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)

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.)

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

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)

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

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

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

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.)

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

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)

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.

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

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.

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

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)

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

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

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

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

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).

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.

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.

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)

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

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

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)

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.)

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

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Principles of medical imaging with emphasis on tomography

Energy Technology Data Exchange (ETDEWEB)

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

1994-12-31

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

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

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.

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...

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)

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

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

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.)

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)

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

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)

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)

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

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

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

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)

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

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

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

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)

Transformations and algorithms in a computerized brain atlas

International Nuclear Information System (INIS)

Thurfjell, L.; Bohm, C.; Eriksson, L.; Karolinska Institute/Hospital, Stockholm

1993-01-01

The computerized brain atlas constructed at the Karolinska Hospital, Stockholm, Sweden, has been further developed. This atlas was designed to be employed in different fields of neuro imaging such as positron emission tomography (PET), single photon emission tomography (SPECT), computerized tomography (CT) and magnetic resonance imaging (MR). The main objectives with the atlas is to aid the interpretation of functional images by introducing anatomical information, to serve as a tool in the merging of data from different imaging modalities and to facilitate the comparisons of data from different individuals by allowing for anatomical standardization of individual data. The purpose of this paper is to describe the algorithms and transformations used in the implementation of the atlas software

Diagnostic value of sectional images obtained by emission tomography

International Nuclear Information System (INIS)

Roucayrol, J.C.

1981-01-01

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

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.

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.

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)

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 ...

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)

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

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.)

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)

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.

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.)

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.

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

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

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

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

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.

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

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.)

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

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.

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)

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

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.

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

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)

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.).

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%

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)/

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)

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

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.

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...

Image reconstruction. Application to transverse axial tomography

International Nuclear Information System (INIS)

Aubry, Florent.

1977-09-01

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

Positron emission tomography with Positome, 2

International Nuclear Information System (INIS)

Nukui, Hideaki; Yamamoto, Y.L.; Thompson, C.J.; Feindel, W.

1979-01-01

Positron emission tomography with Positome II using 68 Ga-EDTA was performed in cases with brain tumor and cerebral arteriovenous malformation. A significant focal uptake in static study and hemodynamic changes in dynamic study were noted in all cases except one case with intracranial lipoma. Comparing this method with sup(99m) Tc-pertechnetate cerebral image study and computerized axial tomography, the diagnostic rate for detecting brain tumor was almost equal in all of these three methods. However, detecting and localizing was easier and clearer in static positron emission tomography with 68 Ga-EDTA than in sup(99m) Tc-pertechnetate cerebral image and computerized axial tomography without infusion of contrast medium. Furthermore, static positron emission tomography with 68 Ga-EDTA was superior to computerized axial tomography without infusion of contrast medium for detecting cerebral arteriovenous malformation. Concerning dynamic positron emission tomography with 68 Ga-EDTA, semiquantitative values obtained by this method correlated well with findings of computerized axial tomography and was thought to be more precise and in detail than the findings of sup(99m) Tc-pertechnetate cerebral image study. Summation of the previous studies about dynamic positron emission tomography with 77 Kr in occlusive cerebrovascular disease is also reported. In conclusion, static positron emission tomography with 68 Ga-EDTA is a very useful diagnostic method for detecting and localizing brain tumor and cerebral arteriovenous malformation without any attendant complications. Furthermore, a good combination of static and dynamic positron emission tomography and computerized axial tomography appear to be outstandingly effective for not only detecting the lesion but also understanding the pathophysiological aspect in cases with various intracranial lesions. (author)

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)

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.

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

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.

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)

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

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)

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

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.

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.

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.

Computerized tomographic in non-destructive testing

International Nuclear Information System (INIS)

Lopes, R.T.

1988-01-01

The process of computerized tomography has been developed for medical imaging purposes using tomographs with X-ray, and little attention has been given to others possibles applications of technique, because of its cost. As an alternative for the problem, we constructed a Tomographic System (STAC-1), using gamma-rays, for nonmedical applications. In this work we summarize the basic theory of reconstructing images using computerized tomography and we describe the considerations leading to the development of the experimental system. The method of reconstruction image implanted in the system is the filtered backprojection or convolution, with a digital filters system to carried on a pre-filtering in the projections. The experimental system is described, with details of control and the data processing. An alternative and a complementary system, using film as a detector is shown in preliminary form . This thesis discuss and shows the theorical and practical aspects, considered in the construction of the STAC-1, and also its limitations and apllications [pt

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-12-15

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

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

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)

'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

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.)

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

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)

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

OpenAIRE

McCarthy, K. J

1989-01-01

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

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.)

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

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.

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

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

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)

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

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

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

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.

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

Computed Tomography Imaging of the Topographical Anatomy of Canine Prostate

International Nuclear Information System (INIS)

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

2010-01-01

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

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.

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

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

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

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.

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 ...

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

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

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1999-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1998-12-31

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

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

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.)

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)

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

Computerized analysis of brain perfusion parameter images

International Nuclear Information System (INIS)

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

2007-01-01

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

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.

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)

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.)

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

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

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

Positron transaxial emission tomograph with computerized image reconstruction

International Nuclear Information System (INIS)

Jatteau, Michel.

1981-01-01

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

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)

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)

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.

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

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...

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.

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

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.

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

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.)

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

Computed tomography for radiographers

International Nuclear Information System (INIS)

Brooker, M.J.

1986-01-01

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

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.

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

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.

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.

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.

An industrial demonstration of computer assisted tomography

International Nuclear Information System (INIS)

Lupton, L.R.

1985-09-01

Computerized tomography (CT) is a nondestructive testing technique for generating quantitative density (linear attenuation coefficient) maps of a cross section through an object. By using a series of parallel tomographic images taken at different elevations, a three-dimensional (3-D) map of the object can be obtained. To demonstrate the power of tomography, a 3-D region of a motorcycle carburetor has been imaged using twenty-four parallel two-dimensional images. From these data, new images in planes orthogonal to the original planes have been generated, thereby improving the user's ability to visualize the position of components within the carburetor. The data have also been used to demonstrate the relationship between tomography and radiography

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

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

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)

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

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)

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.

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

Pocket book on setting techniques for medical imaging. X-ray diagnostics, angiography, CT, MRT. 4. rev. and enl. ed.; Taschenatlas Einstelltechnik. Roentgendiagnostik, Angiografie, CT, MRT

Energy Technology Data Exchange (ETDEWEB)

Moeller, Torsten B.; Reif, Emil [Caritas-Krankenhaus, Dillingen/Saar (Germany)

2009-07-01

The pocketbook on setting techniques for medical imaging is concerned with the problem to prepare appropriate images for diagnostic purposes using modern high-technology instruments like x-ray diagnostics, angiography, computerized tomography and magnetic resonance tomography. The following issues are covered: Head, spinal column, upper extremities, lower extremities, thorax, gastrointestinal tract, intravenous organ examination, angiography, computerized tomography, NMR imaging.

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.

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.

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)

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

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.

Evaluation of imaging protocol for ECT based on CS image reconstruction algorithm

International Nuclear Information System (INIS)

Zhou Xiaolin; Yun Mingkai; Cao Xuexiang; Liu Shuangquan; Wang Lu; Huang Xianchao; Wei Long

2014-01-01

Single-photon emission computerized tomography and positron emission tomography are essential medical imaging tools, for which the sampling angle number and scan time should be carefully chosen to give a good compromise between image quality and radiopharmaceutical dose. In this study, the image quality of different acquisition protocols was evaluated via varied angle number and count number per angle with Monte Carlo simulation data. It was shown that, when similar imaging counts were used, the factor of acquisition counts was more important than that of the sampling number in emission computerized tomography. To further reduce the activity requirement and the scan duration, an iterative image reconstruction algorithm for limited-view and low-dose tomography based on compressed sensing theory has been developed. The total variation regulation was added to the reconstruction process to improve the signal to noise Ratio and reduce artifacts caused by the limited angle sampling. Maximization of the maximum likelihood of the estimated image and the measured data and minimization of the total variation of the image are alternatively implemented. By using this advanced algorithm, the reconstruction process is able to achieve image quality matching or exceed that of normal scans with only half of the injection radiopharmaceutical dose. (authors)

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

International Nuclear Information System (INIS)

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

1977-01-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-12-31

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

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

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)

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)

Three-dimensional biomedical imaging

International Nuclear Information System (INIS)

Robb, R.A.

1985-01-01

Scientists in biomedical imaging provide researchers, physicians, and academicians with an understanding of the fundamental theories and practical applications of three-dimensional biomedical imaging methodologies. Succinct descriptions of each imaging modality are supported by numerous diagrams and illustrations which clarify important concepts and demonstrate system performance in a variety of applications. Comparison of the different functional attributes, relative advantages and limitations, complementary capabilities, and future directions of three-dimensional biomedical imaging modalities are given. Volume 1: Introductions to Three-Dimensional Biomedical Imaging Photoelectronic-Digital Imaging for Diagnostic Radiology. X-Ray Computed Tomography - Basic Principles. X-Ray Computed Tomography - Implementation and Applications. X-Ray Computed Tomography: Advanced Systems and Applications in Biomedical Research and Diagnosis. Volume II: Single Photon Emission Computed Tomography. Position Emission Tomography (PET). Computerized Ultrasound Tomography. Fundamentals of NMR Imaging. Display of Multi-Dimensional Biomedical Image Information. Summary and Prognostications

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.

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.

Determination of the initial energy in computerized tomography with proton beams; Determinacao da energia inicial em tomografia computadorizada com feixe de protons

Energy Technology Data Exchange (ETDEWEB)

Rocha, Rodrigo Luis da

2007-07-01

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

Development of a computerized tomographic system

International Nuclear Information System (INIS)

Borges, J.C.; Santos, C.A.C.

1986-01-01

The Nuclear Instrumentation Laboratory at COPPE/UFRJ has been developing techniques for detection and applications of nuclear radiations. A lot of research work has been done and resulted in several M.Sc. and D.Sc. thesis, concerning subjects like neutrongraphy, gammagraphy, image reconstruction, special detectors, etc. Recent progress and multiple applications of the computerized tomography to medical and industrial non-destructive tests, pushed the Laboratory to a vast program in this field of research. In this paper, we report what has been done and the results obtained. (Author) [pt

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

International Nuclear Information System (INIS)

Morneburg, H.

1995-01-01

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

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

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

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

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

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

Computed tomography and three-dimensional imaging

International Nuclear Information System (INIS)

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

1987-01-01

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

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

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.

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)

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)

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

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

Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

International Nuclear Information System (INIS)

King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R.

2010-01-01

Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed

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.

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

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)

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

International Nuclear Information System (INIS)

Vrtovec, T.; Likar, B.; Pernuš, F.

2013-01-01

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

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

Medical Imaging with Neural Networks

International Nuclear Information System (INIS)

Pattichis, C.; Cnstantinides, A.

1994-01-01

The objective of this paper is to provide an overview of the recent developments in the use of artificial neural networks in medical imaging. The areas of medical imaging that are covered include : ultrasound, magnetic resonance, nuclear medicine and radiological (including computerized tomography). (authors)

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)

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

DEFF Research Database (Denmark)

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

2001-01-01

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

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)

Vector entropy imaging theory with application to computerized tomography

International Nuclear Information System (INIS)

Wang Yuanmei; Cheng Jianping; Heng, Pheng Ann

2002-01-01

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

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)

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

Nuclear imaging drug development tools

International Nuclear Information System (INIS)

Buchanan, L.; Jurek, P.; Redshaw, R.

2007-01-01

This article describes the development of nuclear imaging as an enabling technology in the pharmaceutical industry. Molecular imaging is maturing into an important tool with expanding applications from validating that a drug reaches the intended target through to market launch of a new drug. Molecular imaging includes anatomical imaging of organs or tissues, computerized tomography (CT), magnetic resonance imaging (MRI) and ultrasound.

Near-Infrared Diffuse Optical Tomography

Directory of Open Access Journals (Sweden)

A. H. Hielscher

2002-01-01

Full Text Available Diffuse optical tomography (DOT is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI or X-ray computerized tomography (CT, DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals.

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

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

Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

Energy Technology Data Exchange (ETDEWEB)

King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R. [Department of Radiology, Committee on Medical Physics, University of Chicago, 5841 South Maryland Avenue, MC 2026, Chicago, Illinois 60637 (United States); Department of Diagnostic Radiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239 (United States); Department of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 5084, Chicago, Illinois 60637 (United States)

2010-11-15

Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed

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.)

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

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

Medical Imaging with Neural Networks

Energy Technology Data Exchange (ETDEWEB)

Pattichis, C [Department of Computer Science, University of Cyprus, Kallipoleos 75, P.O.Box 537, Nicosia (Cyprus); Cnstantinides, A [Department of Electrical Engineering, Imperial College of Science, Technology and Medicine, London SW7 2BT (United Kingdom)

1994-12-31

The objective of this paper is to provide an overview of the recent developments in the use of artificial neural networks in medical imaging. The areas of medical imaging that are covered include : ultrasound, magnetic resonance, nuclear medicine and radiological (including computerized tomography). (authors). 61 refs, 4 tabs.

The use of computed tomography in brain damage testing

International Nuclear Information System (INIS)

De Villiers, J.F.K.

1980-01-01

The article deals with the diagnosis of brain damage by the use of computerized tomography - especially referring to the injuries of boxers. Three conditions may be evaluated with computerized tomography: i) fenestration of the septum pellucidum; ii) cortical atrophy; and, iii) cerebral atrophy. It also appears that computerized tomography has a place in the evaluation of injuries sustained in the ring, as well as the detection of accelerated ageing of the brain or atrophy

Radionuclide and Fluorescence Imaging of Clear Cell Renal Cell Carcinoma Using Dual Labeled Anti-Carbonic Anhydrase IX Antibody G250.

Science.gov (United States)

Muselaers, Constantijn H J; Rijpkema, Mark; Bos, Desirée L; Langenhuijsen, Johan F; Oyen, Wim J G; Mulders, Peter F A; Oosterwijk, Egbert; Boerman, Otto C

2015-08-01

Tumor targeted optical imaging using antibodies labeled with near infrared fluorophores is a sensitive imaging modality that might be used during surgery to assure complete removal of malignant tissue. We evaluated the feasibility of dual modality imaging and image guided surgery with the dual labeled anti-carbonic anhydrase IX antibody preparation (111)In-DTPA-G250-IRDye800CW in mice with intraperitoneal clear cell renal cell carcinoma. BALB/c nu/nu mice with intraperitoneal SK-RC-52 lesions received 10 μg DTPA-G250-IRDye800CW labeled with 15 MBq (111)In or 10 μg of the dual labeled irrelevant control antibody NUH-82 (20 mice each). To evaluate when tumors could be detected, 4 mice per group were imaged weekly during 5 weeks with single photon emission computerized tomography/computerized tomography and the fluorescence imaging followed by ex vivo biodistribution studies. As early as 1 week after tumor cell inoculation single photon emission computerized tomography and fluorescence images showed clear delineation of intraperitoneal clear cell renal cell carcinoma with good concordance between single photon emission computerized tomography/computerized tomography and fluorescence images. The high and specific accumulation of the dual labeled antibody conjugate in tumors was confirmed in the biodistribution studies. Maximum tumor uptake was observed 1 week after inoculation (mean ± SD 58.5% ± 18.7% vs 5.6% ± 2.3% injected dose per gm for DTPA-G250-IRDye800CW vs NUH-82, respectively). High tumor uptake was also observed at other time points. This study demonstrates the feasibility of dual modality imaging with dual labeled antibody (111)In-DTPA-G250-IRDye800CW in a clear cell renal cell carcinoma model. Results indicate that preoperative and intraoperative detection of carbonic anhydrase IX expressing tumors, positive resection margins and metastasis might be feasible with this approach. Copyright © 2015 American Urological Association Education and Research

Interictal "patchy" regional cerebral blood flow patterns in migraine patients. A single photon emission computerized tomographic study

DEFF Research Database (Denmark)

Friberg, L; Olesen, J; Iversen, Helle Klingenberg

1994-01-01

In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right-left asymme......In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right...... rCBF images is insufficient to pick up abnormalities; (2) almost 50% of the migraine sufferers had abnormal rCBF/asymmetries. However, these are discrete compared with those typically seen during the aura phase of a migraine attack. One explanation to the patchy rCBF patterns might...

Photons-based medical imaging - Radiology, X-ray tomography, gamma and positrons tomography, optical imaging; Imagerie medicale a base de photons - Radiologie, tomographie X, tomographie gamma et positons, imagerie optique

Energy Technology Data Exchange (ETDEWEB)

Fanet, H.; Dinten, J.M.; Moy, J.P.; Rinkel, J. [CEA Leti, Grenoble (France); Buvat, I. [IMNC - CNRS, Orsay (France); Da Silva, A. [Institut Fresnel, Marseille (France); Douek, P.; Peyrin, F. [INSA Lyon, Lyon Univ. (France); Frija, G. [Hopital Europeen George Pompidou, Paris (France); Trebossen, R. [CEA-Service hospitalier Frederic Joliot, Orsay (France)

2010-07-01

This book describes the different principles used in medical imaging. The detection aspects, the processing electronics and algorithms are detailed for the different techniques. This first tome analyses the photons-based techniques (X-rays, gamma rays and visible light). Content: 1 - physical background: radiation-matter interaction, consequences on detection and medical imaging; 2 - detectors for medical imaging; 3 - processing of numerical radiography images for quantization; 4 - X-ray tomography; 5 - positrons emission tomography: principles and applications; 6 - mono-photonic imaging; 7 - optical imaging; Index. (J.S.)

Diagnostic imaging to select the candidates to orthotopic transplantation: Experience in a general hospital

International Nuclear Information System (INIS)

Pozzato, Carlo; Baldini, Umberto; Gattoni, Filippo; Raiteri, Riccardo; Lazzerini, Francesco; Uslenghi, Carlo Matteo; Mevoli, Alessandra

1997-01-01

The authors report the experience of our general hospital in selecting the patients for orthotopic liver transplantation (OLT). The accuracy of duplex Doppler and color flow Doppler for portal and/or mesenteric vein thrombosis was evaluated by correlation with resected livers, computerized tomography and angiographic findings. Pathologic examinations diagnosed HCC in 5/20 transplant recipients: 2 lesions were found in 2 resected specimens (total hepatectomy) and 1 lesion was found in 3 cases. The sensitivity of US, plain and dynamic computerized tomography in identifying HCC patients was 20%; US and computerized tomography specificity rates were 100% and 87%, respectively. CTAP sensitivity was 75% and the sensitivity of Lipiodol computerized tomography and angiography was 100%. Therefore, in our series, US was poorly sensitivity in the detection of liver cancers, which may depend on the small number of patients, lesion size and the radiologists ignoring clinical and laboratory data on purpose. Nevertheless, the patients with a single HCC not exceeding 5 cm in diameter or with no more than 3 tumors, none of them exceeding 3 cm in diameter, are generally considered eligible for transplantation: therefore, our patients chosen for OLT on the basis of US and computerized tomography findings were actually eligible for transplantation in spite of US and computerized tomography false negative results. In conclusion, considering also the long stand-by list for OLT, the first selection of transplant candidates could be performed with US and color flow Doppler, plain and dynamic computerized tomography. The patients who are not ruled out as candidates for OLT on the basis of the findings of these imaging techniques and of clinical and laboratory findings are submitted to no further examination and referred to the transplantation unit. Otherwise, if conventional and color flow Doppler US and conventional computerized tomography are not enough to exclude a patient from OLT, the

Brain imaging

International Nuclear Information System (INIS)

Greenfield, L.D.; Bennett, L.R.

1976-01-01

Imaging with radionuclides should be used in a complementary fashion with other neuroradiologic techniques. It is useful in the early detection and evaluation of intracranial neoplasm, cerebrovascular accident and abscess, and in postsurgical follow-up. Cisternography yields useful information about the functional status of cerebrospinal fluid pathways. Computerized axial tomography is a new technique of great promise that produced a cross-sectional image of the brain

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)

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)

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)

Image characterization metrics for muon tomography

Science.gov (United States)

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

2014-05-01

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

NMR imaging of degenerative changes of the spine

International Nuclear Information System (INIS)

Beyer, H.K.

1991-01-01

Computerized tomography and nuclear spin resonance tomography, are today considered excellent ways of demonstrating herniae of intervertebral disks, especially in the lumbal region, at high sensitivity and accuracy. The facility of multiplanar imaging without reconstruction, the clearly greater amount of information by using different pulse sequences, better contrast resolution, and lacking ionizing radiation speak in favour of nuclear spin resonance tomography. Using nulcear spin resonance tomography, in all parts of the spine the excellent demonstration of the epidural space, of the myeloma, of the nerve roots as well as of the surrounding osseous and ligamentous structure is achieved. So, for the diagnosis of discopathies in the region of the cervical spine nuclear spin resonance tomography should be preferred to computerized tomography. In the region of the lumbar spine, however, CT will be of importance in the diagnosis of discopathies for some time. (orig./MG) [de

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

Automated angular and translational tomographic alignment and application to phase-contrast imaging

DEFF Research Database (Denmark)

Cunha Ramos, Tiago Joao; Jørgensen, Jakob Sauer; Andreasen, Jens Wenzel

2017-01-01

X-ray computerized tomography (CT) is a 3D imaging technique that makes use of x-ray illumination and image reconstruction techniques to reproduce the internal cross-sections of a sample. Tomographic projection data usually require an initial relative alignment or knowledge of the exact object po...... improvement in the reconstruction resolution. A MATLAB implementation is made publicly available and will allow robust analysis of large volumes of phase-contrast tomography data.......X-ray computerized tomography (CT) is a 3D imaging technique that makes use of x-ray illumination and image reconstruction techniques to reproduce the internal cross-sections of a sample. Tomographic projection data usually require an initial relative alignment or knowledge of the exact object...... reconstruction artifacts and limit the attained resolution in the final tomographic reconstruction. Alignment algorithms that require manual interaction impede data analysis with ever-increasing data acquisition rates, supplied by more brilliant sources. We present in this paper an iterative reconstruction...

Imaging in hematology. Part 2: Computed tomography, magnetic resonance imaging and nuclear imaging

International Nuclear Information System (INIS)

Zhechev, Y.

2003-01-01

A dramatic increase of the role of imaging in diagnosis of blood diseases occurred with the development of computed tomography (CT) and magnetic resonance imaging (MRI). At present CT of the chest, abdomen, and pelvis is routinely employed in diagnostic and staging evaluation. The bone marrow may be imaged by one of several methods, including scintigraphy, CT and MRI. Nuclear imaging at diagnosis can clarify findings of uncertain significance on conventional staging and may be very useful in the setting of large masses to follow responses to therapy nad to evaluate the residual tumor in a large mass that has responded to treatment. Recent developments such as helical CT, single proton emission computed tomography (SPECT) and positron-emission tomography (PET) have continued to advance diagnosis and therapy

Problems of cranial computer-tomography

Energy Technology Data Exchange (ETDEWEB)

Seitz, D [Allgemeines Krankenhaus St. Georg, Hamburg (Germany, F.R.). Neurologische Abt.

1979-07-01

The author discusses the problems that have cropped up since the introduction of computerized tomography 5 years ago. To begin with, problems of contrast and object resolution are discussed with a special view to the importance of amipague imaging of cisterns, in particular in the detection of basal growing and displacing, intracranial processes. After this, the tasks of computerized tomography in neurological and neurosurgical emergencies, cerebrocranial injuries, cerebral circulation disturbances, inflammatory diseases of the central nervous systems, epileptic seizures, and chronical headaches are reviewed. Special regard is given to the problem of recurrent examinations and course control, especially in cerebral tumours and aresorptive hydrocephalus. Another paragraph deals with the correlation between CT findings, clinical symptoms, and clinical findings. The importance of cranial CT for neurological diagnoses is illustrated by the change of indications for conventional methods of examination. The limits of the method are shown and it is pointed out that cranial CT is not a search technique but that it requires previous examinations by a neurologist, neurosurgeon, or neuropaediatrician.

Problems of cranial computer-tomography

International Nuclear Information System (INIS)

Seitz, D.

1979-01-01

The author discusses the problems that have cropped up since the introduction of computerized tomography 5 years ago. To begin with, problems of contrast and object resolution are discussed with a special view to the importance of amipague imaging of cisterns, in particular in the detection of basal growing and displacing, intracranial processes. After this, the tasks of computerized tomography in neurological and neurosurgical emergencies, cerebrocranial injuries, cerebral circulation disturbances, inflammatory diseases of the central nervous systems, epileptic seizures, and chronical headaches are reviewed. Special regard is given to the problem of recurrent examinations and course control, especially in cerebral tumours and aresorptive hydrocephalus. Another paragraph deals with the correlation between CT findings, clinical symptoms, and clinical findings. The importance of cranial CT for neurological diagnoses is illustrated by the change of indications for conventional methods of examination. The limits of the method are shown and it is pointed out that cranial CT is not a search technique but that it requires previous examinations by a neurologist, neurosurgeon, or neuropaediatrician. (orig.) [de

Effective Heart Disease Detection Based on Quantitative Computerized Traditional Chinese Medicine Using Representation Based Classifiers

Directory of Open Access Journals (Sweden)

Ting Shu

2017-01-01

Full Text Available At present, heart disease is the number one cause of death worldwide. Traditionally, heart disease is commonly detected using blood tests, electrocardiogram, cardiac computerized tomography scan, cardiac magnetic resonance imaging, and so on. However, these traditional diagnostic methods are time consuming and/or invasive. In this paper, we propose an effective noninvasive computerized method based on facial images to quantitatively detect heart disease. Specifically, facial key block color features are extracted from facial images and analyzed using the Probabilistic Collaborative Representation Based Classifier. The idea of facial key block color analysis is founded in Traditional Chinese Medicine. A new dataset consisting of 581 heart disease and 581 healthy samples was experimented by the proposed method. In order to optimize the Probabilistic Collaborative Representation Based Classifier, an analysis of its parameters was performed. According to the experimental results, the proposed method obtains the highest accuracy compared with other classifiers and is proven to be effective at heart disease detection.

Micro-radiography and micro-computerized tomography with absorption and phase contrast for materials characterization; Mikro-Radiografie und Mikro-Computertomografie mit Absorptions- und Phasenkontrast fuer die Materialcharakterisierung

Energy Technology Data Exchange (ETDEWEB)

Kastner, Johann [FH Oberoesterreich, Wels (Austria)

2017-08-01

The contribution describes modern techniques in micro-radiography and micro-computerized tomography for materials characterization using absorption and phase contrast. Using micro- and nano-focus tubes and adequate high.-resolution detectors it is possible to reach resolutions significantly below 1 micron. The CT technology allows in-situ deformation testing to study the damaging mechanism of materials. The application of the Talbot-Lau interferometer with CT a differential phase contrast tomography is available. Dark-field tomography is used to study individual carbon fiber bundles in carbon fiber reinforced laminates.

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

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

Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures

Science.gov (United States)

Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon

2017-02-01

We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

Established rheumatoid arthritis - new imaging modalities

DEFF Research Database (Denmark)

McQueen, Fiona M; Østergaard, Mikkel

2007-01-01

in real-time and facilitates diagnostic and therapeutic interventions such as joint aspiration and injection. Exciting experimental modalities are also being developed with the potential to provide not just morphological but functional imaging. Techniques such as positron emission tomography (PET......) and high-resolution computerized tomography. Erosions are very clearly depicted using these modalities and MRI also allows imaging of soft tissues with assessment of joint inflammation. High-resolution ultrasound is a convenient clinical technique for the assessment of erosions, synovitis and tenosynovitis...

Imaging granulomatous lesions with optical coherence tomography

DEFF Research Database (Denmark)

Banzhaf, Christina; Jemec, Gregor B E

2012-01-01

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

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.

Positron emission tomography imaging of gene expression

International Nuclear Information System (INIS)

Tang Ganghua

2001-01-01

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

Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

DEFF Research Database (Denmark)

Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter

2010-01-01

, and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...

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

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.

Cerebral imaging and dementia

International Nuclear Information System (INIS)

Rascol, A.; Celsis, P.; Berry, I.

1989-01-01

Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease [fr

Cerebral imaging and dementia

Energy Technology Data Exchange (ETDEWEB)

Rascol, A.; Celsis, P.; Berry, I.

1989-02-01

Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease.

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

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.)

X-ray micro-tomography system for small-animal imaging with zoom-in imaging capability

International Nuclear Information System (INIS)

Chun, In Kon; Cho, Myung Hye; Lee, Sang Chul; Cho, Min Hyoung; Lee, Soo Yeol

2004-01-01

Since a micro-tomography system capable of μm-resolution imaging cannot be used for whole-body imaging of a small laboratory animal without sacrificing its spatial resolution, it is desirable for a micro-tomography system to have local imaging capability. In this paper, we introduce an x-ray micro-tomography system capable of high-resolution imaging of a local region inside a small animal. By combining two kinds of projection data, one from a full field-of-view (FOV) scan of the whole body and the other from a limited FOV scan of the region of interest (ROI), we have obtained zoomed-in images of the ROI without any contrast anomalies commonly appearing in conventional local tomography. For experimental verification of the zoom-in imaging capability, we have integrated a micro-tomography system using a micro-focus x-ray source, a 1248 x 1248 flat-panel x-ray detector, and a precision scan mechanism. The mismatches between the two projection data caused by misalignments of the scan mechanism have been estimated with a calibration phantom, and the mismatch effects have been compensated in the image reconstruction procedure. Zoom-in imaging results of bony tissues with a spatial resolution of 10 lp mm -1 suggest that zoom-in micro-tomography can be greatly used for high-resolution imaging of a local region in small-animal studies

Prognostic aspects of imaging method development

International Nuclear Information System (INIS)

Steinhart, L.

1987-01-01

A survey is presented of X-ray diagnostic methods and techniques and possibilities of their further development. Promising methods include direct imaging using digital radiography. In connection with computer technology these methods achieve higher resolution. The storage of obtained images in the computer memory will allow automated processing and evaluation and the use of expert systems. Development is expected to take place especially in computerized tomography using magnetic resonance, and positron computed tomography and other non-radioactive diagnostic methods. (J.B.). 5 figs., 1 tab., 1 ref

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)

A method for volume determination of the orbit and its contents by high resolution axial tomography and quantitative digital image analysis.

Science.gov (United States)

Cooper, W C

1985-01-01

The various congenital and acquired conditions which alter orbital volume are reviewed. Previous investigative work to determine orbital capacity is summarized. Since these studies were confined to postmortem evaluations, the need for a technique to measure orbital volume in the living state is presented. A method for volume determination of the orbit and its contents by high-resolution axial tomography and quantitative digital image analysis is reported. This procedure has proven to be accurate (the discrepancy between direct and computed measurements ranged from 0.2% to 4%) and reproducible (greater than 98%). The application of this method to representative clinical problems is presented and discussed. The establishment of a diagnostic system versatile enough to expand the usefulness of computerized axial tomography and polytomography should add a new dimension to ophthalmic investigation and treatment.

Technetium-99m-HMPAO labeled leukocyte single photon emission computerized tomography (SPECT) for assessing Crohn's disease extent and intestinal infiltration.

Science.gov (United States)

Biancone, L; Schillaci, O; Capoccetti, F; Bozzi, R M; Fina, D; Petruzziello, C; Geremia, A; Simonetti, G; Pallone, F

2005-02-01

Scintigraphy using radiolabeled leukocytes is a useful technique for assessing intestinal infiltration in Crohn's disease (CD). However, limits of planar images include overlapping activity in other organs and low specificity. To investigate the usefulness of (99m)Tc-HMPAO (hexametyl propylene amine oxime) labeled leukocyte single photon emission computerized tomography (SPECT) for assessing CD lesions, in comparison with planar images. Twenty-two inflammatory bowel disease patients (19 CD; 2 ulcerative colitis, UC; 1 ileal pouch) assessed by conventional endoscopy or radiology were enrolled. Leukocytes were labeled with (99m)Tc-HMPAO. SPECT images were acquired at 2 h and planar images at 30 min and 2 h. Bowel uptake was quantitated in nine regions (score 0-3). Both SPECT and planar images detected a negative scintigraphy (score 0) in the UC patient with no pouchitis and a positive scintigraphy (score 1-3) in the 21 patients showing active inflammation by conventional techniques. SPECT showed a higher global score than planar images (0.71 +/- 0.09 vs 0.30 +/- 0.05; p < 0.001), and in particular in the right iliac fossa (p= 0.003), right and left flank (p < 0.001; p= 0.02), hypogastrium (p= 0.002), and mesogastrium (p < 0.001). SPECT provided a better visualization and a higher uptake than planar images in patients with ileal and ileocolonic CD (6.45 +/- 0.82 vs 2.8 +/- 0.55, p < 0.001; 5.5 +/- 1.6 vs 2.6 +/- 0.7, p= 0.03), and with perianal CD (6.6 +/- 1.6 vs 3.4 +/- 1.2; p= 0.03). (99m)Tc-HMPAO labeled leukocyte SPECT provides a more detailed visualization of CD lesions than planar images. This technique may better discriminate between intestinal and bone marrow uptake, thus being useful for assessing CD lesions within the pelvis, including perianal disease.

Image processing tensor transform and discrete tomography with Matlab

CERN Document Server

Grigoryan, Artyom M

2012-01-01

Focusing on mathematical methods in computer tomography, Image Processing: Tensor Transform and Discrete Tomography with MATLAB(R) introduces novel approaches to help in solving the problem of image reconstruction on the Cartesian lattice. Specifically, it discusses methods of image processing along parallel rays to more quickly and accurately reconstruct images from a finite number of projections, thereby avoiding overradiation of the body during a computed tomography (CT) scan. The book presents several new ideas, concepts, and methods, many of which have not been published elsewhere. New co

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

International Nuclear Information System (INIS)

Mazoyer, B.M.

1988-01-01

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

MDCT for computerized volumetry of pneumothoraces in pediatric patients.

Science.gov (United States)

Cai, Wenli; Lee, Edward Y; Vij, Abhinav; Mahmood, Soran A; Yoshida, Hiroyuki

2011-03-01

Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f

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)

Fuzzy modeling of electrical impedance tomography images of the lungs

International Nuclear Information System (INIS)

Tanaka, Harki; Ortega, Neli Regina Siqueira; Galizia, Mauricio Stanzione; Borges, Joao Batista; Amato, Marcelo Britto Passos

2008-01-01

Objectives: Aiming to improve the anatomical resolution of electrical impedance tomography images, we developed a fuzzy model based on electrical impedance tomography's high temporal resolution and on the functional pulmonary signals of perfusion and ventilation. Introduction: Electrical impedance tomography images carry information about both ventilation and perfusion. However, these images are difficult to interpret because of insufficient anatomical resolution, such that it becomes almost impossible to distinguish the heart from the lungs. Methods: Electrical impedance tomography data from an experimental animal model were collected during normal ventilation and apnoea while an injection of hypertonic saline was administered. The fuzzy model was elaborated in three parts: a modeling of the heart, the pulmonary ventilation map and the pulmonary perfusion map. Image segmentation was performed using a threshold method, and a ventilation/perfusion map was generated. Results: Electrical impedance tomography images treated by the fuzzy model were compared with the hypertonic saline injection method and computed tomography scan images, presenting good results. The average accuracy index was 0.80 when comparing the fuzzy modeled lung maps and the computed tomography scan lung mask. The average ROC curve area comparing a saline injection image and a fuzzy modeled pulmonary perfusion image was 0.77. Discussion: The innovative aspects of our work are the use of temporal information for the delineation of the heart structure and the use of two pulmonary functions for lung structure delineation. However, robustness of the method should be tested for the imaging of abnormal lung conditions. Conclusions: These results showed the adequacy of the fuzzy approach in treating the anatomical resolution uncertainties in electrical impedance tomography images. (author)

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

Whole brain imaging with Serial Two-Photon Tomography

Directory of Open Access Journals (Sweden)

Stephen P Amato

2016-03-01

Full Text Available Imaging entire mouse brains at submicron resolution has historically been a challenging undertaking and largely confined to the province of dedicated atlasing initiatives. The has limited systematic investigations into important areas of neuroscience, such as neural circuits, brain mapping and neurodegeneration. In this paper, we describe in detail Serial Two-Photon (STP tomography, a robust, reliable method for imaging entire brains with histological detail. We provide examples of how the basic methodology can be extended to other imaging modalities, such as optical coherence tomography, in order to provide unique contrast mechanisms. Furthermore we provide a survey of the research that STP tomography has enabled in the field of neuroscience, provide examples of how this technology enables quantitative whole brain studies, and discuss the current limitations of STP tomography-based approaches

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

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.

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

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

Magnetic resonance imaging of the central nervous system

International Nuclear Information System (INIS)

Brant-Zawadzki, M.; Norman, D.

1987-01-01

This book presents the papers on technological advancement and diagnostic uses g magnetic resonance imaging. A comparative evaluation with computerized tomography is presented. Topics covered are imaging principles g magnetic resonance;instrumentation of magnetic resonance (MR);pathophysiology;quality and limitations g images;NMR imaging of brain and spinal cord;MR spectroscopy and its applications;neuroanatomy;Congenital malformations of brain and MR imaging;planning g MR imaging of spine and head and neck imaging

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.

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 ...

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.)

Quantitative information in medical imaging

International Nuclear Information System (INIS)

Deconinck, F.

1985-01-01

When developing new imaging or image processing techniques, one constantly has in mind that the new technique should provide a better, or more optimal answer to medical tasks than existing techniques do 'Better' or 'more optimal' imply some kind of standard by which one can measure imaging or image processing performance. The choice of a particular imaging modality to answer a diagnostic task, such as the detection of coronary artery stenosis is also based on an implicit optimalisation of performance criteria. Performance is measured by the ability to provide information about an object (patient) to the person (referring doctor) who ordered a particular task. In medical imaging the task is generally to find quantitative information on bodily function (biochemistry, physiology) and structure (histology, anatomy). In medical imaging, a wide range of techniques is available. Each technique has it's own characteristics. The techniques discussed in this paper are: nuclear magnetic resonance, X-ray fluorescence, scintigraphy, positron emission tomography, applied potential tomography, computerized tomography, and compton tomography. This paper provides a framework for the comparison of imaging performance, based on the way the quantitative information flow is altered by the characteristics of the modality

Small scale imaging using ultrasonic tomography

International Nuclear Information System (INIS)

Zakaria, Z.; Abdul Rahim, R.; Megat Ali, M.S.A.; Baharuddin, M.Y.; Jahidin, A.H.

2009-01-01

Ultrasound technology progressed through the 1960 from simple A-mode and B-mode scans to today M-mode and Doppler two dimensional (2-D) and even three dimensional (3-D) systems. Modern ultrasound imaging has its roots in sonar technology after it was first described by Lord John Rayleigh over 100 years ago on the interaction of acoustic waves with media. Tomography technique was developed as a diagnostic tool in the medical area since the early of 1970s. This research initially focused on how to retrieve a cross sectional images from living and non-living things. After a decade, the application of tomography systems span into the industrial area. However, the long exposure time of medical radiation-based method cannot tolerate the dynamic changes in industrial process two phase liquid/ gas flow system. An alternative system such as a process tomography systems, can give information on the nature of the flow regime characteristic. The overall aim of this paper is to investigate the use of a small scale ultrasonic tomography method based on ultrasonic transmission mode tomography for online monitoring of liquid/ gas flow in pipe/ vessel system through ultrasonic transceivers application. This non-invasive technique applied sixteen transceivers as the sensing elements to cover the pipe/ vessel cross section. The paper also details the transceivers selection criteria, hardware setup, the electronic measurement circuit and also the image reconstruction algorithm applied. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases. (author)

High-resolution time-lapse tomography of rat vertebrae during compressive loading: deformation response analysis

Czech Academy of Sciences Publication Activity Database

Fíla, Tomáš; Kytýř, Daniel; Zlámal, Petr; Kumpová, Ivana; Doktor, Tomáš; Koudelka_ml., Petr; Jiroušek, Ondřej

2014-01-01

Roč. 9, May (2014), C05054 ISSN 1748-0221. [International workshop on radiation imaging detectors /15./. Paris, 23.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP105/10/2305; GA MŠk(CZ) LO1219 Institutional support: RVO:68378297 Keywords : image reconstruction in medical imaging * computerized tomography * computed radiography Subject RIV: JJ - Other Materials Impact factor: 1.399, year: 2014 http://iopscience.iop.org/1748-0221/9/05/C05054

Multi-Detector Computed Tomography Imaging Techniques in Arterial Injuries

Directory of Open Access Journals (Sweden)

Cameron Adler

2018-04-01

Full Text Available Cross-sectional imaging has become a critical aspect in the evaluation of arterial injuries. In particular, angiography using computed tomography (CT is the imaging of choice. A variety of techniques and options are available when evaluating for arterial injuries. Techniques involve contrast bolus, various phases of contrast enhancement, multiplanar reconstruction, volume rendering, and maximum intensity projection. After the images are rendered, a variety of features may be seen that diagnose the injury. This article provides a general overview of the techniques, important findings, and pitfalls in cross sectional imaging of arterial imaging, particularly in relation to computed tomography. In addition, the future directions of computed tomography, including a few techniques in the process of development, is also discussed.

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)

Cellular imaging electron tomography and related techniques

CERN Document Server

2018-01-01

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

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)

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

Computerized tomographic evaluation of aortic prosthetic graft complications

International Nuclear Information System (INIS)

Kay, D.; Kalmar, J.A.

1985-01-01

Computerized tomography has been found to be an accurate and sensitive method of diagnosing complications of synthetic aortic grafts. Complications in this series of four cases included aortoesophageal fistula, aortoduodenal fistula, pseudoaneurysm, and retroperitoneal hematoma. 6 references, 5 figures

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

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.)

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

Imaging of the hip joint. Computed tomography versus magnetic resonance imaging

Science.gov (United States)

Lang, P.; Genant, H. K.; Jergesen, H. E.; Murray, W. R.

1992-01-01

The authors reviewed the applications and limitations of computed tomography (CT) and magnetic resonance (MR) imaging in the assessment of the most common hip disorders. Magnetic resonance imaging is the most sensitive technique in detecting osteonecrosis of the femoral head. Magnetic resonance reflects the histologic changes associated with osteonecrosis very well, which may ultimately help to improve staging. Computed tomography can more accurately identify subchondral fractures than MR imaging and thus remains important for staging. In congenital dysplasia of the hip, the position of the nonossified femoral head in children less than six months of age can only be inferred by indirect signs on CT. Magnetic resonance imaging demonstrates the cartilaginous femoral head directly without ionizing radiation. Computed tomography remains the imaging modality of choice for evaluating fractures of the hip joint. In some patients, MR imaging demonstrates the fracture even when it is not apparent on radiography. In neoplasm, CT provides better assessment of calcification, ossification, and periosteal reaction than MR imaging. Magnetic resonance imaging, however, represents the most accurate imaging modality for evaluating intramedullary and soft-tissue extent of the tumor and identifying involvement of neurovascular bundles. Magnetic resonance imaging can also be used to monitor response to chemotherapy. In osteoarthrosis and rheumatoid arthritis of the hip, both CT and MR provide more detailed assessment of the severity of disease than conventional radiography because of their tomographic nature. Magnetic resonance imaging is unique in evaluating cartilage degeneration and loss, and in demonstrating soft-tissue alterations such as inflammatory synovial proliferation.

Utilization of special computerized tomography and nuclear medicine techniques for quality control and for the optimization of combined precision chemotherapy and precision radiation therapy

International Nuclear Information System (INIS)

Wiley, A.L. Jr.; Wirtanen, G.W.; Chien, I.-C.

1984-01-01

A combination of precision (selective, intra-arterial) chemotherapy and precision radiotherapy can be used for advanced pancreatic, biliary tract, and sarcomatous malignancies. There were some remarkable responses, but also a few poor responses and even some morbidity. Accordingly, methods are developed of pre-selecting those patients whose tumors are likely to respond to such therapy, as well as methods for improving the therapeutic ratio by the rational optimization of combined therapy. Specifically, clinical tumor blood flow characteristics (monitored with nuclear medicine techniques) may provide useful criteria for such selection. The authors also evaluate qualitatively the drug distribution or exposure space with specialized color-coded computerized tomography images, which demonstrate spatially dependent enhancement of intra-arterial contrast in tumor and in adjacent normal tissues. Such clinical data can improve the quality control aspects of intra-arterial chemotherapy administration, as well as the possibility of achievement of a significant therapeutic ratio by the integration of precision chemotherapy and precision radiation therapy. (Auth.)

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

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.

Imaging Atherosclerosis with Hybrid Positron Emission Tomography/Magnetic Resonance Imaging

DEFF Research Database (Denmark)

Ripa, Rasmus Sejersten; Kjær, Andreas

2015-01-01

Noninvasive imaging of atherosclerosis could potentially move patient management towards individualized triage, treatment, and followup. The newly introduced combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system could emerge as a key player in this context. Both...

Cardiac Computed Tomography (Multidetector CT, or MDCT)

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 19,2016 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

Optical computed tomography for imaging the breast: first look

Science.gov (United States)

Grable, Richard J.; Ponder, Steven L.; Gkanatsios, Nikolaos A.; Dieckmann, William; Olivier, Patrick F.; Wake, Robert H.; Zeng, Yueping

2000-07-01

The purpose of the study is to compare computed tomography optical imaging with traditional breast imaging techniques. Images produced by computed tomography laser mammography (CTLMTM) scanner are compared with images obtained from mammography, and in some cases ultrasound and/or magnetic resonance imaging (MRI). During the CTLM procedure, a near infrared laser irradiates the breast and an array of photodiodes detectors records light scattered through the breast tissue. The laser and detectors rotate synchronously around the breast to acquire a series of slice data along the coronal place. The procedure is performed without any breast compression or optical matching fluid. Cross-sectional slices of the breast are produced using a reconstruction algorithm. Reconstruction based on the diffusion theory is used to produce cross-sectional slices of the breast. Multiple slice images are combined to produce a three dimensional volumetric array of the imaged breast. This array is used to derive axial and sagittal images of the breast corresponding to cranio-caudal and medio-lateral images used in mammography. Over 200 women and 3 men have been scanned in clinical trials. The most obvious features seen in images produced by the optical tomography scanner are vascularization and significant lesions. Breast features caused by fibrocystic changes and cysts are less obvious. Breast density does not appear to be a significant factor in the quality of the image. We see correlation of the optical image structure with that seen with traditional breast imaging techniques. Further testing is being conducted to explore the sensitivity and specificity of optical tomography of the breast.

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.

Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography, magnetic resonance imaging, and positron emission tomography

International Nuclear Information System (INIS)

Romero, J.A.; Kim, E.E.; Tresukosol, D.; Kudelka, A.P.; Edwards, C.L.; Kavanagh, J.J.

1995-01-01

We report a case of recurrent endodermal sinus tumor of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed. (orig.)

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)

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

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.

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.)

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.)

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.

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.

Dual scan CT image recovery from truncated projections

Science.gov (United States)

Sarkar, Shubhabrata; Wahi, Pankaj; Munshi, Prabhat

2017-12-01

There are computerized tomography (CT) scanners available commercially for imaging small objects and they are often categorized as mini-CT X-ray machines. One major limitation of these machines is their inability to scan large objects with good image quality because of the truncation of projection data. An algorithm is proposed in this work which enables such machines to scan large objects while maintaining the quality of the recovered image.

Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

DEFF Research Database (Denmark)

Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

1997-01-01

Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

Imaging of non-hodgkin lymphomas

DEFF Research Database (Denmark)

El-Galaly, Tarec Christoffer; Hutchings, Martin

2015-01-01

Optimal lymphoma management requires accurate pretreatment staging and reliable assessment of response, both during and after therapy. Positron emission tomography with computerized tomography (PET/CT) combines functional and anatomical imaging and provides the most sensitive and accurate methods...... for lymphoma imaging. New guidelines for lymphoma imaging and recently revised criteria for lymphoma staging and response assessment recommend PET/CT staging, treatment monitoring, and response evaluation in all FDG-avid lymphomas, while CT remains the method of choice for non-FDG-avid histologies. Since...... interim PET imaging has high prognostic value in lymphoma, a number of trials investigate PET-based, response-adapted therapy for non-Hodgkin lymphomas (NHL). PET response is the main determinant of response according to the new response criteria, but PET/CT has little or no role in routine surveillance...

SPECT and PET Serve as Molecular Imaging Techniques and in Vivo Biomarkers for Brain Metastases

Science.gov (United States)

Palumbo, Barbara; Buresta, Tommaso; Nuvoli, Susanna; Spanu, Angela; Schillaci, Orazio; Fravolini, Mario Luca; Palumbo, Isabella

2014-01-01

Nuclear medicine techniques (single photon emission computerized tomography, SPECT, and positron emission tomography, PET) represent molecular imaging tools, able to provide in vivo biomarkers of different diseases. To investigate brain tumours and metastases many different radiopharmaceuticals imaged by SPECT and PET can be used. In this review the main and most promising radiopharmaceuticals available to detect brain metastases are reported. Furthermore the diagnostic contribution of the combination of SPECT and PET data with radiological findings (magnetic resonance imaging, MRI) is discussed. PMID:24897023

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)

Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction.

Science.gov (United States)

Freyer, Marcus; Ale, Angelique; Schulz, Ralf B; Zientkowska, Marta; Ntziachristos, Vasilis; Englmeier, Karl-Hans

2010-01-01

The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.

Evaluation of three imaging instruments in dogs with liver hematomas: concise communication

International Nuclear Information System (INIS)

Frick, M.P.; Knight, L.C.; Ponto, R.A.; Loken, M.K.

1979-01-01

Single-gamma emission computerized tomography (ECT) was compared with transmission computerized tomography (TCT) and scintillation-camera imaging (SC) in eight dogs with acute, solitary hematomas in the left liver lobe. The superior performance of TCT was attributed to its inherently better spatial resolution than those of ECT or SC, and to the fact that studies with TCT could be performed during apnea. ECT was more sensitive than SC to small changes in the spatial distribution of radionuclides. In addition, the ECT, by virtue of its sectioning capability, was more sensitive than is SC to differences in radionuclide concentrations at the same depth in an organ

Computerized system for measuring cerebral metabolism

International Nuclear Information System (INIS)

McGlone, J.S.; Hibbard, L.S.; Hawkins, R.A.; Kasturi, R.

1987-01-01

A computerized stereotactic measurement system for evaluating rat brain metabolism was developed to utilize the large amount of data generated by quantitative autoradiography. Conventional methods of measurement only analyze a small percent of these data because these methods are limited by instrument design and the subjectiveness of the investigator. However, a computerized system allows digital images to be analyzed by placing data at their appropriate three-dimensional stereotactic coordinates. The system automatically registers experimental data to a standard three-dimensional image using alignment, scaling, and matching operations. Metabolic activity in different neuronal structures is then measured by generating digital masks and superimposing them on to experimental data. Several experimental data sets were evaluated and it was noticed that the structures measured by the computerized system, had in general, lower metabolic activity than manual measurements had indicated. This was expected because the computerized system measured the structure over its volume while the manual readings were taken from the most active metabolic area of a particular structure

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.)

Reflection tomography from pre-stack migrated images; Tomographie de reflexion a partir des images migrees avant addition

Energy Technology Data Exchange (ETDEWEB)

Adler, F

1996-10-29

The application of reflection tomography to data from complex geological structures is very interesting in the hydrocarbons exploration. Indeed, it contributes to localize the hydrocarbons potential traps. The used reflection tomography method is faced with two major difficulties. Travel time picking is difficult or impossible in seismic time sections. The processing of multiple arrival travel times needs an adequate formulation of reflection tomography. In order to solve the first problem, we adopt the approach of the SMART (Sequential Migration Aided Reflection Tomography) method which is an original method for the implementation of migration velocity analysis. The velocity model is automatically calculated by reflection tomography. The kinematic data set for reflection tomography is constructed from pre-stack depth-migrated images that are interpreted in the chosen migration configuration. For the implementation of the SMART method in the common-offset domain, we propose an original formulation of reflection tomography that takes multiple arrival travel times, which are calculated from common-offset migrated images, into account. In this new formulation, we look for a model such that a modelling, which consists in shooting in this model from the source locations with some ray parameters at the source, matches some emergence conditions: for each offset, the rays emerge at the receiver locations (given by the offset) with the same travel times and the same travel time slopes as observed in the associated common-offset section. These conditions constitute the kinematic data set for tomographic inversion. The common-offset travel time slope is the difference between the ray parameter at the receiver and the ray parameter at the source. Therefore, the ray parameter at the source is an unknown and has to be determined together with the model parameters during inversion. (author)

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)

Positron emission tomography/computed tomography imaging and rheumatoid arthritis.

Science.gov (United States)

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

2014-03-01

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

Comparing imaging procedures: techniques and examples. Gastroenterology

International Nuclear Information System (INIS)

Malmud, L.S.

1982-01-01

The distinct advantages of nuclear medicine procedures, in comparison to radiography, contrast studies, computerized tomography and ultrasound, are emphasized. Scintigraphic methods offer quantitative data regarding function which competing imaging modalities are unable to provide, and make them the studies of choice in the evaluation of gastrointestinal physiology and functional abnormalities

Monte Carlo simulation of gamma ray tomography for image reconstruction

Energy Technology Data Exchange (ETDEWEB)

Guedes, Karlos A.N.; Moura, Alex; Dantas, Carlos; Melo, Silvio; Lima, Emerson, E-mail: karlosguedes@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Meric, Ilker [University of Bergen (Norway)

2015-07-01

The Monte Carlo simulations of known density and shape object was validate with Gamma Ray Tomography in static experiments. An aluminum half-moon piece placed inside a steel pipe was the MC simulation test object that was also measured by means of gamma ray transmission. Wall effect of the steel pipe due to irradiation geometry in a single pair source-detector tomography was evaluated by comparison with theoretical data. MCNPX code requires a defined geometry to each photon trajectory which practically prevents this usage for tomography reconstruction simulation. The solution was found by writing a program in Delphi language to create input files automation code. Simulations of tomography data by automated MNCPX code were carried out and validated by experimental data. Working in this sequence the produced data needed a databank to be stored. Experimental setup used a Cesium-137 isotopic radioactive source (7.4 × 109 Bq), and NaI(Tl) scintillation detector of (51 × 51) × 10−3 m crystal size coupled to a multichannel analyzer. A stainless steel tubes of 0,154 m internal diameter, 0.014 m thickness wall. The results show that the MCNPX simulation code adapted to automated input file is useful for generating a matrix data M(θ,t), of a computerized gamma ray tomography for any known density and regular shape object. Experimental validation used RMSE from gamma ray paths and from attenuation coefficient data. (author)

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.

Image processor for high resolution video

International Nuclear Information System (INIS)

Pessoa, P.P.; Assis, J.T.; Cardoso, S.B.; Lopes, R.T.

1989-01-01

In this paper, we discuss an image presentation and processing system developed in Turbo Pascal 5.0 Language. Our system allows the visualization and processing of images in 16 different colors, taken at a time from a set of 64 possible ones. Digital filters of the mean, mediam Laplacian, gradient and histograms equalization type have been implemented, so as to allow a better image quality. Possible applications of our system are also discussed e.g., satellites, computerized tomography, medicine, microscopes. (author) [pt

Proton computed tomography images with algebraic reconstruction

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-11

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

SPECT and PET Serve as Molecular Imaging Techniques and in Vivo Biomarkers for Brain Metastases

Directory of Open Access Journals (Sweden)

Barbara Palumbo

2014-06-01

Full Text Available Nuclear medicine techniques (single photon emission computerized tomography, SPECT, and positron emission tomography, PET represent molecular imaging tools, able to provide in vivo biomarkers of different diseases. To investigate brain tumours and metastases many different radiopharmaceuticals imaged by SPECT and PET can be used. In this review the main and most promising radiopharmaceuticals available to detect brain metastases are reported. Furthermore the diagnostic contribution of the combination of SPECT and PET data with radiological findings (magnetic resonance imaging, MRI is discussed.

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

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

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)

Basic principles of magnetic resonance imaging in cerebral ischemia and initial clinical experience

International Nuclear Information System (INIS)

Brant-Zawadzki, M.; Solomon, M.; Newton, T.H.; Weinstein, P.; Schmidley, J.; Norman, D.

1985-01-01

NMR tomography proved to be a method superior to computerized tomography (CT) in terms of sensitivity in the diagnosis of pathological changes in the brain. The article on hand gives a brief survey on the principle of the method and demonstrates the superiority of NMR tomography to CT exemplified by images taken from a number of cases. Instrumental factors influencing diagnosis of cerebral ischaemie are discussed. Clinical studies performed on more than 20 partients with suspected infarct revealed the superiority of NMR tomography to CT. (MG) [de

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

Overview of image reconstruction

International Nuclear Information System (INIS)

Marr, R.B.

1980-04-01

Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ∫f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, electron microscopy, acoustical imaging, geophysical tomography, nondestructive testing, and NMR zeugmatography. Then the various reconstruction algorithms are discussed in five classes: summation, or simple back-projection; convolution, or filtered back-projection; Fourier and other functional transforms; orthogonal function series expansion; and iterative methods. Certain more technical mathematical aspects of image reconstruction are considered from the standpoint of uniqueness, consistency, and stability of solution. The paper concludes by presenting certain open problems. 73 references

Detection of drugs and plastic explosives using neutron tomography

Energy Technology Data Exchange (ETDEWEB)

Ferreira, F.J.O. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)], E-mail: fferreira@ien.gov.br; Crispim, V.R; Silva, A.X. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear], E-mail: ademir@con.ufrj.br, E-mail: verginia@com.ufrj.br

2007-07-01

The unique ability of neutrons to image certain elements and isotopes that are either completely undetectable or poorly detected by other Non-Destructive-Assay (NDA) methods makes neutron radiography an important tool for the NDA community. Neutron radiography, like other imaging techniques takes a number of different forms (i.e. / that is film, radioscopic, transfer methods, tomography, etc.) In this work report the Neutron Tomography System developed, which will allow inspections NDA of samples with high efficiency, in terms of minors measure time and the result analysis, and the application for detection of drugs and plastic explosives, which is very important for the combat to the terrorism and drug trafficking. The neutron tomography system developed is third generation. Therefore a rotary table driven by a step motor connected to a computerized motion control system has been installed at the sample position. In parallel to this a suitable electronic imaging device has been designed and can be controlled by a computer in order to synchronize the software the detector and of the rotary table with the aim of an automation of measurements. To obtain 2D tomography image, a system with an electronic imaging system for producing real time neutron radiography. Images are processing digital for cancel random noise effects and to optimize spatial resolution. Finally, using a (ARIEN) algorithm reconstruction of tomography images by finite element maximum entropy. The system was installed adjacent to the exit of the J-9 irradiation channel of the Argonauta Reactor in the Nuclear Engineering Institute (IEN) - which is an organ of the National Nuclear Energy Commission (CNEN - Brazil).The Argonauta reactor operates at 340 watts, being that the characteristics of the neutron beam on the plane of the image: thermal neutron flux 4,46 x10{sup 5} n/cm{sup 2}s. In the tomography assays, several encapsulated samples of paste, rock and cocaine powder and plastic explosives devices

Detection of drugs and plastic explosives using neutron tomography

International Nuclear Information System (INIS)

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

2007-01-01

The unique ability of neutrons to image certain elements and isotopes that are either completely undetectable or poorly detected by other Non-Destructive-Assay (NDA) methods makes neutron radiography an important tool for the NDA community. Neutron radiography, like other imaging techniques takes a number of different forms (i.e. / that is film, radioscopic, transfer methods, tomography, etc.) In this work report the Neutron Tomography System developed, which will allow inspections NDA of samples with high efficiency, in terms of minors measure time and the result analysis, and the application for detection of drugs and plastic explosives, which is very important for the combat to the terrorism and drug trafficking. The neutron tomography system developed is third generation. Therefore a rotary table driven by a step motor connected to a computerized motion control system has been installed at the sample position. In parallel to this a suitable electronic imaging device has been designed and can be controlled by a computer in order to synchronize the software the detector and of the rotary table with the aim of an automation of measurements. To obtain 2D tomography image, a system with an electronic imaging system for producing real time neutron radiography. Images are processing digital for cancel random noise effects and to optimize spatial resolution. Finally, using a (ARIEN) algorithm reconstruction of tomography images by finite element maximum entropy. The system was installed adjacent to the exit of the J-9 irradiation channel of the Argonauta Reactor in the Nuclear Engineering Institute (IEN) - which is an organ of the National Nuclear Energy Commission (CNEN - Brazil).The Argonauta reactor operates at 340 watts, being that the characteristics of the neutron beam on the plane of the image: thermal neutron flux 4,46 x10 5 n/cm 2 s. In the tomography assays, several encapsulated samples of paste, rock and cocaine powder and plastic explosives devices. (author)

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.

Tomografía axial computarizada en pacientes con enfermedades cerebrovasculares hemorrágicas Computerized axial tomography in patients with hemorrhagic cerebrovascular diseases

Directory of Open Access Journals (Sweden)

Solángel Bolaños Vaillant

2009-10-01

Full Text Available Se efectuó un estudio descriptivo y transversal de 196 pacientes con enfermedad cerebrovascular hemorrágica, que abarcó desde enero del 2004 hasta igual mes del 2005 en el Hospital Provincial Docente “Saturnino Lora” de Santiago de Cuba, a los cuales se indicó una tomografía axial computarizada. Al relacionar las imágenes tomográficas con los síntomas y signos presentados por los enfermos, se halló lenguaje tropeloso en todos ellos; predominio de hematomas intraparenquimatosos, generalmente en ganglios basales y región temporal, así como primacía de la hipertensión arterial entre los antecedentes patológicos más importantes. Se concluyó que la tomografía axial computarizada es un medio para diagnóstico certero en las urgencias médicas por esa grave afección.A descriptive and cross sectional study of 196 patients with cerebrovascular hemorrhagic disease was carried out from January, 2004 to the same month of 2005 in "Saturnino Lora" Teaching Provincial Hospital from Santiago de Cuba, to whom a computerized axial tomography was indicated. When relating the tomographic images with the symptoms and signs which they presented, trouble speaking was detected in all of them; prevalence of intraparenchymatous hematomas, generally in basal ganglia and temporal region, as well as prevalence of hypertension among the most important pathological history. It was concluded that computarized axial tomography is a mean for precise diagnosis in medical emergencies due to that serious disorder.

Computerized detection of lacunar infarcts in brain MR images

International Nuclear Information System (INIS)

Uchiyama, Yoshikazu; Matsui, Atsushi; Yokoyama, Ryujiro

2007-01-01

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

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.)

Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

International Nuclear Information System (INIS)

Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

2015-01-01

Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

Nonoperative treatment of splenic trauma: usefulness of computed tomography

International Nuclear Information System (INIS)

Resende, Vivian; Tavares Junior, Wilson Campos; Vieira, Jose Nelson Mendes; Drumond, Domingos Andre Fernandes

2005-01-01

Objective: to report the results of use of conservative treatment in patients with splenic trauma and to emphasize the usefulness of computed tomography in these cases. Material and method: sixty-nine cases of pediatric patients with blunt abdominal trauma seen from from January 2001 to June 2004 at the level I trauma center were retrospectively studied. Forty-four of these patients were submitted to nonoperative treatment and the clinical follow-up was performed by computerized tomography. All patients had been diagnosed with splenic injury by computerized tomography.Results: the causes of the injuries were motor vehicle accident in 12 (27.2%) patients, bicycle accident in nine (20.4%) patients, and falls in 23 (52.2%) patients. Two (3.7%) patients died from associated injuries. The mean duration of hospital stay was six days. The mean age of the patients was nine years. Conclusion: conservative treatment for blunt splenic trauma is performed with the aim of reducing costs and risks for the patients, and computerized tomography should be routinely used. No posterior complications were observed in this approach. (author)

Tomography methods for diagnostic examination of cerebrovascular disease: a comparative evaluation of SPECT, PET and MR/CT findings

International Nuclear Information System (INIS)

Reiche, W.; Kaiser, H.J.; Weiller, C.; Altehoefer, C.; Buell, U.; Isensee, C.

1991-01-01

Single Photon Emissions Computerized Tomography (SPECT), Positron Emissions Tomography (PET), Magnetic Resonance Tomography (MR), and Transmission Computerized Tomography (CT) complement each other and lead to a consideration of the cerebrovascular disease under patho-physiological aspects. Indications for the combined application of functionally oriented (SPECT/PET) and morphologically oriented (CT/MR) examination methods with cerebrovascular disease are presented. (orig./MG) [de

Utility of the computed tomography indices on cone beam computed tomography images in the diagnosis of osteoporosis in women

International Nuclear Information System (INIS)

Koh, Kwang Joon; Kim, Kyung A

2011-01-01

This study evaluated the potential use of the computed tomography indices (CTI) on cone beam CT (CBCT) images for an assessment of the bone mineral density (BMD) in postmenopausal osteoporotic women. Twenty-one postmenopausal osteoporotic women and 21 postmenopausal healthy women were enrolled as the subjects. The BMD of the lumbar vertebrae and femur were calculated by dual energy X-ray absorptiometry (DXA) using a DXA scanner. The CBCT images were obtained from the unilateral mental foramen region using a PSR-9000N Dental CT system. The axial, sagittal, and coronal images were reconstructed from the block images using OnDemend3D. The new term 'CTI' on CBCT images was proposed. The relationship between the CT measurements and BMDs were assessed and the intra-observer agreement was determined. There were significant differences between the normal and osteoporotic groups in the computed tomography mandibular index superior (CTI(S)), computed tomography mandibular index inferior (CTI(I)), and computed tomography cortical index (CTCI). On the other hand, there was no difference between the groups in the computed tomography mental index (CTMI: inferior cortical width). CTI(S), CTI(I), and CTCI on the CBCT images can be used to assess the osteoporotic women.

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)

Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

Science.gov (United States)

Scripes, Paola G; Yaparpalvi, Ravindra

2012-09-01

The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

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)

SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

International Nuclear Information System (INIS)

Lu, W; Wang, J; Zhang, H

2015-01-01

Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

Energy Technology Data Exchange (ETDEWEB)

Lu, W; Wang, J; Zhang, H [University of Maryland School of Medicine, Baltimore, MD (United States)

2015-06-15

Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

Electrical Resistance Tomography imaging of concrete

KAUST Repository

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

2010-01-01

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

Quantitative damage imaging using Lamb wave diffraction tomography

International Nuclear Information System (INIS)

Zhang Hai-Yan; Ruan Min; Zhu Wen-Fa; Chai Xiao-Dong

2016-01-01

In this paper, we investigate the diffraction tomography for quantitative imaging damages of partly through-thickness holes with various shapes in isotropic plates by using converted and non-converted scattered Lamb waves generated numerically. Finite element simulations are carried out to provide the scattered wave data. The validity of the finite element model is confirmed by the comparison of scattering directivity pattern (SDP) of circle blind hole damage between the finite element simulations and the analytical results. The imaging method is based on a theoretical relation between the one-dimensional (1D) Fourier transform of the scattered projection and two-dimensional (2D) spatial Fourier transform of the scattering object. A quantitative image of the damage is obtained by carrying out the 2D inverse Fourier transform of the scattering object. The proposed approach employs a circle transducer network containing forward and backward projections, which lead to so-called transmission mode (TMDT) and reflection mode diffraction tomography (RMDT), respectively. The reconstructed results of the two projections for a non-converted S0 scattered mode are investigated to illuminate the influence of the scattering field data. The results show that Lamb wave diffraction tomography using the combination of TMDT and RMDT improves the imaging effect compared with by using only the TMDT or RMDT. The scattered data of the converted A0 mode are also used to assess the performance of the diffraction tomography method. It is found that the circle and elliptical shaped damages can still be reasonably identified from the reconstructed images while the reconstructed results of other complex shaped damages like crisscross rectangles and racecourse are relatively poor. (special topics)

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)

Emission tomography for adrenal imaging

International Nuclear Information System (INIS)

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

1980-01-01

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

Spatial image modulation to improve performance of computed tomography imaging spectrometer

Science.gov (United States)

Bearman, Gregory H. (Inventor); Wilson, Daniel W. (Inventor); Johnson, William R. (Inventor)

2010-01-01

Computed tomography imaging spectrometers ("CTIS"s) having patterns for imposing spatial structure are provided. The pattern may be imposed either directly on the object scene being imaged or at the field stop aperture. The use of the pattern improves the accuracy of the captured spatial and spectral information.

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

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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

Single photon emission computed tomography in AIDS dementia complex

International Nuclear Information System (INIS)

Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

1988-01-01

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

Head and neck: normal variations and benign findings in FDG positron emission tomography/computed tomography imaging.

Science.gov (United States)

Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

2014-04-01

Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories. Copyright © 2014 Elsevier Inc. All rights reserved.

New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images

International Nuclear Information System (INIS)

Duan, Jinming; Bai, Li; Tench, Christopher; Gottlob, Irene; Proudlock, Frank

2015-01-01

Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation. (paper)

Cross-sectional imaging with rotational panoramic X-ray machine for preoperative assessment of dental implant site. Comparisons of imaging properties with conventional film tomography and computed tomography

International Nuclear Information System (INIS)

Makihara, Masahiro; Nishikawa, Keiichi; Kuroyanagi, Kinya

2001-01-01

To clarify the validity of cross-sectional imaging with rotational panoramic x-ray machine for preoperative assessment of the dental implant site, the imaging properties were compared with those of spiral tomography and multi-planer reconstruction (MPR) manipulation of x-ray computed tomography. Cross-sectional imaging of the maxilla and mandible of an edentulous dry skull was performed by each technique at an image layer thickness of 1 mm. Steel spheres were used to identify cross-sectional planes and measure distance. Six oral radiologists scored the image clarity of structures with 5-grade rating scales and measured the distance between images of 2 steel spheres. Each measured distance was divided by the magnification factor. The actual distance was also measured on the skull. The score and the distance were statistically compared. The Spearman's rank correlation coefficients for the score and the absolute values of the difference in distances measured by different observers were calculated as test units to compare inter-observer agreements statistically. The same observation and measurement were repeated to compare intra-observer agreement. Image clarity of the linear tomography available with a panoramic machine was comparable to spiral tomography and superior to MPR, except for the cortical bone on the lingual side. The inter- and intra-observer agreements were comparable. The accuracy for measurement of distance, the inter- and intra-observer agreements were also comparable to the spiral tomography and superior to those of MPR. Therefore, it is concluded that cross-sectional imaging with a rotational panoramic x-ray machine is useful for preoperative assessment of the dental implant site. (author)

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.)

Intracranial arterial anatomy: evaluation by computed tomography angiography

International Nuclear Information System (INIS)

Regattieri, Neysa Aparecida Tinoco; Haetinger, Rainer Guilherme; Liberti, Edson Aparecido

2010-01-01

By many decades, the intracranial arteries study was realized exclusively by angiography through selective arterial catheterization. Nowadays, with the technologic evaluation of computerized tomography devices with multi detectors allowing acquisitions with even more thinner slices, higher speed and better resolution, it had appeared a new modality of investigation: the computed tomography angiography, less invasive and with minor morbidity than conventional arteriography. Many studies in the literature have been analyzing the sensibility of the new method for the detection of intracranial aneurysms and comparing them with the conventional arteriography. There is a necessity to recognize the normal intracranial arterial anatomy and its variations using images obtained from multiplanar reformations, in order to give important information for surgeries strategies, such as wall calcifications, aneurismatic neck position and relationships with surrounding anatomical structures. (author)

A Superresolution Image Reconstruction Algorithm Based on Landweber in Electrical Capacitance Tomography

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Chen Deyun

2013-01-01

Full Text Available According to the image reconstruction accuracy influenced by the “soft field” nature and ill-conditioned problems in electrical capacitance tomography, a superresolution image reconstruction algorithm based on Landweber is proposed in the paper, which is based on the working principle of the electrical capacitance tomography system. The method uses the algorithm which is derived by regularization of solutions derived and derives closed solution by fast Fourier transform of the convolution kernel. So, it ensures the certainty of the solution and improves the stability and quality of image reconstruction results. Simulation results show that the imaging precision and real-time imaging of the algorithm are better than Landweber algorithm, and this algorithm proposes a new method for the electrical capacitance tomography image reconstruction algorithm.

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)

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)

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.

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)

Neural network and its application to CT imaging

Energy Technology Data Exchange (ETDEWEB)

Nikravesh, M.; Kovscek, A.R.; Patzek, T.W. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-02-01

We present an integrated approach to imaging the progress of air displacement by spontaneous imbibition of oil into sandstone. We combine Computerized Tomography (CT) scanning and neural network image processing. The main aspects of our approach are (I) visualization of the distribution of oil and air saturation by CT, (II) interpretation of CT scans using neural networks, and (III) reconstruction of 3-D images of oil saturation from the CT scans with a neural network model. Excellent agreement between the actual images and the neural network predictions is found.

Review of cardiovascular imaging in the journal of nuclear cardiology in 2015. Part 1 of 2: Plaque imaging, positron emission tomography, computed tomography, and magnetic resonance.

Science.gov (United States)

AlJaroudi, Wael A; Hage, Fadi G

2016-02-01

In 2015, many original articles pertaining to cardiovascular imaging with impressive quality were published in the Journal of Nuclear Cardiology. In a set of 2 articles, we provide an overview of these contributions to facilitate for the interested reader a quick review of the advancements that occurred in the field over this year. In this first article, we focus on arterial plaque imaging, cardiac positron emission tomography, computed tomography, and magnetic resonance imaging.

Direct image reconstruction with limited angle projection data for computerized tomography

International Nuclear Information System (INIS)

Inouye, T.

1980-01-01

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

Anatomy-based automatic detection and segmentation of major vessels in thoracic CTA images

International Nuclear Information System (INIS)

Zou Xiaotao; Liang Jianming; Wolf, M.; Salganicoff, M.; Krishnan, A.; Nadich, D.P.

2007-01-01

Existing approaches for automated computerized detection of pulmonary embolism (PE) using computed tomography angiography (CTA) usually focus on segmental and sub-segmental emboli. The goal of our current research is to extend our existing approach to automated detection of central PE. In order to detect central emboli, the major vessels must be first identified and segmented automatically. This submission presents an anatomy-based method for automatic computerized detection and segmentation of aortas and main pulmonary arteries in CTA images. (orig.)

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

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.

Automated computerized scheme for distinction between benign and malignant solitary pulmonary nodules on chest images

International Nuclear Information System (INIS)

Aoyama, Masahito; Li Qiang; Katsuragawa, Shigehiko; MacMahon, Heber; Doi, Kunio

2002-01-01

A novel automated computerized scheme has been developed to assist radiologists for their distinction between benign and malignant solitary pulmonary nodules on chest images. Our database consisted of 55 chest radiographs (33 primary lung cancers and 22 benign nodules). In this method, the location of a nodule was indicated first by a radiologist. The difference image with a nodule was produced by use of filters and then represented in a polar coordinate system. The nodule was segmented automatically by analysis of contour lines of the gray-level distribution based on the polar-coordinate representation. Two clinical parameters (age and sex) and 75 image features were determined from the outline, the image, and histogram analysis for inside and outside regions of the segmented nodule. Linear discriminant analysis (LDA) and knowledge about benign and malignant nodules were used to select initial feature combinations. Many combinations for subgroups of 77 features were evaluated as input to artificial neural networks (ANNs). The performance of ANNs with the selected 7 features by use of the round-robin test showed Az=0.872, which was greater than Az=0.854 obtained previously with the manual method (P=0.53). The performance of LDA (Az=0.886) was slightly improved compared to that of ANNs (P=0.59) and was greater than that of the manual method (Az=0.854) reported previously (P=0.40). The high level of its performance indicates the potential usefulness of this automated computerized scheme in assisting radiologists as a second opinion for distinction between benign and malignant solitary pulmonary nodules on chest images

Bayesian image reconstruction for improving detection performance of muon tomography.

Science.gov (United States)

Wang, Guobao; Schultz, Larry J; Qi, Jinyi

2009-05-01

Muon tomography is a novel technology that is being developed for detecting high-Z materials in vehicles or cargo containers. Maximum likelihood methods have been developed for reconstructing the scattering density image from muon measurements. However, the instability of maximum likelihood estimation often results in noisy images and low detectability of high-Z targets. In this paper, we propose using regularization to improve the image quality of muon tomography. We formulate the muon reconstruction problem in a Bayesian framework by introducing a prior distribution on scattering density images. An iterative shrinkage algorithm is derived to maximize the log posterior distribution. At each iteration, the algorithm obtains the maximum a posteriori update by shrinking an unregularized maximum likelihood update. Inverse quadratic shrinkage functions are derived for generalized Laplacian priors and inverse cubic shrinkage functions are derived for generalized Gaussian priors. Receiver operating characteristic studies using simulated data demonstrate that the Bayesian reconstruction can greatly improve the detection performance of muon tomography.

Imaging actinic keratosis by high-definition optical coherence tomography. Histomorphologic correlation

DEFF Research Database (Denmark)

Boone, Marc A L M; Norrenberg, Sarah; Jemec, Gregor B E

2013-01-01

With the continued development of non-invasive therapies for actinic keratosis such as PDT and immune therapies, the non-invasive diagnosis and monitoring become increasingly relevant. High-definition optical coherence tomography is a high-resolution imaging tool, with micrometre resolution in both...... transversal and axial directions, enable to visualize individual cells up to a depth of around 570 μm filling the imaging gap between conventional optical coherence tomography and reflectance confocal microscopy. We sought to determine the feasibility of detecting and grading of actinic keratosis...... by this technique using criteria defined for reflectance confocal microscopy compared to histology. In this pilot study, skin lesions of 17 patients with a histologically proven actinic keratosis were imaged by high-definition optical coherence tomography just before excision and images analysed qualitatively...

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.

Nuclear magnetic resonance

International Nuclear Information System (INIS)

Ethier, R.; Melanson, D.; Peters, T.M.

1983-01-01

Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr

Positron emission tomography/computed tomography--imaging protocols, artifacts, and pitfalls.

Science.gov (United States)

Bockisch, Andreas; Beyer, Thomas; Antoch, Gerald; Freudenberg, Lutz S; Kühl, Hilmar; Debatin, Jörg F; Müller, Stefan P

2004-01-01

There has been a longstanding interest in fused images of anatomical information, such as that provided by computed tomography (CT) or magnetic resonance imaging (MRI) systems, with biological information obtainable by positron emission tomography (PET). The near-simultaneous data acquisition in a fixed combination of a PET and a CT scanner in a combined PET/CT imaging system minimizes spatial and temporal mismatches between the modalities by eliminating the need to move the patient in between exams. In addition, using the fast CT scan for PET attenuation correction, the duration of the examination is significantly reduced compared to standalone PET imaging with standard rod-transmission sources. The main source of artifacts arises from the use of the CT-data for scatter and attenuation correction of the PET images. Today, CT reconstruction algorithms cannot account for the presence of metal implants, such as dental fillings or prostheses, properly, thus resulting in streak artifacts, which are propagated into the PET image by the attenuation correction. The transformation of attenuation coefficients at X-ray energies to those at 511 keV works well for soft tissues, bone, and air, but again is insufficient for dense CT contrast agents, such as iodine or barium. Finally, mismatches, for example, due to uncoordinated respiration result in incorrect attenuation-corrected PET images. These artifacts, however, can be minimized or avoided prospectively by careful acquisition protocol considerations. In doubt, the uncorrected images almost always allow discrimination between true and artificial finding. PET/CT has to be integrated into the diagnostic workflow for harvesting the full potential of the new modality. In particular, the diagnostic power of both, the CT and the PET within the combination must not be underestimated. By combining multiple diagnostic studies within a single examination, significant logistic advantages can be expected if the combined PET

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)

Use of morphologic filters in the computerized detection of lung nodules in digital chest images

International Nuclear Information System (INIS)

Yoshimura, H.; Giger, M.L.; Doi, K.; Ahn, N.; MacMahon, H.

1989-01-01

The authors have previously described a computerized scheme for the detection of lung nodules based on a difference-image approach, which had a detection accuracy of 70% with 7--8 false positives per image. Currently, they are investigating morphologic filters for the further enhancement/suppression of nodule-signals and the removal of false-positives. Gray-level morphologic filtering is performed on clinical chest radiographs digitized with an optical drum scanner. Various shapes and sequences of erosion and dilation filters (i.e., determination of the minimum and maximum gray levels, respectively) were examined for signal enhancement and suppression for sue in the difference- image approach

Computerized assessment of body image in anorexia nervosa and bulimia nervosa: comparison with standardized body image assessment tool.

Science.gov (United States)

Caspi, Asaf; Amiaz, Revital; Davidson, Noa; Czerniak, Efrat; Gur, Eitan; Kiryati, Nahum; Harari, Daniel; Furst, Miriam; Stein, Daniel

2017-02-01

Body image disturbances are a prominent feature of eating disorders (EDs). Our aim was to test and evaluate a computerized assessment of body image (CABI), to compare the body image disturbances in different ED types, and to assess the factors affecting body image. The body image of 22 individuals undergoing inpatient treatment with restricting anorexia nervosa (AN-R), 22 with binge/purge AN (AN-B/P), 20 with bulimia nervosa (BN), and 41 healthy controls was assessed using the Contour Drawing Rating Scale (CDRS), the CABI, which simulated the participants' self-image in different levels of weight changes, and the Eating Disorder Inventory-2-Body Dissatisfaction (EDI-2-BD) scale. Severity of depression and anxiety was also assessed. Significant differences were found among the three scales assessing body image, although most of their dimensions differentiated between patients with EDs and controls. Our findings support the use of the CABI in the comparison of body image disturbances in patients with EDs vs. Moreover, the use of different assessment tools allows for a better understanding of the differences in body image disturbances in different ED types.

A bio-electromechanical imaging technique with combined electrical impedance and ultrasound tomography

International Nuclear Information System (INIS)

Steiner, G; Watzenig, D; Soleimani, M

2008-01-01

Electrical impedance tomography (EIT) seeks to image the electrical conductivity of an object using electrical impedance measurement data at its periphery. Ultrasound reflection tomography (URT) is an imaging modality that is able to generate images of mechanical properties of the object in terms of acoustic impedance changes. Both URT and EIT have the potential to be used in various medical applications. In this paper we focus on breast tumour detection. Both URT and EIT belong to soft field tomography and suffer from the small amounts of available data and the inherently ill-posed nature of the inverse problems. These facts result in limited achievable reconstruction accuracy and resolution. A dual bio-electromechanical tomography system using ultrasound and electrical tomography is proposed in this paper to improve the detection of the small-size tumour. Data fusion techniques are implemented to combine the EIT/URT data. Based on simulations, we demonstrate the improvement of detection of small size anomalies and improved depth detection compared to single modality soft field tomography

Diagnostic information management system for the evaluation of medical images

Energy Technology Data Exchange (ETDEWEB)

Higa, Toshiaki; Torizuka, Kanji; Minato, Kotaro; Komori, Masaru; Hirakawa, Akina

1985-04-01

A practical, small and low-cost diagnostic information management system has been developed for a comparative study of various medical imaging procedures, including ordinary radiography, X-ray computed tomography, emission computed tomography, and so forth. The purpose of the system is to effectively manage the original image data files and diagnostic descriptions during the various imaging procedures. A diagnostic description of each imaging procedure for each patient is made on a hand-sort punched-card with line-drawings and ordinary medical terminology and then coded and computerized using Index for Roentgen Diagnoses (American College of Radiology). A database management software (DB Master) on a personal computer (Apple II) is used for searching for patients' records on hand-sort punched-cards and finally original medical images. Discussed are realistic use of medical images and an effective form of diagnostic descriptions.

Diagnostic information management system for the evaluation of medical images

International Nuclear Information System (INIS)

Higa, Toshiaki; Torizuka, Kanji; Minato, Kotaro; Komori, Masaru; Hirakawa, Akina.

1985-01-01

A practical, small and low-cost diagnostic information management system has been developed for a comparative study of various medical imaging procedures, including ordinary radiography, X-ray computed tomography, emission computed tomography, and so forth. The purpose of the system is to effectively manage the original image data files and diagnostic descriptions during the various imaging procedures. A diagnostic description of each imaging procedure for each patient is made on a hand-sort punched-card with line-drawings and ordinary medical terminology and then coded and computerized using Index for Roentgen Diagnoses (American College of Radiology). A database management software (DB Master) on a personal computer (Apple II) is used for searching for patients' records on hand-sort punched-cards and finally original medical images. Discussed are realistic use of medical images and an effective form of diagnostic descriptions. (author)

Comparison of radiation absorbed dose in target organs in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography and computed tomography

Directory of Open Access Journals (Sweden)

Panjnoush M.

2009-12-01

Full Text Available "nBackground and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT and computed tomography (CT."nMaterials and Methods: Thermoluminescent dosimeters (TLD were implanted in 14 sites of RANDO phantom to measure average tissue absorbed dose in thyroid gland, parotid glands, submandibular glands, sublingual gland, lenses and buccal skin. The Promax (PLANMECA, Helsinki, Finland unit was selected for Panoramic, conventional linear tomography and cone beam computed tomography examinations and spiral Hispeed/Fxi (General Electric,USA was selected for CT examination. The average tissue absorbed doses were used for the calculation of the equivalent and effective doses in each organ."nResults: The average absorbed dose for Panoramic ranged from 0.038 mGY (Buccal skin to 0.308 mGY (submandibular gland, linear tomography ranged from 0.048 mGY (Lens to 0.510 mGY (submandibular gland,CBCT ranged from 0.322 mGY (thyroid glad to 1.144 mGY (Parotid gland and in CT ranged from 2.495 mGY (sublingual gland to 3.424 mGY (submandibular gland. Total effective dose in CBCT is 5 times greater than Panoramic and 4 times greater than linear tomography, and in CT, 30 and 22 times greater than Panoramic and linear tomography, respectively. Total effective dose in CT is 6 times greater than CBCT."nConclusion: For obtaining 3-dimensional (3D information in maxillofacial region, CBCT delivers the lower dose than CT, and should be preferred over a medical CT imaging. Furthermore, during maxillofacial imaging, salivary glands receive the highest dose of radiation.

Medical imaging technology

CERN Document Server

Haidekker, Mark A

2013-01-01

Biomedical imaging is a relatively young discipline that started with Conrad Wilhelm Roentgen’s discovery of the x-ray in 1885. X-ray imaging was rapidly adopted in hospitals around the world. However, it was the advent of computerized data and image processing that made revolutionary new imaging modalities possible. Today, cross-sections and three-dimensional reconstructions of the organs inside the human body is possible with unprecedented speed, detail and quality. This book provides an introduction into the principles of image formation of key medical imaging modalities: X-ray projection imaging, x-ray computed tomography, magnetic resonance imaging, ultrasound imaging, and radionuclide imaging. Recent developments in optical imaging are also covered. For each imaging modality, the introduction into the physical principles and sources of contrast is provided, followed by the methods of image formation, engineering aspects of the imaging devices, and a discussion of strengths and limitations of the modal...

Diagnostic performance of fluorodeoxyglucose positron emission tomography/magnetic resonance imaging fusion images of gynecological malignant tumors. Comparison with positron emission tomography/computed tomography

International Nuclear Information System (INIS)

Nakajo, Kazuya; Tatsumi, Mitsuaki; Inoue, Atsuo

2010-01-01

We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies. A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation). For the first evaluation, the score for T2WI (4.68±0.65) was significantly higher than that for CT (3.54±1.02) or T1WI (3.71±0.97) (P<0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74±0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06±0.68) or T1WI (2.23±0.61) (P<0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72±0.54) localized the lesion significantly more convincingly than PET/CT (2.23±0.50) or PET/T1WI (2.29±0.53) (P<0.01). PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies. (author)

Photoacoustic tomography of human hepatic malignancies using intraoperative indocyanine green fluorescence imaging.

Directory of Open Access Journals (Sweden)

Akinori Miyata

Full Text Available Recently, fluorescence imaging following the preoperative intravenous injection of indocyanine green has been used in clinical settings to identify hepatic malignancies during surgery. The aim of this study was to evaluate the ability of photoacoustic tomography using indocyanine green as a contrast agent to produce representative fluorescence images of hepatic tumors by visualizing the spatial distribution of indocyanine green on ultrasonographic images. Indocyanine green (0.5 mg/kg, intravenous was preoperatively administered to 9 patients undergoing hepatectomy. Intraoperatively, photoacoustic tomography was performed on the surface of the resected hepatic specimens (n = 10 under excitation with an 800 nm pulse laser. In 4 hepatocellular carcinoma nodules, photoacoustic imaging identified indocyanine green accumulation in the cancerous tissue. In contrast, in one hepatocellular carcinoma nodule and five adenocarcinoma foci (one intrahepatic cholangiocarcinoma and 4 colorectal liver metastases, photoacoustic imaging delineated indocyanine green accumulation not in the cancerous tissue but rather in the peri-cancerous hepatic parenchyma. Although photoacoustic tomography enabled to visualize spatial distribution of ICG on ultrasonographic images, which was consistent with fluorescence images on cut surfaces of the resected specimens, photoacoustic signals of ICG-containing tissues decreased approximately by 40% even at 4 mm depth from liver surfaces. Photoacoustic tomography using indocyanine green also failed to identify any hepatocellular carcinoma nodules from the body surface of model mice with non-alcoholic steatohepatitis. In conclusion, photoacoustic tomography has a potential to enhance cancer detectability and differential diagnosis by ultrasonographic examinations and intraoperative fluorescence imaging through visualization of stasis of bile-excreting imaging agents in and/or around hepatic tumors. However, further technical

Photoacoustic tomography of human hepatic malignancies using intraoperative indocyanine green fluorescence imaging.

Science.gov (United States)

Miyata, Akinori; Ishizawa, Takeaki; Kamiya, Mako; Shimizu, Atsushi; Kaneko, Junichi; Ijichi, Hideaki; Shibahara, Junji; Fukayama, Masashi; Midorikawa, Yutaka; Urano, Yasuteru; Kokudo, Norihiro

2014-01-01

Recently, fluorescence imaging following the preoperative intravenous injection of indocyanine green has been used in clinical settings to identify hepatic malignancies during surgery. The aim of this study was to evaluate the ability of photoacoustic tomography using indocyanine green as a contrast agent to produce representative fluorescence images of hepatic tumors by visualizing the spatial distribution of indocyanine green on ultrasonographic images. Indocyanine green (0.5 mg/kg, intravenous) was preoperatively administered to 9 patients undergoing hepatectomy. Intraoperatively, photoacoustic tomography was performed on the surface of the resected hepatic specimens (n = 10) under excitation with an 800 nm pulse laser. In 4 hepatocellular carcinoma nodules, photoacoustic imaging identified indocyanine green accumulation in the cancerous tissue. In contrast, in one hepatocellular carcinoma nodule and five adenocarcinoma foci (one intrahepatic cholangiocarcinoma and 4 colorectal liver metastases), photoacoustic imaging delineated indocyanine green accumulation not in the cancerous tissue but rather in the peri-cancerous hepatic parenchyma. Although photoacoustic tomography enabled to visualize spatial distribution of ICG on ultrasonographic images, which was consistent with fluorescence images on cut surfaces of the resected specimens, photoacoustic signals of ICG-containing tissues decreased approximately by 40% even at 4 mm depth from liver surfaces. Photoacoustic tomography using indocyanine green also failed to identify any hepatocellular carcinoma nodules from the body surface of model mice with non-alcoholic steatohepatitis. In conclusion, photoacoustic tomography has a potential to enhance cancer detectability and differential diagnosis by ultrasonographic examinations and intraoperative fluorescence imaging through visualization of stasis of bile-excreting imaging agents in and/or around hepatic tumors. However, further technical advances are needed

SU-E-I-73: Clinical Evaluation of CT Image Reconstructed Using Interior Tomography

International Nuclear Information System (INIS)

Zhang, J; Ge, G; Winkler, M; Cong, W; Wang, G

2014-01-01

Purpose: Radiation dose reduction has been a long standing challenge in CT imaging of obese patients. Recent advances in interior tomography (reconstruction of an interior region of interest (ROI) from line integrals associated with only paths through the ROI) promise to achieve significant radiation dose reduction without compromising image quality. This study is to investigate the application of this technique in CT imaging through evaluating imaging quality reconstructed from patient data. Methods: Projection data were directly obtained from patients who had CT examinations in a Dual Source CT scanner (DSCT). Two detectors in a DSCT acquired projection data simultaneously. One detector provided projection data for full field of view (FOV, 50 cm) while another detectors provided truncated projection data for a FOV of 26 cm. Full FOV CT images were reconstructed using both filtered back projection and iterative algorithm; while interior tomography algorithm was implemented to reconstruct ROI images. For comparison reason, FBP was also used to reconstruct ROI images. Reconstructed CT images were evaluated by radiologists and compared with images from CT scanner. Results: The results show that the reconstructed ROI image was in excellent agreement with the truth inside the ROI, obtained from images from CT scanner, and the detailed features in the ROI were quantitatively accurate. Radiologists evaluation shows that CT images reconstructed with interior tomography met diagnosis requirements. Radiation dose may be reduced up to 50% using interior tomography, depending on patient size. Conclusion: This study shows that interior tomography can be readily employed in CT imaging for radiation dose reduction. It may be especially useful in imaging obese patients, whose subcutaneous tissue is less clinically relevant but may significantly increase radiation dose

Diffuse optical tomography for breast cancer imaging guided by computed tomography: A feasibility study.

Science.gov (United States)

Baikejiang, Reheman; Zhang, Wei; Li, Changqing

2017-01-01

Diffuse optical tomography (DOT) has attracted attentions in the last two decades due to its intrinsic sensitivity in imaging chromophores of tissues such as hemoglobin, water, and lipid. However, DOT has not been clinically accepted yet due to its low spatial resolution caused by strong optical scattering in tissues. Structural guidance provided by an anatomical imaging modality enhances the DOT imaging substantially. Here, we propose a computed tomography (CT) guided multispectral DOT imaging system for breast cancer imaging. To validate its feasibility, we have built a prototype DOT imaging system which consists of a laser at the wavelength of 650 nm and an electron multiplying charge coupled device (EMCCD) camera. We have validated the CT guided DOT reconstruction algorithms with numerical simulations and phantom experiments, in which different imaging setup parameters, such as projection number of measurements and width of measurement patch, have been investigated. Our results indicate that an air-cooling EMCCD camera is good enough for the transmission mode DOT imaging. We have also found that measurements at six angular projections are sufficient for DOT to reconstruct the optical targets with 2 and 4 times absorption contrast when the CT guidance is applied. Finally, we have described our future research plan on integration of a multispectral DOT imaging system into a breast CT scanner.

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.

Quantitative cone beam X-ray luminescence tomography/X-ray computed tomography imaging

International Nuclear Information System (INIS)

Chen, Dongmei; Zhu, Shouping; Chen, Xueli; Chao, Tiantian; Cao, Xu; Zhao, Fengjun; Huang, Liyu; Liang, Jimin

2014-01-01

X-ray luminescence tomography (XLT) is an imaging technology based on X-ray-excitable materials. The main purpose of this paper is to obtain quantitative luminescence concentration using the structural information of the X-ray computed tomography (XCT) in the hybrid cone beam XLT/XCT system. A multi-wavelength luminescence cone beam XLT method with the structural a priori information is presented to relieve the severe ill-posedness problem in the cone beam XLT. The nanophosphors and phantom experiments were undertaken to access the linear relationship of the system response. Then, an in vivo mouse experiment was conducted. The in vivo experimental results show that the recovered concentration error as low as 6.67% with the location error of 0.85 mm can be achieved. The results demonstrate that the proposed method can accurately recover the nanophosphor inclusion and realize the quantitative imaging

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

Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

International Nuclear Information System (INIS)

Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

2013-01-01

It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

Image quality in coronary computed tomography angiography

DEFF Research Database (Denmark)

Precht, Helle; Gerke, Oke; Thygesen, Jesper

2018-01-01

Background Computed tomography (CT) technology is rapidly evolving and software solution developed to optimize image quality and/or lower radiation dose. Purpose To investigate the influence of adaptive statistical iterative reconstruction (ASIR) at different radiation doses in coronary CT...

Some imaging characteristics of the dynamic spatial reconstructor X-ray scanner system

International Nuclear Information System (INIS)

Behrenbeck, T.; Sinak, L.J.; Robb, R.A.; Kinsey, J.H.; Ritman, E.L.

1984-01-01

In late 1979, the Dynamic Spatial Reconstructor (DSR), a multiple X-ray source, stop action, volume scanning imaging device was installed. At present, the operational characteristics and biomedical utility of the DSR are being evaluated. This research project involves scanning experimental animals and carefully selected patients with cardiovascular and pulmonary pathology. The DSR scanner utilizes a computerized transaxial tomography principle to generate images of transverse slices of the body. (Auth.)

Small-Animal Imaging Using Diffuse Fluorescence Tomography.

Science.gov (United States)

Davis, Scott C; Tichauer, Kenneth M

2016-01-01

Diffuse fluorescence tomography (DFT) has been developed to image the spatial distribution of fluorescence-tagged tracers in living tissue. This capability facilitates the recovery of any number of functional parameters, including enzymatic activity, receptor density, blood flow, and gene expression. However, deploying DFT effectively is complex and often requires years of know-how, especially for newer mutlimodal systems that combine DFT with conventional imaging systems. In this chapter, we step through the process of using MRI-DFT imaging of a receptor-targeted tracer in small animals.

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)

Radionuclide imaging with coded apertures and three-dimensional image reconstruction from focal-plane tomography

International Nuclear Information System (INIS)

Chang, L.T.

1976-05-01

Two techniques for radionuclide imaging and reconstruction have been studied;; both are used for improvement of depth resolution. The first technique is called coded aperture imaging, which is a technique of tomographic imaging. The second technique is a special 3-D image reconstruction method which is introduced as an improvement to the so called focal-plane tomography

Amyloid-β positron emission tomography imaging probes

DEFF Research Database (Denmark)

Kepe, Vladimir; Moghbel, Mateen C; Långström, Bengt

2013-01-01

, a number of factors appear to preclude these probes from clinical utilization. As the available "amyloid specific" positron emission tomography imaging probes have failed to demonstrate diagnostic value and have shown limited utility for monitoring therapeutic interventions in humans, a debate...

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

Science.gov (United States)

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

2014-12-01

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

Introduction to 2D and 3D tomographic methods based on straight line propagation: X-ray, emission and ultrasonic tomography

International Nuclear Information System (INIS)

Peyrin, F.; Magnin, I.; Garnero, L.

1996-01-01

This paper presents the basic principles of computerized tomography (CT), and its evolution towards three dimensional (3D) imaging. Since the modeling of CT reconstruction relies on the Radon transform, its definition and major properties are first recalled. After a brief summary on conventional 2D methods, we present the imaging principles for two modalities appropriated to this modeling: X-Ray and emission tomography. We describe the evolution of the instrumentation for these two techniques, and emphasize the approximations introduced by a modeling using the Radon transform taking into account the physics of the problem. We also describe the principles of ultrasonic tomography systems, and their major differences with the two previous techniques. At last, we formulate the general problematic of 3D image reconstruction from 2D projections. We consider four classes of reconstruction methods corresponding to the classification to the classification chosen for the synthetic presentation of methods, accompanying this paper. (authors)

imaging volcanos with gravity and muon tomography measurements

Science.gov (United States)

Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; Deroussi, Sébastien; Dufour, Fabrice; de Bremond d'Ars, Jean; Ianigro, Jean-Christophe; Gardien, Serge; Girerd, Claude

2015-04-01

Both muon tomography and gravimetry are geohysical methods that provide information on the density structure of the Earth's subsurface. Muon tomography measures the natural flux of cosmic muons and its attenuation produced by the screening effect of the rock mass to image. Gravimetry generally consists in measurements of the vertical component of the local gravity field. Both methods are linearly linked to density, but their spatial sensitivity is very different. Muon tomography essentially works like medical X-ray scan and integrates density information along elongated narrow conical volumes while gravimetry measurements are linked to density by a 3-dimensional integral encompassing the whole studied domain. We show that gravity data are almost useless to constrain the density structure in regions sampled by more than two muon tomography acquisitions. Interestingly the resolution in deeper regions not sampled by muon tomography is significantly improved by joining the two techniques. Examples taken from field experiments performed on La Soufrière of Guadeloupe volcano are discussed.

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

Science.gov (United States)

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

2014-05-01

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

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)

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.

Review methods for image segmentation from computed tomography images

International Nuclear Information System (INIS)

Mamat, Nurwahidah; Rahman, Wan Eny Zarina Wan Abdul; Soh, Shaharuddin Cik; Mahmud, Rozi

2014-01-01

Image segmentation is a challenging process in order to get the accuracy of segmentation, automation and robustness especially in medical images. There exist many segmentation methods that can be implemented to medical images but not all methods are suitable. For the medical purposes, the aims of image segmentation are to study the anatomical structure, identify the region of interest, measure tissue volume to measure growth of tumor and help in treatment planning prior to radiation therapy. In this paper, we present a review method for segmentation purposes using Computed Tomography (CT) images. CT images has their own characteristics that affect the ability to visualize anatomic structures and pathologic features such as blurring of the image and visual noise. The details about the methods, the goodness and the problem incurred in the methods will be defined and explained. It is necessary to know the suitable segmentation method in order to get accurate segmentation. This paper can be a guide to researcher to choose the suitable segmentation method especially in segmenting the images from CT scan

Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: Comparison with catheter angiography

International Nuclear Information System (INIS)

Moore, R.K.G.; Sampson, C.; MacDonald, S.; Moynahan, C.; Groves, D.; Chester, M.R.

2005-01-01

AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor

Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: Comparison with catheter angiography

Energy Technology Data Exchange (ETDEWEB)

Moore, R.K.G. [Cardiothoracic Centre, Liverpool (United Kingdom)]. E-mail: moore@roger.go-legend.net; Sampson, C. [Cardiothoracic Centre, Liverpool (United Kingdom); MacDonald, S. [Cardiothoracic Centre, Liverpool (United Kingdom); Moynahan, C. [Cardiothoracic Centre, Liverpool (United Kingdom); Groves, D. [National Refractory Angina Centre, Liverpool (United Kingdom); Chester, M.R. [National Refractory Angina Centre, Liverpool (United Kingdom)

2005-09-01

AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor.

Three-dimensional multifunctional optical coherence tomography for skin imaging

Science.gov (United States)

Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki

2016-02-01

Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

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)

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)

Computerized three-dimensional normal atlas

International Nuclear Information System (INIS)

Mano, Isamu; Suto, Yasuzo; Suzuki, Masataka; Iio, Masahiro.

1990-01-01

This paper presents our ongoing project in which normal human anatomy and its quantitative data are systematically arranged in a computer. The final product, the Computerized Three-Dimensional Normal Atlas, will be able to supply tomographic images in any direction, 3-D images, and coded information on organs, e.g., anatomical names, CT numbers, and T 1 and T 2 values. (author)

Positron emission tomography tracers for imaging angiogenesis

International Nuclear Information System (INIS)

Haubner, Roland; Beer, Ambros J.; Wang, Hui; Chen, Xiaoyuan

2010-01-01

Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or α v β 3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging α v β 3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

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)

Computerized tomography using fast neutrons

International Nuclear Information System (INIS)

Maier-Schuler, P.

1992-03-01

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

Novel precision enhancement algorithm with reduced image noise in cosmic muon tomography applications

Directory of Open Access Journals (Sweden)

Lee Sangkyu

2016-01-01

Full Text Available In this paper, we present a new algorithm that improves muon-based generated tomography images with increased precision and reduced image noise applicable to the detection of nuclear materials. Cosmic muon tomography is an interrogation-based imaging technique that, over the last decade, has been frequently employed for the detection of high-Z materials. This technique exploits a magnitude of cosmic muon scattering angles in order to construct an image. The scattering angles of the muons striking the geometry of interest are non-uniform, as cosmic muons vary in energy. The randomness of the scattering angles leads to significant noise in the muon tomography image. GEANT4 is used to numerically create data on the momenta and positions of scattered muons in a predefined geometry that includes high-Z materials. The numerically generated information is then processed with the point of closest approach reconstruction method to construct a muon tomography image; statistical filters are then developed to refine the point of closest approach reconstructed images. The filtered images exhibit reduced noise and enhanced precision when attempting to identify the presence of high-Z materials. The average precision from the point of closest approach reconstruction method is 13 %; for the integrated method, 88 %. The filtered image, therefore, results in a seven-fold improvement in precision compared to the point of closest approach reconstructed image.

In-Line Phase-Contrast X-ray Imaging and Tomography for Materials Science.

Science.gov (United States)

Mayo, Sheridan C; Stevenson, Andrew W; Wilkins, Stephen W

2012-05-24

X-ray phase-contrast imaging and tomography make use of the refraction of X-rays by the sample in image formation. This provides considerable additional information in the image compared to conventional X-ray imaging methods, which rely solely on X-ray absorption by the sample. Phase-contrast imaging highlights edges and internal boundaries of a sample and is thus complementary to absorption contrast, which is more sensitive to the bulk of the sample. Phase-contrast can also be used to image low-density materials, which do not absorb X-rays sufficiently to form a conventional X-ray image. In the context of materials science, X-ray phase-contrast imaging and tomography have particular value in the 2D and 3D characterization of low-density materials, the detection of cracks and voids and the analysis of composites and multiphase materials where the different components have similar X-ray attenuation coefficients. Here we review the use of phase-contrast imaging and tomography for a wide variety of materials science characterization problems using both synchrotron and laboratory sources and further demonstrate the particular benefits of phase contrast in the laboratory setting with a series of case studies.

Simulated annealing image reconstruction for positron emission tomography

International Nuclear Information System (INIS)

Sundermann, E.; Lemahieu, I.; Desmedt, P.

1994-01-01

In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors)

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%.

Computerized detection method for asymptomatic white matter lesions in brain screening MR images using a clustering technique

International Nuclear Information System (INIS)

Kunieda, Takuya; Uchiyama, Yoshikazu; Hara, Takeshi

2008-01-01

Asymptomatic white matter lesions are frequently identified by the screening system known as Brain Dock, which is intended for the detection of asymptomatic brain diseases. The detection of asymptomatic white matter lesions is important because their presence is associated with an increased risk of stroke. Therefore, we have developed a computerized method for the detection of asymptomatic white matter lesions in order to assist radiologists in image interpretation as a ''second opinion''. Our database consisted of T 1 - and T 2 -weighted images obtained from 73 patients. The locations of the white matter lesions were determined by an experienced neuroradiologist. In order to restrict the area to be searched for white matter lesions, we first segmented the cerebral region in T 1 -weighted images by applying thresholding and region-growing techniques. To identify the initial candidate lesions, k-means clustering with pixel values in T 1 - and T 2 -weighted images was applied to the segmented cerebral region. To eliminate false positives (FPs), we determined the features, such as location, size, and circularity, of each of the initial candidate lesions. Finally, a rule-based scheme and a quadratic discriminant analysis with these features were employed to distinguish between white matter lesions and FPs. The results showed that the sensitivity for the detection of white matter lesions was 93.2%, with 4.3 FPs per image, suggesting that our computerized method may be useful for the detection of asymptomatic white matter lesions in T 1 - and T 2 -weighted images. (author)

Ectopic pregnancy: pictorial essay focusing on computed tomography and magnetic resonance imaging findings

International Nuclear Information System (INIS)

Febronio, Eduardo Miguel; Rosas, George de Queiroz; D'Ippolito, Giuseppe

2012-01-01

The objective of the present study is to describe key computed tomography and magnetic resonance imaging findings in patients with acute abdominal pain caused by ectopic pregnancy. For this purpose, two radiologists consensually selected and analyzed computed tomography and magnetic resonance imaging studies performed in female patients with acute abdominal pain caused by proven ectopic pregnancy in the period between January 2010 and December 2011. The imaging diagnosis of ectopic pregnancy is usually obtained by ultrasonography, however, with the increasing use of computed tomography and magnetic resonance imaging in the assessment of patients with acute abdomen of gynecological origin it is necessary that the radiologist becomes familiar with the main findings observed at these diagnostic methods. (author)

Ectopic pregnancy: pictorial essay focusing on computed tomography and magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Febronio, Eduardo Miguel; Rosas, George de Queiroz; D' Ippolito, Giuseppe [Escola Paulista de Medicina - Universidade Federal de Sao Paulo (EPM-Unifesp), Sao Paulo, SP (Brazil). Dept. of Imaging Diagnosis; Cardia, Patricia Prando, E-mail: giuseppe_dr@uol.com.br [Centro Radiologico Campinas, Campinas, SP (Brazil)

2012-09-15

The objective of the present study is to describe key computed tomography and magnetic resonance imaging findings in patients with acute abdominal pain caused by ectopic pregnancy. For this purpose, two radiologists consensually selected and analyzed computed tomography and magnetic resonance imaging studies performed in female patients with acute abdominal pain caused by proven ectopic pregnancy in the period between January 2010 and December 2011. The imaging diagnosis of ectopic pregnancy is usually obtained by ultrasonography, however, with the increasing use of computed tomography and magnetic resonance imaging in the assessment of patients with acute abdomen of gynecological origin it is necessary that the radiologist becomes familiar with the main findings observed at these diagnostic methods. (author)

Appropriate use of diagnostic imaging

Energy Technology Data Exchange (ETDEWEB)

Palmer, P.E.S.; Cockshott, W.P.

1984-11-16

This article discusses ways in which more appropriate use can be made of roentgenography with a resulting decrease in radiation doses to the patient population. The authors recommend that fewer films be made and that traditional roentgenography be replaced with endoscopy, ultrasound, computerized tomography, or angiography where appropriate. They also recommend that medical schools and medical subspecialty groups study the World Health Organization document which provides indications for diagnostic imaging, the choice of procedure and the limitations of each.

Paul and Juhl's essentials of radiologic imaging. Fifth edition

International Nuclear Information System (INIS)

Anon.

1987-01-01

This book discusses the image processing technology in nuclear medicine. The techniques discussed are biomedical radiography, NMR imaging, ultrasonography and computerized tomography as used for diagnostic purpose of skeletal diseases; brain and spinal cord diseases; abdomen and gastrointestinal tract diseases; urinary and genital tract diseases and chest and face diseases. Infections diseases of chest and bone are described and specifically described in ultrasonography of uterine diseases and evaluation of pregnancy. Congenital malformation of skeleton and hereditary diseases are also discussed

Usefulness of computerized method for lung nodule detection on digital chest radiographs using similar subtraction images from different patients

International Nuclear Information System (INIS)

Aoki, Takatoshi; Oda, Nobuhiro; Yamashita, Yoshiko; Yamamoto, Keiji; Korogi, Yukunori

2012-01-01

Purpose: The purpose of this study is to evaluate the usefulness of a novel computerized method to select automatically the similar chest radiograph for image subtraction in the patients who have no previous chest radiographs and to assist the radiologists’ interpretation by presenting the “similar subtraction image” from different patients. Materials and methods: Institutional review board approval was obtained, and the requirement for informed patient consent was waived. A large database of approximately 15,000 normal chest radiographs was used for searching similar images of different patients. One hundred images of candidates were selected according to two clinical parameters and similarity of the lung field in the target image. We used the correlation value of chest region in the 100 images for searching the most similar image. The similar subtraction images were obtained by subtracting the similar image selected from the target image. Thirty cases with lung nodules and 30 cases without lung nodules were used for an observer performance test. Four attending radiologists and four radiology residents participated in this observer performance test. Results: The AUC for all radiologists increased significantly from 0.925 to 0.974 with the CAD (P = .004). When the computer output images were available, the average AUC for the residents was more improved (0.960 vs. 0.890) than for the attending radiologists (0.987 vs. 0.960). Conclusion: The novel computerized method for lung nodule detection using similar subtraction images from different patients would be useful to detect lung nodules on digital chest radiographs, especially for less experienced readers.

Imaging of sciatica

International Nuclear Information System (INIS)

Anda, S.

1993-01-01

Cotugno described the clinical entity of sciatica in 1764. However, the association between sciatica and compression of lumbar nerve roots was not realized until the 1920s. Back surgery for herniated nucleus pulposus then became fashionable, and plain radiography and myelography enabled preoperative mapping. Recently other imaging techniques have emerged, such as computerized tomography and magnetic resonance imaging. This has increased the knowledge of the etiology of lumbar root compressions, and invasive therapies for sciatica have become more diversified. It is easy to lose perspective among the available imaging procedures and therapeutic techniques. The aim of this paper is to present the current status from a historical point of view, with special emphasis on the most common imaging methods for the investigation of lumbosacral radiculopathies. 48 refs., 4 figs

Computerized Interpretation of Dynamic Breast MRI

National Research Council Canada - National Science Library

Chen, Weijie; Giger, Maryellen Lissak

2005-01-01

... and prognosis of breast cancer. The research involves investigation of automatic methods for image artifacts correction, tumor segmentation, and extraction of computerized features that help distinguish between benign and malignant lesions...

Anatomical Variations of Carotid Artery and Optic Nerve in Sphenoid Sinus Using Computerized Tomographic Imaging

Directory of Open Access Journals (Sweden)

Nikakhlagh

2014-12-01

Full Text Available Background Sphenoid sinus is surrounded by many vital vascular and nervous structures. In more than 20% of patients with chronic sinusitis, involvement of sphenoid sinus has been observed. Besides, sphenoid sinus is an appropriate route to access anterior and middle cranial fossa in surgery. Therefore, it is important to have an adequate knowledge about the contents of sphenoid sinus and its proximity for nasal endoscopy, sinus surgeries and neurosurgeries. Objectives The aim of this study was to study sphenoid sinus proximity with carotid artery and the optic nerve using computerized tomographic imaging. Materials and Methods In this prospective study, computerized tomographic images of sphenoid sinus of patients referred to Imam Khomeini and Apadana hospitals were studied. The images were studied regarding any bulging, as well as not having a bone covering in sphenoid sinus regarding internal carotid artery and optic nerve. Furthermore, unilateralness or bilateralness of their relationships was studied. Results Among 468 coronal and axial CT scan images of sphenoid sinus, 365 (78% showed post-sellar pneumatization and 103 (22% pre-sellar pneumatization. Regarding existence of internal septa, 346 (74% cases showed multiple septation, and the remaining images were reported to have a single septum. According to the reports of CT scan images, the existence of bulging as a result of internal carotid artery and uncovered artery were 4.22% and 5.8% in the right sinus, 4.9% and 5.4% in the left sinus, and 4.34% and 4.6% in both sinuses, respectively. According to the reports of CT scan images, existence of bulging as a result of optic nerve and uncovered nerve were 5.7% and 4.3% in the right sinus, 6% and 5.4% in the left sinus, and 12% and 3.2% in both sinuses, respectively. Conclusions Due to variability of sphenoid sinus pneumatization and the separator blade of the two sinus cavities, careful attention is required during sinus surgery to avoid

Color camera computed tomography imaging spectrometer for improved spatial-spectral image accuracy

Science.gov (United States)

Wilson, Daniel W. (Inventor); Bearman, Gregory H. (Inventor); Johnson, William R. (Inventor)

2011-01-01

Computed tomography imaging spectrometers ("CTIS"s) having color focal plane array detectors are provided. The color FPA detector may comprise a digital color camera including a digital image sensor, such as a Foveon X3.RTM. digital image sensor or a Bayer color filter mosaic. In another embodiment, the CTIS includes a pattern imposed either directly on the object scene being imaged or at the field stop aperture. The use of a color FPA detector and the pattern improves the accuracy of the captured spatial and spectral information.

Computerized videodefecography versus defecography: do we need radiographs?

Directory of Open Access Journals (Sweden)

Carlos Walter Sobrado

Full Text Available CONTEXT AND OBJECTIVE: Defecography has been recognized as a valuable method for evaluating patients with evacuation disorders. It consists of the use of static radiography and fluoroscopy to record different situations within anorectal dynamics. Conventionally, rectal parameters are measured using radiograms. It is rare for fluoroscopy alone to be used. Computer software has been developed with the specific aim of calculating these measurements from digitized videotaped images obtained during fluoroscopy, without the need for radiographic film, thereby developing a computerized videodefecography method. The objective was thus to compare measurements obtained via computerized videodefecography with conventional measurements and to discuss the advantages of the new method. DESIGN AND SETTING: Prospective study at the radiology service of Hospital das Clínicas, Universidade de São Paulo. METHOD: Ten consecutive normal subjects underwent videodefecography. The anorectal angle, anorectal junction, puborectalis muscle length, anal canal length and degree of anal relaxation were obtained via the conventional method (using radiography film and via computerized videodefecography using the ANGDIST software. Measurement and analysis of these parameters was performed by two independent physicians. RESULTS: Statistical analysis confirmed that the measurements obtained through direct radiography film assessment and using digital image analysis (computerized videodefecography were equivalent. CONCLUSIONS: Computerized videodefecography is equivalent to the traditional defecography examination. It has the advantage of offering reduced radiation exposure through saving on the use of radiography.

First image from a combined positron emission tomography and field-cycled MRI system.

Science.gov (United States)

Bindseil, Geron A; Gilbert, Kyle M; Scholl, Timothy J; Handler, William B; Chronik, Blaine A

2011-07-01

Combining positron emission tomography and MRI modalities typically requires using either conventional MRI with a MR-compatible positron emission tomography system or a modified MR system with conventional positron emission tomography. A feature of field-cycled MRI is that all magnetic fields can be turned off rapidly, enabling the use of conventional positron emission tomography detectors based on photomultiplier tubes. In this demonstration, two photomultiplier tube-based positron emission tomography detectors were integrated with a field-cycled MRI system (0.3 T/4 MHz) by placing them into a 9-cm axial gap. A positron emission tomography-MRI phantom consisting of a triangular arrangement of positron-emitting point sources embedded in an onion was imaged in a repeating interleaved sequence of ∼1 sec MRI then 1 sec positron emission tomography. The first multimodality images from the combined positron emission tomography and field-cycled MRI system show no additional artifacts due to interaction between the systems and demonstrate the potential of this approach to combining positron emission tomography and MRI. Copyright © 2010 Wiley-Liss, Inc.

An imaging atlas of human anatomy

International Nuclear Information System (INIS)

Weir, J.; Abrahams, P.H.

1993-01-01