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Sample records for computerized tomography scan

  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. 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.)

  3. 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

  4. 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.)

  5. 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...

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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)

  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. 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)

  16. 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

  17. 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)

  18. 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)

  19. 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)

  20. 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

  1. 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

  2. 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)

  3. Regression of nodules on cranial computerized tomography (CCT) scans in 4 focal epileptic patients

    International Nuclear Information System (INIS)

    Bahk, Yong Whee; Yoon, Sei Chul; Park, Seog Hee; Huh, Choon Woong

    1983-01-01

    Epilepsy can be defined as a paroxysmal, excessive, neuronal discharge within the brain originating from either cortical or sugcortical regions. The incidence of epilepsy is increasing possibly due to the survival of persons who should have died of brain injuries or other cerebral abnormalities acquired in early life. The use of antibiotics and improvement in the medical care have saved many children who might have died of meningitis, brain abscess, encephalitis, severe head injuries, etc. CCT scan is new radiologic procedure for defining cranial and intracranial structures and also an useful procedure for evaluation and follow-up (FU) of patient with focal seizure disorder. Recently we experienced nodules which were isodense or hypodense on initial non contrasted CT (NECT) and scans became hyperdense of the enhancement in 4 cases of focal epileptic seizure. Nearly complete disappearance or regression of the epileptic foci occurred on the FU CT scans in 2 cases. Operation was performed in 2 cases. The tissue specimen obtained from the CT nodule revealed cerebral edema in one case and localized gliosis and congestion in the other. All the patients showed marked clinical improvement when the CT nodule improved. Review of literature failed to disclose any previous report on such observation

  4. 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)

  5. 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

  6. Clinical significance of bone scintigraphy and computerized tomography (CT scan) in the evaluation of renal osteodystrophy in haemodialysed and non-haemodialysed patients

    International Nuclear Information System (INIS)

    Yatsuboshi, Motohiko

    1978-01-01

    For the evaluation of renal osteodystophy in both haemodialysed and non-haemodialysed patients, bone scintigraphy and computerized tomography (CT) scan were performed. Twenty-six patients with chronic renal failure were objectives of the study. For the control study of CT scan, patients with brain tumor without renal disease were selected. Bone scan was performed approximately 3 hours after sup(99m) Tc-EHDP (ethane-1-hydroxy-1, 1-diphosphonate) administration. The numericals which were printed out from CT scanner were analyzed in the area of frontal bone. The number of positive group was 9 and that of negative was 17. Positive group in non-haemodialysed patients showed lower serum calcium level and creatinine clearance and higher serum levels of inorganic phosphate and BUN compared with those of negative group. Positive scan group showed longer duration of dialysis and higher serum levels of parathyroid hormone and alkaline phosphatase than those of negative group. Frequency of abnormal findings detected by bone scan was higher than that elicited by roentgenographic examination. CT number of positive scan group was lower than that of negative group or control group. CT number in patients with subperiosteal resorption of phalanx and abnormal findings of calvarium was lower than that of patients without such roentgenographic abnormalities. These findings indicate that bone scan is useful in detecting bone changes of secondary hyperparathyroidism in chronic renal failure. CT scan could also help to estimate the decrease of bone density of calvarium in chronic renal failure. (author)

  7. 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.)

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Quantitation of size of myocardial infarctions by computerized transmission tomography. Comparison with hot-spot and cold-spot radionuclide scans

    International Nuclear Information System (INIS)

    Gerber, K.H.; Higgins, C.B.

    1983-01-01

    The current study evaluated the ability to quantitate the volume of myocardial infarctions when they are outlined by intravenously administered contrast media in the myocardial perfusion phase and in the phase of delayed contrast enhancement of the infarct. Quantitation by contrast media was assessed from computerized transmission tomography (CTT) scans of the ex situ heart and compared with quantitation by technetium-99m (/sup 99m/Tc)pyrophosphate (/sup 99m/Tc PYP) and thallium-201 (201Tl) scans of the same ex situ hearts. True volume was defined by histochemical morphometry. CTT during the contrast perfusion phase uniformly underestimated infarct size but had a good correlation with true volume. CTT during enhancement phase correlated closely with true volume (r . 0.98) and most precisely measured true size (y . 1.06 X 0.23). The /sup 99m/Tc PYP scan overestimated infarct volume (predictive overestimation of 6 to 199%) but had a good correlation with true volume. 201Tl underestimated infarct volume but correlated well with true volume. Thus, quantitation of infarct volume from CTT scans performed during either the perfusion or infarct enhancement phase after intravenous contrast media provides a good estimate of true infarct volume. Delineation of the infarct by contrast media in the ex situ heart is more precise during the phase of delayed enhancement of the infarct

  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. 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. 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)

  16. 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.)

  17. 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)

  18. 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.

  19. 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)

  20. 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

  1. 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

  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. 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.)

  4. 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.)

  5. 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

  6. 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

  7. 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.)

  8. 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

  9. 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.

  10. 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)

  11. 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.)

  12. Computerized tomography in multiple sclerosis

    International Nuclear Information System (INIS)

    Delouvrier, J.J.; Tritschler, J.L.; Desbleds, M.T.; Cambier, J.; Nahum, H.

    1980-01-01

    The double scan CT method was applied to a homogeneous population of 50 multiple sclerosis patients and the following features were studied: well defined low-density areas, localized contrast enhancements, cerebral atrophy and white matter homogeneity. The analyses of the variance of the white matter (centrum ovale) can disclose those lesions which individually do not surpass the visibility threshold. The lesions that are localized in the white matter are mainly periventricular, most often multiple, and they do not displace the neighbouring structures. By revealing a large number of clinically silent cerebral lesions, the cerebral CT becomes a highly important diagnostic tool. The value of the CT examinations seems to be of major importance each time that the clinical diagnosis is hesitant, particularly when faced with medullary signs or an initial neurological episode. (C.F.)

  13. 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

  14. 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.

  15. Predictive value of excretory urography, ultrasonography, computerized tomography, and liver and bone scan in the staging of bilharzial bladder cancer in Saudi Arabia

    International Nuclear Information System (INIS)

    Hanash, K.A.; Bissada, N.K.; Abla, A.; Esmail, D.; Dowling, A.

    1984-01-01

    The role of ultrasonography, computed tomography (CT), and radioisotopic scanning in the staging of bilharzial bladder cancer has not been reported previously. Forty patients with invasive bladder cancer seen at the King Faisal Specialist Hospital and Research Centre between January 1978 and June 1981 underwent complete preoperative workup for staging of their tumors prior to radical cystectomy. The preoperative radiologic investigations included excretory urography (IVP), ultrasonography (US), CT of the pelvis, and liver and bone scans. The results of these investigations were compared with the operative and pathologic staging. Ninety-three percent of the patients with bilharzial cancer had evidence of ureteric obstruction on IVP compared with 22% of the nonbilharzial cancer patients. The presence of ureteric obstruction in these patients did not correlate with the stage of the disease with 83% of the patients with superficial tumors (T1 and T2) having hydroureteronephrosis. Ultrasonography and CT had an 83% accuracy in the staging of superficial tumors. Stage T3 tumors were understaged in 14% of the cases. Ultrasonography did not differentiate Stages T3 and T4 tumors while CT scan differentiated these two stages in 57% of the cases. Bone scan failed to reveal evidence of metastatic disease in any of the bilharzial cancer patients. Liver scan was suspicious for liver metastases in two patients with bilharzial cancers in whom open liver biopsy revealed only hepatic bilharziasis. Of all the radiographic studies, US or preferably CT scan seem to be of some value in the staging of bilharzial tumors localized to the bladder. Bone and liver scans are probably of no cost effective benefit

  16. 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

  17. 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.).

  18. 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

  19. 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

  20. 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)

  1. 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

  2. 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.

  3. 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)

  4. 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.

  5. 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)

  6. 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

  7. 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)

  8. 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

  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. 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.

  11. 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)

  12. 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)

  13. 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

  14. 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

  15. 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.

  16. 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)

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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)

  2. 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

  3. 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

  4. Computerized tomography(CT) in patients with head injuries, assessment of outcome based upon initial clinical findings and initial CT scans

    International Nuclear Information System (INIS)

    Espersen, J.O.; Petersen, O.F.

    1982-01-01

    In this study, which comprises 144 consecutive head injuries, the initial clinical assessment and the findings of the initial CT scan are relatd to the outcome. The mortality is related to the patient's level of consiousness and pupillary light reflex on admission. The disability rate (= number of disabled/number of survivors) was independent of the level of consiousness but closely related to pupillary light reaction. Diminished and obliterated basal cisterns were bad prognostic signs, with a mortality rate of 66% in the latter group. Both disability and mortality increase with the number of different lesion types. (Author)

  5. Juvenile nasopharyngeal angiofibroma - study of the tumor extension and vascularization through computerized tomography (CT) scan and angiography and the patient's age

    International Nuclear Information System (INIS)

    Sennes, Luiz Ubirajara

    1997-01-01

    The juvenile nasopharyngeal angiofibroma is a rare benign tumor that affects male adolescents. It is a fibro-vascular tumor with an exuberant intra tumor blood flow and irrigated by several arteries. It originates from the lateral and posterior region of the nasal cavity and, due to its characteristic multidirectional growth, widely affects the paranasal sinuses and skull base, sometimes invading the cranial fossa or the cheek. The determinant factors of its growth and vascularisation are unknown. Attempting to clarify them, 33 patients from the University of Sao Paulo Medicine were studied from 1983 to 1995, with complete history and radiological documentation (CT scan and angiography), as well as with histological confirmation of the diagnosis. In order to take only tumors with natural evolution, patients with recidivant tumor and those already submitted to any previous treatment were excluded. The parameters evaluate were: patient age and tumor extension (by classification, degree of invasion and number of compromised sites in CT scan) and vascularisation (by number and degree of participation of bilateral arteries in angiography). The se data were tabled and correlated one with each other. (author)

  6. 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)

  7. 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)

  8. 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

  9. 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.)

  10. 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.)

  11. 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)

  12. 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)

  13. 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)

  14. 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

  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. 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

  18. 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.

  19. 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

  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. 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

  2. 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

  3. 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)

  4. 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

  5. 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

  6. Cerebral toxoplasmosis in AIDS - computerized tomography evaluation

    International Nuclear Information System (INIS)

    Alves, Regina Coeli Fonseca; Narchiori, Edson

    1999-01-01

    Cerebral toxoplasmosis is a disease that affects many AIDS's patients. FOr this paper 46 patients with confirmed cases of cerebral toxoplasmosis who did a CT scan between March, 1994 and September, 1997 were examined. Single lesions were found in 28.3% of the patients. The lesions were more frequently detected in the basal ganglia and the frontal lobes. No lesion was larger than 4 cm. As regards the contrast enhancing of the lesions on a CT scan we observed that 54.5% of the lesions had a ring-like contrast enhancing, 36.4% had a nodular contrast enhancing and 6% had a heterogeneous form. After the 21st day of treatment we noticed an improvement in the aspect of the patients'lesions. The improvement of the lesions could be seen through a reduction of the edematous halo, a reduction of the lesion size and a modification in the contrast enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility with cerebral toxoplasmosis, as well as to monitor these patients during treatment. (author)

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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

  12. 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)

  13. Cerebral computerized tomography findings in AIDS patients

    International Nuclear Information System (INIS)

    Hol, P.K.; Dunlop, O.

    1997-01-01

    A cerebral CT was performed in 82 of 525 AIDS patients, with positive findings in 46 cases. These findings included cerebral atrophy in 28 cases, pathological demyelinisation in two, progressive multifocal leukoencephalopathy in one, toxoplasmoses in 11, lymphomas in seven, infarction in one and one subdural haematoma. The radiological findings are correlated to pathology and clinical symptoms. The authors point out the importance of these findings for correct interpretation of the CT scans. 11 refs., 7 figs., 2 tabs

  14. 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

  15. Use of computerized tomography in brain stroke

    Energy Technology Data Exchange (ETDEWEB)

    Landmark, K.; Aursnes, I.; Eldvik, P.; Lilleaas, F.G.

    1988-04-01

    In a retrospective study in 115 patients consecutively admitted to a ''stroke unit'', 108 were found to have been subjected to one or more cerebral CT-scans, of which ten revealed cerebral haemorrhage, two tumor cerebri and one subdural haematoma. The latter patient was successfully operated upon. The clinical diagnosis of stroke in progression was made in seven patients, whereas embolic stroke was diagnosed in 22. After haemorrhage had been excluded by CT, anticoagulant therapy (warfarin/heparin) was started for various reasons in 35 patients altogether. It is concluded that CT, if available locally, should be performed routinely during the first days following acute stroke.

  16. Use of computerized tomography in brain stroke

    International Nuclear Information System (INIS)

    Landmark, K.; Aursnes, I.; Eldvik, P.; Lilleaas, F.G.

    1988-01-01

    In a retrospective study in 115 patients consecutively admitted to a ''stroke unit'', 108 were found to have been subjected to one or more cerebral CT-scans, of which ten revealed cerebral haemorrhage, two tumor cerebri and one subdural haematoma. The latter patient was successfully operated upon. The clinical diagnosis of stroke in progression was made in seven patients, whereas embolic stroke was diagnosed in 22. After haemorrhage had been excluded by CT, anticoagulant therapy (warfarin/heparin) was started for various reasons in 35 patients altogether. It is concluded that CT, if available locally, should be performed routinely during the first days following acute stroke

  17. 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.)

  18. 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)

  19. 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

  20. Scanning Microwave Induced Acoustic Tomography

    National Research Council Canada - National Science Library

    Wang, Lihong V

    2002-01-01

    .... Specifically, our accomplishments include (1) an exact and an approximate time-domain reconstruction algorithm for thermoacoustic tomography in a spherical geometry was derived and published, (2...

  1. 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)

  2. 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

  3. 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

  4. 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

  5. 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)

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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

  11. Tomography system having axial scanning

    International Nuclear Information System (INIS)

    1976-01-01

    An improved method and apparatus has been invented for the transaxial tomographic scanning of a patient to determine mass distribution internal to the patient. A scanning system is provided having a rotatably mounted X-ray radiation source/detector assembly which orbits and scans the patient in plane of orbit. The source provides a plurality of beams of radiation in the orbital plane. Beams pass through the patient to an array of detectors which are spaced in the plane of orbit and respectively aligned with one of the beams. Radiation intensity data is collected at predetermined orientations of each beam-detector pair as the assembly orbits about the patient

  12. 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

  13. Optimization of protocol in computerized tomography scans of children's chest; Otimização de protocolo em varreduras de tomografia computadorizada de tórax infantil

    Energy Technology Data Exchange (ETDEWEB)

    Lima, L.T.A.; Roberto, W. dos S.; Mourão Filho, A.P., E-mail: luanaabrao@gmail.com, E-mail: aprata@des.cefetmg.br [Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Núcleo de Engenharia Hospitalar

    2017-07-01

    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.

  14. 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)

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. X-ray Compton line scan tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, Andreas; Lange, Axel; Jaenisch, Gerd-Ruediger [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany). Fachgruppe 8.5 - Mikro-ZfP; Hentschel, Manfred P. [Technische Univ. Berlin (Germany); Kardjilov, Nikolay; Markoetter, Henning; Hilger, Andre; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB) (Germany); Toetzke, Christian [Potsdam Univ. (Germany)

    2015-07-01

    The potentials of incoherent X-ray scattering (Compton) computed tomography (CT) are investigated. The imaging of materials of very different atomic number or density at once is generally a perpetual challenge for X-ray tomography or radiography. In a basic laboratory set-up for simultaneous perpendicular Compton scattering and direct beam attenuation tomography are conducted by single channel photon counting line scans. This results in asymmetric distortions of the projection profiles of the scattering CT data set. In a first approach, corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Comparison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT offers the potential to replace neutron tomography, which requires much more efforts.

  4. Analysis of absorbed dose in cervical spine scanning by computerized tomography using simulator objects; Análise de dose absorvida em varreduras de coluna cervical por tomografia computadorizada utlizando objetos simuladores

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, Maria Henriqueta Freire

    2015-07-01

    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)

  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. 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

  7. 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

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

    African Journals Online (AJOL)

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

  9. 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

  10. 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

  11. 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)

  12. 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)

  13. 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)

  14. 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)

  15. 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.

  16. 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

  17. 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)/

  18. 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)

  19. 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)

  20. 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.

  1. 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)

  2. Minimising medically unwarranted computed tomography scans

    International Nuclear Information System (INIS)

    Brenner, D.J.

    2012-01-01

    As computed tomography (CT) is such a superb diagnostic tool and individual CT risks are small, whenever a CT scan is clinically warranted, the CT benefit/risk balance is by far in the patient’s favour. However, if a CT scan is not clinically warranted, this balance shifts dramatically. It is likely that at least 25% of CT scans fall into this latter category, in that they could either be replaced with alternative imaging modalities or could be avoided entirely. Use of clinical decision rules for CT usage represents a powerful approach for slowing down the increase in CT usage, because they have the potential to overcome some of the major factors that result in some CT scans being undertaken when they may not be clinically helpful.

  3. 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)

  4. 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.)

  5. 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)

  6. Computerized axil tomographic scanning in tumors of the adrenal glands

    International Nuclear Information System (INIS)

    Albertotti, C.; Figueiredo, M.A.; Clemente Filho, A.S.; Secaf, F.

    1980-01-01

    Computed tomography was used for diagnosing primary or recurrent adrenal gland tumors, being positive in all nine cases and later confirmed at surgery. The tumors are adenocarcinoma (6 cases); pheochromocytoma (2); aldostenoma (1) an cyst(u). Comparison of selective arteriography, ultrasonography, scintigraphy and computed tomography has shown the later to be most accurate. (Author) [pt

  7. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil; Avaliacao dos niveis de dose media em cortes multiplos (MSAD) em tomografia computadorizada no estado de Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Thessa C., E-mail: alonso@cdtn.br [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z. [Secretaria de Vigilancia Sanitaria de Minas Gerais, Belo Horizonte, MG (Brazil); Silva, Teogenes A. da [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear. Programa de Ciencias e Tecnicas Nucleares

    2014-07-01

    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)

  8. Computed tomography scans of metastatic hepatic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Fukuda, Haruyuki; Nemoto, Yutaka [Osaka City Univ. (Japan). Faculty of Medicine

    1984-01-01

    Computed tomography scans of 114 metastatic hepatic tumors were reviewed. Central low density was found in 82 cases (71.9%) and seems to be characteristic to metastatic hepatic tumors. Dynamic CT was performed on 34 cases, and 21 (61.8%) of these had ring enhancement at the arterial phase. Most of metastatic hepatic tumors could be differentiated from hepatocellular carcinoma. However, metastatic hepatic tumors from renal cell carcinoma, renal rhabdomyosarcoma, malignant melanoma and leiomyosarcoma could not be differentiated from hepatocellular carcinoma, even with use of dynamic study.

  9. 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.

  10. 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

  11. 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.

  12. Ward nurses' knowledge of computed tomography scanning.

    Science.gov (United States)

    Majeed, M A; Nayeemuddin, M; Christie, M

    Patients benefit from and are reassured by advance information on procedures that they are to undergo. Ward nurses should have adequate knowledge of radiological investigations to ensure proper patient preparation and good interdepartmental communication to avoid delays and cancellations. This study was conducted to assess the ward nurses' knowledge of the process of computed tomography (CT) scanning. One hundred and twenty qualified nurses were asked to complete a questionnaire regarding CT scanning. The findings revealed a suboptimal level of awareness about the process. This is probably due to lack of formal teaching for nurses on the wards in regards the different radiological procedures and patient preparation. There is a strong case for better educational talks on rapidly changing radiological techniques for ward staff to ensure high-quality patient care.

  13. 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.

  14. 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

  15. 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.)

  16. 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

  17. 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

  18. 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

  19. Computerized hydraulic scanning system for quantitative non destructive examination

    International Nuclear Information System (INIS)

    Gundtoft, H.E.

    1982-01-01

    A hydraulic scanning system with five degrees of freedom is described. It is primarily designed as a universal system for fast and accurate ultrasonic inspection of materials for their internal variation in properties. The whole system is controlled by a minicomputer which also is used for evaluating and presenting of the results of the inspection. (author)

  20. 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

  1. 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.)

  2. '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

  3. 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.

  4. 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)

  5. 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

  6. 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...

  7. 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.)

  8. 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

  9. 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)

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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)

  20. 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

  1. 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.

  2. 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

  3. 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)

  4. Computerized tomography of chronic subdural hematoma extending to the tentorium

    International Nuclear Information System (INIS)

    Kondoh, Takeshi; Kanazawa, Yasuhisa; Harada, Hideaki; Tamaki, Norihiko; Matsumoto, Satoshi.

    1987-01-01

    A case of chronic subdural hematoma extending to the cerebellar tentorium is presented. The clinical feature of this case was gait disturbance with trankial ataxia. An axial CT scan showed only a diffuse high-density area in the cerebellar tentorium, but a coronal CT scan revealed a characteristic high-density lesion just on the cerebellar tentorium. The hematoma was evacuated by opening a burrhole at the convex; the gait disturbance disappeared after this operation. The value of a coronal CT scan in this case is stressed, and the mechanism of gait disturbance in a chronic subdural hematoma is discussed. (author)

  5. Computerized tomography of chronic subdural hematoma extending to the tentorium

    Energy Technology Data Exchange (ETDEWEB)

    Kondoh, Takeshi; Kanazawa, Yasuhisa; Harada, Hideaki; Tamaki, Norihiko; Matsumoto, Satoshi

    1987-06-01

    A case of chronic subdural hematoma extending to the cerebellar tentorium is presented. The clinical feature of this case was gait disturbance with trankial ataxia. An axial CT scan showed only a diffuse high-density area in the cerebellar tentorium, but a coronal CT scan revealed a characteristic high-density lesion just on the cerebellar tentorium. The hematoma was evacuated by opening a burrhole at the convex; the gait disturbance disappeared after this operation. The value of a coronal CT scan in this case is stressed, and the mechanism of gait disturbance in a chronic subdural hematoma is discussed.

  6. 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...

  7. 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

  8. 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).

  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. 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

  14. 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

  15. 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)

  16. 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.)

  17. Computerized tomography used as a routine procedure at postmortem investigations

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2009-01-01

    not found at the CT-scanning. The cause of death could be established by CT in 31%, by autopsy in 74%, and by toxicology in 22%. CT combined with data from the inquest could establish the cause of death in a majority of deaths due to severe trauma, but only in a minority of deaths caused by disease...

  18. Indications for computerized tomography in the case of headache

    International Nuclear Information System (INIS)

    Huk, W.J.

    1987-01-01

    Of the large number of patients with headache only very few suffer from an intracranial tumor. On the other hand, brain tumors may grow silently for a long period of time. Clinical analysis of patients with headache has demonstrated that a CT-scan is not indicated in cases where an adequate cause can be found and when the headache disappears together with the underlaying cause in a reasonable amount of time. A CT-scan, however, should be performed when an adequate cause is missing, when the headache recurs with increasing frequency, intensity and duration, when it is accentuated in the morning and in certain positions, and when it is associated with personality chances, dizziness and blurred vision. In chronic headache a CT-scan is indicated when a change in the character of the headache and its various qualities (location, frequency and duration of attacks, temporal coincidence etc.) can be detected. A thorough history, including the family history, of the complains together with an accurate clinical examination will deliver the criteria to avoid unnecessary CT-scanning. (orig.) [de

  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. 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.

  1. 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)

  2. 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)

  3. 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)

  4. 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.

  5. 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)

  6. 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)

  7. 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)

  8. Anti-inflamatory effect and objective evaluation of naproxen in osteoarthritis by computerized scintillation scanning

    International Nuclear Information System (INIS)

    Scheinberg, M.A.; Schainberg, H.; Diniz, R.; Nunes, A.P.; Marone, M.; Hasson, R.; Lewin, S.

    1985-01-01

    The anti-inflammatory effect of naproxen, a non-steroidal anti-inflammatory drug, in osteoarthritis was evaluated through subjective clinical and objective computerized scintigraphic scanning parameters. All patients received 1.0g daily of naproxen administered once a day in the morning during six weeks. Twenty patients were evaluated clinically and the results were favourable in 19 (95%) with complete symptoms disappearance in 9 (45%). Sixteen patients were evaluated through the computerized scintilography, and a significant reduction in the articular flow was observed in 11 patients (68.75%). Side effects were few, mild to moderate, the majority related to G.I. tract, and in none patient was necessary treatment interruption. It is concluded that naproxen is a useful agent in the treatment of osteoarthritis and the correspondent inflamation associated with the basic mechanisms of the disease. (author) [pt

  9. 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

  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. 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.

  12. 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)

  13. 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)

  14. 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)

  15. 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.

  16. Cerebral fat embolism. Case report and its computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Toshihisa; Sawada, Yusuke; Yukioka, Tetsuo; Nishide, Kazuyuki; Yoshioka, Toshiharu (Osaka Univ. (Japan). Faculty of Medicine)

    1982-11-01

    A case of cerebral fat embolism is reported. A 18-year-old patient with multiple bone fractures was in semicoma immediately after an injury. Brain CT showed no brain swelling or intracranial hematoma. Hypoxemia and alcoholemia were noted on admission, which returned to normal without improvement of consciousness level. In addition, respiratory symptoms with positive radiographic changes, tachycardia, pyrexia, sudden drop in hemoglobin level, and sudden thrombocytopenia developed. These symptoms were compatible with Gurd's criteria of systemic fat embolism. Eight days after injury, multiple low density areas appeared on CT and disappeared within the subsequent two weeks, and subdural effusion with cerebral atrophy developed. These CT findings were not considered due to cerebral trauma. Diagnosis of cerebral fat embolism was made. The subdural effusion was drained. Neurologic and pulmonary recoveries took place slowly and one month following the injury the patient became alert and exhibited fully coordinated limb movement. The CT scans of the present case well corresponded with hitherto reported pathological findings. Petechiae in the white matter must have developed on the day of injury, which could not be detected by CT examination. It is suggested that some petechial regions fused to purpuras and then gradually resolved when they were detected as multiple low density areas on CT. CT in the purpuras phase would have shown these lesions as high density areas. These lesions must have healed with formation of tiny scars and blood pigment which were demonstrated as the disappearance of multiple low density areas by CT examination. Cerebral atrophy and subsequent subdural effusion developed as a result of demyelination. The patient took the typical clinical course of cerebral fat embolism and serial CT scans served for its assessment.

  17. Multiple-energy Techniques in Industrial Computerized Tomography

    Science.gov (United States)

    Schneberk, D.; Martz, H.; Azevedo, S.

    1990-08-01

    Considerable effort is being applied to develop multiple-energy industrial CT techniques for materials characterization. Multiple-energy CT can provide reliable estimates of effective Z (Z{sub eff}), weight fraction, and rigorous calculations of absolute density, all at the spatial resolution of the scanner. Currently, a wide variety of techniques exist for CT scanners, but each has certain problems and limitations. Ultimately, the best multi-energy CT technique would combine the qualities of accuracy, reliability, and wide range of application, and would require the smallest number of additional measurements. We have developed techniques for calculating material properties of industrial objects that differ somewhat from currently used methods. In this paper, we present our methods for calculating Z{sub eff}, weight fraction, and density. We begin with the simplest case -- methods for multiple-energy CT using isotopic sources -- and proceed to multiple-energy work with x-ray machine sources. The methods discussed here are illustrated on CT scans of PBX-9502 high explosives, a lexan-aluminum phantom, and a cylinder of glass beads used in a preliminary study to determine if CT can resolve three phases: air, water, and a high-Z oil. In the CT project at LLNL, we have constructed several CT scanners of varying scanning geometries using {gamma}- and x-ray sources. In our research, we employed two of these scanners: pencil-beam CAT for CT data using isotopic sources and video-CAT equipped with an IRT micro-focal x-ray machine source.

  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. 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

  20. 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

  1. 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

  2. Clinical evaluation in hyperbaric oxygen therapy by using computerized tomography

    International Nuclear Information System (INIS)

    Matsuda, Kazumi; Kobayashi, Eiki; Mihara, Tadahiro; Asakura, Tetsuhiko; Fujimoto, Toshiro; Fujimoto, Seijiro.

    1982-01-01

    Hyperbaric Oxygen Therapy (H.O.T. for abbreviation), accompanied by usual conservative therapy, was performed on 30 patients with cerebrovascular disturbances (cerebral infarction: 20 cases; hypertensive intracerebral hemorrhage: 10 cases). The clinical signs and symptoms, clinical courses, EEG findings, and CT findings and agter the H.O.T. were then compared before. Moreover, by analyzing the changes in the CT findings (the size and Hounsfield Number of the low-density area and the effect of contrast enhancement), the authors have attempted a clinical evaluation of H.O.T. The results are as follows: 1) Infarction group: There is a tendency to have more changes in the CT findings (reduction of the low-density area, decrease in the Hounsfield Number in the low-density portion, and changes in the effect of contrast enhancement) in the earlier H.O.T. - starting group. However, there was no definite relation between the changes in the CT findings and the clinical signs and symptoms. 2) Hypertensive intracerebral hemorrhage group: there was a tendency to have a reduction in the low-density area and an improvement in the clinical signs and symptoms in cases who had an early start of H.O.T. So far as investigating hemodynamic changes is concerned, there is a limit to the ability of investigation by means of CT scan. In future, we hope to establish methods by which if will be possible to detect the hemodynamic changes more exactly with respect to the clinical evaluation of H.O.T. (author)

  3. 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)

  4. 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)

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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)

  19. 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)

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. Underdiagnosis of Vertebral Collapse on Routine Multidetector Computed Tomography Scan of the Abdomen

    International Nuclear Information System (INIS)

    Obaid, H.; Husamaldin, Z.; Bhatt, R.

    2008-01-01

    Background: Vertebral fractures are commonly associated with osteoporosis and have significant morbidity and mortality rates. Osteoporotic vertebral fractures are presently considered as a treatable and preventable condition, and early detection is vital for further management. The evaluation of vertebral compression on multidetector computed tomography (MDCT) scans of the abdomen has, to our knowledge, not been reported before. Purpose: To assess the prevalence of vertebral collapse on routine abdominal CT scans, and to evaluate the usefulness of the multiplanar reconstruction (MPR) capability of MDCT scans in accurately identifying vertebral abnormalities such as vertebral collapse, spondylolisthesis, and retrolisthesis. Material and Methods: A retrospective review of 307 MDCT scans of the abdomen was carried out at a university teaching hospital. Identifiable patient information was anonymized for data protection. All images were reviewed on a picture archiving and communications system (PACS) using sagittal MPR and bone window for the assessment of the vertebrae. Data were collected from the Computerized Radiology Information System (CRIS). Results: Vertebral collapse was seen in 42 (13.6%) of the 307 patients undergoing routine MDCT of the abdomen. Multilevel and single-level collapses were seen in 24 and 18 patients, respectively. Spondylolisthesis was identified in 5.5% (n=17), and retrolisthesis was seen in 0.6% (n=2). All patients with vertebral fracture were older than 50 years. Women were more commonly affected than men. Conclusion: A significant number of patients with vertebral collapse were diagnosed using MPR on MDCT routine scans of the abdomen

  5. Computed tomography scan based prediction of the vulnerable carotid plaque

    DEFF Research Database (Denmark)

    Diab, Hadi Mahmoud Haider; Rasmussen, Lars Melholt; Duvnjak, Stevo

    2017-01-01

    BACKGROUND: Primary to validate a commercial semi-automated computed tomography angiography (CTA) -software for vulnerable plaque detection compared to histology of carotid endarterectomy (CEA) specimens and secondary validating calcifications scores by in vivo CTA with ex vivo non......-contrast enhanced computed tomography (NCCT). METHODS: From January 2014 to October 2016 53 patients were included retrospectively, using a cross-sectional design. All patients underwent both CTA and CEA. Sixteen patients had their CEA specimen NCCT scanned. The semi-automated CTA software analyzed carotid stenosis...

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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)

  11. 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

  12. 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.

  13. 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)

  14. 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)

  15. 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)

  16. 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

  17. 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%

  18. 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

  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. 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)

  1. 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.)

  2. Fluorescent scanning x-ray tomography with synchrotron radiation

    Science.gov (United States)

    Takeda, Tohoru; Maeda, Toshikazu; Yuasa, Tetsuya; Akatsuka, Takao; Ito, Tatsuo; Kishi, Kenichi; Wu, Jin; Kazama, Masahiro; Hyodo, Kazuyuki; Itai, Yuji

    1995-02-01

    Fluorescent scanning (FS) x-ray tomography was developed to detect nonradioactive tracer materials (iodine and gadolinium) in a living object. FS x-ray tomography consists of a silicon (111) channel cut monochromator, an x-ray shutter, an x-ray slit system and a collimator for detection, a scanning table for the target organ, and an x-ray detector with pure germanium. The minimal detectable dose of iodine in this experiment was 100 ng in a volume of 2 mm3 and a linear relationship was shown between the photon counts of a fluorescent x ray and the concentration of iodine contrast material. A FS x-ray tomographic image was clearly obtained with a phantom.

  3. 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

  4. Laryngotracheobronchial papillomatosis: findings on computed tomography scans of the chest

    International Nuclear Information System (INIS)

    Marchiori, Edson; Irion, Klaus Loureiro; Zanetti, Glaucia; Missrie, Israel; Sato, Juliana

    2008-01-01

    Objectives: To present the findings of computed tomography (CT) scans of the chest in patients with laryngotracheobronchial papillomatosis. Methods: We retrospectively analyzed CT scans of eight patients, five males and three females, ranging from 5 to 18 years of age with a mean age of 10.5 years. Images were independently reviewed by two radiologists. In discrepant cases, a consensus was reached. Results: The most common CT findings were intratracheal polypoid lesions and pulmonary nodules, many of which were cavitated. Conclusions: In patients with laryngotracheobronchial papillomatosis, the most common tomographic finding was the combination of intratracheal polypoid lesions and multiple pulmonary nodules, many of which were cavitated. (author)

  5. Laryngotracheobronchial papillomatosis: findings on computed tomography scans of the chest

    Energy Technology Data Exchange (ETDEWEB)

    Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Radiologia; Araujo Neto, Cesar de [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Radiologia; Meirelles, Gustavo Souza Portes [Universidade Federal de Sao Paulo (UNIFESP-EPM), SP (Brazil); Irion, Klaus Loureiro [The Royal Liverpool University Hospital, Liverpool (United Kingdom); Zanetti, Glaucia [Faculdade de Medicina de Petropolis (FMP), RJ (Brazil); Missrie, Israel [Universidade Federal de Sao Paulo (UNIFESP-EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Sato, Juliana [Universidade Federal de Sao Paulo (UNIFESP-EPM), SP (Brazil). Dept. de Otorrinolaringologia e Cirurgia de Cabeca e Pescoco

    2008-12-15

    Objectives: To present the findings of computed tomography (CT) scans of the chest in patients with laryngotracheobronchial papillomatosis. Methods: We retrospectively analyzed CT scans of eight patients, five males and three females, ranging from 5 to 18 years of age with a mean age of 10.5 years. Images were independently reviewed by two radiologists. In discrepant cases, a consensus was reached. Results: The most common CT findings were intratracheal polypoid lesions and pulmonary nodules, many of which were cavitated. Conclusions: In patients with laryngotracheobronchial papillomatosis, the most common tomographic finding was the combination of intratracheal polypoid lesions and multiple pulmonary nodules, many of which were cavitated. (author)

  6. 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.

  7. 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)

  8. Development and Verification of Body Armor Target Geometry Created Using Computed Tomography Scans

    Science.gov (United States)

    2017-07-13

    Computed Tomography Scans by Autumn R Kulaga, Kathryn L Loftis, and Eric Murray Approved for public release; distribution is...Army Research Laboratory Development and Verification of Body Armor Target Geometry Created Using Computed Tomography Scans by Autumn R Kulaga...Development and Verification of Body Armor Target Geometry Created Using Computed Tomography Scans 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  9. Simultaneous emission and transmission scanning in positron emission tomography

    International Nuclear Information System (INIS)

    Satoh, Tomohiko; Tanaka, Kazumi; Kitamura, Keishi; Amano, Masaharu; Miura, Shuichi

    2001-01-01

    Examination by PET (positron emission tomography) scanning, following the dosage of 2-deoxy- 18 F fluoro-D-glucose (FDG), is positively utilized for the diagnosis of cancers, rather than for the purpose of studies. This is because the examination by FDG-PET (PET scanning following the dosage of FDG) ensures higher efficiency in discrimination of cancers, than conventional CT and PET. The method of whole body scanning by PET scanning following the dosage of FDG is effectively utilized not only for discrimination cancers, but also for determining the degree of malignancy of tumors and evaluating the methods of treatment of cancers. In conventional methods for examining the degree of malignancy of tumors and evaluating the methods of cancer treatment, it is necessary to correct for the gamma-ray attenuation, which requires a longer time for examination, increasing the physical and psychological pains of the patients. We have installed the simultaneous emission and transmission scanning capability into the HEADTOME-V of the Shimadzu SET-2000W Series positron emission tomographic scanning instruments, to establish an instrument that permits FDG-PET whole body scanning in actual clinical fields, with minimized physical and psychological pains of patients concerned, yet ensuring an outstandingly high examination efficiency. This report also presents some data obtained by this newly developed instrument and those obtained in practical applications. (author)

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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

  16. 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)

  17. 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)

  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. Dynamic computed tomography scanning of benign bone lesions: Preliminary results

    International Nuclear Information System (INIS)

    Levine, E.; Neff, J.R.

    1983-01-01

    The majority of benign bone lesions can be evaluated adequately using conventional radiologic techniques. However, it is not always possible to differentiate reliably between different types of benign bone lesions on the basis of plain film appearances alone. Dynamic computed tomography (CT) scanning provides a means for further characterizing such lesions by assessing their degree of vascularity. Thus, it may help in distinguishing an osteoid osteoma, which has a hypervascular nidus, from a Brodie's abscess, which is avascular. Dynamic CT scanning may also help in the differentiation between a fluid-containing simple bone cyst, which is avascular, and other solid or semi-solid benign bone lesions which slow varying degrees of vascularity. However, because of the additional irradiation involved, dynamic CT scanning should be reserved for evaluation of selected patients with benign bone lesions in whom the plain film findings are not definitive and in whom the CT findings may have a significant influence on management. (orig.)

  20. 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

  1. Osteotomy simulation and soft tissue prediction using computer tomography scans

    International Nuclear Information System (INIS)

    Teschner, M.; Girod, S.; Girod, B.

    1999-01-01

    In this paper, a system is presented that can be used to simulate osteotomies of the skull and to estimate the resulting of tissue changes. Thus, the three-dimensional, photorealistic, postoperative appearance of a patient can be assessed. The system is based on a computer tomography scan and a photorealistic laser scan of the patient's face. In order to predict the postoperative appearance of a patient the soft tissue must follow the movement of the underlying bone. In this paper, a multi-layer soft tissue model is proposed that is based on springs. It incorporates features like skin turgor, gravity and sliding bone contact. The prediction of soft tissue changes due to bone realignments is computed using a very efficient and robust optimization method. The system can handle individual patient data sets and has been tested with several clinical cases. (author)

  2. High-resolution computed tomography scan of lumbosacral spine

    International Nuclear Information System (INIS)

    Lifson, A.; Heithoff, K.B.; Burton, C.V.; Ray, C.D.

    1981-01-01

    A GE 8800 computed tomography (CT) scanner was used in over 4,000 cases of acute and chronic low back pain. Practically unlimited potentials of the study were clearly demonstrated in the diagnosis of such conditions as central and lateral spinal stenosis, overgrowth of fusions, disk herniation and free extrusion. Nonenhanced CT scanning is capable of clear visualization of soft-tissue structures: nerve roots and ganglia, epidural fat, epidural fibrous tissue, and epidural veins. CT scanning has become a primary diagnostic modality in the Low Back Clinic at our institute, replacing myelography in the majority of cases. Enhancement of the image with metrizamide was found to be of limited diagnostic value in lumbar degenerative disk disease. However, the utilization of a radiopaque material is indicated in selected circumstances. (Auth.)

  3. 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

  4. 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

  5. Studies on muon tomography for archaeological internal structures scanning

    Science.gov (United States)

    Gómez, H.; Carloganu, C.; Gibert, D.; Jacquemier, J.; Karyotakis, Y.; Marteau, J.; Niess, V.; Katsanevas, S.; Tonazzo, A.

    2016-05-01

    Muon tomography is a potential non-invasive technique for internal structure scanning. It has already interesting applications in geophysics and can be used for archaeological purposes. Muon tomography is based on the measurement of the muon flux after crossing the structure studied. Differences on the mean density of these structures imply differences on the detected muon rate for a given direction. Based on this principle, Monte Carlo simulations represent a useful tool to provide a model of the expected muon rate and angular distribution depending on the composition of the studied object, being useful to estimate the expected detected muons and to better understand the experimental results. These simulations are mainly dependent on the geometry and composition of the studied object and on the modelling of the initial muon flux at surface. In this work, the potential of muon tomography in archaeology is presented and evaluated with Monte Carlo simulations by estimating the differences on the muon rate due to the presence of internal structures and its composition. The influence of the chosen muon model at surface in terms of energy and angular distributions in the final result has been also studied.

  6. 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)

  7. 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.

  8. 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

  9. 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)

  10. 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.

  11. 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)

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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)

  17. 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.)

  18. 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.

  19. 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.)

  20. 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

  1. Computed tomography scan optimization using head phantom and radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Lorena C.; Santana, P.C.; Velasquez, Carlos E.; Mourao, Arnaldo P., E-mail: lorena.cfernandes@hotmail.com, E-mail: carlosvelcab@hotmail.com, E-mail: pridili@gmail.com, E-mail: apmourao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Centro de Imagem Molecular do INCT-Medicina Molecular (CIMol/UFMG) Belo Horizonte (Brazil); Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte (Brazil)

    2017-11-01

    The research and development in technology applied to computed tomography has been improve in the image quality, resulting in the best identification of diseases, and therefore an increase in the number of exams, among them the head exams can be highlighted. In order to promote a radioprotection and reduction on the dose of the general public some international agencies have stipulated dose limits to be followed and the implementation of the principles of ALARA in all establishments that use ionizing radiation. One of these principles is the optimization that should be treated with substantial attention, because the reduction of radiation doses can be feasible as long as it does not compromise the tomographic images; such practice is difficult to perform due to the lack of proper guidance. In optimization of the CT exams, not only the lowest dose is evaluated to obtain diagnostic image, but also should be knowledge the dose distribution throughout the scanned area. In this work were used a cylindrical head phantom of PMMA, a GE Discovery CT scan with 64 channels, and radiochromic films. The films were positioned in the phantom in their central region for the dose evaluation using the automatic control for the voltages of 80, 100 and 120 kV. The images were acquired from the scan of the phantom and the film readings were obtained through digital images. The results show an evaluation of the longitudinal kerma profiles, dose delivered, and the image noise was also observed using the central slice images. (author)

  2. Computed tomography scan optimization using head phantom and radiochromic films

    International Nuclear Information System (INIS)

    Fernandes, Lorena C.; Santana, P.C.; Velasquez, Carlos E.; Mourao, Arnaldo P.

    2017-01-01

    The research and development in technology applied to computed tomography has been improve in the image quality, resulting in the best identification of diseases, and therefore an increase in the number of exams, among them the head exams can be highlighted. In order to promote a radioprotection and reduction on the dose of the general public some international agencies have stipulated dose limits to be followed and the implementation of the principles of ALARA in all establishments that use ionizing radiation. One of these principles is the optimization that should be treated with substantial attention, because the reduction of radiation doses can be feasible as long as it does not compromise the tomographic images; such practice is difficult to perform due to the lack of proper guidance. In optimization of the CT exams, not only the lowest dose is evaluated to obtain diagnostic image, but also should be knowledge the dose distribution throughout the scanned area. In this work were used a cylindrical head phantom of PMMA, a GE Discovery CT scan with 64 channels, and radiochromic films. The films were positioned in the phantom in their central region for the dose evaluation using the automatic control for the voltages of 80, 100 and 120 kV. The images were acquired from the scan of the phantom and the film readings were obtained through digital images. The results show an evaluation of the longitudinal kerma profiles, dose delivered, and the image noise was also observed using the central slice images. (author)

  3. 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)

  4. 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.

  5. 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.)

  6. Determination of dosimetric quantities in pediatric abdominal computed tomography scans

    Energy Technology Data Exchange (ETDEWEB)

    Jornada, Tiago da Silva [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostipo por Imagem; Silva, Teogenes Augusto da, E-mail: silvata@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2014-09-15

    Objective: aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). Materials and methods: the study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. Results: No significant difference was observed in the values for weighted air kerma index (C{sub W}), but the differences were relevant in values for volumetric air kerma index (C{sub VOL}), air kerma-length product (P{sub KL,CT}) and effective dose. Conclusion: Only the CW values were lower than the DRL, suggesting that dose optimization might not be necessary. However, P{sub KL,CT} and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans. (author)

  7. Determination of dosimetric quantities in pediatric abdominal computed tomography scans*

    Science.gov (United States)

    Jornada, Tiago da Silva; da Silva, Teógenes Augusto

    2014-01-01

    Objective Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). Materials and methods The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. Results No significant difference was observed in the values for weighted air kerma index (CW), but the differences were relevant in values for volumetric air kerma index (CVOL), air kerma-length product (PKL,CT) and effective dose. Conclusion Only the CW values were lower than the DRL, suggesting that dose optimization might not be necessary. However, PKL,CT and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans. PMID:25741103

  8. 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

  9. Pathophysiological study of experimental hydrocephalus with computed tomography (CT) scan

    International Nuclear Information System (INIS)

    Murata, Takaho

    1980-01-01

    In order to investigate the pathophysiological changes during a development of hydrocephalus, the observations employing computed tomography (CT) scans and monitorings of intracranial epidural pressure (EDP) were performed in a series of kaolin-induced canine hydrocephalus. According to ''volume index'' of ventricles which was calculated from printed-out CT numbers, great individual variations were recognized in the degree of a ventricular enlargement as well as the rate of EDP. They are thought to be due to the difference in types of hydrocephalus, which have been induced by a discrepancy in the site and degree of an obstruction caused by kaolin. Periventricular lucency (PVL) of various degrees were also detected on CT scans of experimental hydrocephalus. It was always marked in the superolateral angle of frontal horn of the lateral ventricles, and differed in degree from severe to mild. PVLs were distinct in the acute stage with high EDP, and gradually became indistinct and had a tendency to disappear thereafter along with decreased EDP. They immediately disappeared after shunting operation. The pathogenesis of PVL was investigated with histological examinations, as well as by using contrast enhancement, Metrizamide ventriculography, the analysis of linear density profiles, and the measurement of regional cerebral blood flow (rCBF). Consequently, PVLs in hydrocephalus are considered to represent an acute edema or a chronic CSF retention in the periventricular white matter caused by increase of water content. In other words, they are regarded as a sign of present or preceding intraventricular hypertension on CT scan, and may become a clinical indication for shunting operation. (author)

  10. Getting a CAT Scan (For Kids)

    Medline Plus

    Full Text Available ... site Sitio para adolescentes Body Mind Sexual Health Food & ... stands for "computerized axial tomography." Translated, that means a scanner takes computer pictures of what's going on inside your body. The scan itself ...

  11. 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

  12. High-speed X-ray phase tomography with Talbot interferometer and fringe scanning method

    International Nuclear Information System (INIS)

    Kibayashi, Shunsuke; Harasse, Sébastien; Yashiro, Wataru; Momose, Atsushi

    2012-01-01

    High-speed X-ray phase tomography based on the Fourier-transform method has been demonstrated with an X-ray Talbot interferometer using white synchrotron radiation. We report the experimental results of high-speed X-ray phase tomography with fringe-scanning method instead of Fourier-transform method to improve spatial resolution without a considerable increase of scan time. To apply fringe-scanning method to high speed tomography, we tested a scan that is a synchronous combination of one-way continuous movements of the sample rotation and the grating displacement. When this scanning method was combined with X-ray phase tomography, we were able to obtain a scan time of 5 s. A comparison of the image quality derived with the conventional approach and with the proposed approach using the fringe-scanning method showed that the latter had better spatial resolution.

  13. 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.

  14. 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.

  15. [Indications and instructions to patients for a positron emission tomography-PET scan. The importance of the hybridic PET/CT-computerised tomography scan and which specialty should be responsible for its function].

    Science.gov (United States)

    Grammaticos, Philip; Datseris, Ioannis; Gerali, Sofia; Papantoniou, Vassilios; Valsamaki, Pipitsa; Boundas, Dimitrios

    2007-01-01

    Indications and instructions to patients for performing a positron emission tomography - PET scan are mentioned. Although PET camera was developed in 1970 its clinical indications were established in about 1998. The hybridic PET/CT- computerized tomography scanner appeared in 2001 and its clinical indications are still under discussion. These discussions refer to both the use of PET/CT as an acquisition correction and anatomic localization device for PET images (AC/A) and to its use as a diagnostic CT scan (dCT). Most of the patients submitted for a PET scan have already done a dCT scan. This was the case in 286 out of the first 300 patients referred to "Evangelismos" hospital in Athens for a PET scan. These two scans can be matched electronically. Extra cost, space, personnel and radiation absorption dose especially in children, are additional factors to be considered in using the PET/CT scanner. The specialty of Nuclear Medicine is now based on the PET camera, its best part and main equipment for molecular imaging. It is very much easier and faster for a Nuclear Medicine physician who routinely reports tomographic PET and SPET images, to be familiar with the CT images than for a Radiologist to get to "know how" about the PET camera and the whole Nuclear Medicine Department. Nuclear Medicine is about open radiation sources, molecular imaging, specific radio-pharmacology, radiobiology, radiation protection etc, while on the other hand in some countries, Nuclear Physicians have already spent, as part of their official training, six months in a Radiology Department whose function is considered to be at least 25% about the CT scanner. We come to the conclusion that the PET/CT scanner should be under the responsibility of the Nuclear Medicine Department and the Radiologist should act as an advisor.

  16. 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

  17. 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

  18. 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

  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. Dosimetric evaluation of cone beam computed tomography scanning protocols

    International Nuclear Information System (INIS)

    Soares, Maria Rosangela

    2015-01-01

    It was evaluated the cone beam computed tomography, CBCT scanning protocols, that was introduced in dental radiology at the end of the 1990's, and quickly became a fundamental examination for various procedures. Its main characteristic, the difference of medical CT is the beam shape. This study aimed to calculate the absorbed dose in eight tissues / organs of the head and neck, and to estimate the effective dose in 13 protocols and two techniques (stitched FOV e single FOV) of 5 equipment of different manufacturers of cone beam CT. For that purpose, a female anthropomorphic phantom was used, representing a default woman, in which were inserted thermoluminescent dosimeters at several points, representing organs / tissues with weighting values presented in the standard ICRP 103. The results were evaluated by comparing the dose according to the purpose of the tomographic image. Among the results, there is a difference up to 325% in the effective dose in relation to protocols with the same image goal. In relation to the image acquisition technique, the stitched FOV technique resulted in an effective dose of 5.3 times greater than the single FOV technique for protocols with the same image goal. In the individual contribution, the salivary glands are responsible for 31% of the effective dose in CT exams. The remaining tissues have also a significant contribution, 36%. The results drew attention to the need of estimating the effective dose in different equipment and protocols of the market, besides the knowledge of the radiation parameters and equipment manufacturing engineering to obtain the image. (author)

  1. Visual scanning training for neglect after stroke with and without a computerized lane tracking dual task

    NARCIS (Netherlands)

    van Kessel, M. E.; Geurts, A. C. H.; Brouwer, W. H.; Fasotti, L.

    2013-01-01

    Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might

  2. 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

  3. Juvenile nasopharyngeal angiofibroma - study of the tumor extension and vascularization through computerized tomography (CT) scan and angiography and the patient's age; Nasoangiofibroma juvenil - estudo da extensao e vascularizacao do tumor pela tomografia computadorizada e angiografia, e da idade do paciente

    Energy Technology Data Exchange (ETDEWEB)

    Sennes, Luiz Ubirajara

    1997-07-01

    The juvenile nasopharyngeal angiofibroma is a rare benign tumor that affects male adolescents. It is a fibro-vascular tumor with an exuberant intra tumor blood flow and irrigated by several arteries. It originates from the lateral and posterior region of the nasal cavity and, due to its characteristic multidirectional growth, widely affects the paranasal sinuses and skull base, sometimes invading the cranial fossa or the cheek. The determinant factors of its growth and vascularisation are unknown. Attempting to clarify them, 33 patients from the University of Sao Paulo Medicine were studied from 1983 to 1995, with complete history and radiological documentation (CT scan and angiography), as well as with histological confirmation of the diagnosis. In order to take only tumors with natural evolution, patients with recidivant tumor and those already submitted to any previous treatment were excluded. The parameters evaluate were: patient age and tumor extension (by classification, degree of invasion and number of compromised sites in CT scan) and vascularisation (by number and degree of participation of bilateral arteries in angiography). The se data were tabled and correlated one with each other. (author)

  4. 4D computed tomography scans for conformal thoracic treatment planning: is a single scan sufficient to capture thoracic tumor motion?

    Science.gov (United States)

    Tseng, Yolanda D.; Wootton, Landon; Nyflot, Matthew; Apisarnthanarax, Smith; Rengan, Ramesh; Bloch, Charles; Sandison, George; St. James, Sara

    2018-01-01

    Four dimensional computed tomography (4DCT) scans are routinely used in radiation therapy to determine the internal treatment volume for targets that are moving (e.g. lung tumors). The use of these studies has allowed clinicians to create target volumes based upon the motion of the tumor during the imaging study. The purpose of this work is to determine if a target volume based on a single 4DCT scan at simulation is sufficient to capture thoracic motion. Phantom studies were performed to determine expected differences between volumes contoured on 4DCT scans and those on the evaluation CT scans (slow scans). Evaluation CT scans acquired during treatment of 11 patients were compared to the 4DCT scans used for treatment planning. The images were assessed to determine if the target remained within the target volume determined during the first 4DCT scan. A total of 55 slow scans were compared to the 11 planning 4DCT scans. Small differences were observed in phantom between the 4DCT volumes and the slow scan volumes, with a maximum of 2.9%, that can be attributed to minor differences in contouring and the ability of the 4DCT scan to adequately capture motion at the apex and base of the motion trajectory. Larger differences were observed in the patients studied, up to a maximum volume difference of 33.4%. These results demonstrate that a single 4DCT scan is not adequate to capture all thoracic motion throughout treatment.

  5. Fluorodeoxyglucose positron emission tomography scan may be helpful in the case of ductal variant prostate cancer when prostate specific membrane antigen ligand positron emission tomography scan is negative

    International Nuclear Information System (INIS)

    McEwan, Louise M.; Wong, David; Yaxley, John

    2017-01-01

    Gallium-68 prostate specific membrane antigen ligand (Ga-68 PSMA) positron emission tomography/computed tomography (PET/CT) scanning is emerging as a useful imaging modality for the staging of suspected and known recurrent or metastatic prostate cancer and in staging of newly diagnosed higher grade prostate cancer. However, we have observed at our institution that in some cases of the more aggressive ductal variant, Ga-68 PSMA uptake has sometimes been poor compared with prominent 18-fluorodeoxyglucose (F-18 FDG) avidity seen in F-18 FDG PET/CT, which would suggest that FDG PET/CT scans are important in staging of ductal pattern prostate cancer.

  6. 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

  7. 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.

  8. 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)

  9. Nasal Anthropometry on Facial Computed Tomography Scans for Rhinoplasty in Koreans

    Directory of Open Access Journals (Sweden)

    Kyung Min Moon

    2013-09-01

    Full Text Available BackgroundCephalometric analysis is essential for planning treatment in maxillofacial and aesthetic facial surgery. Although photometric analysis of the Korean nose has been attempted in the past, anthropometry of the deeper nasal structures in the same population based on computerized tomography (CT has not been published. We therefore measured three anthropometric parameters of the nose on CT scans in our clinical series of patients.MethodsWe conducted the current retrospective study of a total of 100 patients (n=100 who underwent a CT-guided radiological measurement at our institution during a period ranging from January of 2008 to August of 2010. In these patients, we took three anthropometric measurements: the nasofrontal angle, the pyramidal angle, and the linear distance between the nasion and the tip of the nasal bone.ResultsThe mean nasofrontal angle was 131.14° in the male patients and 140.70° in the female patients. The mean linear distance between the nasion and the tip of the nasal bone was 21.28 mm and 18.02 mm, respectively. The mean nasal pyramidal angle was 112.89° and 103.25° at the level of the nasal root, 117.49° and 115.60° at the middle level of the nasal bone, and 127.99° and 125.04° at the level of the tip of the nasal bone, respectively.ConclusionsIn conclusion, our data will be helpful in the preparation of silicone implants for augmentation and/or corrective rhinoplasty in ethnic Korean people.

  10. Promising role of single photon emission computed tomography/computed tomography in Meckel's scan

    International Nuclear Information System (INIS)

    Jain, Anurag; Chauhan, MS; Pandit, AG; Kumar, Rajeev; Sharma, Amit

    2012-01-01

    Meckel's scan is a common procedure performed in nuclear medicine. Single-photon emission computed tomography/computed tomography (SPECT/CT) in a suspected case of heterotopic location of gastric mucosa can increase the accuracy of its anatomic localization. We present two suspected cases of Meckel's diverticulum in, which SPECT/CT co-registration has helped in better localization of the pathology

  11. Accuracy of a computed tomography scanning procedure to manufacture digital models.

    NARCIS (Netherlands)

    Darroudi, A.M.; Kuijpers-Jagtman, A.M.; Ongkosuwito, E.M.; Suttorp, C.M.; Bronkhorst, E.M.; Breuning, K.H.

    2017-01-01

    INTRODUCTION: Accurate articulation of the digital dental casts is crucial in orthodontic diagnosis and treatment planning. We aimed to determine the accuracy of manufacturing digital dental casts from computed tomography scanning of plaster casts regarding linear dimensions and interarch

  12. New possibilities of three-dimensional reconstruction of computed tomography scans

    International Nuclear Information System (INIS)

    Herman, M.; Tarjan, Z.; Pozzi-Mucelli, R.S.

    1996-01-01

    Three-dimensional (3D) computed tomography (CT) scan reconstructions provide impressive and illustrative images of various parts of the human body. Such images are reconstructed from a series of basic CT scans by dedicated software. The state of the art in 3D computed tomography is demonstrated with emphasis on the imaging of soft tissues. Examples are presented of imaging the craniofacial and maxillofacial complex, central nervous system, cardiovascular system, musculoskeletal system, gastrointestinal and urogenital systems, and respiratory system, and their potential in clinical practice is discussed. Although contributing no new essential diagnostic information against conventional CT scans, 3D scans can help in spatial orientation. 11 figs., 25 refs

  13. 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

  14. 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)

  15. Accurately localizing the thyroid tissue in mature cystic teratoma of ovary by single-photon emission computerized tomography/computerized tomography

    International Nuclear Information System (INIS)

    Demir, Yusuf; Üçler, Rıfkı; Alkiş, İsmet; Bulut, Gülay

    2015-01-01

    A 30-year-old woman with hyperthyroidism was admitted to hospital. Although increased thyroid function was found, the gland was normal in ultrasonography (USG). Additionally, thyroid iodine uptake and Tc-99m pertechnetate scintigraphy was normal. Abdomen USG detected a cystic pelvic mass in left ovary. A whole-body scan was performed 48 hours after oral ingestion of 29.6 MBq (0.8 mCi) I-131 (iodine-131) revealed a round structure located to the left lower abdomen. Iodine uptake was detected in this cyst which was compatible with functional thyroid tissue demonstrated by SPECT/CT. The patient was underwent surgical operation and histopathology confirmed mature cystic teratoma. Accurate localization and depiction of thyroid tissue in ovary mass was provided with SPECT/CT

  16. 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.

  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. 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

  19. 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.

  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. The development of an x-ray computerized tomography (CT) experimental system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G N; Kijek, M M; Millar, J J [Royal Melbourne Inst. of Tech., VIC (Australia)

    1994-12-31

    This paper describes a prototype experimental CT system that has been recently developed at Applied Physics, RMIT/ Physics, La Trobe UCNV. The system incorporates the scanning mode of the first generation CAT-scanner and is designed to perform the scanning of small objects. A microcomputer is used to control the scanning motions and data collection. The performance of the system was examined by scanning a ball-point pen. 8 refs., 4 figs.

  2. The development of an x-ray computerized tomography (CT) experimental system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G.N.; Kijek, M.M.; Millar, J.J. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    This paper describes a prototype experimental CT system that has been recently developed at Applied Physics, RMIT/ Physics, La Trobe UCNV. The system incorporates the scanning mode of the first generation CAT-scanner and is designed to perform the scanning of small objects. A microcomputer is used to control the scanning motions and data collection. The performance of the system was examined by scanning a ball-point pen. 8 refs., 4 figs.

  3. Visual scanning training for neglect after stroke with and without a computerized lane tracking dual task

    Directory of Open Access Journals (Sweden)

    M.E. eVan Kessel

    2013-07-01

    Full Text Available Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might enhance training results. In the present study, a dual task training component was added to a visual scanning training (i.e. Training di Scanning Visuospaziale – TSVS; Pizzamiglio et al., 1990. Twenty-nine subacute right hemisphere stroke patients were semi-randomly assigned to an experimental (N=14 or a control group (N=15. Patients received 30 training sessions during six weeks. TSVS consisted of four standardized tasks (digit detection, reading/copying, copying drawings and figure description. Moreover, a driving simulator task was integrated in the training procedure. Control patients practiced a single lane tracking task for two days a week during six weeks. The experimental group was administered the same training schedule, but in weeks 4-6 of the training, the TSVS digit detection task was combined with lane tracking on the same projection screen, so as to create a dual task (CVRT-TR. Various neglect tests and driving simulator tasks were administered before and after training. No significant group and interaction effects were found that might reflect additional positive effects of dual task training. Significant improvements after training were observed in both groups taken together on most assessment tasks. Ameliorations were generally not correlated to post onset time, but spontaneous recovery, test-retest variability and learning effects could not be ruled out completely, since these were not controlled for. Future research might focus on increasing the amount of dual task training, the implementation of progressive difficulty levels in the driving simulator tasks and further exploration of relationships between dual task training and daily

  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. 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.

  6. The sensitivity of computed tomography (CT) scans in detecting trauma: are CT scans reliable enough for courtroom testimony?

    Science.gov (United States)

    Molina, D Kimberley; Nichols, Joanna J; Dimaio, Vincent J M

    2007-09-01

    Rapid and accurate recognition of traumatic injuries is extremely important in emergency room and surgical settings. Emergency departments depend on computed tomography (CT) scans to provide rapid, accurate injury assessment. We conducted an analysis of all traumatic deaths autopsied at the Bexar County Medical Examiner's Office in which perimortem medical imaging (CT scan) was performed to assess the reliability of the CT scan in detecting trauma with sufficient accuracy for courtroom testimony. Cases were included in the study if an autopsy was conducted, a CT scan was performed within 24 hours before death, and there was no surgical intervention. Analysis was performed to assess the correlation between the autopsy and CT scan results. Sensitivity, specificity, positive predictive value, and negative predictive value were defined for the CT scan based on the autopsy results. The sensitivity of the CT scan ranged from 0% for cerebral lacerations, cervical vertebral body fractures, cardiac injury, and hollow viscus injury to 75% for liver injury. This study reveals that CT scans are an inadequate detection tool for forensic pathologists, where a definitive diagnosis is required, because they have a low level of accuracy in detecting traumatic injuries. CT scans may be adequate for clinicians in the emergency room setting, but are inadequate for courtroom testimony. If the evidence of trauma is based solely on CT scan reports, there is a high possibility of erroneous accusations, indictments, and convictions.

  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. 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)

  9. Tangential scanning of hardwood logs: developing an industrial computer tomography scanner

    Science.gov (United States)

    Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson

    1999-01-01

    It is generally believed that noninvasive scanning of hardwood logs such as computer tomography (CT) scanning prior to initial breakdown will greatly improve the processing of logs into lumber. This belief, however, has not translated into rapid development and widespread installation of industrial CT scanners for log processing. The roadblock has been more operational...

  10. Method and apparatus for scanning x-ray tomography

    International Nuclear Information System (INIS)

    Albert, R.D.

    1988-01-01

    In a method of producing a tomographic image of a subject that includes the steps of generating X-rays at a moving origin point by directing a charged particle beam to a target surface, deflecting the charged particle beam to travel the origin point through a predetermined raster scan at the surface, detecting variations of X-ray intensity during the course of the raster scan at spaced apart detection points situated at the opposite side of the subject from the origin point, generating a first sequence of data values that is indicative of variations of X-ray intensity at a first of the detection points at successive times during the course of the raster scan and generating at least a second sequence of data values that is indicative of variations of X-ray intensity at a second of the detection points at successive times during the course of the same raster scan, the improvement is described comprising: combining successive individual data values of the first sequence that are generated by X-rays from successive particular locations in the raster scan with at least individual data values of the second sequence that are generated by X-rays from predetermined successive different locations in the same raster scan in order to produce a composite sequence of data values, and producing an image corresponding to at least a portion of the raster scan which depicts variations of the magnitude of successive data values of the composite sequence

  11. The clinical value of computerized axial tomography in patients without focal neurological features

    International Nuclear Information System (INIS)

    Lundorf, E.; Nielson, M.B.

    1985-01-01

    74 randomly selected patients with non-focal cerebral symptoms and a normal neurologic examination were referred from neurologic departments to CT scan of the brain. 29 patients had generalised epilepsy of long duration. In 26 patients (90%) with epilepsy the Ct scan was normal. 2 patients (7%) had cerebral atrophy, 1 (3%) showed porencephaly (.) 41 (91%) of the patients without epileptic features had a normal CT scan. 4 (9%) presented cerebral atrophy. In this survey, Ct scanning did not contribute to a focal diagnosis in patients with diffuse cerebral features. (orig.) [de

  12. 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

  13. Feasibility study of archaeological structures scanning by muon tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, H.; Katsanevas, S.; Tonazzo, A. [Laboratoire Astroparticule et Cosmologie (APC) - Université Paris 7. Paris (France); Carloganu, C.; Niess, V. [Laboratoire de Physique Corpusculaire (LPC) - Université Blaise Pascal. Clermont - Ferrand (France); Gibert, D. [Géosciences Rennes - Université de Rennes 1. Rennes (France); Marteau, J. [Institute de Physique Nucléaire de Lyon (IPNL) - Université de Lyon (UCBL). Lyon (France)

    2015-08-17

    One of the main concerns in archaeology is to find of a method to study precisely archaeological structures in the least invasive way possible to avoid damage. The requirement of preserving the structures integrity prevents, in the case of pyramids or tumuli, the study of any internal structure (halls or tombs) which are not reachable by existing corridors. One non-invasive method is the muon tomography. By placing a detector which allows to register the muon direction after the structure, it is possible to have an idea of its composition based on the attenuation of the muon flux, which depends on the material length and density that muons have crossed. This technique, alone or together with other exploration techniques as seismic tomography or electrical resistivity tomography, can provide useful information about the internal structure of the archaeological form that can not be obtained by conventional archaeological methods. In this work, the time measurement necessary to obtain a significant result about the composition of an archaeological structure is estimated. To do that, a Monte Carlo simulation framework based on the MUSIC software, properly tuned for this study, has been developed. The particular case of the Kastas Amfipoli Macedonian tumulus has been considered to perform the simulations.

  14. Feasibility study of archaeological structures scanning by muon tomography

    International Nuclear Information System (INIS)

    Gómez, H.; Katsanevas, S.; Tonazzo, A.; Carloganu, C.; Niess, V.; Gibert, D.; Marteau, J.

    2015-01-01

    One of the main concerns in archaeology is to find of a method to study precisely archaeological structures in the least invasive way possible to avoid damage. The requirement of preserving the structures integrity prevents, in the case of pyramids or tumuli, the study of any internal structure (halls or tombs) which are not reachable by existing corridors. One non-invasive method is the muon tomography. By placing a detector which allows to register the muon direction after the structure, it is possible to have an idea of its composition based on the attenuation of the muon flux, which depends on the material length and density that muons have crossed. This technique, alone or together with other exploration techniques as seismic tomography or electrical resistivity tomography, can provide useful information about the internal structure of the archaeological form that can not be obtained by conventional archaeological methods. In this work, the time measurement necessary to obtain a significant result about the composition of an archaeological structure is estimated. To do that, a Monte Carlo simulation framework based on the MUSIC software, properly tuned for this study, has been developed. The particular case of the Kastas Amfipoli Macedonian tumulus has been considered to perform the simulations

  15. Feasibility study of archaeological structures scanning by muon tomography

    Science.gov (United States)

    Gómez, H.; Carloganu, C.; Gibert, D.; Marteau, J.; Niess, V.; Katsanevas, S.; Tonazzo, A.

    2015-08-01

    One of the main concerns in archaeology is to find of a method to study precisely archaeological structures in the least invasive way possible to avoid damage. The requirement of preserving the structures integrity prevents, in the case of pyramids or tumuli, the study of any internal structure (halls or tombs) which are not reachable by existing corridors. One non-invasive method is the muon tomography. By placing a detector which allows to register the muon direction after the structure, it is possible to have an idea of its composition based on the attenuation of the muon flux, which depends on the material length and density that muons have crossed. This technique, alone or together with other exploration techniques as seismic tomography or electrical resistivity tomography, can provide useful information about the internal structure of the archaeological form that can not be obtained by conventional archaeological methods. In this work, the time measurement necessary to obtain a significant result about the composition of an archaeological structure is estimated. To do that, a Monte Carlo simulation framework based on the MUSIC software, properly tuned for this study, has been developed. The particular case of the Kastas Amfipoli Macedonian tumulus has been considered to perform the simulations.

  16. 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)

  17. Simultaneous fast scanning XRF, dark field, phase-, and absorption contrast tomography

    Science.gov (United States)

    Medjoubi, Kadda; Bonissent, Alain; Leclercq, Nicolas; Langlois, Florent; Mercère, Pascal; Somogyi, Andrea

    2013-09-01

    Scanning hard X-ray nanoprobe imaging provides a unique tool for probing specimens with high sensitivity and large penetration depth. Moreover, the combination of complementary techniques such as X-ray fluorescence, absorption, phase contrast and dark field imaging gives complete quantitative information on the sample structure, composition and chemistry. The multi-technique "FLYSCAN" data acquisition scheme developed at Synchrotron SOLEIL permits to perform fast continuous scanning imaging and as such makes scanning tomography techniques feasible in a time-frame well-adapted to typical user experiments. Here we present the recent results of simultaneous fast scanning multi-technique tomography performed at Soleil. This fast scanning scheme will be implemented at the Nanoscopium beamline for large field of view 2D and 3D multimodal imaging.

  18. Ceftriaxone-associated pancreatitis captured on serial computed tomography scans

    Directory of Open Access Journals (Sweden)

    Nozomu Nakagawa, MD

    2018-02-01

    Full Text Available A 74-year-old man was treated with ceftriaxone for 5 days and subsequently experienced epigastric pain. Computed tomography (CT was performed 7 and 3 days before epigastralgia. Although the first CT image revealed no radiographic signs in his biliary system, the second CT image revealed dense radiopaque material in the gallbladder lumen. The third CT image, taken at symptom onset, showed high density in the common bile duct and enlargement of the pancreatic head. This is a very rare case of pseudolithiasis involving the common bile duct, as captured on a series of CT images.

  19. Ceftriaxone-associated pancreatitis captured on serial computed tomography scans.

    Science.gov (United States)

    Nakagawa, Nozomu; Ochi, Nobuaki; Yamane, Hiromichi; Honda, Yoshihiro; Nagasaki, Yasunari; Urata, Noriyo; Nakanishi, Hidekazu; Kawamoto, Hirofumi; Takigawa, Nagio

    2018-02-01

    A 74-year-old man was treated with ceftriaxone for 5 days and subsequently experienced epigastric pain. Computed tomography (CT) was performed 7 and 3 days before epigastralgia. Although the first CT image revealed no radiographic signs in his biliary system, the second CT image revealed dense radiopaque material in the gallbladder lumen. The third CT image, taken at symptom onset, showed high density in the common bile duct and enlargement of the pancreatic head. This is a very rare case of pseudolithiasis involving the common bile duct, as captured on a series of CT images.

  20. Methanol poisoning: brain computed tomography scan findings in four patients

    International Nuclear Information System (INIS)

    Patankar, T.; Prasad, S.; Rathod, K.; Bichile, L.; Karnad, D.

    1999-01-01

    Methanol, through its chief metabolite, formate, causes irreversible neurological damage. Methanol intoxication produces classic neuropathological changes and characteristic imaging findings. Computed tomography was performed on four patients who presented with a history of methanol poisoning. Prominent, hypodense lesions in the lentilform nuclei and peripheral white matter, sometimes with haemorrhage, were the characteristic imaging findings in the present patients. It was noted that the severity and extent of necrosis of the lentilform nuclei do not necessarily correlate with the clinical outcome. Copyright (1999) Blackwell Science Pty Ltd

  1. Cerebral toxoplasmosis in AIDS - computerized tomography evaluation; Toxoplasmose cerebral na SIDA - avaliacao por tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Regina Coeli Fonseca [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Hospital Universitario Antonio Pedro. Servico de Radiologia; Narchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia

    1999-06-01

    Cerebral toxoplasmosis is a disease that affects many AIDS's patients. FOr this paper 46 patients with confirmed cases of cerebral toxoplasmosis who did a CT scan between March, 1994 and September, 1997 were examined. Single lesions were found in 28.3% of the patients. The lesions were more frequently detected in the basal ganglia and the frontal lobes. No lesion was larger than 4 cm. As regards the contrast enhancing of the lesions on a CT scan we observed that 54.5% of the lesions had a ring-like contrast enhancing, 36.4% had a nodular contrast enhancing and 6% had a heterogeneous form. After the 21st day of treatment we noticed an improvement in the aspect of the patients'lesions. The improvement of the lesions could be seen through a reduction of the edematous halo, a reduction of the lesion size and a modification in the contrast enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility with cerebral toxoplasmosis, as well as to monitor these patients during treatment. (author)

  2. Use of routine computed tomography brain scanning of psychiatry patients

    International Nuclear Information System (INIS)

    Agzarian, M.J.; Chryssidis, S.; Davies, R.P.; Pozza, C.H.

    2006-01-01

    The aim of this study was to evaluate the usefulness of CT of the brain in patients presenting with a psychiatric condition without focal neurological signs. The reports of 397 consecutive CT brain scans of patients presenting to two acute tertiary hospital psychiatric services over a 2-year period were assessed retrospectively. Of the 397 patients, 241 had psychosis, 87 had depression, 44 had bipolar affective disorder, seven had alcohol dependence, five had dementia, and the remaining 13 had a variety of diagnoses including personality disorder and transient ischaemic attack. Findings on 377 (95%) of the CT scans showed no abnormality. Specific abnormalities were described in 20 (5%) of the CT scans. Three scans showed non-specific minor abnormalities, which, when followed up by MRI, showed no relevant abnormality. All the abnormalities shown on CT were considered to be clinically unrelated to the patient's psychiatric condition. In conclusion, the pretest probability of finding a space-occupying lesion or other pertinent abnormality in patients presenting with psychiatric illnesses in this retrospective study appears not to be greater than that of the general population. The outcome of this study could be implemented to develop a clinical pathway for limiting assessment by CT for possible organic pathology in acute psychiatric illness. Copyright (2006) Blackwell Science Pty Ltd

  3. 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)

  4. 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)

  5. Role of Postmortem Multislice Computed Tomography Scan in Close Blunt Head Injury

    Directory of Open Access Journals (Sweden)

    Prijo Sidipratomo

    2014-08-01

    Full Text Available BACKGROUND: Conventional autopsy in Indonesia is not well accepted as it is contrary to religion and culture. New radiological imaging method such as multislice computed tomography (MSCT scan has potential to be a diagnostic tool in forensic pathology. The purpose of this study is to determine the ability of MSCT scan in finding abnormalities in close blunt head injury compared with autopsy. METHODS: This study used descriptive qualitative method. Postmortem cases in Department of Forensic Medicine and Radiology of Dr. Cipto Mangunkusumo Hospital were selected based on inclusion criteria. Then MSCT scan and autopsy were conducted. MSCT scan and autopsy results were compared and analyzed. RESULTS: There were 491 postmortem cases of blunt head injury. However, only 10 cases fulfilled inclusion criteria. Subarachnoid haemorrhages were identified 100% with MSCT scan and 80% with autopsy. Cerebral oedemas were identified 100% either with MSCT scan and autopsy. Subdural haemorrhages were identified 100% with MSCT scan, while 50% with autopsy. Multiple fractures were identified 80% with MSCT scan, while 40% with auto. CONCLUSIONS: MSCT scan showed a sensitive detection in finding abnormalities in close blunt head injury. Therefore it could be as an alternative choice of examination in close blunt head injury cases. KEYWORDS: multislice computed tomography scan, postmortem, blunt head injury, autopsy.

  6. 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)

  7. Use and impact of positron computed tomography scanning in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Mazziotta, J.C.; Engel, J. Jr.

    1984-01-01

    Through the effective combination of instrumentation, tracer kinetic principles, and radiopharmaceuticals, positron computed tomography (PET) allows for the analytic, noninvasive measurement of local tissue physiology in humans. A large number of studies have already been performed in patients with epilepsy using 18F-fluorodeoxyglucose (FDG) to measure local cerebral glucose utilization. In patients with complex partial epilepsy who are candidates for surgery, hypometabolic zones have been seen consistently (70%) in the interictal state. The complex anatomical and pathophysiological investigation of these hypometabolic zones is discussed. Ictal studies of patients with partial seizures have demonstrated a much more variable metabolic pattern which usually consists of hypermetabolism relative to baseline or interictal studies. Generalized epilepsy produced by electroconvulsive shock and petit mal epilepsy have been studied using FDG to estimate glucose metabolism.

  8. Assessment of the ring enhancement of the brain abscess by computerized tomography

    International Nuclear Information System (INIS)

    Tanaka, Keisei; Yasunaga, Akio; Kawano, Teruaki; Miyazaki, Hisaya; Mori, Kazuo

    1982-01-01

    The underlying mechanism concerning the ring enhancement of the CT scan was considered in three cases of brain abscess. The first case, a 55-year-old male, was admitted 1 week after the onset of symptoms. A CT scan showed a contrast ring enhancement with perifocal severe edema in the right temporal lobe. A subsequent CT scan, after the administration of antibiotics and steroid treatment, showed no contrast ring enhancement. However, it reappeared after discontinuation of treatment and the disappeared again following the readministration of antibiotics. In the acute stage, functional changes in the local vessels (failure of BBB) caused by inflammation might have been responsible for the ring enhancement. The second case, an 8-year-old girl, was abmitted 1 month after the onset of symptoms. An initial CT scan showed large lobulated abscesses in the right fronto-temporal lobe, with ring enhancement. The follow-up CT scans, one and two years after onset, still showed a small disc enhancement in the temporallobe. The third case, a 10-year-old boy with tetoralogy of Fallot, developed multiple cerebral abscesses in the left frontal lobe. In spite of medical treatment, his clinical status and CT findings did not show any remarkable inprovement, and so an extracapsular excision of the abscesses was performed. Serial CT scans. however, revealed the persistence of the ring sign even after a complete excision of the brain abscesses. Microscopic findings of the excised abscess wall showed a marked, vascular-rich granulation, the outer part of which remained in situ and must have been responsible for the ring enhancement even after the extracapsular excision of the brain abscesses. (author)

  9. 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

  10. 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)

  11. 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.).

  12. 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.)

  13. 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.)

  14. 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)

  15. 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 ...

  16. Relevance of computerized tomography in the preoperative evaluation of patients with vulvar cancer

    DEFF Research Database (Denmark)

    Andersen, Kjeld; Zobbe, Vibeke; Thranov, Ingrid Regitze

    2015-01-01

    University Hospital, Rigshospitalet. The patients underwent a gynecological examination, chest x-ray and a preoperative CT scanning of the chest, abdomen and pelvis. It was registered whether the radiological findings regarding the extent of the tumor, lymph node involvement, incidental findings...

  17. 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)

  18. 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

  19. 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.

  20. 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

  1. 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%.

  2. 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)

  3. 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

    As we all know, Nuclear Medicine is the medical science using nuclear radiation for diagnosis, treatment and research. Nuclear Medicine, in contrast to Radiology, makes use of unsealed sources of radiation. Nuclear Medicine a few years ago has partly offered Nuclear Cardiology, the most lucrative of all Nuclear Medicine "children" at that time, to Cardiology. Radiology, has succeeded in being recognized by the European Union Authorities as Clinical Radiology. The word "clinical" offers greater independence to Clinical Radiology and makes it difficult for such a specialty to relinquish any of its equipment i.e. the diagnostic CT scan or the newly developed fast angiography CT, to other specialties. Contrary to Clinical Radiology, Nuclear Medicine being a laboratory specialty in most countries seems to have no right to deny offering, after some period of "proper certified education", its PET camera to Clinical Radiologists. Nuclear Medicine by virtue of its unique diagnostic techniques and treatments, is and should be recognized as a "Clinical Specialty" The interference of other specialties in the fields of Nuclear Medicine is also indicated by the fact that in vitro techniques of Nuclear Medicine are often used by Endocrinologists and Oncologists in their own laboratories. Also in some hospitals the Director of the Radiology Department acts as the Director of Nuclear Medicine Laboratory. Finally at present, Radiologists wish after "proper certified education", to be on equal terms in charge of the new hybridic equipment, the PET/CT scanner. If that is followed to happen, Nuclear Medicine will be in a difficult position losing at least part of PET and consequently should ask for help from its "Overlords and Protectors" i.e. the National and the European Societies of Nuclear Medicine and the Society of Nuclear Medicine of the United States of America. Radiology as a specialty participating om equal terms with the PET camera will then include the study of: a) "open

  4. Role of Postmortem Multislice Computed Tomography Scan in Close Blunt Head Injury

    OpenAIRE

    Sidipratomo, Prijo; Prija, Trijono Karmawan Sukana; Murtala, Bachtiar; Purwadianto, Agus; Lawrence, Gatot Susilo

    2014-01-01

    BACKGROUND: Conventional autopsy in Indonesia is not well accepted as it is contrary to religion and culture. New radiological imaging method such as multislice computed tomography (MSCT) scan has potential to be a diagnostic tool in forensic pathology. The purpose of this study is to determine the ability of MSCT scan in finding abnormalities in close blunt head injury compared with autopsy. METHODS: This study used descriptive qualitative method. Postmortem cases in Department of Forensic M...

  5. Integration of Digital Dental Casts in Cone-Beam Computed Tomography Scans

    OpenAIRE

    Rangel, Frits A.; Maal, Thomas J. J.; Bergé, Stefaan J.; Kuijpers-Jagtman, Anne Marie

    2012-01-01

    Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors have described methods to integrate digital dental casts into CBCT scans, but all reported methods have drawbacks. The aim of this feasibility study is to present a new simplified method to integrate digital dental casts into CBCT scans. In a patient scheduled for orthognathic ...

  6. 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.

  7. 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 ...

  8. Positron emission tomography scans on kanji and kana

    International Nuclear Information System (INIS)

    Sakurai, Yasuhisa

    2002-01-01

    We reanalyzed our positron emission tomography (PET) study on reading of Japanese kanji (morphogram) words, kana (phonogram) words and kana nonwords, using Statistical Parametric Mapping (SPM). The basal occipital and occipito-temporal areas were activated in common, among which activity was most pronounced in the fusiform/inferior temporal gyri with kanji and in the inferior occipital gyrus with kana. The results were consistent with the clinical observations that damage to the posterior inferior temporal cortex including the fusiform/inferior temporal gyri causes alexia with agraphia for kanji, whereas damage to the posterior occipital area including the inferior occipital gyrus causes pure alexia for kana. Bases on the present results and the lesion studies, a dual-route hypothesis that modifies Iwata's model of reading about the Japanese language was proposed. That is, the middle occipital gyrus, deep perisylvian temporoparietal cortex and posterior temporal gyrus constitute a dorsal route for reading and process phonology for words, whereas the inferior occipital, fusiform and posterior inferior temporal gyri constitute a ventral route for reading and process orthography and lexico-semantics for words. The ventral route may gain dominance in reading, according as a word is repeatedly presented. (author)

  9. Deriving motion from megavoltage localization cone beam computed tomography scans

    International Nuclear Information System (INIS)

    Alfredo C Siochi, R

    2009-01-01

    Cone beam computed tomography (CBCT) projection data consist of views of a moving point (e.g. diaphragm apex). The point is selected in identification views of extreme motion (two inhale, two exhale). The room coordinates of the extreme points are determined by source-to-view ray tracing intersections. Projected to other views, these points become opposite corners of a motion-bounding box. The view coordinates of the point, relative to the box, are used to interpolate between extreme room coordinates. Along with the views' time stamps, this provides the point's room coordinates as a function of time. CBCT-derived trajectories of a tungsten pin, moving 3 cm cranio-caudally and 1 cm elsewhere, deviate from expected ones by at most 1.06 mm. When deviations from the ideal imaging geometry are considered, mean errors are less than 0.2 mm. While CBCT-derived cranio-caudal positions are insensitive to the choice of identification views, the bounding box determination requires view separations between 15 and 163 deg. Inhale views with the two largest amplitudes should be used, though corrections can account for different amplitudes. The information could be used to calibrate motion surrogates, adaptively define phase triggers immediately before gated radiotherapy and provide phase and amplitude sorting for 4D CBCT.

  10. Xenon as an inhalation contrast medium in the computerized tomography of the brain

    International Nuclear Information System (INIS)

    Iwabuchi, Sadamu; Hagihara, Teruhisa; Kozu, Jin; Amaki, Ichita

    1980-01-01

    Non-radioactive Xenon (Xe) inhalation CT scanning was performed in 5 normal adults. The following results were obtained: 1. On Xe inhalation CT scanning, the use of a true closed circuit very greatly reduced the consumption of the expensive Xe. 2. Less than 60% Xe in oxygen would have an advantage in that there would be no necessity for the intubation of the patients before the Xe enhancement. 3. Xe enhanced the brain substance itself, especially the cortex, the basal ganglia, and the thalamus. 4. To obtain good results and decrease the general use of anesthetia, it is desirable to use 60% Xe in oxygen. 5. Optimum results were obtained within 1 - 3 minutes after Xe inhalation. This technique deserves an important place among brain-diagnostic techniques in spite of the necessity of using general anesthetia and the expensiveness of Xe. (author)

  11. Cerebral computerized tomography findings in AIDS patients; Cerebrale CT-funn ved AIDS

    Energy Technology Data Exchange (ETDEWEB)

    Hol, P.K.; Dunlop, O. [Ullevaal Sykehus, Oslo (Norway)

    1997-09-01

    A cerebral CT was performed in 82 of 525 AIDS patients, with positive findings in 46 cases. These findings included cerebral atrophy in 28 cases, pathological demyelinisation in two, progressive multifocal leukoencephalopathy in one, toxoplasmoses in 11, lymphomas in seven, infarction in one and one subdural haematoma. The radiological findings are correlated to pathology and clinical symptoms. The authors point out the importance of these findings for correct interpretation of the CT scans. 11 refs., 7 figs., 2 tabs.

  12. A case of absence of the septum pellucidum accompanied with hydrocephalus and detected by computerized tomography

    International Nuclear Information System (INIS)

    Tominaga, Komei; Kobayashi, Eiki; Yamamoto, Kunimitsu; Asakura, Tetsuhiko

    1981-01-01

    A case of absence of the septum pellucidum accompanied with hydrocephalus in 56 years-old woman who had complained headache, dizziness and numbness of left leg was reported. Absence of the septum pellucidum in this case had not been detected untill CT scan was performed. Ventriculoperitoneal shunt was performed, then her complaints were cleared up. The discussion was limited as far as possible to absence of the septum pellucidum without agenesis of the corpus callosum with a few references. Encephalographic characteristics of absence of the septum pellucidum were firstly noted by Foster in 1935. The real prevelence should lie at about 1 : 400 in a sufficiently large encephalographical series, which should be an estimate between 2 and 3 per 100,000 of population. Encephalography, although, afflicts patients with headache, nausea and vomiting, moreover it accompanied with possible intracranial infection. The other hand, CT scan has cleared up these problems, we can perform it easily in any cases, and know about status of the septum pellucidum. Further examination for more distinct information are took by coronal section and ''high definition 5 mm slice thickness'' of CT scan. (author)

  13. 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)

  14. 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.

  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. 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

  17. Dosimetry study using head dummy in computed tomography scans

    International Nuclear Information System (INIS)

    Ladino G, A. M.; Do Carmo S, P.; Prata M, A.

    2017-10-01

    The concern in the amounts of radiation doses deposited in the patients is still great because the computed tomography (CT) exams are currently the ones that reach the highest levels of radiation deposited in the population. Brazilian legislation regulates the levels of doses deposited in patients since it is limited to estimating a maximum amount, depending on the region of the body to be exposed. Therefore is necessary to determine the amount of dose that is deposited in patients depending on the routine protocols used in the radio diagnosis services and thus, propose an optimization of these under the principles referring to dose limitation, optimization of radiological protection and of course, the justification of the practices. Experiments were conducted to determine the dose profile for routine head exams in an adult patient, using a physical simulator object of polymethylmethacrylate (PMMA) in cylindrical format with 4 peripheral orifices and one central one. Strips of radiochromic film were introduced in each of the holes to record the dose profile in each region and thus determine the amount of dose deposited in the entire volume of the simulator object. A General Electric 64-channel tomograph, typical of the radiology service, was used for voltages of 80, 100 and 120 kV with a fixed current of 200 ma, finding dose levels between 6.24 and 23.73 mGy. Noise analysis of the images was performed, finding that all of them met the acceptable diagnostic parameters. An optimized protocol is proposed for head CT exams with a voltage of 80 kV for images with a noise index of 0.5%. (Author)

  18. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    International Nuclear Information System (INIS)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-01

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke’s tabulated data

  19. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    Science.gov (United States)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-01

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke's tabulated data.

  20. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao [Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8573 (Japan)

    2016-01-28

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke’s tabulated data.

  1. Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

    Science.gov (United States)

    An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

  2. Integration of digital dental casts in cone-beam computed tomography scans

    NARCIS (Netherlands)

    Rangel, F.A.; Maal, T.J.J.; Berge, S.J.; Kuijpers-Jagtman, A.M.

    2012-01-01

    Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors have described methods to integrate digital dental casts into CBCT scans, but all

  3. Performance analysis of a hybrid fingerprint extracted from optical coherence tomography fingertip scans

    CSIR Research Space (South Africa)

    Darlow, Luke N

    2016-06-01

    Full Text Available The Hybrid fingerprint is a local-quality-specific blend of the surface and internal fingerprints, extracted from optical coherence tomography scans. Owing to its origin, and the manner in which it is obtained, the Hybrid fingerprint is a high...

  4. Detection of vertical root fractures in endodontically treated teeth by a cone beam computed tomography scan

    NARCIS (Netherlands)

    Hassan, B.; Metska, M.E.; Özok, A.R.; van der Stelt, P.; Wesselink, P.R.

    2009-01-01

    Our aim was to compare the accuracy of cone beam computed tomography (CBCT) scans and periapical radiographs (PRs) in detecting vertical root fractures (VRFs) and to assess the influence of root canal filling (RCF) on fracture visibility. Eighty teeth were endodontically prepared and divided into

  5. Nano-tomography of porous geological materials using focused ion beam-scanning electron microscopy

    NARCIS (Netherlands)

    Liu, Yang; King, Helen E.; van Huis, Marijn A.; Drury, Martyn R.; Plümper, Oliver

    2016-01-01

    Tomographic analysis using focused ion beam-scanning electron microscopy (FIB-SEM) provides three-dimensional information about solid materials with a resolution of a few nanometres and thus bridges the gap between X-ray and transmission electron microscopic tomography techniques. This contribution

  6. Fentanyl Iontophoretic Transdermal System (IONSYS(®)) can be Safely used in the Hospital Environment with X-Rays, Computerized Tomography and Radiofrequency Identification Devices.

    Science.gov (United States)

    Lemke, John; Sardariani, Edmond; Phipps, Joseph Bradley; Patel, Niki; Itri, Loretta M; Caravelli, James; Viscusi, Eugene R

    2016-09-01

    Fentanyl iontophoretic transdermal system (fentanyl ITS, IONSYS(®)) is a patient-controlled analgesia system used for the management of acute postoperative pain, designed to be utilized in a hospital setting. The objective of the two studies was to determine if fentanyl ITS could be safely used with X-rays, computerized tomography (CT) scans and radiofrequency identification (RFID) devices. The ITS system has two components: controller and drug unit; the studies utilized ITS systems without fentanyl, referred to as the ITS Placebo system. The first study evaluated the effect of X-radiation on the operation of an ITS Placebo system. Five ITS Placebo systems were exposed to X-rays (20 and 200 mSv total radiation dose-the 200 mSv radiation dose represents a tenfold higher exposure than in clinical practice) while operating in the Ready Mode and five were exposed while operating in the Dose Mode. The second study evaluated the effect of RFID (worst-case scenario of direct contact with an RFID transmitter) on the operation of an ITS Placebo system. During these tests, observations of the user interface and measurements of output voltage confirmed proper function throughout all operational modes (Ready Mode, Dose Mode, End-of-Use Mode, and End-of-Life Mode). The ITS Placebo system met all specifications and no functional anomalies were observed during and following X-ray exposure at two radiation dose levels or exposure at six different combinations of RFID frequencies and field strengths. The performance of the ITS system was unaffected by X-ray exposure levels well beyond those associated with diagnostic X-rays and CT scans, and by exposure to radiofrequency field strengths typically generated by RFID devices. These results provide added confidence to clinicians that the fentanyl ITS system does not need to be removed during diagnostic X-rays and CT scans and can also be utilized in close proximity to RFID devices. The studies and writing of this manuscript were

  7. 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)

  8. Quantitative X-ray dark-field and phase tomography using single directional speckle scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongchang, E-mail: hongchang.wang@diamond.ac.uk; Kashyap, Yogesh; Sawhney, Kawal [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2016-03-21

    X-ray dark-field contrast tomography can provide important supplementary information inside a sample to the conventional absorption tomography. Recently, the X-ray speckle based technique has been proposed to provide qualitative two-dimensional dark-field imaging with a simple experimental arrangement. In this letter, we deduce a relationship between the second moment of scattering angle distribution and cross-correlation degradation of speckle and establish a quantitative basis of X-ray dark-field tomography using single directional speckle scanning technique. In addition, the phase contrast images can be simultaneously retrieved permitting tomographic reconstruction, which yields enhanced contrast in weakly absorbing materials. Such complementary tomography technique can allow systematic investigation of complex samples containing both soft and hard materials.

  9. Scanning transmission proton microscopy tomography of reconstruction cells from simulated data

    International Nuclear Information System (INIS)

    Zhang Conghua; Li Min; Hou Qing

    2011-01-01

    For scanning transmission proton microscopy tomography, to compare cell images of the proton stopping power and relative electron density, two cell phantoms are designed and simulated by code FLUKA. The cell images are reconstructed by the filtered back projection algorithm, and compared with their tomography imaging. The images of stopping power and relative electron density slightly vary with proton energies, but the internal images are of clear with high resolution. The organic glass image of relative electron density reveals the resolution power of proton tomography. Also, the simulation results reflect effects of the boundary enhancement, the weak artifacts, and the internal structure border extension by multiple scattering. So using proton tomography to analyze internal structure of a cell is a superior. (authors)

  10. A study using computerized tomography in the clinical practice of temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yamamoto, Kunimitsu

    1982-01-01

    The author has studied about analysis of clinical data and CT findings examined conventional method for 50 cases of temporal lobe epilepsy and how to assess the foci of temporal lobe by CT. According to the examination of conventional neuroradiologic technique and routine work of CT for temporal lobe epilepsy, an extreme space occuping lesions were detected and marked cerebral atrophy, low density area in temporal lobe were found out, but, most of them were not able to detect foci of the temporal lobe and yet, the study of CT number based on the print out data did not give any precise informations about epileptogenic lesions of temporal lobe epilepsy. The method of reversed axial section CT was designed to photograph inferior horn of lateral ventricles with the purpose to delineate the hippocampus and amygdata, and precise pictures from autopsy brain and clinical cases were obtained by that method about scanning angle of reversed axial section CT, various angles are made an experiment on scanning, such as reversed 15 0 , 20 0 , 25 0 , 30 0 , 35 0 . Among them, it is proved that the reversed angle of almost 25 0 is most suitable to delineate mesial temporal structure, so as to say, foci of the temporal lobe. (J.P.N.)

  11. 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.)

  12. 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

  13. 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

  14. 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

  15. Clinical observations of infants with multiple encephalomalacia on cranial computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Eda, I.; Yoshino, K.; Nakai, M.; Takashima, S. (Tottori Univ., Yonago (Japan). School of Medicine); Morita, M.

    1982-09-01

    Four cases whose CT scans showed multi-focal or diffuse low density in both cerebral hemisphere were reported and their clinical histories, roentogenographic and electroencephalographic findings were compared. Out of 2 cases with multi-focal low density, one fatal case (Case 1) was diagnosed neuropathologically as multicystic encephalomalacia (MCEM). He had asphyxia at delivery, convulsion and fever for a few days from the first day. Case 2 was one of twins with a clinical history of intrauterine onset. He had no trouble in delivery but poor feedings in the neonatal period. Two cases showed microcephaly, severe psychomotor retardation and tetraplegia later. Two cases with diffuse low density had the episode of respiratory arrest in early infancy. In one patient (Case 3), several cavities in CT and PEG at 2 months of age were demonstrated, and changed into diffuse low density of cerebral hemispheres at 8 months. Case 4 showed almost normal CT at the age of 16 days and developed diffuse low density at 5 months. They also showed microcephaly, severe psychomotor retardation and tetraplegia. EEG showed irregular slow wave activities in 2 cases with multicystic lesions, and almost flat activities in 2 cases with diffuse cystic lesions. The former was compatible with MCEM and the latter hydranencephaly of postnatal onset described by Friede. It was concluded that diffuse cystic lesion could be classified as an extreme type of MCEM, and both destructive lesions caused by pre-or postnatal hypoxia and circulatory disturbances of different severity. Serial CT scans might demonstrate the onset and progression of these pathological changes. EEG was also useful for monitoring the courses of these diseases.

  16. Clinical observations of infants with multiple encephalomalacia on cranial computerized tomography

    International Nuclear Information System (INIS)

    Eda, Isematsu; Yoshino, Kunio; Nakai, Minako; Takashima, Sachio; Morita, Motoaki.

    1982-01-01

    Four cases whose CT scans showed multi-focal or diffuse low density in both cerebral hemisphere were reported and their clinical histories, roentogenographic and electroencephalographic findings were compared. Out of 2 cases with multi-focal low density, one fatal case (Case 1) was diagnosed neuropathologically as multicystic encephalomalacia (MCEM). He had asphyxia at delivery, convulsion and fever for a few days from the first day. Case 2 was one of twins with a clinical history of intrauterine onset. He had no trouble in delivery but poor feedings in the neonatal period. Two cases showed microcephaly, severe psychomotor retardation and tetraplegia later. Two cases with diffuse low density had the episode of respiratory arrest in early infancy. In one patient (Case 3), several cavities in CT and PEG at 2 months of age were demonstrated, and changed into diffuse low density of cerebral hemispheres at 8 months. Case 4 showed almost normal CT at the ag e of 16 days and developed diffuse low density at 5 months. They also showed microcephaly, severe psychomotor retardation and tetraplegia. EEG showed irregular slow wave activities in 2 cases with multicystic lesions, and almost flat activities in 2 cases with diffuse cystic lesions. The former was compatible with MCEM and the latter hydranencephaly of postnatal onset described by Friede. It was concluded that diffuse cystic lesion could be classified as an extreme type of MCEM, and both destructive lesions caused by pre-or postnatal hypoxia and circulatory disturbances of different severity. Serial CT scans might demonstrate the onset and progression of these pathological changes. EEG was also useful for monitoring the courses of these diseases. (author)

  17. 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.)

  18. 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.

  19. 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

  20. 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)

  1. 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)

  2. 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

  3. 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)

  4. 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.

  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. The computerized tomography as a new method for studing the physics of water in soil

    International Nuclear Information System (INIS)

    Crestana, S.

    1985-08-01

    In this thesis we present a new method for the investigation of water in Soil Physics using X-ray Computed Tomographic scanning. We show that the new method is in agreement with previous classical techniques such as γ-ray attenuation and gravimetric. We also demonstrate that the method allows new approaches quantitative analysis of problems such as bi and tridimensional dynamical studies as well as of heterogeneity in soil and water distributions. We apply the method to investigations of vertical infiltration of water in wet and compacted soil, simulation of drop irrigation and for preliminary studies of seed germination 'in situ'. These applicatons would not not be possible without these capabilities and advantages of this new method. Our results complement those of Perovic et al and Hainsworth et al in that we have investigated experimentally the complete dependence of H. U. (Hounsfield Units) on dry bulk density, water content and energy. Finally we also repeat some of our results obtained, using a non-medical X and γ-ray minitomograph of considerable simplicity wich will open new possibilities for the application of the proposed method. (Author) [pt

  7. Improving limited-projection-angle fluorescence molecular tomography using a co-registered x-ray computed tomography scan.

    Science.gov (United States)

    Radrich, Karin; Ale, Angelique; Ermolayev, Vladimir; Ntziachristos, Vasilis

    2012-12-01

    We examine the improvement in imaging performance, such as axial resolution and signal localization, when employing limited-projection-angle fluorescence molecular tomography (FMT) together with x-ray computed tomography (XCT) measurements versus stand-alone FMT. For this purpose, we employed living mice, bearing a spontaneous lung tumor model, and imaged them with FMT and XCT under identical geometrical conditions using fluorescent probes for cancer targeting. The XCT data was employed, herein, as structural prior information to guide the FMT reconstruction. Gold standard images were provided by fluorescence images of mouse cryoslices, providing the ground truth in fluorescence bio-distribution. Upon comparison of FMT images versus images reconstructed using hybrid FMT and XCT data, we demonstrate marked improvements in image accuracy. This work relates to currently disseminated FMT systems, using limited projection scans, and can be employed to enhance their performance.

  8. 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)

  9. 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

  10. 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

  11. 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)

  12. 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)

  13. Volume adjustment of lung density by computed tomography scans in patients with emphysema

    DEFF Research Database (Denmark)

    Shaker, S B; Dirksen, A; Laursen, Lars Christian

    2004-01-01

    of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within-subject variation in TLV was explored by plotting TLV against PD and RA. RESULTS: The coefficients for volume adjustment for PD were...... relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. CONCLUSION: Volume adjustment is mandatory in repeated CT densitometry......PURPOSE: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. MATERIAL AND METHODS: Fifty patients with emphysema underwent 3 CT scans at 2-week intervals. The scans were analyzed with a software...

  14. Introduction of helical computed tomography affects patient selection for V/Q lung scan

    International Nuclear Information System (INIS)

    Zettinig, G.; Baudrexel, S.; Leitha, Th.

    2002-01-01

    Aim: Retrospective analysis for determination of the effect of helical computed tomography (HCT) on utilization of V/Q lung scanning to diagnose pulmonary embolism (PE) in a large general hospital. Methods: A total number of 2676 V/Q scans of in- and out-patients referred to our department between March 1992 and December 1998 and between April 1997 and December 1998 were analyzed by an identical group of nuclear physicians. Results: Neither the total number of annually performed V/Q scans (446 ± 135) nor the mean age of patients (56 years ± 17) changed significantly since the introduction of HCT. However, the referral pattern was different. The percentage of patients with high and intermediate probability for PE decreased significantly from 15.2% to 9.4% (p <0.01) and from 10.2% to 7.3% (p <0.05), respectively. Low probability scans significantly increased from 37.8% to 42.7% (p <0.05). The percentage of normal scans did not change significantly, however, there was a highly significant increase summarizing patients with normal and low probability scans (74.6% to 83.3%; p <0.01). Conclusion: The introduction of HCT affected the selection of patients referred for V/Q lung scanning since V/Q scanning was primarily used to exclude rather to confirm PE. (orig.)

  15. An electron beam linear scanning mode for industrial limited-angle nano-computed tomography

    Science.gov (United States)

    Wang, Chengxiang; Zeng, Li; Yu, Wei; Zhang, Lingli; Guo, Yumeng; Gong, Changcheng

    2018-01-01

    Nano-computed tomography (nano-CT), which utilizes X-rays to research the inner structure of some small objects and has been widely utilized in biomedical research, electronic technology, geology, material sciences, etc., is a high spatial resolution and non-destructive research technique. A traditional nano-CT scanning model with a very high mechanical precision and stability of object manipulator, which is difficult to reach when the scanned object is continuously rotated, is required for high resolution imaging. To reduce the scanning time and attain a stable and high resolution imaging in industrial non-destructive testing, we study an electron beam linear scanning mode of nano-CT system that can avoid mechanical vibration and object movement caused by the continuously rotated object. Furthermore, to further save the scanning time and study how small the scanning range could be considered with acceptable spatial resolution, an alternating iterative algorithm based on ℓ0 minimization is utilized to limited-angle nano-CT reconstruction problem with the electron beam linear scanning mode. The experimental results confirm the feasibility of the electron beam linear scanning mode of nano-CT system.

  16. Extensive Tattoos Mimicking Lymphatic Metastasis on Positron Emission Tomography Scan in a Patient With Cervical Cancer.

    Science.gov (United States)

    Grove, Narine; Zheng, Ma; Bristow, Robert E; Eskander, Ramez N

    2015-07-01

    Positron emission tomography (PET) fused with computed tomography (CT) imaging is common in the clinical assessment of patients with locally advanced cervical cancer. Limitations to the utilization and interpretation of PET-CT scans in patients with cervical cancer have been described, including false-positive findings secondary to tattoo ink. A 32-year-old woman presented with clinical stage 1B1 cervical cancer and extensive tattoos of the lower extremities. Preoperative PET-CT scan identified two ileac lymph nodes with increased fluorine-18-deoxyglucose uptake suspicious for metastatic disease. At the time of surgical resection, bilateral pigmented lymph nodes were identified with histologic examination showing deposition of tattoo ink and no malignant cells. Physicians should be cognizant of the possible effects of tattoos on PET-CT findings while counseling patients and formulating a treatment program.

  17. Evaluation of cleft lip and palate by computed tomography with 2 mm thin slice scanning

    International Nuclear Information System (INIS)

    Tanaka, Hiroshi

    1988-01-01

    Computed tomography was carried out in 65 patients of cleft lip and palate with continuous 2 mm slice scanning. The cleft lip and palate was classified by shape of the hard palate as normal, hypoplasia, and aplasia, depending on its developmental degree. The shape of alveolus was also grouped as circular, triangular, and asymmetric forms for the evaluation of maxillar development. The hard palatal development well correlated with the shape of the alveolus. Frequency of sinusitis and mastoiditis increased with the severity of hard palatal malformation. Evaluation of the hard palate by thin slice scanning is usefull standpoint of presumption of future maxillary development. (author)

  18. Evaluation of cleft lip and palate by computed tomography with 2 mm thin slice scanning, 2

    International Nuclear Information System (INIS)

    Uchiyama, Mayuki; Tanaka, Hiroshi; Harada, Junta

    1992-01-01

    Computed tomography was performed on 104 patients with cleft lip and palate by continuous 2 mm slice scanning. The type of hard palate was classified as normal, hypoplasia and aplasia, depending on its developmental degree. The shape of alveolus was also classified as circular, triangular and asymmetric forms for the evaluation of the maxillary development. The hard palate development correlated with the shape of the alveolus, the diameter of maxillary and mandibular bone, and frequency of sinusitis and otitis media. Evaluation of the hard palate by thin slice scanning is useful in presumption of future fecial development. (author)

  19. Evaluation of cleft lip and palate by computed tomography with 2 mm thin slice scanning

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hiroshi

    1988-07-01

    Computed tomography was carried out in 65 patients of cleft lip and palate with continuous 2 mm slice scanning. The cleft lip and palate was classified by shape of the hard palate as normal, hypoplasia, and aplasia, depending on its developmental degree. The shape of alveolus was also grouped as circular, triangular, and asymmetric forms for the evaluation of maxillar development. The hard palatal development well correlated with the shape of the alveolus. Frequency of sinusitis and mastoiditis increased with the severity of hard palatal malformation. Evaluation of the hard palate by thin slice scanning is usefull standpoint of presumption of future maxillary development.

  20. Evaluation of cleft lip and palate by computed tomography with 2 mm thin slice scanning, 2

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Mayuki; Tanaka, Hiroshi; Harada, Junta (Jikei Univ., Tokyo (Japan). School of Medicine)

    1992-06-01

    Computed tomography was performed on 104 patients with cleft lip and palate by continuous 2 mm slice scanning. The type of hard palate was classified as normal, hypoplasia and aplasia, depending on its developmental degree. The shape of alveolus was also classified as circular, triangular and asymmetric forms for the evaluation of the maxillary development. The hard palate development correlated with the shape of the alveolus, the diameter of maxillary and mandibular bone, and frequency of sinusitis and otitis media. Evaluation of the hard palate by thin slice scanning is useful in presumption of future fecial development. (author).

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  2. Differential phase microscope and micro-tomography with a Foucault knife-edge scanning filter

    Science.gov (United States)

    Watanabe, N.; Hashizume, J.; Goto, M.; Yamaguchi, M.; Tsujimura, T.; Aoki, S.

    2013-10-01

    An x-ray differential phase microscope with a Foucault knife-edge scanning filter was set up at the bending magnet source BL3C, Photon Factory. A reconstructed phase profile from the differential phase image of an aluminium wire at 5.36 keV was fairly good agreement with the numerical simulation. Phase tomography of a biological specimen, such as an Artemia cyst, could be successfully demonstrated.

  3. Scanning transmission ion micro-tomography (STIM-T) of biological specimens

    International Nuclear Information System (INIS)

    Schwertner, Michael; Sakellariou, Arthur; Reinert, Tilo; Butz, Tilman

    2006-01-01

    Computed tomography (CT) was applied to sets of Scanning Transmission Ion Microscopy (STIM) projections recorded at the LIPSION ion beam laboratory (Leipzig) in order to visualize the 3D-mass distribution in several specimens. Examples for a test structure (copper grid) and for biological specimens (cartilage cells, cygospore) are shown. Scanning Transmission Micro-Tomography (STIM-T) at a resolution of 260 nm was demonstrated for the first time. Sub-micron features of the Cu-grid specimen were verified by scanning electron microscopy. The ion energy loss measured during a STIM-T experiment is related to the mass density of the specimen. Typically, biological specimens can be analysed without staining. Only shock freezing and freeze-drying is required to preserve the ultra-structure of the specimen. The radiation damage to the specimen during the experiment can be neglected. This is an advantage compared to other techniques like X-ray micro-tomography. At present, the spatial resolution is limited by beam position fluctuations and specimen vibrations

  4. 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.

  5. 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

  6. 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)

  7. Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo

    Science.gov (United States)

    Liang, Kaicheng; Wang, Zhao; Ahsen, Osman O.; Lee, Hsiang-Chieh; Potsaid, Benjamin M.; Jayaraman, Vijaysekhar; Cable, Alex; Mashimo, Hiroshi; Li, Xingde; Fujimoto, James G.

    2018-01-01

    Devices that perform wide field-of-view (FOV) precision optical scanning are important for endoscopic assessment and diagnosis of luminal organ disease such as in gastroenterology. Optical scanning for in vivo endoscopic imaging has traditionally relied on one or more proximal mechanical actuators, limiting scan accuracy and imaging speed. There is a need for rapid and precise two-dimensional (2D) microscanning technologies to enable the translation of benchtop scanning microscopies to in vivo endoscopic imaging. We demonstrate a new cycloid scanner in a tethered capsule for ultrahigh speed, side-viewing optical coherence tomography (OCT) endomicroscopy in vivo. The cycloid capsule incorporates two scanners: a piezoelectrically actuated resonant fiber scanner to perform a precision, small FOV, fast scan and a micromotor scanner to perform a wide FOV, slow scan. Together these scanners distally scan the beam circumferentially in a 2D cycloid pattern, generating an unwrapped 1 mm × 38 mm strip FOV. Sequential strip volumes can be acquired with proximal pullback to image centimeter-long regions. Using ultrahigh speed 1.3 μm wavelength swept-source OCT at a 1.17 MHz axial scan rate, we imaged the human rectum at 3 volumes/s. Each OCT strip volume had 166 × 2322 axial scans with 8.5 μm axial and 30 μm transverse resolution. We further demonstrate OCT angiography at 0.5 volumes/s, producing volumetric images of vasculature. In addition to OCT applications, cycloid scanning promises to enable precision 2D optical scanning for other imaging modalities, including fluorescence confocal and nonlinear microscopy. PMID:29682598

  8. 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

  9. 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.

  10. 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

  11. Clinical Symptoms of Minor Head Trauma and Abnormal Computed Tomography Scan

    Directory of Open Access Journals (Sweden)

    Maghsoudi

    2015-11-01

    Full Text Available Background Minor head trauma accounts for 70% to 90% of all head traumas. Previous studies stated that minor head traumas were associated with 7% - 20% significant abnormal findings in brain computed tomography (CT-scans. Objectives The aim of this study was to reevaluate clinical criteria of taking brain CT scan in patients who suffered from minor head trauma. Patients and Methods We enrolled 680 patients presented to an academic trauma hospital with minor head trauma in a prospective manner. All participants underwent brain CT scan if they met the inclusion criteria and the results of scans were compared with clinical examination finding. Results Loss of consciousness (GCS drop or amnesia was markedly associated with abnormal brain CT scan (P < 0.05. Interestingly, we found 7 patients with normal clinical examination but significant abnormal brain CT scan. Conclusions According to the results of our study, we recommend that all patients with minor head trauma underwent brain CT scan in order not to miss any life-threatening head injuries.

  12. 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

  13. 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.

  14. 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

  15. Optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy in retinal nerve fiber layer measurements of glaucoma patients.

    Science.gov (United States)

    Fanihagh, Farsad; Kremmer, Stephan; Anastassiou, Gerasimos; Schallenberg, Maurice

    2015-01-01

    To determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer (RNFL) of glaucoma patients: optical coherence tomography (OCT), scanning laser polarimetry (SLP) and confocal scanning laser ophthalmoscopy (CSLO). 114 eyes of patients with moderate open angle glaucoma underwent spectral domain OCT (Topcon SD-OCT 2000 and Zeiss Cirrus HD-OCT), SLP (GDx VCC and GDx Pro) and CSLO (Heidelberg Retina Tomograph, HRT 3). Correlation coefficients were calculated between the structural parameters yielded by these examinations. The quantitative relationship between the measured RNFL thickness globally and for the four regions (superior, inferior, nasal, temporal) were evaluated with different regression models for all used imaging systems. The strongest correlation of RNFL measurements was found between devices using the same technology like GDx VCC and GDx Pro as well as Topcon OCT and Cirrus OCT. In glaucoma patients, the strongest associations (R²) were found between RNFL measurements of the two optical coherence tomography devices Topcon OCT and Cirrus OCT (R² = 0.513) and between GDx VCC and GDx Pro (R² = 0.451). The results of the OCTs and GDX Pro also had a strong quantitative relationship (Topcon OCT R² = 0.339 and Cirrus OCT R² = 0.347). GDx VCC and the OCTs showed a mild to moderate association (Topcon OCT R² = 0.207 and Cirrus OCT R² = 0.258). The confocal scanning laser ophthalmoscopy (HRT 3) had the lowest association to all other devices (Topcon OCT R² = 0.254, Cirrus OCT R² = 0.158, GDx Pro R² = 0.086 and GDx VCC R² = 0.1). The measurements of the RNFL in glaucoma patients reveal a high correlation of OCT and GDx devices because OCTs can measure all major retinal layers and SLP can detect nerve fibers allowing a comparison between the results of this devices. However, CSLO by means of HRT topography can only measure height values of the retinal surface but it cannot distinguish

  16. What Can Computed Tomography Scans of the Thorax Show after Breast Surgery?

    Directory of Open Access Journals (Sweden)

    Afsaneh Alikhassi

    2016-06-01

    Full Text Available Background: Postoperative breast abnormalities after breast conserving surgery or modified radical mastectomy are frequently overlooked and inaccurately assessed or reported using multidetector computed tomography (MDCT. These inaccurate results may have legal ramifications for the clinicians, cause patients avoidable anxiety, and lead to additional unnecessary diagnostic follow-up testing and costs.Methods: The patients with a history of breast cancer who had undergone breast-conserving surgery or modified radical mastectomy up to 6 months prior to undergoing a thoracic MDCT scan consented and enrolled in this study. These patients underwent a thoracic MDCT scan either because of respiratory or cardiac clinical symptoms or as part of breast cancer staging.Results: Forty women were included in this study. Different postoperative breast changes observed on thoracic MDCT scans including fibrous scar tissue, fat necrosis, seroma, abscess, hematoma, and recurrent and residual tumor were described.Conclusions: MDCT scans offer sufficient evidence in many postoperative cases to allow a confident diagnosis. General radiologists who review thoracic MDCT scans should know how to characterize breast lesions incidentally found on MDCT scans after breast surgeries. This information would enhance the value of the radiologist’s report for appropriate case management.

  17. Integration of Digital Dental Casts in Cone-Beam Computed Tomography Scans

    Science.gov (United States)

    Rangel, Frits A.; Maal, Thomas J. J.; Bergé, Stefaan J.; Kuijpers-Jagtman, Anne Marie

    2012-01-01

    Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors have described methods to integrate digital dental casts into CBCT scans, but all reported methods have drawbacks. The aim of this feasibility study is to present a new simplified method to integrate digital dental casts into CBCT scans. In a patient scheduled for orthognathic surgery, titanium markers were glued to the gingiva. Next, a CBCT scan and dental impressions were made. During the impression-taking procedure, the titanium markers were transferred to the impression. The impressions were scanned, and all CBCT datasets were exported in DICOM format. The two datasets were matched, and the dentition derived from the scanned impressions was transferred to the CBCT of the patient. After matching the two datasets, the average distance between the corresponding markers was 0.1 mm. This novel method allows for the integration of digital dental casts into CBCT scans, overcoming problems such as unwanted extra radiation exposure, distortion of soft tissues due to the use of bite jigs, and time-consuming digital data handling. PMID:23050159

  18. 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

  19. Handheld ultrahigh speed swept source optical coherence tomography instrument using a MEMS scanning mirror.

    Science.gov (United States)

    Lu, Chen D; Kraus, Martin F; Potsaid, Benjamin; Liu, Jonathan J; Choi, Woojhon; Jayaraman, Vijaysekhar; Cable, Alex E; Hornegger, Joachim; Duker, Jay S; Fujimoto, James G

    2013-12-20

    We developed an ultrahigh speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument using a 2D MEMS mirror. A vertical cavity surface-emitting laser (VCSEL) operating at 1060 nm center wavelength yielded a 350 kHz axial scan rate and 10 µm axial resolution in tissue. The long coherence length of the VCSEL enabled a 3.08 mm imaging range with minimal sensitivity roll-off in tissue. Two different designs with identical optical components were tested to evaluate handheld OCT ergonomics. An iris camera aided in alignment of the OCT beam through the pupil and a manual fixation light selected the imaging region on the retina. Volumetric and high definition scans were obtained from 5 undilated normal subjects. Volumetric OCT data was acquired by scanning the 2.4 mm diameter 2D MEMS mirror sinusoidally in the fast direction and linearly in the orthogonal slow direction. A second volumetric sinusoidal scan was obtained in the orthogonal direction and the two volumes were processed with a software algorithm to generate a merged motion-corrected volume. Motion-corrected standard 6 x 6 mm(2) and wide field 10 x 10 mm(2) volumetric OCT data were generated using two volumetric scans, each obtained in 1.4 seconds. High definition 10 mm and 6 mm B-scans were obtained by averaging and registering 25 B-scans obtained over the same position in 0.57 seconds. One of the advantages of volumetric OCT data is the generation of en face OCT images with arbitrary cross sectional B-scans registered to fundus features. This technology should enable screening applications to identify early retinal disease, before irreversible vision impairment or loss occurs. Handheld OCT technology also promises to enable applications in a wide range of settings outside of the traditional ophthalmology or optometry clinics including pediatrics, intraoperative, primary care, developing countries, and military medicine.

  20. Abdominal fat-evaluation by use of single scan computed tomography

    International Nuclear Information System (INIS)

    Jacobi, V.; Steinkamp, M.; Kirchner, J.; Fischer, H.; Diedrich, C.F.; Kollath, J.

    1997-01-01

    Purpose: Several studies emphasised the importance of the relationship between intraabdominal and total body adipose tissue as a risk factor for the development of metabolic or cardiovascular diseases. Therefore, the aim of the present study was to examine whether a single scan computed tomography is able to determine the whole intraabdominal fat volume with high accuracy and reproducibility. Materials and methods: Regions of interests (ROIs) were drawn manually for measuring intraabdominal fat in 51 unsuspicious abdominal CT. Results: The sexual differentiation of adipose tissue already described in a lot of studies could be confirmed in this study. Fat still predominates in females in lower half of the body (gynoid obesity). In men it predominates in the upper half (android obesity). Significant correlation concerning measuring the whole intraabdominal fat volume could be found in L1-level in women (r=0.992) and in L2-level in men (r=0.992). Measurement of a single scan enables us to assess whole intraabdominal fat volume due to a special formula. Conclusion: The determination of intraabdominal fat measured by a single scan computed tomography is a procedure associated with high accuracy and reproducibility. (orig.) [de

  1. Computed tomography by reconstruction. Brain CT scanning. I. Basic physics, equipment, normal aspects, artefacts

    International Nuclear Information System (INIS)

    Chiras, J.; Palmieri, P.; Saudinos, J.; Salamon, G.

    1980-01-01

    The authors describe the physical basis, apparatus, normal images, and artefacts of computed tomography by reconstruction. Radio-anatomical sections enable clear comprehension of the computed tomography images. Other methods using computer reconstruction are outlined: tomography by Compton effect, tomography by positrons, tomography by gamma emission, tomography by protons, tomography by nuclear magnetic resonance [fr

  2. 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)....

  3. Improving image quality by accounting for changes in water temperature during a photoacoustic tomography scan.

    Directory of Open Access Journals (Sweden)

    Dominique Van de Sompel

    Full Text Available The emerging field of photoacoustic tomography is rapidly evolving with many new system designs and reconstruction algorithms being published. Many systems use water as a coupling medium between the scanned object and the ultrasound transducers. Prior to a scan, the water is heated to body temperature to enable small animal imaging. During the scan, the water heating system of some systems is switched off to minimize the risk of bubble formation, which leads to a gradual decrease in water temperature and hence the speed of sound. In this work, we use a commercially available scanner that follows this procedure, and show that a failure to model intra-scan temperature decreases as small as 1.5°C leads to image artifacts that may be difficult to distinguish from true structures, particularly in complex scenes. We then improve image quality by continuously monitoring the water temperature during the scan and applying variable speed of sound corrections in the image reconstruction algorithm. While upgrading to an air bubble-free heating pump and keeping it running during the scan could also solve the changing temperature problem, we show that a software correction for the temperature changes provides a cost-effective alternative to a hardware upgrade. The efficacy of the software corrections was shown to be consistent across objects of widely varying appearances, namely physical phantoms, ex vivo tissue, and in vivo mouse imaging. To the best of our knowledge, this is the first study to demonstrate the efficacy of modeling temporal variations in the speed of sound during photoacoustic scans, as opposed to spatial variations as focused on by previous studies. Since air bubbles pose a common problem in ultrasonic and photoacoustic imaging systems, our results will be useful to future small animal imaging studies that use scanners with similarly limited heating units.

  4. Estimation of MSAD values in computed tomography scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bruno Beraldo; Teogenes Augusto da, E-mail: bbo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Mourao, Arnaldo Prata [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)

    2013-03-15

    Objective: To evaluate the feasibility of using radiochromic films as an alternative dosimeter to estimate the multiple scan average dose on the basis on kerma profiles. Materials and Methods: The radiochromic films were distributed in cylinders positioned in the center and in four peripheral bores of a standard abdominal phantom utilized for computed tomography dosimetry. Results: Values for multiple scan average dose values corresponded to 13.6 {+-} 0.7, 13.5 {+-} 0.7 and 18.7 {+-} 1.0 mGy for pitch of 0.75, 1.00 and 1.50, respectively. Conclusion: In spite of results showing lower values than the reference level for radiodiagnosis (25 mGy) established by the Brazilian regulations for abdominal studies, it is suggested that there is room to optimize procedures and review the reference level for radiodiagnosis in Brazil. (author)

  5. Comparison of radionuclide scans with computer-assisted tomography in diagnosis of intracranial disease

    International Nuclear Information System (INIS)

    Clifford, J.R.; Connolly, E.S.; Voorhies, R.M.

    1976-01-01

    Radionuclide brain scans were compared with computer-assisted tomography (CAT) for the diagnosis of intracranial disorders in 297 patients. The diagnosis was confirmed in 281 patients who formed the population for the study. The radionuclide scan was false positive for 12 patients (3.9 percent) and false negative for eight (2.6 percent). The CAT was false positive for three patients (1 percent) and false negative for one (0.3 percent). In the 133 patients in whom both tests were negative, no evidence of central nervous system pathology has been found during the 6 to 18 month follow-up. Brain tumors and intracerebral hemorrhage are more readily detectable with CAT

  6. Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study

    DEFF Research Database (Denmark)

    Buchgreitz, J; Buchgreitz, M; Mortensen, D

    2016-01-01

    AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic bloc...

  7. Frequent Computed Tomography Scanning Due to Incomplete Three-View X-Ray Imaging of the Cervical Spine

    NARCIS (Netherlands)

    Saltzherr, Teun Peter; Beenen, Ludo F. M.; Reitsma, Johannes B.; Luitse, Jan S. K.; Vandertop, W. Peter; Goslings, J. Carel

    2010-01-01

    Background: Conventional C-spine imaging (3-view series) is still widely used in trauma patients, although the utilization of computed tomography (CT) scanning is increasing. The aim of this study was to analyze the value of conventional radiography and the frequency of subsequent CT scanning due to

  8. Nano-Tomography of Porous Geological Materials Using Focused Ion Beam-Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-10-01

    Full Text Available Tomographic analysis using focused ion beam-scanning electron microscopy (FIB-SEM provides three-dimensional information about solid materials with a resolution of a few nanometres and thus bridges the gap between X-ray and transmission electron microscopic tomography techniques. This contribution serves as an introduction and overview of FIB-SEM tomography applied to porous materials. Using two different porous Earth materials, a diatomite specimen, and an experimentally produced amorphous silica layer on olivine, we discuss the experimental setup of FIB-SEM tomography. We then focus on image processing procedures, including image alignment, correction, and segmentation to finally result in a three-dimensional, quantified pore network representation of the two example materials. To each image processing step we consider potential issues, such as imaging the back of pore walls, and the generation of image artefacts through the application of processing algorithms. We conclude that there is no single image processing recipe; processing steps need to be decided on a case-by-case study.

  9. Volume Adjustment of Lung Density by Computed Tomography Scans in Patients with Emphysema

    International Nuclear Information System (INIS)

    Shaker, S.B.; Dirksen, A.; Laursen, L.C.; Skovgaard, L.T.; Holstein-Rathlou, N.H.

    2004-01-01

    Purpose: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. Material and Methods: Fifty patients with emphysema underwent 3 CT scans at 2-week intervals. The scans were analyzed with a software package that detected the lung in contiguous images and subsequently generated a histogram of the pixel attenuation values. The total lung volume (TLV), lung weight, percentile density (PD), and relative area of emphysema (RA) were calculated from this histogram. RA and PD are commonly applied measures of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within-subject variation in TLV was explored by plotting TLV against PD and RA. Results: The coefficients for volume adjustment for PD were relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. Conclusion: Volume adjustment is mandatory in repeated CT densitometry and is more robust for PD than for RA. Therefore, PD seems more suitable for monitoring the progression of emphysema

  10. MEMS-based non-rotatory circumferential scanning optical probe for endoscopic optical coherence tomography

    Science.gov (United States)

    Xu, Yingshun; Singh, Janak; Siang, Teo Hui; Ramakrishna, Kotlanka; Premchandran, C. S.; Sheng, Chen Wei; Kuan, Chuah Tong; Chen, Nanguang; Olivo, Malini C.; Sheppard, Colin J. R.

    2007-07-01

    In this paper, we present a non-rotatory circumferential scanning optical probe integrated with a MEMS scanner for in vivo endoscopic optical coherence tomography (OCT). OCT is an emerging optical imaging technique that allows high resolution cross-sectional imaging of tissue microstructure. To extend its usage to endoscopic applications, a miniaturized optical probe based on Microelectromechanical Systems (MEMS) fabrication techniques is currently desired. A 3D electrothermally actuated micromirror realized using micromachining single crystal silicon (SCS) process highlights its very large angular deflection, about 45 degree, with low driving voltage for safety consideration. The micromirror is integrated with a GRIN lens into a waterproof package which is compatible with requirements for minimally invasive endoscopic procedures. To implement circumferential scanning substantially for diagnosis on certain pathological conditions, such as Barret's esophagus, the micromirror is mounted on 90 degree to optical axis of GRIN lens. 4 Bimorph actuators that are connected to the mirror on one end via supporting beams and springs are selected in this micromirror design. When actuators of the micromirror are driven by 4 channels of sinusoidal waveforms with 90 degree phase differences, beam focused by a GRIN is redirected out of the endoscope by 45 degree tilting mirror plate and achieve circumferential scanning pattern. This novel driving method making full use of very large angular deflection capability of our micromirror is totally different from previously developed or developing micromotor-like rotatory MEMS device for circumferential scanning.

  11. Colonoscopy and computerised tomography scan are not sufficient to localise right sided colonic lesions accurately.

    LENUS (Irish Health Repository)

    Solon, Jacqueline Gemma

    2009-11-23

    : Aim: accurate pre-operative localisation of colonic lesions is critical especially in laparoscopic colectomy where tactile localisation is absent particularly in screen-detected tumours. The study aimed to evaluate the accuracy of colonoscopy and double-contrast computerised tomography (CT) to localise lesions treated by right hemicolectomy. Method: a retrospective chart review was performed of patients treated by right hemicolectomy under the colorectal service between July 2003 and October 2006. Pre-operative tumour location determined by CT scan and colonoscopy were compared with the intra-operative and histopathologic findings. Results: of 101 patients, 73 (73%) were for adenoma or cancer, with a final diagnosis of adenocarcinoma in 59 (59%). Pre-operative localisation was inaccurate in 29% of lesions using both CT and colonoscopy. In the transverse colon colonoscopy alone was only 37.5% accurate, increasing to 62.5% when information from the CT scan was added. Conclusion: pre-operative localisation of right-sided colon cancers using colonoscopy and CT scanning is unreliable in at least 29% of cases. Inaccurate localisation of transverse colon tumours risks inadequate lymphadenectomy with an adverse cancer outcome. Pre-operative abdominal CT scan improves accuracy but endoscopic tattoo localisation should be employed routinely especially in patients undergoing laparoscopic resection.

  12. Glycosaminoglycan, computed tomography and gallium-67 scanning in malignant pleural mesothelioma

    International Nuclear Information System (INIS)

    Nakano, Takashi; Fujii, Junji; Yamakawa, Kiyohiro; Tamura, Shinsuke; Amuro, Yoshiki; Nabeshima, Kenji; Hada, Toshikazu; Higashino, Kazuya; Horai, Takeshi.

    1985-01-01

    Malignant pleural mesothelioma is an unusual disease, often difficult to diagnose. This paper describes the results of quantitative studies on glycosaminoglycan (GAG) in tumor tissues and the findings of chest computed tomography (CT) and gallium-67 scanning in 5 malignant pleural mesotheliomas. The total amount of GAG in tumor tissue was 2.3 to 17.0 times as high as that in adenocarcinoma of the lung. The amount of hyaluronic acid was 3.5 to 170 times higher than that in adenocarcinoma. Also, the amount of chondroitin sulfate increased 2.6 to 10.0 times, but there were no changes in dermatan sulfate and heparan sulfate contents in this neoplasm when compared with adenocarcinoma. The present study suggests that a marked increase of the total amount of GAG and elevation of either hyaluronic acid and chondroitin sulfate content or both is a characteristic abnormality in this neoplasm. In most cases, CT scan of the chest showed pleural effusion, irregular pleural tumorous thickening surrounding the whole lung surface and extension into the fissure. In 3 cases, tumorous lesions extending into the chest wall at the site of pleural biopsy could be visualized on CT. In the terminal stage, the thoracic cavity was occupied by tumor tissues. Gallium-67 scanning showed a diffusely increased radionuclide accumulation over the involved hemithorax with or without particular intensity in the periphery. Conversely, identification of these characteristic findings of CT and gallium-67 scanning indicates the possibility of malignant pleural mesothelioma. (author)

  13. Subclinical coronary atherosclerosis by multi-scan axial tomography and its association with hyperglycemia

    International Nuclear Information System (INIS)

    Buchaca Faxas, Emilio F; Bencomo Rodriguez, Llimia; Bermudez Rojas, Sergio

    2010-01-01

    A study was conducted to assess the usefulness of multi-scan axial tomography techniques to detect, in a subclinical stage, the coronary damage in patients presenting with diabetes mellitus (DM) to describe the frequency of asymptomatic atherosclerotic affection and its potential association with the fasting and postprandial hyperglycemia. In study were included 59 patients with type 2 diabetes to compare the results of coronary calcium determination with the findings of angiography by multi-scan axial computed tomography (CAT-M). There was a concordance of a 44.1% between both studies, as well as a predominance of soft plaques in the 55.9 % of patients. The 42.4 % showed a narrowing of arterial lumen, which was significant in the 16.5 % of total. A high figure of patients with hyperglycemia had coronary damage compared to those ills with a good glycemia control (p = 0.024). This relation was more evident with the postprandial hyperglycemia (= 0.016). Hyperglycemia had a high opportunity (5.99 times) to detect coronary lesions by TAC-C compared to other major atherosclerosis risk factors like the high blood pressure, smoking, dyslipemias expressed in a significant way (p 0.045). We conclude that Angio TAC-C and Calcio Score techniques are useful to detect lesions of coronary arteries in patients with type 2 diabetes mellitus without symptoms of myocardial ischemia, which was associated to presence of a hyperglycemia, fundamentally postprandial

  14. Application of X-ray scanning and tomography to evaluate the filtercake removal efficiency

    International Nuclear Information System (INIS)

    Lopes, R.T.; Oliveira, L.F. de; Miranda, C.R.; Leite, J.C.

    2004-01-01

    The removal of the filtercake formed during the drilling operation is essential for a successful cementing job. Nowadays, the use of synthetic base fluids brings the necessity of proceeding new evaluations of the efficiency of the washes in removing the filtercake and to guarantee the wettability inversion of the formation from oil to waterwet. It is presented here the application of X-ray tomographic scanning to evaluate the filtercake removal efficiency performed by different washes. This technique uses a natural core with a perforation, where a filtercake is formed by circulating a drilling fluid. The wash is circulated through this perforation and the filtercake removal efficiency is measured precisely by computer tomography scanning. This procedure enables the filtercake removal visualization during the wash circulation through the formation and from the data obtained from the X-ray tomography it is possible to select the most appropriate wash for a given drilling fluid, as well as to predict the necessary contact time between the wash and the formation to achieve an appropriate filtercake removal

  15. Investigation of optimal scanning protocol for X-ray computed tomography polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sellakumar, P. [Bangalore Institute of Oncology, 44-45/2, II Cross, RRMR Extension, Bangalore 560 027 (India)], E-mail: psellakumar@rediffmail.com; James Jebaseelan Samuel, E. [School of Science and Humanities, VIT University, Vellore 632 014 (India); Supe, Sanjay S. [Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Hosur Road, Bangalore 560 027 (India)

    2007-11-15

    X-ray computed tomography is one of the potential tool used to evaluate the polymer gel dosimeters in three dimensions. The purpose of this study is to investigate the factors which affect the image noise for X-ray CT polymer gel dosimetry. A cylindrical water filled phantom was imaged with single slice Siemens Somatom Emotion CT scanner. The imaging parameters like tube voltage, tube current, slice scan time, slice thickness and reconstruction algorithm were varied independently to study the dependence of noise on each other. Reductions of noise with number of images to be averaged and spatial uniformity of the image were also investigated. Normoxic polymer gel PAGAT was manufactured and irradiated using Siemens Primus linear accelerator. The radiation induced change in CT number was evaluated using X-ray CT scanner. From this study it is clear that image noise is reduced with increase in tube voltage, tube current, slice scan time, slice thickness and also reduced with increasing the number of images averaged. However to reduce the tube load and total scan time, it was concluded that tube voltage of 130 kV, tube current of 200 mA, scan time of 1.5 s, slice thickness of 3 mm for high dose gradient and 5 mm for low dose gradient were optimal scanning protocols for this scanner. Optimum number of images to be averaged was concluded to be 25 for X-ray CT polymer gel dosimetry. Choice of reconstruction algorithm was also critical. From the study it is also clear that CT number increase with imaging tube voltage and shows the energy dependency of polymer gel dosimeter. Hence for evaluation of polymer gel dosimeters with X-ray CT scanner needs the optimization of scanning protocols to reduce the image noise.

  16. Lens thickness assessment: anterior segment optical coherence tomography versus A-scan ultrasonography

    Directory of Open Access Journals (Sweden)

    Nikoo Hamzeh

    2015-12-01

    Full Text Available AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT in comparison with A-scan ultrasonography (A-scan US. METHODS: There were 218 adult subjects (218 eyes aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III. Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA. The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74. Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001, and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001 CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

  17. Feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in lung cancer treatment planning

    International Nuclear Information System (INIS)

    Xiao Jianghong; Zhang Hong; Gong Youling; Fu Yuchuan; Tang Bin; Wang Shichao; Jiang Qingfeng; Li Ping

    2010-01-01

    Background and purpose: To investigate the feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in 3-dimensional conformal radiotherapy (3D-CRT), stereotactic body radiation therapy (SBRT) and intensity-modulated radiotherapy (IMRT) treatment planning for lung cancers, respectively. Materials and methods: Twelve patients with bulky lung tumors and 14 patients with small lung tumors were retrospectively analyzed. Each patient took two sets of CT in the same position with active breathing control (ABC) technique before and after intravenous contrast agent (CA) injections. Bulky tumors were planned with 3D-CRT, while SBRT plans were generated for patients with small tumors based on CT scans with intravenous CA. In addition, IMRT plans were generated for patients with bulky tumors to continue on a planning study. All plans were copied and replaced on the scans without intravenous CA. The radiation doses calculated from the two sets of CTs were compared with regard to planning volumes (PTV), the organ at-risk (OAR) and the lungs using Wilcoxon's signed rank test. Results: In comparisons for 3D-CRT plans, CT scans with intravenous CA reduced the mean dose and the maximum dose of PTV with significant differences (p 95 ) for targets, respectively (p < 0.05). There was no statistical significance for lung parameters between two sets of scans in SBRT plans and IMRT plans. Conclusions: The enhanced CT scans can be used for both target delineation and treatment planning in 3D-CRT. The dose difference caused by intravenous CA is small. But for SBRT and IMRT, the minimum irradiation dose in targets may be estimated to be increased up to 2.71% while the maximum dose may be estimated to be decreased up to 1.36%. However, the difference in dose distribution in most cases were found to be clinical tolerable.

  18. Targeted computerised tomography scanning of the ankle syndesmosis with low dose radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kotwal, Rahul [Princess of Wales Hospital, Bridgend (United Kingdom); Rath, Narendra [Royal Gwent Hospital, Newport (United Kingdom); Paringe, Vishal; Hemmadi, Sandeep; Thomas, Rhys; Lyons, Kath [University Hospital of Wales, Cardiff (United Kingdom)

    2016-03-15

    To devise a new protocol for targeted CT scanning of the distal tibiofibular syndesmosis with minimal radiation exposure to patients. We also aimed to correlate the reduction of the syndesmosis as seen on CT scans with the functional outcome of patients. Prospective study. Forty adults undergoing surgical stabilisation of an acute distal tibiofibular syndesmosis injury were recruited. A targeted five-cut computerised tomography scan protocol was developed. The radiation exposure to the patient with this protocol was only 0.002 mSv. Scans were performed 12 weeks after surgery. The contralateral ankle of every patient was used as a control to determine the accuracy of the reduction of the syndesmosis for that individual patient. American Orthopaedic Foot and Ankle Society (AOFAS) scores were obtained at a minimum of 1 year after surgery. After considering the exclusions, 36 patients formed the study group. A wide variation was observed in the anatomy of the normal syndesmosis. If we considered a difference of more than 2 mm between the normal and injured syndesmosis relationship as significant, 15 (41.6 %) of our patients had a significant difference between the injured and normal sides. AOFAS scores were available for 13 of these patients and were good to excellent in 11(84.6 %). Our study describes a reliable new CT scanning technique for the distal tibiofibular syndesmosis using only five cuts and a low-radiation-dose protocol. Clinical correlation of the findings on the scan with functional outcomes suggests that routine post-operative CT of the syndesmosis is probably not justified. (orig.)

  19. Targeted computerised tomography scanning of the ankle syndesmosis with low dose radiation exposure

    International Nuclear Information System (INIS)

    Kotwal, Rahul; Rath, Narendra; Paringe, Vishal; Hemmadi, Sandeep; Thomas, Rhys; Lyons, Kath

    2016-01-01

    To devise a new protocol for targeted CT scanning of the distal tibiofibular syndesmosis with minimal radiation exposure to patients. We also aimed to correlate the reduction of the syndesmosis as seen on CT scans with the functional outcome of patients. Prospective study. Forty adults undergoing surgical stabilisation of an acute distal tibiofibular syndesmosis injury were recruited. A targeted five-cut computerised tomography scan protocol was developed. The radiation exposure to the patient with this protocol was only 0.002 mSv. Scans were performed 12 weeks after surgery. The contralateral ankle of every patient was used as a control to determine the accuracy of the reduction of the syndesmosis for that individual patient. American Orthopaedic Foot and Ankle Society (AOFAS) scores were obtained at a minimum of 1 year after surgery. After considering the exclusions, 36 patients formed the study group. A wide variation was observed in the anatomy of the normal syndesmosis. If we considered a difference of more than 2 mm between the normal and injured syndesmosis relationship as significant, 15 (41.6 %) of our patients had a significant difference between the injured and normal sides. AOFAS scores were available for 13 of these patients and were good to excellent in 11(84.6 %). Our study describes a reliable new CT scanning technique for the distal tibiofibular syndesmosis using only five cuts and a low-radiation-dose protocol. Clinical correlation of the findings on the scan with functional outcomes suggests that routine post-operative CT of the syndesmosis is probably not justified. (orig.)

  20. Low-dose computed tomography image restoration using previous normal-dose scan

    International Nuclear Information System (INIS)

    Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2011-01-01

    Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use