frequent CT scan in SUS outpatients between 2001 and 2011 was the head/neck exam, but abdomen/pelvis examinations were the ones that grew the most. Patients up to 20 years of age made approximately 13% and 9% of the CT examinations between 2008 and 2014 in the public and private health care systems, respectively. About one-third of the private-sector patients had more than one CT scan in this period. There was great variation in doses, even for the same type of procedure in patients of the same age group. The highest mean effective dose was 13.5 mSv estimated

  6. Can carotid stenosis be operated without arteriography? Contribution of magnetic resonance and helical computerized tomography angiography

    International Nuclear Information System (INIS)

    Auffrau-Calvier, E.; Kersaint-Gilly, A. de; Desal, H.A.; Viarouge, M.P.; Havet, T.

    1996-01-01

    The aim of this work is to ascertain the role of the magnetic resonance angiography (MRA) and to compare it with the Doppler effect, the X-ray angiography and the new method of helical computerized tomography. Seventy one carotid bifurcations in 37 patients with suspected cerebral vascular events has been evaluated with the MRA and digitalized angiography, the reference method. The obtained data corroborate the good results proposed by other authors reporting in the literature and allow to propose this examination as a new means of investigating carotid bifurcations. Work with the helical computerized tomography appears to be promising too but there are few reported series. Therefore, there appears to be two interesting points: the reliability of distinguishing between very severe stenosis and occlusion, and the fine-tuned analysis of the plaque with detection of ulcerations. When a consistent approach is used to the evaluation of the carotid bifurcation, the Willis circle and the cerebral parenchyma, the MRA can complete the Doppler echo data and the preoperative arteriography can only be used in patients when the MRA and the Doppler echo results disagree. (authors)

  7. The application of computerized tomography in the diagnosis of renal diseases

    International Nuclear Information System (INIS)

    Rzymski, K.

    1980-01-01

    The purpose of the report is presentation of the experiences collected in the diagnosis of renal changes obtained by means of computerized tomography after application of this method in 800 examinations of the abdominal cavity. In 88 cases the examination was performed because of diagnosed or supposed renal disease. The examination was done using an EMI Medical CT 5005/2 whole-body scanner. In the group of 88 cases in 22 unilateral or bilateral hydronephros was diagnosed, in 16 cases single cysts were demonstrated in the kidneys, in 5 polycystic renal disease, in 9 malignant neoplasms and in 11 nephrosclerosis were found. Besides that, atrophic kidneys were recognized and patients were examined after nepherctomy carried out for neoplasm. The final diagnosis was based on surgical, autopsy, angiographic and clinical findings. Computerized tomography of the kidneys is important mainly as a method supplementing traditional methods of examination of the kidneys. The main indication to the use of this method as the first radiological examination of the kidneys is in search for the cause of morphological renal failure, so called ''dumb kidney'' in urography, and in search for retroperitoneal metastases and recurrences after operations of renal neoplasms. In all other circumstances it should be accepted as a rule to begin renal examination with plain-film taking and intravenous urography, which methods together with other classic radiological methods make possible recognition of the causes of renal diseases in most cases. (author)

  8. Spontaneous intracerebral haematomas - the influence of computerized tomography on the results of surgery

    International Nuclear Information System (INIS)

    Kolodziejczyk, D.

    1981-01-01

    The report covers 30 patients of 10 to 74 years of age who has hard spontaneous intracerebral haematomas in the time from 1975 to 1980 and had been operated on after diagnosing by means of computerized tomography. The total mortality rate was 40% and was not significantly different from the total operative result obtained by other authors in the CT-period, but it compares poor to the pre-CT-aera. This deterioration despite improved diagnoses might be an effect of computerized tomography on the operating surgeon. Out of 18 survivors, 8 were completely healed. 4 patients kept some neurological symptoms, but could manage everyday life on their own. 6 patients kept serious neurological defects needing care. The influence of neurological-clinical parameters on the final operation result hasn't lost its importance in the CT-aera. The value of CT for the therapy of intracerebral haematomas lies in course control which often justifies a conservative proceeding with good absorption tendency taking into consideration the clinical-neurological picture, despite the persistence of growing and displacing processes. (orig./MG) [de

  9. Three-dimensional computerized tomography. Clinical value in the case of skeletal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P.; Genant, H.K.

    1988-01-07

    Three-dimensional computed tomography (3-D CT) was performed in 157 patients with disorders of the musculoskeletal system. 3-D CT facilitated the understanding of complex abnormalities of osseous structures. 3-D CT was particularly useful in evaluating trauma, bone tumors and the postoperative spine. Three-dimensional imaging is a useful adjunct imaging method supplementing conventional computed tomography. 3-D CT facilitates preoperative planning and intraoperative localization. The combination of three-dimensional computed tomography, computer assisted design and computer assisted modelling (CAD/CAM) allows the generation of plastic models for preoperative surgical planning and simulation as well as the generation of custom-molded prostheses.

  10. Emission tomography for adrenal imaging

    International Nuclear Information System (INIS)

    Britton, K.E.; Shapiro, B.; Hawkins, L.A.

    1980-01-01

    Single photon emission tomography (SPET) of the adrenals was compared to convential gamma camera images. Depths of 19 adrenals were assessed by both the lateral skin-upper kidney pole method and by SPET. Eleven patients with adrenal disorders were also studied. An advantage of using SPET was that the analogue transverse section image showed improvement over the conventional posterior view because the liver activity was well separated from the adrenal. Furthermore, non-adrenal tissue background was virtually eliminated and adrenal depth determination facilitated. (U.K.)

  11. Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

    Science.gov (United States)

    McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R

    To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations

  12. Density evaluation by computerized tomography in plain soils over different manipulation systems; Avaliacao da densidade pelo metodo da tomografia computadorizada de um planossolo sob diferentes sistemas de manejo

    Energy Technology Data Exchange (ETDEWEB)

    Pedrotti, Alceu [Lavras Univ., MG (Brazil). Dept. de Ciencia do Solo; Pauletto, Eloy Antonio [Pelotas Univ., RS (Brazil). Dept. de Solos; Crestana, Silvio [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Centro Nacional de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria (CNPDIA)

    1996-08-01

    The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic 1 fig.

  13. Value of conventional tomography and computerized tomography in therapy resistant affections of the nasal sinuses

    International Nuclear Information System (INIS)

    Rieden, K.; Frey, M.; Mayer, B.

    1986-01-01

    The informational value of conventional tomography as primary diagnostic method is pointed out in diseases of nasal sinuses resistant to therapy. 5 cases demonstrate the additional information gained by CT-differentiation of soft tissue structures, intraorbital and intracranial expansion. In 78.4% of the examined group of 51 patients conventional tomography allowed the diagnosis of a process limited to the nasal sinuses, further evidence by CT could be omitted. In 11 patients examined by CT additionally, the expansion of the process was defined more precisely and the assumed intraorbital and intracranial growth confirmed. (orig.) [de

  14. Prediction of differential creatinine clearance in chronically obstructed kidneys by non-contrast helical computerized tomography

    International Nuclear Information System (INIS)

    Ng, Cheuk Fan; Chan, L.W.; Cheng, C.W.; Yu, S.C.H.; Wong, W.S.; Wong, K.T.

    2004-01-01

    Purpose: We investigate the use of non-contrast helical computerized tomography (NCHCT) in the measurement of differential renal parenchymal volume as a surrogate for differential creatinine clearance (Cr Cl) for unilateral chronically obstructed kidney. Materials And Methods: Patients with unilateral chronically obstructed kidneys with normal contralateral kidneys were enrolled. Ultrasonography (USG) of the kidneys was first done with the cortical thickness of the site with the most renal substance in the upper pole, mid-kidney, and lower pole of both kidneys were measured, and the mean cortical thickness of each kidney was calculated. NCHCT was subsequently performed for each patient. The CT images were individually reviewed with the area of renal parenchyma measured for each kidney. Then the volume of the slices was summated to give the renal parenchymal volume of both the obstructed and normal kidneys. Finally, a percutaneous nephrostomy (PCN) was inserted to the obstructed kidney, and Cr Cl of both the obstructed kidney (PCN urine) and the normal side (voided urine) were measured two 2 after the relief of obstruction. Results: From March 1999 to February 2001, thirty patients were enrolled into the study. Ninety percent of them had ureteral calculi. The differential Cr Cl of the obstructed kidney (%CrCl) was defined as the percentage of Cr Cl of the obstructed kidney as of the total Cr Cl, measured 2 weeks after relief of obstruction. The differential renal parenchymal volume of the obstructed kidney (%CTvol) was the percentage of renal parenchymal volume as of the total parenchymal volume. The differential USG cortical thickness of the obstructed kidney (%USGcort) was the percentage of mean cortical thickness as of the total mean cortical thickness. The Pearson's correlation coefficient (r) between %CTvol and %CrCl and that between %USGcort and %CrCl were 0.756 and 0.543 respectively. The regression line was %CrCl = (1.00) x %CTvol - 14.27. The %CTvol

  15. Prediction of differential creatinine clearance in chronically obstructed kidneys by non-contrast helical computerized tomography

    Directory of Open Access Journals (Sweden)

    Ng C.F.

    2004-01-01

    Full Text Available PURPOSE: We investigate the use of non-contrast helical computerized tomography (NCHCT in the measurement of differential renal parenchymal volume as a surrogate for differential creatinine clearance (CrCl for unilateral chronically obstructed kidney. MATERIALS AND METHODS: Patients with unilateral chronically obstructed kidneys with normal contralateral kidneys were enrolled. Ultrasonography (USG of the kidneys was first done with the cortical thickness of the site with the most renal substance in the upper pole, mid-kidney, and lower pole of both kidneys were measured, and the mean cortical thickness of each kidney was calculated. NCHCT was subsequently performed for each patient. The CT images were individually reviewed with the area of renal parenchyma measured for each kidney. Then the volume of the slices was summated to give the renal parenchymal volume of both the obstructed and normal kidneys. Finally, a percutaneous nephrostomy (PCN was inserted to the obstructed kidney, and CrCl of both the obstructed kidney (PCN urine and the normal side (voided urine were measured two 2 after the relief of obstruction. RESULTS: From March 1999 to February 2001, thirty patients were enrolled into the study. Ninety percent of them had ureteral calculi. The differential CrCl of the obstructed kidney (%CrCl was defined as the percentage of CrCl of the obstructed kidney as of the total CrCl, measured 2 weeks after relief of obstruction. The differential renal parenchymal volume of the obstructed kidney (%CTvol was the percentage of renal parenchymal volume as of the total parenchymal volume. The differential USG cortical thickness of the obstructed kidney (%USGcort was the percentage of mean cortical thickness as of the total mean cortical thickness. The Pearson's correlation coefficient (r between %CTvol and %CrCl and that between %USGcort and %CrCl were 0.756 and 0.543 respectively. The regression line was %CrCl = (1.00 x %CTvol - 14.27. The %CTvol

  16. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars.

    Science.gov (United States)

    Acar, Buket; Kamburoğlu, Kıvanç; Tatar, İlkan; Arıkan, Volkan; Çelik, Hakan Hamdi; Yüksel, Selcen; Özen, Tuncer

    2015-12-01

    This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

  17. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Buket; Kamburoglu, Kivanc [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan); Tatar, Ilkan [Dept. of Anatomy, Faculty of Medicine, Hacettepe University, Ankara (Turkmenistan); Arikan, Volkan [Dept. of Anatomy, Faculty of Medicine, Hacettepe University, Ankara (Turkmenistan); Celik, Hakan Hamid [Dept. of Pediatric Dentistry, Faculty of Dentistry, Kirikkale Unversity, Ankara (Turkmenistan); Yuksel, Selcen [Dept. of Biostatistics, Faculty of Medicine, Yildirim Beyazit University, Ankara (Turkmenistan); Ozen, Tuncer [Dept. of Dentomaxillofacial Radiology, Gulhane Military Hospital, Dental Clinics, Ankara (Turkmenistan)

    2015-12-15

    This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images.Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

  18. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

    International Nuclear Information System (INIS)

    Acar, Buket; Kamburoglu, Kivanc; Tatar, Ilkan; Arikan, Volkan; Celik, Hakan Hamid; Yuksel, Selcen; Ozen, Tuncer

    2015-01-01

    This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images.Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth

  19. Computed Tomography Imaging of the Topographical Anatomy of Canine Prostate

    International Nuclear Information System (INIS)

    Dimtrox, R.; Yonkova, P.; Vladova, D.; Kostov, D.

    2010-01-01

    AIM: To investigate the topographical anatomy of canine prostate gland by computed tomography (CT) for diagnostic imaging purposes. ÐœATERIAL AND METHODS: Seven clinically healthy mongrel male dogs at the age of 3−4 years and body weight of 10−15 kg were submitted to transverse computerized axial tomography (CAT) with cross section thickness of 5 mm. RESULTS: The CT image of canine prostate is visualized throughout the scans of the pelvis in the planes through the first sacral vertebra (S1) dorsally; the bodies of iliac bones laterally and cranially to the pelvic brim (ventrally). The body of prostate appears as an oval homogenous relatively hypo dense finding with soft tissue density. The gland is well differentiated from the adjacent soft tissues. CONCLUSION: By means of CT, the cranial part of prostate gland in adult dogs aged 3−4 years exhibited an abdominal localization. (author)

  20. Computerized detection of lacunar infarcts in brain MR images

    International Nuclear Information System (INIS)

    Uchiyama, Yoshikazu; Matsui, Atsushi; Yokoyama, Ryujiro

    2007-01-01

    Asymptomatic lacunar infarcts are often found in the Brain Dock. The presence of asymptomatic lacunar infarcts increases the risk of serious cerebral infarction. Thus, it is an important task for radiologists and/or neurosurgeons to detect asymptomatic lacunar infarctions in MRI images. However, it is difficult for radiologists and/or neurosurgeons to identify lacunar infarcts correctly in MRI images, because it is hard to distinguish between lacunar infarcts and enlarged Virchow-Robin space. Therefore, the purpose of our study was to develop a computer-aided diagnosis scheme for detection of lacunar infarctions in order to assist radiologists and/or neurosurgeons' interpretation as a ''second opinion.'' Our database consisted of 1143 T2-weighted MR images and 1143 T1-weighted MR images, which were selected from 132 patients. First, we segmented the cerebral parenchyma region by use of a region growing technique. The white-tophat transformation was then applied for enhancement of lacunar infarcts. The multiple-phase binarization was used for identifying initial candidates of lacunar infarcts. For removal of false positives (FPs), 12 features were determined in each of the initial candidates in T2 and T1-weighted MR images. The rule-based schemes and an artificial neural network with these features were used for distinguishing between lacunar infarcts and FPs. The sensitivity of detection of lacunar infarcts was 96.8% (90/93) with 0.69 (737/1063) FP per image. This computerized method may be useful for radiologists and/or neurosurgeons in detecting lacunar infracts in MRI images. (author)

  1. Computerized tomography of the brain and associated risk factors in 240 patients iwth reversible cerebral ischemic attacks (RIAs)

    International Nuclear Information System (INIS)

    Bozzao, L.; Fantozzi, L.M.; Carolei, A.; Pappata, S.; Vesentini, G.; Allori, L.; Rasura, M.; Fieschi, C.

    1985-01-01

    The frequency and distribution of focal low density cerebral ischemic lesions in RIA patients with regard to factors as age at onset, number and temporal profile of the reversible cerebral ischemic events on admission, presence of associated medical conditions such as hypertension and diabetes mellitus, have been investigated with computerized tomography of the brain. (author). 7 refs.; 1 tab

  2. Alterations found with computerized tomography in newly diagnosed type 2 diabetics

    International Nuclear Information System (INIS)

    Bruna, J.

    1989-01-01

    In 28 newly diagnosed type 2 diabetic patients (insulin-independent), computerized tomography (CT) was used to determine the density of the pancreas and the kidneys, densities of the liver, spleen and blood in the abdominal aorta, and to investigate pathological changes in the tissues mentioned above. The results were correlated with laboratory findings. The following changes were found: decreased density of the pancreas (29.4 H) and the liver (49.1 H) and increased density of the spleen (56.3 H) and blood in the abdominal aorta (43.7 H). The decreased density of the pancreas appears to be connected with disorders of lipoprotein metabolism. The decreased liver density was related to increased energy intake by food and to overweight evaluated by Broc's index. Other CT findings in the newly diagnosed type 2 diabetics (changes in the size of the pancreas, and kidneys, kidney cysts, nephrolithiasis, sclerotic plaques on aorta) were not significant. (author). 2 tabs., 11 refs

  3. Intellectual function, activities of daily living and computerized tomography of the brain in geriatric demented patients

    Energy Technology Data Exchange (ETDEWEB)

    Omura, Fumiaki; Ogura, Chikara; Kishimoto, Akira; Okubo, Masayo; Imamoto, Atsushi [Tottori Univ., Yonago (Japan). School of Medicine; Tsuchie, Harutaka; Sugihara, Kanichiro; Fujii, Shozo

    1984-09-01

    Thirty eight patients of geriatric dementia (mean age 74.9 years) were examined by computerized tomography (CT) and their intellectual functions and activities of daily living (ADL) were evaluated. CT was evaluated by both visual assessment method and direct measuring method. Intellectual function was evaluated by Jikei University dementia rating scale. ADL was evaluated by both Hasegawa's rating scale and Sengoku's rating scale. Results were as follows: significant influence by age was observed in intellectual functions and ADL of subjects above 75 years old. There were good correlations between the higher intellectual function, the better grooming and hygiene, and less needs of nursing care. The severe brain atrophy evaluated by the visual assessment method was correlated with the depressed level of intellectual function. When brain atrophy is mild despite high degree of dementia, reexamination should be made to explore somatic diseases inducing depression of mental activity. It also should be noted that sex and age difference is important in studying geriatric patients.

  4. Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

    International Nuclear Information System (INIS)

    Sondheimer, H.M.; Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

    1982-01-01

    To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease

  5. Dose evaluation in diagnostic for computerized tomography; Evaluacion de dosis en diagnostico por tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Flores, W.; Borges, J.C.; Mota, H. [Universidad Federal de Rio de Janeiro, PEN/COPPE/UFRJ. Caixa Postal 68509. 21945-970 Rio de Janeiro (Brazil)

    1998-12-31

    The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

  6. Clinical, endocrinological, and computerized tomography scans for symmetrical calcification of the basal ganglia

    International Nuclear Information System (INIS)

    Goldscheider, H.G.; Lischewski, R.; Claus, D.; Streibl, W.; Waiblinger, G.; Ulm Univ., Schwendi/Dietenbronn; Ulm Univ.

    1980-01-01

    Symmetrical calcification of the basal ganglia was found in 2 promille of 8000 computerized tomography (CT) scans. Of 19 cases, only 2 were detectable on conventional skull films. The less prominent calcifications were most often found in the region of the pallidum, the knee of the internal capsule. Also, the lesions were generally symmetrical. Thus these factors must be considered basic morphological characteristics of the pathophysiological process. Additional neurological disorders were present in 6 patients. Neurological symptoms in the remaining 13, when present, depended on the extent of the lesion. The most common finding was tremor, although disturbances of fine motor control, transient lateralizing signs, and seizures were also noted. No particular constellation of symptoms or signs permitted accurate clinical localization of the lesions. (orig./AJ) [de

  7. Computerized tomography diagnosis of cartilage destruction in carcinoma of the larynx

    International Nuclear Information System (INIS)

    Kawashima, Osamu; Tomizawa, Yoshio; Yasuoka, Yoshihito; Kamei, Tamio

    1991-01-01

    In 20 cases of laryngeal carcinoma, the pre-operative computerized tomography (CT) films were correlated with the macroscopic appearance of specimens obtained at the time of surgery. A correct diagnosis of cartilage destruction was made by pre-operative CT in 75% of cases in which the thyroid cartilage was involved and in about 79% of those with either arytenoid or cricoid cartilage involvement. A comparison between the pathological findings and the pre-operative CT findings in 9 cases of laryngeal carcinoma with destruction of the thyroid cartilage revealed several pathological changes which may lead to an incorrect CT diagnosis. These changes include microscopic infiltration; destruction of cartilage at the anterior commisure; tumor advance to sites of ossification, especially infiltration into ossifying cartilage located between two areas of non-ossifying cartilage; and infiltration of the tumor within the cartilage with preservation of the perichondrium. (author)

  8. Value of intravenous injection of contrast media for computerized tomography of the thorax

    International Nuclear Information System (INIS)

    Beyer-Enke, S.A.; Goerich, J.; Mueller, M.; Kaick, G. van; Tuengerthal, S.

    1988-01-01

    107 patients with thoracal or mediastinal growths underwent computerized tomography of the thorax both in normal condition and after receiving intravenous applications of non-ionic X-ray contrast media. The additional information obtained by use of contrast media was established in relation to the histological findings. The method led to enhanced demarcation of the tumor of the mediastinum or hilus in 40% of the patients. Tumor perfusion was helpful in 20% of the cases for differential diagnosis. Vessel infiltrations or abnormal conditions were found in about 30% of patients. 24% of the tests yielded no additional information. Analysing CT as compared to the histological examination of lymph nodes proved CT under normal conditions to be a sensitive method in 29% of cases if the hilus was the site of the tumor; contrast media raised this sensitivity to 43%. In the mediastinal area, sensitivity was 44% without and 56% with contrast media. (orig.) [de

  9. Analysis of risk in computerized tomography and other diagnostic radiology procedures

    International Nuclear Information System (INIS)

    Mossman, K.L.

    1982-01-01

    Medical practice entails continuous risks to the patient taken in good faith by the physician for the benefit of the patient. Risk of radiation induced cancer death approximates 10(-4) per cGy (rad). Assuming an average whole body dose of 0.1 cGy for many diagnostic X-ray procedures, the probability of radiation-induced cancer death is about 10(-5). The purpose of this paper is to compare the risks of common diagnostic X-ray procedures including computerized tomography (CT) with risks of smoking or automobile travel. Such comparisons should be constructive in putting radiation in perspective and facilitating explanation of risk/benefit to patients

  10. 3D observation of the solidified structures by x-ray micro computerized tomography

    International Nuclear Information System (INIS)

    Yasuda, Hideyuki; Ohnaka, Itsuo; Tsuchiyama, Akira; Nakano, Tsukasa; Uesugi, Kentaro

    2003-01-01

    The high flux density of the monochromatized and well-collimated X-ray and the high-resolution detector provide a new 3D observation tool for microstructures of metallic alloys and ceramics. The X-ray micro computerized tomography in BL47XU of SPring-8 (SP-μCT) was applied to observe microstructures produced through the eutectic reaction for Sn-based alloys and an Al 2 O 3 -Y 2 O 3 oxide system. The constituent phases in the eutectic structures were three-dimensionally identified, in which the lamellar spacing ranged from several to 10 μm. Since the 3D structure of the unidirectionally solidified specimens contains history of the eutectic structure formation, the 3D structure obtained by SP-μCT gives useful information to consider the microstructure evolution. (author)

  11. Computerized tomography of pelvic osteomyelitis in patients with spinal cord injuries

    International Nuclear Information System (INIS)

    Firooznia, H.; Rafii, M.; Golimbu, C.; Sokolow, J.

    1983-01-01

    Computerized tomography (CT) was performed in 19 patients with spinal cord injury (SCI) who had large pressure sores and in whom other complications were suspected. CT detected the depth, extent, and degree of undermining of the edges of the pressure sores in 19 of 27 lesions. Conventional radiography detected four cases of pelvic osteomyelitis. CT detected eight additional cases of pelvic osteomyelitis, as well as eight clinically unsuspected peripelvic and intrapelvic abscesses. Technetium-99m bone scanning was not very helpful because of localization in chronic proliferative changes of bone and widespread foci of myositis ossificans, as well as in osteomyelitis. Gallium-67 scanning detected only one of six abscesses. It was not very helpful because of confusion of abscess and osteomyelitis with intense soft tissue swelling and cellulitis, which are often associated with pressure sores in patients with chronic SCI. CT was found to be, by far, the modality of choice for detection of pelvic osteomyelitis and abscess in patients with SCI

  12. Quantitative computerized tomography for staging and follow up of patients with prostatic cancer

    International Nuclear Information System (INIS)

    Golimbu, C.; Golimbu, M.; Firooznia, H.; Rafii, M.; Morales, P.

    1987-01-01

    Prostate carcinoma has propensity to metastasize to skeleton, most frequently affecting the lumbar spine. The isotope bone scan and serum prostatic acid phosphatase (PAP) have been considered most reliable in documenting cancer spread. However, the former has been shown to have low specificity, and the latter was found to be increased in patients with localized disease or normal in patients with proven metastases. In a previous study of a group of patients at risk of having metastatic bone involvement, albeit not revealed by standard methods, the authors demonstrated the ability of quantitative computerized tomography (QCT) to depict early stages of bone metastases (Golimbu et. al., 1986). They also demonstrated its usefulness in assessing the response to treatment. The authors extended their study to further evaluate the accuracy of QCT in comparison with Tc99m bone scan and serum PAP for early detection of bone metastases and for quantitation of metastatic bone lesions response to therapy

  13. Muscle area and muscle density of osteoarthritis of the knee joint studied by computerized tomography

    International Nuclear Information System (INIS)

    Suzuki, Nobuharu; Onosawa, Toshihiro; Shibata, Minoru; Yamashita, Izumi; Yoshimura, Shinichiro; Muraoka, Shunichi; Asano, Akira

    1985-01-01

    In order to investigate the etiology and pathology of osteoarthritis of the knee joints (OA), the areas and density of the muscle 10 cm above the knee were compared using computerized tomography (CT) in 26 knees from 19 normal persons, 30 knees from 17 patients with OA, and 14 knees from 7 patients with rheumatoid arthritis. The areas of the quadriceps musculi of thigh were remarkably decreased and the areas of the flexor musculi were comparatively maintained in the patients with OA. Muscle density was markedly lowered in the musculi semimembranosus and biceps femoris long head. Fatty tissues were seen in the whole area of the venter on CT in some of the patients with OA. These findings are considered to be of major importance when studying the etiology of OA. (Namekawa, K.)

  14. Spiral Computed Tomographic Imaging Related to Computerized Ultrasonographic Images of Carotid Plaque Morphology and Histology

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise M.; Wagner, Aase; Wiebe, Britt M.

    2001-01-01

    Echolucency of carotid atherosclerotic plaques, as evaluated by computerized B-mode ultrasonographic images, has been associated with an increased incidence of brain infarcts on cerebral computed tomographic scans. We tested the hypotheses that characterization of carotid plaques on spiral comput...

  15. Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography

    International Nuclear Information System (INIS)

    Lucarelli, Claudio Luiz

    1995-01-01

    The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

  16. Clinical evaluation of 99mTc-CPI myocardial perfusion single photon emission computerized tomography in the diagnosis of coronary heart disease

    International Nuclear Information System (INIS)

    Peng Changping

    1991-01-01

    Two normal subjects, 5 patients with old myocardial infarction (OMI) and 4 patients with angina pectoris were examined by rest single photon emission computerized tomography revealed that the right ventricular was not imaged, the left ventricular was well exposed in the normal subjects. All the 9 patients had defects in the left ventricle. comparison of SPECT with 99m Tc-CPI with selective coronary arteriography (SCA), echocardiography (UCG), dynamic electrocardiography (DCG) and electrocardiographic (ECG)-exercise test in the diagnosis of myocardial ischemia or necrosis has demonstrated the former to be more significantly sensitive than the latter four. Good agreement between SPECT and SCA has been confirmed

  17. Computed tomography and three-dimensional imaging

    International Nuclear Information System (INIS)

    Harris, L.D.; Ritman, E.L.; Robb, R.A.

    1987-01-01

    Presented here is a brief introduction to two-, three-, and four-dimensional computed tomography. More detailed descriptions of the mathematics of reconstruction and of CT scanner operation are presented elsewhere. The complementary tomographic imaging methods of single-photon-emission tomography (SPECT) positron-emission tomography (PET), nuclear magnetic resonance (NMR) imaging, ulltrasound sector scanning, and ulltrasound computer-assisted tomography [UCAT] are only named here. Each imaging modality ''probes'' the body with a different energy form, yielding unique and useful information about tomographic sections through the body

  18. Diagnostic radiology for head and neck neoplasms with emphasis on computerized tomography

    International Nuclear Information System (INIS)

    Weber, A.L.; Manzione, J.V.

    1986-01-01

    The radiologic evaluation of head and neck neoplasms constitutes an important part in their diagnosis and treatment. The introduction of computerized tomography (CT) and the further development of this modality since 1972 have contributed significantly to the staging of these neoplasms. CT not only demonstrates soft tissue densities, but also bony structures, muscles, fascial planes, opacified vascular structures, and enlarged lymph nodes. CT, however, fails to differentiate the various histologic types of lesions in the majority of cases. Features such as size of the lesion, marginal definition, lytic bone destruction, sclerotic bony reaction, bony expansion, calcific densities, fat content, and obliteration of fascial planes are utilized to delimit the spectrum of diagnostic possibilities. Conventional films including tomography are also indicated as preliminary examinations in the investigation of head and neck neoplasms. They provide a survey of the abnormality in question and form the basis for special studies such as CT and angiography. They are often the first examination to demonstrate a lesion that may be suspected from the history and clinical examination. 13 refs.; 11 figs

  19. Transection of the pituitary stalk: evaluation of two cases by computerized tomography and magnetic resonance

    International Nuclear Information System (INIS)

    Amaral, L.L.F. do; Mendonca, R.A.; Natal, M.R.C.

    1992-01-01

    The authors present two cases of pituitary dwarfism where the study by high resolution computed tomography and by magnetic resonance imaging show transection of the pituitary stalk as the cause of the endocrine disturb. The importance of these methods on the investigation of disturbs of the hypothalamus-hypophyseal axis is stressed. (author)

  20. Computerized comprehensive data analysis of Lung Imaging Database Consortium (LIDC)

    International Nuclear Information System (INIS)

    Tan Jun; Pu Jiantao; Zheng Bin; Wang Xingwei; Leader, Joseph K.

    2010-01-01

    Purpose: Lung Image Database Consortium (LIDC) is the largest public CT image database of lung nodules. In this study, the authors present a comprehensive and the most updated analysis of this dynamically growing database under the help of a computerized tool, aiming to assist researchers to optimally use this database for lung cancer related investigations. Methods: The authors developed a computer scheme to automatically match the nodule outlines marked manually by radiologists on CT images. A large variety of characteristics regarding the annotated nodules in the database including volume, spiculation level, elongation, interobserver variability, as well as the intersection of delineated nodule voxels and overlapping ratio between the same nodules marked by different radiologists are automatically calculated and summarized. The scheme was applied to analyze all 157 examinations with complete annotation data currently available in LIDC dataset. Results: The scheme summarizes the statistical distributions of the abovementioned geometric and diagnosis features. Among the 391 nodules, (1) 365 (93.35%) have principal axis length ≤20 mm; (2) 120, 75, 76, and 120 were marked by one, two, three, and four radiologists, respectively; and (3) 122 (32.48%) have the maximum volume overlapping ratios ≥80% for the delineations of two radiologists, while 198 (50.64%) have the maximum volume overlapping ratios <60%. The results also showed that 72.89% of the nodules were assessed with malignancy score between 2 and 4, and only 7.93% of these nodules were considered as severely malignant (malignancy ≥4). Conclusions: This study demonstrates that LIDC contains examinations covering a diverse distribution of nodule characteristics and it can be a useful resource to assess the performance of the nodule detection and/or segmentation schemes.

  1. Imaging granulomatous lesions with optical coherence tomography

    DEFF Research Database (Denmark)

    Banzhaf, Christina; Jemec, Gregor B E

    2012-01-01

    To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors.......To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors....

  2. Study of noise sources of image for optimization of radiation doses in skull computerized tomography; Estudo das fontes de ruido da imagem para fins de otimizacao das doses na tomografia computadorizada de cranio

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, R.B.; Garos, K.A.C. [UNIFESP - Universidade Federal de Sao Paulo, SP (Brazil)]. E-mail: rbitelli@cfrh.epm.br

    2001-07-01

    Our goal was to evaluate the exposure factors that can change the image noise of head CT in different slices thicknesses. We have evaluated the images noise at several mAs varying from 50 to 800 mAs for 100, 120 and 140 kVp as tension values. The images uniformity were determined for all technical exposure conditions. We did not observed any important noise reduction for values up 200 mAs which can justify the increase of radiation doses through the increase of mAs. (author)

  3. Evaluation of dosimetric techniques in positrons emission tomography and computerized tomography (PET/CT)

    International Nuclear Information System (INIS)

    Pinto, Gabriella Montezano

    2014-01-01

    Among diagnostic techniques PET/CT is one of those with the highest dose delivery to the patient as a cause of external exposure to X-rays, and the use of a radiopharmaceutical that results in a high energy gamma emission. The dosimetry of these two components becomes important in order to optimize and justify the technique. Various dosimetric techniques are found in literature without a consensus of the best to use. With the advances in technological and consequent equipment configuration changes, upgrades and variation in methodologies, particularly in computed tomography, a standardization of these techniques is required. Previous studies show that CT is responsible for 70 % of the dose delivered to the patient in PET/CT examinations. Thus, many researchers have been focused on CT dose optimization protocols studies. This work analyzes the doses involved in a PET/CT oncology protocol by using an Alderson female anthropomorphic phantom in a public hospital of Rio de Janeiro city. The dose estimate for PET examination resulting from the use of 18 F - FDG radiopharmaceutical was conducted through dose factors published in ICRP 106; the dose for CT was estimated and compared by calculation of the absorbed doses to patients according to four methods: thermoluminescent dosimetry (TL0100) distributed in critical organs of the Alderson phantom; measurements of CTOI according to AAPM number 96; correction factor for effective diameter SSOE (AAPM Number 204); and simulation by ImPACT program For CT, the results in terms of effective dose presented (TLO, CTOI and ImPACT) ± 5 % maximum variations between methodologies. Considering medium absorbed dose (TLO, SSOE and ImPACT) the results differed in ± 7 % from each other. These findings demonstrate that parameters provided by the manufacturer on the console can be used to have a primary approach of both, absorbed and effective doses to the patient since that a quality assurance program of these parameters are adopted in

  4. High-resolution nuclear magnetic resonance imaging and single photon emission computerized tomography--cerebral blood flow in a case of pure sensory stroke and mild dementia owing to subcortical arteriosclerotic encephalopathy (Binswanger's disease)

    DEFF Research Database (Denmark)

    De Chiara, S; Lassen, N A; Andersen, A R

    1987-01-01

    hypertensive, 72-year-old patient with PSS, CT scanning and conventional nuclear magnetic resonance imaging (NMRI) scanning using a 7-mm-thick slice on a 1.5 Tesla instrument all failed to visualize the thalamic infarct. Using the high-resolution mode with 2-mm slice thickness it was, however, clearly seen...

  5. ECAT: a new computerized tomographic imaging system for position-emitting radiopharmaceuticals

    International Nuclear Information System (INIS)

    Phelps, M.E.; Hoffman, E.J.; Huang, S.C.; Kuhl, D.E.

    1977-01-01

    The ECAT was designed and developed as a complete computerized positron radionuclide imaging system capable of providing high contrast, high resolution, quantitative images in 2 dimensional and tomographic formats. Flexibility, in its various image mode options, allows it to be used for a wide variety of imaging problems

  6. Quality of computerized tomography exams proposed by a quality certification program

    International Nuclear Information System (INIS)

    Carlos, Marcia Terezinha

    1999-01-01

    Brazilian College of Radiologists (CBR) is concerned about the quality of radiological practices in the country. Actions in direction of accreditation programmes and standardization of the performance in imaging modalities have been implemented. The first accreditation programme was in mammography. In Brazil, computed tomography spread all over the country. Due high radiation dose to the patient and the continuous technological development, an accreditation programme in CT practice is necessary. A pilot programme has been carried out in the area of Rio de Janeiro with the participation of 11 CT facilities with 12 CT units. The background information follows Document EUR 16262 E uropean Guidelines of Quality Criteria for Computed Tomography . Initially practice data were collected through structured interviews using a standardized questionnaire. In regard to the assessment of clinical image quality, two examinations were selected: brain general and abdomen general. Three radiologists specialized in computed tomography evaluated the image quality criteria from a sample of examinations from the participant facilities. Other aspects selected to the assessment of the overall performance are: technical parameters of the examinations; image physical parameters (noise, spatial resolution, sensitivity profile) and radiation dose. Radiation dose and image quality criteria were fulfilled by 7 of 12 brain general examinations analyzed and only 5 of 10 abdomen general examinations analyzed. At the moment, it was not possible to get a conclusion about image quality based on measurements of physical parameters. Other factors affecting overall image quality were: technical limitation of CT units and practitioners are not able to fully handle the technical parameters of the examination. Dose and image quality criteria shall be the basis of an accreditation programme in CT and Brazilian College of Radiology has to use the experience of this work to implement a programme at national

  7. Computerized tomography findings in Fahr's syndrome Achados da tomografia computadorizada na síndrome de Fahr

    Directory of Open Access Journals (Sweden)

    Andréia V. Faria

    2004-09-01

    Full Text Available We analyzed computerized tomography (CT findings in six patients with Fahr's syndrome. They presented calcifications in basal ganglia, dentate nucleus, subcortical region and semioval center, due to alteration in calcium metabolism or due to senile relative hypoxemic state. The image pattern was not strictly related with etiology, although some differences in dystrophic senile calcifications (the only one present in semioval center and absent in subcortical region. CT is an easy exam, has maximum sensitivity and allows diagnosis, contributing to early treatment of many etiologies of Fahr's syndrome.Analisamos os achados de tomografia computadorizada (TC de seis pacientes com síndrome de Fahr. Eles apresentaram calcificações nos gânglios da base, núcleo denteado, região subcortical e centro semi-oval, devidas a distúrbios no metabolismo do cálcio ou a estado de hipóxia relativa, por senilidade. O padrão de imagem não apresenta relação clara com a etiologia, apesar de algumas diferenças no caso das calcificações distróficas senis (as únicas presentes nos centros semi-ovais e ausentes na região subcortical. TC é um exame de fácil realização, máxima sensibilidade e permite o diagnóstico, contribuindo para o tratamento precoce de muitas das etiologias da síndrome de Fahr.

  8. Computerized tomography with 3-dimensional reconstruction for the evaluation of renal size and arterial anatomy in the living kidney donor.

    Science.gov (United States)

    Janoff, Daniel M; Davol, Patrick; Hazzard, James; Lemmers, Michael J; Paduch, Darius A; Barry, John M

    2004-01-01

    Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes. Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions. The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%. CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

  9. A study of the imaging of atomic elements by computerised axial tomography

    OpenAIRE

    McCarthy, K. J

    1989-01-01

    Conventional computerized axial tomography images show the spatial variation in the linear attenuation coefficient in a cross-section of a specimen. However, no information is present to enable one to predict the location nor concentration of an atomic element in the image. Differential X-ray absorptiometry is a well established analytic technique for determining the concentration of an atomic element in a specimen. In this thesis, it is shown that by applying differential X-ray absorpt...

  10. Positron emission tomography imaging of gene expression

    International Nuclear Information System (INIS)

    Tang Ganghua

    2001-01-01

    The merging of molecular biology and nuclear medicine is developed into molecular nuclear medicine. Positron emission tomography (PET) of gene expression in molecular nuclear medicine has become an attractive area. Positron emission tomography imaging gene expression includes the antisense PET imaging and the reporter gene PET imaging. It is likely that the antisense PET imaging will lag behind the reporter gene PET imaging because of the numerous issues that have not yet to be resolved with this approach. The reporter gene PET imaging has wide application into animal experimental research and human applications of this approach will likely be reported soon

  11. Value of computerized tomography in the diagnosis of bone and musculoskeletal system tumors of the pelvis and extremities

    International Nuclear Information System (INIS)

    Langer, R.; Langer, M.

    1983-01-01

    49 cases of tumors of the musculoskeletal system of the pelvis and the extremities have been investigated by computerized tomography. The CT was performed only after conventional radiologic methods. The results are discussed and compared with those described in the literature. The advantages and disadvantages of CT of musculoskeletal disorders are discussed. We consider the CT to be of value in disorders of the musculoskeletal system, specially, if operative- or radiotherapy is planned. (orig.) [de

  12. Comparative evaluations of the results of common X-ray examinations and computerized tomography in patients with exogenous allergic alveolitis

    International Nuclear Information System (INIS)

    Khomenko, A.G.; Dmitrieva, L.I.; Khikkel', Kh.G.; Myuller, S.

    1989-01-01

    A correlative study of the results of x-ray examination using routine methods and computerized tomography (CT) was conducted to specify the roentgenomorphological substrate of changes in patients with exogenous allergic alveolitis. The established complex of routine methods is informative enough to interpret the revealed changes. However, at early stages CT helps to specify semiotics and permits obtaining additional information, particularly on quantitative, i.e. densitometric changes. In diffuse and disseminated pulmonary lesions CT can be used as an additional method

  13. Evaluation of parapharyngeal space by computerized tomography and magnetic resonance. Part 1: anatomy

    International Nuclear Information System (INIS)

    Souza, Ricardo Pires de; Rapoport, Abrao

    1994-01-01

    The authors, through a comprehensive review of the literature, intend to establish an anatomical concept of the parapharyngeal space and its surroundings spaces in the supra-hyoid neck, based on its division by the fascial planes. The correlation between the anatomically defined parapharyngeal space and the findings of the sectional imaging procedures (computed tomography and magnetic resonance) is established, evidencing clear anatomic-radiologic correspondence. (author)

  14. Value of computerized tomography in the diagnosis of primary and recurrent pituitary gland tumors

    International Nuclear Information System (INIS)

    Imhof, H.; Kuester, W.; Eslami-Nejad, S.

    1979-01-01

    The results of cranial computerized tomography (CCT) of 33 patients with questionable space-occupying lesions in the sella-region are compared with clinical, radiological and surgical reports. Five pituitary gland tumors could be detected for the first time. Four of them are verified by surgery. In eight cases recurrent pituitary glant tumors are suspected. Surprisingly these tumors could be found by surgery only in three cases, while in the remaining five cases only scar-tissue was demonstrable. The high accuracy of CCT in the detection of pituitary gland tumors and the possibility to save the patient expensive and high invasive examinations as well, makes CCT in the presence of corresponding clinical signs to a diagnostic 'must'. It is undecided whether in the cases with possible recurrent tumors, there are real recurrent tumors, which could not be detected by surgery, or only scar tissue. In the latter case scar tissue and recurrent pituitary gland tumors are very similar with CCT. (orig.) 891 MG/orig. 892 CKA [de

  15. Measurement on the density resolution of industrial computerized tomography by using disc specimen with holes

    International Nuclear Information System (INIS)

    Tian, Y.; Gao, D.; Zhang, W.; Xia, Z.; Yang, C.

    2004-01-01

    Several ways mainly used for measuring the density resolution of industrial computerized tomography (ICT) are briefly introduced. Based on the equivalent conversion between volume variation and density variation, a kind of disc specimen with holes is designed to measure the density resolution of ICT. In this experiment, a kind of high quality polymethyl methacylate (PMMA) is selected to make specimens with diameter of 250mm, in which six sets of holes with diameter separately 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm are distributed in the radial directions with interval of 60 o between two neighboring sets, and in the same set, the distances of holes departing the center of the specimen are respectively 20mm, 40mm, 60mm, 80mm, and 100mm. The experiment shows that the method is sensitive, simple, flexible, and practical. About 0.2% density resolution of region of interest (ROI) with diameter 20mm can be verified, the relationship between CT value of ROI and its position can be obtained, and at the same time the spatial resolution of ICT can be measured in high quality. (author)

  16. Indirect computerized tomography sign of chronic subdural hematoma demonstrated in the posterior fossa

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Takao; Fukui, Masashi; Maeyama, Ryutaro; Takaki, Tosuke; Yoshiura, Shogo; Kamoi, Itsuma

    1985-03-01

    In cases of chronic subdural hematoma (CSH), brain computerized tomography (CT) scans frequently disclose a low density band in the posterior fossa (LDBP) between the lateral margin of the cerebellum and the adjacent petrous bone/tentorium cerebelli. Out of 121 cases of CSH, 56 (46%) showed the LDBP. The LDBP was mostly ipsilateral to the side of the CSH or bilateral. The frequency of the LDBP had no correlation with the severity of the cerebral midline shift or the thickness of the hematoma. As normal controls, CT scans of 257 cases in which no organic lesions were detected were used. Also 30 cases with dementing diseases, 2 cases with spinocerebellar degeneration and 428 cases of other neurological diseases such as head trauma other than CSH, brain tumor, cerebrovascular disease etc. were studied as disease controls. The incidence of the LDBP in both controls was significantly lower than in CSH. Therefore, the LDBP in cases of CSH was considered to be a significant associated finding of CT scans. The mechanism of the LDBP is discussed.

  17. Computerized tomography of the otic capsule and otoliths in the oyster toadfish, Opsanus tau.

    Science.gov (United States)

    Edds-Walton, Peggy L; Arruda, Julie; Fay, Richard R; Ketten, Darlene R

    2015-02-01

    The neurocranium of the toadfish (Opsanus tau) exhibits a distinct translucent region in the otic capsule (OC) that may have functional significance for the auditory pathway. This study used ultrahigh resolution computerized tomography (100 µm voxels) to compare the relative density of three sites along the OC (dorsolateral, midlateral, and ventromedial) and two reference sites (dorsal: supraoccipital crest; ventral: parasphenoid bone) in the neurocranium. Higher attenuation occurs where structural density is greater; thus, we compared the X-ray attenuations measured, which provided a measure of relative density. The maximum attenuation value was recorded for each of the five sites (x and y) on consecutive sections throughout the OC and for each of the three calcareous otoliths associated with the sensory maculae (lagena, saccule, and utricle) in the OC. All three otoliths had higher attenuations than any sites in the neurocranium. Both dorsal and ventral reference sites (supraoccipital crest and parasphenoid bone, respectively) had attenuation levels consistent with calcified bone and had relatively small, irregular variations along the length of the OC in all individuals. The lowest relative attenuations (lowest densities) occurred consistently at the three sites along the OC. In addition, the lowest attenuations measured along the OC occurred at the ventromedial site around the saccular otolith for all seven fish. The decrease in bone density along the OC is consistent with the hypothesis that there is a low-density channel in the skull to facilitate transmission of acoustic stimuli to the auditory endorgans of the ear. © 2014 Wiley Periodicals, Inc.

  18. Correlations between computerized tomography of the head and motor developmental disturbances of children with cerebral palsy

    International Nuclear Information System (INIS)

    Chen, Yu-Herng

    1981-01-01

    Two hundred and eighty-two children with cerebral palsy (C.P.) and thirty-seven normal children were studied by computerized tomography (C.T.) of the head for finding out the correlations between the organic damage of the brain and the motor developmental disturbance. The abnormal findings of C.T. were: enlargement of the ventricular system, high density area, low density area and porencephalus, enlargement of the sulcus and anomaly of the medial structure. Enlargement of the ventricular system seemed to have correlation with spasticity; the portion and the extent of the enlargement corresponded to the affected extremities and the severity of the spasticity. Children of other types also showed various abnormal C.T. findings but, in general, less than that of spastic types. The prognosis of the motor development of C.P. children cannot be predicted by serial C.T. examinations strictly, because early treatment could cause improvement to that of these children. However, it is of worthy notice that C.T. is an effective method of helping to diagnose the motor developmental disturbance in earlier childhood. (author)

  19. Pathogenesis of traumatic intracerebral hematoma with a sequential study of computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ohmori, H; Miyazaki, S; Munekata, K; Fukushima, H [Hitachi General Hospital, Hitachi, Ibaraki (Japan); Shohji, A

    1981-04-01

    A sequential study with computerized tomography (CT scan) of two cases of traumatic intracerebral hematoma is reported. Case 1 was a 69-year-old man who had a head injury. The initial CT scan, taken 1 hour after his injury, showed a left temporal salt-and-pepper appearance, which proved to be a cerebral contusion. The CT scan 4.5 hours after his injury showed a left temporal high density area instead. An operation was performed, and a massive intracerebral hematoma was observed. Case 2 was a 61-year-old man who was also admitted because of a head injury. The initial CT scan, taken 1 hour after his injury, revealed several bifrontal intracerebral hemorrhagic spots in the low-density areas, suggesting contusion. A secondary CT scan (23 hours) demonstrated that the traumatic intracerebral hematoma had developed into a posttraumatic cerebral contusion. The operation disclosed a hematoma surrounded by contusion. These cases prove that traumatic intracerebral hematoma is often caused by cerebral contusion.

  20. Contribution of computerized tomography and nuclear magnetic resonance to the diagnosis of vascular dementia

    Energy Technology Data Exchange (ETDEWEB)

    Gallois, P; Pruvo, J P

    1987-06-18

    Nuclear magnetic resonance (NMR) and computerized tomography (CT) have become indispensable to the exploration of patients with vascular dementia. NMR is remarkable for its innocuity, its anatomical accuracy, its sensitivity and the three-dimensional approach it offers. CT is less sensitive, but the examinations are shorter and less costly. These two techniques seem to be about equally effective in visualizing multiple infarcts, although NMR gives a better contrast. In dementia due to multiple infarcts, the bilateral cortical and subcortical lesions coexist with moderate cortical atrophy. The cerebral lacunae of lacunar dementia are better visualized by NMR; they are distributed on both sides, predominate in the frontal lobes and only produce slight cortical atrophy, less pronounced than ventricular dilatation. The main advantage of NMR is its high sensitivity in detecting early changes in the white matter, changes which are particularly perceptible in juxta- and peri-ventricular areas in arteriosclerous subcortical leucoencephalopathy. NMR, not very specific here, does not readily separate these lesions from those of other types of leucoencephalopathy. The finding of hypodense areas at CT or hypersignals at NMR (T2) around the ventricles may help in differentiating between vascular dementia, irrespective of its mechanism, and primary dementia.

  1. Evaluation for computerized axial tomography to three anthropomorphic methods to estimate the thigh muscle area

    International Nuclear Information System (INIS)

    Fernandez Vieitez, Jorge Alberto; Alvarez Cuesta, Jose Alberto; Williams Wilson, Luis

    2001-01-01

    Three anthropometric methods to estimate the thigh muscle area (TMA, cm) were evaluated. Seventeen young males were taken as a sample. The TMA was estimated by using the formulas of Gurney-Jellife, Jones-Pearson, Housh, and others. In the same place where the measurements of circumferences and skinfolds were made, the TAM was determined by computerized axial tomography. It was used as a reference criterion with which the anthropometric values were compared. The methods of Gurney-Jellife and Jones-Pearson significantly overestimated the TAM obtained by CAT (9.0 + - 12.8 cm 2 [4.4 %]; p = 0.01 and 22.0 + - 14.9 cm 2 [10.9 %]; p = 1.6 . 10-5, respectively), whereas that of Housh and others underestimated the values of CAT (-48.8 + - 11.7 cm 2 [24.1 %]; p = 9.4 . 10-12). The Gurney-Jellife equation was the only one that proved to be interchangeable with CAT, on obtaining a coefficient of correlation (r) and a slope of regression (b) for the difference and the average between both methods that were not statistically significant (r 0,421; b = 0,21 + - 0.12, p = 0.09). It was concluded that of the 3 studied anthropometric methods, the Gurney-Jellife method offers the most accurate TAM values

  2. Imagenological characterization by Computerized Axial Tomography of the primary intracranial tumors

    International Nuclear Information System (INIS)

    Sosa Rivera, Manuel; Quintas Santana, Maria

    2009-01-01

    A descriptive observational study to 56 patients with imagenological diagnosis of primary intracranial neoplasia attended in the service of imagenology of the Provincial Docent Hospital 'Dr. Antonio Luaces Iraola' was carried out from March 1st 2006 to February 1st 2008, with the aim of characterizing these injuries by Computerized Axial Tomography and establishing an evaluation with the histological diagnosis. A questionnaire with the following variables was applied: sex, presuntive age, clinic, topographical characteristics (location, size, tumoral density, changes with administration of the resistance, calcifications, effect of mass and evaluation of the imagenological diagnosis with the histological diagnosis. Masculine sex and the group of ages of 60 are more predominated. The more frequent clinical manifestations were migraine, convulsions, difficulty to walk and vertigo. The size of the injury that prevailed was of 5, 9 and 2, 1 cm with supratentorial location. The majority of primary intracranial neoplasms were hypodense, and enhancement of the injuries with the administration of the resistance was observed. The mass effect bears a close relation with the location and size of the injury. The imagenological diagnosis fitted in with the histological one, being the gliomas the more frequent histological type

  3. On the pathogenesis of traumatic intracerebral hematoma with a sequential study of computerized tomography

    International Nuclear Information System (INIS)

    Ohmori, Hidetoshi; Miyazaki, Shinichiro; Munekata, Katsuharu; Fukushima, Hiromi; Shohji, Akira.

    1981-01-01

    A sequential study with computerized tomography (CT scan) of two cases of traumatic intracerebral hematoma is reported. Case 1 was a 69-year-old man who had a head injury. The initial CT scan, taken 1 hour after his injury, showed a left temporal salt-and-pepper appearance, which proved to be a cerebral contusion. The CT scan 4.5 hours after his injury showed a left temporal high density area instead. An operation was performed, and a massive intracerebral hematoma was observed. Case 2 was a 61-year-old man who was also admitted because of a head injury. The initial CT scan, taken 1 hour after his injury, revealed several bifrontal intracerebral hemorrhagic spots in the low-density areas, suggesting contusion. A secondary CT scan (23 hours) demonstrated that the traumatic intracerebral hematoma had developed into a posttraumatic cerebral contusion. The operation disclosed a hematoma surrounded by contusion. These cases prove that traumatic intracerebral hematoma is often caused by cerebral contusion. (author)

  4. The radiologic finding in pneumomediastinum. Value of conventional radiography and comparison with computerized tomography

    International Nuclear Information System (INIS)

    Martin, M.F.; Hlawatsch, A.; Heussel, C.P.; Schweden, F.; Kauczor, H.U.

    1997-01-01

    Pneumomediastinum, or mediastinal emphysema, may be difficult to demonstrate and is not always easy to differentiate from pneumothorax and pneumopericardium by conventional radiography, especially in severely ill patients. In this article, we evaluate the sensitivity of plain films in detecting pneumomediastinum, and describe the conventional radiography and computerized tomography (CT) findings associated with this entity. The etiology and CT findings in 24 patients who had been diagnosed as having pneumomediastinum by CT were reviewed. Conventional radiographs were available for review in 19 of these cases. Radiographic and CT findings were retrospectively compared, using CT as reference technique. We looked for abnormal mediastinal air collections and their location, as well as pathologic findings such as pneumothorax or pneumopericardium. Classical radiographic signs were also evaluated. Conventional radiography showed mediastinal air in 17 patients (89,5%) and classical radiographic signs were observed in 13 (68,4%). The results of the comparative study of plain films and CT revealed the following sites of mediastinal air: superior mediastinum (9/15), anterior mediastinum (14/19), middle mediastinum (7/12) and posterior mediastinum (4/14). The incidences of pneumothorax (7/12) and pneumopericardium (1/4) were also recorded. The comparative study of conventional radiography and CT demonstrated that Ct is a more reliable technique for determining the diagnosis, location and extent of pneumomediastinum and differentiating it from pneumothorax and pneumopericardium, especially in severely ill patients. Therefore, CT is recommended in patients with evident clinical suspicion of pneumomediastinum. (Author) 23 refs

  5. Intellectual function, activities of daily living and computerized tomography of the brain in geriatric demented patients

    International Nuclear Information System (INIS)

    Omura, Fumiaki; Ogura, Chikara; Kishimoto, Akira; Okubo, Masayo; Imamoto, Atsushi; Tsuchie, Harutaka; Sugihara, Kanichiro; Fujii, Shozo.

    1984-01-01

    Thirty eight patients of geriatric dementia (mean age 74.9 years) were examined by computerized tomography (CT) and their intellectual functions and activities of daily living (ADL) were evaluated. CT was evaluated by both visual assessment method and direct measuring method. Intellectual function was evaluated by Jikei University dementia rating scale. ADL was evaluated by both Hasegawa's rating scale and Sengoku's rating scale. Results were as follows: significant influence by age was observed in intellectual functions and ADL of subjects above 75 years old. There were good correlations between the higher intellectual function, the better grooming and hygiene, and less needs of nursing care. The severe brain atrophy evaluated by the visual assessment method was correlated with the depressed level of intellectual function. When brain atrophy is mild despite high degree of dementia, reexamination should be made to explore somatic diseases inducing depression of mental activity. It also should be noted that sex and age difference is important in studying geriatric patients. (author)

  6. A Computerized Tomography Study of Vocal Tract Setting in Hyperfunctional Dysphonia and in Belting.

    Science.gov (United States)

    Saldias, Marcelo; Guzman, Marco; Miranda, Gonzalo; Laukkanen, Anne-Maria

    2018-04-03

    Vocal tract setting in hyperfunctional patients is characterized by a high larynx and narrowing of the epilaryngeal and pharyngeal region. Similar observations have been made for various singing styles, eg, belting. The voice quality in belting has been described to be loud, speech like, and high pitched. It is also often described as sounding "pressed" or "tense". The above mentioned has led to the hypothesis that belting may be strenuous to the vocal folds. However, singers and teachers of belting do not regard belting as particularly strenuous. This study investigates possible similarities and differences between hyperfunctional voice production and belting. This study concerns vocal tract setting. Four male patients with hyperfunctional dysphonia and one male contemporary commercial music singer were registered with computerized tomography while phonating on [a:] in their habitual speaking pitch. Additionally, the singer used the pitch G4 in belting. The scannings were studied in sagittal and transversal dimensions by measuring lengths, widths, and areas. Various similarities were found between belting and hyperfunction: high vertical larynx position, small hypopharyngeal width, and epilaryngeal outlet. On the other hand, belting differed from dysphonia (in addition to higher pitch) by a wider lip and jaw opening, and larger volumes of the oral cavity. Belting takes advantage of "megaphone shape" of the vocal tract. Future studies should focus on modeling and simulation to address sound energy transfer. Also, they should consider aerodynamic variables and vocal fold vibration to evaluate the "price of decibels" in these phonation types. Copyright © 2018. Published by Elsevier Inc.

  7. Computerized tomography and pulmonary diffusing capacity in highly trained athletes after performing a triathlon.

    Science.gov (United States)

    Caillaud, C; Serre-Cousiné, O; Anselme, F; Capdevilla, X; Préfaut, C

    1995-10-01

    We investigated the computerized tomographies (CTs) of the thorax and the pulmonary diffusing capacity for CO (DLCO) in eight male athletes before and after a triathlon. DLCO and alveolar volume (VA) were simultaneously measured during 9 s of breath holding. The transfer coefficient (KCO = DLCO/VA) was then calculated. CT scanning was performed during breath holding with the subjects in the supine position. Scanner analysis was done by 1) counting the linear and polygonal opacities (index of interstitial fluid accumulation) and 2) calculating the physical mean lung density and the mean slice mass. Results showed a significant reduction in DLCO (44.9 +/- 2.3 vs. 42.9 +/- 1.7 ml.min-1.mmHg-1; P triathlon and an increase in mean lung density (0.21 +/- 0.009 vs. 0.25 +/- 0.01 g/cm3; P long-distance race and showed a concomitant increase in CT lung density and in the number of opacities.

  8. Basilar expansion of the human sphenoidal sinus: an integrated anatomical and computerized tomography study

    International Nuclear Information System (INIS)

    Haetinger, Rainer G.; Navarro, Joao A.C.; Liberti, Edson A.

    2006-01-01

    Basilar expansion of the sphenoidal sinus (BESS) was studied in order to demonstrate its critical relevance in endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. Direct evaluation of anatomical specimens (25 dry skulls and 25 formalin-fixed hemi heads) and the use of computerized tomography (CT) (50 dry skulls and 750 patients) showed a high BESS frequency (69%). The authors considered BESS to be critical when the posterior wall of the clivus was 2-mm thick and found a high incidence of this important anatomical variation (44%). This study also evaluated the relationship between the sinonasal septa, the clivus, and the internal carotid arteries, and a considerable regularity in the location of these structures was seen. The septa were anatomically related to the internal carotid arteries in 55% and to the clivus in 33% of the cases. In conclusion, the high frequency of critical BESS here described is relevant to endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. (orig.)

  9. Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Biscaldi, Ennio, E-mail: ennio.biscaldi@gmail.com [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy); Ferrero, Simone, E-mail: simone.ferrero@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Leone Roberti Maggiore, Umberto, E-mail: ulrm@libero.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Remorgida, Valentino, E-mail: vremorgida@yahoo.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Venturini, Pier Luigi, E-mail: venturini@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Rollandi, Gian Andrea, E-mail: rollandi@galliera.it [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy)

    2014-02-15

    Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis.

  10. Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

    International Nuclear Information System (INIS)

    Biscaldi, Ennio; Ferrero, Simone; Leone Roberti Maggiore, Umberto; Remorgida, Valentino; Venturini, Pier Luigi; Rollandi, Gian Andrea

    2014-01-01

    Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis

  11. Pseudomeningocele in communication with the facet joint: demonstration by computerized tomography-arthrography

    International Nuclear Information System (INIS)

    Ganiyusufoglu, Kursat; Ozturk, Cagatay; Sirvanci, Mustafa; Aksu, Neslihan; Hamzaoglu, Azmi

    2008-01-01

    Pseudomeningocele is an uncommon but well-known complication of lumbar spine operations. Although it is mostly asymptomatic and managed conservatively in most cases, it is claimed as a causative factor of failed back surgery syndrome and requires surgery in some cases. Usually, its diagnosis is confidently done with imaging modalities such as magnetic resonance imaging, computed tomography and myelography. In this report, we describe a case of pseudomeningocele that communicated with a facet joint. The diagnostic approach for this unusual lesion and its probable causes are discussed. (orig.)

  12. Pseudomeningocele in communication with the facet joint: demonstration by computerized tomography-arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Ganiyusufoglu, Kursat; Ozturk, Cagatay; Sirvanci, Mustafa; Aksu, Neslihan; Hamzaoglu, Azmi [Florence Nightingale Hospital, Istanbul Bilim University, Istanbul Spine Center, Istanbul (Turkey)

    2008-08-15

    Pseudomeningocele is an uncommon but well-known complication of lumbar spine operations. Although it is mostly asymptomatic and managed conservatively in most cases, it is claimed as a causative factor of failed back surgery syndrome and requires surgery in some cases. Usually, its diagnosis is confidently done with imaging modalities such as magnetic resonance imaging, computed tomography and myelography. In this report, we describe a case of pseudomeningocele that communicated with a facet joint. The diagnostic approach for this unusual lesion and its probable causes are discussed. (orig.)

  13. Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Marcus Vinicius Cavalcante

    1998-12-31

    In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

  14. Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Marcus Vinicius Cavalcante

    1999-12-31

    In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

  15. Dose optimization in adult patients exams in a computerized tomography service

    International Nuclear Information System (INIS)

    Pimentel, Juliana; Finatto, Jerusa D.; Silva, Ana Maria Marques da; Froner, Ana Paula P.

    2013-01-01

    This paper presents a study of dose optimization in computed tomography X-ray of skull, chest and abdomen of adult patients, performed in a diagnostic imaging service in a large hospital. Images of a simulated dose phantom were acquired and the kVp, mAs, pitch, thickness and CTDI vol were collected directly from the equipment. Using the PACS system, regions of interest were delineated, where the mean and standard deviation of CT numbers for each protocol were been calculated. The optimization took into account the maintenance of the CT number and noise from images acquired with clinical protocols. It was observed that the protocols used in the service, in general, exhibit a low dose, despite the great variability among the different professional shifts. In examinations of the chest, skull and abdomen, changes in the values of mAs and pitch were suggested, allowing dose reductions (60%, 17% and 19%, respectively), without compromising the image diagnostic quality. (author)

  16. Electrical Resistance Tomography imaging of concrete

    KAUST Repository

    Karhunen, Kimmo; Seppä nen, Aku; Lehikoinen, Anssi; Monteiro, Paulo J.M.; Kaipio, Jari P.

    2010-01-01

    We apply Electrical Resistance Tomography (ERT) for three dimensional imaging of concrete. In ERT, alternating currents are injected into the target using an array of electrodes attached to the target surface, and the resulting voltages are measured

  17. 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...

  18. Computerized tomography of the painting 'The first mass in Brazil' (Vitor Meireles)

    International Nuclear Information System (INIS)

    Oliveira, Davi F.; Calza, Cristiane; Rocha, Henrique S.; Lopes, Ricardo T.

    2007-01-01

    In this work it was performed the radiographic analysis of the painting 'The First Mass in Brazil' ('Primeira Missa no Brasil) executed by Vitor Meireles, in 1860. Radiographic techniques have been used in museums to the study of cultural heritage objects in order to reveal internal details that would otherwise be invisible. This work used Computerized Radiography with an Imaging Plate detector (IP). It consists of a thin layer of photostimulable phosphor crystals (BaFBr:Eu 2+ ) deposited on a flexible polyester support film. When the IP is exposed to an x-ray source, part of the energy is stored as a latent image in the phosphor. Analyzing the radiographic images it is possible to observe the canvas weave, including stretching marks generated when the fabric was fixed on the wooden support. Several regions with detachment and cracking of painting were also revealed. When occurred losses of fabric, the holes were filled with mortar before the retouching; these areas, with higher density than the original painting support, can be clearly observed at the radiographs. The knowledge of all changes and its location is very important to the restoration process, especially in the first stage when the old reinforcement of the fabric will be replaced, in order to avoid the remove of painting pieces together to the reinforcement. (author)

  19. Hyperplanar Morphological Clustering of a Hippocampus by Using Volumetric Computerized Tomography in Early Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Sarawut Suksuphew

    2017-11-01

    Full Text Available Background: On diagnosing Alzheimer’s disease (AD, most existing imaging-based schemes have relied on analyzing the hippocampus and its peripheral structures. Recent studies have confirmed that volumetric variations are one of the primary indicators in differentiating symptomatic AD from healthy aging. In this study, we focused on deriving discriminative shape-based parameters that could effectively identify early AD from volumetric computerized tomography (VCT delineation, which was previously almost intangible. Methods: Participants were 63 volunteers of Thai nationality, whose ages were between 40 and 90 years old. Thirty subjects (age 68.51 ± 5.5 were diagnosed with early AD, by using Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV criteria and the National Institute of Neurological and Communicative Disorders and the Stroke and the Alzheimer’s disease and Related Disorders Association (NINCDS-ADRDA criteria, while the remaining 33 were in the healthy control group (age 67.93 ± 5.5. The structural imaging study was conducted by using VCT. Three uninformed readers were asked to draw left and right hippocampal outlines on a coronal section. The resultant shapes were aligned and then analyzed with statistical shape analysis to obtain the first few dominant variational parameters, residing in hyperplanes. A supervised machine learning, i.e., support vector machine (SVM was then employed to elucidate the proposed scheme. Results: Provided trivial delineations, relatively as low as 5 to 7 implicit model parameters could be extracted and used as discriminants. Clinical verification showed that the model could differentiate early AD from aging, with high sensitivity, specificity, accuracy and F-measure of 0.970, 0.968, 0.983 and 0.983, respectively, with no apparent effect of left-right asymmetry. Thanks to a less laborious task required, yet high discriminating capability, the proposed scheme is expected to be applicable in a

  20. Dosimetry in computerized tomography and evaluation of doses in organs in thorax scanning

    International Nuclear Information System (INIS)

    Alonso, Thêssa Cristina

    2016-01-01

    Computed tomography has promoted improvement of the diagnostic process by producing anatomical cut images with high quality and contrast between soft tissues which have very similar absorption of the X-ray beams. The objective of this study is to evaluate the technological park of CT in Brazil correlated with the wide world, and carry out studies of experimental dosimetry to understand the dose distribution feature using phantoms and different methods of measurement of kerma index, as well as perform measures of local doses in sensitive organs. To study the scanner geographic distribution and supply of computed tomography tests in Brazil, a comparison has been made with results found with the specified reference by Brazilian law (Ordinance GM / MS No. 1101, 2002; Resolution RE nº1016, 2006). For dosimetry studies, It was used a standard chest phantom and the anthropomorphic phantom. For image quality evaluation, it was used the CATPHAN-600 phantom. Scans were performed in a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using a pencil ionization chamber, thermoluminescent dosimeters and radiochromic film strips. Sensitive organ shielding devices were evaluated in order to verify their efficiency in organ dose reduction and its influence in the quality of image. Considering Brazilian population, the scanner park showed a greater amount than the minimum parameter recommended by Brazilian law. Dose measurements using three different methods showed the correct procedure of metrological reliability of the measurement system. The findings and conclusions of this study may contribute to the improvement of local practices in Computed Tomography tests, inserted in context of radiological protection in order to define reference levels for optimized diagnosis, and image quality control. (author)

  1. The diagnostic value of cranial computerized tomography in exogenous psychoses and mental disorders associated with organic diseases

    International Nuclear Information System (INIS)

    Strobl, G.; Reisner, Th.; Zeiler, K.; Vienna Univ.

    1980-01-01

    205 patients hospitalized in a psychiatric department were subjected to cranial computerized tomography. The diagnosis on discharge according to the ICD key in each case was ''psychoses or mental disorders associated with physical conditions''. Pathological findings were obtained in 67.8% of the patients. In the case of space-occupying lesions the connection between psychiatric symptoms and syndromes and the underlying organic disease is obvious. Moreover, with inflammatory, vascular or traumatic diseases, a relationship to focal lesions found on the computer tomography appears likely if backed by appropriate neurological indications in the history or an clinical examinations. However, when alterations signifying diffuse brain atrophy are obtained on computer tomography any connections with psychiatric features should be very critically evaluated and, in individual cases, such connections had better not be looked for at all. Especially in cases of psychoses or mental disorders associated with physical conditions cranial computerized tomography is of high diagnostic value and the indications for its implementation in these cases should be judged very leniently. (author)

  2. Time to Computerized Tomography Scan, Age, and Mortality in Acute Stroke.

    Science.gov (United States)

    Myint, Phyo Kyaw; Kidd, Andrew C; Kwok, Chun Shing; Musgrave, Stanley D; Redmayne, Oliver; Metcalf, Anthony K; Ngeh, Joseph; Nicolson, Anne; Owusu-Agyei, Peter; Shekhar, Raj; Walsh, Kevin; Day, Diana J; Warburton, Elizabeth A; Bachmann, Max O; Potter, John F

    2016-12-01

    Time to computerized tomography (CT) is important to institute appropriate and timely hyperacute management in stroke. We aimed to evaluate mortality outcomes in relation to age and time to CT scan. We used routinely collected data in 8 National Health Service trusts in East of England between September 2008 and April 2011. Stroke cases were prospectively identified and confirmed. Odds ratios (ORs) for unadjusted and adjusted models for age categories (24 hours) and in-hospital and early (<7 days) mortality outcomes were calculated. Of the 7693 patients (mean age 76.1 years, 50% male) included, 1151 (16%) died as inpatients and 336 (4%) died within 7 days. Older patients and those admitted from care home had a significantly longer time from admission until CT (P < .001). Patients who had earlier CT scans were admitted to stroke units more frequently (P < .001) but had higher in-patient (P < .001) and 7-day mortality (P < .001). Whereas older age was associated with increased odds of mortality outcomes, longer time to CT was associated with significantly reduced mortality within 7 days (corresponding ORs for the above time periods were 1.00, .61 [95% confidence interval {CI}: .39-.95], .39 [.24-.64], and .16 [.08-.33]) and in-hospital mortality (ORs 1.00, .86 [.64-1.15], .57 [.42-.78] and .71 [.52-.98]). Older age was associated with a significantly longer time to CT. However, using CT scan time as a benchmarking tool in stroke may have inherent limitations and does not appear to be a suitable quality marker. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  3. Computerized tomography attenuation values can be used to differentiate hydronephrosis from pyonephrosis.

    Science.gov (United States)

    Yuruk, Emrah; Tuken, Murat; Sulejman, Suhejb; Colakerol, Aykut; Serefoglu, Ege Can; Sarica, Kemal; Muslumanoglu, Ahmet Yaser

    2017-03-01

    To determine the diagnostic value of computerized tomography (CT) in differentiating pyonephrosis from hydronephrosis on the basis of attenuation values (Hounsfield unit-HU). Data of the patients with grades 1-3 hydronephrosis on abdominopelvic CT, who underwent nephrostomy tube placement for decompression of the collecting system, were retrospectively analyzed. Patient demographics and CT findings were recorded along with the first access urine culture results. Three physicians calculated the surface areas and the attenuation values of the dilated collecting systems using the system software. Mean HU of pyonephrosis and hydronephrosis cases was compared. A total of 105 patients with the mean age of 47.7 ± 15.5 (range 20-80) were included. The interclass correlation coefficient of three physicians was 0.981 for HU measurement and 0.999 for calculation of collecting system surface area. Of the patients, 47 (44.8 %) had pyonephrosis. Mean surface areas of the collecting system were similar in patients with pyonephrosis and hydronephrosis (1481.13 ± 1562.94 vs. 1612.94 ± 2261.4 mm 2 , p = 0.735). Urine cultures were positive in all patients with pyonephrosis, whereas 12.7 % of hydronephrosis cases had bacterial in first access urine culture. The HU of the patients with pyonephrosis was significantly higher that that of patients with hydronephrosis (13.51 ± 13.29 vs. 4.67 ± 5.37, p = 0.0001). Having a HU of 9.21 or over diagnosed pyonephrosis accurately with 65.96 % sensitivity and 87.93 % specificity. Measuring attenuation values of the collecting system may be useful to differentiate pyonephrosis from hydronephrosis. Diagnosing pyonephrosis accurately may avoid septic complications.

  4. Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability

    International Nuclear Information System (INIS)

    Soustiel, Jean F.; Mor, Nadav; Zaaroor, Menashe; Goldsher, Dorith

    2006-01-01

    There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis. A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol. MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV. The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account. (orig.)

  5. Comparison of Volumes between Four-Dimensional Computed Tomography and Cone-Beam Computed Tomography Images using Dynamic Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Eun; Won, Hui Su; Hong, Joo Wan; Chang, Nam Jun; Jung, Woo Hyun; Choi, Byeong Don [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Sungnam (Korea, Republic of)

    2016-12-15

    The aim of this study was to compare the differences between the volumes acquired with four-dimensional computed tomography (4DCT)images with a reconstruction image-filtering algorithm and cone-beam computed tomography (CBCT) images with dynamic phantom. The 4DCT images were obtained from the computerized imaging reference systems (CIRS) phantom using a computed tomography (CT) simulator. We analyzed the volumes for maximum intensity projection (MIP), minimum intensity projection (MinIP) and average intensity projection (AVG) of the images obtained with the 4DCT scanner against those acquired from CBCT images with CT ranger tools. Difference in volume for node of 1, 2 and 3 cm between CBCT and 4DCT was 0.54⁓2.33, 5.16⁓8.06, 9.03⁓20.11 ml in MIP, respectively, 0.00⁓1.48, 0.00⁓8.47, 1.42⁓24.85 ml in MinIP, respectively and 0.00⁓1.17, 0.00⁓2.19, 0.04⁓3.35 ml in AVG, respectively. After a comparative analysis of the volumes for each nodal size, it was apparent that the CBCT images were similar to the AVG images acquired using 4DCT.

  6. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Alonso, Thessa C.; Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z.; Silva, Teogenes A. da

    2014-01-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  7. Classification of lymph nodes in computerized tomography scans using extracting tools

    International Nuclear Information System (INIS)

    Alves, Allan F.F.; Pina, Diana R. de; Altemani, Joao M.C.

    2016-01-01

    Lymph node changes in the neck region may be originated by both inflammatory and tumor causes. Diagnostic imaging method such as computed tomography are used to distinguish between these two main causes of lymph nodes alterations. In this work we used feature extracting tools I CT scans such as the average value of pixels, wavelet entropy, skewness and kurtosis to assist the radiologist in diagnosing lymph nodes alterations. The wavelet entropy proved to be the best image characteristic parameter to differentiate between the two groups of patients evaluated in this study. The study of cervical lymph nodes changes by features extraction methods may prove to be an excellent tool to assist in differentiating between infectious / inflammatory and tumor causes in CT scans. (author)

  8. Calculating the number of shock waves, expulsion time, and optimum stone parameters based on noncontrast computerized tomography characteristics.

    Science.gov (United States)

    Foda, Khaled; Abdeldaeim, Hussein; Youssif, Mohamed; Assem, Akram

    2013-11-01

    To define the parameters that accompanied a successful extracorporeal shock wave lithotripsy (ESWL), namely the number of shock waves (SWs), expulsion time (ET), mean stone density (MSD), and the skin-to-stone distance (SSD). A total of 368 patients diagnosed with renal calculi using noncontrast computerized tomography had their MSD, diameter, and SSD recorded. All patients were treated using a Siemens lithotripter. ESWL success meant a stone-free status or presence of residual fragments 934 HUs and SSD >99 mm. The required number of SWs and the expected ET can be anticipated. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. X-ray exposure dose for the gonadal gland by the examination of computerized tomography and its protection

    International Nuclear Information System (INIS)

    Moriuchi, Iwao; Kaiya, Hisanori; Hirata, Toshifumi; Asada, Shuichi

    1978-01-01

    Computerized tomography (CT) is very useful for neuroradiological examination, and so it may possibly be used for screening tests. But x-ray exposure dose by a examination of CT is considerable, especially for the male gonadal gland. This study showed that the dose from a complete CT examination of 10 - 15 scans for a male gonadal gland was about 1,800 times more than a single plain neuroradiography. But by only a 0.07 mm lead equivalent protecter, the exposure dose resulting from CT for a gonadal gland could be reduced to 0.0 mrad. (auth.)

  10. Significance of cranial computerized tomography for diagnosis and therapy of inflammatory diseases of the brain and meninges in children

    Energy Technology Data Exchange (ETDEWEB)

    Kotlarek, F; Hauke, P; Zeumer, H [Technische Hochschule Aachen (Germany, F.R.). Abt. Kinderheilkunde; Technische Hochschule Aachen (Germany, F.R.). Abt. Neurologie)

    1979-01-01

    The significance of cranial computerized tomography (CCT) for the diagnosis and therapy of inflammatory diseases of the central nervous system in children is discussed in connection with five characteristic case studies. CCT is shown to be superior to classical neuroradiological approaches, and to allow important diagnostic insights: 1. the early recognition of diffuse brain edema and the resulting possibility of an early begin of therapy - 2. the pathological expansions of the cerebral ventricles of various etiology before a pathological enlargement of the head can be detected, and the size of the ventricles after neurosurgical therapy can be measured - 3. the early recognition of space-occupying inflammatory complications.

  11. Epiploic appendicitis and omental infarction. Findings in the ultrasonography and computerized tomography; Apendicitis epiploica e infarto omental. Hallazgos en ecografia y tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Migule, A.; Ripolles, T.; Martinez, M. J.; Morote, V.; Ruiz, A. [Hospital Universitario Dr. Peset. Valencia (Spain)

    2001-07-01

    Describe the findings in the ultrasonography and computerized tomography (CT) of the omental infarction and epiploic appendicitis. The clinical and radiological findings of the patients diagnosed in our hospital with epiploic appendicitis or omental infarctions between August 1994 and March 2001 were assessed retrospectively. We found a high incidence (42 cases) of these two diseases: 30 patients with diagnosis of epiploic appendicitis and 12 with the diagnosis of omental infarction. Four patients were treated surgically, while the remaining 38 were conservatively, without posterior complications. The ultrasonography and CT images is characteristics. making it possible to make a diagnosis of epiploic appendicitis or omental infarction with certainty. It is not necessary to make a differential diagnosis between the two entities because their prognosis and treatment are similar. Their incidence is much more frequent than that previously published. (Author) 19 refs.

  12. Sequential computerized tomography changes and related final outcome in severe head injury patients

    International Nuclear Information System (INIS)

    Lobato, R.D.; Gomez, P.A.; Alday, R.

    1997-01-01

    The authors analyzed the serial computerized tomography (CT) findings in a large series of severely head injured patients in order to assess the variability in gross intracranial pathology through the acute posttraumatic period and determine the most common patterns of CT change. A second aim was to compare the prognostic significance of the different CT diagnostic categories used in the study (Traumatic Coma Data Bank CT pathological classification) when gleaned either from the initial (postadmission) or the control CT scans, and determine the extent to which having a second CT scan provides more prognostic information than only one scan. 92 patients (13.3 % of the total population) died soon after injury. Of the 587 who survived long enough to have at least one control CT scan 23.6 % developed new diffuse brain swelling, and 20.9 % new focal mass lesions most of which had to be evacuated. The relative risk for requiring a delayed operation as related to the diagnostic category established by using the initial CT scans was by decreasing order: diffuse injury IV (30.7 %), diffuse injury III (30.5 %), non evacuated mass (20 %), evacuated mass (20.2 %), diffuse injury II (12.1 %), and diffuse injury I (8.6 %). Overall, 51.2 % of the patients developed significant CT changes (for worse or better) occurring either spontaneously or following surgery, and their final outcomes were more closely related to the control than to the initial CT diagnoses. In fact, the final outcome was more accurately predicted by using the control CT scans (81.2 % of the cases) than by using the initial CT scans (71.5 % of the cases only). Since the majority of relevant CT changes developed within 48 hours after injury a pathological categorization made by using an early control CT scan seems to be most useful for prognostic purposes. Prognosis associated with the CT pathological categories used in the study was similar independently of the moment of the acute posttraumatic period at which

  13. 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.

  14. Ultrasonic computerized tomography (CT) for temperature measurements with limited projection data based on extrapolated filtered back projection (FBP) method

    International Nuclear Information System (INIS)

    Zhu Ning; Jiang Yong; Kato, Seizo

    2005-01-01

    This study uses ultrasound in combination with tomography to obtain three-dimensional temperature measurements using projection data obtained from limited projection angle. The main feature of the new computerized tomography (CT) reconstruction algorithm is to employ extrapolation scheme to make up for the incomplete projection data, it is based on the conventional filtered back projection (FBP) method while on top of that taking into account the correlation between the projection data and Fourier transform-based extrapolation. Computer simulation is conducted to verify the above algorithm. An experimental 3D temperature distribution measurement is also carried out to validate the proposed algorithm. The simulation and experimental results demonstrate that the extrapolated FBP CT algorithm is highly effective in dealing with projection data from limited projection angle

  15. Proposal of recommendations for quality control in computerized tomography, with emphasis in new technologies

    International Nuclear Information System (INIS)

    Rodrigues, Marlon da Silva Brandao; Neves, Camila Nascimento das

    2016-01-01

    The use of computed tomography (CT) has continuously grown over the years and expanding its applications in different medical procedures. As a result, there was an increase of frequency and in collective dose. One of the strategies to maximize the benefits of this important imaging modality is the implementation of optimization of protection programs. As part of this process, a quality control should be established to ensure the correct performance of the scanner. Quality control protocols can be very useful to carry out all tests in a standard methodology and well-established tolerance values. However, to keep up with the constant advances in technology, these protocols must be constantly reviewed and updated to allow its application in different existing models. The objective of this work is to develop a quality control protocol based on international recommendations and in national standards. (author)

  16. Image characterization metrics for muon tomography

    Science.gov (United States)

    Luo, Weidong; Lehovich, Andre; Anashkin, Edward; Bai, Chuanyong; Kindem, Joel; Sossong, Michael; Steiger, Matt

    2014-05-01

    Muon tomography uses naturally occurring cosmic rays to detect nuclear threats in containers. Currently there are no systematic image characterization metrics for muon tomography. We propose a set of image characterization methods to quantify the imaging performance of muon tomography. These methods include tests of spatial resolution, uniformity, contrast, signal to noise ratio (SNR) and vertical smearing. Simulated phantom data and analysis methods were developed to evaluate metric applicability. Spatial resolution was determined as the FWHM of the point spread functions in X, Y and Z axis for 2.5cm tungsten cubes. Uniformity was measured by drawing a volume of interest (VOI) within a large water phantom and defined as the standard deviation of voxel values divided by the mean voxel value. Contrast was defined as the peak signals of a set of tungsten cubes divided by the mean voxel value of the water background. SNR was defined as the peak signals of cubes divided by the standard deviation (noise) of the water background. Vertical smearing, i.e. vertical thickness blurring along the zenith axis for a set of 2 cm thick tungsten plates, was defined as the FWHM of vertical spread function for the plate. These image metrics provided a useful tool to quantify the basic imaging properties for muon tomography.

  17. The magnetic field gradients generation for magnetic resonance tomography; Generacja gradientow pola magnetyczbego dla tomografii MR

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, A.; Skorka, T.; Kwiecinski, S. [Institute of Nuclear Physics, Cracow (Poland)

    1994-12-31

    To obtain three-dimensional images in the computerized tomography a gradient of magnetic field should be generated. In this paper the analytical as well as computerized calculations of magnetic coils for such purposes are presented. 4 refs, 8 figs.

  18. Manual and computerized measurement of coronal vertebral inclination on MRI images: A pilot study

    International Nuclear Information System (INIS)

    Vrtovec, T.; Likar, B.; Pernuš, F.

    2013-01-01

    Aim: A pilot study that presents a systematic approach for evaluating the variability of manual and computerized measurements of coronal vertebral inclination (CVI) on images acquired by magnetic resonance imaging (MRI). Materials and methods: Three observers identified the vertebral body corners of 28 vertebrae on two occasions on two-dimensional (2D) coronal MRI cross-sections, which served to evaluate CVI using six manual measurements (superior and inferior tangents, left and right tangents, mid-endplate and mid-wall lines). Computerized measurements were performed by evaluating CVI from the symmetry of vertebral anatomical structures of the same 28 vertebrae in 2D coronal MRI cross-sections and in three-dimensional (3D) MRI images. Results: In terms of standard deviation (SD), the mid-endplate lines proved to be the manual measurements with the lowest intra- (1.0° SD) and interobserver (1.4° SD) variability. The computerized measurements in 3D yielded even lower intra- (0.8° SD) and interobserver (1.3° SD) variability. The strongest inter-method agreement (1.2° SD) was found among lines parallel to vertebral endplates (superior tangents, inferior tangents, mid-endplate lines). The computerized measurements in 3D were most in agreement with the mid-endplate lines (1.9° SD). The estimated intra- and interobserver variabilities of standard Cobb angle measurements were equal to 1.6° SD and 2.5° SD, respectively, for manual measurements, and to 1.1° SD and 1.8° SD, respectively, for computerized measurements. Conclusion: The mid-endplate lines proved to be the most reproducible and reliable manual CVI measurements. Computerized CVI measurements based on the evaluation of the symmetry of vertebral anatomical structures in 3D were more reproducible and reliable than manual measurements

  19. Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, Raj; Fowler, Allan; Hunt, Peter

    1995-01-15

    Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of {<=} 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position.

  20. Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

    International Nuclear Information System (INIS)

    Mallik, Raj; Fowler, Allan; Hunt, Peter

    1995-01-01

    Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of ≤ 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position

  1. Cellular imaging electron tomography and related techniques

    CERN Document Server

    2018-01-01

    This book highlights important techniques for cellular imaging and covers the basics and applications of electron tomography and related techniques. In addition, it considers practical aspects and broadens the technological focus by incorporating techniques that are only now becoming accessible (e.g. block face imaging).  The first part of the book describes the electron microscopy 3D technique available to scientists around the world, allowing them to characterize organelles, cells and tissues. The major emphasis is on new technologies like scanning transmission electron microscopy (STEM) tomography, though the book also reviews some of the more proven technologies like electron tomography. In turn, the second part is dedicated to the reconstruction of data sets, signal improvement and interpretation.

  2. Five and eight image tomography

    International Nuclear Information System (INIS)

    Bell, P.R.; Dillon, R.S.

    1977-01-01

    This method can be implemented with standard equipment and only requires images with the usual total count and time. The time for image reconstruction is negligible since 6 slices are reconstructed in 40 seconds. While the resolution in the slices is relatively poor, it is sufficient for the location of emitting structures shown in the standard views

  3. Development of a pediatric chest phantom for dosimetry in computerized tomography

    International Nuclear Information System (INIS)

    Aburjaile, W.N.; Mourão, A.P.; Oliveira, F.A.

    2017-01-01

    Computed Tomography (CT) has promoted a significant increase in the dose absorbed by patients due to the diagnosis. Therefore, it is indispensable to improve protocols, using smaller doses, without impairing the diagnostic quality of the image. The risks of stochastic effects are greater for children due to tissue radiosensitivity coupled with longer life expectancy. In the work, a cylindrical simulator was used, representing an adult thorax, made of polymethylmethacrylate, and a second simulator object of the same material was developed in oblong format including the axillary regions based on the dimensions of the pediatric patient's 8-year-old chest. A comparative study was performed between chest scans performed on two CT equipment in different radiodiagnostic services. The central slice of the two simulating objects was irradiated successively and, using a pencil-type ionization chamber, the absorbed dose was measured at five different points of each simulating object. From the measurements, weighted Dose and Volumetric Dose Index (CK, PMMA, vol) values were obtained for the 10 cm sweep of the central region of the object, in helical mode. The scans were performed using the chest acquisition protocols used by radiodiagnostic services, both for a supply voltage of the 120 kV X-ray tube. The study allowed to compare the variation of absorbed dose between patients with distinct chest volumes and the patient dose variation between two devices when used for the generation of images with the same diagnostic objective

  4. Optimization of recommendations for abdomen computerized tomography based on reconstruction filters, voltage and tube current

    International Nuclear Information System (INIS)

    Silveira, Vinicius da Costa

    2015-01-01

    The use of computed tomography has increased significantly over the past decades. In Brazil the use increased more than twofold from 2008 to 2014, in the meantime the abdomen procedures have tripled. The high frequency of this procedure combined by the increasing collective radiation dose in medical exposures, has resulted development tools to maximize the benefit in CT images. This work aimed to establish protocols optimized in abdominal CT through acquisitions parameters and reconstructions techniques based on filters kernels. A sample of patients undergoing abdominal CT in a diagnostic center of Rio de Janeiro was assessed. Had been collected patients information and acquisitions parameters. The phantoms CT image acquisitions were performed by using different voltage values by adjusting the tube current (mAs) to obtain the same value from CTDI vol patients with normal BMI. Afterwards, the CTDIvol values were reduced by 30%, 50% and 60%. All images were reconstructed with low-contrast filters (A) and standard filters (B). The CTDIvol values for patients with normal BMI were 7% higher than in patients with underweight BMI and 30%, 50% and 60% lower than the overweight, obese I and III patients, respectively. The evaluations of image quality showed that variation of the current (mA) and the reconstruction filters did not affect the Hounsfield values. When the contrast-to-noise ratio (CNR) was normalized to CTDIvol, the protocols acquired with 60% reduction of CTDIvol with 140 kV and 80 kV showed CNR 6% lower than the routine. Modifications of the acquisition parameters did not affect spatial resolution, but the post-processing with B filters reduced the spatial frequency by 16%. With reduced the dose of 30%, lesions in the spleen had the CNR higher than 10% routine protocols with 140 kV acquired and post-processed to filter A. The image post-processing with a filter A with a 80kV voltage provided CNR values equal to the routine for the liver lesions with a 30

  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. Clinical performance of dual-source computerized tomography (DSCT) in primary diagnostics of coronary heart diseases

    International Nuclear Information System (INIS)

    Brunner, H.; Froehner, S.; Wagner, M.; Schmitt, R.; Brunn, J.; Gietzen, F.H.; Kerber, S.

    2008-01-01

    Dual-source-CT-technology (DSCT) improves temporal resolution of cardiac computed tomography to 83 ms per heart-phase. In this study, the clinical performance of this new method is evaluated. Materials and Methods: In fifty patients (33 male, 17 female; age 50±13 years) with suspected coronary heart disease, CT angiography (slice thickness 0,75 mm, contrast-agent 60-80 ml iomeprol) was performed with a Somatom Definition scanner. Based on the coronary 15-segment-model of the AHA, scores for image quality and lumen reduction were established to enable the observer, to give recommendations for further therapy. Results: Out of 750 possible AHA-segments, 655 were depicted (87,3%). 591 segments (90,2%) were assessed without any limitation of quality, 49 (7,5%) segments showed moderate, and 15 (2,3%) segments severe limitation in image quality. 508 (77,6%) segments were without pathological findings, 92 (14,0%) segments had minimal atherosclerotic lesions, 42 (6,4%) segments suffered from stenoses with lumen reduction less than 70%, and 13 (2,0%) showed significant stenoses of more than 70%. In 31 patients (62%), coronary heart disease was ruled out by CT angiography without any need for further non-invasive or invasive diagnostics. 8 patients (16%) underwent stress-testing for ischemia. In 11 (22%) patients coronary angiography was recommended, and DSCT findings were confirmed in 10 cases. Only one LCx stenosis was overestimated in DSCT. Conclusion: Contrast-enhanced DSCT is a powerful tool in diagnosis of coronary heart disease. 98% of coronary segments could be assessed in diagnostic quality, and at least 90% of haemodynamically significant coronary stenoses were detected. (orig.)

  7. Determination of the initial energy in computerized tomography with proton beams; Determinacao da energia inicial em tomografia computadorizada com feixe de protons

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Rodrigo Luis da

    2007-07-01

    In earliest works devoted to proton computed tomography it was shown that the advantage of pCT image reconstruction appears when the energy is close to the Bragg peak region, since the proton passes the object. This effect provided by the Bragg peak makes the computerized tomography with protons possible. However, when decreasing the initial proton energy, with the increase of the irradiation dose, there are two effects that work simultaneously in opposite ways. First, the energy loss of a proton in an object becomes bigger at small initial energy. At the same time decreasing of the proton energy results in the increase of the energy straggling, requiring a larger number of protons. In this work the radiation dose dependence on the proton initial energy was studied using analytical formulas and computer simulations. The investigation determined that the radiation dose practically does not depend on the initial energy, except in the energy region very close to the minimum energy necessary to pass the object. (author)

  8. Small scale imaging using ultrasonic tomography

    International Nuclear Information System (INIS)

    Zakaria, Z.; Abdul Rahim, R.; Megat Ali, M.S.A.; Baharuddin, M.Y.; Jahidin, A.H.

    2009-01-01

    Ultrasound technology progressed through the 1960 from simple A-mode and B-mode scans to today M-mode and Doppler two dimensional (2-D) and even three dimensional (3-D) systems. Modern ultrasound imaging has its roots in sonar technology after it was first described by Lord John Rayleigh over 100 years ago on the interaction of acoustic waves with media. Tomography technique was developed as a diagnostic tool in the medical area since the early of 1970s. This research initially focused on how to retrieve a cross sectional images from living and non-living things. After a decade, the application of tomography systems span into the industrial area. However, the long exposure time of medical radiation-based method cannot tolerate the dynamic changes in industrial process two phase liquid/ gas flow system. An alternative system such as a process tomography systems, can give information on the nature of the flow regime characteristic. The overall aim of this paper is to investigate the use of a small scale ultrasonic tomography method based on ultrasonic transmission mode tomography for online monitoring of liquid/ gas flow in pipe/ vessel system through ultrasonic transceivers application. This non-invasive technique applied sixteen transceivers as the sensing elements to cover the pipe/ vessel cross section. The paper also details the transceivers selection criteria, hardware setup, the electronic measurement circuit and also the image reconstruction algorithm applied. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases. (author)

  9. Computerized Analysis of MR and Ultrasound Images of Breast Lesions

    National Research Council Canada - National Science Library

    Giger, Maryellen Lissak

    2000-01-01

    ...) images of breast lesions to aid radiologists in their workup of suspect lesions. We currently have retrospectively collected over 400 ultrasound cases of mass lesions, all that had gone on to either biopsy or cyst aspiration...

  10. Investigating the correlation between computerized tomography changes and quantitative consciousness disturbances in stroke patients

    International Nuclear Information System (INIS)

    Toneva, Yu.; Manchev, I.; Tsolova, M.

    1997-01-01

    One-hundred and nine patients undergo computerized tomographic (CT) and clinical investigations. The correlation between CT finding and quantitative consciousness disturbances has been studied. The somatic, neurologic and mental states are evaluated, and the changes in consciousness are classified according to a 4-degree rating system adopted in this country, namely: obnubilation, somnolence, sopor and coma. For the purpose a computerized tomograph CE 10000 is used. Cerebral infarctions in the right middle cerebral artery pool predominate. Here the disturbances are of a milder degree - obnubilation and somnolence. In stroke syndrome cases the states of sopor and coma are more frequent which may be explained with the rather severely manifested brain edema. In either form of cerebrovascular disease the quantitative disorders of consciousness are not dependent on the location of the accident in the dominant hemisphere. They are directly related to the CT documented size of pathological focus

  11. Diffuse lung neoplasms. Correlation between high resolution computerized tomography and anatomopathology; Neoplasias pulmonares difusas: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

    Energy Technology Data Exchange (ETDEWEB)

    Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Irion, Klaus L. [Complexo Hospitalar Santa Casa de Porto Alegre, RS (Brazil). Servico de Radiologia do Pavilhao Pereira Filho; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto, SP (Brazil)]. E-mail: edmarchiori@zipmail.com.br

    2002-08-01

    A short comparative evaluation study between high resolution computerized tomography and anatomopathologic findings is presented. The association of these two diagnostic techniques is discussed as a factor to enhance the accuracy of diffuse lung diseases, such as carcinomatous lymphangitis, Kaposi's Sarcoma, lymphomas, hematogenic metastases, bronchiole-alveolar carcinoma and leukemia. (MAC)

  12. Positron emission tomography tracers for imaging angiogenesis

    International Nuclear Information System (INIS)

    Haubner, Roland; Beer, Ambros J.; Wang, Hui; Chen, Xiaoyuan

    2010-01-01

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or α v β 3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging α v β 3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  13. A Micro-Scale Investigation on the Behaviors of Asphalt Mixtures under Freeze-Thaw Cycles Using Entropy Theory and a Computerized Tomography Scanning Technique

    Directory of Open Access Journals (Sweden)

    Huining Xu

    2018-01-01

    Full Text Available The thermodynamic behavior of asphalt mixtures is critical to the engineers since it directly relates to the damage in asphalt mixtures. However, most of the current research of the freeze-thaw damage of asphalt mixtures is focused on the bulk body from the macroscale and lacks a fundamental understanding of the thermodynamic behaviors of asphalt mixtures from the microscale perspective. In this paper, to identify the important thermodynamic behaviors of asphalt mixtures under freeze-thaw loading cycle, the information entropy theory, an X-ray computerized tomography (CT scanner and digital image processing technology are employed. The voids, the average size of the voids, the connected porosity, and the void number are extracted according to the scanned images. Based on the experiments and the CT scanned images, the information entropy evolution of the asphalt mixtures under different freeze-thaw cycles is calculated and the relationship between the change of information entropy and the pore structure characteristics is established. Then, the influences of different freezing and thawing conditions on the thermodynamic behaviors of asphalt mixtures are compared. The combination of information entropy theory and CT scanning technique proposed in this paper provides an innovative approach to investigate the thermodynamics behaviors of asphalt mixtures and a new way to analyze the freeze-thaw damage in asphalt mixtures.

  14. Pathologic assessment of computerized tomography accuracy for the evaluation of the laryngeal cartilagineous framework in laryngopharyngeal carcinomas

    International Nuclear Information System (INIS)

    Sulfaro, S.; Volpe, R.; Carbone, A.; Barzan, L.; Comoretto, R.

    1989-01-01

    Syxty-six whole-organ sectioned laryngopharyngectomy specimens removed for cancer during a seven-year period were uniformly examined to determine the accuracy of preoperative high resolution computerized tomography (CT) for detection of cartilaginous involvement. Results achived indicate that CT has a high overall specificity (88.2%) but a low sensitivity (47.1%); high false negative rate (26.5%) and a fairly low false-positive rate (5.9%) are observed. Massive cartilage destruction was easily assessed by CT, whereas both small macroscopic and microscopic neoplastic foci of cartilaginous invasion were missed on CT scans. Moreover, false-positive cases were mainly due to proximity of the tumor to the cartilage. Clinical implications of these results are discussed

  15. Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

    Energy Technology Data Exchange (ETDEWEB)

    Sondheimer, H.M. (Upstate Medical Center, Syracuse, NY); Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

    1982-05-01

    To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease.

  16. Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols.

    Science.gov (United States)

    Qu, Xing-min; Li, Gang; Ludlow, John B; Zhang, Zu-yan; Ma, Xu-chen

    2010-12-01

    The aim of this study was to compare effective doses resulting from different scan protocols for cone-beam computerized tomography (CBCT) using International Commission on Radiological Protection (ICRP) 1990 and 2007 calculations of dose. Average tissue-absorbed dose, equivalent dose, and effective dose for a ProMax 3D CBCT with different dental protocols were calculated using thermoluminescent dosimeter chips in a human equivalent phantom. Effective doses were derived using ICRP 1990 and the superseding 2007 recommendations. Effective doses (ICRP 2007) for default patient sizes from small to large ranged from 102 to 298 μSv. The coefficient of determination (R(2)) between tube current and effective dose (ICRP 2007) was 0.90. When scanning with lower resolution settings, the effective doses were reduced significantly (P radiation dose levels. Reduction in radiation dose can be achieved when using lower settings of exposure parameters. Copyright © 2010 Mosby, Inc. All rights reserved.

  17. Interstitial lung illness: Discoveries in x-ray of the thorax vs computerized tomography of high resolution

    International Nuclear Information System (INIS)

    Patino O, Maria Olga; Gomez Ramirez, Rafael

    1993-01-01

    This study wants to prove the advantages of the computerized axial tomography (TAC) of high resolution on the conventional radiography and the follow-up of the patients with interstitial pulmonary disease (IPD). 29 patients were studied with conventional RX and TAC with 17. $ % of high resolution which had normal radiography with clear abnormalities in the TAC of high resolution, the type of interstitial pulmonary disease (IPD). In the 68,9% of the cases it showed abnormality as well in TAC as in conventional RX. In the fact, that the TAC does not allow a specific etiologic diagnosis of the IPD type, as it is done in the biopsy. It allows identifying abnormality in those patients apparently normal by the radiography of the thorax and when it already exists the histopathologic diagnosis it allows the follow-up in a no invasive way

  18. Positron emission tomography imaging--technical considerations

    International Nuclear Information System (INIS)

    Muehllehner, G.; Karp, J.S.

    1986-01-01

    Positron imaging instrumentation has improved rapidly in the last few years. Scanners currently under development are beginning to approach fundamental limits set by positron range and noncolinearity effects. This report reviews the latest developments in positron emission tomography (PET) instrumentation, emphasizing the development of coding schemes that reduce the complexity and cost of high-resolution scanners. The relative benefits of using time-of-flight (TOF) information is discussed as well. 68 references

  19. Analysis of absorbed dose in cervical spine scanning by computerized tomography using simulator objects

    International Nuclear Information System (INIS)

    Lyra, Maria Henriqueta Freire

    2015-01-01

    The Computed tomography (CT) has become an important diagnostic tool after the continued development of Multidetector CT (MDCT), which allows faster acquisition of images with better quality than the previous technology. However, there is an increased radiation exposure, especially in examinations that require more than one acquisition, as dynamic exams and enhancement studies in order to discriminate low contrast soft tissue injury from normal tissue. Cervical spine MDCT examinations are used for diagnosis of soft tissue and vascular changes, fractures, dysplasia and other diseases with instability, which guide the patient treatment and rehabilitation. This study aims at checking the absorbed dose range in the thyroid and other organs during MDCT scan of cervical spine, with and without bismuth thyroid shield. In this experiment a cervical spine MDCT scan was performed on anthropomorphic phantoms, from the occipital to the first thoracic vertebra, using a 64 and a 16 – channel CT scanners. Thermoluminescent dosimeters were used to obtain the absorbed dose in thyroid, lenses, magnum foramen and breasts of the phantom. The results show that the thyroid received the highest dose, 60.0 mGy, in the female phantom, according to the incidence of the primary X-ray beam. The absorbed doses in these tests showed significant differences in the evaluated organs, p value < 0.005, except for the magnum foramen and breasts. With the bismuth thyroid shield applied on the female phantom, the doses in the thyroid and in the lenses were reduced by 27% and 52%, respectively. On the other hand, a reduction of 23.3% in the thyroid and increasing of 49.0% in the lens were measured on the male phantom. (author)

  20. Optimization of special heart disease diagnosis by combined computerized tomography, echocardiography and intracardiac scintiscanning

    International Nuclear Information System (INIS)

    Freitag, J.; Schmidt, H.; Otto, H.J.; Punrich, R.; Gunkel, H.; Mann, D.; Freitag, G.; Waigand, J.; Eger, H.; Zentralklinik fuer Herz- u. Lungenkrankheiten, Bad Berka; Akademie der Wissenschaften der DDR, Berlin-Buch. Zentralinstitut fuer Herz-Kreislaufforschung)

    1986-01-01

    Cardiac computer tomography, echocardiography and radionuclide heart diagnosis are growing more and more important in cardiologic diagnostics. The value of the procedures was tested in 74 patients by combined application. Concordant morphologic findings could be obtained with echocardiography and cardiac computer tomography in the cases of chronic ischemic heart disease, cardiomyopathy and valvular heart diseases. Localized kinetic disturbances could be registered echocardiographically and by scintiscanning. The passableness of an aortocoronary bypass can be controlled first of all non-invasively by cardiac computer tomography. (author)

  1. Use of morphologic filters in the computerized detection of lung nodules in digital chest images

    International Nuclear Information System (INIS)

    Yoshimura, H.; Giger, M.L.; Doi, K.; Ahn, N.; MacMahon, H.

    1989-01-01

    The authors have previously described a computerized scheme for the detection of lung nodules based on a difference-image approach, which had a detection accuracy of 70% with 7--8 false positives per image. Currently, they are investigating morphologic filters for the further enhancement/suppression of nodule-signals and the removal of false-positives. Gray-level morphologic filtering is performed on clinical chest radiographs digitized with an optical drum scanner. Various shapes and sequences of erosion and dilation filters (i.e., determination of the minimum and maximum gray levels, respectively) were examined for signal enhancement and suppression for sue in the difference- image approach

  2. 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...... applications. This thesis takes a systematic approach toward establishing quantitative understanding of conditions for sparse reconstruction to work well in CT. A general framework for analyzing sparse reconstruction methods in CT is introduced and two sets of computational tools are proposed: 1...... contributions to a general set of computational characterization tools. Thus, the thesis contributions help advance sparse reconstruction methods toward routine use in...

  3. Computerized image analysis: estimation of breast density on mammograms

    Science.gov (United States)

    Zhou, Chuan; Chan, Heang-Ping; Petrick, Nicholas; Sahiner, Berkman; Helvie, Mark A.; Roubidoux, Marilyn A.; Hadjiiski, Lubomir M.; Goodsitt, Mitchell M.

    2000-06-01

    An automated image analysis tool is being developed for estimation of mammographic breast density, which may be useful for risk estimation or for monitoring breast density change in a prevention or intervention program. A mammogram is digitized using a laser scanner and the resolution is reduced to a pixel size of 0.8 mm X 0.8 mm. Breast density analysis is performed in three stages. First, the breast region is segmented from the surrounding background by an automated breast boundary-tracking algorithm. Second, an adaptive dynamic range compression technique is applied to the breast image to reduce the range of the gray level distribution in the low frequency background and to enhance the differences in the characteristic features of the gray level histogram for breasts of different densities. Third, rule-based classification is used to classify the breast images into several classes according to the characteristic features of their gray level histogram. For each image, a gray level threshold is automatically determined to segment the dense tissue from the breast region. The area of segmented dense tissue as a percentage of the breast area is then estimated. In this preliminary study, we analyzed the interobserver variation of breast density estimation by two experienced radiologists using BI-RADS lexicon. The radiologists' visually estimated percent breast densities were compared with the computer's calculation. The results demonstrate the feasibility of estimating mammographic breast density using computer vision techniques and its potential to improve the accuracy and reproducibility in comparison with the subjective visual assessment by radiologists.

  4. Determination of the dose index in computerized tomography using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Azorin, J.C.; Calderon, A.; Azorin, J.

    2004-01-01

    In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

  5. Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

    International Nuclear Information System (INIS)

    King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R.

    2010-01-01

    Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed

  6. Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R. [Department of Radiology, Committee on Medical Physics, University of Chicago, 5841 South Maryland Avenue, MC 2026, Chicago, Illinois 60637 (United States); Department of Diagnostic Radiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239 (United States); Department of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 5084, Chicago, Illinois 60637 (United States)

    2010-11-15

    Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed

  7. 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...

  8. Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter

    2010-01-01

    , and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...

  9. Computerized mini-tomography scanner for X-ray and gamma-ray for multipurpose applications

    International Nuclear Information System (INIS)

    Cruvinel, P.E.

    1987-01-01

    The main results of this thesis is the development, implementation and use of an X-ray and γ-ray computerized minitomography scanner with possible applications in multidisciplinary fields particularly in soil physics. The hardware is basically a mechanical table with two step motors, one for rotation and another for translation motions, radioactive source, collimators, radiation detector with NaI(Tl) crystal, electronic pulse handling system and microcomputer with two floppy disk-units (5 1/4''), video with high resolution and graphic printer.(author)

  10. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    Richey, J.B.; Wake, R.H.; Walters, R.G.; Hunt, W.F.; Cool, S.L.

    1980-01-01

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  11. Elementary representative sizes of soil attributes via attenuation of gamma rays and computerized tomography

    International Nuclear Information System (INIS)

    Borges, Jaqueline Aparecida Ribaski

    2015-01-01

    In this study, the Computed Tomography (CT) and gamma-ray attenuation (GRA) techniques were used in the investigation of representative sample sizes for attributes related to soil structure. First of all, the representative elementary length (REL) for experimental measurements of soil mass attenuation coefficient (μes), of samples from a sandy and a clayey soil, was analyzed. The study was conducted with two radioactive sources ( 241 Am and 137 Cs), three collimators (2 - 4 mm diameters), and 14 thickness (x) samples (2-5 cm). From these analyzes, it was possible to identify an ideal thickness range for each of the studied sources (2-4 cm and 12-15 cm for the sources of 241 Am and 137 Cs, respectively). The application of such results in representative elementary area evaluations, in clayey soil clods via CT, indicated that experimental soil mass attenuation coefficient average values obtained for x>4 cm and source 241 Am might induce the use of samples which are not large enough for soil bulk density evaluations. Subsequently, μCT images with a total volume of 39×39×33 mm 3 and spatial resolution of 60 μm were used for macroporous system morphological characterization of a Rhodic Ferralsol with clayey texture, under no-till (NT) and conventional till (CT) systems. Attributes as macroporosity (MAP), number of macropores (NMAP), tortuosity (τ) and connectivity (C) of the pores were assessed. The C degree was estimated based on the Euler-Poincare characteristic (EPC). Once 3D images enable the study of these attributes in different sample volumes, the proposed study is ideal for the analysis of representative elementary volume (REV). Usually, the selection of subvolumes for REV analysis occurs concentrically to a small volume or in adjacent positions. Here, we introduced a new method for selecting the positions of subvolumes, which are randomly chosen within the total image volume (random selection). It was observed that higher fluctuations in amplitude of each

  12. Global Seismic Imaging Based on Adjoint Tomography

    Science.gov (United States)

    Bozdag, E.; Lefebvre, M.; Lei, W.; Peter, D. B.; Smith, J. A.; Zhu, H.; Komatitsch, D.; Tromp, J.

    2013-12-01

    Our aim is to perform adjoint tomography at the scale of globe to image the entire planet. We have started elastic inversions with a global data set of 253 CMT earthquakes with moment magnitudes in the range 5.8 ≤ Mw ≤ 7 and used GSN stations as well as some local networks such as USArray, European stations, etc. Using an iterative pre-conditioned conjugate gradient scheme, we initially set the aim to obtain a global crustal and mantle model with confined transverse isotropy in the upper mantle. Global adjoint tomography has so far remained a challenge mainly due to computational limitations. Recent improvements in our 3D solvers (e.g., a GPU version) and access to high-performance computational centers (e.g., ORNL's Cray XK7 "Titan" system) now enable us to perform iterations with higher-resolution (T > 9 s) and longer-duration (200 min) simulations to accommodate high-frequency body waves and major-arc surface waves, respectively, which help improve data coverage. The remaining challenge is the heavy I/O traffic caused by the numerous files generated during the forward/adjoint simulations and the pre- and post-processing stages of our workflow. We improve the global adjoint tomography workflow by adopting the ADIOS file format for our seismic data as well as models, kernels, etc., to improve efficiency on high-performance clusters. Our ultimate aim is to use data from all available networks and earthquakes within the magnitude range of our interest (5.5 ≤ Mw ≤ 7) which requires a solid framework to manage big data in our global adjoint tomography workflow. We discuss the current status and future of global adjoint tomography based on our initial results as well as practical issues such as handling big data in inversions and on high-performance computing systems.

  13. Laboratory of computerized tomography and X-ray of Centro Federal de Educacao Tecnologica (CEFET) from Parana State, Brazil

    International Nuclear Information System (INIS)

    Schelin, Hugo R.; Paschuk, Sergei A.; Jakubiak, Rosangela J.; David, Denise E.H.; Gomes, Cintia L.; Soboll, Daniel S.; Ruehle, Gustavo; Carvalho, Arnolfo

    1996-01-01

    The development of X-ray laboratory at CEFET-PR (Brazil) is considered. The advancement and hospital practice application of an Image Quality Program for X-ray and tomography scanning is studied. A project regarding to the modernization of installed X-ray equipment, particularly X-ray detector, software and hardware is reported

  14. Complaints of the lumbar spine: The value of myelography and computerized tomography

    International Nuclear Information System (INIS)

    Rittmeyer, K.; Dralle, A.

    1988-01-01

    In the radiological examination of the lumbar spine and vertebral canal there are currently two methods of choice, computer tomography and myelography. Comparing the advantages of one method over another reveals that computer tomography is particularly useful in especially diagnosing a lateral process of the intervertebral disk, whereas myelography is especially applicable in the case of an intervertebrals disk prolapse within the narrow confines of the spinal canal proper. Myelography also has the additional advantage of visualizing a number of segments at once, although repeated use increases the risk of arachnitis despite the high tolerance of current contrast medium. However, myelography should be performed, if there is clinical evidence of nerve root compression even though the computer tomography was negative. The reverse is also true. Myelography is also useful initially, due to the lower radiation dosis, if the clinical symptoms don't allow a specific localisation of the process. (orig.) [de

  15. Computerized digital image processing on radiographs of canine filariosis

    International Nuclear Information System (INIS)

    Miyatake, K.; Okamoto, Y.; Minami, S.

    1999-01-01

    For objective evaluation in the lung arterial lesions, density histogram revealed by survey thoracic radiographies of fifteen canine filariosis and five normal canine were digitally analyzed, and preparation of pulmonary artery angiogram with inflated-fixed lung, the changes in the histogram and the pulmonary arterial lesion by a soft X-ray examination were compared. In the lung areas affected by filariosis, the density histogram increased the white level and decreased the black level in each part compared to a normal lung. In comparison with the normal parameters, those of the filariosis it were significantly increased in minimum grey level values (Min), maximum grey level values (Max), and the maximum frequency grey level values (Mode) and, it was significantly decreased in maximum frequency values (MaF). The pulmonary arterial lesion of the filariosis showed obvious morphological changes such as in distinction, pruning, angiectasis, and meandering. In the grade of pulmonary arterial lesion, the parameter Min, Max, Mode and MaF were changed significantly. From these results, it was clear that the methods for the lung arterial lesions analysis of X-ray images were confirmed to be highly beneficial in the lung arterial lesions for objective diagnosis

  16. System Matrix Analysis for Computed Tomography Imaging

    Science.gov (United States)

    Flores, Liubov; Vidal, Vicent; Verdú, Gumersindo

    2015-01-01

    In practical applications of computed tomography imaging (CT), it is often the case that the set of projection data is incomplete owing to the physical conditions of the data acquisition process. On the other hand, the high radiation dose imposed on patients is also undesired. These issues demand that high quality CT images can be reconstructed from limited projection data. For this reason, iterative methods of image reconstruction have become a topic of increased research interest. Several algorithms have been proposed for few-view CT. We consider that the accurate solution of the reconstruction problem also depends on the system matrix that simulates the scanning process. In this work, we analyze the application of the Siddon method to generate elements of the matrix and we present results based on real projection data. PMID:26575482

  17. Influence of ASIR (Adaptative Statistical Iterative Reconstruction) variation in the image noise of computerized tomography for high voltage; Influência da variação do ASIR (Adaptative Statistical Iterative Reconstruction) no ruído da imagem de tomografia computadorizada para altas tensões

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, L.M.M.; Pereira, W.B.R.; Vieira, J.G.; Lamounier, C.S.; Gonçalves, D.A.; Carvalho, G.N.P.; Santana, P.C., E-mail: lucasmoacir2010@hotmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Oliveira, P.M.C.; Reis, L.P., E-mail: paulomarcio2000@gmail.com [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Computed tomography had great advances in the equipment used in the diagnostic practice, directly influencing the levels of radiation for the patient. It is essential to optimize techniques that must be employed to comply with the ALARA (As Low As Reasonably Achievable) principle of radioprotection. The relationship of ASIR (Adaptive Statistical Iterative Reconstruction) with image noise was studied. Central images of a homogeneous water simulator were obtained in a 20 mm scan using a 64-channel Lightspeed VCT tomograph of General Electric in helical acquisitions with a rotation time of 0.5 seconds, Pitch 0.984: 1, and thickness of cut 0.625 mm. All these constant parameters varying the voltage in two distinct values: 120 and 140 kV with use of the automatic current by the CAE (Automatic Exposure Control), ranging from 50 to 675 mA (120 kV) and from 50 to 610 mA (140kV), minimum and maximum values, respectively allowed for each voltage. Image noise was determined through ImageJ free software. The analysis of the obtained data compared the percentage variation of the noise in the image based on the ASIR value of 10%, concluding that there is a variation of approximately 50% when compared to the values of ASIR (100%) in both tensions. Dose evaluation is required in future studies to better utilize the relationship between dose and image quality.

  18. Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

    Science.gov (United States)

    Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

    2009-04-01

    We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x

  19. Diffuse Optical Tomography for Brain Imaging: Theory

    Science.gov (United States)

    Yuan, Zhen; Jiang, Huabei

    Diffuse optical tomography (DOT) is a noninvasive, nonionizing, and inexpensive imaging technique that uses near-infrared light to probe tissue optical properties. Regional variations in oxy- and deoxy-hemoglobin concentrations as well as blood flow and oxygen consumption can be imaged by monitoring spatiotemporal variations in the absorption spectra. For brain imaging, this provides DOT unique abilities to directly measure the hemodynamic, metabolic, and neuronal responses to cells (neurons), and tissue and organ activations with high temporal resolution and good tissue penetration. DOT can be used as a stand-alone modality or can be integrated with other imaging modalities such as fMRI/MRI, PET/CT, and EEG/MEG in studying neurophysiology and pathology. This book chapter serves as an introduction to the basic theory and principles of DOT for neuroimaging. It covers the major aspects of advances in neural optical imaging including mathematics, physics, chemistry, reconstruction algorithm, instrumentation, image-guided spectroscopy, neurovascular and neurometabolic coupling, and clinical applications.

  20. Assessment of liver volume with spiral computerized tomography scanning: predicting liver volume by age and height

    OpenAIRE

    Madhu Sharma; Abhishek Singh; Shewtank Goel; Setu Satani; Kavita Mudgil

    2016-01-01

    Background: Estimation of liver size has critical clinical implication. Precise knowledge of liver dimensions and volume is prerequisite for clinical assessment of liver disorders. Liver span as measured by palpation and USG is prone to inter-observer variability and poor repeatability. The aim was to assess the normal liver volume of healthy adults using spiral computed tomography scans and to observe its relationship with various body indices. Methods: In this prospective study, all the...

  1. Radiation condition in computerized tomography (CT): determination and calibration of dosemeters

    International Nuclear Information System (INIS)

    Adrade, L.C.; Peixoto, J.G.P.

    2016-01-01

    RQT is the standard for radiation conditions in computed tomography . It simulates a beam unrelieved of a CT scanner . The camera pencil ionization dosimeter is used in CT. The LNMRI become known characterization of RQT radiation conditions and the secondary standard calibration for type pencil ionisation chambers in its lab. The obtained beam has the characteristics required by IEC 61267. The results of the calibration presented combined uncertainty expanded to 95.45% from 2.22% . (author)

  2. Electrical Resistance Tomography imaging of concrete

    International Nuclear Information System (INIS)

    Karhunen, Kimmo; Seppaenen, Aku; Lehikoinen, Anssi; Monteiro, Paulo J.M.; Kaipio, Jari P.

    2010-01-01

    We apply Electrical Resistance Tomography (ERT) for three dimensional imaging of concrete. In ERT, alternating currents are injected into the target using an array of electrodes attached to the target surface, and the resulting voltages are measured using the same electrodes. These boundary measurements are used for reconstructing the internal (3D) conductivity distribution of the target. In reinforced concrete, the metallic phases (reinforcing bars and fibers), cracks and air voids, moisture gradients, and the chloride distribution in the matrix carry contrast with respect to conductivity. While electrical measurements have been widely used to characterize the properties of concrete, only preliminary results of applying ERT to concrete imaging have been published so far. The aim of this paper is to carry out a feasibility evaluation with specifically cast samples. The results indicate that ERT may be a feasible modality for non-destructive evaluation of concrete.

  3. Electrical Resistance Tomography imaging of concrete

    KAUST Repository

    Karhunen, Kimmo

    2010-01-01

    We apply Electrical Resistance Tomography (ERT) for three dimensional imaging of concrete. In ERT, alternating currents are injected into the target using an array of electrodes attached to the target surface, and the resulting voltages are measured using the same electrodes. These boundary measurements are used for reconstructing the internal (3D) conductivity distribution of the target. In reinforced concrete, the metallic phases (reinforcing bars and fibers), cracks and air voids, moisture gradients, and the chloride distribution in the matrix carry contrast with respect to conductivity. While electrical measurements have been widely used to characterize the properties of concrete, only preliminary results of applying ERT to concrete imaging have been published so far. The aim of this paper is to carry out a feasibility evaluation with specifically cast samples. The results indicate that ERT may be a feasible modality for non-destructive evaluation of concrete. © 2009 Elsevier Ltd. All rights reserved.

  4. 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, ...

  5. Utilization of special computerized tomography and nuclear medicine techniques for quality control and for the optimization of combined precision chemotherapy and precision radiation therapy

    International Nuclear Information System (INIS)

    Wiley, A.L. Jr.; Wirtanen, G.W.; Chien, I.-C.

    1984-01-01

    A combination of precision (selective, intra-arterial) chemotherapy and precision radiotherapy can be used for advanced pancreatic, biliary tract, and sarcomatous malignancies. There were some remarkable responses, but also a few poor responses and even some morbidity. Accordingly, methods are developed of pre-selecting those patients whose tumors are likely to respond to such therapy, as well as methods for improving the therapeutic ratio by the rational optimization of combined therapy. Specifically, clinical tumor blood flow characteristics (monitored with nuclear medicine techniques) may provide useful criteria for such selection. The authors also evaluate qualitatively the drug distribution or exposure space with specialized color-coded computerized tomography images, which demonstrate spatially dependent enhancement of intra-arterial contrast in tumor and in adjacent normal tissues. Such clinical data can improve the quality control aspects of intra-arterial chemotherapy administration, as well as the possibility of achievement of a significant therapeutic ratio by the integration of precision chemotherapy and precision radiation therapy. (Auth.)

  6. A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: an in vitro study.

    Science.gov (United States)

    Gaurav, Vivek; Srivastava, Nikhil; Rana, Vivek; Adlakha, Vivek Kumar

    2013-01-01

    Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

  7. Experimental study of mechanisms of sand production using X-ray computerized tomography; Estudo experimental dos mecanismos da producao de areia empregando tomografia computadorizada de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Janaina B.; Vargas Junior, Euripedes [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil; Barroso, Emilio V. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Geologia; Campos, Elisabete; Goncalves, Clemente; Tavares, Andre [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    During productive phase of the well, many times there is simultaneous production of the solid particles detached from matrix of the reservoir rock. This phenomenon receives the name of the sand production. In this case stress and flow conditions around of the well are fundamental factors for deflagration of the process. Stress concentration in the wall of the well lead to the loss of cohesion between grains arising, consequently, a granular material region susceptible for dragging by seepage forces derived from fluid flow. The objective of this work was to perform sand production tests in Rio Bonito and synthetic sandstone samples using real-time X-Ray Computerized Tomography. The tests investigated the initial and the evolution of failure at the cavity wall of samples. These are initial stages of the sand production process. The analysis of the CT-scans obtained during tests allowed the visualization of breakouts and collapses of the wells. From studies more details were possible estimate the sand production and produce 3-D images of the propagation of the failure. (author)

  8. Functional cardiac imaging: positron emission tomography

    International Nuclear Information System (INIS)

    Mullani, N.A.; Gould, K.L.

    1984-01-01

    Dynamic cardiovascular imaging plays a vital role in the diagnosis and treatment of cardiac disease by providing information about the function of the heart. During the past 30 years, cardiovascular imaging has evolved from the simple chest x-ray and fluoroscopy to such sophisticated techniques as invasive cardiac angiography and cinearteriography and, more recently, to noninvasive cardiac CT scanning, nuclear magnetic resonance, and positron emission tomography, which reflect more complex physiologic functions. As research tools, CT, NMR, and PET provide quantitative information on global as well as regional ventricular function, coronary artery stenosis, myocardial perfusion, glucose and fatty acid metabolism, or oxygen utilization, with little discomfort or risk to the patient. As imaging modalities become more sophisticated and more oriented toward clinical application, the prospect of routinely obtaining such functional information about the heart is becoming realistic. However, these advances are double-edged in that the interpretation of functional data is more complex than that of the anatomic imaging familiar to most physicians. They will require an enhanced understanding of the physiologic and biochemical processes, as well as of the instrumentation and techniques for analyzing the data. Of the new imaging modalities that provide functional information about the heart, PET is the most useful because it quantitates the regional distribution of radionuclides in vivo. Clinical applications, interpretation of data, and the impact of PET on our understanding of cardiac pathophysiology are discussed. 5 figures

  9. Tomografía axial computarizada en pacientes con enfermedades cerebrovasculares hemorrágicas Computerized axial tomography in patients with hemorrhagic cerebrovascular diseases

    Directory of Open Access Journals (Sweden)

    Solángel Bolaños Vaillant

    2009-10-01

    Full Text Available Se efectuó un estudio descriptivo y transversal de 196 pacientes con enfermedad cerebrovascular hemorrágica, que abarcó desde enero del 2004 hasta igual mes del 2005 en el Hospital Provincial Docente “Saturnino Lora” de Santiago de Cuba, a los cuales se indicó una tomografía axial computarizada. Al relacionar las imágenes tomográficas con los síntomas y signos presentados por los enfermos, se halló lenguaje tropeloso en todos ellos; predominio de hematomas intraparenquimatosos, generalmente en ganglios basales y región temporal, así como primacía de la hipertensión arterial entre los antecedentes patológicos más importantes. Se concluyó que la tomografía axial computarizada es un medio para diagnóstico certero en las urgencias médicas por esa grave afección.A descriptive and cross sectional study of 196 patients with cerebrovascular hemorrhagic disease was carried out from January, 2004 to the same month of 2005 in "Saturnino Lora" Teaching Provincial Hospital from Santiago de Cuba, to whom a computerized axial tomography was indicated. When relating the tomographic images with the symptoms and signs which they presented, trouble speaking was detected in all of them; prevalence of intraparenchymatous hematomas, generally in basal ganglia and temporal region, as well as prevalence of hypertension among the most important pathological history. It was concluded that computarized axial tomography is a mean for precise diagnosis in medical emergencies due to that serious disorder.

  10. Prognosis of the computerized tomography in the severe head injury. Valor pronostico de la tomografia axial computada (TC) en los traumatismos craneoencefalicos severos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Nieto, J.J.; Lorenzo Dominguez, M.T.; Martin Sanchez, M.J.; Sanchez Gonzalez, E.

    1991-01-01

    A prospective study is made with sixty five people affected of severe head injury, that is to say, with eight or less points in the Glasgow Coma Scale (GCS), when they get to the hospital. They are studied by computerized tomography at admission, and three and seven days after arrival. In this way, we appraise the type of the lesion, its intensity and the possible prognosis, considering in the last case three features: a) ventricular collapse; b) the mean line structure s shift; and c) effects on perimesencephalic cistern. The findings were parametized and we were able to introduce into the computer program relationships between these findings and the end results. These last ones were appraised through the Glasgow Outcome Scale (GOS). We could show that certain findings in computerized tomography scans have an unavoidable prognosis while as others have a more favorable prognosis. (Author)

  11. Method of evaluation of diagnostics reference levels in computerized tomography; Metodo de avaliacao de niveis de referencia de radiodiagnostico em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  12. Absorbed dose to the patient by computerized whole body X-ray tomography

    International Nuclear Information System (INIS)

    Krauss, O.; Schuhmacher, H.

    1977-01-01

    The absorbed dose to the patient was measured for several medical investigations by computerized whole body scanning. An Alderson-phantom mounted with LiF-TLD was irradiated with a Delta-Scan (Ohio-Nuclear, 120 kV, 30 mA). The integral dose to the brain during a full examination (6 scans, filtration 3 mm Al) was measured to 5x10 -2 J. The maximum absorbed dose at the entrance was found to be 3.2 rd and at the exit 0.6 rd. The dose to the eyes is 0.7 rd and to the thyroid gland 0.03 rd. The integral dose to the trunk (5 scans in the region of liver and kidneys, filtration 6 mm Al) was measured to 5x10 -2 J. The maximum absorbed dose at the entrance was found to be 2.4 rd and at the exit 0.25 rd. The dose to the gonads is less than 2 and 4 mrd if the distance between the last scan and the gonads is more than 15 cm

  13. Evaluation of supra- and infratentorial brain atrophy by computerized tomography in spinocerebellar degeneration

    International Nuclear Information System (INIS)

    Yamamoto, Hiroko; Asano, Yasuhiko; Watanabe, Takatoshi; Hirao, Yoshitaka; Mizuno, Yasushi; Sobue, Itsuro

    1986-01-01

    Measurement of various parameters of supra- and infratentorial brain atrophy in computerized tomographs of 142 cases of spinocerebellar degeneration (SCD) and 100 age and sex matched controls was carried out in order to investigate whether these parameters would correspond to the subtypes of this disease and differing grades of various clinical manifestations. One supra- and all infratentorial parameters of SCD showed statistically significant atrophy with a risk of P < 0.005. Among the subtypes, OPCA had a more severely atrophied pons than LCCA (P < 0.005), Menzel (P < 0.05) and SSP (P < 0.01). There was a correlation between the distribution of symptoms like gait, speech, ataxia of extremities and ocular movement disorders, and distribution and degree of infratentorial atrophy with statistical significance (P < 0.05 ∼ P < 0.005). The degree of atrophy of the pons and the width of the IV ventricle were directly proportional to the duration of the illness in cases of less than 10 years, but not to those of over 10 years. Follow-up CT scan was done for 24 patients, 12 within 3 years, 12 after the lapse of 3 years. The latter group showed statistically significant atrophy between the 1st and 2nd scans in several parameters, but there was no significance between those of the former group. (author)

  14. Evaluation of supra- and infratentorial brain atrophy by computerized tomography in spinocerebellar degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Hiroko; Asano, Yasuhiko; Watanabe, Takatoshi; Hirao, Yoshitaka; Mizuno, Yasushi; Sobue, Itsuro

    1986-08-01

    Measurement of various parameters of supra- and infratentorial brain atrophy in computerized tomographs of 142 cases of spinocerebellar degeneration (SCD) and 100 age and sex matched controls was carried out in order to investigate whether these parameters would correspond to the subtypes of this disease and differing grades of various clinical manifestations. One supra- and all infratentorial parameters of SCD showed statistically significant atrophy with a risk of P < 0.005. Among the subtypes, OPCA had a more severely atrophied pons than LCCA (P < 0.005), Menzel (P < 0.05) and SSP (P < 0.01). There was a correlation between the distribution of symptoms like gait, speech, ataxia of extremities and ocular movement disorders, and distribution and degree of infratentorial atrophy with statistical significance (P < 0.05 -- P < 0.005). The degree of atrophy of the pons and the width of the IV ventricle were directly proportional to the duration of the illness in cases of less than 10 years, but not to those of over 10 years. Follow-up CT scan was done for 24 patients, 12 within 3 years, 12 after the lapse of 3 years. The latter group showed statistically significant atrophy between the 1st and 2nd scans in several parameters, but there was no significance between those of the former group.

  15. Bronchial asthma: correlation of high resolution computerized tomography findings with clinical data

    International Nuclear Information System (INIS)

    Mogami, Roberto; Marchiori, Edson; Kirk, Kennedy; Capone, Domenico; Daltro, Pedro

    1999-01-01

    In this work we did a sectional study of 31 asthmatic patients with several levels of disease severity, which were submitted to high resolution computed tomography of the thorax and spirometry, between the months of July, 1995 and August, 1997. The tomographic findings were correlated with the clinical classification of the patients and the most frequent tomographic findings were bronchial wall thickening, bronchial dilatation, air trapping, centrilobular opacities, cicatricial linear shadows, mucoid impaction, emphysema and atelectasis. In asthmatic patients of long duration we observed small airway disease and irreversible lesions as the predominant findings. In smoking patients there was no high frequency of emphysema. (author)

  16. Findings of cranial computerized tomography in chronic schizophrenics with and without tardive dyskinesias

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, N.U.

    1985-11-25

    Findings of cranial computed tomography in 20 chronic schizophrenics with clinical distinct, long-dated hyperkinesias (tardive dyskinesias) are compared with those of a similar group of schizophrenics without hyperkinesias. Both groups had a long-term neuroleptic treatment. The tomograms of those patients with tardive dyskinesias showed only in two cases mild, pathological alterations. Also the tomograms of the comparative group showed no severe atrophies, defects of substance or pathological calcifications. It is concluded that there is no correlation between tardive dyskinesias in long-term neuroleptic treated schizophrenics and gross morphological alterations of the brain. Furthermore the problem of tardive dyskinesia in a general aspect is discussed. (orig.).

  17. The usefulness of computerized tomography in the evaluation of cardio phrenic angle lesion

    International Nuclear Information System (INIS)

    Marins, J.L.; Cazerta, N.M.G.; Prando, A.; Pereira, R.M.

    1988-01-01

    The usefulness of computed tomography (CT) in categorizing lesions of the cardio phrenic angles is showed. Twenty five patients with abnormalities in these sites were studied by CT. These abnormalities included ten cases of lymphomatous adenopathy, two cases of metastatic adenopathy, four cases of pericardial cyst, four cases of loculated pleural effusion, and five cases of prominent epicardial fat. A correct evaluation of all cases was possible by utilizing the CT densities numbers and the topographic characteristics of the lesions. CT showed high sensitivity in detecting paracardiac adenopathy which may affect the staging and treatment of neoplasia. (author)

  18. A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: An in vitro study

    OpenAIRE

    Vivek Gaurav; Nikhil Srivastava; Vivek Rana; Vivek Kumar Adlakha

    2013-01-01

    Background: Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. Aim: The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. Settings and Design: A total ...

  19. Dose profile study on computerized tomography scanning of skull with simulator object; Estudo do perfil de dose em varreduras de TC de cranio com objeto simulador

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, A.P., E-mail: aprata@des.cefetmg.b [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar; Alonso, Thessa C.; Silva, Teogenes A. da, E-mail: alonso@cdtn.b, E-mail: silvata@@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-10-26

    This work presents a comparison among the dose profiles in scanning of computerized tomography of a simulator object of PMMA in its periphery region. To obtain the deposited dose at the PMMA thermoluminescent dosemeters were used positioned at the interior of PMMA simulated object longitudinal to periphery and at the center of cylinder (positions denominated North, South, East, West and Center). Eight scanning were performed of simulator object using the routine protocol for skull in eight different services of radiodiagnostic by TC

  20. 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

  1. Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography, magnetic resonance imaging, and positron emission tomography

    International Nuclear Information System (INIS)

    Romero, J.A.; Kim, E.E.; Tresukosol, D.; Kudelka, A.P.; Edwards, C.L.; Kavanagh, J.J.

    1995-01-01

    We report a case of recurrent endodermal sinus tumor of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed. (orig.)

  2. Staging of pharyngeal cancer by computerized tomography during phonation. Comparison of CT findings with endoscopy and pharyngography

    International Nuclear Information System (INIS)

    Warmuth-Metz, M.; Feyerabend, T.; Schmitt, R.; Richter, E.

    1989-01-01

    46 patients with histologically proven carcinoma of the oro- and/or hypopharynx underwent clinical and endoscopic examination as well as double-contrast-pharyngography and computerized tomography (CT). The results of the different diagnostic procedures according to the TNM-classification (UICC) were compared with each other. Additional information by CT was obtained in 40% of cases. In 30%, the TNM-classification had to be changed up to one or even up to two T-categories. Major improvement of the CT-evaluation of carcinoma of the pharynx can be achieved by the additional use of CT during phonation: in our study 50% of pharyngeal cancers were thus better delimited in their extent and relations to the surrounding anatomical structures. Especially for the evaluation of the base of the tongue, the hypopharynx and the epiglottis CT during phonation (similar to the use of the double-contrast technique in pharyngography) is superior to CT at rest because the anatomy of the pharynx and therefore the extent of a mass is much better demonstrated. (orig.) [de

  3. Temporal evolution of hypoxic-ischiaemic brain lesions in asphyxiated full-term newborns as assessed by computerized tomography

    International Nuclear Information System (INIS)

    Lipp-Zwahlen, A.E.; Zurich Univ.; Deonna, T.; Micheli, J.L.; Calame, A.; Chrzanowski, R.

    1985-01-01

    Hypoxic-ischaemic brain lesions may be detected as low density (LD) areas by means of computerized tomography (CT), but the clinical significance of such LD areas has been controversial. Since timing might be a critical factor, we studied the temporal evolution of LD areas in 9 asphyxiated term babies who had two or more CT, and compared the changes to the neurodevelopmental outcome. Scans were classified according to the elapsed time after asphyxia as early (day 1-7, n=6), intermediate (week 2-4, n=7; week 4-7, n=3) and late CT (3 months or more, n=7). In early scans, no, or only ill defined, LD areas were seen in the periventricular region. In intermediate CT's, LD-zones were further diminshed in those babies who later were normal. Sharply accentuated LD areas, however appeared in those who later suffered from neurodevelopmental disorders. These LD areas, probably representing hypoxic-ischaemic lesions, were located periventricularly, extending into the subcortical white matter and the cortex. They began to disappear at 4 to 7 weaks in some regions. LD persisting more than 4-7 weeks tended to transform into cyst-like lesions, or marked atrophy. We conclude (1) that hypoxic-ischaemic lesions appear as zones of low density on CT scans performed after the first week and (2) that the extent of such lesions can best be assessed between 9 to 23 days after asphyxia. (orig./GSH)

  4. Temporal evolution of hypoxic-ischiaemic brain lesions in asphyxiated full-term newborns as assessed by computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lipp-Zwahlen, A.E.; Deonna, T.; Micheli, J.L.; Calame, A.; Chrzanowski, R.

    1985-03-01

    Hypoxic-ischemic brain lesions may be detected as low density (LD) areas by means of computerized tomography (CT), but the clinical significance of such LD areas has been controversial. Since timing might be a critical factor, the temporal evolution of LD areas was studied in 9 asphyxiated term babies who had two or more CT, and the changes were compared to the neurodevelopmental outcome. Scans were classified according to the elapsed time after asphyxia as early (day 1-7, n=6), intermediate (week 2-4, n=7; week 4-7, n=3) and late CT (3 months or more, n=7). In early scans, no, or only ill defined, LD areas were seen in the periventricular region. In intermediate CT's, LD-zones were further diminshed in those babies who later were normal. Sharply accentuated LD areas, however appeared in those who later suffered from neurodevelopmental disorders. These LD areas, probably representing hypoxic-ischemic lesions, were located periventricularly, extending into the subcortical white matter and the cortex. They began to disappear at 4 to 7 weaks in some regions. LD persisting more than 4-7 weeks tended to transform into cyst-like lesions, or marked atrophy. The authors conclude (1) that hypoxic-ischemic lesions appear as zones of low density on CT scans performed after the first week and (2) that the extent of such lesions can best be assessed between 9 to 23 days after asphyxia.

  5. Non-contrast computerized tomography (NCCT) and dynamic renal scintigraphy (DRS) in the patients with refractory renal colic

    International Nuclear Information System (INIS)

    Kravchick, Sergey; Stepnov, Eugeny; Lebedev, Valery; Linov, Lina; Leibovici, Octavian; Ben-Horin, Clara L. Dosoretz; Trejo, Leonardo; Peled, Ronit; Cytron, Shmuel

    2006-01-01

    Objectives: To assess the importance of combined use of non-contrast computerized tomography (NCCT) and dynamic renal scintigraphy (DRS) in evaluation of patients with refractory flank pain in the emergency department. Methods: The study involved 64 consecutive patients with refractory renal colic. All patients were evaluated with plain abdominal films kidneys, ureters and bladder (KUB), NCCT and DRS. We assessed the accuracy of different diagnostic procedures and their combinations; in addition, we determined their importance for different steps of evaluation. Results: Urololithiasis was diagnosed in 76.6% (n = 49) of the patients. Twenty-nine percent of calculi were >4 mm. Surgical intervention were performed in 20 patients (40.8%). A combination of NCCT plus DRS yielded the greatest sensitivity (96%) in establishing final diagnosis, however clinical, laboratory and KUB data in combination with DRS, yielded greater specificity (93%) and PPV (97%). Sex (male), WBC (mean 10.2 x 10 3 ± 3.1) and KUB (calculus > 4 mm) were chosen in the three-step multi-variant analysis, while only male sex was found to be the strongest predictor (p 3 and calculi > 4 mm on the KUB

  6. Mapping local cerebral blood flow by means of computerized tomography with a short inhalation of low-dose stable xenon

    International Nuclear Information System (INIS)

    Nakagawara, Jyoji; Karasawa, Jun; Tasawa, Toshiaki; Touho, Hajime; Nakauchi, Mikio; Kagawa, Masa-aki; Asai, Masa-aki; Kuriyama, Yoshihiro; Kikuchi, Haruhiko.

    1986-01-01

    A non-invasive technique has been developed for mapping the local blood-brain partition coefficient (λi), the local build-up rate constant (κi), and the local cerebral blood flow (l-CBF) by means of xenon-enhanced computerized tomography (CT) using a YMS CT 9000 scanner. After denitrogenation for 10 minutes, a 30 % xenon/oxygen mixture is inhaled for 4 - 8 minutes through a rubber face-mask and a delivery system of stable xenon. The time course of local cerebral CT enhancement is utilized in order to calculate, the λi, κi, and l-CBF values. The CT enhancement data during the washin-washout phase are fitted to the mathematical functions, based on Kety's formula, using least-squares curve-fitting analysis. Several case studies of patients with cerebral vascular accidents are presented to demonstrate the characterization of the λi and l-CBF patterns in various tissues; the results are of sufficient quality for the management of patients. The theoretical assumptions underlying stable xenon CT CBF measurements are discussed. (author)

  7. Technetium-99m-HMPAO labeled leukocyte single photon emission computerized tomography (SPECT) for assessing Crohn's disease extent and intestinal infiltration.

    Science.gov (United States)

    Biancone, L; Schillaci, O; Capoccetti, F; Bozzi, R M; Fina, D; Petruzziello, C; Geremia, A; Simonetti, G; Pallone, F

    2005-02-01

    Scintigraphy using radiolabeled leukocytes is a useful technique for assessing intestinal infiltration in Crohn's disease (CD). However, limits of planar images include overlapping activity in other organs and low specificity. To investigate the usefulness of (99m)Tc-HMPAO (hexametyl propylene amine oxime) labeled leukocyte single photon emission computerized tomography (SPECT) for assessing CD lesions, in comparison with planar images. Twenty-two inflammatory bowel disease patients (19 CD; 2 ulcerative colitis, UC; 1 ileal pouch) assessed by conventional endoscopy or radiology were enrolled. Leukocytes were labeled with (99m)Tc-HMPAO. SPECT images were acquired at 2 h and planar images at 30 min and 2 h. Bowel uptake was quantitated in nine regions (score 0-3). Both SPECT and planar images detected a negative scintigraphy (score 0) in the UC patient with no pouchitis and a positive scintigraphy (score 1-3) in the 21 patients showing active inflammation by conventional techniques. SPECT showed a higher global score than planar images (0.71 +/- 0.09 vs 0.30 +/- 0.05; p < 0.001), and in particular in the right iliac fossa (p= 0.003), right and left flank (p < 0.001; p= 0.02), hypogastrium (p= 0.002), and mesogastrium (p < 0.001). SPECT provided a better visualization and a higher uptake than planar images in patients with ileal and ileocolonic CD (6.45 +/- 0.82 vs 2.8 +/- 0.55, p < 0.001; 5.5 +/- 1.6 vs 2.6 +/- 0.7, p= 0.03), and with perianal CD (6.6 +/- 1.6 vs 3.4 +/- 1.2; p= 0.03). (99m)Tc-HMPAO labeled leukocyte SPECT provides a more detailed visualization of CD lesions than planar images. This technique may better discriminate between intestinal and bone marrow uptake, thus being useful for assessing CD lesions within the pelvis, including perianal disease.

  8. Pocket book on setting techniques for medical imaging. X-ray diagnostics, angiography, CT, MRT. 4. rev. and enl. ed.; Taschenatlas Einstelltechnik. Roentgendiagnostik, Angiografie, CT, MRT

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Torsten B.; Reif, Emil [Caritas-Krankenhaus, Dillingen/Saar (Germany)

    2009-07-01

    The pocketbook on setting techniques for medical imaging is concerned with the problem to prepare appropriate images for diagnostic purposes using modern high-technology instruments like x-ray diagnostics, angiography, computerized tomography and magnetic resonance tomography. The following issues are covered: Head, spinal column, upper extremities, lower extremities, thorax, gastrointestinal tract, intravenous organ examination, angiography, computerized tomography, NMR imaging.

  9. Cranial computerized tomography. A synoptical atlas. Kranielle Computertomographie. Ein synoptischer Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Nadjmi, M; Piepgras, U; Vogelsang, H

    1981-01-01

    The introductory chapters of the book cover, insofar as they differ from conventional radiology, the physico-technical fundamentals, the investigative procedure, as well as the anatomy and pathology. The anatomic pathology and classic neuroradiology of the individual groups are described in each chapter. These descriptions form the basis for interpreting the results obtained with computed tomography. This synoptical presentation makes it possible for non-neuroradiologists to obtain an overall impression on an often heterogeneous subject. The chapter on tumors also covers tumors in infants and children. The chapters on inflammatory diseases, traumatology and orbita include coverage of all age groups. The chapter of neuropediatrics deals mainly with the aspects of birth trauma and abnormal development. The legends to the illustrations comprise clinical data insofar as they contribute to a didactically important synthesis between syndrome, diagnosis and therapy.

  10. Computerized tomography in the Community of Madrid. Techniques used in the studies

    International Nuclear Information System (INIS)

    Ruiz Sanz, S.; Calzado, S.; Rodriguez, R.; Melchor, M.

    1994-01-01

    The main object of the present work was the knowledge of technique and geometrical factors most frequently used to perform computed tomography (CT) examinations in health centres of the Community of Madrid. A sample of actual examinations to patient in several CT rooms was taken. In this way up to about 1500 individual values of technique factors data (kVp, mAs, slice thickness, couch increment and number of slices) were recorded. Mean values and ranges of such parameters are given for each examination type. Mean values for each scanner are analysed and the average mAs are compared to those recommended by the manufacturer for two types of examination (head and abdomen). The number of ''series of slices'' used to perform the examination was also analysed. (Author) 4 refs

  11. X-ray computerized tomography used in non-destructive testing of aerospace materials

    International Nuclear Information System (INIS)

    Maschio, Celio; Alencar Lotufo, Roberto de

    1996-01-01

    This work reports the development of nondestructive testing procedures for aerospace materials, using a medical tomograph (80 to 150 KeV), associated to the image digital processing techniques through the KHOROS system

  12. New imaging algorithm in diffusion tomography

    Science.gov (United States)

    Klibanov, Michael V.; Lucas, Thomas R.; Frank, Robert M.

    1997-08-01

    A novel imaging algorithm for diffusion/optical tomography is presented for the case of the time dependent diffusion equation. Numerical tests are conducted for ranges of parameters realistic for applications to an early breast cancer diagnosis using ultrafast laser pulses. This is a perturbation-like method which works for both homogeneous a heterogeneous background media. Its main innovation lies in a new approach for a novel linearized problem (LP). Such an LP is derived and reduced to a boundary value problem for a coupled system of elliptic partial differential equations. As is well known, the solution of such a system amounts to the factorization of well conditioned, sparse matrices with few non-zero entries clustered along the diagonal, which can be done very rapidly. Thus, the main advantages of this technique are that it is fast and accurate. The authors call this approach the elliptic systems method (ESM). The ESM can be extended for other data collection schemes.

  13. Review methods for image segmentation from computed tomography images

    International Nuclear Information System (INIS)

    Mamat, Nurwahidah; Rahman, Wan Eny Zarina Wan Abdul; Soh, Shaharuddin Cik; Mahmud, Rozi

    2014-01-01

    Image segmentation is a challenging process in order to get the accuracy of segmentation, automation and robustness especially in medical images. There exist many segmentation methods that can be implemented to medical images but not all methods are suitable. For the medical purposes, the aims of image segmentation are to study the anatomical structure, identify the region of interest, measure tissue volume to measure growth of tumor and help in treatment planning prior to radiation therapy. In this paper, we present a review method for segmentation purposes using Computed Tomography (CT) images. CT images has their own characteristics that affect the ability to visualize anatomic structures and pathologic features such as blurring of the image and visual noise. The details about the methods, the goodness and the problem incurred in the methods will be defined and explained. It is necessary to know the suitable segmentation method in order to get accurate segmentation. This paper can be a guide to researcher to choose the suitable segmentation method especially in segmenting the images from CT scan

  14. Optical coherence tomography in anterior segment imaging

    Science.gov (United States)

    Kalev-Landoy, Maya; Day, Alexander C.; Cordeiro, M. Francesca; Migdal, Clive

    2008-01-01

    Purpose To evaluate the ability of optical coherence tomography (OCT), designed primarily to image the posterior segment, to visualize the anterior chamber angle (ACA) in patients with different angle configurations. Methods In a prospective observational study, the anterior segments of 26 eyes of 26 patients were imaged using the Zeiss Stratus OCT, model 3000. Imaging of the anterior segment was achieved by adjusting the focusing control on the Stratus OCT. A total of 16 patients had abnormal angle configurations including narrow or closed angles and plateau irides, and 10 had normal angle configurations as determined by prior full ophthalmic examination, including slit-lamp biomicroscopy and gonioscopy. Results In all cases, OCT provided high-resolution information regarding iris configuration. The ACA itself was clearly visualized in patients with narrow or closed angles, but not in patients with open angles. Conclusions Stratus OCT offers a non-contact, convenient and rapid method of assessing the configuration of the anterior chamber. Despite its limitations, it may be of help during the routine clinical assessment and treatment of patients with glaucoma, particularly when gonioscopy is not possible or difficult to interpret. PMID:17355288

  15. Brain dopaminergic systems : imaging with positron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C [University of Caen/INSERM U, Caen (France). CYCERON; Comar, D [E.E.C. Concerted Action on P.E.T. Investigations of Cellular Regeneration and Degeneration, Orsay (France) CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot; Farde, L [Karolinska Sjukhuset, Stockholm (Sweden); Martinot, J L; Mazoyer, B [CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot Paris-

    1991-01-01

    Imaging of the dopaminergic system in the human brain with the in vivo use of Positron Emission Tomography emerged in the late 1980s as a tool of major importance in clinical neurosciences and pharmacology. The last few years have witnessed rapid development of new radiotracers specific to receptors, reuptake sites and enzymes of the dopamine system; the application of these radiotracers has led to major break-troughs in the pathophysiology and therapy of movement disorders and schizophrenic-like psychoses. This book is the first to collect, in a single volume, state-of-the-art contributions to the various aspects of this research. Its contents address methodological issues related to the design, labelling, quantitative imaging and compartmental modeli-sation of radioligands of the post-synaptic, pre-synaptic and enzyme sites of the dopamine system and to their use in clinical research in the fields of Parkinson's disease as well as other movement disorders, psychoses and neuroleptic receptor occupancy. The chapters were written by leading European scientists in the field of PET, gathered together in Caen (France, November 1990) under the aegis of the EEC Concerted Action on PET Investigations of Cellular Regeneration and Degeneration. This book provides a current and comprehensive overview on PET studies of the brain dopamine system which should aid and interest neurologists , psychiatrists, pharmacologists and medical imaging scientists. (author). refs.; figs.; tabs.

  16. Computed tomography with selectable image resolution

    International Nuclear Information System (INIS)

    Dibianca, F.A.; Dallapiazza, D.G.

    1981-01-01

    A computed tomography system x-ray detector has a central group of half-width detector elements and groups of full-width elements on each side of the central group. To obtain x-ray attenuation data for whole body layers, the half-width elements are switched effectively into paralleled pairs so all elements act like full-width elements and an image of normal resolution is obtained. For narrower head layers, the elements in the central group are used as half-width elements so resolution which is twice as great as normal is obtained. The central group is also used in the half-width mode and the outside groups are used in the full-width mode to obtain a high resolution image of a body zone within a full body layer. In one embodiment data signals from the detector are switched by electronic multiplexing and in another embodiment a processor chooses the signals for the various kinds of images that are to be reconstructed. (author)

  17. Automated computerized scheme for distinction between benign and malignant solitary pulmonary nodules on chest images

    International Nuclear Information System (INIS)

    Aoyama, Masahito; Li Qiang; Katsuragawa, Shigehiko; MacMahon, Heber; Doi, Kunio

    2002-01-01

    A novel automated computerized scheme has been developed to assist radiologists for their distinction between benign and malignant solitary pulmonary nodules on chest images. Our database consisted of 55 chest radiographs (33 primary lung cancers and 22 benign nodules). In this method, the location of a nodule was indicated first by a radiologist. The difference image with a nodule was produced by use of filters and then represented in a polar coordinate system. The nodule was segmented automatically by analysis of contour lines of the gray-level distribution based on the polar-coordinate representation. Two clinical parameters (age and sex) and 75 image features were determined from the outline, the image, and histogram analysis for inside and outside regions of the segmented nodule. Linear discriminant analysis (LDA) and knowledge about benign and malignant nodules were used to select initial feature combinations. Many combinations for subgroups of 77 features were evaluated as input to artificial neural networks (ANNs). The performance of ANNs with the selected 7 features by use of the round-robin test showed Az=0.872, which was greater than Az=0.854 obtained previously with the manual method (P=0.53). The performance of LDA (Az=0.886) was slightly improved compared to that of ANNs (P=0.59) and was greater than that of the manual method (Az=0.854) reported previously (P=0.40). The high level of its performance indicates the potential usefulness of this automated computerized scheme in assisting radiologists as a second opinion for distinction between benign and malignant solitary pulmonary nodules on chest images

  18. 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.)

  19. Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Thines, Laurent [Lille University Hospital, Department of Neurosurgery, Lille (France); Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Agid, Ronit; Da Costa, Leodante; Terbrugge, Karel G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Dehdashti, Amir R.; Wallace, M.C.; Tymianski, Michael [Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada)

    2009-08-15

    Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

  20. Evaluation of a new pencil-type ionization chamber for dosimetry in computerized tomography beams

    International Nuclear Information System (INIS)

    Castro, Maysa C. de; Neves, Lucio P.; Silva, Natalia F. da; Santos, William de S.; Caldas, Linda V.E.

    2014-01-01

    For performing dosimetry in computed tomography beams (CT), use is made of a pencil-type ionization chamber, since this has a uniform response to this type of beam. The common commercial chambers in Brazil have a sensitive volume length of 10 cm. Several studies of prototypes of this type of ionization chamber have been conducted, using different materials and geometric configurations, in the Calibration Laboratory Instruments of the Institute of Nuclear and Energy Research (LCI) and these showed results within internationally acceptable limits. These ion chambers of 10 cm are widely used nowadays, however studies have revealed that they have underestimated the dose values. In order to solve this problem, we developed a chamber with sensitive volume length of 30 cm. As these are not yet very common and no study has yet been performed on LCI conditions on their behavior, is important that the characteristics of these dosemeters are known, and the influence of its various components. For your review, we will use the Monte Carlo code Penelope, freely distributed by the IAEA. This method has revealed results consistent with other codes. The results for this new prototype can be used in dosimetry of the CT of the hospitals and calibration laboratories as the LCI

  1. Preliminary tests in skull pediatric phantom for dosimetry in computerized tomography

    International Nuclear Information System (INIS)

    Martins, Elaine Wirney; Potiens, Maria da Penha de A.

    2014-01-01

    Computed tomography (CT) is one of the techniques in the field of radiology with striking technological advance in recent years. One reason for this was the increased number of channels associated with the increased power of the X-ray tube. These conditions allowed the equipment high speed in the acquisition of the cuts, reducing the patient exposure time essential characteristic for the increase of its use in pediatric patients. In this context, were developed a new pediatric skull simulator to analyze the results of measurements performed in laboratory and clinic beams with the objective of creation and use of diagnostic reference levels observing risks stochastic effects and assessing the reduction of absorbed doses in patients undergoing growing. Preliminary tests performed in clinical beams showed C w values: 2.525 ± 0.212 mGy for the developed simulator quoted and 3.362 ± 0.282 mGy for a simulator developed by IPEN called standard, both being between uncertainty values of 8.4% and 14.4% suggested by TRS number 457

  2. Optimization of protocol in computerized tomography scans of children's chest

    International Nuclear Information System (INIS)

    Lima, L.T.A.; Roberto, W. dos S.; Mourão Filho, A.P.

    2017-01-01

    The diffusion of the Computed Tomography (CT) has promoted a significant increase of the dose absorbed by patients. This technique showed a high growth as a result of clinical cases of medical emergencies, neoplasia and pediatric traumas. The risks of stochastic effects are greater for children due to tissue radiosensitivity coupled with longer life expectancy. In the present work, a cylindrical simulator was used, representing an adult thorax made of polymethylmethacrylate (PMMA), and a second simulator object of the same material was developed in oblong format including the axillary regions, based on the dimensions of the patient's thorax one-year-old pediatric population. The scanning on the adult simulator object was performed with the chest radiograph diagnostic service with a 120 kV supply voltage and in the pediatric simulator object were performed optimized scans with 120, 100 and 80 kV. This work compared the dose variation absorbed by the pediatric simulator object mentioned by the change in the tube supply voltage

  3. Image processing tensor transform and discrete tomography with Matlab

    CERN Document Server

    Grigoryan, Artyom M

    2012-01-01

    Focusing on mathematical methods in computer tomography, Image Processing: Tensor Transform and Discrete Tomography with MATLAB(R) introduces novel approaches to help in solving the problem of image reconstruction on the Cartesian lattice. Specifically, it discusses methods of image processing along parallel rays to more quickly and accurately reconstruct images from a finite number of projections, thereby avoiding overradiation of the body during a computed tomography (CT) scan. The book presents several new ideas, concepts, and methods, many of which have not been published elsewhere. New co

  4. Massive training artificial neural network (MTANN) for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Armato, Samuel G. III; Li, Feng; Sone, Shusuke; Doi, Kunio

    2003-01-01

    In this study, we investigated a pattern-recognition technique based on an artificial neural network (ANN), which is called a massive training artificial neural network (MTANN), for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography (CT) images. The MTANN consists of a modified multilayer ANN, which is capable of operating on image data directly. The MTANN is trained by use of a large number of subregions extracted from input images together with the teacher images containing the distribution for the 'likelihood of being a nodule'. The output image is obtained by scanning an input image with the MTANN. The distinction between a nodule and a non-nodule is made by use of a score which is defined from the output image of the trained MTANN. In order to eliminate various types of non-nodules, we extended the capability of a single MTANN, and developed a multiple MTANN (Multi-MTANN). The Multi-MTANN consists of plural MTANNs that are arranged in parallel. Each MTANN is trained by using the same nodules, but with a different type of non-nodule. Each MTANN acts as an expert for a specific type of non-nodule, e.g., five different MTANNs were trained to distinguish nodules from various-sized vessels; four other MTANNs were applied to eliminate some other opacities. The outputs of the MTANNs were combined by using the logical AND operation such that each of the trained MTANNs eliminated none of the nodules, but removed the specific type of non-nodule with which the MTANN was trained, and thus removed various types of non-nodules. The Multi-MTANN consisting of nine MTANNs was trained with 10 typical nodules and 10 non-nodules representing each of nine different non-nodule types (90 training non-nodules overall) in a training set. The trained Multi-MTANN was applied to the reduction of false positives reported by our current computerized scheme for lung nodule detection based on a database of 63 low-dose CT scans (1765

  5. Utility of mobile devices in the computerized tomography evaluation of intracranial hemorrhage

    International Nuclear Information System (INIS)

    Panughpath, Sridhar G; Kumar, Savith; Kalyanpur, Arjun

    2013-01-01

    To evaluate the utility of a mobile device to detect and assess intracranial hemorrhage (ICH) on head computed tomographys (CT) performed in the emergency setting. 100 head CT scans were randomly selected from our emergency radiology database and anonymized for patient demographics and clinical history. The studies were independently interpreted by two experienced radiologists in a blinded manner, initially on a mobile device (iPad, Apple computers) and subsequently, at an interval of one week, on a regular desktop workstation. Evaluation was directed towards detection, localization and characterization of hemorrhage. The results were assessed for accuracy, sensitivity, specificity and positive predictive value. Statistical significance was ascertained using Fisher's exact test. 27 of the examinations were positive for ICH, of which 11 had multiple hemorrhages. Of these there were 17 subdural, 18 intraparenchymal, 8 subarachnoid, 4 intraventricular and 2 extradural hemorrhages. In 96 of the studies there was complete concurrence between the iPad and desktop interpretations for both radiologists. Of 49 hemorrhages, 48 were accurately detected on the iPad by one of the radiologists. In the remaining case, a tiny intraventricular hemorrhage was missed by both radiologists on the iPad as well as on the workstation, indicating that the miss was more likely related to the very small size of the hemorrhage than the viewer used. We conclude that in the emergency setting, a mobile device with appropriate web-based pictue archiving and communication system (PACS) is effective in the detection of intracranial hemorrhage present on head CT

  6. Utility of mobile devices in the computerized tomography evaluation of intracranial hemorrhage

    Directory of Open Access Journals (Sweden)

    Sridhar G Panughpath

    2013-01-01

    Full Text Available Aim: To evaluate the utility of a mobile device to detect and assess intracranial hemorrhage (ICH on head computed tomographys (CT performed in the emergency setting. Materials and Methods: 100 head CT scans were randomly selected from our emergency radiology database and anonymized for patient demographics and clinical history. The studies were independently interpreted by two experienced radiologists in a blinded manner, initially on a mobile device (iPad, Apple computers and subsequently, at an interval of one week, on a regular desktop workstation. Evaluation was directed towards detection, localization and characterization of hemorrhage. The results were assessed for accuracy, sensitivity, specificity and positive predictive value. Statistical significance was ascertained using Fisher′s exact test. Results: 27 of the examinations were positive for ICH, of which 11 had multiple hemorrhages. Of these there were 17 subdural, 18 intraparenchymal, 8 subarachnoid, 4 intraventricular and 2 extradural hemorrhages. In 96 of the studies there was complete concurrence between the iPad and desktop interpretations for both radiologists. Of 49 hemorrhages, 48 were accurately detected on the iPad by one of the radiologists. In the remaining case, a tiny intraventricular hemorrhage was missed by both radiologists on the iPad as well as on the workstation, indicating that the miss was more likely related to the very small size of the hemorrhage than the viewer used. Conclusion: We conclude that in the emergency setting, a mobile device with appropriate web-based pictue archiving and communication system (PACS is effective in the detection of intracranial hemorrhage present on head CT.

  7. Dose assessment in pediatric computerized tomography; Avaliacao de doses em tomografia computadorizada pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Vilarinho, Luisa Maria Auredine Lima

    2004-07-01

    The objective of this work was the evaluation of radiation doses in paediatric computed tomography scans, considering the high doses usually involved and the absence of any previous evaluation in Brazil. Dose values were determined for skull and abdomen examinations, for different age ranges, by using the radiographic techniques routinely used in the clinical centers investigated. Measurements were done using pencil shape ionization chambers inserted in polymethylmethacrylate (PMMA) phantoms. These were compact phantoms of different diameters were specially designed and constructed for this work, which simulate different age ranges. Comparison of results with published values showed that doses were lower than the diagnostic reference levels established to adults exams by the European Commission. Nevertheless, doses in paediatric phantoms were higher than those obtained in adult phantoms. The paediatric dose values obtained in Hospitals A and B were lower than the reference level (DRL) adopted by SHIMPTON for different age ranges. In the range 0 - 0.5 year (neonatal), the values of DLP in Hospital B were 94 por cent superior to the DRL For the 10 years old children the values of CTDI{sub w} obtained were inferior in 89 por cent for skull and 83 por cent for abdomen examinations, compared to the values published by SHRIMPTON and WALL. Our measured CTDI{sub w} values were inferior to the values presented for SHRIMPTON and HUDA, for all the age ranges and types of examinations. It was observed that the normalized dose descriptors values in children in the neonatal range were always superior to the values of doses for the adult patient. In abdomen examinations, the difference was approximately 90% for the effective dose (E) and of 57%.for CTDI{sub w} . (author)

  8. Optimum quantization and interpolation of projections in X-ray computerized tomography

    International Nuclear Information System (INIS)

    Vajnberg, Eh.I.; Fajngojz, M.L.

    1984-01-01

    Two methods to increase the accuracy of image reconstruction due to optimization of quantization and interpolation of proections with separate reduction of the main types of errors are described and experimentally studied. A high metrological and calculation efficiency of increasing the count frequency in the reconstructed tomogram 2-4 times is found. The optimum structure of interpolation functions of a minimum extent is calculated

  9. Number and location of hepatic malignant lesions by computerized tomography-angiography

    International Nuclear Information System (INIS)

    Llauger, J.; Perez, C.; Castaner, E.; Coscojuela, P.; Marcos, J.A.; Pallardo, Y.; Traid, C.; Zidan, A.

    1991-01-01

    In order to perform surgical treatment of tumorous hepatic disease, primary or metastatic, the most accurate knowledge as possible of the number and location of lesions is needed. In that way, results provided by echography and conventional CT are not much precise, showing lasser that 60% of lessions. In this study CT-angiography technique, its indications, results and images obtained by this method are described. (Author)

  10. Kimura's disease: imaging patterns on computed tomography

    International Nuclear Information System (INIS)

    Gopinathan, Anil; Tan, T.Y.

    2009-01-01

    Aim: To define the role of computed tomography (CT) in identifying and classifying the imaging patterns of diagnostic value in Kimura's disease of the head and neck. Methods: A retrospective study was undertaken comprising 13 patients with histopathological evidence of Kimura's disease. The patients' clinical and pathological records were reviewed against a detailed analysis of their CT images performed from the base of the skull to the arch of the aorta. Results: Both well-defined, nodular masses, as well as ill-defined plaque-like infiltrative masses were seen in the subcutaneous tissue of the head and neck region. All patients had lesions adjacent to the major salivary glands. The parotid gland was affected in 10 of the 13 cases and the submandibular gland was affected in the rest. Contrast enhancement was variable. More than half of the cases had associated lymphadenopathy. Some of them showed atrophy of the skin and subcutaneous fat overlying the subcutaneous masses. Blood eosinophilia was a consistent feature in all the cases. Conclusion: The patterns of distribution, morphology, and enhancement of the lesions in Kimura's disease that can be demonstrated at CT, enables a confident, non-invasive diagnosis of this condition, in an appropriate clinical context.

  11. High Speed impedance tomography for cardiac imaging

    International Nuclear Information System (INIS)

    Tehrani, J.N.; Jin, C.; Schaik, Andre

    2010-01-01

    Full text: Electrical Impedance Tomography (EIT) calculates the internal conductivity distribution within a body using electrical contact measurements. Previous investigation has shown that optimizing electrode placement can give better information about the stroke volume and better separation between the ventricles and atria than with the electrodes attached in the transverse plane. In our investigation we are developing fast three dimensional imaging of the heart (two planes of 16 electrodes) including internal electrodes in esophagus. The reconstruction speed in EIT is one of the main limitations for real time imaging when using a detailed three dimensional finite element mesh. For that reason we investigated new iterative algorithms for solving large scale LJ regularization. In this research we compare these algorithms on noise reliability and speed for 2D cardiac models. The four methods were as follows: (I) an interior point method for solving Ll-regularized least squares problems (Ll-LS); (2) total variation using a Lagrangian multiplier (TV AL3); (3) a two step iterative shrinkage/thresholding method (TWIST) for solving the Lo-regularized least squares problem; (4) The Least Absolute Shrinkage and Selection Operator (LASSO). In our investigation, using 1600 elements, we found all four algorithms provided an improvement over the best conventional EIT reconstruction method, Total Variation, in three important areas: robustness to noise, increased computational speed of at least 40 x and a visually apparent improvement in spatial resolution. Out of the four algorithms we found TWIST was the fastest with at least a 1 00 x speed increase. (author)

  12. Improved algorithm for computerized detection and quantification of pulmonary emphysema at high-resolution computed tomography (HRCT)

    Science.gov (United States)

    Tylen, Ulf; Friman, Ola; Borga, Magnus; Angelhed, Jan-Erik

    2001-05-01

    Emphysema is characterized by destruction of lung tissue with development of small or large holes within the lung. These areas will have Hounsfield values (HU) approaching -1000. It is possible to detect and quantificate such areas using simple density mask technique. The edge enhancement reconstruction algorithm, gravity and motion of the heart and vessels during scanning causes artefacts, however. The purpose of our work was to construct an algorithm that detects such image artefacts and corrects them. The first step is to apply inverse filtering to the image removing much of the effect of the edge enhancement reconstruction algorithm. The next step implies computation of the antero-posterior density gradient caused by gravity and correction for that. Motion artefacts are in a third step corrected for by use of normalized averaging, thresholding and region growing. Twenty healthy volunteers were investigated, 10 with slight emphysema and 10 without. Using simple density mask technique it was not possible to separate persons with disease from those without. Our algorithm improved separation of the two groups considerably. Our algorithm needs further refinement, but may form a basis for further development of methods for computerized diagnosis and quantification of emphysema by HRCT.

  13. A study on the clinical utilization of cranial computerized tomography: reasons and costs

    International Nuclear Information System (INIS)

    Oliveira, A.T.R. de

    1992-01-01

    It was reviewed a series of 2860 cerebral computed tomography (CCT) in order to compare the main reasons at referral to investigation with the CCT results and the costs with normal and abnormal CCT. It was also studied the age and sex of the patients. Data were collected from one out of three diagnostic centers in Salvador, Brasil, for a three years period. The 2860 CCT exclude all investigation carried out for the follow-up of a previously diagnosed abnormality. CCT abnormalities were detected in 1152 (40.3%). The following reasons showed the highest proportion of abnormal CCT, for males and females respectively: demential syndrome (91.7 and 83.3%); cerebrovascular accidents (85.1 and 73.6%); infectious and parasital diseases (76.5 and 78.6%); tumors (65.8 and 55.4%); and head injuries, 63.6% for males. In the female group, 65.0% of the CCT were normal, in a range of 65.0 to 80.0% for the age groups under 54 years old. In the male group, the highest proportion of normal CCT was found in the age groups: 25-34 (68.4%), <15 (62.9%) and 35-44 (62.7%). The most common reasons for normal CCT for males and females were: headache (81.3 and 87.5%); dizziness/vertigo (79.3 and 78.6%); seizures (67.3 and 70.0%); psycho motor deficiency (72.0 and 67.7%) and endocrine disorders, 75.0% for each sex. The highest proportion of normal CCT (65.3%) was requested by medical 'convenios'. The cost with normal CCT reached US$ 565,225 and with the abnormal ones, US$ 381,247. Cost with normal CCT were 2,2 higher for medical convenios as compared to those of the National Institute of Security requests and 2.8 more than those of private medicine. (author)

  14. Findings of bedside swallowing assessment and brain computerized tomography in patients with chronic cerebral infarction, and their outcome

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Toshihiko; Koshibu, Junko; Kikawada, Masayuki; Yoneda, Youichi; Uno, Masanobu; Takasaki, Masaru [Tokyo Medical Coll. (Japan); Imamura, Toshiharu

    2001-09-01

    To estimate the usefulness of the bedside swallowing assessment proposed by Smithard et al and neuroimaging findings characteristic for dysphagia, we studied the outcome of 102 patients with chronic cerebral infarction after assessment of swallowing by this test with brain computerized tomography (CT). All patients had a variety of motor disturbance and were admitted on a long-term medicare basis. They were divided into two groups according to the findings: the positive group (n=33), who showed any of the listed types of difficulty in swallowing water, and the negative group (n=69). Followed up to 2.2 years, their outcomes were studied. CT findings were studied on type of infarction, number and laterality of infarction, grade of periventricular lucency (PVL), presence of ventricular dilatation (VD), and severity of cortical atrophy (CA). The mean age was 76.4 years at registration and 61 were men. The frequency of severe dementia and disturbed ADL were significantly higher in the positive group. Eighteen patients died during the observation period and 15 of those were in the positive group, indicating higher, annual death rate (29.9% vs 2.2% in the negative group). All of the 15 patients in the positive group died of pneumonia. CT findings showed high incidence of multiple infarction, bilateral hemispheric lesion, severe PVL, VD, and severe CA in the positive group. These findings indicated that this evaluation method was useful in screening swallow function for patients with cerebral infarction in the chronic phase. Furthermore, CT findings suggested that severe white matter lesion, VD, and severe CA as well as multiple infarction seen in bilateral hemisphere was related to dysphagia, probably due to multiple factors involving pyramidal- and extrapyramidal-tracts with higher brain function. (author)

  15. Findings of bedside swallowing assessment and brain computerized tomography in patients with chronic cerebral infarction, and their outcome

    International Nuclear Information System (INIS)

    Iwamoto, Toshihiko; Koshibu, Junko; Kikawada, Masayuki; Yoneda, Youichi; Uno, Masanobu; Takasaki, Masaru; Imamura, Toshiharu

    2001-01-01

    To estimate the usefulness of the bedside swallowing assessment proposed by Smithard et al and neuroimaging findings characteristic for dysphagia, we studied the outcome of 102 patients with chronic cerebral infarction after assessment of swallowing by this test with brain computerized tomography (CT). All patients had a variety of motor disturbance and were admitted on a long-term medicare basis. They were divided into two groups according to the findings: the positive group (n=33), who showed any of the listed types of difficulty in swallowing water, and the negative group (n=69). Followed up to 2.2 years, their outcomes were studied. CT findings were studied on type of infarction, number and laterality of infarction, grade of periventricular lucency (PVL), presence of ventricular dilatation (VD), and severity of cortical atrophy (CA). The mean age was 76.4 years at registration and 61 were men. The frequency of severe dementia and disturbed ADL were significantly higher in the positive group. Eighteen patients died during the observation period and 15 of those were in the positive group, indicating higher, annual death rate (29.9% vs 2.2% in the negative group). All of the 15 patients in the positive group died of pneumonia. CT findings showed high incidence of multiple infarction, bilateral hemispheric lesion, severe PVL, VD, and severe CA in the positive group. These findings indicated that this evaluation method was useful in screening swallow function for patients with cerebral infarction in the chronic phase. Furthermore, CT findings suggested that severe white matter lesion, VD, and severe CA as well as multiple infarction seen in bilateral hemisphere was related to dysphagia, probably due to multiple factors involving pyramidal- and extrapyramidal-tracts with higher brain function. (author)

  16. Clinical diagnosis of bone metastases of cervical cancer by sup(99m)Tc scintigraphy and computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Doi, S; Okamura, S; Ueki, M; Sugimoto, O [Osaka Medical Coll., Takatsuki (Japan)

    1980-05-01

    Early diagnosis of recurrence after treatment of cervical cancer has large influence on the prognosis. Local recurrence can be easily discovered by speculum inspection and palpation and also by association with cytodiagnosis and colposcopy. However, remote metastases, especially bone metastasis, though not highly frequent, have been difficult to diagnose. Therefore, we attempted the combination of computerized tomography and bone scintigraphy using sup(99m)Tc-labeled phosphate in 79 cases treated for cervical cancer at stage I to III. As a result, bone metastases was found in 16.7% of the 79 patients. Out of these 79 cases, bone metastases was considered as positive by bone scintigraphy in 15 cases (20.0%), as false positive in 9 cases (11.4%) and as negative, in 55 cases (69.6%). In 24 cases consisting of 15 positive and 9 false-negative cases of bone scintigraphy, CT was performed; 13 cases were proved positive and 11 cases, negative. Thirteen cases, proved positive by both bone scintigraphy and CT were diagnosed to surely have bone metastases. Metastases was found most frequently in the vertebral column (42.1%), and the ribs (26.3%). It was found also in the pelvis and in the femur in some cases. In the cases confirmed in operation to have metastases into the lymphatic glands, the incidence of bone metastases was higher (22.5%) than in the cases without. Metastases were discovered in many cases within 1 year after operation. From the above results, it was found that bone scintigraphy was useful for early discovery of bone metastases after treatment of cervical cancer, and that the additional application with CT would be very valuable in raising the success rate for discovery.

  17. 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

  18. Lesions of cartilage in the femoropateliar joint, diagnosis by computerized tomography

    International Nuclear Information System (INIS)

    Reiser, M.; Anacker, H.; Karpf, P.M.; Hoerterer, H.; Paar, O.; Riel, K.A.

    1982-01-01

    The conventional arthrographic methods for demonstration of the femoro-patellar joint are not sufficiently reliable. Through the use of CT-arthrography a cross-sectional image free of superimposition and possessing a high density resolution is available thus facilitating a direct demonstration of the joint cartilage. Traumatic and degenerative lesions of the cartilage can be clearly shown by CT-arthrography. Damage of cartilage in patients with chondromalacia patellae can be differentiated in its different stages. The shape of the patella and its relation to femoral condyles can be evaluated more accurate than by conventional axial X-rays. (orig.) [de

  19. Lesions of cartilage in the femoropateliar joint, diagnosis by computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M.; Anacker, H.; Karpf, P.M.; Hoerterer, H.; Paar, O.; Riel, K.A.

    1982-01-21

    The conventional arthrographic methods for demonstration of the femoro-patellar joint are not sufficiently reliable. Through the use of CT-arthrography a cross-sectional image free of superimposition and possessing a high density resolution is available thus facilitating a direct demonstration of the joint cartilage. Traumatic and degenerative lesions of the cartilage can be clearly shown by CT-arthrography. Damage of cartilage in patients with chondromalacia patellae can be differentiated in its different stages. The shape of the patella and its relation to femoral condyles can be evaluated more accurate than by conventional axial X-rays.

  20. Computerized assessment of body image in anorexia nervosa and bulimia nervosa: comparison with standardized body image assessment tool.

    Science.gov (United States)

    Caspi, Asaf; Amiaz, Revital; Davidson, Noa; Czerniak, Efrat; Gur, Eitan; Kiryati, Nahum; Harari, Daniel; Furst, Miriam; Stein, Daniel

    2017-02-01

    Body image disturbances are a prominent feature of eating disorders (EDs). Our aim was to test and evaluate a computerized assessment of body image (CABI), to compare the body image disturbances in different ED types, and to assess the factors affecting body image. The body image of 22 individuals undergoing inpatient treatment with restricting anorexia nervosa (AN-R), 22 with binge/purge AN (AN-B/P), 20 with bulimia nervosa (BN), and 41 healthy controls was assessed using the Contour Drawing Rating Scale (CDRS), the CABI, which simulated the participants' self-image in different levels of weight changes, and the Eating Disorder Inventory-2-Body Dissatisfaction (EDI-2-BD) scale. Severity of depression and anxiety was also assessed. Significant differences were found among the three scales assessing body image, although most of their dimensions differentiated between patients with EDs and controls. Our findings support the use of the CABI in the comparison of body image disturbances in patients with EDs vs. Moreover, the use of different assessment tools allows for a better understanding of the differences in body image disturbances in different ED types.

  1. Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

    1997-01-01

    Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

  2. Application of computerized axial tomography in the field of nondestructive testing

    International Nuclear Information System (INIS)

    Reimers, P.; Heidt, H.; Stade, J.; Weise, H.P.

    1980-01-01

    So far, CAT devices have been used exclusively for medical purposes. In materials testing, higher attenuation in most test specimens requires higher photon energies. Higher photon energies, in turn, require other types of radiation sources, other types of collimators, and other types of detectors which must have sufficient efficiency for this 'harder' radiation. Another requirement on a materials testing CAT device is a lateral resolution better than 1 to 2 mm - the usual resolution of medical devices. Irregular shapes of pieces and more pronounced hardening on radiology with continuous spectra require novel correction techniques in image reconstruction. This means that a completely new CAT scanning device must be developed for materials. In view of its highly diverse applications, a modular structure would most favourable. (orig./RW) [de

  3. The diagnosis of intracranial tumors by CT (computerized tomography) from a practical point of view

    International Nuclear Information System (INIS)

    Elke, M.; Wiggli, U.; Huenig, R.

    1977-01-01

    In a historical abstract the mathematical basis of image reconstruction techniques and CT is reviewed. The enhancement of iodine contrast media is essential in CT diagnostis of space occupying intracranial lesions. Intracranial tumors usually show relatively characteristical but mostly non-specific absorption patterns. Additional clinical information is necessary for differential diagnostic evalution. The development of tables with various tumor patterns is recommended. Absorption feature of primary and secondary brain-tumors with the surrounding edema is explained. Glioblastomas as well as metastases often show a distinct cerebral edema which has been observed in 64% of our patients with metastases and distinctly localized high dense foci in 69%. 6,000 patients were investigated by CT and 1,708 examinations were performed with contrast enhancement. Side-effects are within the known reaction of other intravenously applicated contrast media. (orig.) [de

  4. Diagnosis of intracranial tumors by CT (computerized tomography) from a practical point of view

    Energy Technology Data Exchange (ETDEWEB)

    Elke, M; Wiggli, U; Huenig, R [Basel Univ. (Switzerland). Inst. fuer Medizinische Radiologie

    1977-04-01

    In a historical abstract the mathematical basis of image reconstruction techniques and CT is reviewed. The enhancement of iodine contrast media is essential in CT diagnostis of space occupying intracranial lesions. Intracranial tumors usually show relatively characteristical but mostly non-specific absorption patterns. Additional clinical information is necessary for differential diagnostic evalution. The development of tables with various tumor patterns is recommended. Absorption feature of primary and secondary brain-tumors with the surrounding edema is explained. Glioblastomas as well as metastases often show a distinct cerebral edema which has been observed in 64% of our patients with metastases and distinctly localized high dense foci in 69%. 6,000 patients were investigated by CT and 1,708 examinations were performed with contrast enhancement. Side-effects are within the known reaction of other intravenously applicated contrast media.

  5. Anatomical Variations of Carotid Artery and Optic Nerve in Sphenoid Sinus Using Computerized Tomographic Imaging

    Directory of Open Access Journals (Sweden)

    Nikakhlagh

    2014-12-01

    Full Text Available Background Sphenoid sinus is surrounded by many vital vascular and nervous structures. In more than 20% of patients with chronic sinusitis, involvement of sphenoid sinus has been observed. Besides, sphenoid sinus is an appropriate route to access anterior and middle cranial fossa in surgery. Therefore, it is important to have an adequate knowledge about the contents of sphenoid sinus and its proximity for nasal endoscopy, sinus surgeries and neurosurgeries. Objectives The aim of this study was to study sphenoid sinus proximity with carotid artery and the optic nerve using computerized tomographic imaging. Materials and Methods In this prospective study, computerized tomographic images of sphenoid sinus of patients referred to Imam Khomeini and Apadana hospitals were studied. The images were studied regarding any bulging, as well as not having a bone covering in sphenoid sinus regarding internal carotid artery and optic nerve. Furthermore, unilateralness or bilateralness of their relationships was studied. Results Among 468 coronal and axial CT scan images of sphenoid sinus, 365 (78% showed post-sellar pneumatization and 103 (22% pre-sellar pneumatization. Regarding existence of internal septa, 346 (74% cases showed multiple septation, and the remaining images were reported to have a single septum. According to the reports of CT scan images, the existence of bulging as a result of internal carotid artery and uncovered artery were 4.22% and 5.8% in the right sinus, 4.9% and 5.4% in the left sinus, and 4.34% and 4.6% in both sinuses, respectively. According to the reports of CT scan images, existence of bulging as a result of optic nerve and uncovered nerve were 5.7% and 4.3% in the right sinus, 6% and 5.4% in the left sinus, and 12% and 3.2% in both sinuses, respectively. Conclusions Due to variability of sphenoid sinus pneumatization and the separator blade of the two sinus cavities, careful attention is required during sinus surgery to avoid

  6. A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vivek Gaurav

    2013-01-01

    Full Text Available Background: Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. Aim: The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT in assessing the same. Settings and Design: A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. Statistical analysis used: The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. Results and Conclusion: The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

  7. Fuzzy modeling of electrical impedance tomography images of the lungs

    International Nuclear Information System (INIS)

    Tanaka, Harki; Ortega, Neli Regina Siqueira; Galizia, Mauricio Stanzione; Borges, Joao Batista; Amato, Marcelo Britto Passos

    2008-01-01

    Objectives: Aiming to improve the anatomical resolution of electrical impedance tomography images, we developed a fuzzy model based on electrical impedance tomography's high temporal resolution and on the functional pulmonary signals of perfusion and ventilation. Introduction: Electrical impedance tomography images carry information about both ventilation and perfusion. However, these images are difficult to interpret because of insufficient anatomical resolution, such that it becomes almost impossible to distinguish the heart from the lungs. Methods: Electrical impedance tomography data from an experimental animal model were collected during normal ventilation and apnoea while an injection of hypertonic saline was administered. The fuzzy model was elaborated in three parts: a modeling of the heart, the pulmonary ventilation map and the pulmonary perfusion map. Image segmentation was performed using a threshold method, and a ventilation/perfusion map was generated. Results: Electrical impedance tomography images treated by the fuzzy model were compared with the hypertonic saline injection method and computed tomography scan images, presenting good results. The average accuracy index was 0.80 when comparing the fuzzy modeled lung maps and the computed tomography scan lung mask. The average ROC curve area comparing a saline injection image and a fuzzy modeled pulmonary perfusion image was 0.77. Discussion: The innovative aspects of our work are the use of temporal information for the delineation of the heart structure and the use of two pulmonary functions for lung structure delineation. However, robustness of the method should be tested for the imaging of abnormal lung conditions. Conclusions: These results showed the adequacy of the fuzzy approach in treating the anatomical resolution uncertainties in electrical impedance tomography images. (author)

  8. Monte Carlo simulation of gamma ray tomography for image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Karlos A.N.; Moura, Alex; Dantas, Carlos; Melo, Silvio; Lima, Emerson, E-mail: karlosguedes@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Meric, Ilker [University of Bergen (Norway)

    2015-07-01

    The Monte Carlo simulations of known density and shape object was validate with Gamma Ray Tomography in static experiments. An aluminum half-moon piece placed inside a steel pipe was the MC simulation test object that was also measured by means of gamma ray transmission. Wall effect of the steel pipe due to irradiation geometry in a single pair source-detector tomography was evaluated by comparison with theoretical data. MCNPX code requires a defined geometry to each photon trajectory which practically prevents this usage for tomography reconstruction simulation. The solution was found by writing a program in Delphi language to create input files automation code. Simulations of tomography data by automated MNCPX code were carried out and validated by experimental data. Working in this sequence the produced data needed a databank to be stored. Experimental setup used a Cesium-137 isotopic radioactive source (7.4 × 109 Bq), and NaI(Tl) scintillation detector of (51 × 51) × 10−3 m crystal size coupled to a multichannel analyzer. A stainless steel tubes of 0,154 m internal diameter, 0.014 m thickness wall. The results show that the MCNPX simulation code adapted to automated input file is useful for generating a matrix data M(θ,t), of a computerized gamma ray tomography for any known density and regular shape object. Experimental validation used RMSE from gamma ray paths and from attenuation coefficient data. (author)

  9. A clinical study on the detection of epileptogenic foci in epileptics using computerized tomography

    International Nuclear Information System (INIS)

    Kobayashi, Eiki

    1979-01-01

    EEG findings of partial epilepsy were classified as localized abnormality in 65%, diffuse abnormality in 21% and borderline in 14% of cases. Abnormal CT findings of partial epilepsy were observed in 37% of the patients. These findings consisted of localized abnormalities in 68% and diffuse abnormalities in 32% of cases, and these were classified into 4 groups; localized or diffuse cerebral atrophy, localized low density, localized or multiple disseminated high density (calicification) and localized enhancement with contrast medium. Abnormal CT findings were more frequent in the cases of onset under 10 years of age. The incidence of CT abnormality seemed to be higher in the cases with continuous, especially continuous localized EEG abnormality, than in the cases with the other types of EEG abnormality. In the 16 cases out of 37 with CT abnormality, that is in 43% of the cases, the location of abnormal CT findings was coincident with that of their EEG foci. And epileptogenic foci were verified in 16% of all the patients. Cerebral angiography showed various and precise vascular abnormalities in 82% of these cases. And the CT abnormal group of patients was inferred to have considerable histopathological changes in the epileptogenic foci, but the group with normal CT images did not yield such significant findings. In comparison with partial epilepsy, 100 cases of generalized epilepsy were studied, and CT abnormalities were observed only in 16% of cases. Diffuse cerebral atrophy was naturally the most frequent kind of abnormal finding, and localized abnormalities were not so frequent in generalized epilepsy. (Kanao, N.)

  10. The surgical outcome of parasagittal and falx meningioma in the era of microsurgery and computerized tomography

    International Nuclear Information System (INIS)

    Kashiwagi, Shiro; Saul, T.G.; Tew, J.M. Jr.

    1990-01-01

    We experienced the surgical treatment of supratentorial midline meningiomas including 23 parasagittal and 15 falx meningiomas since the introduction of CT and routine use of microsurgical techniques. There were 17 meningiomas in the anterior third of the superior sagittal sinus; 15 in the middle third and 6 in posterior third. There were 12 males and 26 females. The age ranged from 29 to 84 years with an average of 56.6. Thirty six cases were evaluated with CT preoperatively, and two with magnetic resonance imaging. Surgical excision was performed with microsurgical techniques. The carbon dioxide laser was used in 13 recent cases. The extent of the tumor removal was expressed according to Simpson's classification. Grade 1 removal was performed in 13 of 17 anterior third tumors; 2 of 15 middle third; and 1 of the 6 posterior third tumors. Grade 2 removal was performed in 2 of the 17 anterior third; 10 of 15 middle third; and 4 of 6 posterior third tumors. Grade 3 removal was performed in 1 anterior third; 2 middle third; and 1 posterior third tumors. Grade 4 removal was performed in 1 anterior third tumor and 1 middle third tumor. The operative mortality was 2.6% (1 out of 38). Sixteen patients (42.1%) were neurologically intact pre and postoperatively. The functional capability in 24 survivors with the follow-up period longer than 4 years (mean of 6 years) were no disability in 14 patients (58.3%), partial disability but independent in 7 (29.2%), and complete disability in 3 (12.5%). The immediate and late outcomes of present series were better than those of earlier reported series in which the majority of the cases were diagnosed with angiography and treated with conventional surgical techniques. Early accurate diagnosis with CT scan with refinements of surgical techniques, such as routine use of microsurgery, have improved surgical outcomes, but did not reduce the recurrence rate in the supratentorial midline meningiomas. (author)

  11. Analysis of progression of cervical OPLL using computerized tomography: typical sign of maturation of OPLL mass.

    Science.gov (United States)

    Choi, Byung-Wan; Baek, Dong-Hoon; Sheffler, Lindsey C; Chang, Han

    2015-07-17

    OBJECT The progression of cervical ossification of the posterior longitudinal ligament (OPLL) can lead to increase in the size of the OPLL mass and aggravation of neurological symptoms. In the present study, the authors aimed to analyze the progression of cervical OPLL by using CT imaging, elucidate the morphology of OPLL masses, and evaluate the factors associated with the progression of cervical OPLL. METHODS Sixty patients with cervical OPLL were included. All underwent an initial CT examination and had at least 24 months' follow-up with CT. The mean duration of follow-up was 29.6 months. Fourteen patients (Group A) had CT evidence of OPLL progression, and 46 (Group B) did not show evidence of progression on CT. The 2 groups were compared with respect to the following variables: sex, age, number of involved segments, type of OPLL, and treatment methods. The CT findings, such as the connection of an OPLL mass with the vertebral body and formation of trabeculation in the mass, were evaluated. RESULTS Sex and treatment modality were not associated with OPLL progression. The mean age of the patients in Group A was significantly lower than that in Group B (p = 0.03). The mean number of involved segments was 5.3 in Group A and 3.6 in Group B (p = 0.002). Group A had a higher proportion of cases with the mixed type of OPLL, whereas Group B had a higher proportion of cases with the segmental type (p = 0.02). A connection between the vertebral body and OPLL mass and trabeculation formation were more common in Group B (p cervical OPLL is associated with younger age, involvement of multiple levels, and mixed-type morphology. OPLL masses that are contiguous with the vertebral body and have trabecular formation are useful findings for identifying masses that are less likely to progress.

  12. Imaging of osteo-odonto-keratoprosthesis by electron beam tomography

    OpenAIRE

    Fong, K C S; Ferrett, C G; Tandon, R; Paul, B; Herold, J; Liu, C S C

    2005-01-01

    Aim: To describe the experience of using electron beam tomography (EBT) in imaging of osteo-odonto-keratoprosthesis (OOKP) to identify early bone and dentine loss which may threaten the viability of the eye.

  13. 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...

  14. Tomography

    International Nuclear Information System (INIS)

    1985-01-01

    Already widely accepted in medicine, tomography can also be useful in industry. The theory behind tomography and a demonstration of the technique to inspect a motorcycle carburetor is presented. To demonstrate the potential of computer assisted tomography (CAT) to accurately locate 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

  15. A Comparison of In-Room Computerized Tomography Options for Detection of Fiducial Markers in Prostate Cancer Radiotherapy

    International Nuclear Information System (INIS)

    Owen, Rebecca; Foroudi, Farshad; Kron, Tomas; Milner, Alvin; Cox, Jennifer; Cramb, Jim; Zhu Li; Duchesne, Gillian

    2010-01-01

    Purpose: To compare volumetric in-room computed tomography (CT) and kilovoltage (kV) cone-beam CT (CBCT) to planar imaging with respect to their ability to localize fiducial markers (FMs) for radiotherapy of prostate cancer. Methods and Materials: Image guidance options from two linear accelerators were compared in terms of identifying the center of gravity (COG) of FMs from the isocenter: a Siemens Primatom, where the couch is rotated 180 degrees from the treatment isocenter to the in-room CT vs. electronic portal imaging (EPI); and a Varian OBI system, where kV CBCT, EPI, and planar kV radiographs were compared. In all, 387 image pairs (CBCT = 133; CT = 254) from 18 patients were analyzed. A clinical tolerance of 3 mm was predefined as the acceptable threshold for agreement. Results: COG location on in-room CT and EPI was in agreement 96.9%, 85.8%, and 89.0% of the time in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) directions, respectively, vs. 99.2%, 91.7%, and 93.2% for the CBCT and EPI analysis. The CBCT vs. kV radiographs were in agreement 100% (LR), 85.4% (SI), and 88.5% (AP), and EPI vs. kV radiographs were in agreement 100% (LR), 94.6% (SI), and 91.5% (AP) of the time. Conclusion: Identification of FMs on volumetric or planar images was found to be not equivalent (±3 mm) using either linear accelerator. Intrafraction prostate motion, interpretation of FM location, and spatial properties of images are contributing factors. Although in-room CT has superior image quality, the process of realigning the treatment couch to acquire a CT introduces an error, highlighting the benefits of a single isocentric system.

  16. Strut fracture and disc embolization of a Björk-Shiley mitral valve prosthesis: localization of embolized disc by computerized axial tomography.

    Science.gov (United States)

    Larrieu, A J; Puglia, E; Allen, P

    1982-08-01

    The case of a patient who survived strut fracture and embolization of a Björk-Shiley mitral prosthetic disc is presented. Prompt surgical treatment was directly responsible for survival. In addition, computerized axial tomography of the abdomen aided in localizing and retrieving the embolized disc, which was lodged at the origin of the superior mesenteric artery. A review of similar case reports from the literature supports our conclusions that the development of acute heart failure and absent or muffled prosthetic heart sounds in a patient with a Björk-Shiley prosthetic heart valve inserted prior to 1978 should raise the possibility of valve dysfunction and lead to early reoperation.

  17. Post transplant urinary tract infection in Autosomal dominant polycystic kidney disease a perpetual diagnostic dilema - 18-fluorodeoxyglucose - Positron emission computerized tomography - A valuable tool

    International Nuclear Information System (INIS)

    Sainaresh, VV; Jain, SH; Patel, HV; Shah, PR; Vanikar, AV; Trivedi, HL

    2011-01-01

    Urinary tract infection (UTI) is the most common infection contracted by renal allograft recipients. In patients of autosomal dominant polycystic kidney disease (ADPKD), cyst infection presents a complex diagnostic and therapeutic challenge especially in the post transplant period. Accurate diagnosis forms the cornerstone in salvaging the graft from potentially catastrophic outcome. We describe a case of xanthogranulomatous pyelonephritis (XPN) in the native kidney in a patient of post transplant ADPKD which presented as frequently relapsing UTI with graft dysfunction where in accurate diagnosis was made possible with the aid of 18-fluorodeoxyglucose (FDG) - Positron emission computerized tomography (PET/CT)

  18. Quantification of Soil Physical Properties by Using X-Ray Computerized Tomography (CT) and Standard Laboratory (STD) Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Maria Ambert [Iowa State Univ., Ames, IA (United States)

    2003-12-12

    The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, IA using two different soil management strategies. The first field study was conducted in 1999 using continuous corn crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 and on soybean crop rotation for the same soil but under chisel plow and no-till practices with wheel track and no-wheel track compaction treatments induced by a tractor-manure wagon. In addition, saturated hydraulic (K{sub s}) conductivity and the convection-dispersion (CDE) model were also applied using long-term soil management systems only during 2001. The results obtained for the 1999 field study revealed no significant differences between treatments and laboratory methods, but significant differences were found at deeper depths of the soil column for tillage treatments. The results for standard laboratory procedure versus CT method showed significant differences at deeper depths for the chisel plow treatment and at the second lower depth for no-till treatment for both laboratory methods. The macroporosity distribution experiment showed significant differences at the two lower depths between tillage practices. Bulk density and percent porosity had significant differences at the two lower depths of the soil column. The results obtained for the 2001 field study showed no significant differences between tillage practices and compaction practices for both laboratory methods, but significant differences between tillage practices with wheel track and no-wheel compaction treatments were found along the soil

  19. Imaging in hematology. Part 2: Computed tomography, magnetic resonance imaging and nuclear imaging

    International Nuclear Information System (INIS)

    Zhechev, Y.

    2003-01-01

    A dramatic increase of the role of imaging in diagnosis of blood diseases occurred with the development of computed tomography (CT) and magnetic resonance imaging (MRI). At present CT of the chest, abdomen, and pelvis is routinely employed in diagnostic and staging evaluation. The bone marrow may be imaged by one of several methods, including scintigraphy, CT and MRI. Nuclear imaging at diagnosis can clarify findings of uncertain significance on conventional staging and may be very useful in the setting of large masses to follow responses to therapy nad to evaluate the residual tumor in a large mass that has responded to treatment. Recent developments such as helical CT, single proton emission computed tomography (SPECT) and positron-emission tomography (PET) have continued to advance diagnosis and therapy

  20. Computerized tomography system

    International Nuclear Information System (INIS)

    Hellstrom, M.; Kutlik, E.; Perlin, A.

    1980-01-01

    A method for non-mechanically linking the motions of an x-ray source with an x-ray receptor during a tomographic procedure to produce a tomograph of a section of an object under examination comprising the steps of: effecting motion of said source and receptor to respective reference positions; thereafter during a tomographic procedural mode generating from at least one fixed frequency signal source first and second pulse trains, adapted to drive respective stepper motors, for effecting motion of said source and receptor, said pulse trains having a predetermined mathematical relationship dependent upon the desired fulcrum height of the tomographic section to be produced; and applying said first and second pulse trains to the respective stepper motors for a predetermined number of pulse counts to effect motion with respect to said respective reference positions and effecting a tomographic sweep thereby

  1. Computerized tomography in endocrinology

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, B.; Schmiedl, U.; Huebener, K.H.

    1987-01-05

    The role of CT in the evaluation of endocrinologic disorders is discussed and typical CT-findings in disease of the hypophysis, the thyroid, the parathyroid, the thymus and the pancreas are shown. Special interest is laid on adrenal disorders. This survey informs the clinician about the diagnostic value of CT in endocrinology.

  2. Computerized tomography in endocrinology

    International Nuclear Information System (INIS)

    Kurtz, B.; Schmiedl, U.; Huebener, K.H.

    1987-01-01

    The role of CT in the evaluation of endocrinologic disorders is discussed and typical CT-findings in disease of the hypophysis, the thyroid, the parathyroid, the thymus and the pancreas are shown. Special interest is laid on adrenal disorders. This survey informs the clinician about the diagnostic value of CT in endocrinology. (orig.) [de

  3. Transformations and algorithms in a computerized brain atlas

    International Nuclear Information System (INIS)

    Thurfjell, L.; Bohm, C.; Eriksson, L.; Karolinska Institute/Hospital, Stockholm

    1993-01-01

    The computerized brain atlas constructed at the Karolinska Hospital, Stockholm, Sweden, has been further developed. This atlas was designed to be employed in different fields of neuro imaging such as positron emission tomography (PET), single photon emission tomography (SPECT), computerized tomography (CT) and magnetic resonance imaging (MR). The main objectives with the atlas is to aid the interpretation of functional images by introducing anatomical information, to serve as a tool in the merging of data from different imaging modalities and to facilitate the comparisons of data from different individuals by allowing for anatomical standardization of individual data. The purpose of this paper is to describe the algorithms and transformations used in the implementation of the atlas software

  4. Whole brain imaging with Serial Two-Photon Tomography

    Directory of Open Access Journals (Sweden)

    Stephen P Amato

    2016-03-01

    Full Text Available Imaging entire mouse brains at submicron resolution has historically been a challenging undertaking and largely confined to the province of dedicated atlasing initiatives. The has limited systematic investigations into important areas of neuroscience, such as neural circuits, brain mapping and neurodegeneration. In this paper, we describe in detail Serial Two-Photon (STP tomography, a robust, reliable method for imaging entire brains with histological detail. We provide examples of how the basic methodology can be extended to other imaging modalities, such as optical coherence tomography, in order to provide unique contrast mechanisms. Furthermore we provide a survey of the research that STP tomography has enabled in the field of neuroscience, provide examples of how this technology enables quantitative whole brain studies, and discuss the current limitations of STP tomography-based approaches

  5. Wound areas by computerized planimetry of digital images: accuracy and reliability.

    Science.gov (United States)

    Mayrovitz, Harvey N; Soontupe, Lisa B

    2009-05-01

    Tracking wound size is an essential part of treatment. Because a wound's initial size may affect apparent healing rates, its surface area (S) and its surface area-to-perimeter (S/P) ratio are useful to document healing. Assessments of these parameters can be made by computerized planimetry of digital images using suitable software. Because different caregivers often evaluate wounds and because measurement time is important, the objective of this study was to determine accuracy, repeatability, and measurement time of S and S/P from measurements of images recorded by digital photography. Six wound images of various complexities with known areas were measured in triplicate by 20 senior nursing students during 2 sessions 1 week apart. Images included an ellipse, 2 traced venous ulcers, and photographs of a pressure, diabetic plantar, and venous ulcer. Area error was determined as the percentage difference between known and planimetry measured areas. Reliability was assessed from test-retest coefficient of variations (CV%) from which the smallest meaningful percentage change (SMPC) was determined. Area errors (mean +/- SD) ranged from -2.95% +/- 7.01% to +2.32% +/- 6.04%. For well-defined image margins, area and S/P SMPC values were all less than 3.2%. For borders that were not as well defined, SMPCs were larger, ranging between 6.2% and 10.8%. Wound measurement time decreased from 93.4 +/- 35.1 seconds at session 1 to 67.7 +/- 24.4 at session 2 (P reliable estimates of wound area and S/P ratios.

  6. Multi-Detector Computed Tomography Imaging Techniques in Arterial Injuries

    Directory of Open Access Journals (Sweden)

    Cameron Adler

    2018-04-01

    Full Text Available Cross-sectional imaging has become a critical aspect in the evaluation of arterial injuries. In particular, angiography using computed tomography (CT is the imaging of choice. A variety of techniques and options are available when evaluating for arterial injuries. Techniques involve contrast bolus, various phases of contrast enhancement, multiplanar reconstruction, volume rendering, and maximum intensity projection. After the images are rendered, a variety of features may be seen that diagnose the injury. This article provides a general overview of the techniques, important findings, and pitfalls in cross sectional imaging of arterial imaging, particularly in relation to computed tomography. In addition, the future directions of computed tomography, including a few techniques in the process of development, is also discussed.

  7. The Pattern of Significant Lesions Found in Computerized ...

    African Journals Online (AJOL)

    Introduction: Seizures are common reasons for neurologic consultations and investigations. In the absence of magnetic resonance imaging, computerized tomography scanning of the brain is a reliable and cheaper alternative. Little is known about the pattern of brain lesions in patients with recurrent seizures in Nigeria.

  8. The Pattern of Significant Lesions Found in Computerized ...

    African Journals Online (AJOL)

    2017-12-05

    Dec 5, 2017 ... Introduction: Seizures are common reasons for neurologic consultations and investigations. In the absence of magnetic resonance imaging, computerized tomography scanning of the brain is a reliable and cheaper alternative. Little is known about the pattern of brain lesions in patients with recurrent ...

  9. Non-destructive analysis and detection of internal characteristics of spruce logs through X computerized tomography; Detection et analyse non destructive de caracteristiques internes de billons d'epicea commun (PICEA ABIES (L.) KARST) par tomographie a rayons X

    Energy Technology Data Exchange (ETDEWEB)

    Longuetaud, F

    2005-10-15

    Computerized tomography allows a direct access to internal features of scanned logs on the basis of density and moisture content variations. The objective of this work is to assess the feasibility of an automatic detection of internal characteristics with the final aim of conducting scientific analyses. The database is constituted by CT images of 24 spruces obtained with a medical CT scanner. Studied trees are representative of several social status and are coming from four stands located in North-Eastern France, themselves are representative of several age, density and fertility classes. The automatic processing developed are the following. First, pith detection in logs dealing with the problem of knot presence and ring eccentricity. The accuracy of the localisation was less than one mm. Secondly, the detection of the sapwood/heart-wood limit in logs dealing with the problem of knot presence (main source of difficulty). The error on the diameter was 1.8 mm which corresponds to a relative error of 1.3 per cent. Thirdly, the detection of the whorls location and comparison with an optical method. Fourthly the detection of individualized knots. This process allows to count knots and to locate them in a log (longitudinal position and azimuth); however, the validation of the method and extraction of branch diameter and inclination are still to be developed. An application of this work was a variability analysis of the sapwood content in the trunk: at the within-tree level, the sapwood width was found to be constant under the living crown; at the between-tree level, a strong correlation was found with the amount of living branches. A great number of analyses are possible from our work results, among others: architectural analysis with the pith tracking and the apex death occurrence; analysis of radial variations of the heart-wood shape; analysis of the knot distribution in logs. (author)

  10. Non-destructive analysis and detection of internal characteristics of spruce logs through X computerized tomography; Detection et analyse non destructive de caracteristiques internes de billons d'epicea commun (PICEA ABIES (L.) KARST) par tomographie a rayons X

    Energy Technology Data Exchange (ETDEWEB)

    Longuetaud, F

    2005-10-15

    Computerized tomography allows a direct access to internal features of scanned logs on the basis of density and moisture content variations. The objective of this work is to assess the feasibility of an automatic detection of internal characteristics with the final aim of conducting scientific analyses. The database is constituted by CT images of 24 spruces obtained with a medical CT scanner. Studied trees are representative of several social status and are coming from four stands located in North-Eastern France, themselves are representative of several age, density and fertility classes. The automatic processing developed are the following. First, pith detection in logs dealing with the problem of knot presence and ring eccentricity. The accuracy of the localisation was less than one mm. Secondly, the detection of the sapwood/heart-wood limit in logs dealing with the problem of knot presence (main source of difficulty). The error on the diameter was 1.8 mm which corresponds to a relative error of 1.3 per cent. Thirdly, the detection of the whorls location and comparison with an optical method. Fourthly the detection of individualized knots. This process allows to count knots and to locate them in a log (longitudinal position and azimuth); however, the validation of the method and extraction of branch diameter and inclination are still to be developed. An application of this work was a variability analysis of the sapwood content in the trunk: at the within-tree level, the sapwood width was found to be constant under the living crown; at the between-tree level, a strong correlation was found with the amount of living branches. A great number of analyses are possible from our work results, among others: architectural analysis with the pith tracking and the apex death occurrence; analysis of radial variations of the heart-wood shape; analysis of the knot distribution in logs. (author)

  11. Computerized follow-up of discrepancies in image interpretation between emergency and radiology departments.

    Science.gov (United States)

    Siegel, E; Groleau, G; Reiner, B; Stair, T

    1998-08-01

    Radiographs are ordered and interpreted for immediate clinical decisions 24 hours a day by emergency physicians (EP's). The Joint Commission for Accreditation of Health Care Organizations requires that all these images be reviewed by radiologists and that there be some mechanism for quality improvement (QI) for discrepant readings. There must be a log of discrepancies and documentation of follow up activities, but this alone does not guarantee effective Q.I. Radiologists reviewing images from the previous day and night often must guess at the preliminary interpretation of the EP and whether follow up action is necessary. EP's may remain ignorant of the final reading and falsely assume the initial diagnosis and treatment were correct. Some hospitals use a paper system in which the EP writes a preliminary interpretation on the requisition slip, which will be available when the radiologist dictates the final reading. Some hospitals use a classification of discrepancies based on clinical import and urgency, and communicated to the EP on duty at the time of the official reading, but may not communicate discrepancies to the EP's who initial read the images. Our computerized radiology department and picture archiving and communications system have increased technologist and radiologist productivity, and decreased retakes and lost films. There are fewer face-to-face consultants of radiologists and clinicians, but more communication by telephone and electronic annotation of PACS images. We have integrated the QI process for emergency department (ED) images into the PACS, and gained advantages over the traditional discrepancy log. Requisitions including clinical indications are entered into the Hospital Information System and then appear on the PACS along with images on readings. The initial impression, time of review, and the initials of the EP are available to the radiologist dictating the official report. The radiologist decides if there is a discrepancy, and whether it

  12. Bayesian image reconstruction for improving detection performance of muon tomography.

    Science.gov (United States)

    Wang, Guobao; Schultz, Larry J; Qi, Jinyi

    2009-05-01

    Muon tomography is a novel technology that is being developed for detecting high-Z materials in vehicles or cargo containers. Maximum likelihood methods have been developed for reconstructing the scattering density image from muon measurements. However, the instability of maximum likelihood estimation often results in noisy images and low detectability of high-Z targets. In this paper, we propose using regularization to improve the image quality of muon tomography. We formulate the muon reconstruction problem in a Bayesian framework by introducing a prior distribution on scattering density images. An iterative shrinkage algorithm is derived to maximize the log posterior distribution. At each iteration, the algorithm obtains the maximum a posteriori update by shrinking an unregularized maximum likelihood update. Inverse quadratic shrinkage functions are derived for generalized Laplacian priors and inverse cubic shrinkage functions are derived for generalized Gaussian priors. Receiver operating characteristic studies using simulated data demonstrate that the Bayesian reconstruction can greatly improve the detection performance of muon tomography.

  13. Analysis of the of bones through 3D computerized tomography; Analise de estrutura ossea atraves de microtomografia computadorizada 3D

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Oliveira, L.F. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica; Alves, J.M. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2009-03-15

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-{mu}TC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-{mu}TC is a powerful technique that can be used to analyze bone microstructures. (author)

  14. Discrete Tomography and Imaging of Polycrystalline Structures

    DEFF Research Database (Denmark)

    Alpers, Andreas

    High resolution transmission electron microscopy is commonly considered as the standard application for discrete tomography. While this has yet to be technically realized, new applications with a similar flavor have emerged in materials science. In our group at Ris� DTU (Denmark's National...... Laboratory for Sustainable Energy), for instance, we study polycrystalline materials via synchrotron X-ray diffraction. Several reconstruction problems arise, most of them exhibit inherently discrete aspects. In this talk I want to give a concise mathematical introduction to some of these reconstruction...... problems. Special focus is on their relationship to classical discrete tomography. Several open mathematical questions will be mentioned along the way....

  15. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    International Nuclear Information System (INIS)

    Lu, W; Wang, J; Zhang, H

    2015-01-01

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  16. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W; Wang, J; Zhang, H [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  17. Dosimetry in phantom of newborn head for computerized tomography signs with voltages of 80, 100 and 120 KV

    International Nuclear Information System (INIS)

    Oliveira, G.A.P.; Mourão, A.P.

    2017-01-01

    Computed Tomography is the radiodiagnostic method that most contributes to the dose deposition in population. Therefore, the dose reductions used in these tests are very important, especially for pediatric patients who have a life expectancy greater than the rest of the population. This study purpose to compare the doses generated from newborns (NB) with different voltages in a 64-channel multichannel CT equipment of the GE brand. One head phantom in a cylindrical shape made in PMMA were used to newborn patient dimensions. 100 mA.s of charge of the X-ray tube were standardized, alternating the voltages between 80, 100, 120 kV in the axial acquisition. The absorbed dose measurements were performed with a pencil-type ionization chamber positioned within the five apertures in the phantom. The phantom was developed with the cephalic percentile of male NB of 14 and female of 28 days, respectively. The doses obtained in the head phantom of NB were compared with the voltages of 80, 100 and 120 kV. The volumetric dose index, C VOL , generated in the 120 kV protocol was 25.10 mGy, for 100 kV of 19,06 mGy and not for 80 kV 15,81 mGy. The results allow to evaluate that for the generation of images with 120 kV, the dose was 37.0% higher when compared to the voltage of 80 kV. The study shows that the increase in tension in the tomography protocols also makes it possible to increase the dose for the NB patient. (author)

  18. Dosimetry in phantom of newborn head for computerized tomography signs with voltages of 80, 100 and 120 KV

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.A.P.; Mourão, A.P., E-mail: giovanni.paiva@pbh.gov.br, E-mail: apratabhz@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2017-07-01

    Computed Tomography is the radiodiagnostic method that most contributes to the dose deposition in population. Therefore, the dose reductions used in these tests are very important, especially for pediatric patients who have a life expectancy greater than the rest of the population. This study purpose to compare the doses generated from newborns (NB) with different voltages in a 64-channel multichannel CT equipment of the GE brand. One head phantom in a cylindrical shape made in PMMA were used to newborn patient dimensions. 100 mA.s of charge of the X-ray tube were standardized, alternating the voltages between 80, 100, 120 kV in the axial acquisition. The absorbed dose measurements were performed with a pencil-type ionization chamber positioned within the five apertures in the phantom. The phantom was developed with the cephalic percentile of male NB of 14 and female of 28 days, respectively. The doses obtained in the head phantom of NB were compared with the voltages of 80, 100 and 120 kV. The volumetric dose index, C{sub VOL}, generated in the 120 kV protocol was 25.10 mGy, for 100 kV of 19,06 mGy and not for 80 kV 15,81 mGy. The results allow to evaluate that for the generation of images with 120 kV, the dose was 37.0% higher when compared to the voltage of 80 kV. The study shows that the increase in tension in the tomography protocols also makes it possible to increase the dose for the NB patient. (author)

  19. Review: Pre- and postinterventional control of stent grafts by means of single and multislice spiral computerized tomography

    International Nuclear Information System (INIS)

    Gebauer, B.; Knollmann, F.; Steinkamp, H.; Felix, R.

    2003-01-01

    Purpose. Could contrast enhanced computed tomography replace conventional catheter angiography in the preoperative evaluation of aortic aneurysms before stentgraft implantation? Does multi slice computed tomography have advantages comparing to single slice computed tomography? Methods. We compared 15 single slice with 13 multi slice computed tomography studies and reconstructions according to their ability to replace conventional catheter angiography in the preoperative evaluation. In the postoperative follow-up 60 single slice computed tomography studies were compared to 60 multi slice studies. Results. By using appropriate reconstructions the spiral computed tomography studies could deliver all information necessary for implantation. In our study no advantage of multi slice computed tomography could be detected. In the postoperative evaluation of stengrafts our computed tomography scan protocol could detect all relevant complications in single and multi slice computed tomography. No significant advantage of multi slice computed tomography could be detected. Conclusion. Contrast enhanced computed tomography is equal to conventional catheter angiography in the pre- and postoperative evaluation of stentgrafts. No significant advantage of multi slice versus single slice could be detected. (orig.) [de

  20. Imaging Atherosclerosis with Hybrid Positron Emission Tomography/Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Kjær, Andreas

    2015-01-01

    Noninvasive imaging of atherosclerosis could potentially move patient management towards individualized triage, treatment, and followup. The newly introduced combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system could emerge as a key player in this context. Both...

  1. Three-dimensional multifunctional optical coherence tomography for skin imaging

    Science.gov (United States)

    Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki

    2016-02-01

    Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

  2. Evaluation of symphysis pubis and sacroiliac joint distances in skeletally immature patients: A computerized tomography study of 1020 individuals.

    Science.gov (United States)

    Kalenderer, Önder; Turgut, Ali; Bacaksız, Tayfun; Bilgin, Emre; Kumbaracı, Mert; Akkan, Hasan Ali

    2017-03-01

    The aim of this study was to create a reference about normal pubic symphysis and sacroiliac joint widths of children and adolescents. A total of 1020 computerized tomography axial scans of patients without pelvic injury between 2 and 18 year-old were studied. The narrowest width of pubic symphysis and bilateral sacroiliac joints were measured. The average pubic symphyseal width at 2 years old boys was 6.35 ± 1.06 mm (4.88-9.13 mm). The average of right and left sacroiliac joints' widths at 2 years old boys was 4.56 ± 0.65 mm (3.59-6.07 mm) and 4.58 ± 0.66 mm (3.44-5.74 mm), respectively. The average pubic symphyseal width of 2 years old girls was 5.85 ± 1.14 mm (4.06-8.20 mm). The average of right and left sacroiliac joints' widths at 2 years old girls was found 4.36 ± 0.56 mm (3.50-5.37 mm) and 4.42 ± 0.59 mm (3.58-5.73 mm), respectively. The average pubic symphyseal width at 18 years old boys was found 3.68 ± 1.30 mm (1.90-5.79 mm). The average of right and left sacroiliac joints' widths at 18 years old boys was found 1.97 ± 0.21 mm (1.73-2.41 mm) and 2.04 ± 0.30 mm (1.70-2.65 mm), respectively. The average pubic symphyseal width at 18 years old girls was 3.92 ± 0.52 mm (2.97-4.76 mm). The average of right and left sacroiliac joints' widths at 18 years old girls was found 2.34 ± 0.40 mm (1.58-3.34 mm) and 2.33 ± 0.37 mm (1.58-3.10 mm), respectively. Our results suggest that one should be suspicious about pelvic injury if the width of pubic symphysis is over 10 mm and width of sacroiliac joint is over 8 mm especially in patients younger than 10 years-old. Level III Diagnostic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  3. Optical computed tomography for imaging the breast: first look

    Science.gov (United States)

    Grable, Richard J.; Ponder, Steven L.; Gkanatsios, Nikolaos A.; Dieckmann, William; Olivier, Patrick F.; Wake, Robert H.; Zeng, Yueping

    2000-07-01

    The purpose of the study is to compare computed tomography optical imaging with traditional breast imaging techniques. Images produced by computed tomography laser mammography (CTLMTM) scanner are compared with images obtained from mammography, and in some cases ultrasound and/or magnetic resonance imaging (MRI). During the CTLM procedure, a near infrared laser irradiates the breast and an array of photodiodes detectors records light scattered through the breast tissue. The laser and detectors rotate synchronously around the breast to acquire a series of slice data along the coronal place. The procedure is performed without any breast compression or optical matching fluid. Cross-sectional slices of the breast are produced using a reconstruction algorithm. Reconstruction based on the diffusion theory is used to produce cross-sectional slices of the breast. Multiple slice images are combined to produce a three dimensional volumetric array of the imaged breast. This array is used to derive axial and sagittal images of the breast corresponding to cranio-caudal and medio-lateral images used in mammography. Over 200 women and 3 men have been scanned in clinical trials. The most obvious features seen in images produced by the optical tomography scanner are vascularization and significant lesions. Breast features caused by fibrocystic changes and cysts are less obvious. Breast density does not appear to be a significant factor in the quality of the image. We see correlation of the optical image structure with that seen with traditional breast imaging techniques. Further testing is being conducted to explore the sensitivity and specificity of optical tomography of the breast.

  4. A Computerized Tablet with Visual Feedback of Hand Position for Functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mahta eKarimpoor

    2015-03-01

    Full Text Available Neuropsychological tests - behavioral tasks that very commonly involve handwriting and drawing - are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP, a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important.

  5. A computerized tablet with visual feedback of hand position for functional magnetic resonance imaging

    Science.gov (United States)

    Karimpoor, Mahta; Tam, Fred; Strother, Stephen C.; Fischer, Corinne E.; Schweizer, Tom A.; Graham, Simon J.

    2015-01-01

    Neuropsychological tests behavioral tasks that very commonly involve handwriting and drawing are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI) may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP), a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important. PMID:25859201

  6. Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography

    DEFF Research Database (Denmark)

    Lauritzen, M; Henriksen, L; Lassen, N A

    1981-01-01

    Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1...... motor area on both sides by 34 +/- 15% (p less than 0.025)....

  7. Simulated annealing image reconstruction for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sundermann, E; Lemahieu, I; Desmedt, P [Department of Electronics and Information Systems, University of Ghent, St. Pietersnieuwstraat 41, B-9000 Ghent, Belgium (Belgium)

    1994-12-31

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors). 11 refs., 2 figs.

  8. Simulated annealing image reconstruction for positron emission tomography

    International Nuclear Information System (INIS)

    Sundermann, E.; Lemahieu, I.; Desmedt, P.

    1994-01-01

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors)

  9. Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures

    Science.gov (United States)

    Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon

    2017-02-01

    We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

  10. Tomography

    International Nuclear Information System (INIS)

    Barrett, H.H.; Gordon, S.; Swindell, W.

    1980-01-01

    Apparatus is described for generating a two-dimensional back-projected image of a slice of an object in tomography. The apparatus uses optical techniques to perform the functions of filtering and back projection. Central to the technique is a cylindrical drum which rotates at a fast rate and whose rotational axis tilts at a slower rate. The novel method overcomes the problem of image blurring due to motion which occurs in many tomographic techniques. It also has the advantages of being less expensive and simpler compared to tomography using digital processing techniques which require fast computers. (UK)

  11. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    International Nuclear Information System (INIS)

    Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-01-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

  12. Optical coherence tomography for imaging of skin and skin diseases

    DEFF Research Database (Denmark)

    Mogensen, Mette; Thrane, Lars; Jørgensen, Thomas Martini

    2009-01-01

    Optical coherence tomography (OCT) is an emerging imaging technology based on light reflection. It provides real-time images with up to 2-mm penetration into the skin and a resolution of approximately 10 μm. It is routinely used in ophthalmology. The normal skin and its appendages have been studi...... technical solutions are being pursued to further improve the quality of the images and the data provided, and OCT is being integrated in multimodal imaging devices that would potentially be able to provide a quantum leap to the imaging of skin in vivo....

  13. Positron emission tomography with Positome, 2

    International Nuclear Information System (INIS)

    Nukui, Hideaki; Yamamoto, Y.L.; Thompson, C.J.; Feindel, W.

    1979-01-01

    Positron emission tomography with Positome II using 68 Ga-EDTA was performed in cases with brain tumor and cerebral arteriovenous malformation. A significant focal uptake in static study and hemodynamic changes in dynamic study were noted in all cases except one case with intracranial lipoma. Comparing this method with sup(99m) Tc-pertechnetate cerebral image study and computerized axial tomography, the diagnostic rate for detecting brain tumor was almost equal in all of these three methods. However, detecting and localizing was easier and clearer in static positron emission tomography with 68 Ga-EDTA than in sup(99m) Tc-pertechnetate cerebral image and computerized axial tomography without infusion of contrast medium. Furthermore, static positron emission tomography with 68 Ga-EDTA was superior to computerized axial tomography without infusion of contrast medium for detecting cerebral arteriovenous malformation. Concerning dynamic positron emission tomography with 68 Ga-EDTA, semiquantitative values obtained by this method correlated well with findings of computerized axial tomography and was thought to be more precise and in detail than the findings of sup(99m) Tc-pertechnetate cerebral image study. Summation of the previous studies about dynamic positron emission tomography with 77 Kr in occlusive cerebrovascular disease is also reported. In conclusion, static positron emission tomography with 68 Ga-EDTA is a very useful diagnostic method for detecting and localizing brain tumor and cerebral arteriovenous malformation without any attendant complications. Furthermore, a good combination of static and dynamic positron emission tomography and computerized axial tomography appear to be outstandingly effective for not only detecting the lesion but also understanding the pathophysiological aspect in cases with various intracranial lesions. (author)

  14. Radionuclide imaging with coded apertures and three-dimensional image reconstruction from focal-plane tomography

    International Nuclear Information System (INIS)

    Chang, L.T.

    1976-05-01

    Two techniques for radionuclide imaging and reconstruction have been studied;; both are used for improvement of depth resolution. The first technique is called coded aperture imaging, which is a technique of tomographic imaging. The second technique is a special 3-D image reconstruction method which is introduced as an improvement to the so called focal-plane tomography

  15. Computerized detection method for asymptomatic white matter lesions in brain screening MR images using a clustering technique

    International Nuclear Information System (INIS)

    Kunieda, Takuya; Uchiyama, Yoshikazu; Hara, Takeshi

    2008-01-01

    Asymptomatic white matter lesions are frequently identified by the screening system known as Brain Dock, which is intended for the detection of asymptomatic brain diseases. The detection of asymptomatic white matter lesions is important because their presence is associated with an increased risk of stroke. Therefore, we have developed a computerized method for the detection of asymptomatic white matter lesions in order to assist radiologists in image interpretation as a ''second opinion''. Our database consisted of T 1 - and T 2 -weighted images obtained from 73 patients. The locations of the white matter lesions were determined by an experienced neuroradiologist. In order to restrict the area to be searched for white matter lesions, we first segmented the cerebral region in T 1 -weighted images by applying thresholding and region-growing techniques. To identify the initial candidate lesions, k-means clustering with pixel values in T 1 - and T 2 -weighted images was applied to the segmented cerebral region. To eliminate false positives (FPs), we determined the features, such as location, size, and circularity, of each of the initial candidate lesions. Finally, a rule-based scheme and a quadratic discriminant analysis with these features were employed to distinguish between white matter lesions and FPs. The results showed that the sensitivity for the detection of white matter lesions was 93.2%, with 4.3 FPs per image, suggesting that our computerized method may be useful for the detection of asymptomatic white matter lesions in T 1 - and T 2 -weighted images. (author)

  16. Positron emission tomography and optical tissue imaging

    Science.gov (United States)

    Falen, Steven W [Carmichael, CA; Hoefer, Richard A [Newport News, VA; Majewski, Stanislaw [Yorktown, VA; McKisson, John [Hampton, VA; Kross, Brian [Yorktown, VA; Proffitt, James [Newport News, VA; Stolin, Alexander [Newport News, VA; Weisenberger, Andrew G [Yorktown, VA

    2012-05-22

    A mobile compact imaging system that combines both PET imaging and optical imaging into a single system which can be located in the operating room (OR) and provides faster feedback to determine if a tumor has been fully resected and if there are adequate surgical margins. While final confirmation is obtained from the pathology lab, such a device can reduce the total time necessary for the procedure and the number of iterations required to achieve satisfactory resection of a tumor with good margins.

  17. Computerized nipple identification for multiple image analysis in computer-aided diagnosis

    International Nuclear Information System (INIS)

    Zhou Chuan; Chan Heangping; Paramagul, Chintana; Roubidoux, Marilyn A.; Sahiner, Berkman; Hadjiiski, Labomir M.; Petrick, Nicholas

    2004-01-01

    Correlation of information from multiple-view mammograms (e.g., MLO and CC views, bilateral views, or current and prior mammograms) can improve the performance of breast cancer diagnosis by radiologists or by computer. The nipple is a reliable and stable landmark on mammograms for the registration of multiple mammograms. However, accurate identification of nipple location on mammograms is challenging because of the variations in image quality and in the nipple projections, resulting in some nipples being nearly invisible on the mammograms. In this study, we developed a computerized method to automatically identify the nipple location on digitized mammograms. First, the breast boundary was obtained using a gradient-based boundary tracking algorithm, and then the gray level profiles along the inside and outside of the boundary were identified. A geometric convergence analysis was used to limit the nipple search to a region of the breast boundary. A two-stage nipple detection method was developed to identify the nipple location using the gray level information around the nipple, the geometric characteristics of nipple shapes, and the texture features of glandular tissue or ducts which converge toward the nipple. At the first stage, a rule-based method was designed to identify the nipple location by detecting significant changes of intensity along the gray level profiles inside and outside the breast boundary and the changes in the boundary direction. At the second stage, a texture orientation-field analysis was developed to estimate the nipple location based on the convergence of the texture pattern of glandular tissue or ducts towards the nipple. The nipple location was finally determined from the detected nipple candidates by a rule-based confidence analysis. In this study, 377 and 367 randomly selected digitized mammograms were used for training and testing the nipple detection algorithm, respectively. Two experienced radiologists identified the nipple locations

  18. Examinations with computerized cranial axial tomography carried out on patients with epileptic seizures, taking into consideration the EEG and the clinical picture

    International Nuclear Information System (INIS)

    Geiser, R.

    1982-01-01

    204 patients suffering from epileptic seizures were examined with the help of computerized cranial X-ray tomography; the results were compared with anamnestic, clinical, and EEC-findings. In good agreement with results published in literature, in 54% of the patients pathologic CT's such as tumours, attack scars, changes in ventricles and arachnoid spaces etc. were found. A pathological CT is very likely to appear in male patients who are 30 or even 50 years of age, having partial attacks with elementary symptoms, focal diagnosis in the EEG and a neurological unilateral finding. Especially noteworthy is the tumour detecting rate achieved by CT and the fact that in nearly 5% of the cases CT detected a cerebral lesion which has not been suspected, neither clinically nor in the EEG (4 tumours). This shows clearly that CT represents a heighly valuable diagnostic help, especially for patients with epileptic seizures. (orig./MG) [de

  19. Thirteen-Year Evaluation of Highly Cross-Linked Polyethylene Articulating With Either 28-mm or 36-mm Femoral Heads Using Radiostereometric Analysis and Computerized Tomography

    DEFF Research Database (Denmark)

    Nebergall, Audrey K; Greene, Meridith E; Rubash, Harry E

    2016-01-01

    BACKGROUND: The objective of this 13-year prospective evaluation of highly cross-linked ultra high molecular weight polyethylene (HXLPE) was to (1) assess the long-term wear of HXLPE articulating with 2 femoral head sizes using radiostereometric analysis (RSA) and to (2) determine if osteolysis...... is a concern with this material through the use of plain radiographs and computerized tomography (CT). METHODS: All patients received a Longevity HXLPE liner with tantalum beads and either a 28-mm or 36-mm femoral head. Twelve patients (6 in each head size group) agreed to return for 13-year RSA, plain...... scan revealed areas of remodeling of this graft. One patient's 13-year plain radiographs showed evidence of cup loosening and linear radiolucencies in zones 2 and 3. CONCLUSION: There was no evidence of significant wear over time using RSA. The CT scans did not show evidence of osteolysis due to wear...

  20. Image quality and dose in computed tomography

    International Nuclear Information System (INIS)

    Jurik, A.G.; Jessen, K.A.; Hansen, J.

    1997-01-01

    Radiation exposure to the patient during CT is relatively high, and it is therefore important to optimize the dose so that it is as low as possible but still consistent with required diagnostic image quality. There is no established method for measuring diagnostic image quality; therefore, a set of image quality criteria which must be fulfilled for optimal image quality was defined for the retroperitoneal space and the mediastinum. The use of these criteria for assessment of image quality was tested based on 113 retroperitoneal and 68 mediastinal examinations performed in seven different CT units. All the criteria, except one, were found to be usable for measuring diagnostic image quality. The fulfilment of criteria was related to the radiation dose given in the different departments. By examination of the retroperitoneal space the effective dose varied between 5.1 and 20.0 mSv (milli Sievert), and there was a slight correlation between dose and high percent of ''yes'' score for the image quality criteria. For examination of the mediastinum the dose range was 4.4-26.5 mSv, and there was no significant increment of image quality at high doses. The great variation of dose at different CT units was due partly to differences regarding the examination procedure, especially the number of slices and the mAs (milli ampere second), but inherent dose variation between different scanners also played a part. (orig.). With 6 figs., 6 tabs